Why do so many automatic configuration systems set centers/rears to "large"? (1 Viewer)

[LanceJ]

Received two replies so far, one from Yamaha and one from a member of C.A.S.

Here's Yamaha's reply:

Lance,
If they are large and it chooses large then it is doing the right test. Normally if the woofers in the speakers are larger then 6 inches there considered large. The mic only goes by the sounds it detects. If you are running all large speakers you would need to try it at large then experiment with the surrounds at small. Sometimes it sounds better with
the surround backs set to small, but that is just an opinon. If you have any more questions please feel free to contact us at our toll free Customer Support line. 1-800-292-2982 Hours: Monday Thru Friday 8 AM to 4 PM Pacific time.

The C.A.S. member:

Hello Lance,

I recommend that you present this question on our website Forum. This will give you access to the more responses and idea’s. A large number of our members with years of experience participate in the forum regularly.

www.cinemaaudiosociety.com

Click on the forum link from there and ask away.

Thanks for your interest.

 

[LanceJ]

Is WSR available at places like Barnes & Noble, etc?

I am a bachelor for now, so it's easy to place five rather large speakers in my room (and they don't even match style-wise, a major no-no for certain people). But.....as much as I talk about such systems, I am not ignoring the fact most people truly cannot equip their living room with five 50+ pound speakers plus a sub - that's asking for the moon. This is partly why I mention dvd-audio so much since a dvd-audio's Dolby and/or DTS track can be bass managed and time aligned so more people can enjoy 5.1 tunes. While these aren't hi-res formats, IMO they can still sound very acceptable to many people.

As far as 5.1 music mixing standards: could he mean something to do with what we're talking about i.e. bass management? Becuase if he means artistic standards, then yea, that's not good. The only standard I, and I think one that many others would accept, is that if someone makes a 5.1 mix produced by running the stereo master through a DSP box, then this should be indicated on the label somewhere. Many of the big name mixers have already recommended this in a paper on the Grammy.com site entitled "Recommendations for Surround Sound Production". There's some good info in there for home playback systems too.

I do see the attraction of the one-cable connection, but that would mean selling a receiver with the needed DACs & b.m. systems built in. And seeing as how unpopular 5.1 music is, I'm not sure how many companies would do that, especially in their mid to entry-level models.

 

[Brian L]

WSR is available on the newsstand.

The panel was there to discuss the paper that you mentioned. Gary's interest is that there seems to be no standard for any aspect of MC music production. As such, there can be no standard for home playback of that same music.

The discussion touched on bass management (some members said they ALWAYS use a sub channel when mixing, some never!). Some said that they check their mixes on large speakers w/o sub, some do check with a typical 5.1 system.

Another of Gary's touchstones is phantom imaging between any two channels of a system. Elliott Scheiner really took him to task on that, stating that it is not possible to get a phantom image between the two speakers unless you are facing that pair. Els said that he mixes for two hemispheres; across the front, and across the back.

There was also huge debate about the fact that HD DVD and BR can support 8 channels. Almost to a man the guys on the panel said non-sense; 5.1 is THE standard they use and will continue to use.

Anyway, its an interesting read.

Brian

 

[Brian L]

Double Post.

 

[LanceJ]

Here's the response from THX (I'm not totally sure about email vs. public forum etiquette, so for now I'm not going to print the author's name; but just PM me if someone wants to know):

"Dear Mr. J....:

THX has been working with pretty much everybody in the home theater business for 15 years now and is the author of the “all speakers small, sub yes, 80Hz x-over recommendation”. While there is nothing sacred about our recommendation, for a long list of technical reasons it has more than stood the test of time as the best choice most of the time. THX goal for home theater is a system in which the sound is right at all the seats, and the directors story can be presented exactly as it was created in the studio. With your level of expertise (and since you have no way of actually knowing what the director heard) I suggest you get out a variety of your favorite program material and listen to the different setups. The only thing that really counts is that it works for you.

Some reasons why “all speakers small, sub yes, 80Hz x-over” is a good idea:

80Hz is two standard deviations below 120Hz which is the lowest frequency that is clearly localizable and when combined with a 24dB/Octave low pass makes the subs essentially un-localizable.

Redirecting the bass from all channels to the sub(s). makes control of the rooms bass modes much easier resulting in better (but not necessarily louder) bass at all the seats.

See. http://www.harman.com/wp/index.jsp?articleId=1003

Redirecting the bass makes smaller speakers possible which are then easier to place properly relative to the picture, the room and the seats.

Redirecting the bass to the sub allows the speakers to play louder before distorting. The THX target is 105dB at the listener, as mixed in the studio.

It’s logical to cross some speakers at 100Hz or even 120Hz. Going lower gives up important room mode control and going higher makes harder to get a seamless crossover.

