Squeezebox sound quality vs CD, and Panny XR55 info

geez...we can't get you guys to start new topic threads. :)

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Originally Posted by cyberbri

Can you explain your test procedure again? What tones, how you measured, speakers on/off, what results you got, etc.? What do you mean "dropped off"? No output above that?

And are you running the sub off of speaker-level inputs, then back out to the mains? Or are you running off the LFE/sub cable?

The Phase issue comes into play with room acoustics, and the timing the bass reaches the listening position from different bass drivers (speakers/sub). If they reach the LP out of phase, you get cancellation at various frequencies.

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I ran the DVE track that does frequency sweep from 15hz-150hz for all 6 speakers + sub. All 6 speakers are set to 'small'.

I put the SPL meter at 80 and it fluctuated from -4 to +4 and dropped to -10 at the points listed previously. I don't know how far it dropped. I suppose I would have to switch the meter to 70 or 60 to find out.

My previous posting of 76-89 is incorrect. It should be 76-84.

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Originally Posted by Grayson73

I ran the DVE track that does frequency sweep from 15hz-150hz for all 6 speakers + sub. All 6 speakers are set to 'small'.

I put the SPL meter at 80 and it fluctuated from -4 to +4 and dropped to -10 at the points listed previously. I don't know how far it dropped. I suppose I would have to switch the meter to 70 or 60 to find out.

My previous posting of 76-89 is incorrect. It should be 76-84.

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Yes, that may be phase. Or it could be acoustics, or a combination of the two.

So it was running all 6 speakers and the LFE at once?


Does it have anything that does the individual channels at once?
Your main focus should be on the left/right mains, and then the center. The surrounds don't matter quite as much compared to the front speakers.

Quote:

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Originally Posted by cyberbri

Yes, that may be phase. Or it could be acoustics, or a combination of the two.

So it was running all 6 speakers and the LFE at once?


Does it have anything that does the individual channels at once?
Your main focus should be on the left/right mains, and then the center. The surrounds don't matter quite as much compared to the front speakers.

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Yes, all 6 and LFE at once. I didn't see anything that would play a bass freq sweep for just mains plus sub in DVE. Maybe I can change it to stereo mode on the DVD and receiver to accomplish this.

Am I trying to find the position and phase where it is loudest at crossover point (100hz)?

Quote:

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Originally Posted by Grayson73

Yes, all 6 and LFE at once. I didn't see anything that would play a bass freq sweep for just mains plus sub in DVE. Maybe I can change it to stereo mode on the DVD and receiver to accomplish this.

Am I trying to find the position and phase where it is loudest at crossover point (100hz)?

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Yes, basically.
It will be out of phase to varying degrees at varying frequencies, depending on the placement of the speakers and the room dimensions/acoustics. You want to minimize this, either with the phase setting on the sub, the speaker and sub distance in the receiver, and placement within the room.

The more out of phase it is, the more drop-out you will have. You want to tweak it so you have the smoothest response possible.

What you can do is rent/buy Avia for the individual channel tones, and/or get specific frequency and sweep tones and burn them to a CD (ie., realmofexcursion.com's downloads).

If you run just the subwoofer, and left+sub and right+sub, you can see if that dip in sound around 100Hz is present when only the sub is playing, or if it only comes into play when the bass is coming from both the sub and the speakers.

I did some more playing around yesterday. When I ran the 6 channel + sub sweep with just the mains and the sub, the response was much flatter than with all 6. I attribute this to having Athena AS-R1 and S2 rears which have a different FR curve.

It will be interesting to see what changes I make to sub phase and the overall FR when I move in July and hook up my 170SEs as surrounds.

Good luck with that!
You should also think about picking up Avia too.
You can download and burn for free individual frequency tones and sweep tones, but Avia is 5.1 DD, and it has a readout on the screen for the sweeps so you can see what frequency different things are happening at. The bass tones are also accurate (level), unlike DVE.