Welcome!

If you are feeding all the speakers from a single full-frequency mix, you should always employ crossovers between the subs/mids and the mids/tops. These crossovers need to be of the Linkwitz-Riley type to keep the phase response consistent through the crossover frequency range. There is a good introductory Rane article on this subject.

However, you said that you are doing this for live sound, and so there is another method you should consider for driving the subs. This is called the aux-fed sub, where you generate a specific mono mix for your subs in your mixer and send it out through one of the mixer's Aux outputs. The mains/tops are fed using their normal crossover from the mixer main outputs. Doing it this way allows you to control which sound sources are put through the subs, and in many cases, it can make a sub/mid crossover unnecessary. For example, you could choose to send just the kick drum microphone and the guitar bass DI to the subs and not to the mains, thus removing a great deal of LF clutter from the main and top loudspeakers. It takes a bit of extra mixing skill to get the balance right and to mute the subs between songs, but the extra clarity you get through the main loudspeakers by not having to deal with heavy low-frequency components can be well worth the extra effort.

Good luck!

Hi Cheryl, and welcome to Recording.org.

I realize it's not your gear, but model numbers would be useful if you have access to them.

I believe you're right about avoiding the overlapping low-mids, and the subs not needing any help from the full range speakers.

Mackie powered speakers have perfectly adequate crossovers built into them, specifically tailored for what each cabinet does best. Is there a specific reason you want to go outside the box?

If it's simply because you don't want the overlap between the sub and the full range; connect your XLR mains from the mixer to the input(s) on the back of the sub(s), and then jump short XLR cables out from the sub to the full range cabinets using the sub's "HIGH PASS" Output connectors. That will eliminate any overlapping frequencies.

You would only use the "FULL RANGE" Output(s) to jump to any additional sub cabinet(s), and repeat as needed.

For instance the Mackie Thump18s has designated a fixed crossover point of 140Hz.
The SRM series subs are set at 115Hz, but in "VAR" (variable) mode, you can dial the HPF anywhere from 60Hz to 120Hz. And as long as you use the "HIGH PASS" outputs, there's not going to be any overlap.

If for whatever reason the overlap between 140Hz and 35Hz is desirable, then that's another case where you would simply connect your tops to the "FULL RANGE" Outputs on the back of the sub, and deal with the mess the overlapping low-mids is likely to cause with EQ.

You could use Master Fader to adjust the crossover point by incorporating Post-Fader Auxes with the appropriate High-Pass-Filters and Low-Pass-Filters engaged, but it would complicate the cabling and iPad mixing. It complicates the cabling by requiring a homerun from the mixer Aux Out to the sub, plus a homerun to the full range from the mixer Main Output(s). If you're running in stereo, you'll need 4 homeruns. If you're running in mono, you would also have the option of jumping sub to sub, and full range to full range. To me, it complicates the iPad mixing just because of the limited screen space you get with Master Fader. The Auxes have EQ and HPF and LPF, the Subgroups only have EQ, the VCAs have neither.

In my option it wouldn't yield enough benefit to justify doing it unless you really needed to constantly monitor and re-balance the subs vs. tops levels from the iPad.

Also, is "deafeningly loud" what the band is shooting for? ( I know some that would be )

Boswell, post: 448548, member: 29034 wrote: Welcome!

Thanks! Quick response!

If you are feeding all the speakers from a single full-frequency mix...

The speakers are Mackie powered 3-way full range, and Mackie powered subwoofer. Apparently they have something similar to the aux-fed sub but with some differences from that article.

The subs are low-passed with the graphic EQ on the aux. The full range mains have a house curve on the graphic with mild broad bass boost slope of about -3dB/decade or so up to about 1KHz. The subs are rated to about 30Hz and the mains rated to about 35Hz.

The mains/tops are fed using their normal crossover from the mixer main outputs.

The mains are full range speakers and the mix they get is also full range. It includes the bass and kick, with the input faders on them separated between main and sub. Also, the output faders on the mains and aux sub are independent rather than ganged in a VCA.

I was considering using the l/r main input fader to control the bass and kick levels on the aux/sub channel so that the tonal balance remains constant. However, the aux send may be set to post-fader as in the article already and if so it is already OK. I did not check and did not know to check at the time because I was unfamiliar with the gear.

I was also considering ganging the main and sub output faders on a VCA to make the output levels track.

Doing it this way allows you to control which sound sources are put through the subs, and in many cases, it can make a sub/mid crossover unnecessary. For example, you could choose to send just the kick drum microphone and the guitar bass DI to the subs and not to the mains, thus removing a great deal of LF clutter from the main and top loudspeakers.

This seems to be the original intent of the setup they are currently using.

It takes a bit of extra mixing skill to get the balance right and to mute the subs between songs, but the extra clarity you get through the main loudspeakers by not having to deal with heavy low-frequency components can be well worth the extra effort.

Good luck!

Yes well the problem is the skill. I have minimal experience at this. I was a warm body where there was none before.

Apparently the drummer who set up this mix on his equipment also has minimal experience at this.

So, now that I understand aux-fed sub (thanks for that!) I will have to go do some more reading and experimentation. It seems that the aux fed sub is superior for live sound so I will try to tune it that way.

dvdhawk, post: 448549, member: 36047 wrote: Hi Cheryl, and welcome to Recording.org.

I realize it's not your gear, but model numbers would be useful if you have access to them.

SA1530z https://supportloudtech.netx.net/loud-public/#asset/10579
SWA1801z https://supportloudtech.netx.net/loud-public/#asset/10600
DL1608 https://supportloudtech.netx.net/loud-public/#/asset/9115
Master Fader http://mackie.com/products/master-fader

The subwoofers are designed to mate with the SA1521z but for some reason the drummer bought the SA1530z, runs them full range, and stacks them on the subs without a pole.

Is there a specific reason you want to go outside the box?

I am trying to bring an existing setup inside the box. Since I had never before seen the aux fed sub configuration they are using, I was confused by it, so I started looking for more information here.

If it's simply because you don't want the overlap between the sub and the full range; connect your XLR mains

The drummer seems resistant to making large changes to the setup he has. I also think, after reading about aux fed sub, it is superior approach, plus they are most of the way there already.