Have fun.

***************,
Senior Fellow
Director, Education
THX Ltd.

I thought this line was interesting: "....makes control of the rooms bass modes much easier resulting in better (but not necessarily louder) bass at all the seats".

Got another message from a different C.A.S. member - he is involved with a project now but he said he will try to answer directly when finished, so until then he provided a link to check out:

UPDATED Room Calibration for Film and TV Post

 

[LanceJ]

(I have to read that article!) Even for me, five speakers is my limit for a living/bed room.

But music surround, IMO anyway, just doesn't need two extra channels. And anyway, in most rooms it's already difficult enough to properly place five speakers, much less seven(!).

If labels start pushing for eight channel surround ANYTHING, with the state of the audio market nowadays, I think they are asking for trouble and a lot of "what the hells" from movie and music fans. :frowning:

 

[Blaine_M]

Ok, I've tried to read through all of this, being the non-techincal person that I am....I am now confused. I have a pair of GR-Research AV-3 speakers that will hit 40hz. I have a GR Research AV-3s center that hits 80 hz. I have a Marantz SR-5400 reciever and an SVS PB-10ISD with no crossover on the amp. I currently have the crossover point set to 80hz on the marantz, I have the fronts set to large and the center set to small. I have the bass mix option that Marantz has set to send the low frequencies to both the mains and the sub when listening to music. From reading what has been posted....should I set my fronts to small instead of large?

 

[Brian L]

I would say set 'em small, because I am an advocate of sat/sub systems (for the various reasons cited previously), but it is impossible to say what combo will give the best result in your room.

Without some measurements to help set things optimally, you will need to let your ears be your guide.

Brian

 

[Bobby T]

try it both ways and determine which way sounds the best

 

[LanceJ]

Pioneer replied yesterday:

Thanks for contacting Pioneer Electronics, Inc.

Based on your e-mail request, we feel that we can be of better
assistance if you contact our Product Support line.

Please contact us at (800)421-1404 for further assistance.

Thank You,

****************
Customer Service Representative

:frowning:

I was hoping for a technician-type of person to reply.

Well, so far no full explanation of why these automatic systems work like they do.


I keep see-sawing back & forth on this type of advice. On the one hand I'm usually a person that believes in sonic accuracy but to do that in this situation requires the purchase of measuring equipment & software that is rather complicated to use (and IIRC in the case of that RadShak SPL meter, it requires correction figures to make sense of its INaccurate readings). On the other hand.....if it does already sound good, why not just keep the system configured that way? Of course I'm assuming everyone has heard live music so as to have a reference point for that "sounds good" judgement. But what about movies and all their various sound effects, many artifically generated - how would we know what's "real" i.e. what the director wanted us to hear? Now we're back to the measuring thing again. ::sigh::

btw, I'm going be brutally honest here: the thought of telling an Average Joe person - i.e. not an HT hobbyist - to run out and buy a meter and associated software makes me giggle. After selling HT gear and just generally talking about it to those people for years before/after that, I am betting 99.9% of them will absolutely not do that. The main reason I'm bringing this up is I've seen some people bluntly tell others that if they don't calibrate their HT system with a meter/software, they may as well not use the system at all. I'm sorry, but for me that is really narrow-minded thinking, and is going to be a major turnoff for most people. That's the same as telling the owner of a new Corvette that unless the engine is pulled, blueprinted & balanced, he's wasting his time driving the car.

Preachy part: We've got deserted audio departments in every store I check out, from Wal-Mart to Best Buy to hi-end stores with B&W Diamond series speakers, so IMO one might want to be careful telling others they have to measure X & Y or they have to buy such-n-such piece of HT gear, or else all their movies will sound like crud.

Because the thought of a TV monitor's 5" full-range speakers or an iPod being the epitome of high-fidelity gives me the shakes. :frowning:

 

[LanceJ]

Got another reply from THX (when I thanked them I also included some thoughts about 5.1 music reproduction):

Yes indeed.

I think you're right regarding bass management and the music industry. No one we've worked with seems to understand the fundamental science governing the behavior of bass in small rooms. They've been working in
heavily over treated rooms for much to long which completely hides sound the ordinary consumers will hear. That and mixing at levels that few people with neighbors or wives will tolerate. Pity, since 5.1 music can
be quite cool. We have sat in rooms with music heavyweights and they just fight like cats and dogs defending their own, often extremely narrow, pet methods. I think you'll find the paper I referred to very interesting and It's based on good science.

BTW, the auto setup and calibration features that are becoming common can all be relied on to make some very strange even scary choices. As Ronnie used to say "trust but verify".

Here's our very abbreviated take on it. Even for a super system, you only need get the basics right and the rest will sound as good as it will.

