PSW Live Chat With Peavey’s
April 2, 2001
Moderator: Welcome to our chat with Charlie
Hughes. First, Charlie, could you give us some background on who you
are, what you do, and how you got there?
Sure. I started out working with a lot of different local bands when
I was in high school. In the mid ‘80s I studied physics at Georgia
Tech. After I graduated I went to work for Peavey as a loudspeaker
design engineer. Been here ever since.
Charlie (continued): I
have worked on a lot of different types of projects in the last 13
years, everything from entry level PA to the Peavey SP line, the DTH
and the Q-Factor stuff. I have also worked on guitar and bass guitar
cabinets, and played a small part in the early 5150
Charlie (continued): Most of the recent bass guitar
stuff is mine (TX, TXF & TVX lines). I’m also heavily involved
in the QC (quality control) of our final assembly loudspeaker lines.
I pretty much designed the setup and procedures we’ve been using for
some time now. Over the past several years I have been mostly
involved in our Architectural Acoustics division. Permanent
Charlie (continued): In conjunction with
this, and the upper-end MI systems, I’m also responsible for EASE
data entry and processor presets, CEX 5, X Frame &
I also have a small, part-time audio
JoshM: Could you please enlighten us as to this
"Quadratic Throat" technology you published?
Quadratic Throat Waveguide is a horn design I came up with a couple
of years ago. It’s based on the geometry of the throat and how this
blends into the body of the horn. The nice thing about it is that
the apparent apex for the horizontal & vertical planes in the
same point in space. No astigmatism of the wavefront - it is truly
Charlie (continued): The other thing I discovered
- only after building prototypes - is that the odd order harmonic
distortion is dramatically decreased. Third-order distortion is
about –9 dB relative to conventional constant directivity
Moderator: Charlie, I'd like to ask something a lot
of the audience is thinking, but too polite to ask.
Moderator: Peavey is well respected in the MI and install
biz, but in the "PRO" world, we see lots of "No Peavey" on tech
riders. You are not a marketing guy, but can you address this issue
the best you can?
Charlie: Well I really can't say why folks
out there have “No Peavey” riders. You would really have to ask
TRIP!: Is it the way “pro's” perceive Peavey as a MI
Charlie: It may have to do with our supplying to a
wide variety of price points and performance levels. I really liked
a recent thread on the LAB about this issue. Jim Gould pretty much
summed it up. It has more to do with "pilot error" than sub-standard
We are not the same company we were 10, or even 5, years
Charlie (continued): A lot of things have changed around
here. For the better, in my opinion. For those folks out there who
have “No Peavey” riders, I would ask:
A) Have you personally had
a bad experience using properly selected Peavey gear to perform a
B) Was the product used ever intended to function as it was
C) You heard from someone that Peavey
Charlie (continued): If the answer is “A”, I welcome
any and all comments, suggestions and criticisms. I can’t improve it
if I don't know what's not right. If it's “B” or “C”, I would
respectfully ask that you give Peavey a serious, unbiased chance.
Just give it a listen. You might be surprised. If you haven't heard
our loudspeakers in the last 3 to 5 years, you haven't heard our
ron b: What is the strategic direction of the
company? What can we expect over the next couple of years? Any
Peavey product lines slated for expansion or
Charlie: Well. I'm not exactly at the corporate
level that sets this, but... You can expect a quality product at a
fair price. We try to revamp a product line every so often. If a
line has been out there for a while without changes, expect it to
get some in the near future.
EM7: Did you get a degree a
Charlie: Yes. I graduated from Tech with a
physics degree. I studied there under Dr. Patronis.
What is going to become of the Q-Factor line? What is there looks
pretty cool. Is there going to be more models?
Unfortunately the Q-Factors were not received well. We had some
problems introducing them to the market. Folks didn't expect to see
a Peavey product with the price tag that these carried. I believe
that they have been shelved, but I’m hopeful that we will be able to
do something similar, but better, and less expensive.
Do you think that may be a problem with Peavey in that everyone
expects a cheap piece of gear, monetary or
Charlie: I think this may be a general perception.
Historically, Peavey has been the low- price product out there.
Because of this folks may not be willing to give it shot. Or, when
we come out with something that is around the same price as some of
our competitors, they (the market) balk at it. This is something
that is a continual frustration. The only way to change this is to
keep putting good product out there. Slowly, folks will see that
what we do is not all-cheap, entry-level stuff.
JoshM: Do you
think high price, or the fact that it remained on the infamous list
of "Vapor Ware" so long, was the undoing of
Charlie: Probably a bit of both. I think it was
more of the price thing though. We examined stripping the flying
hardware out of it to reduce the cost. There was some interest in
this, but not enough to justify it and reintroduce the
ron b: Does Peavey manufacture products under other
labels than "Peavey"?
Charlie: No. Peavey does not OEM for
EM7: When does the powered speaker line come out?
Will they be concert powered speakers as well as “on a stick”
Charlie: We have some powered loudspeakers available
now, the Impulse Series. We have looked at larger scale powered
speakers a bit, but I can't say if something like this will come to
the market or not.
