Dark Vador speaker!, test version

[gychang]

I had a 8" Pioneer and tweeter in the garage and noticed scraps of wood... I wanted to try older design and came up with Dark Vador (also had flat black paint at hand). Using the new tweeter here : Parts-Express.com:*Dayton ND20FB-4 Rear-Mount 3/4" Neodymium Dome Tweeter | tweeter nd20fb-4 soft dome tweeter dome tweeter neodynium dayton audio dayton loudspeaker dayton zdt35-60608 POTT-080108 DayAudiTweetWoofMid050109, using 2uF Capacitor. Voight Pipe vent size was estimated at 8" and overall sound is good. Tweeter seems to match well with the pioneer. Lower bass sounds good but not quite right to my ear after listening for little over one hour.

In near future I want to put the combo speakers in a real cabinet (3/4" plywood) with a nice stain. Can someone give a perhaps different vent size using the 8" Pioneer? I can tell these 8" Pioneers are more dynamic in a larger room than the 4 1/2" Pioneers that I am used to. If you don't mind a larger cabinet, the Dark Vador is a worthwhile build.







gychang

[picowallspeaker]

Putting speakers in the middle of the cabinet should be avoided. Or not ?!?

[just a guy]

Going on looks alone, I'd guess that those enclosures are way too small for the Pioneer B20 and tuned very high, especially because of the horn shape. I'd be surprised if there was any low bass at all. Also, the bass driver looks like it's too low. Usually the driver would go at .2 or .4 x line length (from the closed end) to smooth out the response.

Check Godzilla's BOFU BIB page for an idea of how big of a box the B20 wants if you want to use this Voigt style shape.

[Bob Brines]

And my first guess is that the vent is WAY too big. You need to model this thing to get an idea what the vent should look like and exactly where the driver needs to be placed.

A "Voigt Pipe" can be made to work reasonably well with the right driver, but I don't think that the Pioneer is it. I could be wrong, though. Again, you need to model it to find out.

Bob

[gain-wire]

Oh good GOD,
I can't believe this. Painted Aspenite whacky cabinets mated to a fullrange speaker? That's not HIFI, dude.

But I'll give you two thumbs up for the styling, it reminds me of old SPICAs.

[tinitus]

Originally Posted by gain-wire

But I'll give you two thumbs up for the styling, it reminds me of old SPICAs.

pure diy

I remember some of my tweeter horns made from plastic bottle necks
And lots of not calculated horn designs
And they were certainly no worse than any proven design, at the time
It was pure fun

This was the only available quaterwave, and used with any avaiable 8" by many of my friends, 40years ago
Really shined with RichardAllan and ST70 tubeamp

[gychang]

Originally Posted by Bob Brines

A "Voigt Pipe" can be made to work reasonably well with the right driver, but I don't think that the Pioneer is it. I could be wrong, though. Again, you need to model it to find out.

Bob

I am not electronic/math type of guy...

gychang

[rjbond3rd]

Hi Gychang,

If you want to see some optimal dims, Scottmoose was kind enough to calc me these some time ago (for the FE207E). Maybe these can shed some light:

The Winged Voigt Pipe - Good for Nothing?

[gychang]

Originally Posted by rjbond3rd

Hi Gychang,

If you want to see some optimal dims, Scottmoose was kind enough to calc me these some time ago (for the FE207E). Maybe these can shed some light:

The Winged Voigt Pipe - Good for Nothing?

that link is very helpful, thanks,

gychang

[gychang]

Scottmoose suggest following for FE207, which I understand is similar to B20.

"66.6in x 8.75in x 8.75in (at base), comes to a point at the top as per usual. Driver centre 32in down. Vent = 4in diameter x 4.5in long, centre 2.5in up on the front or rear panel. Stuff 0.4lbs ft^3 of dacron / whatever from the top 40in down"

Mine is bigger at base: 8 1/2"x11 1/2", with the height of 74". I have the vent on the bottom apparently 8" of vent height is too large. Can someone let me know what the vent size should be?

gychang