[e_biz80]

So I have a pair of the dual 8ohm versions of the subs with the a370 amp.  I can't add a third to this config as it would drop the impedence too low.  Would it be worth the upgrade to buy six of the 16ohm version at $1800 plus $500 shipping ($3600 canadian for me)?  is there that much of a difference from 2 to 3 woofers? Not sure what I would do with the 4 8ohm verions if I did do this.

[Early B.]

So I have a pair of the dual 8ohm versions of the subs with the a370 amp.  I can't add a third to this config as it would drop the impedence too low.  Would it be worth the upgrade to buy six of the 16ohm version at $1800 plus $500 shipping ($3600 canadian for me)?  is there that much of a difference from 2 to 3 woofers? Not sure what I would do with the 4 8ohm verions if I did do this.

Keep it simple -- add a third sub and plop it in the middle of the other two. It's definitely worth it. 

[Captainhemo]

What  sized room  and  how hard  are  you  pushing the duals  now ?

jay

[e_biz80]

my room is 18ft wide and 20 ft deep.  The back of the room is open to a hallway.  Volume on subs are set to about 11 o'clock, but never have heard distortion from them.  My wonder is if adding a third will give more output to feel the subs rather than just hear them.

[Vince in TX]

Are you running primarily stereo audio, or Home Theater?   I am running three subs at the moment (a pair of GR Research Servo Sub 4s in front and an SVS SB-2000 Pro at the back).   For that extra oomph, I have Soundshakers in the seats.   Best decision ever.   I feel every bit of that LFE.   

[Early B.]

my room is 18ft wide and 20 ft deep.  The back of the room is open to a hallway.  Volume on subs are set to about 11 o'clock, but never have heard distortion from them.  My wonder is if adding a third will give more output to feel the subs rather than just hear them.

My room is 13x20 and I have three dual OB servo subs (I'd add a fourth one if I had the space). When I added the third sub, it was a definite improvement in bass slam and I highly recommend it. With a room your size, yeah, you need at least another sub. Try it in the rear of the room close to the seating position if you have space.

BTW -- the back of my room is also open to a hallway. I realized a subtle benefit by putting up a folding door to close off the hallway every time I'm critically listening.

[tom739]

The answer is not an automatic yes or no.
Captainhemo asked the proper question. It depends. I have a pair of 2x12. I don't play music as loud as I used to. Even at my louder levels,  I have to touch the woofers to tell if they are moving. You cannot see them move, meaning I am far from maxing them out. Also, some say a third or forth made an improvement. Some of that improvement may have come from the "subwoofer array technique". Meaning it helps to smooth out bass in room. So not an simple answer.

[mlundy57]

It's been my experience the third driver adds body, weight, and clarity which is due to more surface area and each driver doing less work. The absolute SPL didn't change since the dual drivers weren't being pushed to the max to begin with. It was more an issue of sound quality rather than level. This is what I would expect with going from dual H-Frames to triple H-frames in the front of the room.

I haven't tried a third dual H-Frame in the back of the room like Early B.'s setup so I can't comment on the effects.

[Early B.]

It's been my experience the third driver adds body, weight, and clarity which is due to more surface area and each driver doing less work. The absolute SPL didn't change since the dual drivers weren't being pushed to the max to begin with. It was more an issue of sound quality rather than level. This is what I would expect with going from dual H-Frames to triple H-frames in the front of the room.

I haven't tried a third dual H-Frame in the back of the room like Early B.'s setup so I can't comment on the effects.

Yeah, that's exactly right. I wasn't interested in more SPL. The sound quality improved significantly -- thicker, richer, gut-wrenching bass. I don't know if the third sub smoothed out the bass in the room, but I definitely see how that can happen. Keep in mind that it's not just the bass that gets better -- the entire spectrum improves and the soundstage blossoms.   

Originally, I had my third sub in the back of the room and that's where it sounded best. When we re-arranged the furniture in the den, reluctantly, I had to move the sub to the front of the room.

[e_biz80]

Thanks for the input guys, but I forgot about cabinets. I’d be closer to $5000 Canadian to change from four woofers to six. Don’t think I’m willing to spend that kind of money to find out. One more thought; does Rythmic make and amp that can drive three 8ohm woofers? That might be a cheaper route.

[Captainhemo]

Thanks for the input guys, but I forgot about cabinets. I’d be closer to $5000 Canadian to change from four woofers to six. Don’t think I’m willing to spend that kind of money to find out. One more thought; does Rythmic make and amp that can drive three 8ohm woofers? That might be a cheaper route.

With regards to a  3rd sub,   it doesn't need to be   an ob sub.... typically ,  when Danny used to exhibit at  say  RMAF,  he would run  a sealed, or a pair of sealed servo subs in the rear of the room  with the ob subs up front.   Typically  it  is run out of phase  from the  main subs and at  much lower  volumes and really  fills   in the room.

An  alternative to  going to triples  and having  to deal with your  8 ohm woofers is to go to quads and we happen to   cut those  .     Youi'd only need order  4  more of the  8 ohm  woofers but would also need to  need to either    pick up some of the HX 800's ( I believe they are  currently  out of  stock)  or  another  pair f  A370's.   If you've got the   "right"  ones now,  you    can run them in master/slave mode  so that  one amps controls  adjust  both amps on  one channel.    If not,  you'd need to simply  adjust   both amps  to   the same  settings

jay