This is topic Sound Advice in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=011179

---

Posted by Jonathan Bodge (Member # 4072) on 03-05-2012, 08:38 PM:
 
I need some sound advice, which could be interpreted 2 ways...story...local board of directors type stage theater (with concave ceiling dome to match)...old dolby processor (20 yrs.) JBL speakers behind screen. Reverse scan. Yamaha amps. Needs upgrading for sure. "Know it all" wants to replace behind screen JBLs with small QSC speakers up front of the screen. JBL's referred to as "old school". Reason for bringing speakers up front, so they can have dual use. Live and video/film. (not how I would design it.)
So, would a USL processor be good for both 35 and a top of the line blue ray? Are the Old School JBL's adequate for the digital realm? For a bi amped system in a 500 seat theater what amp power might be good? Thanks all..
 

---

Posted by Louis Bornwasser (Member # 3063) on 03-05-2012, 08:49 PM:
 
There are no new "rules" in audio, so old school, if adequate, will still be good. Certainly JBL had its share of dogs (need model number). Yamaha to me is questionable.

Is Dolby Digital a requirement? If so, use cp650, if not, perhaps an Ultra is enough.

As a general rule, the speakers in front of the screen is good for stage and behind the screen for film. That is why few, if any, systems are interconnected.

I would encourage a gentle upgrade of film and a seperate system for live. That way the "know-it-all" can win, too.

(btw: the film system will always sound more full, and more powerful.) Louis
 

---

Posted by Jack Theakston (Member # 4484) on 03-06-2012, 01:22 PM:
 
I agree with Louis. Set up two systems, and tell the tech to stick his nose in his own business.
 

---

Posted by Martin McCaffery (Member # 37) on 03-06-2012, 02:17 PM:
 
Louis and Jack are, of course, correct. Having watched other theatres deal with this over the years you should go to your stage tech guy and/or board with information and documentation about how stage sound is different than movie sound and each requires its own system to be done perfectly.
So many people think sound is sound (and movies are magic). Education is the key to getting your place equipped properly. And it is best to try to do it without internal warfare.
 

---

Posted by Louis Bornwasser (Member # 3063) on 03-06-2012, 09:04 PM:
 
Besides, proper film systems are always of higher quality; the entire reality MUST BE serviced through the audio. Stage systems only need be good enough for mikes.

The difference between: voices and A-bomb blasts. Louis
 

---

Posted by David Buckley (Member # 2600) on 03-07-2012, 03:13 AM:
 
If "small QSC speakers" will do the job of the live usage, then either the venue is quite small, or the live needs are quite limited, or both.

All things being equal, separate systems is the recommended approach. If nothing else, it prevents the attitudinal conflicts that can arise between movie sound people and live sound people, as demonstrated above. The two worlds have different requirements and value different priorities, and there are even some valid reasons why the approaches taken with cinema and live sound reinforcement are different.

Of course, if you need one system to deliver digital movie audio, live theatre and musicals, Metallica and dubstep (all at their intended volume, scope and scale), and to sound good with all these types of programme material, then you have a different set of problems to solve, and small box of any type wont be the answer
 

---

Posted by Scott Norwood (Member # 30) on 03-07-2012, 08:16 AM:
 
I'm not a sound expert, but I know what sounds good. The limiting factor with this type of venue is often the room, from what I have seen (heard). Large, old theatres can usually be made to sound good for live music and performances or film reproduction, but usually not both. A "live" (reverberant) room is preferred for live music, while a "dead" room is preferred for film. Rooms that were designed and built before the advent of talking pictures seem to be especially live.

I don't have a solution, but I can point to at least one example of a building where the overall sound quality was better with a single A4 behind the screen than with a full-blown modern sound system (installed for a rental and then removed). One change that did make a difference with the multichannel ssytem was increasing the center channel gain by 2-3 dB over the left and right stage channels. Dolby might not approve, but it worked.

As an audience member, the most important issue is dialogue intelligibility. The second most important issue for me is having the sound come from behind the screen, rather than from above it or from the sides. Get these right and everything else should be fine. Get them wrong and nothing else matters.

I agree with the comments that live sound people do not understand film sound (for the most part), although they do have some interesting tools now that might be useful for improving sound in problematic venues (in particular, DSP-based room correction and time alignment systems).
 

