Need help from subwoofer experts?

How do I set up my 15" 1000 watt Velodyne sub (DLS-5000R) to sound the best. It’s a front driver and in a 375 sq ft carpeted room with 2 puffy couches and chair, with a 7′ 9" ceiling height. Where should I put it in the room and how do I know what phase (0,90,180,360) to set it at? What should I have the low bypass set at if my main speakers (240 watt 5"woofers) can’t handle a ton of bass? I would be happy with a rough starting point and fine tune it from there.

A common way to locate the best location for a subwoofer in a room is by the reciprocal method. This works by placing the sub in place of your favorite listening chair and then crawling around the room investigating possible locations by simply listening. If you find a spot where you feel it sounds its best then the reciprocal will also be true. That is you can move the sub to that position and then your favorite listening chair will be in an equally optimum location.

Don’t listen to those that will tell you to just stick it in any corner. There is madness to that reasoning…or is it reasoning to that madness…??? but it’s a big over simplification of the problem. The idea of the corner is to reduce the perceived space seen by the sub. Sitting in the middle of an open area on the floor is a half space or 2 pi environment whereas suspended in the air would be a full space or 4 pi environment. Against a wall…1 pi, a corner half pi… Or you could look at it like the walls forming a big horn…ultimately the same thing. This will be great for some locations in the room but those locations are arbitrary and unknown. When you place the sub in place of your favorite listening chair and then crawl around the room in search of the optimum performance you may very well find that it is in a corner but probably not.

I’m not familiar with that particular subwoofer in fact I don’t deal much with commercially built subs of any brand because I never heard one I liked. If it does not have any sort of automatic room mode correction built in you may want to consider this as an add on. Personally I would just use a Behringer DCX2496 and dial it in manually using Arta or any other decent measurement system but not having experience you may want to use an automatic one. I just don’t trust those things especially after the horrific experience I had with the Anthem ARC. What a nightmare! What a screw up that thing is!

You could mess around with bass traps too but I personally wouldn’t bother, I would just EQ it either with an automatic room correction or preferably a manual one. This will make a bigger difference than you think. If you saw some response curves of low frequency in a room you would understand why this is so desperately needed. If you understand how sine waves are added think about it. Think about how reflections off walls etc will impact the response as you move through frequencies and you will understand why the response is so messed up and needs corrections. Also, if you can swing a second one of those things it will make it easier to get good uniformity in the room.

Oh yes, start with the phase in the 0 deg positon. If the optimum spot isn’t optimum cosmetically or in any other respect you might be able to use the phase knob to shift the optimum position somewhat to make things work out better.

Edit: On your mains, with 5" woofers I definitely would not go below 80 Hz and maybe not even that low. You may want to stay over 100. With a sub like that you should get some bigger mains.

2 Responses to “Need help from subwoofer experts?”

  1. A common way to locate the best location for a subwoofer in a room is by the reciprocal method. This works by placing the sub in place of your favorite listening chair and then crawling around the room investigating possible locations by simply listening. If you find a spot where you feel it sounds its best then the reciprocal will also be true. That is you can move the sub to that position and then your favorite listening chair will be in an equally optimum location.

    Don’t listen to those that will tell you to just stick it in any corner. There is madness to that reasoning…or is it reasoning to that madness…??? but it’s a big over simplification of the problem. The idea of the corner is to reduce the perceived space seen by the sub. Sitting in the middle of an open area on the floor is a half space or 2 pi environment whereas suspended in the air would be a full space or 4 pi environment. Against a wall…1 pi, a corner half pi… Or you could look at it like the walls forming a big horn…ultimately the same thing. This will be great for some locations in the room but those locations are arbitrary and unknown. When you place the sub in place of your favorite listening chair and then crawl around the room in search of the optimum performance you may very well find that it is in a corner but probably not.

    I’m not familiar with that particular subwoofer in fact I don’t deal much with commercially built subs of any brand because I never heard one I liked. If it does not have any sort of automatic room mode correction built in you may want to consider this as an add on. Personally I would just use a Behringer DCX2496 and dial it in manually using Arta or any other decent measurement system but not having experience you may want to use an automatic one. I just don’t trust those things especially after the horrific experience I had with the Anthem ARC. What a nightmare! What a screw up that thing is!

    You could mess around with bass traps too but I personally wouldn’t bother, I would just EQ it either with an automatic room correction or preferably a manual one. This will make a bigger difference than you think. If you saw some response curves of low frequency in a room you would understand why this is so desperately needed. If you understand how sine waves are added think about it. Think about how reflections off walls etc will impact the response as you move through frequencies and you will understand why the response is so messed up and needs corrections. Also, if you can swing a second one of those things it will make it easier to get good uniformity in the room.

    Oh yes, start with the phase in the 0 deg positon. If the optimum spot isn’t optimum cosmetically or in any other respect you might be able to use the phase knob to shift the optimum position somewhat to make things work out better.

    Edit: On your mains, with 5" woofers I definitely would not go below 80 Hz and maybe not even that low. You may want to stay over 100. With a sub like that you should get some bigger mains.
    References :

  2. Maniac is actually correct (good answer).

    A good starting point is to find the corner with the longest un-broken walls. Pick the longer wall and move the sub in 2/5 or 1/3 as the rough starting point. Move the sub between these 2 points to try and get smooth bass at your seats.

    Leave the phase to 0. Moving the sub an inch or two is a better way to adjust.

    Low bypass: set to max so your receiver will take care of this. Tell your receiver your other speakers are SMALL so all bass will be routed to the sub. In general - you want 1 source of bass in a room to avoid complex interactions.
    References :

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