Site created 12/15/97.
page created: 2/8/01
Chat Transcript: Dolby
on Home Theater Forum
The following is a
complete transcript of the on-line chat with with Brent Butterworth
of Dolby Labs, held on Tuesday, February 6th on
Home Theater Forum. Thanks to Ron Epstein and the staff the
HTF for all their hard work, and for providing the transcript for
all to read. Enjoy!
Home Theater Forum
Subject: DOLBY LABS - Brent Butterworth chat
Date: February 6, 2001
[RonEpstein] Good Evening everyone. I'd like to thank all of you for
joining us here tonight as we welcome Brent Butterwoth from Dolby
Labs. Hello Brent!
[RonEpstein] Brent, could you tell us what you do for Dolby Labs and
how long you have been there?
[Brent_Butterworth] I'm the Director of Consumer Technology
Marketing for Dolby Laboratories. My job is to educate the industry
and the public about Dolby technologies as applied to consumer
electronics. I've been here since September of 2000.
[RonEpstein] We appreciate you offer to talk to the membership here.
I am going to open the floor to questions
[RonEpstein] Okay, NathanPatrick is first up....
[NathanPatrick] I was just wondering when we can expect Dolby Pro
Logic II available in consumer products.
[Brent_Butterworth] Meridian might be shipping it already as an
upgrade to a couple of their existing processors. TAG McLaren should
be ready to go with an upgrade quite soon. The first mainstream PLII
products you'll see will probably be three Kenwood receivers
shipping in April. First, Pro Logic II is a new surround sound
processing scheme that provides five full-bandwidth channels from
any source: stereo CDs, VHS tapes, TV shows, MP3 files, 8-track
tapes, whatever. Basically, it gives any source much of the same
quality you expect from a discrete 5.1-channel source. For movie
theaters, the next big move will be digital cinema. Digital cinema
involves broadcasting movies to theaters over satellite, then
displaying them on a large-venue video projector. All of the
proposed digital cinema systems are 12-channel formats. The
10.2-channel format is one proposed by Tom Holman (of THX fame), but
not yet implemented in a real consumer or professional format. But
10.2 could fit into the proposed digital cinema systems, so....
[Scott_DeToffol] Is there any work being done by Dolby Labs, chip
manufacturers, or equipment makers to help with investment
protection. As you know, this is an expensive hobby. Can Dolby work
with manufactures to allow for software upgrades of devices when new
surround processing technologies are released?
[Brent_Butterworth] That is definitely a major concern of ours. How
a manufacturer designs its products is really up to them -- it's
sort of the "Dolby way" to stick with the audio quality
and let the licensees do their own thing otherwise (although we do
make suggestions). I think it'd be nice for more manufacturers to
make their products upgradeable, and we're already seeing a lot more
of that now. How this applies to what Dolby's doing now is that we
take this issue into consideration when we're considering new
technologies. We don't want to do something that's going to obsolete
everyone's existing gear, or stick our licensees with large
inventories of unsellable product.
[Heinz_W] What will it take to sell the average consumer on surround
sound, if anything?
[Brent_Butterworth] GOOD DEMOS!!!!
[Brent_Butterworth] But then there's that issue of getting them into
the stores in the first place. It IS improving -- when I was at
Video magazine in the early days of home theater, it was tough to
get people interested in this stuff. But DVD has helped
tremendously, as you can imagine.
[Bjoern_Roy] Whats your opinion on DTS ES 6.1 Discrete? Since it is
backward compatible with 5.1, would you consider it to be really
[Brent_Butterworth] Depends on what you call really discrete.
[Bjoern_Roy] if it had any back surround effects in it that would be
a superset of what is possible with a matrixed system, it wouldn't
be able to be dematrixed on a DTS ES system.
[Brent_Butterworth] Technically, it's not really discrete, since the
Cs signal is carried on Ls and Rs. But mathematically, it all
subtracts just fine, so the end result could be called discrete.
Whether or not discrete ES is what the director intended you to hear
is really an issue for the director. So far, the stuff has been
remixed for ES Discrete, since there's very little facility for
6.1-track masters. However, that could change. The real issue, I
think, is how readily consumers will accept a sixth and seventh
speaker into their homes. It's an issue with EX, too.