1. Speakers selected and aimed to cover the audience with accurate sound.

2. Speakers with smooth off axis response, free from unwanted resonance.

3. Speakers and amps that will play as loud as you want in your room.

4. Multiple subs placed for maximum control room modes. (Yes, this is basic)

5. Four surround speakers, two to the side and two behind.

6. Quality EQ done by a home theater pro that actually knows what they are doing.

7. The quietest, best isolated room possible.

8. Room reflections that match the timbre of the speakers direct energy.

9. Room reflections that decay at a moderate rate.

10. Simple to use properly programmed remote.

When using good quality gear the most audible are, 1,2,4,7 and 10 (Yes, 10)

The Above 2kHz speaker quality dominates, below 200Hz the room dominates, from 200-2k the knowledgeable home theater pro dominates.

Aint it great?.

***************
Senior Fellow
Director, Education
THX Ltd.

Now we're getting somewhere.

So it seems like at least the EQ portion of the auto systems is defintely valuable.

 

[Kevin C Brown]

If you want to *know*, then you have to measure. If a person is happy just with what their ears are telling them, which obviously can be false by the way, then that is a valid option too.

For example, it's common knowledge among speaker-type people, that a valley or a dip in a speaker's response is much more benign to the human ear than a peak. (It's easier to tell what's there that's not supposed to be there, than the lack of info.) ... And that's exactly what happens if you try to set the crossover freq too low for a speaker that doesn't go as low as you think. A person might think, hey, this sounds pretty good, never knowing that it could sound better.


And, have you ever tried to balance levels by ear? I was surprised by how far off I was. The different physical locations of the speakers really messes with how loud they are perceived.

And a good analogy is ISF calibration of a display. Do they do it by "eye"? Certainly not. They bring measurement gear with them to get the absolute best picture. Not just according to someone's perception.

 

[LanceJ]

At the risk of sounding wishy-washy I agree with both parts of this.

But I guess what I'm confused about is all these past decades audio hobbyists have been satisfied with using their ears to set up systems. Obviously I'm talking about stereo, which only has two channels to work with but this can definitely also have its share of sonic anomalies.

Now all of a sudden we're being told to measure everything or else we're screwed (this goes for displays also). As someone whose career field is the teaching of science, I fully understand the desire to find the truth, but I guess I'm becoming dismayed at the thought of one my favorite hobbies becoming so complicated and time consuming that only the most dedicated and/or financially-able people can share in it. As I've mentioned here before, and I'm not saying this to pick on anybody here, the importance of setting up a home theater system shouldn't be equated to launching a Mars orbiter i.e. if something is a little bit off, nothing is going to explode & society isn't going to crumble. That being said, my geeky side has had me thinking about looking for a used Infinity R.A.B.O.S. subwoofer because of the favorable reports of that system's effectiveness i.e. taming those peaks (the worst one, anyway) that Kevin spoke of. I'm not a bass head or anything, but good balanced bass is nice to hear, and this seems like a reasonable way to get close to that goal and it's not just for multichannel systems either (no I don't work for Infinity).

I'm edging into philosophy territory here, but I've noticed this trend in other areas too, where people are told to be ultra-precise with things that really don't HAVE to be looked at that way to achieve the desired result. I wonder if that is one of the reasons we see so many stressed out people running to the pharmacy for Lunesta and taking up yoga, all just to get through an average work day.

Anyway..............

 

[LanceJ]

You're not the only one, which is why I started this thread.

But for now I would take Brian's advice and set up your system the way it sounds best, as long as nothing could get physically damaged (in other words don't set a front main speaker with a 3.5" woofer to "large"). The all-small concept seems to be a solid way to go for the majority of systems and when the owner doesn't feel like experimenting.

 

[LanceJ]

Accuracy vs. musicality discussion

 

[JeremyErwin]

When stereo recordings first came out (for the home), a number of demonstration records came out, supposedly to "show off" what a stereo setup could do.

These records weren't subtle. One such recording featured a train leaving one speaker and entering the next. By God. It's in Stereo!.
Perhaps similar in spirit were the so-called Phase4 Stereo recordings. I have not heard them, but I recall reading a scathing review of a HMS Pinafore recording.


Not having heard the results, though, I can't comment further.

A properly mastered stereo recording, in a properly set up room, will sound three dimensional. No violins in right, oboes in the left. but rather a cohesive mix floating in space between the speakers. A proper setup is hard to do, and if you're not careful, expensive. Some people line up their speakers millimeter by millimeter, trying for that absolutely perfect soundstage. (I've heard my professor's Martin Logans-- it is very much possible, though, at least for the moment, financially improbable...)

