Subs too big for bedroom

[bigwill]

I've recently built some big TL subwoofers (see this thread) and I just put them in my bedroom

They can get down to about 25Hz with the cones barely moving! But the problem is, you can only hear/feel it if you're right at the opposite end of the room as the subs! This applies to everything below about 40Hz. The lower I go, the further away from the subwoofers I have to get to actually hear the note. My room is terrible! 25Hz is interesting because when you stand right next to the speakers, you can't hear or feel anything, but you can hear stuff in other rooms vibrating

I might try them in the middle of the room, but that will require me to move a lot of my junk out of the way.

Any help would be appreciated

Cheers,

bigwill

[pinkmouse]

Originally posted by bigwill
...but that will require me to move a lot of my junk out of the way.

Any help would be appreciated...

Sorry mate, I don't do lifting!

[DorinD]

Hi Bigwill,
I would make a guess that your description has something to do with different phase of the waves coming from drivers and ports. Could be anything else but this is simple to check; just close the ports and see what's happening.
I'm just thinking to make a TL sub and such situation (big sub in small room) is also my case, so I want to make a try with a closed-ended half-wavelenght TL.
Cheers,
Dorin

[youyoung21147]

They are probably out of phase : it's quite hard to run 2 subs in a small room.

Try switching off one of them, or reverse the speaker's connexion on one of them. Maybe it can solve the problem.

[johnnyx]

FWIW I have experienced this with closed box speakers, so it's nothing to do with ports. The output @ 25Hz measured the same level as that @ 40Hz, yet I couldn't hear bass below 30Hz. Just the way it is with small rooms, I suppose.

[bigwill]

Thanks for the suggestions people I'll try reversing the phase of one of them. This might be the problem, since when you turn on my amp you usually get a thump you can feel even with small speakers, but with these you couldn't

It might just be the room though!

I'll give it a go

Edit: Ok, I just tried it. Music sounds better but suddenly there is NOTHING below 35Hz ANYWHERE! I guess they were in phase in the first place. This is crazy!

[zobsky]

try playing with placement (perhaps with only one turned on for a start)
1. move them away / closer to the rear wall
2. try flipping it to/ bottom so the terminus is at the bottom instead of the top
3. try placement along a wall rather than at a corner
4. try firing the driver at the wall
5. try playing with the amount of stuffing
6. bunch the subs together, .. see if you can get the wavefronts to reinforce each other

other combinations of 1,2,3,4,5,6

something else which i do, and am not sure how useful it is in the context of your issue is to run the subwoofers nearfield as opposed to farfield (however, in your case, the nearfield response is your issue so .. )


it might be useful to run a frequency response test if that's possible.

i had the similar room modes issue in my living room leading to the eventual banishment of any hi fidelity devices from that space

[richie00boy]

I reckon there's nothing wrong with your speakers and it's simply that you have a lot of nulls in your room. Fiddle with the positioning, but in a small room I don't think you'll make huge differences.

[tomtt]

perhaps the subs coud be placed in another room

[bigwill]

I think the problem is the fact that my bedroom is basically a big concrete square!

Luckily, most of the bass seems to be concentated in the corner where my computer is, and it's nice to listen to music while on there, so it's not all bad

Another thing that could make the responce a bit more peaky is the fact that my TLs are unstuffed. I will experiment with this soon!