No, I mean physically raised, lowered and rotated. Output level, xover Freq, phase, etc. are more common adjustments but of course necessary for proper integration.
Genesis Advanced Technologies SuperSub Subwoofer
- Thread starter Ron Resnick
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I thought so. Did you notice any correlation between room modes (esp. the floor to ceiling dimension) and height of sub from the floor (or ceiling)?
This is a bit off topic, but relates to my queries about the SuperSub short stature.
What can we can learn fir instance from the SuperSub that can be applied to sub placement, integration etc more generally?
Well, to be fair, I didn't experiment with subs over ~40", however from what I've read and heard clearly there are benefits from loading a room from a tower of subs firing from, let's say 18" to 84". In general you're covering a wider swath of the room in the 3rd dimension (height) that few people even consider with subs. To your point, it would be interesting to know if Gary investigated elongating or doubling the drivers per sub to fire from the top half of the room rather than just the bottom half of space.
And to answer your question, what I found was - there was, in general more adjustability in sub integration when raising the subs, especially once over 12" off the floor. Also, the bass is cleaner and tighter once raised.
Thanks. I have stereo JL e112s. I raised them about 20" from the floor, that dimension is just because that is what I had to put then on. Just that was an impressive improvement. With this new basis, I am tinkering with placement again. Then room correction.
So far, raising the subs and esoecially improving my digital source (via considerable ethernet upgrades) have been a relevation in bass reproduction.
So now I am reviewing placement and room acoustics.
$100k sub towers are well out of my reach, but stacking is possible, such as REL 6 pack line array idea, but it doesnt have to be REL. Maybe just 4 cleverly placed subs will achieve a lot with less expense.
Here's some if thinking as food for thought.
What would be best arrangements ... line array off the floor, or distributed around the room as often suggested by user manuals (eg in corners, or middle of each opposing walls). They talk about smooth bass response, but from what listening position - more than one, or just a single sweetspot?
To my mind, locating subs away from nodes of room modes makes sense. That is not at floor level, ceiling level, or half way between these extremes.
Although, maybe it doesnt matter if there are drivers at those nodes that are producing frequency other than that of the mode of the floor to ceiling dimension. For instance, if the mode is 65Hz, a sub at floor level could produce say 20 - 55Hz (to avoid 65Hz energy), and a sub on top of that could produce 55 - 90Hz.
Otherwise 2 subs each channel producing say 20 - 90 Hz could be stacked but on a stand at say 15" off the floor. Maybe that would be better still?
Taking this logic a step further, combine the above where the sub at floor level is 20 - 55Hz and 2 more stacked on it doing 55 - 90Hz. In this case, perhaps a 15" driver would be better for 20 - 55Hz and small drivers on top for 55Hz upwards.
This approach could be modular rather than a single piece with a larger price tag.
Following that logic one might end up with an arrangement similar to SuperSub but less squat.
Hence my queries why SuperSub is not 2 or 3 way, and why squat rather than tower?
I hope this has some sense rather than the ramblings of a madman.
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garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
I explained why the SuperSub is not 2 way or 3 way and why it is shaped the way it is shaped in my posts earlier.
Even the 7-foot tall woofer tower of the Genesis Prime needs to be seen as a point source and not a line source due to the frequencies involved. At 32Hz (frequency of the lowest open string on a double bass) is about 10m.
Even the 7-foot tall woofer tower of the Genesis Prime needs to be seen as a point source and not a line source due to the frequencies involved. At 32Hz (frequency of the lowest open string on a double bass) is about 10m.
garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
Yes - raising the sub off the floor definitely works. One experiment I have done is to use the Prime woofer towers, and listening to pairs of woofers instead of powering them all up. A pair has 24 12-inch woofers with the top pair 6 feet off the ground. Some time ago, we had an interesting discussion here about a "swarm" of subwoofers distributed in 3 dimensions around the room. See if you can find that thread.
This is a huge topic and I don't consider myself an expert, but I do have quite a lot of amateur experience and have helped set up and install subs in about a dozen rooms over the past 8 years or so.
That said, my experience and what I've read and learned has taught me that
1) Optimal low frequency speaker / sub placement is often rarely near where the main speakers are placed. In fact, if frequencies overlap from mains to subs, issues are usually exacerbated.
2) While the human auditory system can't localize frequencies <=80Hz we can feel pressure - waves of low frequency energy and subs placed in proximity to the main speakers can yield more pleasing and some might say more realistic music reproduction including stereo (or beyond) ambiance. However IME there is often a tradeoff unless mains woofers and sub towers do not reproduce overlapping frequencies.
3) More subs are better but result in a diminishing return, most certainly >2 (again IMO)
4) Sub(s) output capability need to be capable enough to combat (for lack of a better descriptor) mains' woofers' resulting nulls and peaks. For example - a single 8" sub will have minimal effect in curving bass issues if your mains are Wilson XLFs but a pair of JLA Gothams placed appropriately will.
