2. home-theater
  3. 1110258552

Setting 6-ch. levels isn't as easy as you think

A not-so-rhetorical question for us multichannel fans--just what do you use to set levels?

Why do I ask? A few weeks ago I auditioned a particular high-end preamp, comparing it with my Marantz AV9000 pre/pro that has been in my system for 5 years or so. I was concerned that it might be handicapping my entire system; turned out it wasn’t much, but I pursued the matter, apparently suffering from a flareup of upgraditis. I decided to simplify my system a little and bought an all-analog 6-channel preamp* that’s arriving tomorrow. It has no interchannel level-setting capability, so I’ll need to use the level- and distance-setting features of my DVD player, a Denon DVD 2900. After I bought the preamp, I read something somewhere that lead me to believe the 2900's level setting does NOT affect SACD output, only DVD-A and DVD-V (DTS and DD) output. Hmm...that is NOT good! I better find an SACD with reference levels on it. Oh boy...there are 2 that I and others can find–-the Telarc Tchaikovsky 1812 (#SACD-60541) and the DMP surround sampler (#20016SACD). After visiting 3 large retailers in the Phoenix area and NOT finding either, my friend found the Telarc at Best Buy. Now I have 3 discs to use to send 6-channel levels to my pre/pro**--The Telarc ‘1812' SACD, the Chesky Ultimate Surround Sampler & 5.1 Set-Up Disc DVD-A (#CHDVD221), and the DTS Technology Music Demonstration and Set-Up Disc (#DTS-CD 96091), PLUS the generator inside the 2900. BTW, I’m using a Phonic Personal Audio Assistant 2 set on C-weighting to sense these levels at the listening position.

To get to one point, I’m highly relieved that the 2900 does indeed adjust SACD levels as well as those of DVD-As and DVD-Vs. So this 6-channel preamp will work, yes? Problem solved, yes? Well, yes and no. Have you ever had to choose to believe ONE liar of many? That’s sort of where I am now. Fortunately, all 4 levels sources are virtually identical for the front 3 channels, but the surround channels aren’t so lucky. They’re about 4-1/2 dB different from lowest to highest, with the Chesky DVD-A having the lowest and the DTS disc having the highest. However the big issue is the LFE-channel level--they’re FOURTEEN dB different, with the DTS disc and the 2900 generator about equal and high, and the 2 hi-res discs about equal and low.

Anyone know why? Do these different coding systems use such different standards? Do I have something set incorrectly somewhere? (Believe me, I’ve looked.) HELP!!!!!!!!!!!!!!!!

* an Audio Refinement Pre-5
** It's set on 6-channel bypass for all of this, and all levels are zerod and all distances are set on 10 feet.
128x128jeffreybehr
eldartford
4,262 posts
 
LFE levels are all over the place, and of course, SW level is greatly affected by the room. I would do it by ear.

One problem that I encountered relates to frequency response. By this I mean room effects: not the equipment. I recently installed equalizers, front and rear, to solve this problem, and I discovered that the usual bass boost from the room had been markedly affecting the measured SPL, so that my level matching was not right. After equalization with new level adjustments, a great improvement was evident. Bottom line is...don't sweat exact level matching until you have taken care of room effects.
maxcast
95 posts
 
I know the .1 channel is very quirky. In SACD it should have the same output as the other channels. With DD (maybe DTS too) the .1 channel is recorded 10db down and the decoder is supposed to add in 10db for playback. This received a lot of discussion when universals first came out.

I thought Denon has a "bass bost" for this situation???

I have the same pre-5. I set up SACD just fine. Popped in a DVD for the kids and the bass was gone. I said screw it and went upstairs to play the DVD.
jeffreybehr's avatar
jeffreybehr OP
805 posts
 
I decided to pick one--the Chesky DVD-A--and live with it. If movies have too much bass, I'll reset the level for that movie.

Maxcast, no bass with a DVD-V is NOT my problem--they have too much.

The preamp sounds great, BTW.
.
rex
245 posts
 
Welcome to multi-channel music. This is one of the many reasons why a lot of audiophiles stick with 2ch - MC is still "half-baked."

Your choices at this point are to pick a compromise level that does justice to nothing but won't drive you too crazy, or tweak for every disc. Not much else you can do.
More to discover