F200A Cabinets

[ultrakaz]

Hello fellow diyers,

I'm having my F200A Enabl'd by the master Sir Bud P. While waiting I want to build a suitable set of cabs for them. I've searched and found B. Brines cab, LageB Fostex based cabinet @ 47l, 14cm x 8cm port, some comments by J. Kalinowski, and this: http://members.1012surfnet.at/tube.audio/speakers.htm

So, the options are reflex, sealed, t-line or something unimaginable. I'd prefer to keep the size mangeable, since I'm gonna build it.

My inclination is to go sealed, (but why not build the reflex cab and if I don't like it just seal it up.)

Any ideas, comments or suggestions?

Thanks.

[badman]

That's a ballsy move my friend, those aren't cheap drivers!

I just sent Ed Fontaine (sp?) my cash for the EnAbl kit, wonder if I'll notice more change that way than with my rough 'n ready whiteout version)

I'd go with the Tline, is bob's cab a mltl? Nice thing about a tline is the 'evacuation' of the rearwave, they tend to sound less boxy and colored than bass reflex, IMO.

[Scottmoose]

http://homepage.mac.com/tlinespeaker...map-140807.pdf

No mods needed for the F200a. OK, not small. But a simple build. Well, the flat-fronted version is anyway. The second is a trifle harder.

[Bob Brines]

Originally posted by badman
I'd go with the Tline, is bob's cab a mltl? Nice thing about a tline is the 'evacuation' of the rearwave, they tend to sound less boxy and colored than bass reflex, IMO.

My FTA-2000 cab is a 6:1 taper TL and is by no means "boxy"

Bob

[ultrakaz]

Not a "ballsy" move as I've heard the transforming effect of enabl. And the plain F200A sounds like an AM radio with the treble and bass turned up. I did consider using it as a bass driver, but never got around to it.

Thanks Mr. Moose, but I don't get how a cab designed for the FE207 can work for the F200A. Since the FE207 plays several dbs higher in the mids and treble than the F200A, how does the cabinet know to play the bass lower for the F200A? I would guess that there would be too much bass gain and would overwhelm the mids and highs if the F200A is used.

Mr. Brines, I did consider your cabinet as I have read many positive comments about your designs. And I think it would produce better and more bass than reflex or sealed. However, it is a bit large and if I did not like it I could not easily convert it for another purpose.

[Scottmoose]

What you haven't considered is the higher volume compliance & Qt of the F200a. It actually rather likes that volume, which is ironically enough, the same as Fostex themselves suggest for it. Does well with the Pioneer B20 & quite a few other units if it comes to that. It's quite flexible.

I've actually still got some FR plots saved on my PC (I'm without MathCAD at the moment)

Cab. with 207. Ignore the null at 600Hz -it isn't there in practice. LF response is deliberately tailored to look flat -in reality, it's better damped than the sim. predicts due to to some limitations in the software WRT vent aspect ratios etc.

[Scottmoose]

And now with the F200a. For interest only of course -if Bob's TL is too big for you a 5ft tall pair of MTM waveguides isn't likely to appeal.

[Bob Brines]

Vas gets overlooked far too often. For pipes, Vp = Vas is a good starting point. The F200A has a Vas of ~100 l. My TL has Vb = 88 l.

BTW, a QB3 BR for the F200A is ~45 l, although it would be happier is something like 60 l.

Bob

[Scottmoose]

Yep. I'm not usually a big fan of QB3 alignments as a rule, but it should do OK here as the aspect ratio of the throats etc. should kill any potential for booming.

[badman]

Originally posted by Bob Brines


My FTA-2000 cab is a 6:1 taper TL and is by no means "boxy"

Bob

Lookin' sharp there bobby