Subwoofer vibration problem

[whmacs]

Hi All,
When I installed the home theatre in the family room my wife was pretty flexible except for two things. 1) No wires visible 2) no speakers or subwoofer on the floor. To met this requirements I used Jamo THX D6 speakers that are wall mounted and the Jamo 15" SW-3015 servo subwoofer that sits in the cabinet on the right hand side. This cabinet is 3.8m x.8m x .8m and quite solid (see attached link). The problem I have is that the sub will sometimes cause the cabinet to vibrate when a long low notes are played in the 28-38hz range. I realise that the best solution is to move the sub out of the cabinet, but this would violate rule (2) and is not an option. Is there anything I could sit the sub on in the cabinet or insulate the enclosure that would minimise these vibrations?
Cabinet (sub on right)

Thanks,
Stephen

[Snap]

Hey Stephen,
My guess is that the its the doors that might be making most of the noise! Wait a minute..... First..... Sweet sysem man. It looks very nice.

I would try this. Glue some carpet or some thing that is soft to the inside of the doors. That will take away the wood on wood rattle. (If that is what it is). Then if the Sub is directly on the bottom wood of the cabinate, try placing a cut of carpet under the sub so that the sub is sitting on the carpet and not wood on wood again.

Not sure if that will help, but it is something that you might want to try.

snap

[gd]

The eternal battle... wimmin vs speakers.

Your screen / cabinet setup is absolutely handsome -- and that sub is never gonna work properly while tucked away in a cabinet... box subs are designed to interact with the entire room, and the cabinet treatment will necessarily inhibit that.

The only solution I can think of is a costly one -- an in-wall sub... by now there should be others, but the only specialty manufacturer I can think of is James Loudspeakers... never heard them, but they are well-reviewed, highly regarded... looks like they also make on-wall subs... http://www.jamesloudspeaker.com/inwall.cfm

[Patt]

Hi Stephen,

What Snap said about carpet for insulating is a great idea.

My sub shook things severely until I did the following.....sub on spikes...then a round concrete pad painted flat black from a home store....then a dozen squash balls painted flat black and hotmelt glued to the underside of the concrete pad.

It stopped all shaking caused by the movement from the sub. As long as there is room for the sub to be raised about 5"-6".

[Snap]

If you are going to go with an in-wall sub go with Earthquakes new in wall sub that thing is a killer.

Patt what a great Idea. Dang....what a great idea. Thanks man that is cool. I am printing that one out for the ole, file cabinate. :T

[ajpoe]

may be you could get some ideas from this site:

cult of the infinitely baffled

I don't know if it would be possible to seal that cabinet and port it, or just go with something like they have done on that page.

[Patt]

Gee, the guy not only installs subwoofers but builds them as well.......

Thought I spotted a single black Tyler Acoustics monitor speaker on page 3.

[whmacs]

Hi Guys,
Thanks for all the reply's I really appreciate it. I would dearly love to move the sub out of the cupboard, but that would have a very low WAF factor. The first thing I checked was the cupboard doors which turned out not to be the problem. The rattling still occured with the doors open. I'm using DVE's 15hz to 150Hz LFE sweep and the rattling starts at 28Hz and finishes at 38hz so its not the biggest problem, but I would like to try and improve the situation. I've now got some foam rubber and I've grab a paving slab in the morning. I also picked up a couple of carpet tiles so I'll give them a try as will and report back.

Patt, with the squash balls did you cut them in half before sticking onto the the paving slab?

thanks again for all the help guys.

cheers,
Stephen

[eddiem67]

You might have a spike at that frequency, is your sub EQ'd, you can try to flatten the response, although this will not fix your problem, but it might reduce the vibrations due to resonant frequency at 28-38Hz. The earthquake in wall subs are very nice, that is one recommendation, or you can get a baffle sub, ie Image dynamics.

[whmacs]

Hi All,
First off I would like to thank everyone for all the great ideas and suggestions, this is a great forum to be a member.

Well after everyone's suggestions the problem turned out to be fairly easy to fix. Last night I confirmed that there were no loose items rattling and it was in fact the cabinet resonating. Following peoples suggestions I ended up lining the inside of the subwoofer enslosure with carpet tiles which cost about $5 per 0.5metre square tile (the enclosure is roughly 0.5 x 0.5 x 05). Problem solved! I can detect no reasonance now in the 28 - 38hz range at normal listening levels (around 62 on my Rotel RSP-1098 procesor) and I can't detect any loss of subwoofer impact due to the carpet tiles! To induce any hint of vibration I have to crank the RSP-1098 up to 75 or so. At this level there is only a hint of vibration in the 28 - 38Hz range and no vibrations in any of the other ranges. 75 is way too loud and I have the automatic volume lockout set to 77 to stop the kids blowing things up or the sub causing down lights to fall out of the ceiling (which has happened in the past!)

So once again thanks for all the input and suggestion which helped solve the issue.

cheers,
Stephen

[Snap]

:T Glad that worked for you man. I wish I had your system very nice set up!

[whmacs]

:T Glad that worked for you man. I wish I had your system very nice set up!

Thanks Snap I appreciate the kind words. When we built the extension onto the house I had the luxury or designing the room with a HT in mind, this made things a lot easier than trying to retrofit into an existing room.

Once again, thanks for all the help.

cheers,
Stephen