The Winged Voigt Pipe - Good for Nothing?

[rjbond3rd]

I've seen images of so-called Voigt pipes circa 2004 modded to have baffle wings (on piano hinges) similar to the wings on OB's.

Is there any reasonable scenario in which the LF from the driver-plus-wide-baffle sums nicely with the LF (such as it is) from the horn mouth? Or is this just a terrible mess?

Or stated another way, is it sane to try to strengthen the bass from what is essentially an OB design by slapping a tapered pipe on the back?

(Why bother with this? Long story, but I can't quite accomodate BiBs which would I realize would be a much better approach...)

I suspect this design must be deeply flawed -- i.e., you just can't correct a so-called Voigt pipe with an OB-esque wide baffle, and vice-versa -- since the design is no longer popular. I guess I'm wondering what the flaws are. (I did search the forum for answers, and I'm definitely aware that this so-called Voigt pipe is sub-optimal, though OB seems well regarded, hence the question.)

Thanks in advance for any insights!

 

[Scottmoose]

Well, there's nothing wrong with a properly designed (ML) TQWT. It's just that the Lowther Club of Norway Voigt Pipe cabinet isn't -it doesn't appear to have been optimised for anything in particular. As is, extension is mediocre & response somewhat ragged higher up due to the lack of supression of harmonic resonances.

What driver did you have in mind?

 

[rjbond3rd]

Thank you for your reply, sir. I did see unfavorable references to the design, but also noticed that nearly every builder seems to have omitted the wings without comment.

The drivers are Fostex FE207e (should have mentioned that). Thank you in advance! I really appreciate it.

 

[Scottmoose]

That's because the wings haven't been omitted -very few people have seen that variation, which, IIRC, is linked to from Lowther US. They'd be useful in lowering the baffle step point, & if you like the wavelaunch from wide-baffles.

Anyway, if you want a VP for your 207s, here's one. I even kept the WxD dimensions at the base for you.

Internal: 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.

 

[rjbond3rd]

WOW, I am speechless. I only thought someone would give me a friendly shove in the basic direction.

Thank you very much Scottmoose -- that is a very reasonably sized enclosure in my mind. The center of gravity will be much lower than a BiB (less likely to tip over onto my son or wife, and half the weight if *gulp* it ever did).

Mucho appreciamente, senor -- I'll post pictures if my "woodwork" isn't too hard on the eyes!

 

[rjbond3rd]

I have to add -- wow, that is a phenomenal FR. It's only about 10Hz shy of what a BiB would do (just looking at the graphs simplistically).

On my own, I would have probably managed 80Hz through trial and error. Thank you for that extra octave! From me, and the cello.

 

[Scottmoose]

You're welcome. They'll probably need a BSC circuit if pulled out into the room, less so if near a wall. YMMV. You can tailor the LF response by adjusting the damping once in-room. If you build them, do let us know how things progress.