DIY Open Baffle Full Range Speakers from Wal-Mart . . .

[loudandclear]

Have to share a photo of my very first DIY Speaker Project.

Visaton B200's arrived today (Thank you Solen!).

I just could not wait until the weekend to buy a sheet of plywood & get to someone's shop (we live in an apartment) to build some nice baffles.

So this evening I ran down to Wal-Mart, searching all over the store for anything that might work, at least temporarily anyway. Lo and behold, I ended up bring home a pair of 22x34 cork bulletin boards with some nice oak trim (I know, not the best for diffraction) for all of $13 each!

I did some "Golden Mean" calculations for speaker hole placement. Whipped out the jigsaw and cut out the holes in the kitchen - No problem!. The holes for the bolts were a little more tricky as the drill bit would break off some cork as it exitted the backside. No worrys. The speakers bolted in fine.

Hooked them up and WOW! Open Baffle sure is what everyone says it is! Very open, clean & natural. Sure notice the lack of that "Box Sound"

The B200's are very quick and smooth - and they have some breaking in to do yet. Bass is a bit shy of course, but still is more than I expected. Treble extends nicely. This is going to be a late one!

Thanks everyone here for the inspiration & motivation and also for letting me live vicariously (up until now anyway) through your experiences.

Don't worry, I'll get those B200's in a nice set of baffles soon enough, probably with a sub of some type in the bottom of each.

I'm calling these the "Corky's". Incredible sound for less than $350!

Now I'm thinking about a decent SET amplifier. And maybe the Fertin voice coils one day as well.

Fun stuff.

PS: Yep, that's a towel over the TV (to avoid the camera flash issue)

[Ropie]

Plus you can keep your diy thoughts/sketches pinned conveniently close to hand.

[adason]

hi loudandclear
nice job
i have been big fan of open baffle for a long time, but you can never expect adequate bass from one full range on open baffle
here is the option how to continue the project
http://www.blackdahlia.com/html/tip_45.html
enjoy
ed

[TomekZ]

As is, do you find the bass warm and satisfying...though not too deep?

With my recent mounting of the CSS FR125S on open baffles, I'm convinced, without a doubt that this is the best way to mount a driver. And the Visaton B200, being designed for an open baffle certainly has aroused my curiosity.

[Scottmoose]

For future use, I'd go with two of them, dipolar, mouted either on a flat baffle or an H frame with EQ, preferably active unless you've got 200W available from your amp to pump into them, in which case passive is possible (though not as good). Should give you decent lows, but maintain the dipolar benefits, which are at their most pronounced in my experience in the bass and lower-mid regions (ironic, as this is the most difficult thing to do with dipoles) in preventing or reducing the influence of the room.

I like the idea of the cork boards -novel, and attractive too. Wish I could find somewhere in the UK that makes decent ones for a reasonable price. Looks great to me!

Best

[loudandclear]

Thanks Guys!

@Ropie:
Yep, my partner suggested taking the picture with a bunch of paper & notes pinned to the boards but I thought that would be a bit too "tacky".

@adason:
I have always been intrigued by the Basszilla. I think I may go a little different route though. I'm hoping to have a seperate amp/Eq for the Bass and try to do it with 10" or 12" drivers. I think the B200's go lower than the Lowthers and Fostex do in OB, so hopefully I can get away with a fast sub of sorts (probably in a sealed enclosure) like the Rythmik or maybe using a TCSounds driver. I'd be happy with response down to somewhere around 30hz.

@TomekZ
"Satisfying" is fairly relative. I listened to these guys for a few hours last night no problem. It is warm & natural bass and is not "one-note" resonant which i hear in so many systems. I have to admit though, it could use a boost (for my tastes) in the lower registers. I need to play with some wings and come up with a good plan to integrate a pair of subs.


One other note I'll have to add is that these are my first full-range drivers so I am getting the double benefit of both no-crossover and open-baffle. I think what else has bothered me with a lot of speakers (we listened to 50 or so pairs when buying our last set) is suboptimal driver integration. Having no crossover in the "presence" range is so alluring (preaching to the choir here!).

[loudandclear]

@Scottmoose

I'd love to keep the added bass drivers dipolar!
I come up to two issues. I want to get the baffle width down to 16" so large "pro" drivers are out.

Then, I have been modelling a bunch of drivers (subs and woofers) in Thorsten's xbaffle.xls and have not found anything that is going to give me a significant boost in bass using one driver in an OB. I see why a lot of dipolar bass implementations use multiple woofers. The B200 actually gives better OB bass response than most 10" and 12" drivers I have modelled so your idea of using another one may not be so bad!

H or U baffles are a definite consideration as well. I wonder how a couple of EQed 6.8extremis's in an H baffle on each side would work?

Lot's of planning left to do on this one . . .

PS: the cork boards I used are not actually cork all the way through. There is a thin layer of cork on the surfaces and the middle is some sort of tightly packed fibre. I double stacked a small and large washer on the speaker bolts to make sure I had enough surface area against the baffle, otherwise the smaller washers would sink right into the material.

[Dumbass]

Originally posted by loudandclear
Lo and behold, I ended up bring home a pair of 22x34 cork bulletin boards with some nice oak trim (I know, not the best for diffraction) for all of $13 each!

Edge diffraction shouldn't be a problem because high-freqs already direction with full-range drivers.

[loudandclear]

I did some more experimenting with the Corkys tonight. I flipped the speakers over and changed sides. More weight now and a better balance overall, even with the drivers down that low.

This also gets the drivers away from radiating directly back into the blinds (which are made of metal).

Very educational.

Another idea I had today was that if I were to use cork board again, I would put a block of wood behind them when I was drilling the speaker bolt holes. This would probably prevent the cork layer at the back from breaking off when the drill punched through.

Also, Sixmoons just posted a review of the Omega A8's which use the Visaton B200 where Louis of Omega explained:

"I chose to modify the back wave of the B200. It's basically damping of the cast frame of the driver. I heard a need for this in listening. The damping reduces peakiness in the critical midrange. I try to response-shape by mechanical methods only. I have tried electronic components in the past but they always took the life out of the sound."

Hmmmm, I'm wondering exactly what he did there. Anyone have any ideas?

[Dumbass]

Aha you put the drivers closer to the floor.

If you haven't read JEL's open baffle page, check it out:
http://members.myactv.net/~je2a3/open.htm

There are two basket mods with which I am aware. The first is putting "rope caulk" or similar on frame to damp any vibrations. Popular with stamped frame speakers. The second is wool or felt on inside of basket, to dampen reflections off of the frame.