[Bjoern_Roy] Does it really subtract just fine? Because the
subtraction is done after the 3 channels are compressed. The
european MPEG2 Audio system had a similar problem.
[Brent_Butterworth] There are technical problems with applying their
subtractive matrix technique to lossy-coded signals. However, since
it's just taking place in one channel (Cs), not three (C, Ls, Rs) as
with MPEG, it's probably less of a problem.
[ChrisCaine] Why is it that some DD movies sound so good in the
cinema but lacking on DVD, eg. Deep Blue Sea? And would you include
your trailers like DTS does? I really liked the FIGHT CLUB track.
[Brent_Butterworth] You have to remember that you heard the two on
totally different systems, in different rooms. Also, the DVD sound
is actually better than the films sound. Most of the DVDs are at 448
kbps, while the films are at 320 kbps. We get that question about
the trailers all the time. But that's a different division, so I
really don't know. I will mention it to them.
[ChrisCaine] I understand that, but generally speaking, quite a few
people have noticed a general 'down' sound on DVD.
[Brent_Butterworth] Problem is, your acoustic memory just isn't long
enough to do a real comparison. They could just be responding to the
environment of the theater vs. the home environment. I've heard the
difference between Dolby Digital at lower and higher rates, and 448
definitely sounds better than 320.
[corbinstirn] I work as a salesman at a electronics
store.............I was wondering why there are not any demo DVDs
available for consumers to watch. I bought one myself and brought it
in....................customers really enjoyed it.
[Brent_Butterworth] It's hard for us to get the rights to all the
material -- DTS does demo discs more easily 'cause they're
part-owned by Universal. But we'd like to do that. Keep an eye out.
[corbinstirn] considering I still have a lot of people that are not
aware of the differences between DD and Pro-logic until they hear
[DanR] Brent, given Dolby's close relationship with Lucasfilm, will
you guys be involved in helping with the audio side of Lucasfilm's
rumored DVD releases (i.e. helping to create 5.1 EX DVD soundtracks
to Indy Jones and the 4 SW movies)?
[Brent_Butterworth] Probably. We have a whole bunch of guys whose
job is to work as consultants on film sound production. I know one
of them pretty well, and he's up at Skywalker a lot.
[Craig_Dobis] has dolby labs ever thought of having a demo dvd of
film clips to demo home systems and setup speakers. i see already
[Brent_Butterworth] I have an answer, actually. For various
reasons, Dolby doesn't really like to do discs with lots of noises
on them, but we are currently working with a record label to do a
DVD-A setup and test disc for consumers.
[Bjoern_Roy] We have a consensus here at the HTF that the sonical
differences between DD and DTS track on a DVD that feature both, is
because a different MIX is used, or SPECIAL ATTENTION was taken.
Could you explain what that means? You're correct. There are some
sonic differences, but they are quite small. We've demoed the two
for various press and licensees, comparing DD and DTS at all data
rates used for DVD, and everyone has agreed that the differences are
very tiny or nonexistent. Are different mixes actually equalized
differently, are different filters used for up- or downsampling,
what can make one mix SMOOTHER than another? Often a different
master is used for the DTS track. But we don't know what's done to
them. We can only speculate. However....there are other reasons why
the two sound different. The bass management, for one, is very
different. DTS didn't have a bass management spec until 1999, if
memory serves, so some products defeat bass managment when they go
into DTS. Also, the DTS encoders have a fixed LP filter for the LFE
track; it measures -3 dB at 90 Hz. The Dolby filter measures - 3 dB
at 120 Hz -- and it can be (and sometimes is) defeated entirely.
[Andy-G] what format do you believe mono movies should be encoded in
on DVD? 2.0 or 1.0? Does it realy make any sense to double the same
sound track in two seperate channels? Also, do you see the inclusion
of both DD and DTS soundtracks as a threat to common household
[Brent_Butterworth] Common household acceptance of one of the two
formats, or the DVD format in general?
