Ok, here we go. This may be my last round in Outlaw. My 'attack' was between ' ' if that still means anything. No need to refer to quotes, I just perceive your approach to my contribution to be downlifting; the word attack in-between these '-hooks thingies or whatever you call them in English seemed appropriate. I apologize if that excited you more than intended.

Note again, my angle is mainly from music recording, and classical music in particular.

QUOTES from answers posted by sdurani:

Quote:

[b]So you're recommending people buy full range speakers for every channel? Which speakers give flat frequency response from 20Hz to...well, however high SACD and DVD-A go?

Yes, I'd certainly try to be full range for all front channels, and in the back, it would be desirable, especiallyt when you listen to multichannel material that has been recorded from the 'in-the-band' viewpoint.

Do I know of 20Hz - 20kHz loudspeakers? Let's view this as a hypothetical question and not as a way to kill the discussion.

We are talking about a satisfying listening experience. This is not always done with just a selection of loudspeakers because they fit on-top the TV. Nor is is done with just a subwoofer. I rather listen to something that is integrated in its sound than something that tries to encompass the so-called human listening bandwidth in technical terms.

Having, especially in classical music, multiple partly decorrelated signals (we're talking about reverberation here), it would indeed be desirable for envelopment to have 5 full-range loudspeakers. Sending this all to the sub will add it up electronically and will reveal the music spectrally more than spatially.

Quote:

If I omit the sub, what do I do with the contents of the LFE channel on my DVD-As, SACDs, DTS music discs, DVD-V concert titles, etc.? Simply disregard it?

From a music perspective: indeed, disregard it. Even for 5-channel music recordings, the LFE channel should not be used for program. It is undesirable that a producer puts the low end of a recording in this channel. You may find that this is the practice for many 5 channel recordings.

At home, the sub is the sub, and not persé the LFE. If the main loudspeakers cannot reproduce low fequency, bass management is indeed desired to REDIRECT the lower frequencies to the sub. This is what a bass management processor is supposed to take care of.

This becomes a problem if the engineer also redirected some of the bass information to the LFE. In that case you double the information, and you may hope that the signals from the LFE channel and the inserted LF is coincident, so you can at least adjust the balance at the playback level of the sub.

In this regard, I noted in one review of the Outlaw bass manager that regardless of the setting for large or small loudspeakers, LF is always redirected to the sub. That would not be desirable.

BTW, this programmatic requirement for program in the 5 channels and non-program LF in the subchannel is also valid for DVD-V. That way, you have control over what is happening. mixing it up, the electronic addition is the final answer that, depending the circumstances, can affect the listening experience negatively.

Quote:

Bass management has nothing to do with how closely the engineer sticks to the "code of the book for 5.1". Instead it has to do with the playback set-ups in people's homes, where very few truly full range speakers exist.

It has everything to do with how things are recorded. As explained above, it is very easy to get double base, or phased base if things go really wrong. It is confusing enough on the consumer side.

Visiting various AES conventions it was astonishing to learn that some of the celebrated engineers did not understand the underlying choices and principles, and that it would be very likely that playing their records would lead weird base. Other engineers were very consious of the rules of the game, and showed how that apparent limitation could lead to great artistic material. Note that this issue omits the fact that the .1 channel for the hi-rez versions is in fact a sixth channel that could be used by a producer in all kinds of ways, including surround center, but also surround ceiling... some liberty will be taken there, and it certainly adds to the fun of multichannel.

Quote:

Why would I want to compromise a DVD-A or SACD title by discarding the low frequencies of the centre and surround channels? Are you saying that the bottom end of those channels is disposable? Also, if I use the REL method and my sub is a different distance away from my main speakers (very common in most homes), I can't compensate for the difference in distance by using time alignment.

Well, at first, I would really try hard to go full-range on the center channel. It is unclear to some recording engineers what to do with it, leading to great comb-filterin issues that heavily narrow the seetspot. If treated as a full channel, which it really should, then the center channel will contain full-range material (orchestra recording, Decca tree et all).