---

Posted by Louis Bornwasser (Member # 3063) on 03-07-2012, 12:28 PM:
 
Scott: besides increasing center level; it is also possible to "tailor the response" only on center. Set up normally on all three screen channels, add 4-5 db to center channel, then switch off all channels except center.

Using a film with dialog, and foreign accents, roll off the low bass, allow a rise in hf at 3-5k, and then roll off normally above. You may then have to raise the level again, a little.u
 

---

Posted by David Buckley (Member # 2600) on 03-07-2012, 03:42 PM:
 

quote: Scott Norwood

---

As an audience member, the most important issue is dialogue intelligibility

---

quote:

---

Louis Bornwasser said: Besides, proper film systems are always of higher quality; The difference between: voices and A-bomb blasts.

---

Sorry to jump in late on this...

Louis, with all due respect, this statement is not true by any stretch. "Proper" PA systems can easily match "proper" film systems. They both have to deal with the same 20 Hz to 20 kHz spectrum and dynamics. Reproducing dialog, "A-bomb blasts," or violins knows no favorites in terms of doing it with high quality.

In fact, I would bet the best PA technology (loudspeakers) I know of against the best cinema technology. The ultimate criterion for loudspeaker sound quality is transparency = lack of coloration = pristine transient response. This can be measured and is done so with the best PA equipment. I've never seen such data for cinema systems (except for the one I've been working with.) And no, the bode plots, impulse responses, waterfall plots, ETC's et al from typical commercial measurement systems don't have the adequate time and frequency resolutions to do this. RTA measurements are even further down the list.

I didn't detail this in my Yak "Who the Heck..." profile, but part of my career was some dozen years being in charge of the acoustic measurement labs, measurement data processing, and generating the product specifications for both Community Professional Loudspeakers and Eastern Acoustic Works (EAW). As such, I do have a little bit of knowledge about loudspeaker sound quality and measurements of same.

As to the primary question in this thread, a well-qualified audio consultant and separate PA and cinema systems are the right pieces of advice. Quality usually has a price. Filet mingnon costs more than a shank cut
 

---

Posted by Louis Bornwasser (Member # 3063) on 06-11-2012, 12:13 PM:
 
Usually the "budget" causes P.A. and film to want to be combined. Clearly your kind of P.A. is vastly superior to the 2-15's and a horn flying above the stage, which is what they want the movie to come out of (to save money.)

There are actually 2 problems:

Lack of quality in cheap P.A.

The speakers are not located in the right place for both uses. If amps are to be common, then the additional switching and eq's need for each eat up the money "saved." L:ouis
 

---

Posted by Chuck McGregor (Member # 6826) on 06-11-2012, 01:03 PM:
 

quote: Louis Bornwasser

---

Usually the "budget" causes P.A. and film to want to be combined.

---

Too bad there aren't really cheap projectors available to compliment such a budget-friendly approach (combined film/cinema audio). Then "they" could save even more money by having lousy sound AND a lousy image
 

---

Posted by Louis Bornwasser (Member # 3063) on 06-13-2012, 06:31 AM:
 
Trust me, there are (were). Louis
 

---

Posted by Jonathan Bodge (Member # 4072) on 09-11-2012, 08:36 PM:
 
Hi Guys, it's been a while since I visited this theatre. Louis, the main speakers are JBL 4647 and the Subs are 4645. Are these considered adequate for digital? And here is another question regarding this theatre. I was curious, keep in mind this was built in the 20's and opened as a vaudville. To the left and right of the stage about 15 feet high are, what I assumed large grates that had something to do with ventilation or organ pipes. I had a look behind and there is a box about 15 feet high and about 2 feet deep behind and up against the grate. Anyone know, in theatres built in the 20's what this space was? What the grates were? This is an incredible live venue because of the dome and the design. I assume these spaces were meant for something.
 

---

Posted by Tony Bandiera Jr (Member # 2365) on 09-12-2012, 12:37 PM:
 
The grates were for the pipes for a pipe organ, and the big box back there is an old "air chest" which helped store air to make the organ play.

Oh, and resist the temptation to place any speakers there, even for P.A. use.....pipe chambers are designed with very reflective acoustics to direct the sound from the pipes into the house.

quote: Chuck McGregor

---

In fact, I would bet the best PA technology (loudspeakers) I know of against the best cinema technology.