I found this: Crossover with Matrix Outputs https://supportloudtech.netx.net/loud-public/#/asset/16525

but have not read it yet. Still trying to sort out the rest of the details, and I only have access to the iPad at gigs.

You could use Master Fader to adjust the crossover point by incorporating Post-Fader Auxes with the appropriate High-Pass-Filters and Low-Pass-Filters engaged,

The SWA1801z manual says it is 120Hz 12dB/octave crossover but does not state if the lowpass is active all the time or only when the highpass output connector is plugged in. I presume the lowpass is always in circuit?

If I try to run with this aux fed sub and the sub has its own crossover, what does that mean for linkwitz-riley? I would need to add another 12dB/octave low pass at 120Hz to the sub, and use a 24dB/octave highpass on the mains, with the frequency set to, what, 110Hz? Probably I need to tune it with a nearfield microphone and REW to do it properly?

but it would complicate the cabling and iPad mixing.

They are already running stereo mains and mono aux fed subs, I think.

To me, it complicates the iPad mixing just because of the limited screen space you get with Master Fader.

Yes, I noticed that at the last gig. I had to walk back the mains gradually toward the end of the night and that meant using the keyboard input screen because the sliders are just too coarse on the touchscreen, and I had to alternate back and forth between mains and subs to adjust by 0.5dB steps to keep the change smooth.

The Auxes have EQ and HPF and LPF, the Subgroups only have EQ, the VCAs have neither.

My impression was that I can use the independent EQ on the l/r main and aux/sub to set up a crossover and trim the frequency response while still using the VCA to gang the output faders. I can also still use the output compression on the mains and aux/sub. Is that correct?

Also, is "deafeningly loud" what the band is shooting for? ( I know some that would be )

Just about every band plays too loud for me, but yes, this band wants to feel it rattle through their bones. We are negotiating a compromise where I keep my earplugs in most of the time and try not to cause too much hearing damage for everyone else by moderating the volume as best I can without destroying the tactile completely.

CherylJosie, post: 448552, member: 50446 wrote: Just about every band plays too loud for me, but yes, this band wants to feel it rattle through their bones. We are negotiating a compromise where I keep my earplugs in most of the time and try not to cause too much hearing damage for everyone else by moderating the volume as best I can without destroying the tactile completely.

A common problem, unfortunately, and kind of a sign of their level of professionalism... I don't know why club bands are so often resistant to the fact that, the more in control of their stage volume they are, the better they will play, the more they'll be able to hear each other, and...the more control the FOH engineer has; which ultimately, allows you to provide better FOH mixes. And, the better the fronts sound, the more people listening will enjoy the band.

I've seen bands where the guitar amps are stationed behind the players, and are blowing into the backs of their knees; so they complain that they can't hear themselves, so, they turn up.... but at a stage height of 3' or so, the people out in the audience are getting a full-frontal blast from the amps on stage.

Until you get them to rein in the stage volume, you'll only ever be able to do so much, regardless of how good the PA is, or the way it is set up.

Make sure they understand that you are not responsible for what they do on stage, and don't let them attempt to blame bad mixes on you, either, if the stage volume is such that it's an ungodly wall of white noise.
There's nothing you can do if the band is so loud that you've got every fader on the FOH mixer off ...and it's still too loud.

Oh, and welcome to RO, Cheryl. :)

You've got several options here, Cheryl, but also several constraints, not the least of which is that your drummer set the system up and sounds as though he would not easily be convinced that a major change to the loudspeaker configuration is necessary. Dave (dvdhawk) has given an excellent view from someone with much wider familiarity with the range of Mackie gear than I have (it is not as common on this side of the Atlantic), and you have also explained more about how the system is currently configured.

There was one thing you mentioned that really hit a nerve with me, and that is the use of graphic EQ units to perform loudspeaker crossover functions. This is normally a no-no, as the phase characteristics of narrow-band graphic EQs are not conducive to a smooth phase response through the crossover regions. The big exception to that is if you are talking about digital graphic EQs implemented using linear-phase FIR filters, where, by definition, the phase is controlled. However, FIR filters are more often used in studio mixdowns and not generally suited to live work because of the time delays they inject.

You seem to have got a handle on the control of the balance between the subs and the mains, but possibly some further experimentation with VCAs (if your mixer has them) to control both at once would allow a more peaceful FOH workflow.

My recommendation for experiment would be to continue with the aux-fed subs, feeding the kick and bass through them, but don't send these instruments to the mids/tops. Doing that would allow you to dispense with additional crossovers altogether, just using the LPFs built into the subs and feeding the remainder of the mix full-range to the mids/tops. In a lecture course I used to give many years ago, I had a demonstration where I sent a 1KHz sinewave to an 8" loudspeaker in a good-sized cabinet and then used a microphone in front of the speaker to feed a spectrum analyser. The 1KHz came out relatively clearly as a single line on the analyser until I mixed an unrelated 40Hz sinewave in with the 1KHz. The 40Hz was below what the loudspeaker cabinet would reproduce, but the loudspeaker cone was nevertheless going through the motions of responding to both the frequencies. The result in the spectrum analyser was that the 1KHz line got broadened by 80Hz due to the Doppler effect of the cone movement, an effect you could hear. This was to illustrate that, if you want purity of mid/high frequencies, you should try to avoid putting large-amplitude low frequencies through the same physical speakers.

CherylJosie, post: 448542, member: 50446 wrote: I am considering setting up a crossover and high-passing the mains but not sure if this is wise, for many reasons.

To me a dedicated crossover is the best choice. it can be tuned to the speaker array and even if you change the mixer you'll get the same accurate results. (and no phase issues like my friends and I fear.)

Boswell, post: 448554, member: 29034 wrote: My recommendation for experiment would be to continue with the aux-fed subs, feeding the kick and bass through them, but don't send these instruments to the mids/tops.

