Fostex FW137 suitable for 2way?

[jazko]

Hello,
since those fostex woofers are discounted on madisound and my cousin wants a pair of speakers, I thought I'd ask for advice.

Is this driver suitable for a 2way and if yes, which HF driver is suitable (I understand that it depends on the budget, but lets say 90-100$ for the tweeters).

Another quick one, is the recommended 0.4 cubic foot tuned to 50Hz is optimal for the driver?

Thanks.

 

[Helmuth]

another quick one LinearTeam

 

[AllenB]

Madisound have a couple of suggestions so it appears possible.

Fostex FW137 5.5" Woofer Shielded: Madisound Speaker Store

 

[Inductor]

Hello,
since those fostex woofers are discounted on madisound and my cousin wants a pair of speakers, I thought I'd ask for advice.

Is this driver suitable for a 2way and if yes, which HF driver is suitable (I understand that it depends on the budget, but lets say 90-100$ for the tweeters).

Another quick one, is the recommended 0.4 cubic foot tuned to 50Hz is optimal for the driver?

Thanks.

Looks like a very nice driver. But like all Fostex you need to know how to take care of them and application to use (it). So, don't rush to much if that type of application and driver is not your bread/objective.

Xmax: 1 mm
Rated Input: 25W

Strassacker: Lautsprecher - Boxen - Selbstbau
recommended cabinet 1:
closed cabinet with 5,3 L volume
from 89/56 Hz (-3dB/-8dB)

recommended cabinet 2:
22 L volume bass reflex cabinet
with HP70 reflex tube, 18 cm long.
from 41/35 Hz (-3dB/-8dB).

 

[mondogenerator]

i have often considered this driver myself, its nice smooth-ish extended roll of makes it appealing to crossover higher than usual, say to a ribbon, or lower than usual to a small conetweeter or fullrange driver.
Thanks for reminding me of this fostex, i was looking for something to go with a neocd1 or mivoc ribbon..

 

[flatfinger]

look at the bottom of the tall boy pdf ; there is a plan for a 10 ltr reflex 2 way .


http://www.fostexinternational.com/docs/speaker_components/pdf/recom_enclose/fw137_fw85k_tboy.pdf


It uses the FT207D ;

Fostex FT207D Shielded 20 mm Dome Tweeter: Madisound Speaker Store


and the
Fostex R80B 100W L-pad: Madisound Speaker Store


track down the remaining caps and coils and start building !!!!

 

[hkingman]

FW137 as full-ranger

Hi jazko,

Building on what Inductor said -- I can share my experience in a very different application...

I use the FW137 full-range, in a 198 cubic inch sealed cabinet.

There's also a tweeter, a 6 ohm, 10mm polymer dome Audax, protected by a 4.7uf capacitor on the + wire:

Audax TW010F1 10 mm Polymer Dome Tweeter: Madisound Speaker Store

The results are ... spectacular. Coupled with the latest SMSL triamp chip amp from Indeed HiFi (on eBay), the stereo image in nearfield applications will literally fill the room.

As a more general purpose bookshelf speaker, this approach is merely okay. There's no problem with volume (though 25W is a ceiling), but some nasal harshness emerges in the lower treble. I believe higher value caps may help. Also, this problem seems to be lessening with run-in (only about 50 hours into the experiment at this time).

Anyhow, if your cousin is looking for some near-field computer monitors, I can heartily recommend the FW137. Pairing it with a higher-quality supertweeter might help the nasal thing, too. If you try it, please let me know how it works out!

Best wishes,

-Henry

 

[mondogenerator]

i think the near fullrange capability of this driver is its appeal, i like the simple approach. I dont like that particular audax tweeter alot, but it isnt terrible if the crossover is high enough..

 

[hkingman]

i think the near fullrange capability of this driver is its appeal, i like the simple approach. I dont like that particular audax tweeter alot, but it isnt terrible if the crossover is high enough..

Yes, the full-range nature... and the small x-mass and low Q torque to push real, tight bass out of a small sealed box... that's magical.

With the Audax tweets, I like the price a lot

I hope to experiment with:
1. rounding off the harsh plastic edges on the diffuser
2. higher cap values to push them into the background a little bit more

One other point.. the fw137 expects to be countersunk. Or maybe you could use a ring under it. Anyway, this adds some build complexity to keep in mind.

-Henru

 

[jazko]

@Inductor - I like the 22L, I think I'll try it for myself in future.

@flatfinger - I can't believe I missed that. I was looking at the other fostex plan using two of the FW137. I Think I'll go for that, as near-field monitors is exactly what my cousin needs. Thank you a lot.

I'll let you know when I start work.

 

[dirkwright]

http://www.madisound.com/pdf/fostexcabs/137_85k_tallboy.pdf

Tall boy... it's a two way.

 

[flatfinger]

A great percentage of the Fostex suggested enclosure pdf's have a intricate folded horn first , then a boring old bass reflex design at the bottom for the less ambitious !!!

 

[planet10]

Fostex suggested enclosure pdfs

An so far have most often proved to be mediocre at best.

dave

 

[mondogenerator]

haha. I would prefer to design my own box, equal lengths in D and W dimensions...never liked that.
The OP asked if the woofer was suitable for a 2way, ive been looking at it as an option for a small monitor.
It would seem able to cross higher than many.
Have you any experience with this driver Dave?

 

[planet10]

Not that particular one. I have heard some of the larger ones in the same family. Very good, normally kind of pricey, but at the special pricing i might grab some myself.

dave

 

[vinylkid58]

An so far have most often proved to be mediocre at best.

Had to model this:

"Works well in 0.4 cubic foot ported box, F3 of 50Hz, 2"vent by 5.5"long."

Works well might be stretching things a bit, if you like a +2dB hump centered around 85Hz. Pushing the box out to 20L gets you a nice flat plot with F3 at 40Hz, almost the same curve as the Alpair 10.2 in the same size enclosure.

jeff

 

[jazko]

Had to model this:

"Works well in 0.4 cubic foot ported box, F3 of 50Hz, 2"vent by 5.5"long."

Works well might be stretching things a bit, if you like a +2dB hump centered around 85Hz. Pushing the box out to 20L gets you a nice flat plot with F3 at 40Hz, almost the same curve as the Alpair 10.2 in the same size enclosure.

jeff

Your simulation is similar to the suggestion of Inductor. Seems like 20L will give best results, yes? What is the port's tuning frequency?

I miight persuade my cousin to abandon the near-field concept

 

[sreten]

Hi,

IMHO an Xmax of 1mm peak turns it into a midrange only driver.

You'd be better off with something like this :
Zaph|Audio - ZMV5 - MCM / Vifa 5" System

And that is no great shakes in the bass department either,
but it should be substantially better, great value design.

rgds, sreten.

 

[vinylkid58]

What is the port's tuning frequency?

44Hz.

 

[Nanuk]

I know this was a year and a half ago, but did anyone ever build anything with the FW137? I have 4 of them and would like to do an MTM with the Fostex FT28D. ANy and all advice would be appreciated.