[Andy-G] person hears both formats and finds that he or she cannot
tell the difference and is no longer truly interested. In further
purchase because she thinks that her VHS sounds "just fine"
[Brent_Butterworth] First, I think it's best to do mono stuff in
2.0, but that's a matter of opinion. The soundfield seems pretty
tiny to me coming just from a center speaker atop the TV. If they
can't tell the difference between Dolby Digital and DTS, that's
really a problem for DTS. Dolby Digital (or PCM) is mandated for the
format, so we're going to be there regardless. And acceptance of the
DVD format is going better than even its biggest boosters dared
[Vince_Maskeeper] okay, mine is slightly long, so you'll have to
forgive me: There has been a lot of discussion, both on the HTF and
beyond about Dolby Digital on Laserdisc as the medium vs. Dolby
Digital on DVD as the medium. It seems that most people who have
done a-b comparisons have perferred the DD sound on laser (me
included). Do you have any insight into what a possibly diffences
could exist (I would have assume in the digital realm bits is bits).
I just found it puzzling: even if they come from different source
masters (which I assume), 99% of the time people prefer the LD. That
seems like more than coincidence. You'd figure it would be closer to
50-50% if it were just a matter of source tapes.. I know you're
marketing end, not maybe as technical, but wondered if you had any
thoughts on this LD is superior for Dolby Digital idea?
[Brent_Butterworth] LDs are encoded at 384 kbps, and DVDs are mostly
at 448 nowadays. With Dolby Digital, DTS, and MLP, you've talking
packetized data. It's not really susceptible to the effect of
jitter. It is possibly the effect of different masters. Oops, I
forgot -- there are some minor differences in DD encoding in the RF
mode, which is used for LDs. I doubt that they would make the sound
better, and having heard the difference between 384 and 448, I think
there's no way a 448 DVD wouldn't sound at least as good as the LD.
[RonEastman] Hi Brent. Dolby's paper on DTS reports the superiority
of the higher bitrate DD versus the lower bitrate DD mastering.
Since Dolby's own studies show an advantage, what do your
consultants do to encourage studios to use the higher bitrate?
[Brent_Butterworth] So far, they've just encouraged studios to use
the higher bit rate! But we have started bringing in film sound guys
for comparisons of all these formats in state-of-the-art 5.1
mastering studios. I think that'll help when they hear the
difference in such a critical environment.
[AdamBarratt] Will PLII processors also include Pro logic processing
for those who wish to listen to Dolby Surround soundtracks as they
were heard in theatres? Or is Pro Logic headed the way of the Dodo?
[Brent_Butterworth] That's optional, although I think most of the
processors will include it. PLII has an emulation mode that uses the
PLII logic, but sums the surrounds and HP filters them at 7 kHz. Or
the manufacturers can use the original Pro Logic. But yeah, I think
that in a year, except in real low-end product, PLII will replace
original PL. Did I mention that PLII was developed by Jim Fosgate,
who is like the Obi Wan Kenobe of matrix decoding? I should also
point out...that it's unlikely there will be analog PLII chips,
whereas there are plenty of very affordable analog PL chips, so PL
may be around in low-end product for quite some time to come.
[ParkerClack] Some of our members have actually set down with Jim
Fosgate and seen and heard his tube version of PLII.
[Brent_Butterworth] lucky you! I've never heard it
[NickSo] this also is reagarding DPL2: When do you expect DPL2 to
become as popular as say, DTS? and how much/which price range will
it be in? Like maybe in a processor?
[Brent_Butterworth] Kenwood will be shipping a $300 PLII receiver
(with DD and DTS) in April. I think PLII will become more popular
than DTS very quickly. It has a lot more applications -- car audio,
for example -- and it's more useful overall. It works with all your
old software, so you have literally millions of things you can
listen to with it.
[RicP] Hi Brent, I was wondering what your opinion was on adding
more channels to the current 5.1 setup. With both Dolby and DTS it
seems pushing towards more channels, do you think that more channels
will be accepted by the mainstream consumer? And where do you think
it will stop? Thanks!