I believe the ideal and most realistic sub / bass is a combination of both bass / sub towers at close proximity to the main speakers augmented by several highly capable subs placed strategically in the room to smooth nulls and peaks. The best location in the modest - sized rooms that I incorporated subs in flanked the sweet spot left and right walls and almost never against the front wall L and R corners where they are commonly placed. The few rooms I've heard good sub integration at front wall positions were always in quite large rooms.
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Thanks for your reply Gary, I appreciate your time. The info provided about the SuperSubs is a bit dispersed so I have put the pieces of the puzzle here ...
I like using exactly two, and horizontally opposed so that the cabinet doesn't hop around when driven hard.
As the woofers are horizontally opposed, the cabinet hardly vibrates. Any vibration is generated from the internal air pressure in the cavity.
I found that if you have a low-pass filter that is greater than 18dB/octave there will be absolutely zero difference sonically facing side-to-side or front-to-back.
Even the 7-ft tall woofer towers in the Prime act as a point source.
With servo-control of the woofer cone (and sufficient power for the servo-loop), I couldn't measure any difference between 8-inch, 10-inch or 12-inch woofers. But they all sound different when presented with music.
However, during my experiments, I found that with exactly the same cone surface area, and the same excursion, 8/12/15 inch cones all sound different. Or feel different. Hence, in the SuperSub I used all three sizes.
I find more of a "gap" in the sound between my 48-inch ribbon midrange and a 12-inch woofer than I do between the ribbon and 8-inch.
Large woofers are better for the hall/ambience effect but they are harder to integrate to the midrange.
The SuperSub added detail and resolution to the bass in addition to the "holodeck" effect.
From the opening post too
In Gary's words: “It’s not a 3-way crossover, it’s not that that 15s get the lowest frequency. Instead – I managed to integrate all of this to make each of the drivers (15,12,8) move the same amount of air. The excursion is proportional to the area of the cone.
And other posts
SuperSub (optional): H 41” x W 26” x D 38”
From Part Time Audiophile item
His goal was to bring together the qualities that he loved in the larger 12? bass driver coupled with the speed provided by smaller 8? drivers.
Please correct me if I am wrong:
I think what you are saying is you didn't do 2 or 3 way crossover because you liked the different sound each size driver provides and you managed to get the 3 different sized drivers to perform harmoniously without crossovers.
And I'll read between the lines that additional crossovers add complications and layers to overcome.
And I gather what you are saying is that the layout of the drivers is to enable a point source quality (ie. shortish format rather than tall linear). Of course at 41' high it is still tall compared to most sub woofers.
The SuperSubs have the 8" and 12" drivers more than 15" off the floor, but the 15" driver essentially at floor level. Did you try lifting the whole thing off the floor to raise the level of the 15'" drivers also?
What did you observe from your experiments listening to just pairs of woofers in the Prime woofer towers? Did any pairs sound better than the others? Does this translate to typical ceiling heights of 8-9' (rather than a warehouse/workshop like in the photos)?
How did you ensure each driver moves the exact same amount of air? Reduce the outputs of the 12 and 15 inch drivers to match the 8 inch in terms of air movement? Surely the 8" drivers roll off at a higher frequency than the 15" driver and their cone area can't be the same.
I am one curious dude, hey?
Yes sub placement is counter intuitive. That may be a good thing. You may end up with long cable runs, You can get flat cable and run it under the rug. They also sell "cable covers. Ugly but they prevent tripping. Available at your home improvement store or office supply store.
garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
I will say this - I can tell you what I do. How I do it is my proprietary implementation, and you'll have to buy that. I have seen how some of my thoughts have appeared in products from my competitors. And I am happy for that as it expands and improves what is available to the market.
garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
With the vast majority of subwoofers being self-powered, using flat, long cable runs under the rug is the best implementation. Since they are self-powered, the input (even if it is a pair of binding posts) are usually buffered. Which means that there is a constant input impedance (if the buffer is properly implemented) and (even when very long) flat Ethernet cables are the best solution. Do not use fat speaker cables for your subwoofers. They are ugly, may trip you up, and likely to be much more expensive. You can buy 100ft of CAT6 flat cables for less than $20.
I respect that Gary, so I understand my last question was asking for some of your intellectual property. Although, I was just interested from a basic conceptual perspective, not the secret derails of your implementation.
However, the 2 other questions are asking for your observatiins from experiments, so perhaps you dont mind sharing those to help fellow music lovers.
I guess what I am wishing to understand is ...
If a sub driver also at floor level is beneficial when it is complimenting woofer/subwoofer drivers located some distance from the floor level.
And
If you observed an optimal/preferable height off the floor to locate woofer or sub woofers drivers.
Hence my questions ...
We all try different things, and when we share the experience it helps people narrow down what is worth trying themselves, and what is not. Especially when it comes to lugging heavy boxes around and up and down, and across rooms ... tethered to power and signal cables, and possibly stands.
