Multiple Subwoofer Placement

[cjfrbw]

Well, I continue to be impressed by the Geddes array.

With two subwoofers, the sound is a warm, embracing tide.

When the third above ear sub is engaged, the bass takes on a profound Prussian discipline. It is taut, tight, disciplined and subtle.

With all three subs engaged, it is nearly impossible to not listen to the bass line when it is present, it is just really THERE.

If I want the warmer, more wavering hippie dude bass, I just have to turn the small above the ear sub off.

Cool.

 

[brianherlihy]

is it possible to get pictures of the sub set up with those who are employing the Geddes principle. i am very interested by this.
thanks

 

[Steve Williams]

is it possible to get pictures of the sub set up with those who are employing the Geddes principle. i am very interested by this.
thanks

Me too

 

[DWR]

Are you guys looking for a picture that shows the subs physical locations in the room?

 

[FrantzM]

I was trying to attach a simple jpeg drawing but it came out wrong ... sorry ...

 

[DWR]

OK here are a couple of shots that I have on my computer now if you want another overall picture let me know. The first picture shows the 15" and 18" subs the 15 above the left sono tube sub and the 18 behind the right Abbey and to the right of the right sono tube sub. The sono tube subs are for lfe only and only used for movies obviously. The second picture just barely shows the third sub, it is on the extreme far right of the picture and looks like a dark picture frame you can only see about 30% of it in the pic. The only part you see of that third sub in the room is the grille and frame it is flush with the wall. The entire sub enclosure is behind the wall which is a coat closet the height of that sub is 53" and it is a 12" ported sub.

 

[cjfrbw]

1,2, 3 are subwoofer positions, with 3 being above ear level. Listening seat is indicated "seat", this is in a room about 19x13.5 ft with a dog leg to the left (not depicted).

Main speakers are opposite the listening seat into the room about four feet (planar speakers) out from the front wall a little bit further apart than subwoofers 2 and 3 on the back wall and equidistant from the seating position.

 

[brianherlihy]

thanks CJFRBW and DWR. CJFRBW, i am curious to know where the dog leg is as i also have a dog leg behind my sitting position. did that impact the placement of the subs. To both of you, have you tried Geddes solution of having one sub halfway between your sitting position and the speakers? My listening room is 19 x 40 x 10.5 (slanted ceiling) with the first 20 of the 40 enclosed and behind my listening position i have one wall open (dog leg) to the larger loft.

 

[DWR]

No I have not as it is pretty much not an option in my room. The fireplace being on the left side and the love seat on the right leaves me no real way to locate a sub in either location. I have thought of and may try moving the left side sub out next to the fireplace but that only gets it about 4 feet out further than it is right now.

Dan

 

[Nyal Mellor]

Assuming everyone is running the subs overlapping with the mains...what frequency are you low passing the subs at?

 

[FrantzM]

Hi

Trying one last time:

Seems to work this time
..

 

[DWR]

72 hZ here, I run the mains full range and send the second full range signal from the preamp to the subs via a DCX-2496, the Abbeys start to roll off pretty quickly under 50 hZ. I have gone anywhere from 100 hZ to 50 hZ and found the bass sounds the best at the 72 hZ level. I delay the 3rd sub 5.82 mS to make up the distance difference and run all 3 subs 90 degrees out of phase with no EQ right now.

Dan

 

[DWR]

Frantz, I really wish I could get my second sub right in the location you show on your diagram, but I have no way of doing that in my room.

Dan

 

[cjfrbw]

thanks CJFRBW and DWR. CJFRBW, i am curious to know where the dog leg is as i also have a dog leg behind my sitting position. did that impact the placement of the subs. To both of you, have you tried Geddes solution of having one sub halfway between your sitting position and the speakers? My listening room is 19 x 40 x 10.5 (slanted ceiling) with the first 20 of the 40 enclosed and behind my listening position i have one wall open (dog leg) to the larger loft.

New diagram, not absolutely to scale, with dog leg. I don't really let the dog leg influence my positioning of equipment, the room has a sloped ceiling for a trapezoidial cross section, but I think the dog leg acts as a good "mixing chamber".

 

[Gedlee]

Are you guys looking for a picture that shows the subs physical locations in the room?

Yea - none of my subs are normally visible, so what would a photo mean?

 

[Gedlee]

Assuming everyone is running the subs overlapping with the mains...what frequency are you low passing the subs at?

All three of my subs LP at different frequencies. In general, since the LP is part of the "EQ", I would expect them to all be different.

 

[DWR]

OK I took a better picture today showing the location of the third sub, as you can see all that you see is the grille and frame.

Dan

 

[Nyal Mellor]

All three of my subs LP at different frequencies. In general, since the LP is part of the "EQ", I would expect them to all be different.

What is the methodology to select the LP frequency for the different subs, assuming one has access to high resolution acoustic measurement equipment?

 

[brianherlihy]

@ Frantz

i sent you a message but stated that your mailbox was full

 

[FrantzM]

Brian

Just cleaned it and replied to you ...