Here's a little bit of what I do. - Woodworking Talk

HexiBase · 09-08-2008, 07:10 PM

Well, right up front, I should mention that I do acoustic engineering as a way to make ends meet. Aside from the science of sound, I also like to get my hands dusty, building full range and subwoofer enclosures for my clients. It's nothing too overly elaborate, especially in comparison to some of the fine work that I've seen you guys post up but here are some pictures from my WorkBlog:

And there's a bunch more in my WorkBlog at pwkdesigns.com

Handyman · 09-08-2008, 07:21 PM

HexiBase

HexiBase What do you make the boxes out of? It looks like MDF. I built my sound system a few years back for my house. All big boxes with big speakers. But my boxes arent nearly as nise as yours.

HexiBase · 09-08-2008, 07:44 PM

MDF indeed, Handyman. Even when the enclosure budget is not a factor, I still prefer MDF over hardwoods mainly because of the damping-to-rigidity ratio. With MDF enclosures, even without inner-chamber damper / diffuser panels, the typically jagged spikes in the response that are indicative of half-cycle standing wave multipliers between two parallel walls inside of an enclosure are much more tame, imposing a lot less "coloration" to the sound, especially along the lower vocal octave. Surprisingly many ultra high end speaker manufacturers use MDF if their cabinets. Bose, on the other hand, has been known to use particle board

Terry Beeson · 09-08-2008, 10:48 PM

Yep... what he said...

I think Bose uses some particle board because they think the rest of the engineering will overcome it. Most of the speakers I've dealt with over the years that were of any value were MDF based - Including guitar amps.

What kind of work do you do, Hex? Sound systems for auditoriums/churches/etc? Auto? I like that second pic... where would the highs come out, though?

TheRecklessOne · 09-08-2008, 11:01 PM

Very cool...I don't know about all the technical mumbo jumbo...too smart for me. I've always wanted to build some large speaker boxes for my wifes car.

HexiBase · 09-09-2008, 02:09 AM

Thank you all for your positive comments. Terry, I engineer (and, as you can see, sometimes even assemble) for a very wide variety of clients and listening environments. From dedicated listening rooms, to home theaters, to car audio subwoofers, to PA systems. That second pic, that is a subsonic horn (essentially a sub-subwoofer) for a client who wanted to experience infrasonics in his vehicle. The highs are taken care of by his front stage.

Terry Beeson · 09-09-2008, 09:33 AM

Hex... Nice business. I ran sound for several years and then was the head sound guy at my church before moving a couple of years ago. I guess I should have put a laughing smilie behind that part about the highs, 'cuz I could tell that was a sub... The church I ran sound for had similar sub-subs mounted under the stage. We did a "thunder" scene in a play once and ran it up to something like 120(?) Db during a sound rehersal. They could actually feel the parking lot vibrate... Needless to say, we toned it down quite a bit for the real thing.

I could have used your talents there, though. The system was a high budget one, but not designed very well for the venue. We made changes that helped a lot, but I was never really satisfied...

themechanic007 · 09-09-2008, 12:26 PM

Love the speaker boxes-
I need to build a couple for my gazebo-lol, I got old and took all my sound equipment outa my car and put it in my gazebo by my hot tub...im running 2- 6X9s full range 2-4" getting only highs and 2 old 10" realistic full range speakers that im using as subs underneath the hot tub- powerd by a 1000K watt rockford amp and a 250W pioneer amp all run off a pioneer head unit, im using a 12v deep cycle battery and a charger to power it all...it sounds ok-but could be better! I tell people im gonna start a TV show called "PIMP MY GAZEBO"... ;D

Any good links for building boxes on our own?

**TexasTimbers** · 09-10-2008, 08:33 AM

Hexi, Way cool business. I too am a longtime supporter of taming the typically jagged spikes in the response that are indicative of half-cycle standing wave multipliers between two parallel walls inside of an enclosure, so as to impose a lot less "coloration" to the sound, especially along the lower vocal octave. Yessiree. One day maybe you will have time to explain to me what the heck I just said.

Anyhow welcome to the family.

Handyman · 09-10-2008, 11:11 AM

Hexibase what type of glue are you using?

HexiBase · 09-11-2008, 03:48 AM

themechanic007, there's really no one correct way to build a speaker box just like there's no one correct way to build a table or a dresser. As long as the enclosure is air-tight and properly braced, there's no limit to the assembly techniques. You could even join the panels with dovetails if you felt so inclined; a lot of it comes down to aesthetics. The design, on the other hand--that's a whole another story. There's quite a number of speaker D.I.Y. web sites out there but most of what they offer is theory with a cookie cutter approach, not necessarily specific to your particular listening scenario.

TexasTimbers, thanks for the welcome; glad to be here. By what you've quoted me say, I simply meant to describe the adverse effects of waves bouncing around inside of an enclosure

Handyman, I typically use TiteBond III.

Woodchuck1957 · 09-30-2008, 10:40 AM

Inside the sub is a bent piece of wood, is it MDF ? and how do you bend it ? Or is it a laminated bend ? Great looking boxes.

J.Tizzle · 10-06-2008, 03:42 PM

Hexi, those are flippin' sweet! They look like some molded plastic foam thing. Very nice.

HexiBase · 10-07-2008, 04:43 PM

Thanks guys. In order to bend MDF, I cut notches into it at a specific depth and distance from one another; it just depends on the radius that I'm going for. I fill the notches with "putty" that I make by mixing fine MDF saw dust into a cup of wood glue, then I use a couple of ratchet bars to achieve the proper bend, finally I let the putty set. The end product is a bent MDF panel that's as strong as a flat sheet. If done right, I can actually lay the bent panel on the ground, place my feet on either end, and use it as a rocking chair of sorts (mind you, I'm a big boy; 300+ lbs)