Help with selecting a power amp

[walter duque]

I think your 500WPC amp is very marginal.

If you think so then it must be. It's been with me about 17 years. Yes it's old, but still does the job.

Product Review

For instance, even though digital 5.1 surround formats may occasionally take advantage of the dynamic capabilities of rear channels, seldom do the front and rear channels simultaneously require full output. With the power reserves of this amp, you could drive all channels to ridiculous output levels at once, but it probably won't occur in the real world, and if it does, you might think you are on a different planet. The power supply is capable of delivering three thousand watts to six channels (500 watts each) at 4 Ohms, and when combined with the quality of parts and competent circuit design, makes the performance of this amplifier in two-channel listening not only very good, but almost astounding.

http://www.abamps.com/amplifiers.html#800-2

 

[Alex2507]

I think your 500WPC amp is very marginal.

I'm thinking there's more to this than meets the eye.
Oh ... I can see the future ... there is math in this future.

 

[mtrycrafts]

... there's more to this than meets the eye.
....

Transformers?

 

[walter duque]

Would be interesting to know what kind of power amp (amps) did you guys use in your HT in 97. Feel free to post. Could very well be a short list or maybe no list at all.

 

[RichB]

Would be interesting to know what kind of power amp (amps) did you guys use in your HT in 97. Feel free to post. Could very well be a short list or maybe no list at all.

Sunfire Cinema Grand, then a Cinema grand Signature in 2000 or somewhere around that time.

- Rich

 

[PENG]

If you think so then it must be. It's been with me about 17 years. Yes it's old, but still does the job.

Thanks for he link, and I read it. 500W is likely marginal based on the following assumptions.

1. Your speaker's sensitivity is 90 dB/W at 1 meter (you know for every 3 dB above or below your calculated power requirement will change by a factor of 2X or 0.5X.

2. You listened to at least 110 dB plus for some movie tracks per your post (implied).

3. Ignore the spl contribution by your subs.

4. You sit at 3 meter from your front speakers.

5. Your room gain is 3 dB.

6. Your amps are not current limited so ignore the effects of 4 ohm speakers vs 8 ohms.

If you use the Crown audio calculator, you would need:

Amplifier Power Required Calculator

900W, or 1796W to have 3 dB headroom as recommended by Crown.

With 3 dB room gain, that reduces to 447W (from my own spreadsheet) or 894W with 3 dB headroom.

Since you likely have super subs helping and have at least 5 speakers so 500W is fine, but could still clip at times during peaks whether the effects are audible or not, hence "marginal". Turn the volume down a little, everything will be perfect.

 

[walter duque]

Sunfire Cinema Grand, then a Cinema grand Signature in 2000 or somewhere around that time.

- Rich

Great amps. Did listen to a Sunfire amp years ago driving Legacy speakers and it sounded awesome. IMO as least as good as Cinepro or even better. I was impressed.

 

[walter duque]

Thanks for he link, and I read it. 500W is likely marginal based on the following assumptions.

1. Your speaker's sensitivity is 90 dB/W at 1 meter (you know for every 3 dB above or below your calculated power requirement will change by a factor of 2X or 0.5X.

2. You listened to at least 110 dB plus for some movie tracks per your post (implied).

3. Ignore the spl contribution by your subs.

4. You sit at 3 meter from your front speakers.

5. Your room gain is 3 dB.

6. Your amps are not current limited so ignore the effects of 4 ohm speakers vs 8 ohms.

If you use the Crown audio calculator, you would need:

Amplifier Power Required Calculator

900W, or 1796W to have 3 dB headroom as recommended by Crown.

With 3 dB room gain, that reduces to 447W (from my own spreadsheet) or 894W with 3 dB headroom.

Since you likely have super subs helping and have at least 5 speakers so 500W is fine, but could still clip at times during peaks whether the effects are audible or not, hence "marginal". Turn the volume down a little, everything will be perfect.

You're right I can drive them into clipping mode at times when I go a little crazy. Besides I am running my whole system of a 15 amp circuit breaker. That's 2 bedrooms and the living room on that same breaker, where the 3K6 alone needs over 5000 volts at max. power. I also have a 1K2 and the AB 800.2 and of course the display and DVD player running off the same breaker. These amps run best at 220 volts. I am working on a couple of these http://www.powermodules.com/mb-500.html (at least 2). These are out of production, but there are still a few left. A friend of mine knows David very well and of course I am looking for a good deal, like always. I've owned one of his amps in the past (84 to be exact) and it was just amazing. Bought it at Hollywood Sound in Fla. A few years ago I put in on Audiogon and he bought it back since it was still in like new condition. I left the amp on for 13 years without ever turning it off and never a problem.

 

[Saturn94]

Would be interesting to know what kind of power amp (amps) did you guys use in your HT in 97. Feel free to post. Could very well be a short list or maybe no list at all.

Hafler DH200's.