[SteveKi]

The Monolith of Subs!

Hal,
Did you ever finish building the Monolith. If so can we get a review of how it sounds.
TIA,
Steve

[HAL]

I only have 1/3 of each tower built. 

Once I have more money will be buying more OB servo drivers and amps from Danny to complete them. 

[SoCalWJS]

Second pair of servo subs installed in the modules.  Wired up the left channel drivers and will work on the right channel tomorrow.

Did you ever try the Neo 3/Neo 10 with the 2x12's?

I have the Super V's up and running at the new house and considering they're kind of shoe-horned in and almost in a little alcove, hooked up to a tiny Denon AVR, they sound OK.

There's a part of me that wants to try to take them in the direction of the Serenity Super 7's though......

[HAL]

I tried the 2x12's with the HX300.  The PEQ370's sounded better with those drivers, so going to those amps.  Have to make sure the wiring is the same for both as the next step.  Just taking them off my Super-V's.

The NEO3/NEO10 combo with the dspMusik as the digital crossover sounds very good (used with the 3x8" servo U-Frame).  No where near as much output as the Super-V's coaxial, but it is more of my style, since I like planars.  Problem is getting any more of the BG drivers since they were sold to Christy Digital last year.  No new production drivers have been available since last December.

Have to get the rest of the unused 1x12 modules out of the room to set it up and listen.  Now to make some storage space.

[nrenter]

Do the servo driver "sets" need to be in close physical proximity? An entire tower of woofers seems a bit overkill, but placing a driver close to the floor, and another driver about 1/3 of the room height would help better load the room in 3 dimensions. Just a thought.

[HAL]

You need to keep the servo wiring short for best operation.

Was not overkill in the late '70s when Infinity built the IRS Reference III speakers with two 6x12" servo subs.

[bdp24]

Do the servo driver "sets" need to be in close physical proximity? An entire tower of woofers seems a bit overkill, but placing a driver close to the floor, and another driver about 1/3 of the room height would help better load the room in 3 dimensions. Just a thought.

Using the OB woofers separately (rather than in pairs or trios) is not an ideal implementation of them for a couple of reasons. First, as HAL just said, the wiring between the plate amp and woofer(s) has to be as short as possible. But also because the OB woofers do not have as much output as the non-OB woofers, and require being used in at least pairs to increase their output. A better sub to go with for your idea of subs at different locations in a room would be standard non-OB 12" GR woofers in sealed boxes, each having it's own plate amp. If your sub locations require long inter-connects from pre-amp to subs, consider getting the XLR version of the A370 amp, for balanced connections.

HAL, I couldn't swing the price of the IRS' (few could!), but did have a pair of Infinity's Reference Standard Ib, the mini-version of the IRS. It was comprised of an open baffle "wing" onto which were mounted EMIN and EMIT midrange and tweeter ribbons, with a separate sealed column housing six 8" servo-feedback woofers.  I prefer my current speakers, Eminent Technology LFT-8b's with GR Research OB subs (each having two 12's)!

[nrenter]

So, define "short" and "as short as possible"? Are you saying that putting a 3' gap between each of the drivers of the 2x12" servo sub configuration would be too much distance? Or, with the "monolith" structure, putting drivers in the bottom (position 1) and another driver in Position 4 (starting the count from the bottom) would be too great of a distance?

Or, maybe a more interesting question...if you could only add drivers one at a time to the "monolith" frame, what is the position sequence?

[bdp24]

Danny's original OB/Dipole sub design was a pair of 12" woofers in a W-Frame, the plans for which can be found on the GR Research site, in the specs for the woofer itself. He then designed an H-frame, which also uses two 12's in a single assembly, the plans for which are also in the 12" woofer listing. The single-woofer H-frame (six of them stacked atop one another) you have been looking at pictured here was designed only to make the subs more manageable, size and weight-wise. It wasn't done to make each woofer separate---the stack of six single-woofer H-frames could just as easily have been made as three dual-woofer H-frames, but each would have then been twice as big and heavy.