FR preferences

[Salas]

Hello all,

How would you prefer two 3.3'' fullrange gems in a closed box not bigger than an LS3/5a arranged? Touching together as a vertical double I suppose.
But would you run them in parallel with just BS correction...or 1.5 way trading 2dB for single source above 1kHz?
Hmm any expert opinions?

[Salas]

There was a fairly long thread in 2003 where 7V was using 4 in a vertical tight array. Danny pointed to 1.5 way. You were about to meet and have a listen you guys. What happened? any conclusions?

[Timn8ter]

I've built one or two such things and prefer to mount the drivers back to back, bipole fashion, couple the magnet backs with a wooden dowel then wire the drivers in series.

Example:
http://www.timn8er.com/bipole_fostex_fe103e.htm

[Salas]

A friend uses them like that but reverse parallel wired for dipole and spl gain, he likes it a lot. Do you do anything more for bsc?

[Timn8ter]

No, having the rear facing driver in phase takes care of BSC. Wiring in phase and coupling the drivers also reduces adverse mechanical effects on the cabinet. Wiring in series provides an easier load for the amp and from what I've read helps the damping factor.
http://www.6moons.com/audioreviews/f...firstwatt.html

[Salas]

Thanks for your input, I will mount 2 Visaton FRS8s (8 OHM version) on a 26X16X16 cm plywood cabinet front and back and experiment bipole, dipole, series & parallel. I will listen with 20W classA triode, measure accurately with calibrated mic, and I will post back my findings in this thread when I will reach to some conclusions.

[Salas]

Hello,

I built a pair of 26x16x16 cm boxes out of 15mm plywood and arranged 2 Visaton FRS8 parallel connected bipole (push push front and back). The driver centres are 10 cm down from top.
The sensitivity is 85 dB SPL for 2.83V @ 1m. They must sit on stands with their front baffles 60cm from back wall for best balance. I had to use a notch to cure an octave band forwardness from 1.5 to 2 kHz. I built, measured, and listened carefully to about 12 notch filter combinations. When I finalised the notch I got excellent results. The best thrill I ever got from listening to a small quality speaker (wait for 48hours for treble to open up, if the drivers are virgin). The Visatons are 15 Euro each so you can understand what I will recommend over a BBC for a small nearfield... Funny is that the result is far more exciting than a BBC too.
The Visatons go well for bass down to 80Hz arranged as such. I am posotive that the sound without notch is far inferior to the notched speaker. I am looking to experiment with TB W3-871s and I would like to know if anybody has experience from FRS8 and TB to tell me how do they compare. I am thinking of ordering a TB quad. Added sensitivity would be much better but I have seen diyers measurements of 82dB instead 87 TB says...

[Salas]

the cap is consited out of 2x15uF + 1x 5.6uF

[Salas]

...

[Salas]

Nobody ever had used Visaton FRS8 and TB W3-871s ? any comments on how they compare?