Hi-Rez Audio – Are you getting all your Bass?

[JonFo]

For those of us with SACD / DVD-Audio players, whether universal or not, the question of bass management keeps coming up, and over the years, the players have handled this issue with varying degrees of accuracy (if handled at all).


But the kicker is that many players that do feature ‘bass management’ on their analog outs, actually get it wrong when it comes to the level of the subwoofer output on hi-rez discs (SACD / DVD-A).

I bring this up, since some recent releases on SACD have some people claiming they are too bright or sharp, and others disagreeing.
I took this to mean that many people have the sub level out of their player waaay too low. Not their fault, but it is a problem one should be aware of and correct if possible.

The problem of sub levels is particularly evident on ‘universal’ players, who tend to implement the sub out levels per the DVD-Video spec and leave them at –10dB relative to the other channels, expecting the pre-pro to boost that during its bass management.

A good example of this is the Denon universals prior to the DVD-2200. Even these highly regarded units, such as the DVD-2900 that I have, have this error. That is, the .1 analog output is a full 10 dB down relative to the L/C/R/Rs/Ls channels when playing SACD or DVD-A.

This means that either the down-stream equipment will boost that signal by +10db or if not, then you must adjust your player to compensate.

For instance, what I did in my Denon (via its setup menu) was to lower the L/C/R/Rs/Ls channels by –10dB, thus compensating for the low .1 output. Totally transformed the reproduction of SACD’s.

So do yourself a favor and double check your players handling of bass, you might find you have been missing something.

Here is a great article that goes into depth on the whole bass management concepts and the various implementations.
It really shows why this is a problem so often.

So dive into the setup menus, now.

 

[Bimotarich]

Thanks for the link!

Good read! My Denon 3300 DVD-A player does luckily feature bass management and after a bit of work I have it dialed in well enough... my SACD player (sony DVD-9000ES) is only a two channel out player so no bass management there... but my MLs handle it well enough...
I hope to get the a newer Universal Player and AV amp that can be connected digitally, but well all it takes is money LOL... so it will be awhile...

Again thanks for the link!

 

[JohnA]

Good point.
It prompted me to revisit my DVD (and SACD) 'bass management' settings.
They were all wrong

Apparently what my universal DVD player (Pioneer 989) thinks is NOT what comes out of the speakers in reality. On DVDs and DVDAs it was off by 18db, no wonder they sounded boomy and unnatural ever since I equalised everything according to the DVD player's test signals.

It looks like there are no standards in treating low frequencies, and setting speaker sizes, distances etc can lead to unexpeced bass mgt operations in the background. The Cambridge Audio receiver (used for surround) was making it's own assumptions and 'corrections' so the end result was a mess for DVDs and DVDAs (mainly)

Now they sound a bit more realistic.

I am still perplexed as to how setting everything from the DVD player's test tone menu can lead to such a mess when all subsequent connections are supposed to be 'direct' and 'straight through'

 

[JonFo]

John, this is why I brought this up. It’s far from simple, even when all gear is designed correctly. And as discussed, quite often they are not.
Sounds like your AVR is doing the +10 (or even a +15) on the analog in’s.

I started the same thread topic over on AVSForum, in the multichannel music section, as that’s the target audience that might care about getting this right. Plenty of additional input, sample cases and discussion there.
http://www.avsforum.com/avs-vb/showthread.php?t=933825


I’ll copy paste a useful summary from that thread that hopefully clarifies why there is a problem comparing the DVD-V digital interconnect supplied signals to the multichannel analog outs.

"DVD-Audio/HD DVD/Blu-ray's bass is too quiet"
No. They're mixed exactly the same way as Dolby Digital or DTS on DVD-Video. The LFE track is recorded 10dB low. People are only noticing a problem because they've switched from a DD/DTS bitstream link which works to a multichannel interconnect lacking the necessary 10dB-15dB boost. If they had been listening to DD or DTS decoded in the player through the multichannel interconnect they'd have seen the same problem. And the problem is that their receiver isn't boosting its SW/LFE input sufficiently.

It is not really an option for the player to boost its analogue SW output, as it would be in danger of overloading a receiver's input circuitry when a maximum volume LFE signal appeared - feeding a 6 volt signal into a nominally 2 volt input. You might get away with it if the amplifier was purely doing an analogue passthrough, but it would overload any receiver with multichannel ADCs.

And similarly the player absolutely cannot boost its digital LFE output. There's no headroom to do this.

And here is a great chart of the various permutations of multichannel bass management scenarios.

