Transcript
PSW Live Chat With Peavey’s Charlie Hughes
April 2, 2001

(Moderated by Dave Dermont)

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?

Charlie Hughes: 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 stuff.

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 install-type stuff.

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 & MediaMatrix.
I also have a small, part-time audio company.

JoshM: Could you please enlighten us as to this "Quadratic Throat" technology you published?

Charlie: The 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 spherical.

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 designs.

Moderator: Charlie, I'd like to ask something a lot of the audience is thinking, but too polite to ask.

Charlie: OK.

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 them.
TRIP!: Is it the way “pro's” perceive Peavey as a MI company?

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 gear.
We are not the same company we were 10, or even 5, years ago.

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 job?
B) Was the product used ever intended to function as it was being used?
C) You heard from someone that Peavey sucks?

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 loudspeakers.

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 deletion?

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 Georgia Tech?

Charlie: Yes. I graduated from Tech with a physics degree. I studied there under Dr. Patronis.

JoshM: What is going to become of the Q-Factor line? What is there looks pretty cool. Is there going to be more models?

Charlie: 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.

TRIP!: Do you think that may be a problem with Peavey in that everyone expects a cheap piece of gear, monetary or otherwise?

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 Q-Factor?

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 product.

ron b: Does Peavey manufacture products under other labels than "Peavey"?

Charlie: No. Peavey does not OEM for anyone.

EM7: When does the powered speaker line come out? Will they be concert powered speakers as well as “on a stick” variety?

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.
We have an entirely different engineering department for that area.

TRIP!: And what products do you have that a Showco or an Electro-Tech might say “Man, we gotta get some of those!” (Other than MediaMatrix.)

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 nice unit.

TRIP!: It's been said that your R&D department rocks! What advantages has Crest been blessed with by this?

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?


Charlie: Crest 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 the bandwagon.

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 application though.
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.

MarkA: Anything 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 systems.

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.

Charlie (continued): Used properly though, line arrays can still be very useful.
I don't know how much had to be done to get around the Heil (V-Dosc) patent.

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 possible?

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 frequencies.
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 thing.

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 entire plane.

Charlie (continued): There is some graphs of some simulations I have done posted on my web site. The URL is <a href="http://www.mississippi.net/~charlie" target="_top">http://www.mississippi.net/~charlie</a>, click “Articles”. There’s a bunch of stuff there.

MarkA: 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.

JoshM: 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.

Charlie: Good 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 there.

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.

TRIP!: Isn't this where delay hangs would come into play?

[03/Apr/2001:03:11:33] <Charlie Hughes> Not really
[03/Apr/2001:03:12:10] <Charlie Hughes> Well, I'm not sure what you mean
[03/Apr/2001:03:12:15] <Charlie Hughes> Please clarify.
[03/Apr/2001:03:13:02] <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 little pieces.

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, etc...

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 well

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 weight.

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 boxes?

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 feel.

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 design needs?

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.

Charlie (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 website?

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.
Crest will 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 there.
If you are interested in the AES paper I presented, it is available on my web site, at the URL supplied earlier in this chat.

Tom Young: How much involvement have you or anyone from Meridian had in the design of Crest's loudspeaker line?

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 consoles.

gus: Will the Q-Factor line be resurrected?

Charlie: I doubt it. At least not in it’s previous form.

Moderator: This will be our last question for the evening.

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”.

Charlie: Thanks to Dave for his wonderful job of moderating.

chat.boy> Join us in the PSW Live Sound Chat room to continue the discussion.
Good Night!