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Pro-Audio Power Amps for Home Audio?

L

louloomis

Active Member
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
 
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Elliot Thompson said:
The main issue is the fan noise for some. Another reason is a higher chance of destroying their home speakers.
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Fan noise was a game breaker for me when I had a high power QSC pro amp. The fans were on at all times, and quite loud for a quiet environment. I did like the extended power range though.
 
Interesting. Some of them don't have fans, though. But I can understand fear of destroying home speakers (considering the wattage of some of these units).

However, and I know that this is a subjective issue, so the primary concerns isn't of how these kind of power amps affects tone?

Thanks again.
LouLoomis
 
louloomis said:
Interesting. Some of them don't have fans, though. But I can understand fear of destroying home speakers (considering the wattage of some of these units).

However, and I know that this is a subjective issue, so the primary concerns isn't of how these kind of power amps affects tone?

Thanks again.
LouLoomis
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You mentioned Crown & Crest. Which one of those offers no fan? The only one that comes to mind is Crown K Series and, that was discontinued over 5 years ago...

Sound is very subjective. What makes matters worse are those who feel their opinions are law and become highly upset when someone ask for graphs or documentations to prove their facts. :thmbsp:

A power amplifier is designed to deliver a flat response across a frequency across a 20 - 20 kHz bandwidth. Anything that affects the tone stems before the power amplifier. All the amplifier does is increase the levels of whatever signal is fed through it.

Speakers will react differently on an amplifier. However, their response (impedance, excursion, etc) is known to fluctuate while reproducing music. This is one of the reasons why you will never see a loudspeaker’s frequency response flat from 20 – 20 kHz.

Instead of asking what someone thinks, it would be best to just buy a used pro amplifier on ebay and try it out your self on your speakers. For as you said, sound is subjective. :yes:

Best Regards,
 
You don't need a pro amp to cook speakers, but do agree on the fan noise. I had a Dynaco 400 and fan noise was more than it should have been. As for cooking power, I was running two bridged Carver A760x's in my system at 1200W+ rms/channel awhile back. Sounded great, with fabulous dynamic range, but speaker repair got expensive. Had to back it down a bit. And yes, there is such thing, as to much power.
 
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.

100_2648.jpg


Rob
 
I use Crown XTI 2000's to power the bass on my speakers. They have fans but rarely ever come on......only briefly after really cranking. So, fan noise is not an issue with these amps.
 
I'd venture to say that more speakers have been blown by 30 watt receivers than 200 watt amps. When the 30 watt receiver clips hard it dumps lots of high frequency, high power, crap into the tweeters. A 200 watt amp won't clip as easily. A lot of people either can't hear clipping or it doesn't bother them enough to turn it down.

I used to run a set of Realistic Minimus 7's (4", 2 way) on a Phase Linear 700B (350 W/C ) and never hurt them. The same amp took out a JBL 4311B woofer one day when I dropped the tonearm.
 
If you try using the search feature, you will find thread after thread concerning the use of pro amps in home systems with more answers than you will ever get here...

There is no problem using pro amps.. to me, the fan makes no difference, unless it is an unusually loud fan, which most aren't... .you turn on music, you can't hear fans..

The Crown D series also don't have fans. They are older amps thtat do sound great. I used a D150 on my horns at the moment..

Like someone said, best you can do is find an amp you like (specs, looks, what ever) and give it a try and see if they make you happy.
 
d3imlay said:
I'd venture to say that more speakers have been blown by 30 watt receivers than 200 watt amps. When the 30 watt receiver clips hard it dumps lots of high frequency, high power, crap into the tweeters. A 200 watt amp won't clip as easily. A lot of people either can't hear clipping or it doesn't bother them enough to turn it down.
.
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:thmbsp: Truer words were never spoken.
A higher Voltage (higher power into a load) will preserve the fidelity of the wave, keeping those hard edged clipping waveforms from your tweeters. Although tweeters and midranges are usually the components that suffer from clipped waveforms the most, woofers can suffer too. It's much harder to measure as the waveform isn't sinusoidal any longer, there's much more energy under the curve. So a 20W (8 ohms sinusoidal) may have much more power output when clipped.

Bigger is better, except for fan noise.
 
