[nationalbar]

That is, side by side;  2 adjoined towers per side?  Any cancellation issues?

[Captainhemo]

If you used an HX800 or 2 A370PEQ per side, sure.  You  may be  able to put one tower inside / one outside of each speaker and distribute the bass very evenly throughout the room... we were just discussing this with Danny a couple weeks ago 

jay

[nationalbar]

Thanks Jay

[HAL]

Unless you already have A370PEQ's, the HX800 has more power and less expensive than two of the A370's, if the two 3x12's will be close to each other.  The A370's advantage would be if the two 3x12's need to be separated a large distance for better in room response.  The separate amps phase controls will help each integrate with the main speakers.

Keeping the servo loop a short run of wire is important to each servo amp for best control. 

[Captainhemo]

Unless you already have A370PEQ's, the HX800 has more power and less expensive than two of the A370's, if the two 3x12's will be close to each other.  The A370's advantage would be if the two 3x12's need to be separated a large distance for better in room response.  The separate amps phase controls will help each integrate with the main speakers.

Keeping the servo loop a short run of wire is important to each servo amp for best control.

and, in some cases, the parametric eq may be of  some use.
Also, if the HX800 is like the  HX300,  I believe some of the adjustability ( eg the  extension/damping) is  combined rather than seperate.. I could be mistaken as I have not used  eithe the HX300 nor the  HX800 amp to this point
If it is something you are seriously considering, I'd   look at both and consider the possible benefits to each.
What  rich mentioned abou tthe  cost is a  big  difference

jay

[Danny Richie]

Unless they are wired improperly (out of phase) then there will not be any cancellation.

[mlundy57]

and, in some cases, the parametric eq may be of  some use.
Also, if the HX800 is like the  HX300,  I believe some of the adjustability ( eg the  extension/damping) is  combined rather than seperate.. I could be mistaken as I have not used  eithe the HX300 nor the  HX800 amp to this point
If it is something you are seriously considering, I'd   look at both and consider the possible benefits to each.
What  rich mentioned abou tthe  cost is a  big  difference

jay

I have used the HX300 amps and am not fond of them. They have limited input options, one RCA and one mini XLR (which I have yet to find an adapter that will fit), that's it. Also, as Jay mentioned, the they are a lot less adaptable in that extension, damping and rumble filter have been combined into one switch.  Plus no PEQ (which may not always be needed but when it is it sure is helpful). 

The advantages of the HX300 are smaller dimensions and lower cost. Though when I used them in the speaker stands the lower cost ended up costing me a lot more than the A370s would have. The HX300s are $100 less than the A370s so I saved $200 on the amps. However it turned out the AVR being used did not have preamp outputs. Since the HX300's did not have speaker level inputs the AVR could not feed them. This ended up causing me to have to buy a new AVR with preamp outputs. So save $200 on amps, spend $850 on AVR 

The HX800s have the PEQ and the same extension, damping and rumble filter adjustability as the A370s. The only thing the HX800 lacks in comparison the the A370 is the high (speaker) level inputs. I don't know how much the HX800s cost so I don't know how they stack up compared to the A370s.

As Jay said, look at the features of each vs your needs. If you don't need speaker level inputs and you are going to place both cabinets of a pair close to each other (or on top of each other like Rich has) than you can probably save a significant amount of money with the HX800s. However, if you need speaker level inputs and/or intend to space the cabinets out more than the A370s would work better.

Check everything out up front. Aww shits are funny later on down the road but a royal pain at the time.

Mike

[nationalbar]

Thanks for everyone's help, much obliged!

What I had in mind was building the sub towers as a single unit per channel, i.e.,
like two 12" triples, but attached, (like an Ikea Expedit)..., with six 12" drivers per channel.
I would then use these doubled cabs as speaker stands for my active monitors, the Oceanway HR4's.

Q: Can all the drivers face forward, or should they be staggered Front and Rear, say, in this pattern:

    F  R               F R
    R  F               R F
    F  R               F R

    (L Ch)            (R Ch)

Also, it would seem logical to employ two A370-XLR2 amps per channel, one amp per three drivers, (the 16 ohm drivers)
which would allow me to run the signal balanced from my preamp, to the Master amp,
then jump to the second A370-XLR2 as the "Slave" amp.

[Danny Richie]

You can stagger them like that if you wire them properly.

You can also use one HX800 amp to drive all six of them.

[HAL]

If the two 3x12's are attached, then a single HX800 amp per side which has two Class D amp modules will work with an XLR balanced input and no need to slave the other amp, as it is internal.

Just make sure to understand the wire color code for the HX800 amp.  One amp module has red and black wires, the other has yellow and black wires.

The Red/Black pairs are Red = + and Black = -

The Yellow/Black pairs are Yellow = - and Black = +

[nationalbar]

Thanks, everybody is very helpful here!
But another question has been raised: Why reverse-mount every other driver?
Is there any sound quality difference between staggered vs. having all the drivers face forward?
Or is it just a weight/balance/tipping-over issue?

[corndog71]

Thanks, everybody is very helpful here!
But another question has been raised: Why reverse-mount every other driver?
Is there any sound quality difference between staggered vs. having all the drivers face forward?
Or is it just a weight/balance/tipping-over issue?

A 2-sub cabinet weighs around 85 pounds.  Either way it aint tipping over.

[Captainhemo]

Thanks, everybody is very helpful here!
But another question has been raised: Why reverse-mount every other driver?
Is there any sound quality difference between staggered vs. having all the drivers face forward?
Or is it just a weight/balance/tipping-over issue?

You realize  these triple towers will be 44" tall if you uses 1.5"  base/top and 1" braces... pretty high for stands. At first I thought  you were going to stack them  on their sides (2 high x 3 wide for a 32" high stand) but then I saw your  layout of the drivers. Just wanted to point out how tall they'll be.
You can  reverse every 2nd driver, or you can run them all facing forward (just wire forward facing drivers in phose, rearward facing drivers out of phase), as Corndog mentined, the big difference is  weight distribution.
My triples all face forwards, Yeah, I'd say they are  a bit rear heavy but not overly tippy,  if some drunk dude plowed into them, they'd probably go over but so may a  "normal" set. If you want them all forward and are worried about tipping,  extend the base rearwards an  inch or  two, this will help reduce any problem .

jay

[nationalbar]

Thanks Jay, height is not an issue, the monitors are small horns with 40* vertical dispersion and are currently mounted on Sound Anchor ADMID stands at 44 inches height, angled down and aligned to ear level at the listening position from 18 feet away. But I'm still curious as to whether or not the front-rear driver mounting has any sonic advantage over all forward facing drivers?

[HAL]

The theory is that the opposing drivers cancel some distortion while in operation.

You can also see the opposing driver idea in use with the Linkwitz Labs LX521 speakers bass W-Frames. 

[Captainhemo]

nationalbar,
If you go to page 6 of  my Flat pack thred, post 108 begins  some discussion on this. I know there is no concise  answer to this question yet but I have heard them both ways and I prefer them all facing forward.  I wouldn't say there are huge differences but  I feel there is a bit more definition and more dynamic punch when they  all face forward..... that being said, there was no side by side/A-B comparison done. It was  a change I mde with the  last set of subs I built  for myself after having a couple pairs (1 dual set , 1 triple set) with the opposing drivers
GHoping we'll have some more input onthis soon as I know there are a couple others  who'll soon  be trying this setup

jay

[nationalbar]

Thanks, everyone!