---

quote: Tony Bandiera Jr

---

Now a concert sound system (Sound Reinforcement System) IS designed for a wider frequency response and high dynamic range, BUT unlike a cinema sound system it is designed for extreme sound pressure levels (with a passing nod to accuracy) and, something you do NOT want in a cinema, broad, even coverage.

---

There was a time, not so long ago when that was true. The sound reinforcement industry has moved on a long way since then. You can have accuracy from a whisper to a roar. The issues about crossover region disruption are history, as is phase coherence.

Even coverage is now a setup choice, thanks to steerable systems and shading.

However, for a cinema, a cinema sound system will be a lot cheaper; this flexibility and capability does come at a price.
 

---

Posted by Chuck McGregor (Member # 6826) on 12-22-2012, 07:27 AM:
 
Sorry, been away from the forum for a while hence this delayed reply...

Tony Bandiera said:

>> P.A. (Public Address)systems are designed on the basis of projecting VOICES over a large area.

No argument if using "PA system" in a strict and rather archaic definition of that term. "Concert systems" are routinely referred to as PA systems, so we differ in definition.
Would you call systems for Broadway musicals or a houses of worships or a football stadiums "concert systems"? They are used for the same voices and music found in movies. There are many other types of audio systems other than "concert" or "cinema." In the broader definition any audio system that addresses the public is a "PA system." I used the term more in this sense rather than a voice-only system. So I'll use "concert system" to mean any non-cinema system used to reproduce full-range audio to an audience that substantially(!!) exceeds more than one person. (I do like "sound reinforcement" better but longer/harder to type )

Semantics aside....

quote: Tony Bandiera Jr

---

Now a concert sound system (Sound Reinforcement System) IS designed for a wider frequency response and high dynamic range, BUT unlike a cinema sound system it is designed for extreme sound pressure levels (with a passing nod to accuracy) and, something you do NOT want in a cinema, broad, even coverage. (I'll explain why in the next paragraph.)

An ideal cinema sound system must have accurate frequency response within the standard curve, must be capable of accurate reproduction from a whisper to a bomb blast (Concert sound rarely deals with a whisper) and, most importantly, has to have the RIGHT degree of coverage to reach the extreme sides of the auditorium, but MUST maintain the necessary channel separation illusion regardless of seating area. (Unlike concert sound where they don't always want or care about "stereo separation" but rather want the entire band to be audible clearly from ANY seat.)

I worked live sound for a few years during my career and can state that live sound and cinema sound are literally worlds apart in their requirements.

---

Actually the best concert system loudspeakers are most certainly designed with a intense focus (not a nod) to accuracy. I have intimate knowledge of this having spent the better part of 20 years working at four different pro loudspeaker manufacturers (variously from early 70s until retiring in 2007, though I still consult for one). Among other things I was in charge of the acoustic and electronic measurements at three of them.

For example, I have two smaller PA loudspeakers. That's what everyone calls them though they are hardly voice-only. They are also extremely accurate as it was ensured that they sounded exactly like these before they were released as a product:

Gelec 1038B

...only mine get about 6 dB louder (and didn't cost $8000+ each!)

Yes SOME concert systems are designed for extreme sound pressure levels. However, for comparable audience sizes the loudspeakers used usually don't substantially exceed the SPLs that a properly designed cinema system would provide for that same space. Those that do are more the exception, not the norm, such as larger scale touring systems. The reason? There's a dollar figure attached to SPL capability and normally people paying for non-cinema systems aren't made of money. Budgets are budgets.

Operating a concert system in "stereo" is generally frowned upon by the best practitioners. However, when multi-channels are required, properly designed multi-channel concert systems provide coverage to every seat from each loudspeaker, as should front channel cinemas loudspeakers. The goals are exactly the same: maintaining channel separation for optimum localization while providing the same performance from each loudspeaker to each seat. For a well-designed, multi-channel system you automatically get the former with the latter. That's the "right" coverage. "Accusing" concert systems of broad, even coverage doesn't square with SMPTE standards which require the same thing.

ANY pro audio system worth its salt these days, including concert systems, is capable of a dynamic range that can easily handle whispers and to bomb blasts. If it can't, it's either faulty, crappy, or improperly adjusted equipment. In this regard cinema systems have NO advantage.

