Neumann KH 120 vs Dynaudio BM6A

Discussion in 'Monitoring' started by audiokid, Jun 23, 2011.

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  1. Davedog

    Davedog Distinguished Member

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    I still have my KH-120's. I like them. A good reference to the mids. They are not nearly loud enough and for a larger room they wouldn't be a number one certainly nowhere close to a mid-field. I have gone back to a passive set-up. Killer crossovers and components and a great amp specially prepared by Sundholm Engineering. Later this year I will step up with a "better" pair of the same monitor I'm using now with much better parts and some design tweaks. I still like the powered sets . There's a lot to be said about systems that are designed to be part of the whole. What I really find with an excellent passive system is the clarity is better and they become 'more listenable' for longer periods of time. Since I'm not in the business of cooking someone elses tracking, I don't have a lot of need for surgery. That doesn't mean that these passives I have aren't surgical. They are, and being able to bounce from the Neumanns and back makes for a pretty good fact checker. I moved my little Genelcs with the sub into the living room and I'm really surprised how good these sound as home stereo speakers. I have a pair of Dahlquists in the rear position for my 5.1 in the living room, but these will be changed out to another pair of the Genelecs sometime in the future. Checking a mix is very telling in the living room.
     
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  2. dvdhawk

    dvdhawk Well-Known Member

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    Hey Dave, could you clarify something for me please? Are those passive crossovers with a stereo amp, or are you using an active crossover and going stereo bi-amp / stereo tri-amp / 3-way + sub etc.?

    When I get to that point - I still own 2 stellar active crossovers, and have considered going stereo tri-amp + sub IF (BIG IF) I were ever to think about soffit mounting 'thrill them/kill them with volume' speakers. I have a couple decent pairs of powered near-fields (JBL LSR4328 & Adam A7x), but they certainly have volume limitations. So I'd like to hear more about your set-up for a longer throw, if you can give just a bit more info about the 'crossover and components' I'd appreciate it. (Oh, and BTW thought about you when I saw an A-T ATM25 for $150)
     
  3. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    @dvdhawk sorry to butt in here, you've made me realize I know next to nada about crossovers. What I wanted to comment on tho, is your soffit mounting idea. I know you said BIG IF. I have only mixed on one pair of soffit mounted mains, urie 813c's w the Jbl drivers, and coaxial tweeters (I think that's how you describe it). Even w some real modest Hafler amps, not even real high wattage, and just one amp per speaker, they go way louder than I can stand. While I feel the bass response isn't quite modern, and I'd add 2-4 18"subs to the system, there has never been a nearfield I've used that has had that kind of like "spread" I don't mean loud I mean like big/full. Albeit the coaxial tweeters are kinda harsh and crossovers I'm sure come into play, as well possibly using an exacto knife to cut the protective screen off the tweeter, which is an old trick w those I guess.

    When you close your eye it actually seems like the performance is happening in front, and around you. It's like that image you get from near fields, just large.

    Not to get way off on a tangent, but I was just thinking that maybe a set of bigs, might get ya where you want to be, but maybe a bit cheaper overall than near/midfield + subs.

    If I remember correctly my boss paid like 3k for the pair, used from someone in Delaware, and had to replace a driver, in all reality for a commercial situation like that, all the drivers, and probably some other components, should have been replaced as well, but you know how pocket intensive studio construction is.

    Now, the room was designed, with those already in the hole back in the 70's so, they may sound a little flatter at that studio than elsewhere, but I've had a great, enjoyable time mixing on those, and cross reffing the ns-10s. The mixes translate better than any other room I work in.

    Again, it's the sheer size of the image that impresses me, rather than the loud volume, and they don't have to be loud at all, to sound big. By far the most fun monitors to mix on, I've ever used. It's changed my perspective in a way that can't be undone. The Meyer near fields, and quested mid fields, are quite nice as well, but just aren't as fun.

    The way I describe it is like mixing foh, but with more accuracy, and less beer farts. Well, sometimes...

    Anyway, just thought I'd mention it. I'll be lurking around while y'all are talking crossovers.
     
