okay, first listen.
alrighty, got a box together. i'll post pix later.
started with the suggested 3oz. of acoustastuff behind the fe166. driver frame damped with aforementioned sheet material. mounted with rope caulk. all cabinet joints puttied and smoothed, a piece of moving blanket on the back wall directly behind the driver. some damping sheet on the biggest box surfaces.
hooked 'em up to a carver ss amp with 50 ohms across the terminals, and dug up 6.8mf black gate and 20 ohm resistor for a compensation network.
the sound is quite smooth and extended. no need for tweeter on axis but i may end up adding one depending on listening position.
my only complaint at this point is:
sound emerging from the terminus sounds kinda out of phase with the direct sound emanation from the driver. there is significant midrange output so i may stuff the line a bit to see if that helps the situtation.
speaker is very directional in the HF so if these are placed on the flor, which seems a must for solid bass, they may need some help from a tweeter for good HF dispersion.
any comments re: those two points?
BTW...
as i was listening a kid walked in to my shop to pick up his guitar amp. the velvet underground was playing.
he did a huge double-take. triple take really.
"is that ONE speaker???"
hahahha
alrighty, got a box together. i'll post pix later.
started with the suggested 3oz. of acoustastuff behind the fe166. driver frame damped with aforementioned sheet material. mounted with rope caulk. all cabinet joints puttied and smoothed, a piece of moving blanket on the back wall directly behind the driver. some damping sheet on the biggest box surfaces.
hooked 'em up to a carver ss amp with 50 ohms across the terminals, and dug up 6.8mf black gate and 20 ohm resistor for a compensation network.
the sound is quite smooth and extended. no need for tweeter on axis but i may end up adding one depending on listening position.
my only complaint at this point is:
sound emerging from the terminus sounds kinda out of phase with the direct sound emanation from the driver. there is significant midrange output so i may stuff the line a bit to see if that helps the situtation.
speaker is very directional in the HF so if these are placed on the flor, which seems a must for solid bass, they may need some help from a tweeter for good HF dispersion.
any comments re: those two points?
BTW...
as i was listening a kid walked in to my shop to pick up his guitar amp. the velvet underground was playing.
he did a huge double-take. triple take really.
"is that ONE speaker???"
hahahha
jeremyg said:
sure, why not!
actually i've been buying the larger sheets at dealer prices...note that this material is not asphalt based, they claim 2X the damping of asphalt which is a lot cheaper...
actually this particular cab needs very little damping. it's quite rigid and the speaker is very damped so it hardly excites the cabinet at all..
Damp the first bend.
The mid range coming out is part of the problem. This is smearing the sound. Normally the bend will take care of most of this. Try lining the first fold on the outside wall with a thin dampening material.
The best I found was an adhesive backed foam from American Surplus. Felt from Home Depot works almost as well. Just try the green thin sheet felt to absorb the midrange in the bend.
I am a fan of the A series Lowthers. With even the PM6A there is plenty of high end extension to my almost 50 year old ears. The PM7A and PM2A are just a little better.
All the Fostex tried and listened to have much better published specs, but I do not hear the top end. I hear another octave on top with the 15 ohm Alnico Lowthers.
I my latest 5' tall folded TQWT the measured in room is good to 25 Hz. The -3bd is 35 Hz. This is plenty for the music listened to.
After driving them for 10 years with tube, I now only use class A solid state. Alephs, Le Monstre, and the like. Controls the bottom and top better than even OTL.
George
noisenyc said:
The mid range coming out is part of the problem. This is smearing the sound. Normally the bend will take care of most of this. Try lining the first fold on the outside wall with a thin dampening material.
The best I found was an adhesive backed foam from American Surplus. Felt from Home Depot works almost as well. Just try the green thin sheet felt to absorb the midrange in the bend.
I am a fan of the A series Lowthers. With even the PM6A there is plenty of high end extension to my almost 50 year old ears. The PM7A and PM2A are just a little better.
