[brother love]

I've written a freeware called Multi-Sub Optimizer to help with this problem.  There's a thread about it here ...

Thanks andy_c,  I downloaded your app & will look into it further once I get down & dirty with measuring a bunch of stuff.

[Odal3]

The fun part is trying out a lot of things, so go for it.

@andy_c  that sounds interesting - need to check it out. Perhaps worth a thread on it's own so more people can hear about it.

[mresseguie]

Bucket subs ( piano black special ordered from Home Depot ) and Yung SD300 plate amp.

Awesome! Those look a lot better than the white or orange buckets I had imagined using. 

[Poultrygeist]

I've now added black grills to the bucket sub which look even better and offer some protection. The 12" lattice grills from Parts Express are a perfect fit and snap snugly in place inside the rim. You can hardly tell they started life as 5 gallon buckets. The chrome trim on the buckets is plastic automotive door molding.

As to the question regarding daisy chaining the plate amps, my Yungs are pass through and I would think most are. This means the line outs pass the original signal unchanged. Raising the volume on one plate amp does not affect the other when daisy chained together.

[brother love]

Update:  I forged ahead following the Earl Geddes subwoofer swarm approach & acquired (3) subwoofers to experiment with.  Purchased off local Craigslist: 12" Kenwood/ 10" Polk/ 8" Athena Tech powered subs for $140 plus $35 of cables purchased from Amazon, so $175 invested.

Fortunately my Grant Fidelity TubeDAC-11 dac/preamp allows tube out for my GR Research N-3 transmission line mains run full range & line out for the (3) subwoofers hooked-up with Y adapters & RCA cables.

I tried 8 total sub locations (4 front & 4 back) before arriving at the best solution: 8" sub front wall corner 4' above floor & 2-stacked 10"/12" subs on back wall behind listeners chair:





Measurements were taken from the center listening chair "sweet spot" since I am the one doing the primary listening. Again 2 ch mains were run full range. Many measurements later, optimum results were achieved with 8" front sub set at 65 Hz/ 12" bottom back sub 85 Hz/ 10" top back sub 80 Hz. All sub volumes were set low (more or less 2 of 10 max). Improvements are quite encouraging for 3 subs vs. no subs:



Note that the 2 channel/ no sub measurement was the absolute best that I could achieve in my room after countless speaker placements & $800 worth of sound treatments: http://www.audiocircle.com/index.php?topic=133947.0

I have done some before & after listening comparisons, & for my modest $5k mid-fi system, the 3 multi-sub set-up definitely improves the overall sound.  I also took measurements with 1 sub & 2 subs that I will post later for comparative purposes. My conclusion is that Dr. Geddes was on to something with this subwoofer swarm thing ... 

[ACHiPo]

Great progress!  Have you adjusted phase, gain, and damping on your subs to minimize peaks and nulls?

[brother love]

Best measurement results were front sub at normal phase & the 2 back subs set at reverse phase. All 3 sub amp gains were played with until they all ended close to 2+ or - of 10 max. No damping factor settings available on these CHEAP & cheerful subs. 

Here is the 0- 3 sub measurements comparison:

[poseidonsvoice]

As a serious adopter of multisubs, I want to congratulate you for what you have accomplished and for using 1/24th octave smoothing!

Best,
Anand.

[brother love]

Thanks ACHiPo & Anand.

[brother love]

Update/ full disclosure:

I have done more extensive listening sessions with & without Cheap & Cheerful (3) subwoofer set-up outlined previously in this thread, & reached some interesting conclusions re: soundstage with GR Research N-3 transmission line speakers spaced 7 ft. apart:

without multi-subs:  7 ft. c-c speaker mains + approx. 1.5 ft. wider per speaker = 10 ft. wide soundstage

with (3) multi-sub set-up: 7 ft. c-c speaker mains - approx. 0.5 ft. narrower per speaker = 6 ft. wide soundstage 

Soundstage depth is a bit better with the (3) multi-sub set-up (fuller, better low end detail)

Maybe it is the Grant Fidelity TubeDAC-11 DAC/preamp limitations (utilizing tube out for mains & line out for (3) subs in series), but not sure ...

Not sure what my next step is, but keeping an eye on the Crown XLS-1500 close-out prices. 

[Folsom]

do you have the widths backwards?

[brother love]

do you have the widths backwards?

Nope, as written. It's a bit puzzling to me, too.


 vvv  Odal3,  Only way I know of is by ear. I took 3 songs & did A-B comparison for each song.  vvv

[Odal3]

How do you measure soundstage width?