There are two different scenarios:

1) speakers set to LARGE:

No bass is mixed.
LFE channel is output at -10db lower than the Main Channels

AVR needs to boost the SUB channel input by +10db​

2) speakers set to small:

LFE channel is lowered by -5db
Redirected Bass from main channels is lowered by -15db
Both LFE and Redirected Bass is mixed at this level
LFE+Redirected Bass is output at -15 lower than the Main Channels

AVR needs to boost the SUB channel input by +15db​

-------------------------

In the case of SACD playback, due to the LFE channel being mastered at the same level as the mains, most players will do this:

1) speakers set to LARGE:

No bass is mixed.
LFE channel is lowered by -10db
LFE channel is output at -10db lower than the Main Channels

AVR needs to boost the SUB channel input by +10db​

2) speakers set to small:

LFE channel is lowered by -15db
Redirected Bass from main channels is lowered by -15db
Both LFE and Redirected Bass is mixed at this level
LFE+Redirected Bass is output at -15 lower than the Main Channels

AVR needs to boost the SUB channel input by +15db​

There are some SACD players that do not do this so it changes to this:

1) speakers set to LARGE:

No bass is mixed.
LFE channel is output at the same level as the Main Channels

AVR needs to boost the SUB channel input by +0db​

2) speakers set to small:

LFE channel is lowered by -5db
Redirected Bass from main channels is lowered by -5db
Both LFE and Redirected Bass is mixed at this level
LFE+Redirected Bass is output at -5 lower than the Main Channels

AVR needs to boost the SUB channel input by +5db​

Complex enough for everyone?

 

[ScottG]

Complex enough for everyone?

I see a service opportunity for on-site help... Audio Doctor anyone?

Most folks on this site love to measure, turn knobs, re-measure... but the average Joe/Jane 6-pack... they are totaly missing the full range of what their equipment has to offer

:think: But, on second thought... the average Joe/Jane 6-pack thinks the sound quality coming from their iPOD is totaly awesome.

sigh

 

[JohnA]

What a mess...

Now that I'm looking closely I realise that I had fallen foul of these misunderstandings ...
It gets worse, because not all recording engineers make the same assumptions. Especially in DVDs and DVD-As.

Here's one good thing about standards: we've got lots of them

 

[JohnA]

Just found this interesting post on bass management

It clearly explains the reasoning behind LFE boost and leaves us muddled even further...

 

[timm]

For those of us with SACD / DVD-Audio players, whether universal or not, the question of bass management keeps coming up, and over the years, the players have handled this issue with varying degrees of accuracy (if handled at all).


But the kicker is that many players that do feature ‘bass management’ on their analog outs, actually get it wrong when it comes to the level of the subwoofer output on hi-rez discs (SACD / DVD-A).

I bring this up, since some recent releases on SACD have some people claiming they are too bright or sharp, and others disagreeing.
I took this to mean that many people have the sub level out of their player waaay too low. Not their fault, but it is a problem one should be aware of and correct if possible.

The problem of sub levels is particularly evident on ‘universal’ players, who tend to implement the sub out levels per the DVD-Video spec and leave them at –10dB relative to the other channels, expecting the pre-pro to boost that during its bass management.

A good example of this is the Denon universals prior to the DVD-2200. Even these highly regarded units, such as the DVD-2900 that I have, have this error. That is, the .1 analog output is a full 10 dB down relative to the L/C/R/Rs/Ls channels when playing SACD or DVD-A.

This means that either the down-stream equipment will boost that signal by +10db or if not, then you must adjust your player to compensate.

For instance, what I did in my Denon (via its setup menu) was to lower the L/C/R/Rs/Ls channels by –10dB, thus compensating for the low .1 output. Totally transformed the reproduction of SACD’s.

So do yourself a favor and double check your players handling of bass, you might find you have been missing something.

Here is a great article that goes into depth on the whole bass management concepts and the various implementations.
It really shows why this is a problem so often.

So dive into the setup menus, now.

JonFo - I have the Denon 5900 -- there is a +10 db setting on the subwoofer output on the analog out. Does the 2900 not have this - or am I missing something? I try to handle it thru the player - and not try to continue to manipulate the settings on the processor - since I then get into the problem of altering it for every CD/SACD/DVD-A I have. I think the +10 db setting is for SACD only... I'd have to double check that.... But, in any case - I have the sub set so it disappears - and I never make any adjustments for anything. Sometimes if I want a movie to really boom - I will bump my sub level on the processor - but that is it...

 

[JonFo]

JonFo - I have the Denon 5900 -- there is a +10 db setting on the subwoofer output on the analog out. Does the 2900 not have this - or am I missing something? I try to handle it thru the player - and not try to continue to manipulate the settings on the processor - since I then get into the problem of altering it for every CD/SACD/DVD-A I have. I think the +10 db setting is for SACD only... I'd have to double check that.... But, in any case - I have the sub set so it disappears - and I never make any adjustments for anything. Sometimes if I want a movie to really boom - I will bump my sub level on the processor - but that is it...

Timm, I believe all Denon’s from the 2200 onward have the +10 control you mention, in which case, you are covered.
As you noted, it is additive for SACD (and I believe also for DVD-A, but maybe each type has its own preference). SACD definitely needs it on, and I would say so does DVD-A.

If your player has this control (the +10), then it's definitely the place to do it.