As to the "standard curve" (X-Curve) -- This concept for system tuning was known and documented by the non-cinema audio folks long before it was "discovered" by those working with cinema. In fact, the same concept is routinely taken into account and used in concert system tuning. However, the "standard" used is derived from the specific acoustics of the venue, not a graph. (Ironically, actual room acoustics were the reason for the X-Curve in the first place.) There seems to have been some lip service in cinema-world being paid in this direction with the idea of layering room size onto the X-Curve.

The last thing that should be pointed out is that cinema loudspeakers normally use drivers, horns, and enclosures that are fundamentally the same as those same manufacturers use for their non-cinema loudspeakers. As well there is no magic in cinema electronics regarding dynamic range (whisper to bomb blast). Thus basic loudspeaker performance and electronic dynamic range have to be closely similar.

Tony, your experience with "sound reinforcement" is not the same as mine and seems mired in stereotyping systems for this purpose. I would largely agree with your comments as applied to many mediocre practitioners and system designs. However, my experience has been with state-of-the-art audio systems for all kinds of purposes including larger (and way loud) systems for stadium concerts. As such, I don't care about mediocre systems for any purpose and don't generalize my judgments on audio system capabilities or design on what such systems do or don't do.

Suffice it to say that in designing concert systems the basic requirements are the same as those of cinema audio systems. Among other things are channel separation (when needed), uniformity of coverage, large dynamic range, headroom, reliability, and, the most important one, reproduction accuracy. For the latter there is only one ideal goal and that can be largely achieved with the right measurement tools and the right signal processing (involving a combination of IIR and FIR filtering, not 1/3 octave EQ but that would be another long post to explain).

In short your assessments of "concert systems" seem based on run-of-the-mill, mediocre system designs and/or installation and/or operation rather than the state-of-the-art systems I've been involved with and to which I was referring.

I should also point out that I am actually giving a lot of benefit of the doubt in accepting (sound unheard and measurements unseen) to what is said in this forum about the stellar performance of cinema systems.

The bottom line is that I've know of no difference in the "ideal" technical requirements or goals that differ between full-range non-cinema systems and cinema systems in terms of the B-chain. The ones you cited are not differences.

The introduction to Chapter 5 of this book, lays out fundamental principles for designing audio systems. By correctly and fully applying these principles to what cinema presentation requires, using available "PA" technology, and not using THX, SMPTE, et al standards, the result would be an audio system meeting or exceeding all the requirements you cited as well as those standards. (Disclaimer: I authored the introduction.)

Architectural Acoustics Principles and Practice (2nd Edition)

Cheers
 

---

Posted by Manny Knowles (Member # 1171) on 12-27-2012, 12:36 AM:
 

quote: Chuck McGregor

---

I should also point out that I am actually giving a lot of benefit of the doubt in accepting (sound unheard and measurements unseen) to what is said in this forum about the stellar performance of cinema systems.

---

quote: Manny Knowles

---

Does this mean you've never heard a good-sounding cinema system?

---

Like I said, sound unheard and measurements unseen. I have only heard two cinema systems recently. In truth I have been only a very occasional movie theater goer over the years, my milieu being live sound. Note that this involved only some rock 'n roll. Think mostly orchestra, theater, opera, ballet, and the like.

Some years back I remember a large NYC cinema in the West Side 50s which was impressive. Contrarily I walked out of another NYC cinema around that same time with a refund. Intelligibility was...well...it wasn't.

Of the two cinema systems I've recently heard, one literally caused pain in my ears. I've listened to and evaluated countless audio systems of all types and quality levels over the years. I can't remember one causing actual real-time pain unless it was from being too loud. This wasn't the case.

The other system is the one I worked on. I know the loudspeakers are appropriate for the room in terms of pattern control, output capability, and they measure close to being anechoically transparent. The in-audience responses conform tightly to SMPTE specifications as to X-Curve and SPL uniformity. (I could post the measured data). The subjective opinions of others is that it sounds great. So I'll stick my neck out and say I think I've heard one good-sounding cinema system.

So, at best I'm 2 for 4 on good/bad cinemas that I recall, with any others being distinctly unmemorable in terms of the audio.

To be clear, I view a cinema audio system as just another variety of audio system. The details of how and why a cinema audio system is set up doesn't make it unique compared to other audio systems. In fact, I've found it was far more straight-forward to do the acoustical tuning of "my" cinema system than many of the systems with which I've dealt. Of particular note, I found the electronic gain structure is a piece of cake for cinema audio compared to non-cinema systems.

