a tweeter needed for FE 208E Sigma in a BIB enclosure

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dondiba

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Joined 2007
#1
Hi
i enjoyed my Fostex 208EZ into a BIB enclosure but it definitly lack a tweeter
the one recommanded by Fostex (in the FE 208 EZ data sheet) is way too expensive (about 400 bucks piece)
so what about HiVi Q1r? wich is cheap and 89dB ? or any other suggestion available in europe?
thanks for advice
dondiba
 
#3
planet10 said:
You are best off with a horn tweeter. It will need to be at least as efficient as the FE208eS

dave
Click to expand...

FT17H would be a budget alternative - certainly not as stunningly gorgeous and arguably as elegant a performer as the $400 and up each Fostex supertweeters US prices: FT17H = $38.20, FT96H = $117.70, T90A = $168.30, T900A = $419.20, and T500AMk2 = $810.40 EACH!
 
#6
I would consider the 96H, noting it may need to be tamed a touch to align with the efficiency of the 208, but may not really be noticeable either. I would think the alnico magnet would sound a bit smoother. And the build quality on the 96H appears to be more robust. Of course, this depends on what you would like to spend, and the 17H may be just fine. Seems crazy that you could spend almost $1000 for the top 5-10k of the spectrum. Wow.
 
#7
one1speed said:
I would consider the 96H, noting it may need to be tamed a touch to align with the efficiency of the 208, but may not really be noticeable either. I would think the alnico magnet would sound a bit smoother. And the build quality on the 96H appears to be more robust. Of course, this depends on what you would like to spend, and the 17H may be just fine. Seems crazy that you could spend almost $1000 for the top 5-10k of the spectrum. Wow.
Click to expand...


In the case of the T500A that'd be over $1800 taxes and shipping included. I can think of several very nice wide band drivers selling for less than the sales tax on that amount . In BC, that's12% - in some jurisdictions with the import duties and brokerage fees, etc., that would be even higher. No matter how you slice it, that's a very expensive octave or so, and one would expect something at least occasionally transcendental . Not having heard this exact combination, it's hard to say that wouldn't happen, but I'd be inclined to try the FT96 myself.
 
#9
That Fostex is one of my favorite 8" "wide band" drivers. It does need help on the top although interesting to listen to it by itself.....The top end seems to roll off naturally (no spitting or nasal-ness) so a tweeter blends amazingly well with no low pass needed. I have the original T90, which to my ears is like listening to 400 grit sandpaper being rubbed together to reproduce the highs. At least with a single .47uF cap. A friend has the T500, which kills me because of price and because it sounds so smooth and extended. I've used a couple of compression drivers, either with the back off or from the front, which work quite well. The best I've tried is the Vitavox S2, but is now hard to find I think. The B&C 250 works well, is superior to T90, but is not as good as the T500. I also, ran a conical front horn with a JBL 2410 crossed around 1200Hz and somehow it worked with a lot of dynamic snap (Yeah, I'm still scratching my head on this one and would not have tried it if it was not recommeded by one of the more knowledgeable and senior members of the horn asylum.) I'm going to call my friend now to see if he still has and is willing to part with that T500.
 
#10
Hi Dondiba

I use the 208ez in a horn speaker with the Fostex T90A as my tweeter. You can cross using a 0.47uF capacitor in series, or I am currently running with a 0.68uF cap in series, and a 10ohm resistor across the tweeter terminals. This boosts the upper midrange a little whilst better matching the tweeter to the 208.

I am not fussed with running the 208 full range as there is a nasty peak somewhere in the 4khz range that emphasizes sibilance. If you run it full range with a cap in series with the tweeter i found it worsens the problem. So i have a filter of 0.33mh, 5.6 ohm,2.5uF wired in parallel then wired in series with the 208 driver to act as a notch filter. This produces a more flatter response.

I would suggest you try the filter regardless of the tweeter you use as you may be blaming the tweeter for an issue that resides with the 208. Note, the BIB would likely require a higher inductor (I have heard up to 1.2mH used), and a cap somewhere around 2.2 to 2.7uF depending on your taste. The resistor can also be varied depending on the level of 'cut' youwant.

good luck, Adam
 
#11
#12
KatzMeow enclosure

Hi Norman,

the audax is interresting though not a horn tweeter :
audax gold dome tw 025a28 is at a reachable price, but SPL : only 94,5 Db =
not enought to match that FE 208ez 98 Db

it seems to work however in the KatzMeow enclosure according to the photo on the linked web site but the wording is not about an audax tweeter : Transducer size: 1 X 255mm Fostex transducer & 1 X 87mm Fostex bullet super tweeter.

i send an email to the company for solving that discrepancy
 
#13
true, but the 208ez climbs above 1.5khz. It stays near 94 below 1.5khz then again from 5khz to above.
The Katzmeow from a week ago mentions the audax.
The older meow uses a ff225 (I think) with the fostex bullet.

But the newest KatzMeowV3, I'm in love.
tekton-design2011
true, the lore mentions the audax, but the meow does not.
I wonder what 8" is in there.

I'd bet the MeowV3 sounds better than the lore.

Norman
 
#14
I've been reading a lot lately about some of the frugal horns - especially the Sachiko, Saburo and other Olson/Nagoka style horns. I've become quite obsessed with them actually and I have a newbie question about tweeter augmentation.

It seems like most of the tweeters that I've seen in the horns are the 100+ DB super tweeter type and mounted on top of the cabinet. My question is - can you add a ribbon, dome or other tweeter on the baffle instead? and if so, should the efficiency of the tweeter be as close as possible to the main driver or should it be significantly more efficient?

Thanks.
 
#15
goody75 said:
I've been reading a lot lately about some of the frugal horns - especially the Sachiko, Saburo and other Olson/Nagoka style horns. I've become quite obsessed with them actually and I have a newbie question about tweeter augmentation.

It seems like most of the tweeters that I've seen in the horns are the 100+ DB super tweeter type and mounted on top of the cabinet. My question is - can you add a ribbon, dome or other tweeter on the baffle instead? and if so, should the efficiency of the tweeter be as close as possible to the main driver or should it be significantly more efficient?

Thanks.
Click to expand...


No reason the tweeter shouldn't be mounted on the baffle - in fact they probably work best mounted as closely as possible. They are often added afterwards when using larger diameter wideband drivers that prove to not have adequate HF response for some listeners.

Personally I'd be inclined to a horn loaded type of tweeter of at least the same or higher sensitivity as the wide-bander - it allows for much more flexibility in fiddling with XO points and attenuation if required. In many cases selecting an XO point along the tweeters natural rolloff allows for a simple 1-cap filter . The exact value can be approximated by theory, and tested by paralleling series of cheap mylar caps until the most satisfying blend is achieved, then upgrade to your wallet's content with zoomy boutique types.

Beware that the total cost of some of the super tweeters and spendy filter components can easily exceed that of the mainstream wideband drivers. ( i.e. not Lowther, Feastrex, Fostex limited editions, etc)


and to clarify, many of the enclosures you referenced as "frugal horns" actually evolved from the "spawn" of the original Frugal Horn DIY project, and are designed by Scott Lindgren.
 
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