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Any pro amps with 200-500 w/ch and > 115db s/n ratio (at rated power)?

post #1 of 39
Thread Starter 
I'm looking for something reasonably priced at around $200 per channel - i.e. $400 for a 2 channel amp to power some 102 db/w/m speakers.

Emotiva and Rotel both make 2,3 & 5 channel amps with +4dbu inputs that fit the bill, but I was interested in other options. Most of the pro amps seem to quote a s/n of 100db which is going to make for a lot of hiss with seven channels.
post #2 of 39
Behringer ep4000
post #3 of 39
Thread Starter 
Quote:
Originally Posted by Scott Simonian View Post

Behringer ep4000

I can't find s/n specs for the ep's anywhere. I know they are a clone of the QSC RMX amps which have a s/n ratio spec of 100db (no output specified).
post #4 of 39
Check out the Peavey IPR1600, 300x2 into 8ohms, you can pick it up at a guitar center for 299. Should be right up your alley.

The guys over at Gearslutz really like them.
post #5 of 39
Thread Starter 
Quote:
Originally Posted by Stumbo View Post

Check out the Peavey IPR1600, 300x2 into 8ohms, you can pick it up at a guitar center for 299. Should be right up your alley.

The guys over at Gearslutz really like them.

I can't find any specs on the signal to noise ratio on those amps. Inexpensive amps are great for subs and/or 'normal' speakers, but the high efficiency stuff really needs quite amps.

I have a crown d-45 that is very quite, but only 25 watts and I'm clipping it and high volumes.
post #6 of 39
Cerwin vega Cv1800 is 102db
Crown xls1500 is 103db
Either of those work? This has been on my mind but I can't find the time to finish my subs much less move on to building mains.
post #7 of 39
the new crown comtech is 110.

http://www.crownaudio.com/media/wysiwyg/CT_Dowloads/ComTech_Datasheet.pdf

otherwise, ati is way up there (120db or so) but so is the price.

the whole "at rated power" thing confuses the whole issue. what "rated power"?

a 5000 watt amp with 110db and a 100 watt amp with 100db, the 100 watt amp has about 7db less noise.
post #8 of 39
You don't need 115dB SNR, you just need to set it up correctly. When I had my fully front loaded horn system (circa 105dB efficient from 300Hz up, a couple less below that) I used generic Rotel amps which are nothing special noise wise and had no noise at the speaker with no signal. They were integrateds with the processor that ran the preamp faulty, so I bought them and only used the power stage; 100W units, but don't recall the model number. I was running active, but you can get a passive system silent at the LP with large directly heated triodes if you build it well.

Manufacturers measure it differently so make sure you are comparing like with like, and that it's broadband.
post #9 of 39
Quote:
Originally Posted by steve71 View Post

I can't find s/n specs for the ep's anywhere. I know they are a clone of the QSC RMX amps which have a s/n ratio spec of 100db (no output specified).

I use an RMX2450 to drive my 100db sensitive side surrounds. They are dead silent. No hiss with my ear an inch away.
post #10 of 39
Thread Starter 
Quote:
Originally Posted by JohnDean View Post

Cerwin vega Cv1800 is 102db
Crown xls1500 is 103db
Either of those work? This has been on my mind but I can't find the time to finish my subs much less move on to building mains.

Probably too noisy @ 103db.

Quote:
Originally Posted by LTD02 View Post

the new crown comtech is 110.

http://www.crownaudio.com/media/wysiwyg/CT_Dowloads/ComTech_Datasheet.pdf

otherwise, ati is way up there (120db or so) but so is the price.

the whole "at rated power" thing confuses the whole issue. what "rated power"?

a 5000 watt amp with 110db and a 100 watt amp with 100db, the 100 watt amp has about 7db less noise.

Crowns look interesting, but don't do 4 ohms. Might not be an issue with these speaker though. Those ATI's look perfect, except for the price. The used ones on ebay look to be in good condition, not beat up like most of the pro amps.

By "at rated power" I mean just that. 200-500 watts is only about 4db difference, or am I not understanding your question? smile.gif


Quote:
Originally Posted by A9X-308 View Post

You don't need 115dB SNR, you just need to set it up correctly. When I had my fully front loaded horn system (circa 105dB efficient from 300Hz up, a couple less below that) I used generic Rotel amps which are nothing special noise wise and had no noise at the speaker with no signal. They were integrateds with the processor that ran the preamp faulty, so I bought them and only used the power stage; 100W units, but don't recall the model number. I was running active, but you can get a passive system silent at the LP with large directly heated triodes if you build it well.

