Axiom Home Page Forums General Discussion Advice from Axiom Owners Calibrating Sub : sort of Axiom related.

I need help from the true experts here regarding balancing a subwoofer's output against two different sources.

This may be an impossible problem and a waste of bandwidth, but I'm curious for other's opinions. Here's the deal. I recently upgraded from a POS Kenwood sub to a pretty decent SVS PCi+ 20-39. I *really* like the new sub and have no complaints about it. I suspect I would have the same problem with an EP500/600. Equipment : Pioneer Elite VSX-43TX receiver, Denon DVD-1930CI DVD/CD/SACD/DVD-A player, Axiom M22's and VP150 speakers.

It has to do with calibrating the sub. With the Kenwood, this was pretty much a hopeless battle as I could never get things calibrated consistently and so I gave up until purchasing a better sub. This SVS is perfectly consistent as I'm calibrating, so I'm trying to get things dialed as perfectly as possible. I'm having some difficulty getting my sub output balanced between my receiver and my SACD player. Calibrating at 75db for my speakers, perhaps @78db for the sub with its gain set at perhaps 40%, the sub balance is set to -3.5db on the receiver. That creates a nice and balanced soundstage for the bulk of my listening from sources processed by my receiver. However, I do occasionally enjoy SACD's, and usually run those through the multi-channel input in which my receiver does no processing. So I have to calibrate that through the DVD/SACD player. Here's where the problem comes in. The DVD player's sub output seems significantly lower than that from my receiver. Compounding the problem is that it only has negative adjustments. So to get things balanced I have to really crank down all of the other channels, perhaps -10 or -11db, and leave the sub at 0db. That just barely brings everything in line (never mind the 2-3db bump that I like on the sub), but obviously at a lower volume level. This produces the fun effect of blowing out my eardrums if I forget to lower the volume when switching from the multi-channel input back to digital inputs, since the m/c level is considerably lower.

So I tried going the other way - bumping the sub gain up to perhaps 60% and calibrating on the SACD player. That then works great for the multi-channel sound, but then the receiver has to be calibrated with like -12db of sub output to balance out the sub channel for everything else that it processes. Woe to the person that accidentally hits the 'Direct Output' button and bypasses the receiver calibration - as they might blow out the windows in my den.

So can anyone offer any advice? I imagine the best course of action will be to just split the difference between the two sources. Perhaps set the sub gain in the middle, 50%, and balance the receiver down a bit and the DVD up a bit?

First, I would make very certain that there is no mode for processing the DVD-A/SACD analog ins in your receiver. In mine, I can do bass management, etc on the receiver side of things if I switch it to the correct mode. That's your best case answer.

Other than that, it's a little game of finding the right balance.

BTW, gotta say--40-60% volume on a subwoofer! Man, that's a big room.

I don't have any advice, but I have read that when using bass management on a SACD player, the player may reduce the analog sub (SW) level by typicaly 5 dB, maybe 10 dB depending on the player.

This is so the summation of bass (The standard .1 LFE track and the redirected bass from all the other channels) doesn't overdrive the input on your receiver.

Some receivers let you apply sub level changes per listening mode, which may let you provide correction for this in your preferred SACD listening mode, and then not for movies in your Dolby or DTS modes.

Thanks for the tips! I will check again but I'm pretty sure I had disabled all of the extra processing. I can listen to DVD-A/SACD in two ways on the receiver, either through the digital input or the multi-channel. The digital input is only two-channel stereo - the receiver does the processing and it sounds great.

If I want true,pure multi-channel SACD/DVD-A surround sound, I've got to use the multi-channel inputs and those are not processed in any way by the receiver. And it's that signal where the sub seems too quiet. I also double checked to make sure that the speakers are set to 'Small' on the DVD player, as if they were large it would be routing bass to the mains.

It's not that big of a room, only about 2700 cu/ft. The acoustics are pretty bright though, with lots of windows, hardwood floors and walls.

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First, I would make very certain that there is no mode for processing the DVD-A/SACD analog ins in your receiver. In mine, I can do bass management, etc on the receiver side of things if I switch it to the correct mode. That's your best case answer.

Other than that, it's a little game of finding the right balance.

BTW, gotta say--40-60% volume on a subwoofer! Man, that's a big room.

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Oh, I'm definitely talking about post-processing the analog inputs. And the manual's right--you won't find any unit that uses the SPDIF (coax or Toslink) connection to send multichannel SACD/DVD-A sound.

Hello
are your m22 set as large ?
my recievers sub setup has an option to send the LFE + the bass component of any speaker set as large to the sub. This could maybe cause extra bass to the sub ?

otherwise i was gonna advise set the reciever sub level at +3db, but i dont think mine goes in the plus range.

this probably isnt much help, sorry

Randy

The M22's (as well as the VP150 and Energy surrounds) are set to small.

I've further refined the sub placement and various settings and I think I've reached a workable compromise. I'm still a little perplexed as to why the sub level is so low on the DVD/SACD player's analog-outs...

I've owned this receiver for over 2 years, and have read the manual cover-to-cover many times, but apparently never figured out that you can alter the speaker calibrations in any mode including the multi-channel in for SACD. Bingo! Re-calibrated everything again tonight, with the sub toned down to a more realistic level with the gains on the receiver set back to near normal (instead of like -10). Sounds even better now, and digital vs. SACD volume and balance is spot on. Thanks for that bit of advice about checking on the multi-calibration modes!!

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I don't have any advice, but I have read that when using bass management on a SACD player, the player may reduce the analog sub (SW) level by typicaly 5 dB, maybe 10 dB depending on the player.

This is so the summation of bass (The standard .1 LFE track and the redirected bass from all the other channels) doesn't overdrive the input on your receiver.

Some receivers let you apply sub level changes per listening mode, which may let you provide correction for this in your preferred SACD listening mode, and then not for movies in your Dolby or DTS modes.

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That is terrific news!

I'm glad you found it, and that your Pioneer receiver had this feature. It is helpful in these types of situations with varying source levels.

Congrats on finally finding the optimum setup- now I hope you enjoy it.