SACD bass calibration problem

[joema]

I'm getting wildly inconsistent bass output levels between CDs, DVDs, and SACDs. I have a VTF-3R, Yamaha RX-V1400 receiver, Sony DVP-NC685V SACD/DVD player, V, Inc DVD player, and Axiom M60/VP150/QS8 speakers.

I think the problem is between SACDs and everything else. I don't know if it's the player or disc, but multichannel SACD bass generally plays back at least -10db down from the other tracks.

If correct this is obviously a serious complication. I've auto-calibrated using Yamaha's YPAO, manually calibrated using the receivers built-in pink tones, manually calibrated using the Sony SACD player's built-in pink tones, manually calibrated using Digital Video Essentials, etc. All work great for CDs, DVDs, or the DD/DTS 5.1 track on DVD-As.

But it doesn't help SACDs. I can manually compensate and crank up the sub output on the SACD player until it sounds right. Thank goodness it has speaker level adjustment for all six channels, and separate DVD and SACD level adjustments. But doing so has two problems: (1) it pegs the maximum available bass output adjustment on the SACD player (2) it makes true sub calibration impossible for SACD -- you must crank the sub output up/down until it "sounds right".

I'm guessing the problem is a lack of standardization among either SACD content producers or SACD player manufacturers about how to handle the bass channel on multichannel SACD discs. Does anybody know about this?

Conventional calibration using built-in tones or DVDs means nothing if the SACD disc and player don't follow consistent standards in handling the bass channel. Ideally there should simply be adherence to bass management and reproduction standards by SACD content providers and player manufacturers, similar to DD 5.1 soundtracks on DVDs, HDTV audio, etc.

Does this make sense? Has anyone encountered this, or know anything about it?

[Sasha_G]

I can manually compensate and crank up the sub output on the SACD player until it sounds right. Thank goodness it has speaker level adjustment for all six channels, and separate DVD and SACD level adjustments. But doing so has two problems: (1) it pegs the maximum available bass output adjustment on the SACD player

Do you mean the SACD player does not have a fine enough gradation, and simply goes to maximum volume? It seems like you should be able to adjust the volume level in steps on your Sony SACD player, and if you only use that player for SACDs everything would be fine.

[DavidD]

I think this is a common problem with the multichannel audio formats. I know Denon (at least) has implemented a bass boost setting for the 5.1 inputs in their receivers. However, as Sasha said, if you use the multi-channel players outputs only for SACD, and use the digital out for video, then you might be able to compensate by cranking up the '.1' output on your player.

If you're saying that the level vary between SACD recordings, that is a production standardization problem. About the only thing you can do is try to find a setting which is acceptable for all.

[joema]

Do you mean the SACD player does not have a fine enough gradation, and simply goes to maximum volume? It seems like you should be able to adjust the volume level in steps on your Sony SACD player, and if you only use that player for SACDs everything would be fine.No, it's adjustable in 0.5db steps +/- 10db. After maxing it out, bass sounds OK and the overall sound quality is very good. However there are several problems:

(1) To get proper bass you must max out the SACD player bass level, which leaves no further room for calibration.

(2) Such a drastic step shouldn't be necessary in the first place. Resorting to it indicates a fundamental problem in the production/playback chain of SACD material.

(3) You can't calibrate the SACD player bass level with built-in tones or a DVD, since the bass level for those sources don't correspond to the bass level of actual SACD playback.

Evidently SACD bass playback is -10db down from the proper level, at least on my Sony player. I don't know if it's a player problem or a standardization problem with SACD mastering. However I've heard other periodic complaints about this problem, just no official or definitive statement.

The problem isn't common to all multichannel formats. For example, Dolby Digital and DTS 5.1 soundtracks have an adequate bass level.

I'm very suspicious that SACD bass output is about -10db down, when Dolby standards specify that LFE is encoded at -10db and the playback decoder should boost this by +10db to compensate. SACD producers and player manufacturers aren't bound by Dolby standards. But it almost sounds like they tried the same approach and don't have standardization between mastering and playback.

[DavidD]

The problem isn't common to all multichannel formats.

Let me clarify my statement. From what I've heard this is a problem that is common with discrete, uncompressed multichannel formats (SACD and DVD Audio). You're correct that Dolby Digital and DTS are OK.

[Sasha_G]

(3) You can't calibrate the SACD player bass level with built-in tones or a DVD, since the bass level for those sources don't correspond to the bass level of actual SACD playback.

....
I'm very suspicious that SACD bass output is about -10db down, when Dolby standards specify that LFE is encoded at -10db and the playback decoder should boost this by +10db to compensate. SACD producers and player manufacturers aren't bound by Dolby standards. But it almost sounds like they tried the same approach and don't have standardization between mastering and playback.

Very interesting, although sometimes all these formats makes my head spin. I wish the audio industry could just agree on a format and stick with it! Seems like SACD is going through some growing pains.

Regarding the Dolby LFE channel, Secrets of Home Theater and Hi Fi has an interesting article on this. It claims that the Dolby Digital standard has the LFE 10 dB HOTTER than the other channels. They artificially create this boost to make their home systems act like their theater systems, which have the LFE boosted on the soundtrack. In the end, it all sounds like the audio engineer intended, so there is no need to change any settings. :rolleyes:

I have yet to demultiplex a Dolby or SACD stream into WAV files and look at the levels, but their story seems possible. Keep in mind I'm no engineer, but I do have a technical bent and might have some extra time.
See Fig. 4 in this article:
http://www.hometheaterhifi.com/volume_7_2/feature-article-misunderstood-lfe-channel-april-2000.html