Manufacturers measure it differently so make sure you are comparing like with like, and that it's broadband.

I've been using horns in an active setup for a few years, but this time round I have a big space to work with so I want the same speakers all the way around (might even go with 9 or 11 channels). Many amps have passed though that system (115db/w/m from 300hz up) and the only ones that had acceptable noise levels were the Crown d-45's.

Other than adjusting the gain controls I'm not sure what you mean by set up correctly? My building is DEAD quite (for the most part ). The Crown D-45's at 105 s/n and 25 watts can't be heard unless your ear is right up to the horn. So I figure a 250watt amp will give me an extra 10 db of gain, so 115db s/n ratio should have the same level of hiss as the d-45, but with an extra 10db of gain on tap... or did I mess that up?

The Emotiva and Rotel amps are both 200 watts and 115 db s/n (no gain controls though). Emo is $200 per channel and the Rotel (used) is about the same.

I have a crown XLS 402d (can't find any s/n specs) and it has WAY too much hiss when the gain controls all the way up - It's 300 watts.
post #11 of 39
Thread Starter 
Quote:
Originally Posted by bobdoggy View Post

I use an RMX2450 to drive my 100db sensitive side surrounds. They are dead silent. No hiss with my ear an inch away.

Good to know, I'll check them out, thanks!

EDIT: Where do you have the gain controls set?
post #12 of 39
The crown is 2 ohm stable. I'm using the 1500 now at that load level and I'm happy
post #13 of 39
Thread Starter 
Quote:
Originally Posted by rr14 View Post

The crown is 2 ohm stable. I'm using the 1500 now at that load level and I'm happy

The XLS 402d (which I have is very noisy), but the COMtech amps that LTD mentioned have 110db s/n, but put out the same power at 8 and 4 ohms.

Those ATI's are looking good with 120db s/n and they are a true balanced design.
post #14 of 39
qsc plx2 series is -106db s/n and not too bad on price.

i don't really know anything about s/n in amplifiers and i am having a real difficulty trying to draw meaningful comparisons because there is weighted, unweighted, 1w, full power, etc. and it is often not specified what conditions produce the rated s/n.

i would definitely like to know more about this one and will be following along.
post #15 of 39
A9X is correct, the key is to setup your gain structure properly.

I also wouldn't put too much stock into spec sheet S/N numbers. I'd guess the reputable pro amp companies like QSC and Crown are very conservative with their S/N ratings. My experience is that consumer companies vary in how they measure and aren't afraid to embellish (although I'm not saying ATI, Rotel or Emotiva are dishonest...my experience with each is positive).

Ultimately, with your gain structure properly setup and quality properly operating amplifiers you shouldn't have any noise issues with 102db sensitive speakers.
post #16 of 39
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

qsc plx2 series is -106db s/n and not too bad on price.

i don't really know anything about s/n in amplifiers and i am having a real difficulty trying to draw meaningful comparisons because there is weighted, unweighted, 1w, full power, etc. and it is often not specified what conditions produce the rated s/n.

i would definitely like to know more about this one and will be following along.

I'm simply extrapolating from the Crown D-45 @ 25 watts and 105db s/n. Stands to reason that a 250 watt amp would give me an extra 10db of sound and and extra 10db of noise. So a 250 watt amp with 115db s/n should have the same level of hiss as 25 watt amp with a 105db s/n.

Quote:
Originally Posted by coctostan View Post

A9X is correct, the key is to setup your gain structure properly.

I also wouldn't put too much stock into spec sheet S/N numbers. I'd guess the reputable pro amp companies like QSC and Crown are very conservative with their S/N ratings. My experience is that consumer companies vary in how they measure and aren't afraid to embellish (although I'm not saying ATI, Rotel or Emotiva are dishonest...my experience with each is positive).

Ultimately, with your gain structure properly setup and quality properly operating amplifiers you shouldn't have any noise issues with 102db sensitive speakers.

