Sonically, I think Robert E. Greene's review of this subwoofer system in The Absolute Sound nailed this. I've had dual JL Fathom f113 subs as well as other sub pairs, but while the bass from those was certainly strong enough and went at least as low as the Swarm, the quality of the bass produced by the Swarm is in a whole different realm, and the spatial envelopment enhancement provided--especially with two amps driving the woofers in stereo and in quadrature (left woofers 90-degrees out of phase with the right woofers) is something far beyond what the JL pair provided in my old basement concrete bunker room. Even though this is a small room (161" L x 132" W x 103" H) even as USA home listening rooms go, the bass quality is much closer to what I hear in a concert hall than what I've been previously able to achieve at home.
Having had the Swarm set up in my small upstairs stereo room (the one with the Stirling LS3/6 main speakers) for awhile now, I will just offer a few set-up hints and observations not covered in REG's review:
1. The amp(s) AudioKinesis has chosen for powering the Swarm is the Dayton Audio SA1000. One is provided in the now-$2,800 price for the Swarm. If you want two, so you can operate the woofers in stereo, that will cost a few hundred extra. These amps are well-packed and should arrive undamaged. They look and feel more expensive than they are, but don't be expecting sheet metal or cosmetics of the type you get with many multi-thousand-dollar amps.
2. The transformers of the amps may well put out some mechanical 60 Hz hum. Not through the speakers, just directly mechanically from the chassis. My two samples both hum, about equally. They are both attached to the same dedicated 20-amp electrical line. It is not the worst transformer hum, I've heard, but is clearly audible from the listening position and elsewhere in the room. Unlike my old basement concrete bunker room, this second story converted bedroom is not anechoic chamber quiet, either. I live very close to a commuter train line and there is a lot of audible air traffic from O'Hare, as well as vehicular traffic on my street. I still clearly hear the hum. None of the other components in either of my stereo systems produce any audible transformer hum.
3. This transformer hum was totally eliminated by plugging both amps into a single Audio by Van Alstine Humdinger with the Hundinger plugged directly into one of the wall sockets which previously powered the Dayton amps. That Humdinger device costs $140, plus shipping.
4. The speaker terminals (as well as the port) for the Swarm woofers are on the bottom of the cabinets. The one-inch-tall feet will give adequate floor clearance if you are using bare or tinned wire, pins, spade lug connections or normal banana plugs. However, with the extra-long locking banana plugs on my Blue Jeans 10 White speaker cables, you will want taller feet to prevent the long, inflexible locking banana from touching the floor and perhaps creating stress on the plug connection or allowing some rocking of the cabinet. The angled entry of the locking bananas into the binding posts gets the cable end of the bananas very close to or in fact touching the floor a bit. Fortunately, drop-in replacement 1.5" tall feet are inexpensively available from Parts Express here. The mounting screws AudioKinesis supply are long enough to work fine with these taller feet. The taller feet provide plenty of clearance even for the Blue Jeans locking bananas. I'm using these taller feet.
5. Two of the woofers have two sets of binding posts. The other two woofers have only one set of binding posts. You hook two of the woofers in series connection by connecting the woofer with two sets of binding posts to the amp and then connecting that woofer to a woofer which has only one set of binding posts. Hot goes to hot in all connections; the series connection part is taken care of via connections within the woofer box so as to prevent the hookup from being any more complex than necessary for the user.
6. Here are some additional details about the Swarm set-up I've taken from an email Swarm designer Duke LeJeune sent me in response to my questions:
7. Given my small, relatively bass-retaining room, I have all the ports closed and all the woofers facing the wall as Duke recommended. The "golden ratio" set-up diagram is attached. In my room, I am able to get all the woofers except the .15L one placed as specified in the diagram. For that one, I currently place it as closely as possible to the recommended position. To get it at .15L, I'd have to move the right Stirling further away from the side wall than it is now so that the Swarm woofer could fit between the side wall and the Stirling.
8. The Swarm set up has given me more reasons to love the Lyngdorf TDAI-2170 which powers the Stirling LS3/6s in this system. The Lyngdorf's main speaker outputs, its analog line-level outputs, and its digital outputs are all independently adjustable in terms of level, high pass or low pass filtering, crossover frequency (Hertz by Hertz precision), and crossover slopes (choices of 1st-order, 2nd-order, or 4th-order Butterworth or 8th-order Linkwitz-Riley). All these functions are executed by the Lyngdorf in the digital domain. These controls are in addition to the analog high- and low-pass crossover, parametric EQ, phase, and gain controls of the Dayton subwoofer amps. In my system, there are obviously a lot of possibilities to explore in terms of integrating the Swarm with the Stirlings.
9. So far, I have been using the LS3/6 as REG apparently did--full range. So far I like the full and punchy bass quality of the Stirlings and don't want to diminish that quality. With my current speaker and listener positioning, they produce rising output down to 45 Hz and produce usable but diminishing output down to around 30 Hz, as measured by the Omnimic system.