Bos, I'm not sure about this. to make tests yes but for a gig ?? There is a lot HM & HF needed for a bass drum pressence and also for the bass.
What I suggest 2 options ;

1. Make use of 2 linear phase EQ if it's a digital board (one for the mains and one for the Aux Sub) and fine tune a crossover that way.
2. Let the mains full range (to give some lows to pianos or other instruments) and make the SUB Aux pre fader, then cut the lows on the bass and bassdrum strip so they don't output low freq to the mains and use a low pass on the AUX Sub.
   No need to say an external dedicated crossover is a better choice.
   Also an option, you can still seperate the freq using the sub aux, but use the external crossover to remove lows to the top speakers.

   EDIT : Some external crossover can receive 2 full range signals. So you can send the mains and the Aux sub without eq and the crossover does the job ;)

pcrecord, post: 448556, member: 46460 wrote: Bos, I'm not sure about this. to make tests yes but for a gig ?? There is a lot HM & HF needed for a bass drum pressence and also for the bass.

Yes, as an experiment. Sorry, I didn't emphasise that.

For gigs, I have used a mixer to split the kick/bass in frequency by using up two mixer channels for each, then sending only the low end to the subs and the remaining highs to the standard mid/top mix. But phase problems are the enemy. I ended up doing it with analogue crossover boxes (Linkwitz-Riley filters) in the external insert loops, with the high/low outputs going to the returns on the two separate mixer channels.

I do a few big shows in the summer and the best setup I had to work with was a Yamaha M7CL (which has a dedicated sub fader)
Mains and sub output of the mixer are sent to tuned crossovers which feed a line array. Man it's an easy job !!

DonnyThompson, post: 448553, member: 46114 wrote: A common problem, unfortunately, and kind of a sign of their level of professionalism... I don't know why club bands are so often resistant to the fact that, the more in control of their stage volume they are, the better they will play, the more they'll be able to hear each other, and...the more control the FOH engineer has; which ultimately, allows you to provide better FOH mixes. And, the better the fronts sound, the more people listening will enjoy the band.

They ride the line between Reggae tactile and 'wall of sound' and in that respect are about average loudness, if still too loud.

The first gig I went to was a warehouse party and multiple bands all using the same equipment with the overhead doors open and most of us outside. They tested the limits of the system that time due to being isolated and having full autonomy. That is what I was referring to when saying that the system is unbearably loud. I was trying to point out that it seems the subs do not need any additional bass from the mains that should be highpassed.

I've seen bands where the guitar amps are stationed behind the players, and are blowing into the backs of their knees; so they complain that they can't hear themselves, so, they turn up.... but at a stage height of 3' or so, the people out in the audience are getting a full-frontal blast from the amps on stage.

Another band I hang with uses tiny amps with large speakers in them, set on the floor and angled up. Personally I am not a fan of the sound but the light small boxes are easy to move and mic.

Until you get them to rein in the stage volume, you'll only ever be able to do so much, regardless of how good the PA is, or the way it is set up.

I make that argument with virtually every band but I only find one in ten drummers that knows how to play fast AND light at the same time. Those needing to pound the drums seem to do it for the recoil as much as for the tactile.

In this case I think probably the drummer and the rest of the band just prefer the tactile for the Reggae dance feel. I think the audience does also.

I prefer drummers who not only keep the volume down but also take advantage of the lower level to spice up the dynamic range. It makes the music cut through better without drowning out conversation and it feels more satisfying to me when hard hits stand out because they stand alone. But that is not Reggae and not even pop. That is more suited to jazz and classical.

Make sure they understand that you are not responsible for what they do on stage, and don't let them attempt to blame bad mixes on you, either, if the stage volume is such that it's an ungodly wall of white noise.
There's nothing you can do if the band is so loud that you've got every fader on the FOH mixer off ...and it's still too loud.

Actually I am the one who is usually too critical, and sometimes too experimental, being inexperienced at this. They are just glad to have someone moving the faders for them.

Oh, and welcome to RO, Cheryl. :)

Thanks much, seems like a great community and I wish I found it sooner.

I think the main question is for you, Cheryl, .... do you enjoy doing it? Because you've already demonstrated a good grasp of the mission at hand, and if you're not careful, you might create a demand for your sound tech services if you've also got a musical ear. And honestly, there's very little 'upside' if you don't like the work. Your engineering mindset is serving you well in sorting through this, and I'll be surprised if you don't eclipse the PA owner by mid-week. Kudos to you for doing your homework and reading the manuals, it's a lost art.

You're doing great, but I'm going to just throw out some random notes for your consideration, and a couple questions at the end.

• If you have a PA system that's balanced and optimized based on the strengths of individual pieces, (i.e. using the HighPass out of the subs to avoid the low-mid overlap) I think you'll get much more predictable results (song to song, set to set, night to night, venue to venue). I'd try to make it as flat and efficient as possible regardless of input source(s). Otherwise, I feel like you will be forever chasing your tail as every adjustment has multiple results and consequences. Matrix and Aux technology is a beautiful and useful thing, but in my opinion, only in systems and venues well up the ladder from what you've described. And I feel like it would actually be a detriment to an admitted novice mixing, at least at first. More energy in the sub and low-midrange isn't going to be of any use to you without enough high-mid and horn level to balance it out.
• In your case, I think you can achieve the same net result as you would with the Aux or Matrix approach in a more pure way, by using the HPF on each input - with the added benefit of it being more tunable / adjustable, rather than 'all or none'. (meaning, included or excluded from the sub feed) So in other words, if you wanted a little electric guitar in the subs, set the HPF at 100Hz. If you don't want any of the acoustic guitar in the subs, set the HPF at 120Hz or above. As pcrecord points out, even the kick drum can be very present up to where the beater sound is between 3k - 5kHz. And as Boswell notes, using an EQ as a pseudo-crossover is likely to introduce unnecessary phase problems. If they're trying to milk every dB out of the system they can, a better solution would be an external active crossover along the lines of the dbx DriveRack family.
• One way or another, I'd really want to get those top cabinets a couple feet higher. If the PA is stacked on an elevated stage, they might be OK without any pole, tripod, or box. If they're stacked at floor-level, as soon as someone 5' 6" stands or dances in front of the 6ft. tall stacks, they will block virtually all of that stack's high freqs. from getting to the rest of the room. So the people up front are going to get drilled by the horns, and for the folks further back it will sound muffled and muddy. It's a good idea to get the horns a couple feet above head level.
• All you need to balance the levels of the sub vs. the full-range is an RTA app for your iPad. I use one by "Andrew Smith" in the App Store, that is very handy for realtime frequency analysis and easily accurate enough just using the iPad's internal mic. If you would like any more information about that, please feel free ask.