TRIP!: The MM (MediaMatrix) Line4 and MM
Mic4 are interesting. What are the possibilities of using MM for
multiple IEM (in-ear monitoring) mixes and the compatibility to
something like the Shure P4800? Or, used in conjunction with
something like a Gamble DCX?
Charlie: You're in an area in
which I'm not well versed. I'm mainly loudspeaker design.
an entirely different engineering department for that
TRIP!: And what products do you have that a Showco or
an Electro-Tech might say “Man, we gotta get some of those!” (Other
Charlie: We were hopeful that the Q Factor
line would fall into this category but it's history now. The X-Frame
is a drive unit processor that they might find useful. It is like
MediaMatrix on a smaller scale. It is fully programmable; a very
TRIP!: It's been said that your R&D department
rocks! What advantages has Crest been blessed with by
Charlie: Thank you. I hadn't heard that, so it's nice
to hear. Crest engineering is still a separate and distinct entity
from Peavey engineering. The Crest folks are up in New Jersey and
we’re down here in Mississippi.
Moderator: So Peavey has
nothing to do with the Crest loudspeakers?
didn't formerly have loudspeaker R&D. There are a couple of
folks here in Mississippi dedicated to Crest loudspeakers. They keep
in close contact with the folks in New Jersey. We all help each
other out to a certain extent.
Trooper Hales: Any line array
stuff in the works from Peavey? Everyone else seems to be jumpin’ on
Charlie: Hi Troop. No line array here - that
market seems pretty well saturated right now.
ron b: Any
R&D breakthroughs coming in speaker design, or does this
essentially stay the same?
Charlie: As far as the raw drivers
are concerned, everything has been pretty much the same for the past
50-plus years. Adhesives and material are more fully developed, but
the main underlying principles are the same as they were in the
early part of the 20th century.
Charlie (continued): The only
really new thing is the distributed mode loudspeaker that NXT in
Great Britain has come up with. These are fairly limited in
Cooling of the loudspeaker voice coil has
come a long way in the past several years.
Vented gap cooling,
Air Force and others. We introduced some vent technology for the
loudspeaker enclosure a while back that helps a bit with this. Look
for more of this type of stuff in the future.
in the world of new passive crossover technology happening for
Peavey? And/or in the Industry?
Charlie: Good question. A lot
can be done with a good passive crossover. The higher the quality of
components used, the more you can get out if it. Several years ago
we did some in-house testing with polypropylene caps versus other
types. The sonic differences were amazing. Since then, all of our
mid- and upper-level systems have been designed with polypro caps in
the signal path.
Charlie (continued): Good quality caps and
good design also enable higher power handling systems. We check the
voltage and current limits of all of our passive crossover designs
to make sure they can withstand full rated power and then some.
Impedance compensation of the load that the drivers present to the
crossover is something we have been doing more of on our higher end
Charlie (continued): This allows the crossover to do
its job more effectively, and it also helps to present a more benign
load to the amplifier. Some amps have a very hard time driving a
load that is highly reactive. That is to say, more capacitive or
inductive than it is resistive.
Charlie (continued): You have
to look at the phase angle of the impedance that the crossover is
presenting to the amp. We make sure this is kept under 45 degrees;
every once in a while it may creep slightly above that, but not by
much. If the amp doesn’t like the load, it can have a lot to do with
the sound quality.
TRIP!: What do you think about the whole
line array explosion? Are people just trying to get around the
V-Dosc waveguide patent?
Charlie: I think line arrays can be
very effective in the right application. You must remember that to
get the -3 dB / doubling of distance you must remain in the near
field of the line. Once you are in the far field, the level falls
off at -6 dB as the inverse square law dictates. This means that for
some of the large venues, the line array reverts to a point source
when you’re sufficiently far from it.
Used properly though, line arrays can still be very useful.
don't know how much had to be done to get around the Heil (V-Dosc)
Trooper Hales: So what about pattern control down to
around 300Hz in a box that’s not as big as a VW? Will it ever be
Charlie: Sure. Just don't use a horn to do it. The
spacing of direct radiators and the appropriate filtering can be
used to get reasonable pattern control to very low
Craig Janssen was issued a patent several years ago
on this concept. EAW employs this in the TDA Series. We can't sell a
box that does it exactly like they do, but that doesn't prevent the
taking of individual boxes and putting them in the right places with
the right filters driving them to do exactly the same
Charlie (continued): I written some software for
MATLAB that helps to do a lot of this.
MATLAB is a program that
does some serious number crunching. It also has great data
visualization. It allows me to look at directivity data in a very
different way. Instead of looking at polars at different
frequencies, I can view the frequency response of a system in an
Charlie (continued): There is some graphs of
some simulations I have done posted on my web site. The URL is <a
click “Articles”. There’s a bunch of stuff there.
Rumor has it that there are new Black Widows and 22 HF drivers on
the way. Any beans you can spill now?
Charlie: I'll spill it
all!!! New higher power-handling Black Widows, called BWX, will be
available very shortly. Some may already be shipping. The new Rx22
is a complete redesign of the 22xt. These have been shipping for a
while. Our new systems will be using these components. The Rx22 is a
much smoother sounding driver.