[Brent_Butterworth] Oh, MAN! I wish I knew! Obviously, I have to
doubt that 6.1 will ever be as big as 5.1. In a lot of homes, it's
hard enough to get two surround speakers positioned properly, much
less three or four. Where will it stop? I just don't know. If we go
much further, it's hard to imagine many consumers installing the
systems themselves. If there's ever a 10.2 format, I think it's
likely to be found only in very high-end installations, and most
consumers will downmix it to 5.1.
[RicP] Thanks, I'd love to have a 10.1 system, but will most
consumers actually spend that much! :)
[Steven_Simon] What are your feelings as far as DVD Audio, SACD, and
5.1 channel music?? Where is it heading?? And where does Dolby lie
in that mix, being an Audio Purist, I prefer 2 Channle Stereo,
[Brent_Butterworth] I think it rocks! I have been playing around
with DVD-A and have really enjoyed many of the mixes and the extras.
The ELP disc was a really emotional experience for me -- a band I'd
written off more than 20 years ago, but was suddenly reminded why I
used to own all their albums and went to see them live. I hope it's
heading for mass-market acceptance. I think DVD-A players will
become very affordable very fast, and that will help. And of course,
the record industry will eventually get real good at 5.1 mixing.
[ParkerClack] Was that the Brain Salad Surgery ELP that you heard?
Also, have your heard PLII in action on a two channel CD and what
effect does it have on the overall sound?
[Brent_Butterworth] Yes, Brain Salad Surgery. The mix of "Still...You
Turn Me On" is a must-hear. PLII works great on 2-channel CDs.
It is nothing like original PL in that application. It basically
makes the whole thing sound like a 5.1 mix.
[ParkerClack] I'll bet Still.......is killer. I saw them live too.
You can never forget setting Keith Emerson flying around in the air
playing his grand. :) Thanks.
[Brent_Butterworth] With PLII, you get lots of backing vocals,
ambience, and some instruments in the back, but the front soundstage
stays really solid.
[BarryLieberman] Brent, as someone who has been involved in many
facets of the ht/home audio industry, how would you counsel recent
college grads anxious to become immersed in the business end of it?
[Brent_Butterworth] You mean engineering grads or otherwise?
[BarryLieberman] More along the lines of those aspiring to get
involved in the marketing/sales side.
[Brent_Butterworth] First, go get a job at a local dealer. That
gives you real-world experience that will help you a lot. If you
have a marketing degree (or something similar), it would be a lot
easier if you lived in the L.A. or N.J. areas -- that's where most
of the manufacturers are.
[BarryLieberman] Specifically, I had an interview with David
Birch-Jones of Denon in December, but was passed over for someone
with previous experience...I was curious as to whether getting my
CEDIA license would help
[Brent_Butterworth] It might help. Wouldn't hurt. And demand for
installers is very high. [Brent_Butterworth] done
[Jason_Naper] Just wanted to thank our guest and I'm wondering what
the difference is between Dolby and DTS.
[Brent_Butterworth] I could do -- and have done -- entire papers on
[Jason_Naper] Is everything moving to the DTS side?
[Brent_Butterworth] One thing I can say is that Dolby Digital is
much more broadly accepted -- it's in the DVD standard,and in the
U.S. (and many worldwide) DTV standards. No, I think even DTS would
admit that Dolby Digital will remain the primary format for
multichannel audio compression. It's much, much bigger than DTS.
They have positioned themselves as a specialty company, not as a
[Bjoern_Roy] A lot of people, even on this forum, let alone the
average viewer, don't really understand Dialog Normalization. Since
most DD tracks show a 4db difference in overall volume to their DTS
counterparts, a lot of people might perceive the higher volume as
better sounding in an A/B test. If i would work for Dolby that would
itch me. Whats your opinion on Warner choosing to record all their
DD/DTS DVDs with a DN value to make both tracks equal?
[Brent_Butterworth] In terms of sound quality, it doesn't really
matter. What you'll notice, though, is that any disc with a dialnorm
setting of -31 will sound louder than your other DVDs (and DTV
programs, if you have that), and you'll have to turn the sound up.
