Getting a good bass sound from a PA

Posted: Thu Oct 19, 2006 12:39 am

hI aLL

I would like to know if anyone has any suggestions on geting a good electric bass sound from a PA sytem. Basically the signal chain goes like this:
Bass -> DI Box(not bass DI) -> Desk -> speakers (2x15" and a sub).

What we are finding is that the bass gets lost sometimes during loud songs but is there in the softer songs. Also the bas sound is very WASHY, it's not a tight and powerful sound. Now I realise the setup isnt ideal but it's all the band have. I'm looking to get a cheapish compressor pedal to try to sort out both problems but was wondering if anyone had any other suggestions.

By the way the compressors I'm looking at need to be low cost so i'm gonna have to go with behringer (please dont hurt me!!) or Samson.

Thanks

Posted: Thu Oct 19, 2006 12:59 am

it's di, acting more like amp

http://www.tech21nyc.com/bassdriver.html

Posted: Thu Oct 19, 2006 1:59 am

Hi

Sorry, I dont quite understand your answer. Are you saying that it is the DI BOX's fault.

Also, I love the Tech21 unfortunatly it is too expensive.

What bass and pickups do you have?
What kind of cable and how long is it?
What DI are you using?
What is your console?
What are the model numbers of your speakers?
What processors are you using and where are you crossing over?
Where do you place the subs?
Dual 15s are hardly ever good for linear bass, unless the 15s are crossed over independently, and well below 250Hz, because ALL dual 15s comb filter.

Posted: Thu Oct 19, 2006 7:46 am

To be truthful, getting a "tight, powerful sound" doesn't come cheap. You haven't really given us the details of your speakers and amplification. That is the area of concern to deliver the goods.
What I believe that Groff was saying is that the DI like a Sansamp can deliver the tone of a good bass amp where a lot of DIs fail. That particular model imparts a bit of compression to the tone. as far as getting a "cheap" compressor, I would suggest a BlueMax (it is reasonably clean, and has an active preamp frontend) or, better yet, a FMR RNC. I have also seen a number of live bassists using the Aphex Punch Factory in their rigs. These seem to be popular with the Latin big band players I mix for, and these dudes have the chops! You can find used BlueMax's on e-Bay for under $100.00...is that cheap enough?
Anyway, if your 2x15" cabs are "budget" boxes like the JBL JRX, some Peaveys, Beh$#$%, Samson, etc., you are really taxing them with pushing bass in them. Ditto with cheap subs. And how much/kind of power are you putting to them? Are you bi-amping the system (seperate amps for the mains and subs)? Anyway, enlighten us a bit on the rig...

Posted: Thu Oct 19, 2006 8:12 am

Hi Moonbaby

Thanks for that.

The speakers are JBL'S as well as the sub(which is also a 15"). The desk is a yamaha (dont know model but it is a 21 channel). The power amps are also yamaha (there are 2 500w amps).

I live in South Africa so it is really difficult to get hold of the smaller companies products like FMR.

This setup is for church so the budget is unfortunatly limited. Also, music products in South Africa are quite expensive and that is why the only option for us is the "cheap" option.

I realise that you pay for what you get but we dont really have a choice.

Another question: if we purchase a small 30w bass amp and the Line it out to the PA, would this create a better sound than a DI.

Thanks for the time.

Posted: Thu Oct 19, 2006 9:39 am

Hi, Clinton:
I sympathesize with your situation. I believe that you would be better off with a "real" bass amp rather than trying to push the bass through the PA, but a small 30-watt bass amp will never be heard onstage if it's competing with drums and other instruments up there. You will end up cranking the volume up so much that the tone will be "farty" and unuseable. And, in all likelihood, you will still need the DI box hooked up to the Line Out because most small amps don't have a "real" XLR output, and if you are running a line to the desk and it's longer than, say, 6 meters (20 feet), you run into all sorts of nasty noise problems.
So, you have a bass, but no amp? I'd say put up with your situation for the time being, save up a bit more cash and pop for a more powerful (say, 100 watts with a 15" speaker) dedicated bass amp. You might still have to run it out to the board, but not nearly as "hard", so you can spare the house speakers some pain. And you and the others onstage will be able to hear you clearly enough to keep the rhythm "tight". In addition, the tone controls on such an amp will help you get the sound control you want. Patience, mi amigo, patience.
BTW, we had a president here in the States named Clinton...ever heard of him? Laughing

Posted: Thu Oct 19, 2006 10:43 am

Hey Thanks Moonbaby.

I will try to see if I can get a couple a guys together and put in for a bass amp.

Maybe a Fender Rumble 100 or a Laney - what do u think.

Also I have a question about bEHRINGER BASS AMPS: are their products hated because of the actual bass amp SOUND or is it more because they cant take the wear and tear of a gigging band. If it is more the wear and tear then should I maybe look at them as the amp will never be moved off the church stage.....again what do u think.

Thanks again. Your input is appreciated.
Clint

Yeah I have heard of pres Clinton....Your ex Pres and my ex Pres (Mandela) are currently on the road giving support to the aids fight.