All the Fostex tried and listened to have much better published specs, but I do not hear the top end. I hear another octave on top with the 15 ohm Alnico Lowthers.
I my latest 5' tall folded TQWT the measured in room is good to 25 Hz. The -3bd is 35 Hz. This is plenty for the music listened to.
After driving them for 10 years with tube, I now only use class A solid state. Alephs, Le Monstre, and the like. Controls the bottom and top better than even OTL.
George
Re: Damp the first bend.
yes i think you are dead on, daddy-o
midrange reflection within the horn is making it midrange-heavy....i am def hearing a lot of 1.5k energy i'd like to reduce.
i'll try foam or felt on the walls at the bends first...if that don't do the trick, perhaps i'll add some very light stuffing in the bendy bits..
Panelhead said:
yes i think you are dead on, daddy-o
midrange reflection within the horn is making it midrange-heavy....i am def hearing a lot of 1.5k energy i'd like to reduce.
i'll try foam or felt on the walls at the bends first...if that don't do the trick, perhaps i'll add some very light stuffing in the bendy bits..
while dampening the frame is a laudible goal, a F A R more important goal is to dampen reflections from the frame and motor assembly.
You can achieve both requirements to a degree with the material I propose, BUT its purpose if more oriented to reducing reflections.
(CAE does make the premaid stuff for the job, and is available at PE - but its a bit pricey for the volume.)
This is the link I'd suggest (the original, and in the "mix-it-yourself" version its use if more flexible):
http://www.hytechsales.com/insulating_paint_additives.html
(to see prices scroll to the bottom and click "buy now")
You can achieve both requirements to a degree with the material I propose, BUT its purpose if more oriented to reducing reflections.
(CAE does make the premaid stuff for the job, and is available at PE - but its a bit pricey for the volume.)
This is the link I'd suggest (the original, and in the "mix-it-yourself" version its use if more flexible):
http://www.hytechsales.com/insulating_paint_additives.html
(to see prices scroll to the bottom and click "buy now")
The BK16 has a small - nearly nonexistent - rear chamber. It's designed to work well into the midrange, which is why it's the recommended horn for the FF165. The FF165 needs some help in the mids to match its output from ~2k-10k.
The recommended horn for the FE166 uses a much larger chamber for a lower crossover point.
If at all possible, chiseling out some more space behind the driver in the BK16 should help attenuate the mids. Some of that doubled baffle could be routed away. Might be tough if it's glued together already... Some more stuffing back there should have some of the same effect, as would shimming the throat a bit smaller.
GB
The recommended horn for the FE166 uses a much larger chamber for a lower crossover point.
If at all possible, chiseling out some more space behind the driver in the BK16 should help attenuate the mids. Some of that doubled baffle could be routed away. Might be tough if it's glued together already... Some more stuffing back there should have some of the same effect, as would shimming the throat a bit smaller.
GB
Greg B said:
hmmm. i thought madisound chose the ff165 to put in that horn and not fostex. at least that's what the madisound website says...
as i understood it, the bk-16 is a general purpose enclosure for a number of fostex drivers...jack of all trades master of none.
here's the full-on fostex 166e recommended enclosure:
http://www.fostexinternational.com/docs/speaker_comp/pdf/recom_enclose/166e_enclrev.pdf
they recommend reducing the back chamber size if you prefer "tighter" sound, and filler to reduce midrange output from the horn mouth.
i'm going to stuff it more and see what happens.
meanwhile, i hooked it up to an audio note PSE 6L6 amp somebody stiffed me with (!) and plugged in my ipod to it for some break-in play.
it was giving me chills with lefty frizzell.
it does not need a tweeter, no way no how.
i'm gonna get those midrange reflections down a bit and get some "box volume" with acoustastuf, and listen to music.
FWIW, the FF series info sheet that came with my FF125K's listed the BK16 as the recommended enclosure for the FF165. Can't say as I blame you for picking the FE166 though. And the recommended horn for that looks a bit too long, as if they're trying to squeeze too low an F3 out of it.
