Enigma Subwoofer 1980s

The Controlled that came with the woofer array had three stages of equalization. Stage one was a 6dB/octave low pass network that compensated for the normal roll off due to open back dipole cancellation. That equalization needs to be correct from 25Hz to 1kHz. The next stage was an 18db/octave high pass filter at 25Hz. As an option, this could be higher order than 18db/octave but NOT less than 18db/octave. The last stage is the crossover from the subwoofer to whatever full range speakers you are using. The crossover in the Controller had matching high and low pass filters at 100Hz and were also 18db/octave. All filters were maximally flat (Butterworth) types.

These things came with detailed setup instructions -produced really nice tight musical bass.Have heard them mated up with things like stacked Quads and the combo worked! Not sure if they would be particularly appropriate or effective for dinosaur footfalls - but will blend into a music system just fine.
You really do need the controller/X-over for these speakers since they are mono and dipole radiators - the controller is a necessity.

Thank you very much for the reply. I will look into getting the cross-over which I do not have.

Your comments were greatly appreciated.

Regards,
Gary

I have the entire system – (array,amp and controller) utterly fantastic -- no booming just pure unmitigated pure base -- the woofer with its 4x15 inch drivers should be positioned about 18 inches in front of the full range speakers -- on choral pieces it is absolutely stunning. The power and controller sections are in for check up now as is the array being inspected for integrity of the cones. This was a find – purchased in the late 80”s used. Few were produced and rumor is that they were in the $8k range back in the late 70's early 80's – it is large standing on pylons floor to top 46 inches high – array is 34x34 x8inches –power amp and controller separate units well over 45lbs. Would like to find schematics for my techs. The combination of this unit with valve pre and amp plus the floor standing ProAch’s and Von Schweikert S1 produces an amazing sound environment. I will repost any technical information assembled after the tune up on this site for anyone fortunate enough to have discovered one of these monsters!
THS 10/11/13 -- csynergy10@aol.com

There is almost no information on this device out there. I did find out that it retailed for 2295.00 back in the 80s which means it was a high end piece. It could also get down to 20hz. I also wish I had a schematic also. I have removed the cloth from mine as I thought the speakers had an issue. As it turns out the speakers are in great shape still with good foam surrounds. My controller functions intermittently so I don't use it now. I agree with you. When it was working it could definitely put out the bass. Dipole subwoofer sounds different than a box subwoofer.

Have your tech put a signal generator to the electronic equalizer. It would be very valuable if your tech can find out the following:
1. what frequency does the 18db/octave low pass kick in.
2. what frequency does the 18db/octave (or 6db/octave) high pass kick in.
3. resonant frequency of the woofer
4. most critical is to understand at what frequency the 6db boost occurs to compensate for the open baffle dipole fall off.

The woofers are custom designs with an xmax of 1". The Enigma was ahead of its time!

Let me know if you find this info as I would like to restore my enigma.

Congrats on a great find.

gwho