[Early B.]

After consulting with Danny, I will proceed with a single dual 12"-woofer subwoofer in an H cabinet, placed horizontally on the floor between the main speakers

Once you build it, try it both ways -- laying down and standing up. The sub will sound a bit different placed horizontally on the floor. You may prefer it standing up which is how it was designed. 

[Captainhemo]

After consulting with Danny, I will proceed with a single dual 12"-woofer subwoofer in an H cabinet, placed horizontally on the floor between the main speakers (Falcon LS3/5a), which are positioned on stands in nearfield, and far away from the back wall. I have two questions:

a) should both woofers be front-facing or one front and one back?
b) does it make any difference if the woofers are 8-Ohm or 16-Ohm?

Thanks

As I noted,   no, it  is not going to make a difference   other than appearence  how you  orientate the drivers... you  just have to wire them accrodingly.
And again,   no,   the 8 and 16 ohm versions will souind the same althouigh, if using the A370 PEQ  amps, h in some  HT   applications, you  may be able to drive the  2  8ohm drivers  to x-max.    The  8 ohm drivers also   take away the option  of upgrading  your dual cabinets to triples.

jay

[Chops]

a) should both woofers be front-facing or one front and one back?
b) does it make any difference if the woofers are 8-Ohm or 16-Ohm?

Thanks

A) Facing them in different directions (one front firing, one rear firing) will help reduce/eliminate even distortions from the driver motors and suspension systems, making for an even cleaner sound. That's the way I would go.

B) I would go with the 8 ohm drivers, so once wired in parallel they present a 4 ohm load to the A370PEQ amp, resulting in full power potential (370 watts). Although, on Danny's site for the Servo Sub Kit 4, it states using the 16 ohm drivers. Not sure why. That would be cutting the amp's output by half, providing you with only 185 watts on tap.

[Chops]

And again,   no,   the 8 and 16 ohm versions will souind the same althouigh, if using the A370 PEQ  amps, h in some  HT   applications, you  may be able to drive the  2  8ohm drivers  to x-max.    The  8 ohm drivers also   take away the option  of upgrading  your dual cabinets to triples.

jay

I see your point, but I would be more concerned possibly damaging the drivers from the amp clipping vs bottoming out the drivers from more power. Neither is good, but I think clipping is probably a bit worse, both for the drivers and the amp.

I know when I had my ugly huge 15" OB subs (dual H-frames) many moons ago (four 15" Pyle Pro drivers) and a couple of different amps tried out on them, the amps never pushed out more than about 20 watts peak, and that was LOUD, as in chase you out of the room loud. Then again, that was a lot more cone area, a lot more baffle, and a lot more efficient at around 94 dB @ 1 watt per channel.

It was also the absolute best sounding bass I have ever heard anywhere, at any price, and I have heard tons and tons of subwoofers, extremely expensive ones I might add. None of them compared to my ugly home brew mess, even to this day.

[Captainhemo]

You'll never    clip the amp withthe   2 16's, I've never had to   use   anywhere near full power.
I have  2 16 ohm in my Super 7's  (95-96db) as did all the original Super 7's from Serenity Acoustics,   and     again,    subs have no issue at all  keeping up  even at   less than  the  12 o'clock position  on the  amps volume setting,  still tons of headroom.  Even the  Super V's (97/98db) used the  2  SW12 16FR's  with no issues

As for  the   all forward, ore  opposing woofers, again, the difference is  inaudiable.  There have actually been cases where people report they feel  they sound better  with   all  forward facing woofers... in fact,  the first time  we did it here, we felt the same.  After   going back and forth a few times,   I can't  actually tell....  . 

I run both the woofers in my Super 7's facing forward and I believe Danny is still running  a set of triples    with all  3  woofers facing forward   that  we sent down to him

jay

[pankon]

...It was also the absolute best sounding bass I have ever heard anywhere, at any price, and I have heard tons and tons of subwoofers, extremely expensive ones I might add. None of them compared to my ugly home brew mess, even to this day.

Thanks for the feedback. I also hope that the GR-Research OB sub (kit 4) is going to augment the performance of my LS3/5a speakers, which are missing the bottom end (below 70Hz).