For classical, although undesirable, not having bottom end of the surround then becomes an issue of tonality versus envelopment, and the choice is to the listener. If you 'collapse' the sound from the surounds to the sub, you have to see how it comes out in terms of additive fundament versus distraced spatial information. And that choice may differ per recording. In general, it may be very safe to collapse the low end to the sub.

Time-alignment can be an issue. Delaying the mains to get in line with the sub using digital means would degrade the hi-res signal and is for me not an option. I would stick to reolution above a slight time adjustment for very low frequencies.

Quote:

...In the real world, there are very few speaker set-ups where every single speaker is the same exact distance away from the listener. That's why almost every receiver and pre-pro made today has a time alignment feature.

Right, so for which spot do you time-align the loudspeakers? Again, I opt for moving the loudspeakers before degrading the signal by using another processing device in the chain that can degrade the signal. Yes, it would be great if the players had some processing in them at their resolution before it comes out analog but we probably have to wait for that another while.

Quote:

Rather than reading specs in the code book, why don't you look at actual DVD-A titles that have been released. I have yet to run into a DVD-A that doesn't have 96/24 data in ALL 6 channels. And why should I "hope that it is not lossy coded as well"? The point of DVD-A is to avoid lossy compression altogether, that's why they use MLP encoding (Meridian Lossless Packing).

Good for you. I have heard demo's of DVD-A still using 24/48 in the surrounds. Is this going the same route as the DDD label ;-)

Quote:

We obviously have differing views of how knowledgeable recording engineers are.

You have a lot of confidence in the engineers, or you are just very lucky only listening to the 'right stuff'. The various conferences I attended on the subject sometimes lead to hear-tearing moments.

Perhaps read Tom Holman's book on 5.1. It is already eight (!) years old, but it deals with these fundamentals in a fairly clear way. Or read others...

Quote:

The ICBM doesn't do time alignment. And besides, it does process the signal. Or does the term "processing" no longer apply to analog signal manipulation but only to digital signal manipulation?

Nag nag nag. Is there any willingness on your part to close a subject and see sense in what others contribute? You end many of your arguments by opening-up another subject, or by asking a snarky question.

If you really care about the anwer: I consider everything we do as processing. Fr instance, recording by itself is processing if you consider how the choices for microphone placement have an effect on the spatial character of a recording.

Snarf

[This message has been edited by Snarf (edited July 31, 2003).]

Sharf:

This thread describes how I have dealt with the bass issue:

http://ubb.outlawaudio.com/ubb/Forum4/HTML/000250.html

No need to apologize, I was just curious why asking you questions constituted an attack (your word, not mine). Yes, do you know of any 20Hz - 20kHz loudspeakers? If you're advocvating that folks use full range loudspeakers for every channel, I don't think it's unreasonable to ask for some real-world examples of such loudspeakers. I don't understand why asking for specifics, rather then delving into the hypothetical, would kill the discussion. Why would you have double the information? You make it sound asthough the recording engineer throws redundant information into the LFE channel and doesn't bother to monitor how it balances as part of the entire mix. If the mix was designed to include the LFE content, and that's how it was monitored in the recording studio, then discarding that entire channel will result in less bass than was intented by the recording engineer. It's a little contradictory to advocate changing the mix's original balance by tossing out the contents of an entire channel AND at the same time advocate a purist approach to listening to the signal on DVD-A and SACD discs. Understood, but are you saying that the LFE channel shouldn't be used by recording engineers because one Outlaw product creates double bass? What about all the other processors and receivers that don't have that problem? Why should they have to be saddled with one less channel if they can handle it properly? The examples you give of double bass are for situations where the recording engineer or the bass management system are faulty. Should this faulty behaviour then dictate how DVD-A and SACD discs are made, especially when there are recording engineers and consumer playback systems that are capable of properly handling LFE playback?

