The PV2.0 Computer Speakers

[mattp]

Hey guys,

Heres a simple, budget friendly small bookshelf design that I came up with that I'm using for some PC speakers here at my desk. It uses the Buyout Peerless 830872 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-240&FTR=299-240) woofer and Vifa NE19VTS-04 (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-1006&FTR=264-1006) tweeter.

The enclosure is .15 cubic feet total, tuned to 75Hz. I used Rustoleum Hammered finish. The crossover is very simple only using four components. Any specific questions please PM me.

264-1006 - Qty 2 - $50.58
299-240 - Qty 2 - $44.00
255-042 - Qty 2 - $9.96
027-334 - Qty 2 - $1.06
027-344 - Qty 2 - $1.48
027-416 - Qty 2 - $3.76
255-200 - Qty 2 - $5.86

Total - $116.70

Matt

[Paul Carmody]

There's those neat little Vifa neo tweeters again. :) No padding needed?

[mattp]

There's those neat little Vifa neo tweeters again. :) No padding needed?

I'm still voicing but honestly no (for me anyway)...I was suprised too. They measured quite wierd in box - if you look at the tweeter FR on the PCD file I attached. All I can figure was the offset on the baffle or some serious baffle step. All in all, they sound very nice, especially for near field. They have a suprising amount of kick too. They're being powered with a DTA100.

[tom_s]

That looks like a great combo. I really like that tweeter. I've had my eye on that Peerless too. I know Lou used them in the BRAPTOR and had good things to say about them. I hope those are still around after X-mas.

[scottsehlin]

I'm a little concerned about the impedance plot It looks like the combination of the very small inductor and rather large cap in the tweeter circuit is giving nearly a dead short across the tweeter terminals at around 7-8 kHz. You might want to consider fiddling with the tweeter crossover a little to see if you can get rid of that - it is probably why you don't need tweeter padding.

[stinems]

If you like the sound as-is, then I can't really argue.

However, I'll point out that your PCD screenshots look as though the speaker offset parameters have been neglected. And in theory, they will be especially important to account for in the PC speaker near-field application because the "flight-time" difference from woofer and tweet to your ear is probably going to cause more problems than if you were listening from 2 meters away. Put another way, a small change in your listening axis could actually count for a lot in freq response while you're so close.

But again, that's all waving-of-hands and foaming-at-mouth on my part. If you're pleased with what you hear, thats all that matters.

Kudos on your driver choices, they'll do you right. Nice project.

Cheers,

Sam

[mattp]

If you like the sound as-is, then I can't really argue.

However, I'll point out that your PCD screenshots look as though the speaker offset parameters have been neglected. And in theory, they will be especially important to account for in the PC speaker near-field application because the "flight-time" difference from woofer and tweet to your ear is probably going to cause more problems than if you were listening from 2 meters away. Put another way, a small change in your listening axis could actually count for a lot in freq response while you're so close.

But again, that's all waving-of-hands and foaming-at-mouth on my part. If you're pleased with what you hear, thats all that matters.

Kudos on your driver choices, they'll do you right. Nice project.

Cheers,

Sam

Sam,

The offset parameters were moot since everything was measured in-box. My seating position is almost exactly on axis to both from about 2-1/2' away so they are almost in the perfect location. I know exactly what you mean about flight-time too...but I'm pretty much stuck in one little spot between my tower PC and drawer cabinet here so theres not a lot of moving around. I also have very few reflections to worry about due to my cubical walls so they have a very 'anechoic' sound to them.

[Wolf]

I'm still voicing but honestly no (for me anyway)...I was suprised too. They measured quite wierd in box - if you look at the tweeter FR on the PCD file I attached. All I can figure was the offset on the baffle or some serious baffle step. All in all, they sound very nice, especially for near field. They have a suprising amount of kick too. They're being powered with a DTA100.

If your impedance is real, it dips to about 1 ohm- not safe for most amps. Care to elaborate?

Later,
Wolf

[mattp]

If your impedance is real, it dips to about 1 ohm- not safe for most amps. Care to elaborate?

Later,
Wolf

Well to be perfectly honest I just missed it. Scott nailed it on the head though (whos post I also missed the first time around, sorry Scott). I'm currently working on another alternative and I'm probably going to shoot for a slightly lower crossover point too. After a couple days of listening I can faintly make out the seperation of the drivers on certain tracks.

[stinems]

Thanks for the response Matt, can't argue with the empirical. Good deal.

Cheers,
Sam

[mattp]

Heres the Xover revamp. Impedance looks much better and only dips as low as about 2.7-2.8 which is the DCR of the tweeter anyway. I'll give ya'll the 411 on the differences when I get them finished up. If you see anything else I missed let me know.

[Wolf]

Heres the Xover revamp. Impedance looks much better and only dips as low as about 2.7-2.8 which is the DCR of the tweeter anyway. I'll give ya'll the 411 on the differences when I get them finished up. If you see anything else I missed let me know.

Personally- I don't like it dipping even that low. It looks as though you need to lose some more sensitivity, roll off your woofer a bit, and padd your tweeter.

Later,
Wolf