  4. Davedog

    Davedog Distinguished Member

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    Hmmm... Its a stereo amp. A Parasound HCA 1000A. Its had a bit of a boost to the power supply, its entire in/out section has been converted to industrial so it has the appropriate xlr and in keeping with the incredible hi-fi beast that these are it has gold contacts and some 'other' stuff under the hood. My monitors are Sundholm 6.5's. I think there is still information about these though probably not a lot. These are a set of the first run of them. Later versions had a much better crossover network and the tweeters had a waveguide surround. They are a two-way. They are very accurate and honest while still being listenable. I can mix for hours with no fatigue and all the while looking for the defects in the recordings. I think the KH 120 tonal structure is similar to these only 'less' of it......know what I mean. There is no sub. The next pair will be with subs but I dount I'll use them until I build the new room. IF I build the new room. My desk set-up and orientation doesn't allow for a set of subs. The difference in the nex set and the ones I now have is night and day all across the board. The sound similar except the newer versions are just that much clearer.

    Back in the day I worked in a studio that was a JBL design soffitt mounted, tri-amped system. I think the speaks were 435-somethings. They had a small radial horn with a cheese cutter and 2 woofers and a mid speaker. The guy ran them with a D60 on the horns, a D150 on the mids and a DC300 on the lows. The crossover was something he built. Passive with lots and lots of control. Probably a filter system of some kind...transformers for sure.....ANYWAY...it was superb and one of the reasons I wanted a studio. I've also done a little work in a Westlake bi-amps with passive horns set-up and I lived under a set of Urie 809's for a long long time with a Crown on them.

    So I think to really tune your room and balance your speakers especially in a soffitt mount system, active bi/tri-amp is a great thing.

    Thats a good price these days for an ATM25. Awfully great mics.....did I repeat myself with that???!!!
     
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  5. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Do you recall if those were mono amps, or stereo? Ie, did the d60 power just one speakers horn, or both speakers. I'm moving into passive speakers next pair, particularly qsc theater speakers, and crown digital cinema amps, are the place holders. Just trying to get a handle on on it, since I'm mostly experienced w active speakers.
     
  6. Davedog

    Davedog Distinguished Member

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    Three amps two sets of speaks. If you add it up its not a lot of wattage. Its a whole lot of efficiency. They were loud enough to be a Marshall in the room with you if needed.
     
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  7. dvdhawk

    dvdhawk Well-Known Member

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    Kyle, the Crown D series amps would all be stereo, but 2-channels might be a better way to think of it. Assigning them left/right is up to you. In Dave's example, yes one channel of the D60 powered the left horn, the other half of the D60 powered the right horn - and so on.

    An active electronic crossover, comes in 2-way / 3-way / or 4-way etc. and filters which part of the spectrum goes to which amp / speaker. You can adjust the frequency range of each section (sub / lo-mid / hi-mid / highs), and independently adjust the volume of each section. Then you can use the appropriate low-wattage amp for the tweeters, and work your way up to a big bruiser for the lows/subs. Between picking the right amps, and the level settings on the crossover it makes balancing otherwise mis-matched speaker components a lot easier. Virtually all of the powered near-fields use 2-channel amps and take full advantage of active crossovers to fine tune them. So, each powered nearfield is a self-contained mono 2-way. And if you add an active sub, it's already got an active low-pass filter so it doesn't waste its energy trying to do anything above 120Hz.

    The alternative is a passive crossover network that uses capacitors, coil inductors, and big ceramic resistors, that work together to attenuate everything above the set frequency. The tweeter will get destroyed if it tries to do a bass frequency, and it requires a small fraction of the power you want for the woofer, so the passive crossover takes care of both of those issues (frequency dividing and attenuation). The problem you sometimes see with passive speakers, is they sound good at a low-modest volume, but change tonally at higher volumes. Sometimes that's just the interplay between the crossover components changing as a signal gets stronger. And whoever thought of using a lightbulb as a fuse in passive PA speaker is a genius, it's a brilliant way to dissipate excess energy.
     
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  8. Davedog

    Davedog Distinguished Member

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    Heh heh....We used to mount them right behind the grill cloth when you had the pop-off grill so you could see them from the FOH position. More driving of the PA meant the lamp glowed brighter! I loved it when they were really bright. It meant everything was cooking with gas.
     
  9. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Awesome man, that makes a lot of sense. If I understand it, the passive crossover can only attenuate, where the active have the ability to boost?
     
