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weight on subwoofers

Wiley
02-11-2006, 12:15 PM
Ok, Audiophiles here's my question: Would placing a fixed weight on top of my subwoofer cabinet (freestanding box type unit) improve the sound? Somewhere in the dark recesses of my memory I recall reading that it does. Easy to check but, like the medical profession "First do no harm", it's easier to ask than to replace the sub (and cheaper too!) Anybody done this?
Thanks in advance.
Wiley

JohninTenn
02-11-2006, 01:01 PM
a bigger speaker ie: magnet..Not a brick..:

hdtvpros.com
02-11-2006, 04:30 PM
Yes it will improve. As long as the weight on top of your old subwoofer is a more powerfull new subwoofer. lol

holtzd
02-11-2006, 08:08 PM
The weight may keep the speaker cabinet from moving so the cone of the woofer moves the air instead of the cabinet. Also it may tend to transmit more of the bass to the floor and move the floor more. This would give you more perceived bass because you may "feel" more bass. I remember a long time ago Polk Audio had a pair of speakers that came with what they called a "Bass Brace". It was a bracket that mounted to the back of the speaker and to the wall. This was to keep the speaker cabinet from moving when the cone was moving in and out. Again to move the air instead of the cabinet. So there may be something to this theory. Maybe Ill go get that old set of barbells from the basement and stack the weights on my subwoofer. Sounds like too much work though.

daleb
02-11-2006, 08:22 PM
This was mentioned as a 'tuning' goodie on some audiophile sites. The theory being adding some rigidity to the cabinet structure, or resonance dampening. Unless you have a cheap sub with poor construction, such as inadequate cabinet bracing, etc, who knows... it might work.

This would be much more useful, as a lightweight improvement, espcially if you live in an apartment, condo, etc. and tend to play your system loud.

http://www.truesoundcontrol.com/products/GRAMMA.html

The isolation aspect is a good one I think, how much it 'sounds better' is up to your ears.

maicaw
02-11-2006, 08:32 PM
Ok, Audiophiles here's my question: Would placing a fixed weight on top of my subwoofer cabinet (freestanding box type unit) improve the sound? the Sunfire Subwoofers as far as I know come without spikes for "decoupling" and the instruction manual for them says that they should be free to bounce around in their location-as I recall -. The website sunfire.com seems to be down at this time so I can't download the manual now - but theirs are two cones moving in opposite directions and those instructions may not be applicable to single cone woofers. Are you using the spikes if any came with the speaker.- they are supposed to give the best performance by letting the cabinet "float" above the floor.-edit -I found the brochure on my computer - here's what sunfire says
Do not place heavy objects on top of the unit.
Do not place the subwoofer with its control panel against the floor.
If you wish to place your subwoofer so the drivers face the floor and ceiling, thereby moving up and down, use at least 1-1/2 inch high spikes or feet for support. They may be attached either with screws or self-stick backing. This ar range - ment will impart substantial house and floor shaking motion.
Four extra heavy, shock absorbing rubber mounting feet have been included. If your subwoofer tends to wander about slightly while in use, place these feet just inside the existing feet positions. These shock absorbing mounts will let the subwoofer rock freely, thereby absorbing low frequency rocking energy, allowing it to adhere solidly to the floor.

Wiley
02-12-2006, 01:16 PM
The floor of my theatre room is a slab on grade w/ two coats of vapor barrier paint and then the Samsung hlp5685 and equipment stand are raised on a dias consisting of a 3/4" sheet of treated ground contact plywood and then another sheet of 3/4 MDF on top of that is carpet. The rest of the floor area is covered with interlocking tread surfaced foam material. There is 5x8 carpet in front of the first level couch.

The sub is a down firing single cone unit. There isn't much if any movement of the cabinet when it is working. In opening scenes of "Serenity" for example, there are a series of single "whumps" that expell a fair amount of air thru the port. It was to an extent distracting; enough that a visitor commented that the theatre has wind effects. I moved the subs off the concrete and onto the raised dias mentioned. Now the sound seems slightly muted and that's when I remembered reading something about weighting the sub. I have also come across info advising to place the sub on a heavy hard surface such as a block of concrete.

Lots of info online, and as we all know, alot is quackery. I was under the impression that the port should face the listening area. Is that true? If not then I could return the sub to the concrete floor and simply face the port away from the seating.

It's not a problem of not a powerful enough sub. I only have the volume setting at a 5 on the scale of 0-10.
Thoughts?
Thanks
Wiley

maicaw
02-12-2006, 01:36 PM
Lots of info online, and as we all know, alot is quackery. I was under the impression that the port should face the listening area. Is that true? If not then I could return the sub to the concrete floor and simply face the port away from the seating... Thoughts?Thanks Wileythe sunfires which are dual cone 12" 2700 watt :D >$1500 uints recommend putting the units in a corner with the cone(s) directed at 45 to the walls per attached page -I think their instructions are reliable -

daleb
02-12-2006, 02:53 PM
I think would be difficult to generalize the proper orientation of one sub (brand) to another. Although, the various corner locations are probably the one thing that would effect most subs the same way.

I am not sure the Gamma stand would be a good solution for a down-firing sub. Again, it's primary purpose is isolation. And I believe any improvement heard by some is related more to characteristics other than just boost.

You say your impression is less bass, but does the bass sound thin? Or maybe it sounds less boomy, or smoother?

I think it would take a several recordings, not necessarily just test CDs, as well as DVDs, to adequately judge it.

My M&K is front firing, and I noticed a slight drop in bass (easily compensated for) but I think it actually sounds better.
It does sound different, but again the changes are subtle.

Being an experimenter by nature, I would put the down-firing sub on a large stepping stone and done some serious listening. It could be what you need, or the stand could just be what you don't need. :)

Wiley
02-12-2006, 04:15 PM
and I think the wattage might be excessive for my little 11x19'6"x8'4' room. And if I spent that kind of money on a sub, well my darling wife who has gone along with this little tangent of mine, might be a bit less enthusiastic.

Looks like experimenting is the way to go. Seems from what's been said I shouldn't damage anything by restricting the subwoofer cabinet. And that was my big concern.

Daleb, the sound is simply muted, that's the best way I can describe it, softer with less of an edge. Not bad, but I guess it's a matter of what I had gotten used to, just different. I got to see a HDILA set next to a DLP next to a LCD at Costco the other day. It is all a matter of what is pleasing to the viewer (listener). I still perfer what I purchased, and I'm glad of that. So I'll take your advice and play alot of different DVDs and see if the new position produces a sound that will become what I prefer, and experiment.

Thanks,
Wiley

daleb
02-12-2006, 05:33 PM
There are so many factors, including personal preferences, about the best we can do is exchange experiences and often there is some new information that gets us to another step.
I enjoy playing around with audio. It is much more forgiving, and the changes you can make can be quite dramatic at times. Assuming you are starting off with decent speakers.
With video, once you have a display you like, you are a slave to media, be it software, or broadcasting. Except for controlling ambient light, there is little you can do in your viewing area to make a substantial change without it costing money. Often, a lot more money.