That's just what dialnorm was supposed to prevent. It's a great
technology, and it's a shame that it wouldn't be used for this
[AdamBarratt] As I understand it, Dolby Digital is a constantly
evolving technology. Could you give us a rough idea of what
generation the system has reached and how often evolutionary
iterations are implemented in the system.
[Brent_Butterworth] Great question! We're working on version 7.0
right now.... ...and that will include a Surround EX flag, and a
flag for material that was produced with HDCD A/D conversion. Since
DD came out in 1993, and we're on version 7.0 (with lots of "point-something"
versions in there), that means we've average a major revision every
year or so.
[NathanPatrick] Returning to an earlier question, I am an electrical
engineering student and am interested in a career in audio/video
design....how do I get my foot in the door? I have the option of
coop and was wondering if you knew any companies that hire coops.
[Brent_Butterworth] Coop? Is that like an internship? And where do
[NathanPatrick] sort of, Cincinnati....Go to the University of
Cincinnati. We alternate work/study quarters.
[Brent_Butterworth] Not much around there for CE. I don't know about
coops, but one thing you might want to consider if you want to work
in CE engineering is that much of that takes place on the West
Coast. I don't know about other companies, but Dolby is always
looking -- we always seem to have vacancies to fill. If you want,
send me a resume or something and I'll get it to the right person.
[Steve_Simon] With PLII only being in Super Expensive Gear (Tag M.
ECT...) right now, how long will we have to wait until it's a
mainstream format, and affordable?? Killer with Chow Yun Fat would
scream for PLII Processing!!!
[Brent_Butterworth] You only have to wait until April, for Kenwood's
$300 PLII receiver. I think Onkyo will come in at $300, too.
[Dan_B] Dolby has been involved recently in the licensing and
marketing of their technologies in videogames. Being a gamer in
addition to a home theater enthusiast, I was wondering if you had
any comments or insight about Dolby's technology being used in
gaming or applications other than movies. Thanks for attending this
[Brent_Butterworth] Yeah, I think it adds a lot to games, as you can
imagine! We will be coming out with new technology very soon that
will make Dolby Digital much easier to incorporate into gaming
platforms, and we're also involved in all of the latest (and
upcoming) game platforms. But I'm not the expert on that....
[AdamBarratt] Could you provide a little detail about Dolby Labs'
role in the ongoing development of Digital Cinema?
[Brent_Butterworth] Sorry, that's somebody else's bag! We have about
550 people working at Dolby, so there's always a lot going on I
don't know about. But I'll study up so I'm ready for that question
[NedVogler] First of all Brent, thanks for coming! In regards to DPL
II, do you know of any manufacturers that will be offering add-on
decoders for DPL II which will integrate with current amps. and
receivers with 5.1 inputs?
[Brent_Butterworth] There's a question I haven't heard! I don't know
of any manufacturer planning that, although they could do it pretty
easily. I think with Kenwood and others coming out so aggressively
with affordable PLII product, few manufacturers will want to make an
[Vince_Maskeeper] Wondering about any possible test discs for home
theater from dolby in the future. I know you touched on a DVD-A
calibration disc. I owned the "Dolby Test and Demo disc Volume
1" and have found it to be an INCREDIBLE source of calibration
tones. Just wondering why dolby is not interested in coming out with
an official disc along the lines of Video Essentials for proper
audio calibration? Seems like a natural product to come direct from
Dolby, and there certain is a market (as VE and Avia sales have
[Brent_Butterworth] Vince, I can't really answer that question. I
just don't know. Guess I should ask!
[Vince_Maskeeper] Well maybe something to suggest!
[Chris_Chiarella] Hey, Brent! Sorry I missed the forum that you,
Dave DelGrosso of DTS and Maureen Jenson of HOME THEATER Magazine
did at CES last month. Two questions: What was said and was it
[Brent_Butterworth] Oh, gosh, I can barely remember! The comment
that stuck most with me was John Dahl's of THX -- he acknowledged
that dipoles aren't appropriate for monitoring material (i.e., 5.1
music) that's recorded with 5 identical monitors equidistant from
the listener. And he said THX is investigating solutions to that
problem -- maybe some kind of automatic switching! Sounds very cool
to me. No, it wasn't bloody, although I did spill my water glass.