  10. dvdhawk

    dvdhawk Well-Known Member

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    The frequency dividing of an active system would be a similar concept to a multi-band compressor, low-pass, a high-pass, and a crossover point or two in between. Theoretically you could boost a band a couple dB, but the object of the game with active crossovers is efficiency - letting each speaker do what it was designed to do best without a bunch if wasted energy. Remember, Frequency and amplitude are two separate issues. Your subs and lo-mids need lots of power to move the air to generate those big sound waves, with big speaker boxes, long excursion 18" and 15" drivers. The high-mid horns and super tweeters are making relatively short wavelengths and need proportionally less power to do their job. All other things being equal in an active system, the smaller the driver ( which might range from 21" subs down to 3/4" super tweeters) the less power it requires to perform its job, AND the less power it can tolerate before burns out the windings. Back in the days of subs and lo-mids like Earthquakes, W's, Scoops, Perkins, A7 Voice of the Theater, FRCs, etc., you wanted 500w - 750w going to each cabinet loaded with the appropriate 15" or 18" JBL, Gauss, E-V, or C-V driver. Meanwhile you only needed a tenth of that to make your JBL 2440/2441 2" horn drivers to scream loud enough to keep pace.

    One of the shortcomings of a typical passive PA system, is that the balance between the horn and the woofer isn't usually the same at all volumes. Now with any passive speaker for example, you may have 500w of program coming in. The woofer may be able to take 500w all day long. The tweeter has 2 problems with that. 1) It cannot possibly get enough travel out of its tiny voicecoil to generate a frequency below 1kHz, but without a crossover it will absolutely die trying. 2) Even if it's running through a crossover, and only sending freqs above 1kHz to the tweeter as it should, 500w is probably 10x its maximum wattage (excessive amplitude). Again it would die trying, so the passive crossover uses large high-power ceramic resistors to attenuate the signal above 1kHz down to a wattage the tweeter can handle. How do the resistors do that? By converting that excess wattage into heat, which is a serious waste of energy, but a necessary evil in a passive system. Remember, man can neither create, nor destroy energy. We can only change it from one form to another. No surprise, the quality and power-handlng specs of these components is a major contributor to the sound quality of a passive cabinet. How well those resistors do their job, will determine how balanced the sound is at higher volume.

    Bottom Line: In a 2-way system the horn / tweeter operates at a fraction of the wattage required for the woofer / sub. So you have to either use resistors to attenuate the highs (passive components), OR you can divide the frequencies first (with active electronics), and apply a low- wattage amp dedicated just to the horns, plus a high-wattage amp for the woofer. Repeat as necessary for 3-way, 4-way and beyond.
     
  11. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Thanks for your patience! I started recording/gigging in '99, and I'm still learning about the tools we use everyday. I've used drive racks a fair amount of different places, this to me seems like it's an active crossover based on how I seeing this. Is thAt correct? From what I remember there were 3-4 crossover points and a hpf/lpf.

    You mentioned that passive speakers can exhibit changes in tone at different volumes more, than a similar active speaker. Is this the case even in the "high end" stuff, say McIntosh, (the only high end amp company I know)? Is the idea to match "flat amp to flat speaker" or kinda match them in way say, where the amps might be scooped, and the speakers have the opposite curve?

    I guess what I'm getting at is. Can you avoid this tonal change of passive speaker at any (realistic-ish) price point? Is this were a proficient crossover system comes into play? Are there different rules of thumb for power amp head room, based on speaker size. Like it makes sense to me to have 1,000w amp runnin a 3-500 w woofer, for good transient response, and cool operating temperature, but it seems 100w amp, a on 25-30 watt tweeter would be "more than enough". The numbers are just for illustration.

    I spent an extremely long time doing figures for this home theater project, figuring in actual, electrical service headroom, and matching the amps to the speakers. Fortunately crown, and Jbl, had great data published, so it was more a process of matching things up. My current line of thinking is that things in general like to run in the 30-70% range of their max ratings. It seems to be a trend with electronics in general. Is is somewhat 'proper'.?

    One of the biggest eye openers to me was that a 15A breaker could and almost should, pop around 12a. The electrician did the final numbers, and I haven't been down to inspect it yet.
     
  12. dvdhawk

    dvdhawk Well-Known Member

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    A dbx Driverack is a modern-day example of an active crossover, that's right. In addition to being a stereo 3-way crossover, it would add a digital graphic EQ tied to their RTA analyzer, mic and pink noise generator. Compressor/ Limiter function, feedback suppression for your Mains. Pretty impressive for a 1U box. Again, (old man voice) 'back in MY day', it was an 6 rack spaces of Klark-Teknik DN360 EQ, Rane RTA, dbx 160x, at the board FOH + the 2U for a mono Crown MX4 crossover in the amp racks on stage to accomplish the same functions in glorious mono. Add several more if you wanted to run in stereo.