If, as you say, bass management "has everything to do with how things are recorded", then where in the recording chain is bass management taken into consideration? The only place is in playback/monitoring. Bass management is a playback tool, to deal with non-full-range speakers, not anything to do with recording. That's a valid choice; we each choose our compromises, and I can't argue against your personal preference. From my personal experience, I'd rather have the slight loss of resolution because I have found it more than compensated for by proper time alignment and bass management. The sweet spot. Whether you achieve proper time alignment by physically moving the speaker or electronically delaying certain channels, your speakers can only be equidistant from one spot. I agree that that would be optimal, requiring no compromise. But please realize that very few consumers, let alone audiophiles, have a set-up where all 5 or 7 speakers (and subs) are exactly the same distance away from the listening area. That may be happening little by little; I think the latest Sony SACD decoding chips contain rudimentary bass management and time alignment. Of course, if there were a hi-res digital interface for DVD-A and SACD, we could send the data from the player into the receiver/pre-pro and treat it as JADS (just another digital signal), rendering most of this conversation moot. OK, but aside from demos, do you know of any DVD-A titles that are configured this way? Again, I hope you don't think that asking for actual examples is my way of killing the discussion. First time I've heard a civil discourse referred to as nagging. I'm perfectly willing to see sense in what others contribute when those contributions make sense. However, things like discarding an entire channel of content during playback, or allowing the peculiarities of an Outlaw product dictate the bass content on SACDs and DVD-As, doesn't make sense.

As for closing subjects; are you asking for your statements go unquestioned? I don't think it's unreasonable to ask for real world examples to support what you're saying. If you don't want to or can't answer questions I raise, then just say so. Subject closed.

Best,
Sanjay

I will not use the Quote function here, but try from the top on the engineer issue. The other aspects are less interesting for the broader audience, I'd think.

Bass management is indeed a tool for playback. Monitoring in the studio is playback. Yet, the thing only works if the rules by which people play are the same. These rules are very simple:
1. Music in all 5 channels, full range
2. Effects for LF in the LFE

These rules are constituted to prevent wrong base playback (and monitoring) and subsequent corrections by engineers and consumers that would make it worse, or that would make them to have different settings for various recording approaches. The rules are bent by engineers who use the LFE channel full range and ask to stick that loudspeaker to one side, center back or on the ceiling. These things will happen and are probably a lot of fun.

Before some further thoughts on this, let me put straight one assumption I made in my previous posting on the features of the Outlaw bass management module. My assuption was wrongfully based on a review that misinterpreted the way the thing was working. The claim was that regardless of the setting for big and small loudspeakers (paraphrasing) the LF content below a certain frequency would be sent to the sub from all other channels. I stated that such an approach would be wrong; the Outlaw bass manager however does not work this way, hence it is not wrong. A friend uses the Outlaw bass manager and explained how it works within his setup. I will lookup the manual tonight to check the final answer on that one, as it seems that the outlaw bass manager offers more layers of flexibility.


Back to the engineer versus manager.


Suppose the following situation (A):
Engineer records music alone, and 'copies' the content of the 5 channels below 80 Hz to the LFE.

This disk is played back on a system that has loudspeakers that do not go under 80 Hz and a subwoofer that is set to play from 80 Hz down to whatever it goes down to. This arrangement would constitute a 'flat' playback system.

The bass manager reroutes the low frequency content of the 5 channels to the sub. The information of the LFE channel is also routed to the sub.

Result: doubling of LF!


Situation B:

Engineer records music alone, and 'copies' the content of the 5 channels below 80 Hz to the LFE.

This disk is played back on a system that has loudspeakers that go as low as 40 Hz and the system includes a subwoofer that is set to play from 40 Hz down to whatever it goes down to for music, and from 80 Hz down for LFE channel information. This arrangement would constitute a 'flat' playback system.

The bass manager reroutes the low frequency content of the 5 channels to the sub. The information of the LFE channel is also routed to the sub.


Result: doubling of 40 to 80 Hz!


These simple examples show that the recording engineer has to stick to the rules to ensure that his sound survives. I would not assume that the recording engineer has full-range setups in the studio (do you know of any loudspeakers that are flat from 20-20k or beyond, by any chance?), but either ignores low frequency in the control room, or makes use of bass management in combination with one or more subwoofers. In that case, you may find that if the recording engineer does not understand the input-end, he may have made-up for it at the output-end in the studio. This may sound fine in the control room, but could result in either very lean or very thick sounding recordings.

