Can it be? FW127, FW187

[badman]

Cones without breakup at all? Anyone measured the FW127 or FW187 from Fostex? Check the Datasheet:

http://www.fostexusa.com/support/pdf...data_sheet.pdf

http://www.fostexusa.com/support/pdf...data_sheet.pdf

Where's breakup? High frequency directionality? Are these the perfect linear driver?! Or is fostex (usually not bashful about displaying off axis ripple) fulla bologna?

[Scottmoose]

I believe it's called 'smoothing.'

[badman]

Sure there's smoothing but smoothing doesn't improve dispersion at 6kHz to be better than many dome tweeters, you'd still see averaged pattern narrowing (and typically breakup too, even with pretty heavy smoothing).

Of course they can't be as nice as the sheets show, but perhaps they do have superb dispersion and linearity, need to see independent numbers to ever be 100% certain where the buck stops.

The last word of my post was 'bologna', 'cause DIYAUDIO rules forbid using the words to describe what these figures smell of

Let's just say that Paul Wilbur Klipsch might have a yellow button for them.

[BHTX]

Those off-axis plots make no sense whatsoever.

[Graham Maynard]

Cone not lightweight and dust-cap glued to cone *not voice coil* so response starts falling circa 7kHz.

X-max suggests overhung voice coil with increased impedance and cone/cap preventing substantial driven peak before roll-off.

Not widerange, but not claimed to be either, so probably a reasonable performer with simple crossover and tweeter.

Cheers ........ Graham.

[chrisb]

Originally posted by Graham Maynard
Cone not lightweight and dust-cap glued to cone *not voice coil* so response starts falling circa 7kHz.

X-max suggests overhung voice coil with increased impedance and cone/cap preventing substantial driven peak before roll-off.

Not widerange, but not claimed to be either, so probably a reasonable performer with simple crossover and tweeter.

Cheers ........ Graham.

I'd certainly concur with that - I have a quad of an earlier driver from the same series ( FW227) that were purchased at a clearout price from Madisound, circa 2003.

Gorgeously made, and great value in a midwoofer for the price (AFAIC, about $70) - work very well in a bipole mini-tower, originally with Heil AMT, simple 1st order on each.

[bananaslug86]

Originally posted by chrisb



I'd certainly concur with that - I have a quad of an earlier driver from the same series ( FW227) that were purchased at a clearout price from Madisound, circa 2003.

Gorgeously made, and great value in a midwoofer for the price (AFAIC, about $70) - work very well in a bipole mini-tower, originally with Heil AMT, simple 1st order on each.

Chris, how did those speakers sound? I have a pair of Heil AMT II speakers that I wanted to use for that sort of project. Were they worth the effort? They certainly look nice enough, although I am getting partial to the AMT pyramid.

[chrisb]

The AMT driver can be as frustrating to work with - they're capable of magically fast and transparent upper mids and top end - (too revealing in poorly designed or integrated systems), but more importantly, integrating with mid/bass drivers "fast" and clean enough is the funnest part.

Are they worth the effort / expense? If you already have the drivers / cabinets, I'd definitely go for it.

A previous project was a re-build of literally falling apart pair of original AMT1 boxes, and incorporation of Emminence 6" midrange. As you can see that necessitated a rather more elaborate XO than you can get away with in a 2-way.






http://homepage.mac.com/tlinespeaker.../heil_3way.jpg



FWIW, the original factory XO for the AMT1 was a joke - very poor quality parts & assembly, and with a completely unnecessary presence boost control. I'd trash them altogether, put a simple HP protection film cap on the AMT (say around 800Hz) and bi-amp with something like a Behringer XO or even PLLXO. I'm personally a fan of SET (e.g. 2A3 / EL84) on the AMT, and either P/P EL84 or EL34 or even some of the new class D / T amps on the bass.




The performance of the stock woofer and PR are actually quite respectable, but the cabinets could definitely benefit from additional bracing (or with the drivers removed, assisted combustion)

[badman]

Originally posted by chrisb



I'd certainly concur with that - I have a quad of an earlier driver from the same series ( FW227) that were purchased at a clearout price from Madisound, circa 2003.

Gorgeously made, and great value in a midwoofer for the price (AFAIC, about $70) - work very well in a bipole mini-tower, originally with Heil AMT, simple 1st order on each.

Nice work. Did you run any tests? How did you find the off-axis of the fostex?

[chrisb]

Badman - sorry no tests - the XO was somewhere about 3000-3200Hz, and my with a few degrees of toe-in, my central listening position was not far off axis.

I'm sure accurate in-room measurements of these would find disapproval by many, but since I'm doing the listening, I can afford to not care about that.


In the previous project with the 3-ways, the drivers were individually measured in the cabinets, and the XO's designed with LEAP/LMS system - the results looked good on paper on the monitor screen, but the sound was a bit too flat for my taste.