Only a couple of other cinemas that might be good to hear are an hour or more drive from here. There are also a couple of cineplexes around, but not much closer. I AM planning on going to one or more other cinemas at some point and promise to report. Aside from guessing, any known "good-sounding" cinemas in Maine?

For better or worse, that's my story...

"If bad sound were fatal, audio would be the leading cause of death." -- Don Davis
 

---

Posted by Tony Bandiera Jr (Member # 2365) on 12-27-2012, 01:08 PM:
 

quote: Chuck McGregor

---

The details of how and why a cinema audio system is set up doesn't make it unique compared to other audio systems.

---

quote:

---

quote: Chuck McGregor
The details of how and why a cinema audio system is set up doesn't make it unique compared to other audio systems.
Tony Said:
With all due respect Chuck that statement right there causes you to lose all credibility in this discussion. Cinema systems ARE unique compared to other systems, just as concert sound systems ARE unique compared to other systems, as are home screening room systems.

---

quote:

---

Cinema sound is mixed differently from sound for DVD's and home video, from sound for television shows, from sound for concerts, etc. To think otherwise shows a clear lack of understanding of the differing disciplines of audio.

[I hope you are not implying that I have a clear lack of such understanding or even a modicum of such lack.]

I have been in this industry for over 30 years now and one thing I will say is that there is always something new to learn.

[About 45 for me but 100% agree!]

There is NO one "correct" EQ curve or equipment lineup for ALL cinemas.

[Awww, sure there is for the latter. Just ask any manufacturer ]

The same held true for my time working concerts and live sound shows, every venue presented unique challenges (and if that wasn't bad enough try mixing stage monitors sometime...talk about a constantly changing environment..oy vey.)

[Been there, done that, don't like it, but do know some people who do serious and a serious amount of monitor work. However, I've been involved in the technology one way or another from the days of "What's a stage monitor?" to the "More ME in the monitors" of today ]

---

All that said, cinema systems ARE unique in one VERY important respect and that is the setup parameters are actually well-defined. There are only 4 things we deal with regarding sound: Direction, intensity, frequency, and time. Uniquely and compared to any other type of audio system I can think of, ALL of these parameters for how a system is to be set up are defined by cinema standards both for the sources (loudspeaker) and the receiver (listener).

My only "beef" with cinema audio is the lack of application of advanced technology available to better meet these standards, specifically concerning loudspeaker performance. As such, my personal thing is applying what I know about non-cinema audio technology (hardware, measurements, and psycho-acoustics) to the system for which I've become the "shepherd." Apart from that, and credible or not, my comments have largely been to note my understanding of the similarities between audio systems (such as the hardware Gordon McLeod correctly noted) that make such application possible.

PS To Manny: I did hear another good system a while ago in a big WB room (possibly re-recording Stage 4) where they were working on some big orchestral passages for "Batman Forever." Sounded fine, though I wasn't there to "evaluate" the sound.
 

---

Posted by Chuck McGregor (Member # 6826) on 12-31-2012, 12:51 AM:
 
To be clear, my 45 years "in the industry" I mentioned above meant the audio, not film industry.
 

---

Posted by Tony Bandiera Jr (Member # 2365) on 12-31-2012, 01:39 AM:
 
Chuck, thank you for the clarifications.

I did not mean to sound so harsh, but I can say I think I was channeling another thread here where we had a sound mixer who was rather um, wrong about a great many things.

One of my traits is to be direct and sometimes, especially in a forum environment, it comes off badly.

Rest assured your credibility to me is intact.

And thank you for the PM.

As for the monitor mixing, it was one of my great feelings of accomplishment when a show went well and the artists where happy with my work. I got the pleasure of doing mixes for, amongst others, Barbra Mandrell, Willie Nelson, and Cheap Trick. And this with only about a year of experience. Most were surprised to hear that, but one manager and house engineer told me I seemed to have the "knack" for it. I miss "my" Yamaha mixing board a lot...I told the boss after I left that if he ever wanted to sell that board I wanted first dibs on it. (Now what I was going to do with a 12x36 board was up for question.)
 

---

Posted by Chuck McGregor (Member # 6826) on 12-31-2012, 12:42 PM:
 
Tony,

Thanks for the kind reply. As to you being harsh (blunt)? I used to live on 43rd and 10th, NYC. You can do the math

quote: Tony Bandiera Jr

---

I think I was channeling another thread here where we had a sound mixer who was rather um, wrong about a great many things.