I agree 100%, but I'm kind of over messing with the gain controls every time I want to turn it up. If I can use amps that have > ~115db s/n ratio then I should be able to run the gain wide open all the time, right?. Of course this assumes a low noise pre/pro. [EDIT: I shouldn't say wide open, but rather I would be setting the gain where it needs to be in order to clip the amp with the pre/pro at close to max gain]

I was just testing out another amp I had laying around - Crown CP660 which is IIRC 105db s/n and has an output of around 100 watts with only 2ch driven. I had to connect the ground to the chassis of the DVD player to get rid of the ground hum. But it was still there a little bit in one channel. The D-45 had no hum even without connecting the GND to the DVD chassis. Maybe the issue with the XLS402d is improper grounding??
Edited by steve71 - 3/23/13 at 4:04pm
post #17 of 39
Thread Starter 
Opps... I spaced on the fact that I'm using -10 dbu DVD player into a +4 dbu amp and that is why I have to peg the gain controls. I'm so used to my active setup (dbx x-over) that takes -10 and outputs +4.

This poor gain structure isn't going to help with back ground hiss tongue.gif
post #18 of 39
Quote:
Originally Posted by steve71 View Post

Good to know, I'll check them out, thanks!

EDIT: Where do you have the gain controls set?

Set at 12 o'clock, but full gain results are the same.
post #19 of 39
just out of curiousity, what happens if you plug the XLS402d into the wall and hook up your speakers, but nothing else and turn the gain controls all the way up?
post #20 of 39
Quote:
Originally Posted by steve71 View Post

I can't find s/n specs for the ep's anywhere. I know they are a clone of the QSC RMX amps which have a s/n ratio spec of 100db (no output specified).

http://www.avsforum.com/t/855865/measuring-amplifiers/30#post_10753603

I guess it's not high enough for you though. : /
post #21 of 39
Thread Starter 
Quote:
Originally Posted by bobdoggy View Post

Set at 12 o'clock, but full gain results are the same.

Thanks, that is good to know!

Quote:
Originally Posted by LTD02 View Post

just out of curiousity, what happens if you plug the XLS402d into the wall and hook up your speakers, but nothing else and turn the gain controls all the way up?

I will give it try this week - the speakers are in an unheated outbuilding at the moment and temps here are in the single digits lol. I've had those 402d's for ages and I've tried just about everything to get rid of the noise, but I'll check again.
Quote:
Originally Posted by Scott Simonian View Post

http://www.avsforum.com/t/855865/measuring-amplifiers/30#post_10753603

I guess it's not high enough for you though. : /

Thanks for the link. Since I've realized my mistake with the gain structure, I should now have 14db less noise just by setting things up correctly. So then as others have pointed out, I don't need 115db s/n. 100 should be fine.
post #22 of 39
My Crown XLS1500 is silent now. And it does 4 ohms I dunno why you said it doesnt. I'm about to buy another one to power my new subs.
post #23 of 39
Thread Starter 
Quote:
Originally Posted by tential View Post

My Crown XLS1500 is silent now. And it does 4 ohms I dunno why you said it doesnt. I'm about to buy another one to power my new subs.

I was referring to the crown comtech amps that LTD suggested, not the XLS1500. smile.gif

FWIW the Crown XLS 402d was great when I compared it with a Bryston 7B ST amp. But that comparison was on 88db/w/m speakers where the noise wasn't an issue.
post #24 of 39
I am thinking about trying one of the Peavy IPR-1600's for my mains. Probably will order it tomorrow.
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post #25 of 39
CD quality is -96db SNR (16bit)

So as soon as you play a CD, your noise in the signal increases to 96 regardless.
Note: If you play an MP3 it gets even worse.

It would take a (properly recorded) 24bit signal (such as blu-ray HD audio) to not increase the noise level beyond -96db.

Take a look at the SNR of this $50,000 Hi-Fi amp. It is -90db at 1 watt. If that amp can't do it, then it basically can't be done, and an AVR from best-buy certainly can't either, the AVR it probably -70 eek.gif

http://www.stereophile.com/content/mbl-reference-9011-monoblock-amplifier-measurements

Most amps reach their lowest noise between 10 to 100watts, above or below that it starts looking like a happy face. It's just the way it is.
post #26 of 39
Quote:
Originally Posted by BassThatHz 
Take a look at the SNR of this $50,000 Hi-Fi amp. It is -90db at 1 watt. If that amp can't do it, then it basically can't be done, and an AVR from best-buy certainly can't either, the AVR it probably -70 eek.gif

In the esoteric audio world, price is hardly a guarantee of quality. In fact, the higher the price the closer I'd check actual performance.

