SOLD F/S: AK Swarm- 4 passive subwoofers shipping included $600 SOLD

opnly bafld · « **on:** 29 Aug 2008, 09:32 pm »

SOLD For Sale: Audio Kinesis Swarm- 4 passive subwoofers, oak finish, still in shipping crates.
Purchased for a second system, but now need the money more than the subs.

Link for info: http://www.audiocircle.com/index.php?topic=57519.0

$600 includes shipping and Paypal fees.

Thanks,
Lin

pbrstreetgang · « **Reply #1 on:** 29 Aug 2008, 09:38 pm »

Hi what did you use to power them? What is the size of the woofer and I couldnt find any FR plots or F3s. Thanks

opnly bafld · « **Reply #2 on:** 29 Aug 2008, 09:45 pm »

Quote from: pbrstreetgang on 29 Aug 2008, 09:38 pm

Hi what did you use to power them? What is the size of the woofer and I couldnt find any FR plots or F3s. Thanks

I never opened the crates up, but wired together they present a 4 ohm mono load.
All that I know about them is in the link, maybe Duke can help with your questions.

Lin

opnly bafld · « **Reply #3 on:** 11 Sep 2008, 10:12 pm »

Duke · « **Reply #4 on:** 12 Sep 2008, 04:58 am »

I just now found this thread. I am the builder of the Swarm.

Okay, the passive Swarm modules opnly bfld has for sale are "flat" down to about 25 Hz, if we assume 3 dB per octave room gain below 100 Hz. I designed them this way because most subs end up sounding too heavy and sluggish in part because of room gain.

The woofers are 6.5" units with an unusually long excursion (about one inch peak-to-peak). With the tuning they have, they are not excursion-limited below 150 watts input each all the way down to 20 Hz (600 watts for the quartet).

By distributing the subs asymmetrically around the room, you get significantly smoother bass throughout the room than you would from a single sub, or even two subs symmetrically placed. Smoother bass means better pitch definition and better tonal balance - bass drums have natural impact, bass instruments have natural tonal balance. This technique gives you dipole-like smoothness along with the impact of a good, tight box system.

Let me quote the person I learned about multiple subwoofers from, Dr. Earl Geddes:

"Typical [rooms] have uneven low frequency response. The modal response of rooms at low frequencies causes large peaks and dips in the overall response of a system. EQ is not effective in eliminating these response anomalies.... By using multiple subs distributed around the room, low frequency response can be smoothed out. Placing multiple subs in multiple locations, each sub will excite the room’s modes in a different way. While the response of each would still have the anomalies suggested above, the total combined response is much smoother than any of the individual responses. In essence, they balance each other out, resulting in a much smoother overall response."

The least expensive amplification I'd recommend is a single 240-watt Dayton amp from Parts Express. This amp has a 4th order low-pass filter, which rolls off the top end of the subs rapidly enough that you can distribute them freely around the room as long as you don't cross over any higher than 80 Hz or so. The preferred amplification is a 1000-watt shelf-mount amp also sold by Parts Express; just don't go nuts or you could theoretically overdrive the woofers with this much power.

I'd be more than happy to discuss amps & setup with whoever ends up buying these.

Duke

TRADERXFAN · « **Reply #5 on:** 12 Sep 2008, 02:44 pm »

So Duke,

In this design of yours, are you switching polarity on some of the subs to get better response/integration? Also wasn't the Geddes approach to take the multiple LF sources up into the 150 hz range?

Just curious. I am not understanding how this would work off of one amp.

-Tony

opnly bafld · « **Reply #6 on:** 12 Sep 2008, 05:01 pm »

Quote from: TRADERXFAN on 12 Sep 2008, 02:44 pm

So Duke,

In this design of yours, are you switching polarity on some of the subs to get better response/integration? Also wasn't the Geddes approach to take the multiple LF sources up into the 150 hz range?

Just curious. I am not understanding how this would work off of one amp.

-Tony

I believe they are 4 ohm drivers wired series/parallel to be run @ 4 ohms mono.