10. I do like the sonics and measured response of the Swarm system best so far using the 4th-order Butterworth low pass of the Lyngdorf. The 1st- and 2nd-order slopes affect the measured range above the crossover too much for my liking. The 8th-order L-R crossover sounds a bit "strange." I bypass the Dayton amp's analog crossover by feeding the analog line out of the Lyngdorf into the LFE inputs of the Dayton amps. That definitely makes the subs sound a bit cleaner than feeding the signal through the Dayton's analog low-pass filters. I have been adjusting the crossover frequency and slope using the Lyngdorf's digital controls.
11. I have been using the Dayton's analog gain control to adjust the overall level of the subwoofers. This is actually easier to adjust while watching the real-time Omnimic measurement display than is watching the display while changing the analog output level of the Lyngdorf.
12. I have not yet tried the Dayton amps' parametric notch filter to attack the primary bass resonance. In my room, the biggest resonance seems related to the floor-to-ceiling mode and is in the 70 Hz range. With my current speaker placement, however, this resonance is not very noticeable sonically and measurably.
13. I adjust the phase for quadrature using the phase control on the Dayton amps. There are many ways to do this, but works for this system is as simple as leaving the left channel amp phase control at zero degrees and setting the right channel amp phase control to 90 degrees.
14. In this system, in this room, with the Swarm set up as described, the response of the system measured with the Omnimic is basically a pretty flat line from 20 Hz up to the chosen crossover point. In my current arrangement, I have the crossover set at 45 Hz. In prior set-ups, I had it set as high as 60 Hz and as low as 40 Hz.
15. If I want a higher crossover from subs to Stirlings, I would high-pass the main speaker outputs from the Lyngdorf at a chosen frequency and low-pass the analog output of the Lyngdorf at that same frequency. That would be a way to erase some of the low-frequency room lift I'm getting right now since the lift is coming from the Stirling output into the room, not the Swarm output, which is basically a flat line as configured.
Having had the Swarm set up in my small upstairs stereo room (the one with the Stirling LS3/6 main speakers) for awhile now, I will just offer a few set-up hints and observations not covered in REG's review:
1. The amp(s) AudioKinesis has chosen for powering the Swarm is the Dayton Audio SA1000. One is provided in the now-$2,800 price for the Swarm. If you want two, so you can operate the woofers in stereo, that will cost a few hundred extra. These amps are well-packed and should arrive undamaged. They look and feel more expensive than they are, but don't be expecting sheet metal or cosmetics of the type you get with many multi-thousand-dollar amps.
2. The transformers of the amps may well put out some mechanical 60 Hz hum. Not through the speakers, just directly mechanically from the chassis. My two samples both hum, about equally. They are both attached to the same dedicated 20-amp electrical line. It is not the worst transformer hum, I've heard, but is clearly audible from the listening position and elsewhere in the room. Unlike my old basement concrete bunker room, this second story converted bedroom is not anechoic chamber quiet, either. I live very close to a commuter train line and there is a lot of audible air traffic from O'Hare, as well as vehicular traffic on my street. I still clearly hear the hum. None of the other components in either of my stereo systems produce any audible transformer hum.
3. This transformer hum was totally eliminated by plugging both amps into a single Audio by Van Alstine Humdinger with the Hundinger plugged directly into one of the wall sockets which previously powered the Dayton amps. That Humdinger device costs $140, plus shipping.
4. The speaker terminals (as well as the port) for the Swarm woofers are on the bottom of the cabinets. The one-inch-tall feet will give adequate floor clearance if you are using bare or tinned wire, pins, spade lug connections or normal banana plugs. However, with the extra-long locking banana plugs on my Blue Jeans 10 White speaker cables, you will want taller feet to prevent the long, inflexible locking banana from touching the floor and perhaps creating stress on the plug connection or allowing some rocking of the cabinet. The angled entry of the locking bananas into the binding posts gets the cable end of the bananas very close to or in fact touching the floor a bit. Fortunately, drop-in replacement 1.5" tall feet are inexpensively available from Parts Express here. The mounting screws AudioKinesis supply are long enough to work fine with these taller feet. The taller feet provide plenty of clearance even for the Blue Jeans locking bananas. I'm using these taller feet.
5. Two of the woofers have two sets of binding posts. The other two woofers have only one set of binding posts. You hook two of the woofers in series connection by connecting the woofer with two sets of binding posts to the amp and then connecting that woofer to a woofer which has only one set of binding posts. Hot goes to hot in all connections; the series connection part is taken care of via connections within the woofer box so as to prevent the hookup from being any more complex than necessary for the user.