So yeah, try another handfull of acoustastuff and listen to the music... Fostex drivers really do break in, BTW. All the ones I've had have mellowed considerably after a couple weeks.
GB
So yeah, try another handfull of acoustastuff and listen to the music... Fostex drivers really do break in, BTW. All the ones I've had have mellowed considerably after a couple weeks.
GB
Greg B said:
i've been leaving it on overnight with some 20hz going thru it...it has changed considerably since i first mounted it. better and better. i'm not gluing on that cabinet side for another couple weeks haha
the fostex cabinet design process seems an arcane art. lots of wiggle room. i vaguely remember seeing a fostex published list of recommended drivers for the bk-10 and bk-16 cabs on the EIFL website a few years back...i'll look on my sheet to see if the have any more cabinet info...haha now i'm curious.
it's a darn fun listening experience for the dough i must say.
here is the fostex catalog page that suggests the various drivers for Bk-10,Bk-16 & bk-20...
www.fostex.co.jp/jpn/CATAROGUE/CATAROGUEpdf/hifi/enclo.pdf
If someone knows how to get BK-20 in north america let me know.
cheers
Paba
www.fostex.co.jp/jpn/CATAROGUE/CATAROGUEpdf/hifi/enclo.pdf
If someone knows how to get BK-20 in north america let me know.
cheers
Paba
Yeah, based on what they charge for the BK-16, if they charged a few bucks more for the BK-20, I would consider putting FE206E into them.
Or what they could do possibly do is sell the cut-out plans for the Bk-10, BK-20, for 25$ each if they don't plan to sell the cabinet flatpacks.
Cheers
paba
Or what they could do possibly do is sell the cut-out plans for the Bk-10, BK-20, for 25$ each if they don't plan to sell the cabinet flatpacks.
Cheers
paba
[SIZE=3]stuffing, schmuffing..[/SIZE]
stuffing, schmuffing.
i put some more stuffing in that fostex horn and listened.
ew. it was, like totally, killed to death.
no highs. no lows. just flat 2-d plane of midrange spewing from its ugly face. very little output from the mouth at all.
i lightened up the stuffing in the chamber, added a very thin teased up puff in the first bend to filter some mids from reaching the mouth.
death. no lows.
just for kicks, removed ALL stuffing from the box. just a thin moving blanket behind the driver, and some flat polymer damping sheet on the larger unbraced surfaces.
much much MUCH better. alive again. resonant, yes, but in a pleasing way. not obnoxious, not dead. still a bit hairy with the midrange, but not too bad...
the other day my pal jc and i were talking about how a lot of manufacturers are using tons of partitions in cabs with lots and lots of holes, to basically create so many reflections within the cabinet that none predominate...the sort of oppostie approach to making a very dead, damped cabinet.
then i was thinking about those fostex hp sound reflector thingies.
http://www.madisound.com/fostexaccessories.htm
aha.
aha?
anyone ever try making something like this?
stuffing, schmuffing.
i put some more stuffing in that fostex horn and listened.
ew. it was, like totally, killed to death.
no highs. no lows. just flat 2-d plane of midrange spewing from its ugly face. very little output from the mouth at all.
i lightened up the stuffing in the chamber, added a very thin teased up puff in the first bend to filter some mids from reaching the mouth.
death. no lows.
just for kicks, removed ALL stuffing from the box. just a thin moving blanket behind the driver, and some flat polymer damping sheet on the larger unbraced surfaces.
much much MUCH better. alive again. resonant, yes, but in a pleasing way. not obnoxious, not dead. still a bit hairy with the midrange, but not too bad...
the other day my pal jc and i were talking about how a lot of manufacturers are using tons of partitions in cabs with lots and lots of holes, to basically create so many reflections within the cabinet that none predominate...the sort of oppostie approach to making a very dead, damped cabinet.
then i was thinking about those fostex hp sound reflector thingies.
http://www.madisound.com/fostexaccessories.htm
aha.
aha?
anyone ever try making something like this?
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