With movies, we're back to the effects. Bullets whiz past. Dialogue comes from the screen. And if there's any doubt in your mind that this is supposed to be a three dimensional audio simulation, you can always look at the screen.

But with DVD-Audio, the screen can't serve as the crutch. The speakers have to do all the work. There's no image to remind you that there are actually two bass instruments combining in interesting ways. There's nothing to remind one of the fact that one is in between two string orchestras, one in the front and one in the back. Nor is there any visual cue that one set of instruments is playing in a choir loft, and one set in the nave.

No, the first requires large speakers. the second requires surrounds comparable to the fronts and the third requires specialist height channels. Unfortunately, placing five (or six) large speakers requires a great deal of skill, and the optimization routines are far more difficult than getting out the micrometers and precisely positioning one stereo pair. (Phase differences...) It's a lot easier if you relegate the low bass to a subwoofer, but that sort of destroys any chance of experiencing stereo bass. The equations, the guidelines all seem so difficult. It would be nice to know what the studios are doing, so that one has at least a starting point from which to tweak.

 

[Kevin C Brown]

Lance- But that's the whole point! Because it's a hobby, you can get as deep as you want, or as shallow as you want, to each person's level of interest. That's why some people measure, and some don't. Why some people still listen to lp, and others are perfectly happy with an iPod. I read Stereophile for different reasons, but I think it's the dude Art Dudley, who very strongly puts forth that it's about the music. The equipment is just a means to end.

I feel sorry for the "audio snobs" who are *constantly* upgrading because they are always finding fault with *some* different piece of gear they own. In other words, they can't enjoy their systems because there's always something wrong with it somewhere.

The equipment is there to enjoy the source. That's it. Although a lot of us certainly do find some of the technical details interesting.

 

[LanceJ]

I do too (honestly), and I try to read a good sampling of rather dry audio sites & white papers to keep up with what is happening out there - I just don't *act* on all of that information.

I know that with hobbies there are a huge range of interest levels; its just seems that more and more of the technology end of things is interfering with the enjoyment of whatever it is the technology is supposed to be helping us to enjoy.....in my opinion of course.

I knew I was going to stir up some trouble with my last (long) post above, but I figured it would help others figure out where I'm coming from. If anyone hadn't noticed already, I'm a big fan of Henry Kloss and the things he has designed and sold: no non-sense gear that only includes the things needed for audibly good sound.

 

[Brian L]

I would tend to disagree with that premise, Jeremy.

It has been argued and proven that bass below a certain frequency is omni-directional, but there are overtones and such that will give directionality to most instruments that extend down into the bass. And it is those overtones and transients that give the sense of "stereo" bass.

And if done right (and I will agree that this is not easy to do it right), a sub/sat system will produce stereo bass (if there is such a thing) just as well as two full range speakers.

I will cite as evidence my 2CH rig. Note, everyone is welcome to come over and have a listen!

It consists of NHT Absolute Zero' s and a Klipsch SW8 II crossed over at 100 hertz. The sub sits dead nuts between the two AZ's. I sit precisely at the top of the triangle. If you play the channel ID and phasing tracks from Stereophile's Engineer's Choice CD (short runs played on a Fender Bass), you will SWEAR that that Fender is coming from those tiny little AZ's.

On music, Drum whacks panned hard L or R sound like they are coming from the L or R (and of course, stuff panned between sound like they are coming from all points in between). But again, the sense of location is not due to the fundamental frequencies; its the overtones and transients that make it so.

Now, I would concede that in this system, a contributor is that the sub is on the same horizontal plane as the sats. Were it NOT in that location, then I would perhaps need to cross it over a bit lower. But the key is "when done right".

Brian

 

[Bobby T]

I sort of fall into this category with a small exception. I thoroughly enjoy my system. But I also enjoy doing upgrades, including the research end. I don't do it because of flaws I find in my system. But more due to improvements that can be made, even subtle ones. For example I'm currently looking into replacing my 15" Titanic sub with a SVS pc ultra. The Titanic is awesome. The SVS will extend lower on movies without giving up the musicality of the titanic.

Back to the main topic. In my system, listed somewhere previously, I've recently been running fronts, center, and back surrounds as large. Side surrounds as small, crossover at 60, and bass out fronts+sub. This is the best my system has sounded. I arrived here starting with all small, crossover at 80, bass to sub. I didn't even run the auto cal, just went with the standard configuration+the SPL meter. I then went with auto setup, meters, and tools to get it technically set up. My auto cal set it all speakers large, crossover at 60, bass out to sub. Then lastly by ear to get it perfect. My ears tell me it sounds better in the current configuration than how the auto setup originally left it. The current configuration is slightly different, but the differences are much better. My experience in this hobby has taught me that you need both tools and ears to get it just right.