4 Amps To Compare

[dadalr]

Anyone can help me in comparing/recommending any of these amps; which one would be the best (pros/cons) for 7.1 ht setup.

1) Anthem Statement P5
2) Cinenova Grande 7ch
3) PS Audio GCA-500
4) Theta Dreadnaught II

 

[highfihoney]

need more info.

Anyone can help me in comparing/recommending any of these amps; which one would be the best (pros/cons) for 7.1 ht setup.

1) Anthem Statement P5
2) Cinenova Grande 7ch
3) PS Audio GCA-500
4) Theta Dreadnaught II

before anybody can give you decent advice more info is needed about what other gear the amp will be matched with,listening/watching levels,room size,speaker system/subwoofer.

 

[Josuah]

Well, I don't really think all of that information is necessary. An amplifier has one job to do and you can measure whether or not it does it well. And I imagine you've already narrowed down your watt requirements. Unfortunately, the only one of those amplifiers that I'm aware of measurements for is the Anthem.

http://www.hometheaterhifi.com/volume_11_4/anthem-statement-p5-amplifier-12-2004.html

Based on being able to place a fork over the contacts, I'd say the Anthem can drive any load with sufficient current. Which means it should be able to handle any speaker regardless of its impedance plot. It also has extremely low measured THD and IMD, which measured better than their specification ratings. There's a slight roll-off in the frequency response, but I'm sure it's negligible in comparison to most others.

Secrets (see above link) also has reviews for different versions of the Theta and PS Audio. You might consider those comparable. But in my opinion, PS Audio's approach to technology is a little strange, and the Anthem seems to be the best value.

 

[dadalr]

re:

before anybody can give you decent advice more info is needed about what other gear the amp will be matched with,listening/watching levels,room size,speaker system/subwoofer.

7 speakers in -wall Bay Audio; room size 18 x 25; subs 2 velodyne dd15; no other equipment yet - just finished building the HT;

 

[Josuah]

Well, all of the BayAudio in-wall speakers should only be run with up to 100W per channel. Their 400 series only 32W. And all listed at 8ohms nominal. I'd say all of those amplifiers you listed are overkill. Get an Outlaw Audio 7125.

And make sure you are running at 75dB average volume at your seating position, during movies. That'll hit 95dB for peaks (105dB for the subs) which is going to be just about the maximum those speakers will do.

 

[dadalr]

re:

Well, all of the BayAudio in-wall speakers should only be run with up to 100W per channel. Their 400 series only 32W. And all listed at 8ohms nominal. I'd say all of those amplifiers you listed are overkill. Get an Outlaw Audio 7125.

And make sure you are running at 75dB average volume at your seating position, during movies. That'll hit 95dB for peaks (105dB for the subs) which is going to be just about the maximum those speakers will do.

well, when you're matching a power amp to a speaker, a good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's power rating. So in this case shouldn't be the amp rated at least 200w/ch? Using an amp with some extra "headroom" will help assure that only clean, undistorted power gets to my speakers - correct? The exact opposite would damage the speakers (clipping of an amp).

 

[mtrycrafts]

well, when you're matching a power amp to a speaker, a good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's power rating. So in this case shouldn't be the amp rated at least 200w/ch? Using an amp with some extra "headroom" will help assure that only clean, undistorted power gets to my speakers - correct? The exact opposite would damage the speakers (clipping of an amp).

Are you planning on driving your speakers to their limits?
How sensitive are they? Maybe you need different speakers?
No, I didn't hear about that rule. From the rating of 100 watts, even a good receiver will handle your speakers, unless they are at the limits constantly in which case, perhaps other speakers may be in order?

 

[Josuah]

That's a good point. Good thing you're thinking more clearly than I am today.

 

[dadalr]

Are you planning on driving your speakers to their limits?
How sensitive are they? Maybe you need different speakers?
No, I didn't hear about that rule. From the rating of 100 watts, even a good receiver will handle your speakers, unless they are at the limits constantly in which case, perhaps other speakers may be in order?

88db sensitivity 109db max at 100w; too late for different speakers - back boxes are already built in the wall; I don't think I will be driving them to the max (JTi series)

http://www.bayaudio.com/jminwall.html

 

[Josuah]

Hm. After thinking about it a bit more, I wonder if it's really worth it to double your watts. It'd cost about $1000 more, at least, and it only gives you a 3dB safety net before you'd drive the amp to clipping. (Although perhaps there is circuitry already in place within the amp to prevent that from happening.) And it's not like the speaker's power rating of 100W has anything to do with making sure you don't drive your amp past 200W.