What genre of music do they play?
Can you can provide any details on number of vocals, and the rest of the instrumentation? (what all is mic'ed up)

Best of luck.

Boswell, post: 448554, member: 29034 wrote: You've got several options here, Cheryl, but also several constraints, not the least of which is that your drummer set the system up and sounds as though he would not easily be convinced that a major change to the loudspeaker configuration is necessary.

Perceptive of you. :)

Actually, I think time constraints and the freshness of the alliance, plus my lack of experience as well as his, have been the major obstacles. He seems receptive in the broader sense.

the use of graphic EQ units to perform loudspeaker crossover functions

Most layperson will not be aware of this so it is understandable and forgivable.

The big exception to that is if you are talking about digital graphic EQs

Thanks for that elaboration. My DSP days were long ago and sparse.

You seem to have got a handle on the control of the balance between the subs and the mains, but possibly some further experimentation with VCAs (if your mixer has them) to control both at once would allow a more peaceful FOH workflow.

That is the plan. DL1608 has four VCAs, and also has four submixes with EQ.

My recommendation for experiment would be to continue with the aux-fed subs, feeding the kick and bass through them, but don't send these instruments to the mids/tops. Doing that would allow you to dispense with additional crossovers altogether, just using the LPFs built into the subs and feeding the remainder of the mix full-range to the mids/tops.

I am averse to deliberately dropping frequencies above 120Hz from bass and kick without understanding why it is OK to do so. Can you elaborate?

Rechecking, I see that the subs have 12dB/octave (2 pole) crossover built in. I suppose I should understand if that is Linkwitz-Riley cascaded filter or Butterworth and probably Mackie is the place to find out in the absence of direct acoustic measurements.

In a lecture course I used to give many years ago

What institution?

pcrecord, post: 448556, member: 46460 wrote: Let the mains full range (to give some lows to pianos or other instruments) and make the SUB Aux pre fader, then cut the lows on the bass and bassdrum strip so they don't output low freq to the mains and use a low pass on the AUX Sub.

This might be what the drummer actually implemented. I need to re-check. My lack of experience left me unprepared, in the heat of a gig with zero prior experience in master fader, to check thoroughly. I suspect the aux was all pre-fader.

Does a VCA gang faders without merging signal paths? Controlling the mix was too complicated. If a VCA can fix that then I would use one for the bass, one for the kick, and one for the FOH (thanks for that acronym Donny). That leaves one spare.

Boswell, post: 448557, member: 29034 wrote: Yes, as an experiment. Sorry, I didn't emphasise that.

Experiments are unlikely. I am probably going to have to make all these adjustments incrementally during set-up and teardown at gigs. There is geography, health issues, and time constraint.

Maybe once I have been doing this for awhile and demonstrated more competence then the drummer might be more receptive and let me measure the system to set up the crossover.

CherylJosie, post: 448561, member: 50446 wrote: I am averse to deliberately dropping frequencies above 120Hz from bass and kick without understanding why it is OK to do so. Can you elaborate?

it is no just ok to remove low end on top speaker systems when you have seperate subwoofers, it is recommended.
Here is how I understand it.
Low frequencies are harder to produce for the amp and the speaker. It takes more electricity and energy to project them. When a full range cab is overloaded with low frequencies, it also affects the other frequencies because most speaker protections affect the full Spectrum. If we remove the low end on a speaker, the speaker will be able to project more mids and HF before overloading. So when the lowend isn't there the speaker will be able to play louder. Also, if there is no protection, there is less risks to damage the speakers. Also most full range boxes that are able to produce sub frequencies aren't as good to produce them like dedicated subs. (Their shape and the way they are made internally)
Some will also argue that seperating the sub frequencies will help the speaker a cleaner and more precise sound.
That's why most pro installation uses seperate subs. But this is not true of all systems some boxes are made to be stacked together with full range signals (highend array)

All in all, you would be saving the speakers some stress and strains if you'd remove the low end and it will sound better !
( all good arguments for the owner)

CherylJosie, post: 448563, member: 50446 wrote: Maybe once I have been doing this for awhile and demonstrated more competence then the drummer might be more receptive and let me measure the system to set up the crossover.

Sending him some litterature or video demonstration could help.
If it's a stubburn person, maybe the only way is to make him believe the idea comes from him ! ;)

dvdhawk, post: 448560, member: 36047 wrote: you might create a demand for your sound tech services if you've also got a musical ear.

I might be appropriate to mix for other deaf musicians and bar creatures occasionally but I am not in the market to do this for pay. My top octave faded decades ago.

Your engineering mindset is serving you well in sorting through this, and I'll be surprised if you don't eclipse the PA owner by mid-week.

Thanks. The drummer has been doing this for a while. His practical background dwarfs mine, but I have a theoretical edge.

• If you have a PA system that's balanced and optimized based on the strengths of individual pieces, (i.e. using the HighPass out of the subs to avoid the low-mid overlap) I think you'll get much more predictable results (song to song, set to set, night to night, venue to venue)....Matrix and Aux technology...would actually be a detriment to an admitted novice mixing, at least at first.

Already discovered that complexity the hard way. I have already suggested calibrating the system with a microphone and analyzer using a traditional crossover approach, but so far the drummer has not responded to that suggestion.

• More energy in the sub and low-midrange isn't going to be of any use to you without enough high-mid and horn level to balance it out.

I think they already are experiencing that limitation in some aspects because their standard mix is a little bit muddy, but not sure if it is from lack of mid/treble power capability, or if it is from inexpert EQ shooting at that Reggae tactile. I have not noticed any clipping but with my toasted ears I am the last to know plus I just started on this a couple months ago.

