HELP! parents+rattles= bad

[xstephanx]

Well currently im using one low quality 10" in a 1.5 cu ft enclosure tuned to 27hz. This thing doesn't even move alot of air, but its enough so that its really loud in the livingroom below, and the light fixtures on the floor below tend to rattle aswell. How do i minimise this? i want less sound on the floor beneath and to prevent rattles on the ceiling below my floor. Any help would be welcome as im soon moving up to a 15" in a 7 cu ft box, with a 20hz tune and gobs of power, and im sure ill need all the help i can get from being evicted from my own house.

[joe carrow]

Everything I have read so far makes me want to tell you "Dipole!!!"

[xstephanx]

Thats unusual cause my bank account tells me PORTED/SEALED. Plus this is mainly for HT and i want a strong resonse down to 20hz. Yes yes yes, ive seen the now famous chops/pyle dipoles with infrasonic output, but no money.

[joe carrow]

If you haven't bought the drivers yet, you can look over here- http://home.insightbb.com/~stephenwm...nix_Update.htm

The only other thing I could suggest, if you want to reduce rattles, is to consider using two 12"s instead of a single 15. This way you could have them in a Bi-pole configuration, so that the reaction force of one driver cancels that of the other and there's less cabinet shaking.

Another thing that one might suggest would be the idea of cutting two tenis balls in half and placing them under the sub to physically isolate it from the ground.

Also, horns have directional bass. If you haven't already spent your cash on the "gobs of power", you could probably make a pretty sweet horn in 7 cubic feet that would be as quite loud on 25 watts, and get you evicted at 200 watts.

Joe

[xstephanx]

ive already got the sonotube in my garage, and once again i want it to get down LOW into 20 hz bass, cheap dipoles wont do that without GOBS of equalisation. and horns take lots of trickey woodwork. im using a dayton quatro so my budget is low, about 160 cad shipped, cause after this I need a 5.1 reciever. Once again this iis for MOVIES not music.

And ill try that tennis ball idea
what about those spike ma bobers? what they do?

[joe carrow]

Ah, more info is good

The spikes are (as I understand it) supposed to let the cabinet get a better grip on the ground, so the cabinet moves less.

When a speaker is pumping away, the moving mass of the cone has to have some sort of opposing force- for every action there is an equal and opposite reaction. That means that if there was no friction with the ground, and the moving mass of the speaker is 1/10 the weight of the cabinet (unrealistic, i know)- the cabinet would be moving back and forth 1/10th as far as the speaker cone, relative to the room! Friction prevents this, and if you have spikes, the spikes prevent front-to-back movement by physically holding it in place.

So, for the action of the speaker moving- the reaction is the cabinet pushing on the floor. The pushing on the floor could be one source of transmitting vibrations to downstairs.

Now- another thing that would transmit a lot of vibration to downstairs is if you have the subwoofer firing at the floor. Again, this isn't about sound pressure- it's about the mass of the cone shaking up and down, causing the cabinet to push on the floor.

With a single woofer in a sonotube, I would recommend placing the sub on its side and physically isolating it from the ground. You could do the tennis ball thing, or you could make a small frame and actually let the sonotube be supported in a small sling.

Anyway, those are just my opinions about how to minimize vibrations downstairs. Good luck with the project!

[xstephanx]

*sigh* its looking like there is no miracle cure , ive grown to know there seldom IS in DIY audio. i JUST made a mini sonosub out of a coffe tin and a tangband 5" midbass driver i had lying around. even THAT causes some noise(IF its running at or close to full tilt). after talking to my dad he sais as long as the bass can be talked through, and that one light fixture doesnt rattle hes ok with it. My mom however is a different story, and its not like i can just not watch movies when shes here. although usually i can tell her to "go do laundry" when i watch a movie (so shes in the basement), she still doesnt get that its a joke. Looks like ill try the tennis ball idea.

But ONE last idea, vibration isolators for your comonents? could i put those on my sub and would that work? or is it just a speaker spike.

Also if anyone else has any ideas, consider them welcome. I dont know HOW people in apartments have subwoofers

[BassAwdyO]

You got to play it at a reasonable level when others are around so as not to disturb them. When you're alone and no one's around, go nuts. Sound dissapears after a few seconds and there wont be any evidence of how loud you played. Mechanical vibration from the reactive forces of the driver moving can cause house rattles quite easily. I remember a pair of 12" subs I had in sealed enclosures would take ~200watts @ 30hz to make pictures on the walls rattle when side firing, but when firing vertically it only took half the power. The bass didnt sound any louder either way really, but you could feel it in your body more with the vertical firing. Push push subs will minimize the effects of inertia on your subwoofer enclosure, but if you insist on getting a 15 instead of perhaps 2 12's then you can suffer the vibration.

[xstephanx]

its not a matter of insisting, its a matter of budget. Do you think putting maybe a large concrete slab under my sub to weight the floor would help with the rattles downstairs? id also get a nice hard reflecting surface.

[BassAwdyO]

You cant really reflect the bass frequencys in the same mannor that you can with HF. A concrete slab might help noticably, but its not a gurantee. As for your budget, only you can change it. Its not too unreasonable to find two 12 inch subs for the price of a single 15 and not sacrifice a significant amount of performance.