    I think it's safe to say, higher quality speaker manufacturers use better crossover components, and really labor over every tiny detail to make sure their speakers will stand up to the scrutiny of the audiophile market. (You cannot imagine a group that's more...... I'm going with, 'fussy'). Meanwhile, low-end manufacturers are more inclined to have a bin full of crossover boards that handle x-number of watts and cross at x-Hz and say, "that's close enough". Some really cheap speakers use nothing more than a single non-polar capacitor inline with the + wire to the tweeter, which acts as the band-pass, but offers zero attenuation.

    And to your point of specs and headroom, always take them with a huge grain of salt. Reputable companies like Crown and JBL as you've mentioned, have nothing to hide and provide pretty good detail about the specs and HOW they were derived. There are industry standards. Low-range gear knows in order to compete, they have to post the all-important wattage rating as high as possible - because that is how most consumers make their judgement at point of purchase. So some less reputable manufacturers hype, exaggerate, or outright lie to post a high number of watts, by neglecting ALL of the standard testing criteria. Failing to mention things like noise, distortion, or how long it performed at that level. When JBL tells you their speaker will take 3200-watts of 'Program' and 1600-watts 'Continuous' , it's because they have Torture Tested the design with 100 hours of continous Pink Noise. And then, they'll go into detail about the specifications of the Pink Noise. While your low-ball company will post competitive spec numbers, but conveniently omit the fact that their amp or speaker will implode after a fraction of a second, and/or sound like you're mixing through a Tube Screamer pedal. You could put 3000-watts through a 3" speaker from an old clock radio (for a few milliseconds before the glowing-hot voicecoil shot across the room and caught the drapes on fire).

    As you have noticed, running any sound equipment maxed out, and right on the threshold of its breaking point isn't usually a recipe for fidelity. I personally am from the school of thought that believes more people have blown up good speakers with the square waves associated with under-powering them, than having amps several times the rating of the speaker. It's one thing to have the voicecoil overshoot it's normal excursion for the duration of a single transient, and complete catastrophic failure when it travels out hard and holds there long enough to weather the duration of the (clipping) square waves. Again, excess energy, the voicecoil can't move any farther, so that energy has to go somewhere. And again it becomes heat, and heat kills.

    I'd like to hear what @Davedog has to say about that 15-amp breaker. I don't understand why it would break at 12. It will momentarily hold far beyond 15, otherwise you couldn't power up one good amplifier, due to the amount of inrush current involved in simply turning on a big amplifier.

    Which brings me back to manufacturer specs. If a company tells you their amplifier produces 4000 watts, and it has a normal 15-amp Edison power cable - start looking for the fine print in the specs. In the US, let's assume you have a typical residential 15-amp receptacle. Chances are there is more than one receptacle sharing a 20-amp circuit breaker. In any case, in our 120V system a 20-amp breaker's theoretical limit is 2400 watts (and the IEC to 15-amp Edison cable, 1800 watts). But giving it the benefit of the doubt, how is that 4000 watt amp making more power than it's taking in? It isn't, it defies the laws of physics. Read the fine print on the spec sheet. Even the reputable amp manufacturers are guilty of this, but at least they provide the fine print - where the shady amp companies conveniently omit it.
     
  13. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    My laughter echoed loudly in an otherwise empty home.


    Multit quote on my iPad is screwy, so I'm gonna just respond, I'm sure y'all get the gist.

    Very interesting point about underpowering speakers being more dangerous and overpowering. This line of thinking is making more sense to me in the past few years as I explore electronics. One of the reasons I deliberated so long about an anemic psu for an off the shelf computer.

    Breakers-

    I might have been just flat out wrong, so hopefully Davedog will chime in when he has a sec. The electrician said (last year when we were planning) that the breakers will handle momentary overshoots without popping, that it's a continuous draw, or prolonged peak, that will heat the wires up enough to pop the breaker. From what I could decipher from www, the rule of thumb when figuring ampre draw was add up the gears ampre draw from their rated specs, and whatever number you arrive at, shouldn't exceed the 75-80% max rating of the breaker.

    My guess was for huge l.f.e for example, where the amp might actually be pushing itself momemtarily, that you want the headroom for. But again, just my interpretation. I think this would contribute to less total distortions, and full sound, that didn't thin when peaked. Again, assuming the drivers are within their normal operating range.

