Brines Acoustics


Last Modified 12/29/16


Fostex FF165WK Mass-Loaded TL

The M12-F165 represents the continueing evolution of my six-inch driver line. This particular iteration was forced upon me when Fostex discontinued the FE167E driver that I had been using for the last ten or so years. After some searching, I found that the new Fostex FF165WK will work in a MLTL type cabinet. The resulting cabinet is 2" slimmer in depth. It turns out that the overall sound is even better than the FE167E. The highs are more extended and there is a dip in the 1000-3000Hz range that gives a nice, mellow sound. The bass doesn't go quite as deep, but plenty deep to cover all acoustic instruments.

As with all of my floor-standing speakers, the primary resonance of the cabinet is a quarter-wave mode. This speaker is designed to reproduce the more intimate genre, Baroque and early classic, jazz trio and female voice, although they handle the larger forms quite credibly. The M12-F165 is suitable for both small tube amp and large solid state amps. The M12-F165 works best in small to moderate sized rooms.

Frequency Response Chart

Low AnglesBlack=On Axis; Red=5o; Blue=10o; Green=15o; Brown=20o

High AnglesBlack=On Axis; Red=15o; Blue=30o; Green=45o; Brown=60o



Total Harmonic Distortion



Cumulative Spectral Decay


The M12-F165 came about because the Fostex FE167E driver was discontinued. I chose the FF165WK as a replacement and I have not been disapointed. The FF165WK is well behaved and very smooth. I reduced the depth of the cabinet to accomadate the new driver. The cabinet is built of 1" Baltic birch is bracing as required. As always, the choice if finish veneer is up to the customeer.

I offer limited custom production here at Hot Springs Village, AR. I will provide plans, flats and completed speakers. Of course, prices may vary at my whim or due to the cost of materials. Since I am doing one-off production, I get no discounts from suppliers. I simply pass on the actual cost of drivers and filter parts. The current price list is:

Plans1 $25
Complete Speakers3 $1695 Contact Me3


The M12-F165 cabinet is 43" high, 10 1/2" wide and 8 1/2" deep. The base is 13" by 11".

Prices are for two cabinets or speakers, delivered to your door. All shipping and handling is included.The standard material is 1" high quality plywood. Non-standard materials or finish are negotiable. If you feel that you will need grills, see Grills.

  1. Plans will be delivered as PDF documents attached to e-mail. Snail mail delivery can be arranged.
  2. Complete speakers are ready to hook up to your amplifier, except that the bases need to be installed. Drivers and all hardware are included. The filter will be installed unless arranged otherwise. The standard finish is quarter-cut red oak veneer, stained to your specification and finished with three coats of tung oil finish oil. For more information about available finishes, see Fit and Finish. Shipping weight is two 70lb packages for two cabinets and one 15lb package for the bases.
  3. Why Contact me? We need to discuss the finish and any other options before we can execute a contract.

The FT-1600 MkII uses proprietary design procedures licensed to me by Martin J. King. Any commercial use of this design, including third-party construction for hire, requires a license agreement from me.

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