Lin

Duke · « **Reply #7 on:** 12 Sep 2008, 05:50 pm »

Traderxfan, Lin is correct, these are 4-ohm modules wired in series/parallel.

You can see the hookup pattern in a photo in this thread:

http://www.audiocircle.com/index.php?topic=57519.0

If you wanted to run two of the modules up to 150 Hz you could, but then you'd need two amplifiers. I haven't tried it.

My adjustment procedure is much simpler than Geddes' - the subs all adjust simultaneously from one set of controls (assuming you use one amp to drive them all). A few minutes with a good natural recording like the Sheffield Drum and Track disc, then double-check the level with another disc or two, and you're ready to rediscover the basslines in your collection.

Currently, in my room I have left front and right rear sub in one polarity, and right front and left rear in the other. This x-polarity was first described by Jennifer Crock, to the best of my knowledge.

My wife has a CD of a group called Bella Sonus that has a lot of heavy bass synthesizer on it. With large speakers and no Swarm in my living room, the bass blooms too much for my taste and I can't enjoy the disc. With the Swarm (and smaller main speakers) the bass is solid and defined, and those frequencies don't bloom and overpower the rest of the music.

Duke

opnly bafld · « **Reply #8 on:** 13 Sep 2008, 10:03 pm »

opnly bafld · « **Reply #9 on:** 15 Sep 2008, 09:57 pm »

opnly bafld · « **Reply #10 on:** 23 Sep 2008, 01:23 am »

bump for lower price

James Romeyn · « **Reply #11 on:** 23 Sep 2008, 03:51 am »

That is an insanely great deal.

I humbly beg someone to buy these before I do; I just don't have a need for them because of my own four sealed 10s.

A thread ended several weeks ago describes my experiments w/ Geddes/LeJeune's multiple sub techniques. Summary is it makes for great bass sound in a room that otherwise has such bad modes that virtually any other sub would be intolerable. I owned a $3k MSRP value sub w/ EQ. The worse your room modes the better the advantage.

I am currently using four subs w/ one amp. On two of the subs I added a series coil value to slightly stagger (lower) the XO pole vs. the other two subs. The subs are arranged in a random X-pattern, the subs generally located in the L-front/R-rear are out of phase w/ the R-front/L-rear. Results are outstanding, esp in natural bass integration. In "space" & "dimensionality" the bass is unmatched except for maybe huge ultra-costly bass towers w/ four to eight drivers per side. You would NEVER believe listening to it that the xo is set around 150 Hz.

Overall it beats the results of several thousand dollars (retail value) of acoustic soffit at my last room.

It's worth the effort; Duke's little subs won't take up as much space as room treatments & IMO the results are better. Again, the worse your modes the better the results.

Some TT owners have given up on low bass because of feedback from room modes. This bass technique solves that issue because the bass is so linear. Mode effects are practically non-existent in this room now.

JDUBS · « **Reply #12 on:** 23 Sep 2008, 04:11 am »

PM'd.

-Jim

ooheadsoo · « **Reply #13 on:** 23 Sep 2008, 05:04 am »

Wow, good deal. If I didn't have so many things on my plate...

opnly bafld · « **Reply #14 on:** 23 Sep 2008, 08:45 pm »

JDUBS · « **Reply #15 on:** 24 Sep 2008, 02:20 am »

Sweet! Looking forward to these.

Russell Dawkins · « **Reply #16 on:** 24 Sep 2008, 03:03 am »

Congratulations! Tell us how they work for you, please.

JDUBS · « **Reply #17 on:** 24 Sep 2008, 03:11 am »

Absolutely, Russell! Should be interesting with the Yorkville's.

-Jim

Russell Dawkins · « **Reply #18 on:** 24 Sep 2008, 03:27 am »

when do you get the Yorkvilles - or do you already have them?

JDUBS · « **Reply #19 on:** 24 Sep 2008, 04:07 am »

Not yet. Got the source, amps, and (now) sub solution. I figure the Yorkville's have always bee the easiest piece of the puzzle. Will be ordering them within the week.

-Jim