first diy build

[rv1890]

Im looking to build either the

http://www.zaphaudio.com/audio-speaker17.html
or
http://www.zaphaudio.com/audio-speaker12.html

The only problem is how can I build my own cabinet for these??
Zaph uses the parts express cabinet kit.
I can get the dimensions for the cabinet that zaph uses off of parts express, but what about the port? Do any of these models have a port on the rear??...or are they sealed??.
My eagar to start...thanks guys.

[Cal Weldon]

I believe the cabinets are all sealed and you will have to add the port yourself as they appear to have only the binding post holes on the rear.

Here's from the PE site for the 0.38 cu ft unit:

"Constructed out of 3/4" MDF with real wood veneers, the quality of these cabinets is outstanding. Each cabinet has 3/4" side and back panels with a 3/4" MDF "shelf" brace running vertically up the sides and across the top and bottom. The baffle is 1" MDF with a black satin finish and rabbeted construction. The rear of the cabinet features two 1/4" holes allowing the simple installation of our knock-in binding posts (#091-1245). The overall cabinet is extremely rigid and solid, with minimized panel resonance."

[herm]

From the Speaker 12 page:

The enclosure was one of the new models at Parts Express, part number 302-712.
The port I used was a Parts Express 260-402 1.5" flared port. It's closer to 1-5/8" diameter, and about 4.2" long.

From the speaker 17 page:

This system is designed to be used in a .5 cubic foot Parts Express pre-fabricated enclosure. I selected a tuning of 42hz

The port was made up of several Parts Express 260-402. It's a flared 1.6" port which seems kind of small, but I took 4 of them and cut each one to 2.2", then taped them together for a 4.4" total length. This gives me a flare on the inside, and lets me get away with a small port without turbulence problems. The flares on both ends also make it less prone to organ pipe resonances. I placed it behind the tweeter. If you'd like to use a different port diameter, figure the length out for yourself using the real T/S parameters, WinISD, a tuning frequnecy of 42 Hz and a box size of .50 cu ft (14 liters)

I followed Zaphs directions by downloading WinISD, and came up with a port about 5 cm (.047 m)across and 17 cm (.173 m) long.

Someone double check that port length calc I did please.

[wa4swj]

Late response I know ----

I just finished two of Zaph's Speaker 17 designs last night. I used the port just as described and built them just like in the pictures except I used birch instead of cherry cabinets from Parts Express. These speakers are awesome. That's all I can say. A lot of bass, clean output, balanced and so on. I am very, very happy with them. This was my first serious speaker building project and I can heartily endorse the design. Others have probably built them too.

I'm driving them with a Dynaco ST-70 clone I built. Wonderful sounds.

Best regards and by now you've probably built something.