Say hi to the gang at HT/HTI for me, Chris!
[AaronMK] I am a college (UVA 1st year Engineering). To follow up on
a previous question. What would be a good minor if I wish to become
involed in the creation and mixing of movie soundtracks? I Realize
it is probably a tight field so I would not make it a major :)
[Brent_Butterworth] I don't know 'cause I'm not involved with that
end of the business. But I could ask one of the guys who is.
[Chris_Maynard] is there any value added (sound quality) to going
above the 448kbps mark with the DD codec?
[Brent_Butterworth] I haven't heard it, but I'm hoping to experiment
with that on my home recording rig. I expect there would be a
difference, since I think the difference between 384 and 448 is
audible through a good system.
[Tommy_R] Hi Brent, if you don't mind me asking, I and I'm sure
others would like to know what current components make up your "personal
system"? What does a man behind Dolby Labs prefer to use in the
comfort of his own home?
[Brent_Butterworth] I just moved, and every time I move, I change
out my system. I move, on the average, almost every year! Right now,
I have an Outlaw receiver and one of the Definitive sub/sat systems
(can't remember which one), although I am getting some of the little
Genelecs, plus a sub TBD. My video rig is a Zenith Pro900 projector,
an RCA DTC100, and a JVC DVD-A player. Plus lots of other stuff!
[RonEastman] This kind of relates to Chris's question. Has there
been any thought of developing a "Super Dolby Digital"
with a higher bit rate to compete with the niche that DTS is
[Brent_Butterworth] No, we don't think it's necessary. Once you get
rid of all the variables and compare DD at 448 kbps to DTS at 1509
kbps, you hear that the differences are almost nothing. (Actually,
some people think DD sounds better, and I think it definitely sounds
better at 448 than DTS does at 754 kbps.) Our attitude is, you don't
NEED to do that. When you hear an A/B comparison with the original
master, Dolby Digital is almost transparent at 448 (no codec).
[BarryLieberman] This tangentially relates to an earlier inquiry;
I've read many different interpretations of ideal surround,
everything from Brian Eno's early 2 fronts and one rear to
Ambisonics, to the more modern incarnartions. Do you believe there
to be a 'golden' format that is commensurate with human hearing
properties? 5.1, 6.1, 10.1...?
[Brent_Butterworth] It'd be hard to exhaust the human ear's ability
to locate sound.
[BarryLieberman] Indeed, but where does diminishing returns come in
[Brent_Butterworth] I think 5.1 will be the standard for surround
sound for a long time to come -- maybe forever, at least in the
home. Where the returns diminish is a matter of opinion. I'd say
[Bjoern_Roy] Final question: Do you have a bad conscience if you
ever listen to a DVD in DTS?
[Brent_Butterworth] No. DTS sounds good. All these codecs basically
do -- DD, DTS, etc. Wait till you hear AAC! Luckily enough, we
license that one, too. d
[RonEpstein] I want to take this opportunity to thank our guest,
Brent Butterworth. It has been an absolute pleasure to have you here
tonight. I also want to thank Ned Vogler for a great job Moderating
[Brent_Butterworth] Hey, thank YOU! It has been a lot of fun.Great
job, guys! Let's do it again sometime!
[RonEpstein] You are ALWAYS welcome back for a chat
[ParkerClack] Brent. How do you like the Outlaw and I would like to
suggest that you check out an SV Subwoofer that you can get to
through our forum since you are still deciding on one.
[Brent_Butterworth] I love the Outlaw and would like to hear an SVS!
[RonEpstein] I'll open the floodgates so people can tahnk you
[Brent_Butterworth] Thanks, guys! It's been fun!
Session Close: Tue Feb 06 23:06:18 2001
Copyright 2001 Home Theater Forum. Reader may not modify, publish,
transmit, participate in the transfer or sale or in any way exploit
any of the content of transcript, in whole or in part, without the
express prior written permission of the copyright holder.