Why the Bass Problem?

If you use a player/receiver/pre-pro combo that includes HDMI and/or firewire, then I believe the problem is resolved. I have an analogue output setup and I solved my bass problem with a disc from Pentatone (an SACD classical sampler with test tones specific for SACD). Since then, I've had no trouble with SACD or DVD-A (I have a separate player for CD playback, so I haven't noticed a problem with CDs--I could try a few CDs on my hi-res audio player and get back to you if you'd like).

The reason is most use a home theater setup to listen to surround sound music. Movies have the LFE at -10dB and the receiver or pre/pro adds the +10dB back. So this is an attempt to make SACDs work within this setup.

Because you haven't calibrated the system correctly. The LFE is deliberately recorded "low" to force you to turn it up - then it can make a really loud noise if necessary. (But see below).


This shouldn't be necessary. It's not the format's problem at all. In fact, on SACD the LFE isn't actually recorded 10dB low, it's that the player is lowering it 10dB to make it the normal LFE level (to match all other formats). If you were using the multichannel input for Dolby Digital, DTS, or DVD-Audio, the receiver would be requiring the +10dB/+15dB boost. So an SACD player, or a multi-format player supporting SACD, adjusts its output to match those.

Presumably, you are using the multichannel inputs for SACD, and only for SACD. It's the multichannel input that needs adjustment. You just need to turn up the multichannel subwoofer input by 10dB or 15dB. Don't adjust your subwoofer output level, as that will affect all the other sources. It should be set-and-forget.

Also, make sure bass management is enabled in the player.

Its possible you may have a deficient receiver that doesn't give you independent control of the multichannel inputs, or you might have a deficient player without bass management. Then you'll have a problem.

Actually, once you know what the problem is, and if you have a receiver that allows different settings for different inputs, the problem is easy to resolve.

For example, I happen to have a Denon receiver. In the setup menu, it specifically asks whether or not I want to add a boost (up to +15) for the external inputs (which I do). Playing SACDs works fine.

I personally have noticed a loss of LFE in Mulitch SACD via HDMI with my PS3. Same disc, in 2ch mode gives good deep bass. switch to the Multich layer and maintain the same MV, the bass is significantly less than the 2ch mode.

You're basically right, Jacob, but the manufacturers are allowing for the fact that some channel level adjustment may be required, particularly for the subwoofer channel. There's still a pure-analogue path, they just allow a different set of final amplifier levels to be selected for that input.

In terms of user interface, some receivers have a separate set of level controls for EXT IN, which are used in place of the normal set, and some treat it as an extra input adjustment which is added to the standard output set. But I suspect the underlying implementation is the same.

If it was totally "pure", the master volume control wouldn't work.

My receiver (an Integra DTR 6.4) applies bass management to the analogue MCH input (so I don't use the bass management of the player) BUT the level setting controls do NOT work on the receiver's MCH input--so I have to set the player's subwoofer level to the appropriate setting. However, that only comes into play when I use the player's analogue output (whenever I use the digital output--movies, mainly--the receiver's level settings are active, so it doesn't cause me any interference). However your system works, you have identified one of the major obstacles for mainstream MCH hi-res audio adoption. It SHOULD be as simple as it is with standard DVD.

You mean subwoofer output. Please don't get terminology confused.

Do they really not have this? I've never seen a device with multichannel output that doesn't have level calibration. What player is it?

If nothing else, you should be able to turn all the other channels down to restore balance, although it will mean turning your master volume up higher.

Harman Kardon AVR-520, right? Looking at the online manual, page 33, it suggests that there's one lot of level adjustment done directly via buttons, and then another lot accessed via CHANNEL ADJUST on the on-screen menu. That second lot is claimed to be settable for "each digital and analogue surround mode". Maybe that includes the 6-Channel Direct Input.

I believe that function is similar to my receiver--I can set the levels in the main set up area (they are permanent unless I clear them or the power is out for an extended period)--but I can also "adjust on the fly'' for each input (though that is lost if the receiver is turned off, for sure, or perhaps even if I change inputs--I've not tried it). In any case, level settings are NOT available for me on the MCH input (I get a scrolling message saying that function is not available on the receiver's display). They may be available on the HKs though. I know some Pioneer receivers allow level settings on the MCH analogue inputs BUT don't allow anything else (opposite of mine). It's really too bad they couldn't (or rather, wouldn't) work out a standard before releasing these products.

Actually the correct terminology would be LFE INPUT, as the boost should be happening at that stages on the receiving end.

Not if your using BM in the player. It becomes a SW when LFE is combined with the low bass from the other channels. It can only be LFE when all channel are set to large...

Mark

I guess one can make a distinctiction like that, but it is the LFE part of the combined SW output that remains low by design.

The combined SW output has to be low too, to incorporate the LFE. Whichever device is summing LFE and main channel bass has to be aware of the 10dB difference, and either raise the LFE to match the main bass or lower the main bass to match the LFE. The latter is the norm in an external decoder.

Simple solution - drop the LFE channel altogether as redundant audio info and redundant solution to bass managment already (most likely) implemented in your amp.

Well normally you need a +10db boost if no BM is used on the player, if it is used, then you need +15db, since as you pointed out the player lowers the total output even further. I have no idea how the receiver sort this out, but at the end it has to mantain the 10db offset[boost] for the LFE to be balanced, compared to the redirected bass, and other channels as well.