Ergo, the engineer does indeed need a manager, yet as with many engineers under managers, they need to know their stuff, 'cause the manager probably won't.

Maybe this is another good moment to plug the Holman book?


Snarf

PS: Am starting to read the Outlaw manual now, but have to 'clear the line'. Must say that the Outlaw product is truly a wonder, especially the fact that you could do with smaller surround (and center) loudspeakers, and reroute their bass content to the front loudspeakers before that is picked-up by a sub (works with a Rel, as it taps the main left and right). In my case, with full-range center you can set the center to bypass the splitting so it stays unchanged while it's LF content is not copied to the sub (it is not entirely clear to me if this is true, have to read some more...). In other words a great product!

The choice of mixing the LF of the surrounds to the front channels is then given by the recording style and approach. I would think that for classical music where the orchesta is 'in front', it may not be desirable to electroncally add the (partly uncorrelated) bass of the surround channels to the front left and right channel, as it potentailly results in less focussed base playback. For an 'in the round' multichannel approach it would probably make a lot of sense to flip the switch and reroute the bass of the surround channels to loudspeakers that can play it. In the round recordings are more popular for pop music than for classical; for the latter it seems somehow interesting for 5 minutes, but for many compositions, it rips the instrumentation apart and makes it difficult to understand the color and the balances that are sought by the musicians.


Enough for today, I'd think.

BTW, it bears mentioning that a lot of disc-makers are supplying full-range signals to the LFE channels in DVD-A/SACD. They shouldn't, but they do.

Jeff

Very nice!

And then I digress a bit...

The section about the historical relevance of the LFE channel is good, especially if you consider that the E stands for effects and not for program (speech and music). In fact, some music recording companies do not use the LFE or sixth channel at all for that specific reason. This is not to say that you may not need a sub, though. A sub is a sub, LFE is only a channel.

There MAY BE another reason to have more subs, and that is tied to the acoustical behavior of the (smaller) space. It turns out that having a sub 'up front' close to the main loudspeakers, but still coupled to the room, and a sub to the side is a good method to find complementary modal responses of the room. I have heard this, and it is quite convincing.

The Rel approach is convincing in that sense too: they almost claim that for a smaller room it is better to get small loudspeakers and then just one or more subs, as that way you have control over the low end. Well, I guess you could do the same thing for less by bi-amping a full-range loudspeaker, although it may be more effective to have separate control over the very low frequencies from a room-acoustics point of view by still adding one (or more) subwoofers. Oh well, it's just money ;-)

No problem; I use it simply because it help me keep my thoughts straight when addressing various points. I think you left out a step: when the recording engineer checks his mix, he hears the bass from all the channels PLUS five channels worth of additional bass coming from the LFE channel. Realizing that that's twice as much bass as he was intending, he adjust all the channels to achieve proper bass balance. Upon playback, none of the low frequencies are discarded, thus preserving the original balance. Or are you saying that recording engineers will copy the low frequency content of 5 channels but won't bother to find how that (rather large) change impacts the mix? In this example, the subwoofer is playing 2 things: derived bass (derived from the other channels) below 40Hz and discrete bass (from the discrete LFE channel) from 80Hz downwards. From 40Hz to 80Hz the sub is only reproducing the LFE signal; no derived bass. How is this "doubling of 40 to 80 Hz"?

I still don't understand what you have against the LFE channel. For it to create the problems you describe, there seems to be a prerequisite of an inept engineer during recording and/or improper bass management during playback. Hey, that's my question. But to answer it, yes I do. However, the few that are truly full range (Infintys, Martin Logans, Dunlavys, etc) are all very large and all use a separate bass enclosure that is almost as big as the speaker itself. Oddly enough, the manufacturers still refer to these two-piece units as one speaker.