Seems like a safer and more cost efficient approach would be to make sure you can't raise the volume too high. The Emotiva DMC-1 has such a feature. Perhaps the processor you purchase would also. Or, just don't do it by having that feature in your brain.

 

[ragged]

well, when you're matching a power amp to a speaker, a good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's power rating. So in this case shouldn't be the amp rated at least 200w/ch? Using an amp with some extra "headroom" will help assure that only clean, undistorted power gets to my speakers - correct? The exact opposite would damage the speakers (clipping of an amp).

So if my speaker says 150 watts, my amp should be pushing 300 watts to it?

 

[PENG]

Most speakers specify a "suitable range" or something like that,e.g.

Paradigm Studio 20:
Suitable Amplifier Power Range 15 – 150 watts

Polkaudio RTi6:
Recommended Amplifier Power 20-125 w/channel

B&W 805S:
Power Handling 50W - 120W into 8 ohms on unclipped programme

I would say it is reasonable to use amps that double the speaker's "minimum" recommended number but not necessary to double their "maximum" numbers unless you tend to listen really loud, but then you may have trouble dealing with the speaker's own high distortion level when they are pushed to their limit even if you use power amps.

 

[zumbo]

7 speakers in -wall Bay Audio; room size 18 x 25; subs 2 velodyne dd15; no other equipment yet - just finished building the HT;

From this statement, I see there is no receiver/pre-pro yet. I also believe there is no need for seperates. Take your budget, and by all means, put it here:

http://usa.denon.com/ProductDetails/AVReceivers.asp

I don't know about all of these rules. I have one I go by, but it is MY own rule. I like to go a little over the "maximum" recommended power. 25w is enough for me. But, sometimes the budget comes into play. My speakers give a spec of 110-180 recommended power. I went with 175w. Works great.

 

[rolyasm]

This site has several pages on the Earthquake.:
http://www.hometheatermag.com/poweramplifiers/905earthquake/index2.html
you will have to find the tab on the bottom to read the rest.

Here is another site on the 5 channel, which is almost the same as the 7 channel. Both put out around 320 w/channel. So for just under $3,000, it is probably overkill for you. You could get a three and five channel for about the same price, but that is taking up a lot of room with 2 amps of that size.
http://www.hometheaterhifi.com/volume_11_4/earthquake-cinenova-grande-power-amplifier-10-2004.html

 

[PENG]

From this statement, I see there is no receiver/pre-pro yet. I also believe there is no need for seperates. Take your budget, and by all means, put it here:

http://usa.denon.com/ProductDetails/AVReceivers.asp

I don't know about all of these rules. I have one I go by, but it is MY own rule. I like to go a little over the "maximum" recommended power. 25w is enough for me. But, sometimes the budget comes into play. My speakers give a spec of 110-180 recommended power. I went with 175w. Works great.

That makes sense to me too.

 

[Josuah]

My personal preference is separates, although the really expensive flagship models from some brands are equal in quality I would imagine. The only reason I would prefer separates is to be able to upgrade the processor later on (either with replacement or firmware upgrades) while keeping the amplifier. Although some would say separates also provide better quality. I haven't listened to enough to say the same. The ones I have used myself have done so.

 

[MacManNM]

well, when you're matching a power amp to a speaker, a good rule of thumb is to pick an amplifier that can deliver power equal to twice the speaker's power rating. So in this case shouldn't be the amp rated at least 200w/ch? Using an amp with some extra "headroom" will help assure that only clean, undistorted power gets to my speakers - correct? The exact opposite would damage the speakers (clipping of an amp).

Clipping per se will not hurt the speakers, what will hurt them is power. A 100w amp fully clipped will deliver 200 watts of RMS power to the speakers this is what will blow them. The output basicly turns into a square wave, hence increasing the rms power. The extra headroom is nice but you will hear the speakers bottoming out. I would go with 110-140 W/ch. This should do you fine. In reality any of todays decent receivers will do a fine job driving your speakers. If you want seperates because of the look (which I personally love) I'd go with a couple Adcom or similar amps. The bottom line is: All of the amps you have listed will do the job, but dont expect them to sound different from each other.

 

[zumbo]

I am using the 5-channel version of this amp. One cool thing about Adcom, is the distortion led's. They light up just before clipping. So you know when you have reached the amps limit before there is any speaker damage.

http://www.adcom.com/newproducts/gfa7607.htm

http://www.adcom.com/pdfs/gfa760x_manual_v1.pdf

 

[rolyasm]

Earthquake also has the lights that warn about approaching clipping. I have seen them come on but didn't push the speakers further. It might have been interesting to try.
Roly

 

[PENG]

My 200W PC Adcom's red lights have never come on even when occasionally I have had the volume up passed 0, driving 87 dB sensitivity floor standing speakers.