I use a slightly modified Citronic PPX450...it's vintage-ish, made in the late 80's. A real bargain compared to a similarly built hi-fi power amp as it has all the hi-fi quality components - Alps pots, toroidal trafo, metal film resistors and dual mono circuit boards.

Fan noise isn't an issue if you put the amp on some rubber blocks to isolate it. I hardly notice the noise in normal listening.

For those with concerns about electrical noise in the speakers, I can have the pre at full whack (risky, I know...) with only the slightest hint of hiss from the tweeters. Only the cheapo pro amps suffer from noise in my experience.
 
besides more power under the curve, the other nasty problem from clipping is mechanical. the speaker cone/coil is moving at a high rate of speed, then all of a sudden at clipping it goes essentially to a full stop. the g force associated with that can be huge.
 
Older Yamaha pro amps are highly recommended as well, i.e. the full-sized models such as P2200, PC2002, etc.

One thing I would say is that the amp can indeed affect the sound quality it passes through, and do take power ratings with a grain of salt. Music is much harder on the amp than the sine waves used to test. The power supply, whether traditional or switching, must be robust enough to not be stressed by what you're asking the amp to do, otherwise it will not act like an "ideal" amp and you will be able to hear the difference. Lesser amps of a given power will start to sound congested in the mids/highs and soft in the bass sooner than better amps of that same power (or sometimes even less power).
 
similost said:
If you try using the search feature, you will find thread after thread concerning the use of pro amps in home systems with more answers than you will ever get here...


The Crown D series also don't have fans. They are older amps thtat do sound great. I used a D150 on my horns at the moment..

Like someone said, best you can do is find an amp you like (specs, looks, what ever) and give it a try and see if they make you happy.
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I'm using a pair of bridged Amcron/Crown D75's, thus approx 90 watts per channel with very high damping factor, and they sound better on the Mach 2's than anything else I've used.
 
louloomis said:
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
Click to expand...

One of the main issues is that most consumers simply do not think about using pro audio equipment, so they shop the home consumer markets for systems. Some also may feel that using pro audio hardware would seem too odd for them. Others may have misconceptions about them in general.

Cooling fans generally only get noticeable when they need to push high amounts of CFM across components to keep the amp from reaching a thermal overload condition. This really depends on the design of the amp combined with its power output.

My fans come on after the amps have been pushed steadily and heavily for several minutes.

Here's my rack of Crest V1500's. They all run bridged and supply either eight JBL SR-4725A's or four SR-4732A's, as well as two SR-4719A's subs. The SR-4725A's are powered so that each pair is running in parallel at 4 ohms and driven by a bridged V1500. The horns are powered from other Crest amps (V1100's, V900, etc). Runs in stereo except for the subs.

These are part of the Audio/Mastering Studio, not the living quarters. I run the system about once a month to keep the caps properly formed (with plenty of hearing protection). I also recently connected up my pre-teen son's Wii so he can listen to Guitar Hero games when he plays them while mom's not home. (At reasonable volume levels) He describes it as being "Totally Wicked, Dad!!!". Which, as I understand, is a good thing. :)


Crest-V1500x6.jpg



. . Falcon
 
cdfac said:
Music is much harder on the amp than the sine waves used to test. The power supply, whether traditional or switching, must be robust enough to not be stressed by what you're asking the amp to do, otherwise it will not act like an "ideal" amp and you will be able to hear the difference. Lesser amps of a given power will start to sound congested in the mids/highs and soft in the bass sooner than better amps of that same power (or sometimes even less power).
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I don't disagree that lesser amps are, well, lesser. However, music is not harder on an amp in terms of load/output than sine waves.

Music, in general, has a much higher peak to average ratio than does sine wave.

Meaning, if you have a 500WPC amp, and push it to the verge of clipping with music, the amp is producing probably 60 - 70W average output. Whereas, if you have that same amp and push it to the verge of clipping with a sine wave, the average output is much, much higher. This is why the old 1/3 continuous power preconditioning test shut down many good amps (including some of McIntosh's best) whereas with music at ear-bleed levels, they hardly broke a sweat.
 
And another pro amp fan here...these run my home theater, and have all been modified with different fans. Even in a silent (relatively speaking) room, you cannot hear the fan noise from more than a foot or two away.

All my HT speakers are 8 ohms, so the stack below is capable of delivering 3,800 watts to the speakers (not including self-powered sub).

picture.php
 
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