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Post by brockjon on Jun 6, 2017 1:40:59 GMT -5
I just switched front speakers from B&W 802D2s to Verity Audio Parsifals. The Parsifals seems to be considerably less efficient than the 802s. With the 802s, -25 on the XMC-1 was loud; with the Parsifals, I had to go to approximately -15 for the same levels.
When I went to balance my speaker levels using the XMC-1's built in white noise test (@75db), I had to increase the gain for the front speakers by +9. While one way to do it would be to adjust everything to the level of the Parsifals, it would end up making it so I have to turn the whole system up so much higher to achieve the same levels.
I have two questions:
1. Will adding +9 in preamp gain to the front L/R introduce distortion or any loss of fidelity?
2. Would it be wiser for me to use the front L/R as the reference point and turn everything else down (e.g., the center would be around -9)?
Thanks!
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Post by Gary Cook on Jun 6, 2017 14:45:57 GMT -5
Not a big difference but I always prefer to match down rather than up, so I'd suggest option #2. That way there is less chance of over driving those particular channels in the pre amp stage. There is of course a 3rd option, go +4.5 db on the L&R and -4.5 db on the others. That way none deviate as far from neutral.
Cheers
Gary
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Post by Axis on Jun 6, 2017 15:52:49 GMT -5
Does speaker configuration software use main left, right and center for reference volume and set your surrounds to them ? I do not push gains to the upside unless it is absolutely necessary. 75db should be plenty to get it right even if those new front speakers are very inefficient. Maybe they are not a good match for the center.
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Post by MusicHead on Jun 6, 2017 16:40:07 GMT -5
Would not a +9dB at the preamp have the potential to increase noise floor as well?
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Post by Axis on Jun 6, 2017 16:46:59 GMT -5
Would not a +9dB at the preamp have the potential to increase noise floor as well? Yes it would but the XMC-1 has a very low noise floor and I doubt you would hear noise even if you pushed it to +9dB. I do not know this gear and that may be just what the Doctor orders. Gary Cook knows and I would follow his advice. |
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klinemj
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Post by klinemj on Jun 6, 2017 17:30:09 GMT -5
I would go with Gary's option #2...I recall a rule of thumb I saw somewhere that said if you had to boost 12 dB, don't...drop the others. 9 is getting mighty close to 12, so...I'd take the others down.
If in the end you can't get the system volume you want, try splitting the middle per Gary's alternate suggestion.
Mark
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Post by Gary Cook on Jun 6, 2017 18:33:16 GMT -5
Would not a +9dB at the preamp have the potential to increase noise floor as well? It doesn't really matter whether the +9db is achieved by individual channels trims or by overall volume increase. The combined listening volume via the pre amp gain is the ultimate determiner of the noise floor. Cheers Gary |
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Post by brockjon on Jun 6, 2017 23:09:35 GMT -5
One way has potential to add preamp (XMC-1) distortion. The other way has potential to add power amp (XPA-2) distortion. Right?
So which is worse?
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