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Discussion Starter · #1 ·
I'm hoping someone can point me to a good discussion on mixing separate amps. I have a B&K 200.7 but would like more SPL out of my PSB Synchrony One's. I have the towers, surrounds, and center, paired with some lower end surround backs for a 7.1 system. Sunfire sub.


Specifically, I'm wondering about adding an Emotiva XPA-2 for more power on the towers but curious about how that may impact my 5.1/7.1 listening. I mean, with the towers run at Emo 500W (4 ohm) vs the center and surrounds running at B&K 375W (4 ohm), won't the towers overpower the other channels? Also, if I use Audessy, will these channels just be attenuated putting me back to square one?


Thanks in advance guys, let me know if I've left any pertinent details out... I'm sure I have.
 

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Replacing a 375W/4R amp with a 500W/4R amp will mean you'll potentially get another 1.25dB SPL before clipping. Not a real lot; 3dB (2x power) is a worthwhile increase and 10dB (10x power) is double apparent loudness.


If the gains on the amps/system are set correctly, it will be the same as now, except when the signal gets into that last 1.25dB on the speakers with the higher power amp.
 

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Discussion Starter · #3 ·

Quote:
Originally Posted by A9X-308 /forum/post/16914312


Replacing a 375W/4R amp with a 500W/4R amp will mean you'll potentially get another 1.25dB SPL before clipping. Not a real lot; 3dB (2x power) is a worthwhile increase and 10dB (10x power) is double apparent loudness.


If the gains on the amps/system are set correctly, it will be the same as now, except when the signal gets into that last 1.25dB on the speakers with the higher power amp.

So I'd have to go to dual monoblock XPA-1's before it's worthwhile, and even then I won't notice the difference until I'm really pumping it up? I should throw in the caveat that I need two more channels of amplification anyway, for some outdoor speakercrafts, so I could use two of the B&K channels or two new channels... good feedback though!
 

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Quote:
Originally Posted by AI Limited /forum/post/16914365


So I'd have to go to dual monoblock XPA-1's before it's worthwhile, and even then I won't notice the difference until I'm really pumping it up?

Pretty much. If you're not hearing it clip now, then I doubt you'll hear a difference at all.

Quote:
Originally Posted by AI Limited /forum/post/16914365


I should throw in the caveat that I need two more channels of amplification anyway, for some outdoor speakercrafts, so I could use two of the B&K channels or two new channels... good feedback though!

That may work for you then.


FTR, power ratings are linear, but as you may know, we hear logarithmically, so a 100W amp is 20dBW, a 200W amp 23dBW and 1kW is 30dBW. Makes it easier to work out SPL.


dBW = 10*log (power)


Cheers
 

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Discussion Starter · #5 ·
FWIW, I purchased an Emotiva XPA-2 for my mains and used 2 of the B&K 200.7 channels for the outside speakers. The Emotiva seemed to run my mains MUCH louder than the B&K upon initial setup. My perceptions were confirmed when I ran Audessy and it knocked the mains down by 10 dB... makes me want to replace my 200.7 with a few XPA-2's!
 

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Quote:
Originally Posted by AI Limited /forum/post/17148383


FWIW, I purchased an Emotiva XPA-2 for my mains and used 2 of the B&K 200.7 channels for the outside speakers. The Emotiva seemed to run my mains MUCH louder than the B&K upon initial setup. My perceptions were confirmed when I ran Audessy and it knocked the mains down by 10 dB... makes me want to replace my 200.7 with a few XPA-2's!

The difference that you hear (and see) might have at least something to do with the differences in sensitivity and gain between the two amps.


The Emotive outputs 208 Watts with 1.05V input (31.8dB gain) while the B&K requires 1.4V (28dB gain) to output 200 Watts. So at whatever voltage is output from the pre-amp at Audyessy setup the channels driven by the Emotive should be about trimmed at least -3dB compared to the B&K.


The assumption here is that both makers test under identical conditions.
 
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