Fostex F200A vs Visaton B200

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I intend to make a pair of reflex speakers using a full-range driver, and have identified the Fostex F200A and Visaton B200 as likely candidates. I would be interested in views on these drivers, and which is best.

Domestic considerations limit the box size to 920mm high, 230mm wide and 300mm deep. Allowing for an 18mm wall thickness, gives an internal volume of about 45 litres.
 
They aren't anything special -just a heavily damped double bass reflex, a bit like the cabinet Fostex have on their site for the FE207E. No time to model them tonight, but I'll have a look in the morning. Heck of a complicated circuit they've put on them too. Personally, I'd build something like a 70 litre aperiodic cabinet for them, or stick them on an open baffle, which is what they were really designed for.
 
from having read about the f200a and vistaion b200,

I would recommend the fostex unit. expect an better all around driver.

the alnico is beastly too....if only for that reason, go with the alnico.

expect a different sonic aesthetic than the banana plant fibre stuff. a perceptible flat response should come from these. along with very high speed. the bump at 5k I would consider to be fairly negligible considering the flatness in the rest of the spectrum. what looks like just a dinky foam surround I am pretty sure is rubber impregnated, at least it was on the fx120 that I played with for a while.

the fx120 is a nice driver, would be a goood studio monitor. the f200a should be totally killer.

but I have heard neither.

only about them.

Clark
 
Thanks for all the useful feedback.

The measured response of the B200 does look a bit alarming, with that wobble in the mid-band, and rising response.

I reckon my intended cabinet dimensions would just about support a conventional quarter-wave transmission line, if tapered and stuffed. Any experience of the two drive units in a TL enclosure ?
 
The B200 is a lovely unit, but it's really designed for use on open baffles, hence the high Q etc. It'd work in a traditional TL, but the thing would have to be huge to provide sufficent Vb -it's not just about line length I'm afraid; cabinet volume is vital. And the B200's Vas is a high 102 litres. Personally, I'd just build Bob Brines's TL for the F200a (FTA 2000) or one of the several MLTL designs for this driver lurking around the 'net. That's about as good as it gets for a relatively compact enclosure. It's probably a little bigger than you want, but there's no free lunches in audio -high Vas means big cabinet if you want bass.

If you want to use the B200 in a cabinet, an aperiodic loading is best IMO. A TL can provide the same sort of response, or go lower, but as I say, it will need to be a fair bit larger than this to match the extension, and absolutely huge to beat it.

Internal dimensions: 38in tall, 9in wide, 12in deep. Stuff the whole cabinet with a density of 0.5lbs ft^3 of Dacron or similar. Centre of the driver wants to be 8in down from the internal top. You can either rout a slot near the base of the cabinet (wherever makes you happy) & damp it to taste, or use two of those Scan Speak Aperiodic vents (I'd suggest the rear of the cabinet) which will make it fractionally under-damped, and adjust the density of the internal stuffing behind them. The latter look nicer, but they cost about $8 apiece, while routing a slot in the cabinet is free. Response is attached. As you can see, it doesn't go especially low. Should sound pretty decent though, with a suitably 'fat' bass. You can flatten it by cramming more stuffing into, or behind, the vent
 

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I have the F200As running in 45 liter ported cabinets.

I am building Bob Brines' FTA-2000 cabinet, and will transfer
them as soon as the TLs are done.

So far, so good. More bass than I expected, and I don't think
I will need a super tweeter (although my high frequency
hearing is limited.

Here is the Unibox model I built.

Unibox Model

herm

Edit: Why can't I link to a picture? Too stupid I guess....
 
greetings Ladies and Gentlemen, I personally haven't heard the f200A but I have built two pairs of horns using fostex 206 and 103 and am now using b200 in open baffle.I think tomek summed it up beautifully regarding the Japenese and German drivers. Do you want to ride a Kawasaki that when it hits the powerband is insanely fast and responsive or do you want to ride a BMW with the smooth opposed engine and comfort ride. Horses ffor courses but I find the Visaton a great antidote to the highly articulated and mid forward fossies which on first listen I always found exciting but ulltimately fatiguing and tiring.I'd literally get irritated after an extended listening, while the B200 coupled with a sub crossed at 150hz gives me great detail, phenominal sounstage and yet a relaxed presentation that I can listen to all day long. As Howlin Wolf once sang " i was built for comfort, not for speed"
peace and goodwill
cheers Fergs
 
While it does not meet the criteria stated initially, I am using a B200 in the Solo 20 and find it be very enjoyable. They are small and I can carry them to whatever room I want in the house to listen to them. I listen to them all day while I watch football on Tv. They seem to like Tangerine Dream as much as I do.
Howard
 
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