Many amps have published snr of mid 90's at 1 watt. Is it that you don't believe them?
post #27 of 39
Quote:
Originally Posted by AV Science Sales 5 View Post

I am thinking about trying one of the Peavy IPR-1600's for my mains. Probably will order it tomorrow.

The adult* version of the IPR-1600, the Crest Pro Lite 2.0, is now available, and not much more expensive than the IPR-1600. (The Crest has a slightly better feature set too: a dedicated bridge-mode output, and a bit more capacitance.) So you might want to look at that instead.

I recently picked one up and gave it a spin on an Aurasound NS12-794-4A in a 65L closed box. It will eventually drive two of the four subs in my sister's basement theater (an NHT B-20 will drive the other two.). Worked just fine, every bit as good as my much more expensive (but also much more dense, as it fits 8 500W/4Ω channels into a 2RU package) multisub amp, an ElectroVoice CPS-8.5.

On the subject matter, S/N, the Crest is clearly not as quiet as my Sherwood Newcastle A-965 on my amp-noise test (Eminence APT tweeter on one of their horns, plugged in), but then again I've not found anything near the price of the A-965 that's as low in self-noise as it is. (Similarly low-noise amps are things like Brystons, Anthem Statements, and McIntoshes.) I'd recommend one for the OP, but they're out of production, and 3dBW less powerful than desired. (Though with 102dB/W/m speakers, 20dBW of power with 1.5dB headroom per channel should be more than sufficient domestic audio use....)

*black rather than cheap-looking silver, no blue lasershow on the circuit board, heavier metal chassis. I think the fan might be better, too. The Pro Lite 2.0, at least, is a lot quieter than the IPR-3000 I briefly had.
Edited by DS-21 - 3/24/13 at 10:00pm
post #28 of 39
Quote:
Originally Posted by AV Science Sales 5 View Post

I am thinking about trying one of the Peavy IPR-1600's for my mains. Probably will order it tomorrow.

I have 3 of them at the moment, one for my sub, one for my mains, and one for my whole house audio. I couldn't be happier, especially for the money.
post #29 of 39
Quote:
Originally Posted by DS-21 View Post

The adult* version of the IPR-1600, the Crest Pro Lite 2.0, is now available, and not much more expensive than the IPR-1600. (The Crest has a slightly better feature set too: a dedicated bridge-mode output, and a bit more capacitance.) So you might want to look at that instead.

I recently picked one up and gave it a spin on an Aurasound NS12-794-4A in a 65L closed box. It will eventually drive two of the four subs in my sister's basement theater (an NHT B-20 will drive the other two.). Worked just fine, every bit as good as my much more expensive (but also much more dense, as it fits 8 500W/4Ω channels into a 2RU package) multisub amp, an ElectroVoice CPS-8.5.

On the subject matter, S/N, the Crest is clearly not as quiet as my Sherwood Newcastle A-965 on my amp-noise test (Eminence APT tweeter on one of their horns, plugged in), but then again I've not found anything near the price of the A-965 that's as low in self-noise as it is. (Similarly low-noise amps are things like Brystons, Anthem Statements, and McIntoshes.) I'd recommend one for the OP, but they're out of production, and 3dBW less powerful than desired. (Though with 102dB/W/m speakers, 20dBW of power with 1.5dB headroom per channel should be more than sufficient domestic audio use....)

*black rather than cheap-looking silver, no blue lasershow on the circuit board, heavier metal chassis. I think the fan might be better, too. The Pro Lite 2.0, at least, is a lot quieter than the IPR-3000 I briefly had.

I will take a look at it. I don't have to worry about looks or noise. Amps are hidden in a mechanical area, below the theater. Also, not for sub duty, but for mains.
Edited by AV Science Sales 5 - 3/25/13 at 8:19am
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post #30 of 39
Just to add another option to the mix.

http://www.yamahaproaudio.com/global/en/products/poweramps/ps_series/specifications.jsp

I use the p2500s and p7000s with much success. Gains set to half with 2 Samson S-converts in the chain and I get no noise whatsoever.
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