Need ideas for Christmas present

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So I have 12 of these B3S' from Hi-Vi sitting here. I was thinking about making a surround sound set for my father in law using the filter networks from www.zaphaudio.com . Now should I build cubes for these things, or throw them in some PVC and make some keyhole notches on the end cap?

I'm open to any and all ideas on how to use them in a build.

[morbo]

well, if you intend to build Zaph's design, you will need to maintain the exact baffle dimensions and placement he used. If you want to design your own filter, you can get creative with the shape/size.

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I should've been more clear. I intend to use the notch filter for the cone breakup, and probably a single order 100Hz high pass due to the severe distortion he mentions.

[morbo]

I think you will probably want some sort of baffle step compensation. Try downloading The Edge or BDS:

http://www.tolvan.com/edge/help.htm
http://www.pvconsultants.com/audio/d...ownloadbds.htm

It will allow you to get an idea of how your driver will behave in various shaped/sized baffles. Then if you do decide to do a BSC circuit, it will also generate a starting point circuit based on the baffle you choose.

Since you have so many of the drivers, you could also try a 1.5 way design, putting a first order lowpass on the .5 driver around the baffle step frequency to compensate for baffle step. This would also give you more clean output. CSS used to have a kit like this with the TB871, I think it was called the ELF 1.5. which got high praise.

A 100hz 1st order highpass is going to do very little to tame excursion. You would be much better off using the receiver's bass management to apply a 150hz or so highpass. The 100hz 1st order lowpass will have the same problems as using a plate amp's speaker level crossover, which Zaph explains on his site as well.

Personally, if I didn't have measurement/modelling capability, I would probably just build the design exactly as Zaph specifies. Just my $.02.

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Thanks, will do. Good point on the low pass. Yeah, I suppose I should follow the Zaph blueprint. These B3Ss test just as Hi-Vi states with the woofer tester.

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I'd like to hear thoughts on this cube design.

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Okay, giving my father-in-law my two-way bookshelves that served as my center channel.

So, now I have 12 Hi-Vi B3S's to play with to replace my center channel. In drawing up plans for their use, I'm considering doing a 2.5-way using a cabinet that will fit perfectly on top of my Mitsu Projection Screen. The dimensions are 50.5" wide, 12.75" deep, and I'll probably make the enclosure 5.5" tall to accomodate a BG Neo 3 PDR with faceplate. That should give me an internal volume ~ 1.3 cubic feet using 5/8" MDF for everything except the 3/4" baffle. The predicted F3 would be ~ 67Hz when using two 3" diameter ports that are 4" long. Among my worries early on, is the Xmax at which the distortion occurs mentioned at www.zaphaudio.com, or if it is just inherent in the design of the driver.

I will have to come up with a wiring scheme to keep all 12 at a benign impedance for my Yamaha HTR-5860. I can come out with a final impedance of 6 ohms in a series-parallel wiring scheme, but I have no idea of what the SPL might be @2.83 volts. Will post more as the project moves along.

If this sounds like a waste of time, speak up and slap me around.