    If I remember correctly, and I can check if it'll help, crown even rated the ampere draw at 30% 50% and peak. While also defining both recommend, and min-required breaker size.


    I've had one or three of those trip-lite isolation xformers, for my audio gear, as a precaution for ground issues, over here at home. I don't have ground problems usually, and fwiw, I probably gonna add a couple dedicated circuits, because I may be getting a non-sound isolated extra room to house my gear, till I move in a couple years. Anyway, my point was, that even the ISO xformer which is there 15a model, is rated for 12a in the spec. Which frankly confused the confusion I already had on the topic....

    I'm just being lazy not posting links, but I'll be glad to if it would help in any way. My tablet is great, but I do miss the drag and drop of a computer, otherwise, I'd used nothing beside the tablet for things.
     
  14. dvdhawk

    dvdhawk Well-Known Member

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    It seemed to me you were saying before that the 15A breaker would blow at 12A, but that makes a lot more sense when you put it this way. I can absolutely see the reason for making sure the constant load on the breaker would fall comfortably below the max. by 10%-20%. There's going to be a certain safety margin in the watt/ampere number printed on each device anyway. They have to figure its power consumption at worst-case-scenario (running flat out).

    Crown, for example, does include the spec for power consumption while at idle, 1/8th rated output, 1/3rd rated output, and full-output.

    Doing the math on the milliwatts / watts / amperes that your gear consumes will also come into play calculating your HVAC requirements in an airtight room.
     
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  15. Davedog

    Davedog Distinguished Member

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    Ahh circuit breakers. The rating of your typical residential and small frame commercial breakers is based on a set of curves that represent time, heat, magnetic flux and current. A typical 15A non-adjustable thermo-magnetic breaker will operate at its full rated ampere load continuously for a defined amount of time. Could be years, depending on the TYPE of current and all of the variables within it's content. There's a lot of theory here to explore but I have to go supervise a kitchen remodel this morning so I'm only going to comment briefly.

    Anyway....The 12A rating your electrician made comment on is in fact the legal loading of a circuit supplied by a thermo-magnetic non-adjustable breaker. This is mostly for circuit design and for code requirements. The 15A breaker in question will NOT trip @ 12amps and if it does it is defective. If you look on your breaker's frame casing, there will be a rating of the A.I.C. rating of the breaker. There are a lot of factors that contribute to this rating. It is basically how much current the device will withstand with a direct short applied to the load side of the device. This is generally, in residential and most small commercial settings, 10,000 A. A lot of this is determined by how far away a facility is from the transformer supplying the electrical service and is also referred to as Fault-current.

    So to quickly summarize.....the INRUSH of a load on a breaker is handled by the thermo part of the breaker. An inrush of many many amperes above the rating on the handle of a circuit breaker may not have enough heat in a specific amount of time to trip. Again....the RATING of a breaker is more about the design of a circuit and its uses. You are allowed a percentage of the breakers capacity when determining what size of breaker to use and this is based on type of load, ambient temperature, wire size, and code requirements.

    A motor load for example may in fact be 400% of the breakers rating but under particular conditions will be perfect for the requirements.
     
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  16. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    This was a life saver for me. I specd the breakers, so be able to handle continuos usage at peak power, w the 10-20% wiggle room. We didn't want blown breakers, and would rather the amplifiers own protection circuits initiate, and shut down, before a breaker blew. I'm sure the electricician 'streamlined' this to some extent.

    Ditto for the amps acoustic power relative to the speakers. We specd the amps out to be able to run the speakers at their peak ratings, continuously, within their optimal/efficient operating range. Obviously we wouldn't do this, the house would probably fall down. Basically I got amps that run continuously, at the speakers peak power.

    Lol thank goodness, theirs a little machine room, where an a/c and/or air exchange unit will be placed. Having all that amplification in the veiwing room would be a challenge acoustically, and thermally.
     
  17. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Thanks @Davedog. I'm gonna re read this a few times, my head is more mushy than usual. But I think I've at the concept. If there's and links, or info, about the theories behind things, I'd certainly read through it, so I can communicate more clearly.

    I kinda bombarded the thread here, which was about monitors, so I'll shut up about breakers Ect on this thread.

    Thanks to both of you guys. I think many many sound engineers could benefit from some edification in this area, I consider it part of gain staging.
     
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    The New AT5047 Premier Studio Microphone Purity Transformed

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