I have a pair of Rocket UFW-10 subs, and will soon be buying a pair of stand-mount monitors. I want to save space by mounting the monitors over the subs. I have two options. One is to place 12" (30 cm) stands between the subs and the monitors. The other option is to sit the subs on stands, and place the monitors directly on top of the sub cabinets. I think option #2 would give me better stability, but I'm wondering if having the subs 12" above the floor (woofer centers at 20") will improve the sonics, or cause a problem due to floor bounce?
Any ideas for stand construction or materials? A welded and painted steel frame is the obvious solution. What about coupling vs. decoupling?
Any ideas for stand construction or materials? A welded and painted steel frame is the obvious solution. What about coupling vs. decoupling?
A sub on the floor with a stand in between is what I would do. Perhaps make a base on the stand the same dims as the sub footprint, and with a similar finish, or just black, then a stand. You could easily do this with MDF. Make two rectangles, on the base to go on top of the sub, the other the base for the monitor. In between you could make a rectangle to attach the two.
If you really want it stable, then you could have a vertical plate to which everything is screwed together at the back - sub, monitor and stand in between.
If you really want it stable, then you could have a vertical plate to which everything is screwed together at the back - sub, monitor and stand in between.
paulspencer said:
What's your reasoning for that choice Paul? What's the advantage with leaving the sub on the floor?
Stability, which comes from keeping the heaviest part down low sitting on the ground. Also from a looks point of view.
paulspencer said:
Thanks Paul.
The monitors are 44 lbs each, the subs are 52 Lbs each. Maybe I should build stands weighing 60 lbs and put them on the bottom. 😉
You could screw fix the stand to the underside of your monitors and make the plinth base of the stand the same footprint as the subwoofer, sitting on top of the sub. If that is not solid enough for you, then there isn't much you can do short of fixing them all together as if one speaker then bolting it all to the floor!
Ideally you want to isolate it from the floor, so that you avoid transferring vibration from the speakers to the floor which would then become an unintended transducer adding coloration.
Ideally you want to isolate it from the floor, so that you avoid transferring vibration from the speakers to the floor which would then become an unintended transducer adding coloration.
paulspencer said:
My floor is pretty good. It's poured concrete with 2" joists and oak hardwood on top. The subs are on 3 rubber feet now.
I should have mentioned that the subs are 13" cubes, so mounting them on top of some sort of stand wouldn't look too ungainly. I've heard some people claim that getting the sub up off the ground can improve the sound, so I was wondering if there was a down side.
A sub with the driver close to the floor is going to work better with the room than higher up as the effect of closer boundary dimensions are outside or at the limit of the sub range, such as 180mm gives a maximum boost at 83Hz but 400mm would give a maximum boost at 41Hz . There is some software around for this somewhere but can't remember where I saw it.
Plus you've got all this energy in the driver that can vibrate a stand severely.... cripes, I've seen subs walk across the room (well starting to make a run for it). I think what they mean by getting the sub off the ground is lift it by about 40mm on spikes or feet and you need something that can also grip onto the floor. Got sick of mine trying to relocate itself.
Plus you've got all this energy in the driver that can vibrate a stand severely.... cripes, I've seen subs walk across the room (well starting to make a run for it). I think what they mean by getting the sub off the ground is lift it by about 40mm on spikes or feet and you need something that can also grip onto the floor. Got sick of mine trying to relocate itself.
SWMBO says the subs should go on the bottom. So do you guys, so that's what it will be.
Paul's mdf idea is intriguing. I'll go that way and see how it sounds. Maybe add some sand. Sure won't cost much 🙂
Paul's mdf idea is intriguing. I'll go that way and see how it sounds. Maybe add some sand. Sure won't cost much 🙂
I've tried programs to simulate room gain and room modes, but in comparison to measurements, there is very little correlation - they are useless.
There will always be someone to say that doing something makes it sound better! The difference in sound with moving the sub off the floor is likely to be more measurable than audible. It will affect room gain and room modes by a trivial amount. You won't suddenly lose gain by raising it up, but instead lose a tiny amount.
I just think a sub looks better sitting on the floor, not up on a stand.
There will always be someone to say that doing something makes it sound better! The difference in sound with moving the sub off the floor is likely to be more measurable than audible. It will affect room gain and room modes by a trivial amount. You won't suddenly lose gain by raising it up, but instead lose a tiny amount.
I just think a sub looks better sitting on the floor, not up on a stand.
Paul
My previous comment was about having it very close to a boundry so no or little gain is realised in the sub's range for 1 boundry. I believe you get smoother performance if all 3 boundry dimensions are different and at least one is outside the sub's range and maybe one of the reasons downfiring work well.... dunno.
Using +3dB gain at 1 boundry dimension (that is 0.05 x wavelength), then when we have driver 100mm from the boundry, the 3dB gain is at 166Hz which is outside the sub's range so doesn't effect the response. There are of course gains and losses at other frequencies but have picked a maximum point.
I had a problem with my sub location due to having to be stuffed into a corner.... 3 boundries which is not good for a smooth response IMO. So I made the sub side firing and about 80mm from a side wall. The other 2 dimensions are different so all in all worked out well.... but saying that, 2 equal boundry dimensions can be helpful to boost the same frequency. It's the third boundry that's the problem IMO.
The numbers above are from a Aus Hi Fi article in the 70's and more to do with stereo speaker placement but the fundamentals still apply and was based on L.L. Beranek, Acoustics, 1954, a book which means nothing to me.
Cheers
My previous comment was about having it very close to a boundry so no or little gain is realised in the sub's range for 1 boundry. I believe you get smoother performance if all 3 boundry dimensions are different and at least one is outside the sub's range and maybe one of the reasons downfiring work well.... dunno.
Using +3dB gain at 1 boundry dimension (that is 0.05 x wavelength), then when we have driver 100mm from the boundry, the 3dB gain is at 166Hz which is outside the sub's range so doesn't effect the response. There are of course gains and losses at other frequencies but have picked a maximum point.
I had a problem with my sub location due to having to be stuffed into a corner.... 3 boundries which is not good for a smooth response IMO. So I made the sub side firing and about 80mm from a side wall. The other 2 dimensions are different so all in all worked out well.... but saying that, 2 equal boundry dimensions can be helpful to boost the same frequency. It's the third boundry that's the problem IMO.
The numbers above are from a Aus Hi Fi article in the 70's and more to do with stereo speaker placement but the fundamentals still apply and was based on L.L. Beranek, Acoustics, 1954, a book which means nothing to me.
Cheers
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