• In your case, I think you can achieve the same net result as you would with the Aux or Matrix approach in a more pure way, by using the HPF on each input - with the added benefit of it being more tunable / adjustable, rather than 'all or none'. (meaning, included or excluded from the sub feed)...

The drummer likes being able to tweak everything from the iPad, plus I think maybe he does actually want to get all the bass he can out of the system.

Now that I understand it, I am up for the challenge of a more complicated setup, if for no other reason than the education (and of course the challenge).

• One way or another, I'd really want to get those top cabinets a couple feet higher.

The mains state explicitly that they cannot be pole-mounted despite having a socket that would mate them to the subs on a pole. I think for liability they have to follow the manufacturer's recommendation so I am not pressing the issue. Fortunately the cabs are always on a stage so far, so they have at least an additional 12" to 36" on the audience.

• All you need to balance the levels of the sub vs. the full-range is an RTA app for your iPad. I use one by "Andrew Smith" in the App Store

Thanks for that. I will check on it. Hopefully it can find a UMIK-1 USB calibration microphone. Even if the calibration data for the mic is not there, the mic is pretty flat by itself.

What genre of music do they play?

Can you can provide any details on number of vocals, and the rest of the instrumentation? (what all is mic'ed up)

Best of luck.

They play cover Reggae, original Reggae, and cover pop adapted to Reggae/Ska.

The drums are mic'd with cardioid, only kick and snare but I bring my mics now so they added a hi-hat mic that they already had a channel allocated for. The kick is one of those longer small diameter things for easy transportation and smaller footprint.

I am trying to get the drummer to mic the cymbals too but so far not pushing too hard because of the clutter and my lack of experience, plus the stage volume is loud enough that the cymbals do not need mic in most of the venues they play. Maybe later, if they bring the stage volume down a little, I will again suggest mic'ing the cymbals.

There are 3 hypercardiod? vocal mics up front for bass lead and rhythm guitarists. These are the type that align horizontally parallel to the floor to aim the null at the monitors.

The lead plays a beautiful pale green hollow Gretsch with a wonderful warm jazz sound but I forgot what amp he uses. I think the bass is fender jazz with two 10" Mesa and running direct out. The rhythm varies but mostly fender telecaster? maybe. Not that conversant with this, never heavily invested in equipment myself. My thing is home theater.

The small-ish lead and rhythm cabs are set flat on the floor and direct out I think (or maybe mic'd cannot remember) but placed behind plexiglass right-angle shields to keep from splashing the audience. I think one is a Fender with a single 12" but not sure. I did not have time to pay attention to these details yet.

I think they rely heavily on the floor monitors. They use at least two of them up front at every gig but since the drummer does not sing there is no monitor in the back as far as I know. No in-ear monitors.

All the guitars are wireless. Everything else is wired except the iPad of course. No racks that I could see, just the usual foot pedals, some small and classic, some larger and complicated.

They have a keyboard player running direct who barely makes a sound, hiding in the background playing rhythm.

They also have a second, partial band rhythm/front man who joins in with his own set, with a female guest vocalist doing some originals beside him too. Mixing it up like that keeps it more interesting but it also means I have to re-adjust the vocal levels and EQ on the fly between sets and songs. Plus they are mixing down the two rhythm guitar amps on stage but they never use both simultaneously so that is manageable. I think they may have run out of channels on the DL1608. Not sure, maybe the drummer just wanted a single fader for the rhythm.

I am hoping to put the vocals through a single submix so I can EQ them as a unit for the proximity effect and adjust their level as a unit. Same/similar for the drums. But I have a long way to go learning the ins and outs of EQ and compression for live sound.

Plus I still have not figured out how the effects channels work, so I just twiddle until they sound about right. NOOB! NOOB! NOOB! ;)

I suspect that additional expenditures are off the table.

So far, I have the following options then, beginning with modified version of the existing setup:

1. Use aux-fed sub pre-fader on bass and kick only, filter the aux and mains separately per input channel to remove sub bass from the mains, and add VCA to the bass, kick, and FOH faders so the subs and full range track each other. Remove the lowpass in graphic from the aux/sub.

2. Use the aux-fed sub post-fader with additional highpass on the mains to match the sub lowpass crossover, and add the VCA to the FOH faders. Add the guitars to the aux sub mix channel for the bottom 40Hz.
3. Use the built-in subwoofer crossover and re-do the mix for a single full range output.
   Of these options, only the first would preserve full bass output capability and allow for strong 'doppler isolation' between subs and mains without the need of any crossover, but it seems like the most complicated to configure and difficult to control.

   The second seems like a simpler compromise that reduces the chance of doppler but it sacrifices some bass output capability from the full range mains.

   The third is simplest and cleanest in practical terms, but it means the system must be carefully calibrated at sound check because I cannot run up on stage and change the faders on the rear of the speakers during a performance plus it again sacrifices some bass output capability from the full range mains.

   Then there is one additional possibility in that matrix crossover doc that I cannot read until I finish the master fader manual, but unlikely to apply since it is probably even more complicated?

   I think I have my answers. Thanks people.

Sorry, a couple follow-up notes:

• If you use the Aux Post-Fader, the kick and bass will 'track' with their FOH sliders.
• Keyboards can go lower than a bass guitar, so you might want to put keys in the sub too.
• I think the mid-show adjustments might be at least partly due to the unpredictable nature of the way they've been doing things. It seems like riding a bucking bronco to me. I think you'll make more people in the audience happy with a mix that's clearer and a couple dB quieter (with well balanced highs and midshipmen's), than wringing a few extra dB out of the muddy low-mid region. Happy audience = more call-backs, bigger audience next time, more fun, and better pay.

Please let us know how your experiments go!!

Yes, thanks for the final notes. I expect I will be back with questions on EQ, compression, and effects after the next gig.

Hello, I mixed my first show in 1993. Since then, up to about 2012, I've mixed hundreds of shows, thousands of bands (thanks partly to open mic nites) in venues ranging from coffeehouses to 500 seat theaters to outdoor events with thousands. Most of my gigs have been club level shows. Your biggest problem is the drummer. I see two options, drum some sense into him or walk away.

