Pro-Audio Power Amps for Home Audio?

[bastek]

Take a look inside a pro amp and you'll feel better. Nothing to be ashamed of.

And as for fan noise:

 

[rebos123]

Sorry to ask a dumb question, but what are the pros/cons for using a Crown or Crest power amp, etc. with a home audio-style preamp?

Why aren't they more common? What are the issues - sound quality? Noise?

Please advise.

Thanks very much.

Regards,
LouLoomis

Well, one issue I see right off the bat is if you have a "home-audio" style preamp it probably has RCA jacks (unbalanced) for output. Most pro-amp have balanced input jacks. Not a major problem, but you will either have to buy adapters or make some cables to go from RCA to balanced connectors.

 

[Elliot Thompson]

I have a couple of Crown CT-200 amps.
They are the 100 WPC and have no fans.
They sound great.
Just because they are "pro amps" doesn't mean they will blow speakers.



Rob

Unless you've literally taken out the fans in those Com-tech 200 amplifiers, they offer a fan. I am very familiar with Crown amps.

When most people are looking to wards a professional amplifier for home usage, they generally seek an amplifier that exceeds home amplifier wattage ratings. 250 watts per channel home amplifiers (Soundcraftsmen, Hafler, Carver, etc) were very common in the 70's & 80's.

So, unless someone is looking for a more industrial look, there is no benefit buying a professional amplifier rated @ 100 watts versus a home amplifier rated @ 100 watts.

Speakers can blow up faster based on too much power if the user has no idea when enough is enough. Unlike a small amplifier that will distort when overdriven (Which common sense should tell the person to turn it down) a larger amplifier can be far away from clipping. This in turn, eliminates any sign that the speaker is becoming overloaded.

There are two things that will destroy a speaker. Too much power from a mechanical (excursion) or thermal (heating up the voice coil) standpoint. If the speaker gets too much power thermally the voice coil will burn up. If the speaker gets too much power mechanically, the driver’s components (Cone or Spider) will mechanically fail. You can hear when a driver is failing mechanically (popping sound) however thermally (which many drivers tend to fail) will give you no sign except for white smoke. By the time that occurs, the damage is done.

Best Regards,

 

[rifftrax]

Older Yamaha pro amps are highly recommended as well, i.e. the full-sized models such as P2200, PC2002, etc.

Totally with you on this one.

I had a Yamaha P2250 that just whomped on the competition that I had (all types of integrateds, powered mixers, home theater offerings, etc). Sounded fantastic. One of the things I regret most in this hobby is selling that guy.

I've got a halfer PRO1200 which I think sounds very lovely and crisp and another mosfet power amp which I still need to test and also owned a BGW Systems D250 which rocked and TBH I've never met a decent pro audio amp that I didn't like tremendously...(all of them have been sufficiently heatsinked to run minus a fan, which was also great).

The nice things about pro audio amps is that they don't muddy up the design with tons of DSP, tone controls, filters, routing, video circuits, other stuff which I just don't normally need at all or can handle being kept on a different unit. All that extra circuitry and boards cause channel crosstalk and raise the noise-level and etc., etc.

 

[dnewma04]

So, unless someone is looking for a more industrial look, there is no benefit buying a professional amplifier rated @ 100 watts versus a home amplifier rated @ 100 watts.

There is sometimes a price benefit that would need to be considered, as well.

Speakers can blow up faster based on too much power if the user has no idea when enough is enough. Unlike a small amplifier that will distort when overdriven (Which common sense should tell the person to turn it down) a larger amplifier can be far away from clipping. This in turn, eliminates any sign that the speaker is becoming overloaded.

There are two things that will destroy a speaker. Too much power from a mechanical (excursion) or thermal (heating up the voice coil) standpoint. If the speaker gets too much power thermally the voice coil will burn up. If the speaker gets too much power mechanically, the driver’s components (Cone or Spider) will mechanically fail. You can hear when a driver is failing mechanically (popping sound) however thermally (which many drivers tend to fail) will give you no sign except for white smoke. By the time that occurs, the damage is done.

Best Regards,

Excellent. Almost exactly how I would have written that. I figure that if a user is ignorant enough to try to make a 30w amp act like a 100w amp, he is just as likely to make the 300w amp act like a 500w amp.

 

[Endspec]

I run a Soundcrafstman RA 5502 in the main room, it has no fans and sound real good but I need better speakers for it. The rat shack T 100's are a little on the small size for it. If I crank on it the speakers will bottom out real easy so it stays low on the volume till new speakers find there way in the house.