Moderator: The following
question goes back to the line array issue, I believe.
Could you please note the difference between "near field" and "far
field"? As in, where does one draw the line and say THAT is the
"near field" and THAT is the "far field"? I guess I'm looking for
exactly WHERE the line is between them.
question. The far field is determined by the size of the device and
the wavelength being radiated. As such, the far field is frequency
dependant. Some guidelines: far field is at least 10 times the
wavelength of interest; also, this distance should be greater than
10 times the radiating area, divided by the highest frequency of
interest. This second case can place the far field WAY out
Charlie (continued): For a 12-inch driver emitting 1
kHz, the far field would be approximately 7 feet. For the same
driver emitting 4 kHz, the far field would be 28 feet.
Isn't this where delay hangs would come into
[03/Apr/2001:03:11:33] <Charlie Hughes> Not
[03/Apr/2001:03:12:10] <Charlie Hughes> Well, I'm
not sure what you mean
Hughes> Please clarify.
<Moderator> you out there, Trip?
Tom Young: This
question came up several days ago on live-audio board: why are
aluminum cones not used in sound reinforcement? They clearly had
some success in bass guitar systems.
Charlie: I'm not much of
a driver designer but I'll try to tackle this. From what I have
heard the aluminum cones are VERY fragile once they are driven
beyond their capabilities. Kind of like digital clipping versus tube
clipping. Paper cones can be made to break up slowly and somewhat
gracefully. When the aluminum cones go, they go, and into a bunch of
Charlie (continued): Since they are aluminum,
they do have good self-damping properties. The cone's resonances can
be pushed up above the range of typical use, or tailored for a bit
of extended HF response.
gus: What about the use of other
composites in driver design? Kevlar, carbon fiber,
Charlie: We have used Kevlar for quite some time in
our woofers. I think we were one of the first in the industry to do
so. It can add a lot to the damping of the cone and helps to greatly
minimize "cone cry". I haven't had a chance to play with a lot of
carbon fiber drivers. I'm sure they can do a good job as
Charlie (continued): However, I would think that the
cones would be very expensive. I would also be concerned about the
weight. Carbon fiber can do wonders in an air frame when it is
replacing steel or aluminum, but when you are replacing paper,
chances are that you are greatly increasing the
Charlie (continued): For LF systems, when cones are
subjected to very high pressures (like a band pass enclosure) carbon
fiber may work well. For smaller types of diaphragms, they may also
work well. I think Bruce Howze at Community uses carbon fiber for
some of his HF diaphragms.
Weogo Reed: What about carbon
fiber boxes? Do you see this feasible when making lots of
Charlie: VERY expensive - I think a properly designed
wooden box that is well braced can perform on a par with a carbon
fiber enclosure. Of course, the wood box will probably weigh more.
If rigging limits are a concern, then carbon fiber may be the way to
go. On sheer economy of scale, I think wood over carbon fiber, but
I've never really looked at it hard. This is just my gut
Harry: If you don't design the drivers, then are you
kind of stuck, making the best of what you have? Are you given the
opportunity to specify what you want from a driver to meet your
Charlie: I personally don't design the drivers.
We have a couple of very good driver engineers here. If we need to
make modifications to an existing driver, I can go to them and say,
for example, that I need a lower Qts or a higher Fs or what ever.
They can then execute what I need and provide it.
(continued): This worked very well in a recent product in which I
needed a lower Qts for tighter LF response. They were able to take
the existing driver and replace the aluminum voice coil with a
copper one. It worked great.
Tom Young: Does the new
loudspeaker line from Peavey employ vertical astigmatism-correcting
horns, as described in the white paper on Peavey's
Charlie: The Quadratic Throat waveguide is employed
in the ILS line of loudspeakers, available through our AA division.
They are also available in the Quadra line from AA.
have these in the LQ Series.
Charlie (continued): The white
paper that John Murray wrote was a pretty good distillation of my
AES paper, with the addition of the different types of horns out
If you are interested in the AES paper I presented, it is
available on my web site, at the URL supplied earlier in this
Tom Young: How much involvement have you or anyone from
Meridian had in the design of Crest's loudspeaker
Charlie: Until Peavey acquired Crest, there was no
Crest loudspeaker engineering. Now there are folks dedicated to
Crest loudspeaker development, just as they are for amps and
gus: Will the Q-Factor line be
Charlie: I doubt it. At least not in it’s
Moderator: This will be our last question for
TRIP!: Sausage/red beans and rice or seafood
gumbo? Your choice.
Charlie: Well, I love good gumbo made
with a dark roux, but red beans and rice are good as well. If I have
to choose... GUMBO.
chat.boy: On behalf of the ProSoundWeb
team, I'd like to thank Charlie for sharing his time and knowledge.
This concludes our chat with Charlie Hughes. The chat was moderated
and organized by Dave Dermont, "Another Dave”.
Thanks to Dave for his wonderful job of
chat.boy> Join us in the PSW Live Sound Chat
room to continue the discussion.