That said, I'll add some tech opinions.

First, having aux-fed subs doesn't relieve you of needing a crossover. Bass instruments have a lot of information above the bass range so they need to be in the mains as well as the subs. Having higher frequencies coming from two different kinds of speakers at the same time is not a good thing due to their physical separation and drastically different phase response. Don't use eq for a crossover, use a crossover.

Second, ditch aux-fed subs. It's a brilliant idea but for a beginner running a system like that it's a distraction. Distractions can ruin a show. Instead, aggressively high pass inputs. I assume the DL mixer has variable slope, variable frequency HPF. Set it to 12 or 18dB/octave and sweep up until the tone degrades, then back it down a touch. Also consider running low shelf eq on vocal mics, cutting several dB up to 300-1000Hz, to offset proximity effect. A high pass filter on the whole system can be a good thing, though perhaps those powered subs are doing that internally.

Third, learn how to eq bass and kick. Kick drums often have too much energy around 200Hz. Set up a 1 octave filter with some boost and sweep it around between 100 and 300Hz. The mud should jump out somewhere in that range. Cut it as you see fit. Find the "click" frequency and boost if needed for clarity. I'll usually add a low shelf below the mud to fine tune the bottom of the kick. That could be a boost of cut depending on the situation. With bass I often find too much from 50-100Hz and down, perhaps because it's hard to hear that range when standing next to the amp. Then there's generally a "definition" frequency that you can boost, which could be anywhere between 300Hz and 2kHz. Getting clarity from bass instruments is often enough to get people thinking it's louder than it really is.

Fourth, be aware of the room's contribution. For example, with the subs on the floor they are in "half space", where you get a low frequency boost from boundary effect. Move them to a wall and you've in quarter space for an additional boost. In the corner of the room they are in eighth space for yet another boost. Aim your mains at the audience and away from walls. The back row is a pretty good target for the tweeters.

Fifth, control the stage volume. Do what you can to get people to set their amps to reasonable volume. There are various amp positioning options that can help. The drum/bass/guitar mix should be balanced with the PA off, at least it should be balanced on stage. This will not only make it better for you out front, it will make the monitors work better.

Sixth, mix to the stage volume. Whether or not the band controls their volume you'll still have some kind of stage volume to deal with. When setting up the mix (after line checks, tweaking kick eq etc.) start with the vocals and direct instruments. Make sure they get over the stage noise and then fill in other stuff as needed. If an amp is loud out front don't put it in the mains.

bouldersound, post: 448590, member: 38959 wrote: I see two options, drum some sense into him or walk away.

If anything, I think involving a technically inclined noob to run the sound represents more of a risk than the drummer himself being involved. ;) He got more than he bargained for. We are both doing our best to come up to speed and he seems open-minded, if cautious about making major changes at this point.

Thanks for your other, more technical input. I was vaguely aware of most of it, but having never done it or studied it in detail, I can use all the help I can get.

The last club we performed at hires their own pro sound guy for the gigs, and he re-did all the input EQ (amazingly fast) during the sound check. So we did actually get some pro help, and it cleaned up lots of the 'mud'. I think I learned more about pro sound in 20 minutes of watching him pull curves around with his fingertips than from any reading I did so far. Thanks to you, now I have a written explanation for some of what I observed.

The lack of crossover may be technically wrong, but the equipment is good and the configuration is working OK compared to most of the acts performing at these venues. I guess that is more a condemnation of the competition than praise for us, but everything is relative.

The subs have undefeatable 120Hz 12dB/decade lowpass internally, probably cascaded (Linkwitz-Riley) Butterworth with 6dB of attenuation and 90 degrees of phase at 120Hz. They probably are expecting the other half of that crossover to be a cascaded second-order Butterworth highpass and a phase inversion between mains and subs to keep the amplitude smooth at crossover.

I am not sure if I can exactly implement that cascaded highpass for the mains on Master Fader. I may be limited to a single-stage 12dB/octave Butterworth highpass with 3dB of attenuation instead of 6dB at 120Hz. Maybe I can simulate that integration with SPICE and pick a slightly modified (higher) cutoff frequency to compensate/optimize. This seems an unorthodox approach, but it does avoid me having to make major changes to an already working setup, or invest in an external crossover highpass for the mains.

Another potential consideration is that, lacking any strong reason to 2nd order highpass every signal going to the imminently full-range-capable mains at 120Hz or thereabouts through a crossover, I am reluctant to put the highpass on the output channel feeding the mains. I think I prefer to keep the mains full range for inputs that do not use the subwoofer, and highpass all extraneous low frequencies with the individually tuneable inputs EQ instead.

If the inputs will not let me split the EQ between main and aux, maybe I can run the bass, kick and keys through a submix and use that EQ to implement the highpass for them on the mains. I would need to check that the submix highpass on the mains path does not perturb the aux-fed subwoofer output.

However I do the crossover, actually implementing it and measuring the result is going to be a challenge. The band is on the other side of the SF Bay from me, and I am not, so far, part of their practices.

I am still a warm body to run the faders, and making these structural changes to the system is more than the drummer bargained for. In a way, my taking ownership of this is intruding.

I think he can probably comprehend the issues just fine because he is an intelligent tech professional, but everything is ultimately up to him, including how much effort we put into conforming to the original design intent of crossover.

East Crescent is now running the https://www.qsc.com/live-sound/products/loudspeakers/powered-loudspeakers/kw-series/kw181/ subwoofers with the Mackie mains.

This is the crossover I set:

Here is the vocal subgroup proximity cut EQ:

My youtube playlist for the latest (outdoor) gig:

https://www.youtube.com/playlist?list=PLV7pnC28-tXFRwfuo29mcdtoAUW-y3Pf9

I welcome your comments and suggestions. Thank you.

Hello again, I'm glad to see you've been sticking with it.

