Supravox 215 and backhorns

[jsb]

Dear all

I do not have enough room here to try the supravox 215 in OB (it needs about 2 meters from the wall to give its best) and I was wondering if it made sense to try and tweak one of the nagaoka or fostex (the 208??) enclosures for this driver?

From what I gather from the web, trials with the "universal" MJK MLTL needed a lot of tweak, so I was wondering if a good BLH would not be able to give a fine tonal balance?

Any hint concerning enclosures will be appreciated!

[Scottmoose]

Which 215 do you have? There's 3 of them, all with different claimed parameters & we don't want to make a mistake.

[jsb]

Sorry, it's the basic one, the regular 215RTF64

http://www.supravox.fr/haut_parleurs/215_RTF.htm

[Scottmoose]

I'll get my thinking cap on. There'll be something interesting we can do with it no doubt.

[xcortes]

I have the 215-2000 exc on open baffle and they're about 1 meter from the rear wall which, if my calculations are correct, is only 1/2 of the 2 m you say they need. I'm seated at about 3 m from them. I don't think they can sound better. OTT you could try the Supravox recommended tqwt. There's good reports on that one too. Here's the link:

http://www.supravox.fr/kits/tqwt215.pdf

[el`Ol]

Search for the "Amygdala" at audiodiskussion.de. This is a nice hybrid between OB and Box.

[fred76]

H jsb,

Here's what Scottmoose generously gave me offline for the non-bicone RTF64 Straight-MLTL:

Here's a rough one (internal dimensions):

42in line length
12.5in deep
16in wide
Zdriver 8in
Port 4in up from base; 4in diameter, 1in long.
0.25lbs/ft^3 stuffing in the first 30in. = .868lbs. Total


Bracing following Scott's 'swiss cheese' approach using the golden ratio cross-section.

I haven't built it but I have no doubt it would sound great... *thanks Scott!* Attached below is the Mathcad response he sent me.

fred

[jsb]

Hey

Thanks to all!! I was thinking of a BLH as I

- need to have something "manageable" (no 1,70*1,70m thing)

- wish to avoid implementing BSC

But the Qts is of course devised for OBs.

I'd be glad to try the MLTL but I'm worried with the correction issue (it would be a pity to waste my KR842's 7 watts in a passive filter). I have now, running on my system, a couple of FE207 DBRs; they're quite good, and have more bass than enough, but the DBR enclosure reduces the efficiency, and the supravoxes are way smoother for voices.
There's no hurry, but having the drivers, I want to make sure I've something to build during the next break, in spring or summer.

jsb

[mantistube]

I don't mean to change the topic but could anyone of you Supravox users tell me about their sound? It is so hard to get information on these French drivers. Even in Paris i was unable to get an audition on this or the Fertin. PHY-HP where great but i really wanted to hear a modern field coil.

Back to the issue the field coil sound does anyone have an issue with beaming or being restricted to one type of music. Trying to justify trading my rebuilt QUAD 57'!

Thank you all, this is a interesting thread!

[Scottmoose]

Got an idea. You could try dropping them into the Viech chamberless horn. If you're worried that the volume isn't great enough, boost the width to 300mm rather than 250mm. Could be interesting anyway.