Stacking 703s on 750s?

[beden1]

I am thinking of adding another subwoofer to my system that is in a large room 32' X 18' with 24' ceilings (excellent acoustics). I run a Pioneer Elite 82 receiver (130 watts X 7 channels), a pair of 703s (bi-amped fronts), an HTM7 center, and an ASW750 subwoofer.

The wall where I have my stereo has limited space between a door opening, and I would like to add a second ASW750 subwoofer.

Is there any downside to stacking a 703 on top of each 750 subwoofer?

Thanks for your help.

[beden1]

I received a response from B&W. They said it would not be advised as it would place the tweeter and mid range above the listener's ear level.

Back to the drawing board to realign my space.

[KRC]

Also there is the safety issue of 60 pounds of speaker perched about 20 inches off the floor. I do not know if you have kids or entertain alot where this could be a real issue. I know I would not want to start drilling holes into the top of the sub either.

Kevin

[chinets]

OUCH !!! speakers stacked over subs...A big NO NO !!!
Put your subs against the side walls, or one in the front and the other in the back, but on top of each other is asking for some serious problems.
You would be living in the danger zone if you did that!!!
With the size of your room ,you should NOT be restricted to doing that type of drastic move, and you will damage your speakers and Sub if you play the music at loud volumes or are watching HT with large booms. You are asking for serious problems if you went down that road. Not mentioning ,that they could fall when the sub starts to kick in ,and Earthquake tumbling will happen!! TIMBER !!!!!
Keep your kids and pets out of that room, as you have a safety hazzard buddy!!
I would suggest wearing a safety helmet every time you audition a CD or DVD In that room !! Preventive measures for your safety buddy.
Good Luck you dare devil,
Cheers!!

[BassThatHz]

I really don't think the 750 was designed for a 13000+cu ft room.

Your only hope of filling a room like that is either a pair of: B&W 855's or Velodyne DD-18 or perhaps DD-1812's. ;x(

It would take approx 7 ASW750's to match that level of displacement in which your room requires. :twisted:

[chinets]

I'm with BassTatHz,
You have enough room to put your Subs anywhere really !!
You could have a school of subs in that room size M8 !!
Don't hurt yourself with those speakers stacked on top of those subs!!
I guess you are into NO PAIN NO GAIN!!
Cheers

[beden1]

I really don't think the 750 was designed for a 13000+cu ft room.

Your only hope of filling a room like that is either a pair of: B&W 855's or Velodyne DD-18 or perhaps DD-1812's. ;x(

It would take approx 7 ASW750's to match that level of displacement in which your room requires. :twisted:

It's interesting that you say this, as I recently found that adding that much sub power/presence defeated a quality/natural sounding system.

I recently visited my friend who just purchased a very high end system including Anthem pre-amp, Anthem amps, JMLabs Alto Untopia fronts ($25,000 each), (4) JMLabs subs (their 18s), along with a JMLab center (? their top of the line). He has a room similar in size to mine, with more furniture and lower ceiling (14') to my 24' ceiling.

He just had it professionally calibrated (I feel it still needs tweaking).

What I found, was that the subs were drowning out the highs and mid range of very strong fronts, and the sound was not natural at all. For movies, it was exciting but was still definitely on the heavy base side. For music, it was very hard to listen to, because as I said, the base was drowning out all else. (in fact, his subs have already cracked 2 pillars he has in the room and the corner of one of his walls in just 2 weeks)

I started playing with it to try and create a better balance, but in the end, our combined opinion was that he really did not need the 4 subs, or should have gone with smaller ones for his room (I agree with your suggestion of Velodyne DD series subs, as I have two DD-12s in the system in my other house).

My large room is very bright and with much less power/force needed, and produces a dynamic, transparent and balanced sound, particularly noticeable while listening to recorded live performances. I feel that the 750 sub that I have will be better balanced by adding another one next to the left front (the other is currently next to the right front). The 750 really blends well with my 703 fronts that have strong highs and mid range.

To each his/her own, but I think that some listeners are getting too addicted to the strong force of base, as opposed to creating what music/sound truly sounds like in live performances.

[dknightd]

I'm actually tempted to try the same setup. I have 703 and most of the time they have enough bass, but sometimes not. In my room the 703 sound best when I sit with my ears just a little below the tweeters. Fine if I'm sitting, but sometimes I like to get up and dance. Then my speakers sound a little too bright, and loose the bass thump.
Even without including a sub I've thought about experimenting with the height
of the speakers. I don't know yet how my room and speakers will respond to
move the 703 up a little bit. If the 703 sound good elevated by 1' then perhaps I could
slip a sub under them. Then the issue would be does the vibration of the
sub hurt the sound of the speakers sitting on top of them. Maybe a simple
stand to elevate the 703 without touching the sub below would work.
I have my 703 and room treated to give me the best sound in my seat,
probably I'd have to change things a bit if I moved things vertically, but maybe not.
I don't think you can decide if putting a 703 on top of a 750 is a bad
idea untill you try it in your room. It could be that elevating the 703 a bit (6" or so)
and putting subs behind them would be a better solution. Right now I'm in the
thinking stage. If I had the subs I'd be experimenting.

One concern would be the sub vibrating the speaker sitting on it. I don't know if this a real problem or not since I haven't tried it. I'd like to.

[beden1]

I asked B&W about the vibrating issue, if I put the 703s on top of a 750 subs. They said it should not be an issue as long as I had their rubber feet installed (included with the speakers). But, they had not experimented with this type of set-up and could not be certain that the rubber feet may, or may not start to marr the finish on the 750 sub after a period of time.

I experimented with a set-up in my other house where furniture was starting to hurt the transparency of my sound. I went to Home Depot and bought two door stops, the ones that are triangular in shape. The ones they have come in a variety of woods and materials, along with rubber pads on top and bottom. I bought the light cherry ones.

I put these under my two large ADS 910 Reference front speakers, which elevates the speaker fronts about 1 1/2". This made a noticeable difference and solved my issue very well. You may want to try this, as it will position your speakers ideally for when you are upright, as well as making the sound more transparent when you are sitting/lounging. I have had these speakers for 30+ years and they originally came with large stands that enabled you to angle the speakers. (Unfortunately, the stands got lost in one of our house moves).

I also tried these door stops under one of my sub-woofers to see if it tightened the bass reflex. It worked well, but, the vibration I felt on the sub was greatly increased, and I figured it was best to try something else down the road.