---

I can't believe there's a sound mixer who was wrong about a great many things.... (insert "isn't" in place of "was")

In truth there are few who are wrong, if at all, about very little...Robert Scoville comes to mind.

Having a knack for monitor work is something very few can claim. Like they say (reportedly) down under, good on ya.

Getting back to audio systems and "PA"/cinema audio:
Here's a link to a file about the theater I'm working on to give you an idea about how I approach things.

"My" Theater

The most important thing I start with for any "full fidelity" system is getting pristine anechoic performance from the loudspeakers. That means removing colorations. The problem is measuring them, identifying the sources, and correcting them.

The spectrogram used tells the tales. With the appropriate scaling and resolutions of the output spectrograph, visible deviations from the "perfect" loudspeaker correlate very will with audible coloration and vice versa. Calling that what it is, coloration = distortion. These distortions occur in both time and frequency domains and have little to do with traditional "distortion" data (harmonic, IM, et al). Measuring and identifying the sources of the distortions, understanding the mechanisms that cause them, and applying either physical or electronic correction is not a trivial task. Also identifying those that cannot be corrected is just as non-trivial.

The fact a loudspeaker has flat response gives one at best a tiny clue as to the "sound" of a loudspeaker, i.e. how much or little coloration it has. When you can subject one to the various analyises shown in the document I linked, a very different and less flattering picture about a loudspeaker's performance will usually appear.

I do not have hardware (as yet) to remove what colorations still remain, but I know the primary sources: reflections in the LF diaphragm, some horn honk, and reflections bouncing around between the phase plug and diaphragm in the HF driver that smear the upper HF transients. All else being equal, these particular colorations are both a major source of why loudspeakers "sound" different and, unfortunately, they are inherent in the design of these devices. You make one you get these anomalies. Only the magnitude varies with from design to design.

Fixing such things can require a combination of physical and (mostly) electronic solutions. The latter involves developing a single filter algorithm for the loudspeaker using a combination of IIR and FIR filters. The basis for this kind of algorithm was patented by my last boss, Dave Gunness. The patent goes into the more detail:

Patent

To me it should be self-evident that the direct sound performance of a loudspeaker (its anehchoic performance) is more important than any other factor (like the room's effects) in determining one's subjective notion of sound quality. The goal is transparency = lack of coloration.

Most all loudspeakers have colorations which is why we have discussions over which sounds "better" and why some loudspeakers sound seem to sound "better" on some source material than others. If all loudspeakers behaved as the proverbial "straight wire" there would be no such discussions. You want the input signal to arrive at the listen intact in time and frequency. Both are measurable and if not "intact" there will be colorations. As a result most all system tuning is a actually a process of doing the best as one can to make these distortions as "pleasing" as possible. Especially with only 1/3 octave equalizers, there is little else you can do. The colorations do not usually have 1/3 octave Qs, and 1/3 octave does nothing effective in the time domain, the main provenance of these colorations.

For "my" system, standard IIR DSP was used creatively to reduce or mask what colorations I could (I know a few tricks), but they are there and they can still be heard, albeit they are fairly subtle. Another thing I did was to time-align the HF and LF components to the temporal center of the seating so those in the front and rear row experience the least amount of offset.

As for how the system "sounds," one critique after the system was tuned as shown, was for a "Live at the Met" HD performance. A professor of music, life-long opera lover/performer/conductor/composer/teacher came up to me and said the sound was "stunning."

So there's a look at how I have applied some of my "PA" knowledge to a cinema system.

In case you're wondering, the L/C/R loudspeakers are the widely vilified (on this forum) EV TS940s. They were designed by Dave Gunness while he was an engineer at EV where he was also a primary design engineer for the HP series horns. As such, I have viewed ALL negative comments about this system as being the result of bad system tuning or faulty hardware. Tuned properly even with standard DSP (this cannot be done with 1/3 octave EQ or cinema processor crossovers) they provide excellent performance under stringent objective and subjective analysis.

I should note that the 1/3 octave responses in the linked document on the theater were taken at 1/48 octave resolution with SMAART. These spectrums were power averaged in SMAART and the averages smoothed to 1/3 octave with a proprietary audio measurement/analysis program called Rayleigh, of which the spectrogram is a part. Note that there was no EQ applied to the anechoic responses to get the X-Curves, but that's whole other discussion!

