Parts Express Low cost DIY Home Theater Project

[figure8]

Re: Parts Express Low cost DIY Home Theater Project

Finally finished, or at least as finished as I'm going to go with this speaker. I learned a lot with this project but I wouldn't do it again knowing what I know now. I'd have chosen a different woofer for sure, and probably a different tweeter too. But in the end it was an excellent learning experience. The final speaker is a bit ugly to look at but nothing paint can't fix and it sound good. The Vifa tweeter does not cross low despite it's relatively low fs. It would not cross below 3K without sounding like a blender crushing ice even LR4. With a steeper slope you might get it to cross at 2.7K or so where I had it yesterday. It sounds "acceptable" if you don't have a sensitive ear, otherwise it sounds harsh so I moved the XOP up to 3K and it sounds much better. Still a hint of sibilance but I think it's in the source as it varies with recording. I also don't know how neutral this amp is. It's a THX amp so it might have the crisper top end typical of HT gear.

Horizontal polar plots look excellent. No dips or peaks to well beyond 30 deg, despite the offset tweeter. I can, however, measure the diffraction effects on the tweeter but they disappear at 1/3 octave. I'll take another round of measurements and update this post later today. I change the crossover a little this morning so yesterdays plots are a little outdated. Since this is a "stereo" pair of speaker and I haven't learned the lingo yet, here are my first round of polar plots. I guessed at the angle between 0 and 45 and between 45 and 90. Even an inexperienced person can tell this looks good if you want wide dispersion.
[ATTACH=CONFIG]33559[/ATTACH]

Frequency Response on axis. Not really the smoothest thing but it sounds OK and it's my first finished design. That peak between 1 and 2 k is not really prevalent when listening. The 200Hz peak I can't explain at all. It's not there in nearfield measurements so it has to be the enclosure somewhere. I'll double check for leaks. It might be the rear of the baffle not chamfered enough. It also doesn't measure the same on the other enclosure so it's got to be something in the enclosure. When I get ready to paint it I'll see if I can track it down. I'm pretty sure I chamfered both baffles...
[ATTACH=CONFIG]33560[/ATTACH]

Thanks for all the help building this thing. I didn't even know phase was part of the crossover until earlier in this thread and I've learned about asymmetric crossovers with this speaker. A technique I'm sure I'll put to good use in the future.

Do you have a schematic for the crossover you finally ended up with? Thank you; Phil

[siggma]

Re: Parts Express Low cost DIY Home Theater Project

Yea, somewhere. I gave them to my son. He uses them for his big screen TV in his basement. Drives them with a 200W digital amp he bought on the internet.
Pretty sure this is it. I ended up using a pseudo notch filter for the Visaton based on an XO published on their site for this woofer. It sounds good but sensitivity it a bit low. 84DB if I recall. Good horizontal dispersion, reasonable bottom end for a 5", decent detail and excellent stereo imaging. Very nice stereo image. For a HT I'd just build another one of these for the center.

Unfinished verson here. I later added a small riser to the bottom to house the XO but it's not really necessary. Don't expect tons of bass from these things, they are designed to be augmented by a sub below 80Hz~100Hz. The other pics are the Paduk baffle speakers I built for my HT. I built 5 satellites. They sound very nice.

Tom