Since it is impractical to have 5 of these large speakers in the homes of most consumers, let alone have the room to place each one of them the same distance from the listener, I feel it is practical to apply bass management and time alignment to SACD/DVD-A signals, even if it means digitizing the signal (of course, using high quality A/D and D/A conversion). I don't know if you are aware but pre-pros from Meridian, Lexicon and Mark Levinson ALL digitize a 5.1-channel signal upon input.

As impractical as it is to have 5 or 7 full range speakers at home, it is not that difficult to find affordable subs that go down below 20Hz. With that in mind, it makes more sense to me to process a SACD/DVD-A signal and enjoy the full content of all the channels rather than discard the entire LFE channel. Again, this may all come down to personal preference and what each one of is willing to compromise.

You started your participation in this thread with the claim "For SACD, read listening to music, there is no need to do ANY processing." Rather than reply with something just as definitive, insisting that the signal needs be processed, I instead wanted to point out that there are genuine and practical benefits to processing the signal. Whether you choose to or not is up to the individual listener; there are benefits and compromises to both methods. Again, personal preference.

As for your comments about the 950: That's one are where we are in 100% agreement.

Best,
Sanjay

Last round as far as I'm concerned. I kindly ask to re-read my post because you ask questions that are really answered in there.

1.
You make the assumption that I'm against the LFE. Not at all, but understand please that the E stands for Enhancement read effects. There is NO NEED to put porgrammatically important information in this channel. Do not mix the LFE with the sub. LFE is a channel carrying the signal, the sub is a loudspeaker capable of handling low frequency at decent level.

I like the LFE, because it gives the low frequency effects a chance. Mind you, in historical sense, without the LFE we wouldn't have so many subs to choose from.

The sub is great if your loudspeakers don't carry so low.

2.
I did not leave a step out. I think I assumed in the post that the engineer has a playback system with a bass manager. For him it is a matter of coat pocket versus trouser pocket where the bass manager can be set such that it compensates for the mistake made at the recording. This does then thus not reveal the mistake, since it sounds great in the studio. And of course it does!

The consequence of leaving total freedom at the recording is that the consumer has to change the settings at the bass manager for each and every recording.


3.
Situation B
Well, let me try again to explain this rather simple example:

DC to 80 Hz in the LFE, since the engineer mixed this frequency range in that channel.
40 to 80 Hz from the main loudspeakers, as the bass management is set to match the capability of the loudspeaker.

So, 40 to 80 Hz is played twice!

Note here that the 80 HZ is somewhat arbitrarily. If we keep freedom here, we have to read at the back of the CD at which frequency the engineer has chosen to set his or her crossover in the studio so that we consumer can make adjustments in our system, compensating for our own system layout.


4.
The bad news is: inept engineers exist, and what's worse, they come in bundles of 10. Even worse, some of the celebrated ones (and rightfully so) may make great recordings, but are also still very confused about the issue. May I plug a good read here again?

Bass management at fault, perhaps. But may we at least assume that a consious audio lover has adapted the sub in the specific system to match the other loudspeakers such that it makes for a nice and flat frequency response when listening to music? If that setting is wrong, sure, we have a problem at the home side. It is indeed very likely that it is wrong in many households but I give the audiophiles a chance here

Note the word music, as for DVD-V the LFE is allowed to go up to, I believe 120 Hz for LFE effects. This is why some people have a music and a DVD-V setting, so they optimally enjoy both.

Also note that a badly routed recording will be very difficult to compensate for unless you have an - here it is - Outlaw bass management box and a driver layout that has some room (read range). I hope I don't have to explain this one.


5.
And yes, what a surprize, I know all those loudspeakers you talk about, and can even name a few others. That was not the point of my question...

With the Outlaw bass manager you can enjoy sitting inside a cirlce of handsome standmounted two-ways and a sub or two and decently enjoy full range music. Indeed, the sub is a handy thing, especially with a good bass manager.

But I want that bass manager to be analog unless it can handle the high resolution signals of SACD and, if you like, DVD-A. I would avoid any cascading of AD-DA steps, how good the convertors may sound, even if that is at the cost of handy features. Timing can be solved with schlepping for now.