That's my story
 

---

Posted by Steve Guttag (Member # 268) on 12-31-2012, 05:33 PM:
 
Okay...I see that bait! I have heard the DH1A with and without EQ...it is a god awful piece of crap that EQ will only make worse. The TS940 only adds the tupperware to the dreadful piece of crap that is the EV TS940.

Your conclusions are wrong...it wasn't the EQ...it was the speaker.
 

---

Posted by Bajsic Bojan (Member # 4928) on 01-01-2013, 06:28 AM:
 

quote:

---

For "my" system, standard IIR DSP was used creatively to reduce or mask what colorations I could (I know a few tricks),...

Another thing I did was to time-align the HF and LF components to the temporal center of the seating so those in the front and rear row experience the least amount of offset.

...
Tuned properly even with standard DSP (this cannot be done with 1/3 octave EQ or cinema processor crossovers) they provide excellent performance under stringent objective and subjective analysis.

...
Note that there was no EQ applied to the anechoic responses to get the X-Curves, but that's whole other discussion!

---

Hello,
i've been really digging into this subject for the past month and your result sheet and info here is much much appreciated.

A couple of questions:
You had one MX8600 per screen channel? Did you do much (any) work on the subwoofer, apart from setting delay and levels? How well do those DSPs work with non-EAW speakers?

If one is spending cca 1500$ per DSP channel, would it not be sensible in the start to spend 1500$ more on a better speaker?

Do all speakers with passive crossovers just sound terrible and should one set them to biamp and use a separate crossover?

Do you think now, in the age of digital cinema, one should go with 8ch aes enabled dsp to handle basically the whole chain?

What kind of audio capture device do you use with 9 microphones for smaart? Is your reference a digital projector output or an external signal generator?

Thank you again for a wonderful insight.

Oh, and could you provide a basic RTA picture of the "before" state? I suspect it was the only one that didn't change as much as the others after the tweaks.
 

---

Posted by Chuck McGregor (Member # 6826) on 01-01-2013, 10:41 PM:
 
To Steve Guttag,

You’re right. I’m wrong. DH1A and TS940 system are crap. You Win!!!
_________________________

To Bajsi Bojan

It sounds like you want details, so I have provided all (probably too many) I think relevant concerning your questions as to what was/will be done and why to the system in question to get the desired results. This might avoid raising unanswered questions as the subject topics do get a bit complex. This also means I am sticking my neck way out in this crowd to all kinds of critiques/flak/grief because my ideas do not seem to me to be exactly main stream in the cinema industry and I am most certainly not a cinema industry professional!! So what do I know?

That said, what started as some simple replies to your questions ended up with me writing out most of my thinking about how to deal with the B-chain. As the post ended up MUCH longer than planned, I decided to put it in a PDF file rather than tie up Film-Tech bandwidth and risk the wrath of Brad

Also, those who care to read my ramblings can read them without having then clutter up the forum for others

Here is the link:
My answers to Bajsic Bojan's questions

Cheers
 

---

Posted by Bajsic Bojan (Member # 4928) on 01-02-2013, 01:50 PM:
 
First off,

i cannot thank you enough for one fo the most helpful, comprehensive and in-depth answers on the forums. I'm getting through it for the second time today, there is just a ton of really good info there.

Of course there are tons of questions that arise and thank you for responding to them in advance

Just a couple quick ones tho, where i probably wasn't very clear.

The 9 channel capture card question was, whether you used an audio interface for your computer to get simultaneous multichannel readings, as that is what many Smaart users do. As far as i know Smaart is one of a few available progs that can do seperate multichannel capture (without automixing the sources), as well as immediate comparisons between sources, etc. Your approach of doing the measurements one at a time then doing different types of 'summing' gives me some new things to think about (and more reading material ) And clears my confusion as to how to have 9 matched microphones each costing about a gazzilion $$

The 'RTA before curve' reference was just a hunch. The thing is that the RTA frequency response curve is one of the only things that most of the sound people who install equipment and 'tune' the systems look at and set as the only true reference. And even tho they look the same on most system, the results when playing back any reference material seem to be completely inconsistent.

Ok, now back to reading. I am sure I will be back with some questions later. Thank you again.
 

---