The pseudo-crossover looks reasonable. The Frequency Response of the KW181 is spec'ed at 40Hz to 112Hz (within -6dB), so the only thing I'd question is the efficacy of boosting the frequencies below 40Hz so much on the graphic EQ. The sub cabinet cannot produce 20Hz, but may die (and waste a lot of its very limited electricity reserve) trying. Class D amplifiers, like the one built into the QSC, are not usually great at riding out big transients. They are trying to convert wall-current into audio as efficiently as possible to eliminate the need for big heavy transformers. Trying so hard to amplify the octave below the range of the speaker seems like it would waste a lot of energy with no benefit.

That's my opinion anyway. I'll be curious to see what some of the other guys have to say.

My only complaint with the video is the editing, or lack of editing to be more exact. The band sounds quite good through my computer monitors. Outdoors you have to fight the wind and weather, there's nothing you can do about that, but you don't have to fight any acoustical boundaries (walls & ceiling) so it's a good gauge for how good the band can truly sound. The flip-side of that being, not being confined within a box means you need a good bit more PA to fill the same size area.

I agree the pseudo crossover seems ok.
That graphic EQ on the sub aux is nonsense. You are sending signal with frequencies below 100hz. Why would you apply EQ on upper frequencies ??
And that boost up to 20hz is also not a good idea.. most of what the audience feel in the low end happend between 40-70hz. This is were the goodness is. So most of the time we don't need frequencies below 30hz and boosting them only make the subs amp work harder for nothing.

Looking at the video, I would suggest putting the FOH on the floor if possible to gain stage space and the subs will disperse better.

dvdhawk, post: 451524, member: 36047 wrote: Hello again, I'm glad to see you've been sticking with it.

Thanks. I halted the bass lessons though. Too much pain. Maybe later.

the only thing I'd question is the efficacy of boosting the frequencies below 40Hz so much on the graphic EQ... Trying so hard to amplify the octave below the range of the speaker seems like it would waste a lot of energy with no benefit.

Yes, agreed. The house music had lots of low bass in it though and the EQ seemed to help without causing issues. I was more concerned about blowing a breaker than anything. I think we were powered off a single extension cord.

My only complaint with the video is the editing, or lack of editing to be more exact. The band sounds quite good through my computer monitors. Outdoors you have to fight the wind and weather, there's nothing you can do about that, but you don't have to fight any acoustical boundaries (walls & ceiling) so it's a good gauge for how good the band can truly sound. The flip-side of that being, not being confined within a box means you need a good bit more PA to fill the same size area.

The camera is garbage. I only took video so that I could refer back to it and track my improvement. The wind is from the camera mic not the PA.

Eventually I would like to get some wireless gear so I can mic/vid the venue properly. Not sure how to do that. Some of the performances I have mixed have really great moments that would work well for promos, but the recording needs to be good.

pcrecord, post: 451530, member: 46460 wrote: I agree the pseudo crossover seems ok.
That graphic EQ on the sub aux is nonsense. You are sending signal with frequencies below 100hz. Why would you apply EQ on upper frequencies ??

It was not intentional. I stored a 'house curve' of -1dB/octave and recalled it for both the mains and subs before tweaking.

And that boost up to 20hz is also not a good idea.. most of what the audience feel in the low end happend between 40-70hz. This is were the goodness is. So most of the time we don't need frequencies below 30hz and boosting them only make the subs amp work harder for nothing.

Thanks. I was not sure exactly how to handle it, so I figured 5dB was 4x power and if that was going to cause trouble I would probably hear it before it caused any damage. The biggest issue was the power alley.

The gig was not loud at all. Only the kick had a mic on it. We were close up and there was a wall behind the audience reflecting some bass back. If I had to really crank the volume I would have cut it back more.

I had some compression set up for limiting but probably the biggest risk was losing a sub on a mic drop or loose cord. The compression had some attack on it. Would not have stopped it completely.

I should probably have just cut the bottom two bands of the graphic.

Looking at the video, I would suggest putting the FOH on the floor if possible to gain stage space and the subs will disperse better.

The mains would have ended up too low.

The spec says do not pole mount them, they have to sit on a solid surface because they are so heavy and tall.

I discussed it with Charlie while evaluating the power alley. I wanted the subs close together but they were needed as speaker stands.

He wants to replace the Mackies eventually with something smaller that he can pole mount, but the thing is that particular Mackie sounds really, really nice compared to the other (smaller) options...

CherylJosie, post: 451840, member: 50446 wrote: Thanks. I was not sure exactly how to handle it, so I figured 5dB was 4x power and if that was going to cause trouble I would probably hear it before it caused any damage. The biggest issue was the power alley.

Most people don't hear 20 hz givin that the equipment can produce it, that was my point. For exemple, if your Amp can but your speaker can't you can blow up your amp without any warning.
Not only that, most of the electric power would be drained and litle left for the frequencies people can hear.
I saw many people pullout 20hz completly and keeping 25 half way down. (that's what I do)

CherylJosie, post: 451840, member: 50446 wrote: The spec says do not pole mount them, they have to sit on a solid surface because they are so heavy and tall.

You could construct some kind of solid wood crate to put between the subs and the tops if you had the energy and motivation. ;)

I used a 40Hz HPF on my subs. They sounded better and got louder.

dvdhawk, post: 451524, member: 36047 wrote: ** The sub cabinet cannot produce 20Hz, but may die (and waste a lot of its very limited electricity reserve) trying.

I don't doubt you hear something when you boost the 20Hz, but it's going to mostly be the harmonic an octave above you hear coming from the speakers. I agree with bouldersound's approach. I would refer you to the case of die vs. trying referenced above.**

bouldersound, post: 448590, member: 38959 wrote: First, having aux-fed subs doesn't relieve you of needing a crossover. Bass instruments have a lot of information above the bass range so they need to be in the mains as well as the subs. Having higher frequencies coming from two different kinds of speakers at the same time is not a good thing due to their physical separation and drastically different phase response. Don't use eq for a crossover, use a crossover.

I don't think anyone said that those instruments are not going into the subs and main at the same time.
I agree a real crossover is still a great tool by todays digital mixers like the Yam M7CL and LS9 have dedicated sub output that can simplify the soundtech a lot. (by not having to go under the stage to tune the crossovers and hear the results right away from the mixer position)
Also having a dedicated mixer output for subs meens you only send instruments that need subs in it which makes the subs job easier.
Knowing this, I've yet to be convinced one is better than the other.