Personal preference indeed; I'd almost suggest listening to both signal streams (straigh out and via an AD-DA step) carefully, but I won't. All the talk about focus and grain and air and space and envelopment and all that other HiEnd talk should apply there.

6.
My appreciation of the analog bass manager is with regard to the ICBM (or whatever it is called) and not the 950. Is that only 80% off since it still says Outlaw on the outside? Sorry about that, but read the post again and you will see that the specific paragraphs about settings apply to this analog fellow and not the 950.


Snarf

Snarf:

The stereo sub article I did was meant as a good compromise to accommodate exactly this bass mis-management situation on all recordings from CDs to DVDs to multi-channel music without having to set the sub configuration differently for each. The Outlaw ICBM does this too, except that it has a fixed crossover frequency of 80HZ in stereo bass mode.

The LFE track is a movie convention meant for low frequency effects - that's why it was created, and when it was conceived, no thought was given to music reproduction. It has it's roots in the days when the movie "Earthquake" was released - music was never meant to come from it. An interm solution during the release of "Star Wars" in 1977 was to use two of the 5 behind the screen speakers in 70mm theaters as "baby booms" - to act as subwoofers. A stripe on the 70mm film print was devoted to this effects track. I know this from conversations I've had with a film mixing engineer who mixed "The Empire Strikes Back".

You never answered the questions about full range speakers, DVD-A titles with 24/48 surrounds, why there would be bass doubling on pre-pros that handle the LFE signal correctly, etc. Let me get this straight: the recording engineer has double bass in the recording (bass in all 5 channels plus the summed bass copied from ALL channels in the LFE). His studio's professional monitoring set-up does "not reveal the mistake" but a consumer home theatre does? You're really expecting me to believe that no one in the production chain would catch a double bass problem? Yes, inept engineers exist, but they're not a reason to broadly advocate discarding the the LFE channel. Why? Because some engineers might actually know how to use it properly. Or do you not think it's a remote possibility that there are recording engineers that understand how to create a mix using an LFE channel? If the system is set up wrong, then bass problems will occur for all sources, not just DVD-As and SACDs. Bad bass management doesn't discriminate that way. Conversely if "a consious audio lover has adapted the sub in the specific system to match the other loudspeakers such that it makes for a nice and flat frequency response when listening to music", then the frequency response should be flat for 5.1 channel DD & DTS material as well as 5.1 SACD & DVD-A sources. All those sources have LFE channels and the system won't give you double bass on SACDs but not double the bass on DVD-Vs.

You can balance a system around a 5.0 source, where the sub only sees derived bass from the other channels. THEN, introducing the LFE channel would give double bass. But why would anyone do that, especially at a time when the LFE channel is ubiquitous on multi-channel material (music and movies)?

Again, for the your examples of double bass to occur, the prerequisites seem to be: 1) a problematic recording that has twice the bass, because this problem was apparently never caught by the recording and mastering engineers; and/or, 2) a problematic speaker set-up where if you reproduce the bass in all the channels plus the LFE content, you automatically end up with double bass.

By your argument, any system that faithfully reproduces the contents of an SACD (i.e., the full contents of all 6 channels) is automatically doomed to the double-bass problem. And surprise, that's why you didn't name a single one, even though I asked you twice. No need to suggest it; I do it routinely. At the push of a button, I can switch the 5.1 inputs on my pre-pro between the digitized version or pure analog bypass. Can I hear the loss of resolution with the digitizing step? Yes. But it's negligible compared to the benefits that proper bass management and time alignment give. Based on listening to it both ways, I've always chosen the digitized version. As I said before, we each choose where to compromise (until there's a digital interface and the digitizing step won't be needed).

BTW, my pre-pro also allows me to adjust the volume of the LFE channel separately from the volume of the derived bass from other channels. I've tried dialing down the LFE on SACD/DVD-A recordings; the result always sounds anemic compared to the flat setting. But then again, my system was set up and balanced with the LFE channel in mind. Sorry, my mistake. I have no experience with the ICBM so, unfortunately, I'll have to withdraw the only "100% agreement" I had with you.

Best,
Sanjay