Going insane w/Bass Mgmt and SPL issues. Need help

D

darthkringle

Junior Audioholic
Hello all- As always, I'm going crazy trying to get my system to sound as good as it can WITHOUT HAVING TO TWEAK RECEIVER/SPEAKER SETTING ANYMORE!! Okay, now that that is out of my system, on to the basics:

I have Axiom M60/VP150/2xQS8/EP500
I have a Yamaha RX V2400
My room is 20x20x10 (Half cube- Yes I know.....)
My EP500 is set on "flat" and at about 1/3 volume w/the crossover bypassed on the sub.

Now to the issues. If I use auot setup on Yamaha, I consistently get the Fronts, Center, and Rears at nearly max channel trim (+10) and the sub at minimum channel trim (-10), I get Fronts as "large", and the crossover is different every time.

With all this said, I had chosen to bypass Yamaha's auto setup and do it myself. For movies I set everything to small and 80hz crossover, Bass out to sub. For music, I use only the M/60's and EP500 set crossover at 60hz and Bass out to BOTH (this sounds better to me).

Here are my questions:

Based on above information, am I doing anything inaccurately?

When I manually try to set level w/SPL, where do I start the overall receiver volume?

Seems like if I use my personal listening level, I get similar result to auto setup which is all channels maxed out and sub near bottom. That just doesn't seem right for there to be a 20 db difference.

Should I calibrate all channels INCLUDING THE SUB to 75 db? Or just the non sub channels?

W/M60's should I use 80 hz or 60hz? I can only pick one xover for all my speakers (Damn 2400- Where's my HK?)

I know this is quite a bit, but I'm ready to set it and stop stressing about the receiver settings and start thinking about a television upgrade........

Thanks as always for each of your help. You guys are great.
 
M

MDS

Audioholic Spartan
darthkringle said:
When I manually try to set level w/SPL, where do I start the overall receiver volume?

Seems like if I use my personal listening level, I get similar result to auto setup which is all channels maxed out and sub near bottom. That just doesn't seem right for there to be a 20 db difference.

Should I calibrate all channels INCLUDING THE SUB to 75 db? Or just the non sub channels?
I'll address the manual setup questions, don't have any experience yet with the auto setup receivers.

I. Level 75 dB or 85 dB.
This depends on the source of the test tones you are using.

- The internal test tones of the receiver are at -30 dB. Therefore you want to calibrate such that the SPL meter reads 75 dB (if you want to follow Dolby Reference Level; 75+30=105 dB peak).

- For the AVIA disc, I believe the test tones are also at -30 dB; so do the same as for the internal test tones.

- For the DVE disc, I believe the test tones are at -20 dB (exactly matches the Dolby spec for calibrating reference level); so calibrate such that the SPL meter reads 85 dB.

II. Receiver Volume setting
This depends on how the receiver operates when you use its internal test tones. Many receivers will automatically increase the volume setting to 0dB when you use the test tones so that the actual position of the knob is ignored (the manual usually says if it does so or not). In that case, calibrate to 75 dB.

- If the receiver does not automatically choose a volume setting OR if you use a calibration disc, then you can choose the volume setting. For receivers like that Yamaha that use the relative display (-infinity to +something), the convention is to set it to 0dB. For receivers that only use absolute volume display (eg. 0-80), a good rule of thumb is to choose a number somewhere around 80% of its range.

Note that 85 dB is quite loud and annoying for test tones, but you can achieve the same reference level calibration using a lower setting. For example, say you choose 0 dB on the volume knob to be the position for reference level playback of 85 dB but can't stand the noise while doing it. Set the volume control to -20 and calibrate so the SPL meter reads 65 dB.

I would do all the speakers first and ignore the sub. Then do the sub afterwards. The sub should technically be calibrated to the same level, but some people like it a little hotter - personal preference. If you were getting a -10 level for the sub channel, then you may need to turn the sub volume control down. It's not that it won't work or won't be equal to the other speakers, but some subs have trouble with their auto-on feature when the signal level is so low.
 
D

darthkringle

Junior Audioholic
Hey MDS, I'm also in Austin!! (Dell). Thanks for the advice, now I just need my wife to leave for a day so I can do all this.
 
Jase

Jase

Junior Audioholic
MDS said:
- For the AVIA disc, I believe the test tones are also at -30 dB; so do the same as for the internal test tones.

- For the DVE disc, I believe the test tones are at -20 dB (exactly matches the Dolby spec for calibrating reference level); so calibrate such that the SPL meter reads 85 dB.
Other way around. 85db for AVIA, 75db for DVE and internal test tones. :)
 
M

MDS

Audioholic Spartan
Jase said:
Other way around. 85db for AVIA, 75db for DVE and internal test tones. :)
Thanks for the correction. I always get it backwards, probably because lately I've just been using the internal test tones. Note to self: AVIA is at -20 and DVE is at -30. Maybe I need to devise an mnemonic like 'DVE Internal' to remember DVE is the same level as the internal test tones.
 

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