Posted: Thu Oct 19, 2006 2:36 pm

Well, the B%$^$& amps are just...toys, but so are a LOT of amps like those. They are simply cheaply-built gear that does not gig well, and the sound quality, in many cases, leaves much to be desired. Other amps to avoid include the smaller Ashdowns that, like the B$%# are made in China. The Fender Rumble will probably be a good choice. So would most
Ampegs, Hartke's, SWRs, and Peaveys. Peaveys are real big here in churches in the South. I don't care for their audio gear, but they have a good reputation for their guitar and bass amps. Their TKO is a popular model of bass amp. I have no idea as to pricing in your country, but Peavey strives to be the "best bang for the buck" here. Also, while I have no experience with Laney bass amps, I DO know that the reputation of their tube guitar amps here is horrible. Chances are, they are made by the same factory that the Beh%$^4 are made in...Unfortunately, many name brand British amps are now made in China to less stringent quality demands. This includes MARSHALL (some models), VOX, Laney,and Ashdown. Good Luck!

Posted: Thu Oct 19, 2006 7:48 pm

Affordable PA systems are designed to be loud, efficient and fairly bulletproof. The tradeoff is that they can't put out much bass in the deeper regions. At lower levels, things are fine, but the woofer excursion (and/or amplifier) runs out of gas.

One thing to try is putting a filter in the PA signal path to aggressively rolloff the bass frequencies below 50 Hz. If the filter is sharp enough, and properly adjusted, you shouldn't lose too much of the bass you are hearing now, but much less power will be wasted at high levels.

There are many ways to accomplish this kind of filtering without spending too much money, and a decent pro audio dealer can steer you in the right direction. Most garden-variety "equalizers" can't do this job, however, since their filters are not of the proper shape.

Posted: Thu Oct 19, 2006 9:25 pm

anxious wrote:

Affordable PA systems are designed to be loud, efficient and fairly bulletproof. The tradeoff is that they can't put out much bass in the deeper regions. At lower levels, things are fine, but the woofer excursion (and/or amplifier) runs out of gas.

One thing to try is putting a filter in the PA signal path to aggressively rolloff the bass frequencies below 50 Hz. If the filter is sharp enough, and properly adjusted, you shouldn't lose too much of the bass you are hearing now, but much less power will be wasted at high levels.

There are many ways to accomplish this kind of filtering without spending too much money, and a decent pro audio dealer can steer you in the right direction. Most garden-variety "equalizers" can't do this job, however, since their filters are not of the proper shape.

I know many budget systems that are high power and have thunder bass. Too many variables in that one for me.

Having a friend from the country of the OP, I know that AC power quality can be iffy. If the power is iffy, the power amp performance will be off as well.

Posted: Fri Oct 20, 2006 2:34 am

Sheet, fair enough. But, don't you think a filter to cut out signals below the response of the speakers would help in that case, too?

After all, pumping 20 or 30 Hz into a typical PA system is just going to tax the woofers, the power line, etc. The acoustical response will be almost nill for a vented system, and the speaker impedance will be very low, thus drawing extra current. 50 Hz is pretty low stuff for a basic live sound situation. For example, the JBL JRX125 is a decent dual 15" speaker, and is spec'd down to 45 Hz, (-3 dB).

Anyway, I know it is a complex issue, with many variables.

Posted: Fri Oct 20, 2006 8:36 am

I personally find the JRX to be a poor representation of the JBL brand name. In my speaker repair business, I have found them to certainly NOT be "bullet-proof". Inspecting the innards reveals stamped frame woofers and a non-serviceable horn driver.
Anyway, there are other issues here. This bass player is trying to get his tone from the PA, not a stage amp. This not only taxes the house system (despite a subwoofer), but whatever stage monitors he has (if any) so that the band can "click". No bass on stage, no "click", and running bass through the typical monitors these rigs tend to have is gonna sound "mushy" and hinder the clarity of the vocal mix. I believe that Mr. Clinton needs to generate an appropriate level of bass onstage via an amp designed for that purpose. When the band can groove, so will the congregation! And the PA will be cleaner for it...

Posted: Fri Oct 20, 2006 1:03 pm

Moonbaby (is that legal?),

Thanks for the very articulate post. While I won't comment on the JBL's in particular, after a few reads, I think you nailed the issue: get the bass guitar out of the PA mix.

So where do you repair speakers, if you don't mind the question?

Posted: Fri Oct 20, 2006 2:09 pm

I have partial ownership in a repair/live sound business in NE Florida, north of Daytona Beach. I don't do too much of the speaker stuff, but handle the tube amp and live sound side of things. But I SEE what these companies are doing to put out cheap boxes, and am appalled. The JRX boxes are clearly using a stamped-frame Eminence woofer, plus the HF drivers are Chinese and have no way to replace the diaphragm! Now, I happen to think that Eminence makes a great product, and they keep getting better, but the models that JBL is using are not nearly as robust as the models that, say, Yamaha, is using in their Club Series. So I must be getting old and bitter. Sorry about the rant....Have a great weekend, guys!

Posted: Fri Oct 20, 2006 3:30 pm

Oh my! JRX is JUNK! They were not intended to be used as FOH mains, They were the poor man's background music speaker. That's your problem right there.

I guarantee the next problem is your bass. If you do not hahve the right wood, construction and pickups, you will never get real bass, no matter what you are playing through.

The following problem would be your fingers. The player = tone. I can put Billy Sheehan on a Fender P Bass and get that fart-like, almost fretless tone. Hand that same bass to "what's his name
in Tool, and hear it growl.

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