6. Here are some additional details about the Swarm set-up I've taken from an email Swarm designer Duke LeJeune sent me in response to my questions:
The way to connect two subs in series is this: Connect one set of speaker cables from amp to the "lower" set of inputs on a dual-input sub, and then connect another set of speaker cables from the "upper" input set on that sub to a single-inputs sub. Internally, the two "-" tabs on the dual-input terminal cup are jumpered to one another, and the lower "+" input goes to the + terminal on the woofer while the upper "+" input goes to the - terminal on the woofer. At this link is a picture of the terminal so that you can see what I mean by "upper" and "lower" sets of inputs:
The number of ports that should be open or plugged depends on how much low-end reinforcement your room provides. If it's a small dedicated room where you normally listen with all the doors closed, then you're probably going to want to plug all the ports. If it's a large and/or "open floorplan" room, then you're probably going to want most if not all of the ports open. In your case, I'd start with them all plugged.
When you remove a plug, make sure you also remove the black rubber threaded piece, as that's part of the plug, not part of the port.
I normally face the woofers at the wall because this way they just look like blocks of wood on little feet, and I think that's kinda cool. Not many subwoofers look like that. Also, that saves me the trouble and expense (and hence saves you the cost) of grilles. I hate doing grilles.
If you have total freedom to place the subs as you see fit, you might want to try the "golden ratio" configuration shown on the attached drawing. Don't worry if you can't do it exactly, as the effective room dimensions at low frequencies will be different from the room's actual physical dimensions anyway.
And definitely try the two sides in "phase quadrature"!
7. Given my small, relatively bass-retaining room, I have all the ports closed and all the woofers facing the wall as Duke recommended. The "golden ratio" set-up diagram is attached. In my room, I am able to get all the woofers except the .15L one placed as specified in the diagram. For that one, I currently place it as closely as possible to the recommended position. To get it at .15L, I'd have to move the right Stirling further away from the side wall than it is now so that the Swarm woofer could fit between the side wall and the Stirling.
8. The Swarm set up has given me more reasons to love the Lyngdorf TDAI-2170 which powers the Stirling LS3/6s in this system. The Lyngdorf's main speaker outputs, its analog line-level outputs, and its digital outputs are all independently adjustable in terms of level, high pass or low pass filtering, crossover frequency (Hertz by Hertz precision), and crossover slopes (choices of 1st-order, 2nd-order, or 4th-order Butterworth or 8th-order Linkwitz-Riley). All these functions are executed by the Lyngdorf in the digital domain. These controls are in addition to the analog high- and low-pass crossover, parametric EQ, phase, and gain controls of the Dayton subwoofer amps. In my system, there are obviously a lot of possibilities to explore in terms of integrating the Swarm with the Stirlings.
9. So far, I have been using the LS3/6 as REG apparently did--full range. So far I like the full and punchy bass quality of the Stirlings and don't want to diminish that quality. With my current speaker and listener positioning, they produce rising output down to 45 Hz and produce usable but diminishing output down to around 30 Hz, as measured by the Omnimic system.
10. I do like the sonics and measured response of the Swarm system best so far using the 4th-order Butterworth low pass of the Lyngdorf. The 1st- and 2nd-order slopes affect the measured range above the crossover too much for my liking. The 8th-order L-R crossover sounds a bit "strange." I bypass the Dayton amp's analog crossover by feeding the analog line out of the Lyngdorf into the LFE inputs of the Dayton amps. That definitely makes the subs sound a bit cleaner than feeding the signal through the Dayton's analog low-pass filters. I have been adjusting the crossover frequency and slope using the Lyngdorf's digital controls.
11. I have been using the Dayton's analog gain control to adjust the overall level of the subwoofers. This is actually easier to adjust while watching the real-time Omnimic measurement display than is watching the display while changing the analog output level of the Lyngdorf.
12. I have not yet tried the Dayton amps' parametric notch filter to attack the primary bass resonance. In my room, the biggest resonance seems related to the floor-to-ceiling mode and is in the 70 Hz range. With my current speaker placement, however, this resonance is not very noticeable sonically and measurably.
13. I adjust the phase for quadrature using the phase control on the Dayton amps. There are many ways to do this, but works for this system is as simple as leaving the left channel amp phase control at zero degrees and setting the right channel amp phase control to 90 degrees.
14. In this system, in this room, with the Swarm set up as described, the response of the system measured with the Omnimic is basically a pretty flat line from 20 Hz up to the chosen crossover point. In my current arrangement, I have the crossover set at 45 Hz. In prior set-ups, I had it set as high as 60 Hz and as low as 40 Hz.
15. If I want a higher crossover from subs to Stirlings, I would high-pass the main speaker outputs from the Lyngdorf at a chosen frequency and low-pass the analog output of the Lyngdorf at that same frequency. That would be a way to erase some of the low-frequency room lift I'm getting right now since the lift is coming from the Stirling output into the room, not the Swarm output, which is basically a flat line as configured.
