Design of a TL for Vifa P17WJ

[00940]

A request for critics before starting to cut mdf...

Here's the TL I came with for the Vifa P17WJ. I used MJK's worksheets and the specs for the Vifa P17WJ given by Zaph ( P17WJ and D27TG into a floorstander-advice. ).

- The best simulations results were for a tapered TL with a ratio of 6:1, tuned at 40Hz. The length of the pipe is at 137cm and the driver is offset at 1/5 of the pipe. (see attached picture. At the bottom of the pic, the results for a "classical TL").

- The pipe is folded once and the port is at the back (inspiration comes from the FTA2000 of Bob Brines). Outside dimensions are : 930mm (H)- 244mm (W) - 384mm (D). 22mm mdf used.

- I still have to play with the location of the tweeter.

[00940]

And the box

[Willitwork]

Cool, I was looking for a TL design to use with idle P17's I have at home. What tweeter do you have in mind for the project?

[00940]

Tweeters will be the D26TG-05-06.

[Willitwork]

Originally posted by 00940
Tweeters will be the D26TG-05-06.

Shucks, those are discontinued and even though Solen lists them they are no longer available.

[MJK]

Ben,

This being said, no short comment on the speakers ? Nothing obvious to take care of ?

The design looks good, I like tapered TL enclosures. The only concern I have would be how you plan to handle the baffle step issue. The second set of calculations in the worksheets should help determine how the frequency response will look. Have you run those calculations and can you post the SPL response?

[00940]

To be fully honnest, I intended to use a serie crossover developped for the same drivers but for a double BR enclosure, with the same baffle width. The BR enclosure is just slightly less deep and high. The design is well known and tested on french boards. http://audioclone.free.fr/new%20baby.gif

[MJK]

I am not sure, I don't know much about series crossovers, but it may be that the 6.8 ohm and 30 uF leg in parallel with the drivers and crossover provides the baffle step function. But the bottom line really is if it is already a designed and tested crossover for these drivers you should be all set.

[Willitwork]

Originally posted by 00940
To be fully honnest, I intended to use a serie crossover developped for the same drivers but for a double BR enclosure, with the same baffle width. The BR enclosure is just slightly less deep and high. The design is well known and tested on french boards. http://audioclone.free.fr/new%20baby.gif

He he he what a coincidence, I have built the ASA Baby clone over the last month, with the parallel crossover. It sounds surprisingly good. Unfortunately I have no idea what Vifa model "HT 270" is and googling it yielded no clues so I used the D27-35.

http://audioclone.free.fr/asababy.html

Not being sure if the driver I'm using is the one the crossover was designed for bugs me a bit though. Id there any way of finding out what the model numbers Vifa uses in France and the Netherlands (those are the countries with alternative model numbers that I'm aware of, there are probably more) correspond to in, say, the Solen and Madisound catalogs?

[00940]

MJK : thanks. I'll let you know how this thing ends

Willitwork : John Kreskovsky published a crossover for the P17WJ and the D27TG : http://www.audiodiycentral.com/sd200_johnk.shtml

I prefer to use the serie crossover from Aldo (audioclone.free.fr) as it was designed for and tested on a bigger box, with a baffle more similar to mine.