Brines Acoustics


FT-1600 MKII

FT-1600 MkIII

Fostex FF165WK Mass-Loaded TL

Last Modified 6/30/10

The FT-1600 MkIII 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 FT-1600 MkIII is suitable for both small tube amp and large solid state amps. The FT-1600 MkIII works best in small to moderate sized rooms.

Frequency Response

Note: This is a farfield frequency graph, and the data below 500Hz is contaminated by room interactions, particularly floor bounce at 175Hz. However, it gives you a good indication of what to expect in your rooom.

The original FT-1600 just happened. I really had no plans for a full-range project, but then a fellow asked me about licensing a design for serial production, so I decided I had better at least test the design. I ordered parts, and in a week, they were playing beside the "Peerless Pipes". Then, a friend called and said that her speakers were sounding scratchy. Yea, I'll bet! The foam surrounds were completely gone. So, I demo'd these speakers, which I just happened to have in my car. They were in raw MDF, the tops were not trimmed, and they were sitting on loose boards for bases. She complained that the speakers were too tall, wouldn't fit her decor. But, she agreed to hear them since they were there. On went Diana Krall, then Alison Kraus, Sade, E. Power Biggs plays Bach. After 15 minutes of listening in silence, my friend looked up and said "How Much". So I sold them on the spot, then had to take the speakers home and finish them, knowing that I'd not get to enjoy them.

The FT-1600 was designed from the outset for acoustic music. These speakers excel at jazz, solo voice and classical. The full-range Fostex driver has a rated sensitivity of 94dB/w/m, making the FT-1600 MkII a logical choice for low-power tube amplifiers. However, the FT-1600 MkII works equally well with solid state amplifiers. The advantages of a high efficiency speaker must be heard to be believed. Usable frequency range is 35-24,000Hz.

The MkII version was an evolutionary improvement upon the original design. Over the three years since I published the original FT-1600, I have tried to improve the mid-range presence by reducing the amount of stuffing in the cabinet and at the same time, reduce the amount of ripple in the upper bass/low mid-range area. This was accomplished by reducing the cabinet height by 3 1/2" and adjusting the driver and port positions. It was necessary to abandon the slot port at the bottom of the baffle in favor of a round port 4 1/2" up from the bottom. The re-sizing and rearrangement of the cabinet was so successful that there is now no stuffing in the cabinet whatsoever. The only damping inside the cabinet is 1/2" of yellow acoustic fiberglass applied to all sides and the top.

The MkIII 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
Flats2 $395
Complete Speakers3 $1595 Contact me


The FT-1600 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. Flats include all panels and braces ready for glue-up. The plinth and false baffle are drilled for mounting screws. Drivers, filters and all hardware will be provided by the customer. Shipping weight is 50lb each for two packages.
  3. 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.

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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