Of course if your venue gets many people at the mixer and you are not sure of their level of knowledge, you must have a pre-tune crossover to prevent them from screwing up. That's why on many shows I work on, we use both ; crossover and dedicated sub output.

pcrecord, post: 451859, member: 46460 wrote: I don't think anyone said that those instruments are not going into the subs and main at the same time.

I'm not sure it was clear whether or not they were at that point, so I made a general suggestion.

pcrecord, post: 451859, member: 46460 wrote: I agree a real crossover is still a great tool by todays digital mixers like the Yam M7CL and LS9 have dedicated sub output that can simplify the soundtech a lot. (by not having to go under the stage to tune the crossovers and hear the results right away from the mixer position)
Also having a dedicated mixer output for subs meens you only send instruments that need subs in it which makes the subs job easier.
Knowing this, I've yet to be convinced one is better than the other.

Of course if your venue gets many people at the mixer and you are not sure of their level of knowledge, you must have a pre-tune crossover to prevent them from screwing up. That's why on many shows I work on, we use both ; crossover and dedicated sub output.

I don't care whether the crossover is in the mixer or a separate device, but using a graphic eq (which I interpreted to mean a fixed frequency, fixed bandwidth set of filters) is not a good choice. If she was referring to a parametric eq with HPF and LPF filter options and graphic display, then I have no problem. It might just be a difference of terminology. High passing the tops is mandatory.

CherylJosie, post: 448551, member: 50446 wrote: The subs are low-passed with the graphic EQ on the aux.

In my opinion, having fully adjustable HPF on every channel and matched powered speakers makes aux fed subs redundant. Just run the mix into the mains using the built in crossovers and high pass your channels as needed, then use the time and energy you just saved not dealing with aux fed subs to focus on mixing the band. It's not a dissertation for a PhD, it's live music.

bouldersound, post: 451870, member: 38959 wrote: but using a graphic eq (which I interpreted to mean a fixed frequency, fixed bandwidth set of filters) is not a good choice

Very good point !

bouldersound, post: 451870, member: 38959 wrote: In my opinion, having fully adjustable HPF on every channel and matched powered speakers makes aux fed subs redundant. Just run the mix into the mains using the built in crossovers and high pass your channels as needed, then use the time and energy you just saved not dealing with aux fed subs to focus on mixing the band. It's not a dissertation for a PhD, it's live music.

You have to be really quite careful about using parametric EQs or (worse) graphic EQs for speaker crossovers, as they are likely not to have phase continuity through the crossover region. An LPF at the crossover will be have a phase lag at the 3dB point, where an HPF set to the same frequency will have a phase lead, the result being double the phase difference between sub and mid. It's one of the reasons that Linkwitz extended Riley's cascaded Butterworth filter for crossover use (Linkwitz-Riley filter) to maintain phase continuity through the crossover frequency. The L-R crossover uses 24dB/octave filters arranged so that they are 6dB down (not 3dB) at the crossover point.

It's standard practice to use delay to compensate for acoustic and electronic timing mismatches. I'm pretty sure I brought this up earlier in the thread, or in this poster's thread on another forum. But given the geometry of a PA system there can only be one spot where things are actually in phase. so getting too picky is futile.

Steeper slopes do help minimize the fact that areas either side of the crossover will be out of phase, because the relative levels are more different. With digital processing it's theoretically possible to use FIR filters which have no phase effect, but they have other disadvantages (ringing, higher latency).

In my opinion, live sound is about making it "good enough +10%" rather than technically perfect. If you get wrapped up in the technical you lose sight of the artistic and social aspects. It's about people having a good time, and technical perfection isn't required. More than adequate is more than adequate.

Apologies for the delay getting back to this.

I think that the reason I ended up without any HPF in the graphic for the subs is because the frequency overlap in the 20/25Hz bands tweaks higher frequencies somewhat too. I do not think it was harmonic distortion I was hearing, though I cannot swear to that given my distorted hearing etc. The gig was not loud at all and I did not hear any bite out of the subs but I did notice the bottom drop out a little when I cut 20/25Hz.

I mixed another indoor gig for East Crescent:

The camcorder was in a bass null in the rear quarter of the room. The bass was far stronger than the camcorder lets on, and somewhat muddy on this gig. The bass guitarist was not happy with his sound and neither was I, plus the kick sounded flabby, but that was primarily due to me being in charge of mains and monitors mix plus full initial mixer setup for this gig. Charlie's iPad was discharged and I had not done any preliminary setup for this latest gig so I customized his last practice session off the mixer.

After reading your helpful comments today, I added the subwoofer 30Hz HPF so I can independently tweak the LFE cutoff frequency.

The new subwoofer parametric, with 30Hz HPF and 80Hz LPF:

The graphic EQ, with -3dB correction at 80Hz crossover (-1.5dB for one band either side of crossover also) overlaid on the -1dB/decade house curve template i.e. -0.3dB/band (this same template is used on both the subs and top cabs):

The top cabs parametric, with 80Hz LPF and 15KHz HPF (I kill everything above 15KHz because my hearing tops out at 10KHz and I cannot hear issues up there so I would rather just cut it entirely than rely on bleeding ears in the audience to notify me of a problem):

The vocal subgroup proximity cut EQ (I did cut another 2dB or so and it helped with the nasally sound):

I am thinking I might move the crossover down to 70Hz for the next gig too. I am still undecided on that. 70Hz seems a little low, but it would help assure that the guitars have full bandwidth.

The Mackie top cabs and the QSC subs are not compatible regarding built-in crossover. Neither has the HPF. The least expensive option is the board so that is what we are doing at this time.

I think I have this crossover pretty well figured out now, except the delay, and I will work on that once I have the correct mic and PC to measure delay with. Until then I might try experimenting a little by ear.

The dissertation comment is apt. I do overthink these things, at least until I understand them and set up a rule of thumb. Known issue, personal style, unlikely to change any time soon.

This forum has been wonderfully responsive and helpful. Thank you all.