 

[Robisme]

Unless you've literally taken out the fans in those Com-tech 200 amplifiers, they offer a fan. I am very familiar with Crown amps.

I did not remove the fans. The fans were an option with the CT-200.

It is not the same as a consumer amp. Not your typical one anyways.

It alerts you when distortion exceeds .05%.
It can be bridged for, like, 305 watts mono.
Run 70 volt line.
They are built to take more abuse than a consumer amp.


Rob

 

[Elliot Thompson]

Here is what a damaged voice coil resembles when it gets too much power.

Usually a driver that encounters an amplifier that is clipped severely will have only a chared spot (a line) on the voice coil. This one however, is the end result of having an amplifier too powerful in which, the user felt the speaker can handle all the power providing, the amplifier does not clip.

Best Regards,

 

[Elliot Thompson]

I did not remove the fans. The fans were an option with the CT-200.

It is not the same as a consumer amp. Not your typical one anyways.

It alerts you when distortion exceeds .05%.
It can be bridged for, like, 305 watts mono.
Run 70 volt line.
They are built to take more abuse than a consumer amp.


Rob

As I said, I am very familiar with Crown amps. If you purchased the amplifier to take advantage of the 70-volt line (driving multiple speakers using transformers) I can see the benefit.

There are many home power amplifiers that offer clip indicators (in Crown's case IOC) that will detect distortion. Soundcraftsmen's "True Clip" triggers @ 0.05% THD and Nikko's Peak triggers at 0.01% THD.

If you think you can drive those amplifiers in an abusive manner without the aid of fans, the ODEP will say otherwise. :thmbsp:

Best Regards,

 

[70salesguy]

Got to know your limitations!

Of course, the biggest disadvantage of using a "Pro" amp is you won't have that "Boutique Brand" amp for all your status conscious friends to fawn over.




There can be no doubt that a high-powered amplifier can damage speakers, and in a variety of ways. But I do believe, as mentioned before, that far more speakers have been damaged due to "clipping" from insufficient power.

Unless you are trying to use your basic home speaker for a block party and push it hard for hours on end, I don't really see most people that have any "audio sense" about them creating this type of damage on a very frequent basis. While it is true that very few speakers, except for those designed and built to very stringent standards could withstand exceptionally high volume levels for extended periods, most people with any common sense at all should know when they are abusing their speakers.

If a person has this type of concern about damage to voice coils, they should definitely avoid amplifiers with large amounts of clean power such as a Crown amplifier. As Dirty Harry Callahan said, A man's got to know his limitations!

And for our lady members, a woman needs to know as well!

 

[Robisme]

If you think you can drive those amplifiers in an abusive manner without the aid of fans, the ODEP will say otherwise. :thmbsp:

Best Regards,

I bet I never run them past 60 or 70 watts.

I meant abuse of moving them around.

I have two. One powers L-100's and the other HPM-100's. In one system.

As far as purchasing them, I did not. They were free.

I would rather run these for parties than some of my consumer gear that I have collected.:yes:

I didn't say there are NO consumer amps with the features of the Crowns, just typical amps.

I am sure you know more about Crown amp than me, as I only have had these two. But, they are great sounding and seem to be very reliable.

Rob

 

[mulester7]

.....Crown K2, I currently employ three....one on a sub, and two on low separates 15 inch subwoofers in sealed boxes covering the range of 120hz down to 80....a Crown K2's rated Damping Factor is 3000, 10-400hz....gives subs more defined oscillations.....when you bridge a K2, the damping factor is cut in half to 1500....but, 1500, 10-400hz, still has great control over the voice coil for clarity....SVS advised a K1 with their B-4+ mini-barns, but ya' can't get those mini-barns any more .....

.....long story short, two Crown K2s came into my life, and whipped my vintage McIntosh amps, that's for sure, using the same C-26 pre-amp....they were wonderful the whole time I used them for two fronts and two rears in 4-corner....then came the newer technology Mac amp sections along with a newer technology McIntosh pre-amp, and the K2s went to where they are primarily designed to be, imo, producing low end that is clean and defined, "very" clean and defined.....

 

[tensleep]

I am using a QSC CX1202v 600 wpc amplifier to drive a pair of Klipsch KP301B loudspeakers rated at 400 watts continuous. I doubt I ever drive this rig more than 50 watts, maybe 100 watts - it just gets too loud! The QSC is fused with a 25 amp fast blow fuse. The Klipsch are also fused, I forget the size. I will eventually biamp. You might consider fusing your speakers if you are truly concerned about overdriving them. There are also compressor/limiter circuits as well.

I also have a TOA 900 series 60 wpc mono amplifier driving an Infinity BU120 subwoofer for my home theater. The plate amp in the Infinity was no good and the TOA was free.

I cannot hear the QSC cooling fan since I have it in a cabinet with plenty of air circulation. The TOA does not have a fan. I frequently check the amplifiers and they barely get warm, even at full volume.

The drawbacks, as already mentioned, are different connectors for inputs and outputs as compared to home audio gear. I have also found that a good preamp is necessary to properly control and switch between various program sources.

 

[cmb3366]

My first stereo was built around a Crown SL-2 and a Crown PS-200, with a McIntosh 2100 thrown in occasionally for biamp duty. Crown makes rugged gear for sure, and depending on what you are looking for, it's decent gear, but after having gone down the tube/SET path, and hearing the difference that amplification can make in a system, I would not go back to the Crown gear in a hifi setting for any reason.

 

[guest109]

The K series of Crown sounds great to me, I use it for my main speakers. Love the extra horsepower it provides...there's no substitute for horsepower.

 

[Jeff M]

"I am using a QSC CX1202v 600 wpc amplifier to drive a pair of Klipsch KP301B loudspeakers rated at 400 watts continuous"

Yikes, does that combo take the paint off the wall? I borrowed a set from a dealer, of the 1400 QSC's, to bi-amp my Gammas and lets just say that I retuned them quickly. :sigh:

 

[tensleep]

"I am using a QSC CX1202v 600 wpc amplifier to drive a pair of Klipsch KP301B loudspeakers rated at 400 watts continuous"

Yikes, does that combo take the paint off the wall? I borrowed a set from a dealer, of the 1400 QSC's, to bi-amp my Gammas and lets just say that I retuned them quickly. :sigh:

When asked what I could expect from this setup, a member at the Klipsch forum stated that I could expect to sterilize all of the cats in the neighborhood - he was right! I can't even get close to running this full open - at 400 watts, the spl is rated at 125 dbl.

BTW, when I first read your post, it looked like you biamped your Gramma's speakers. That much power would certainly blow up her bloomers.

 

[bowtie427ss]

Let me ask a question, and please, let's keep the highly debatable answers objective and not start any flame wars at differing opinions.

What defines an amplifier as "home" or "pro"?

 

[Jon_Logan]

There's nothing legally that defines a Pro amp. I used to work for a sound reinforcement company that had SAE P-2200's and a Dynaco 400 used for pro work. Pro means you get paid. Many "pro" labled amps are worse than these "Hi-Fi" amps. You can get into semantics and say "well these have fans, handles and balanced input jacks". This would make them geared for sale in the pro market, but there are no restrictions on what people use for pro sound, or hi-fi. Somebody who chooses to use SoundDesign for a pro application will probably have an unpleasant experience, while people using Crown (or QSC, or Crest, etc, etc) are more likely to not have an amp failure with high average output into low impedance load uses. The Hafler's are a good example of this crossover mentality. Most of their "Pro" amps are their hi-fi amps with XLR's and level controls fitted. .....just because that's what Pro use is used to having.

 

[tensleep]

From my experience, Jon Logan is hitting the mark. Without getting into the technicalities, which I don't feel qualified to parse, I would suggest that each type of amplifier is designed to be more convenient for the end user in its intended environment at certain price points. Things like typical connectors and controls will be different for differing environments. Some features in a sound reenforcement environment would be absolutely unnecessary in a home environment and vice versa.

There are other design differences, to be sure, and there are very good reasons to understand what they are before repurposing equipment that was specifically designed to perform at an optimum level under certain conditions. For instance, power requirements for large "pro" amplifiers can exceed the safe capacity of a home electrical circuit, especially older homes. Now, I realize that there are also some "home" amplifiers that require dedicated circuits as well, but I think the point is valid. Often, pro amps are designed to be controlled by a separate mixing board or some such device. Many home amplifiers are integrated with a preamp and/or a tuner for convenience, cost savings, space and asthetics. Again, there is no hard and fast boundary here, either.

I don't know how familiar you are with audio gear. If you are just getting into it, do yourself a favor and go to a Best Buy and look around at their audio offerings. Then, go into a Guitar Center's sound room and look around. Look at the different cables and interconnects, etc. If you are lucky enough to have a good hifi store, then go in there and you will see where the line blurs.