Do you mean for line level analog signals from pre amps? I dont know of any subs that accept ethernet data input, even though some active speakers do.
Puzzling though, I have experienced significant differences in sound quality between ethernet cables used to carry Ethernet data (and the hitch-hiking noise) from server to endpoint. But that is another story full of mysteries and miracles.
Cheers
garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
Due to the wavelengths involved - you would have to get quite far off the floor for sub-woofers. With my speakers, they are not sub-woofers but they are woofers, so it does make a difference. There is NO optimal height since music is composed of many frequencies and proximity reinforcement would depend on the wavelength.
However, a woofer or sub sitting on the floor would excite more nodes/modes in the room than a sub at a height which would make it a point source at higher frequencies and not at lower frequencies.
Yes. Line-level bass input for the sub-woofer.
Note for "flat" surfaces (floor and ceiling) there is a null half-way between the floor and ceiling. Placing a sub at that point (height) can help compensate that null, assuming it is within the sub's frequency range (depends upon your room's height and frequency range of the sub). Of course, that usually only matters if you are also sitting at that height...
As Gary's post suggests, given the wavelengths, most find raising the sub a foot or two can make a difference by reducing floor proximity effects in the upper range of the sub(woofer).
FWIWFM - Don
As Gary's post suggests, given the wavelengths, most find raising the sub a foot or two can make a difference by reducing floor proximity effects in the upper range of the sub(woofer).
FWIWFM - Don
Thanks Gary and Don.
Reading between the lines, I gather Gary is saying that no pair of drivers in the Prime towers (when used without the other drivers operating) provided an optimal sound quality, weather they were the oair at floor level or higher up. I suspect each pair had pros and cons.
So maybe it is advantageous to locate the drivers off the floor so they are not a point source at floor level for higher frequencies.
I have experienced this ...
Lets apply this to a real situation, say a 9 foot floor the ceiling distance with a flat floor and ceiling - seems pretty common and what I have.
By ear and twiddling with roon paranetric eq I discovered a mode of about 65Hz. That conicides with the wavelength vut I didnt realise that at the time.
I compensated by implementing a sharp and deep cut in eq at about 65Hz. Energy was reduced a lot, higher frequency bass sounded much better, as did midrange. It seems thus is quiie predictable to these that know these things - I didnt.
Then I raised the drivers (JL e112 stereo pair, no room correction) about 2 feet from the floor. Much better again. These drivers are producing 20Hz - 130Hz and the mains 130Hz upwards.
2 feet happens to be about the anti nodes.
Overall, this is vastly better than no eq and subs on the floor. The pair of e112s presurises my room easily, even way down low.
My niggle is the upper bass (have not worked out freq) has a bit too much energy/slam probably due to 12 inches of high excursion driver, and I suspect crossing over lower to the 7 inch driver in my mains will be more suitable. My mains are TAD ME 1 which wuth SAM in my Devialet Pro can give 4mm excursion, carefully managed by SAM, probably more than adequate for say 80Hz up to the crossover at 330Hz.
Oh and the subs are now competing with the mains for the optimal location from floor and walls.
I suspect placing the subs at 4.5 feet off the floor at the node of 65Hz might not be good, even if it were practical.
Where it could get interesting is to stack a pair of subs each channel.
One approach would be 2 way, with the subs on the floor doing 20-50Hz, and subs on those 50-80Hz. Thus the sub on the floor not producing 65Hz so not impacted by or affecting that mode.
Another approach is each pair 20-80Hz, but located say 2-4 feet from the floor.
Its interesting that REL dont do 2 or 3 way with their sub arrays. Or mix driver sizes.
So, how does your experience and expertise shed light on these possibilities?
My hunch is the 2nd approach would be better bang for buck overall - bass resolution, delicacy, ease, as well as influence on higher frequencies . Then it is a question if each pair would have 2 drivers the same, or perhaps instead 1 x 10 inch and 1 x 12 inch, or 8 inch and 12 inch, using same JL drivers and amps to get a close match of performance.
Gary, what is the crossover freq from mains to SuperSubs? And Prime towers?
Cheers
Reading between the lines, I gather Gary is saying that no pair of drivers in the Prime towers (when used without the other drivers operating) provided an optimal sound quality, weather they were the oair at floor level or higher up. I suspect each pair had pros and cons.
So maybe it is advantageous to locate the drivers off the floor so they are not a point source at floor level for higher frequencies.
I have experienced this ...
However, I have been led to understand that the node is the place of greatest pressure and therefore is better to avoid placing drivers producing the frequency of that wavelength at the node. Such as described here ...
Lets apply this to a real situation, say a 9 foot floor the ceiling distance with a flat floor and ceiling - seems pretty common and what I have.
By ear and twiddling with roon paranetric eq I discovered a mode of about 65Hz. That conicides with the wavelength vut I didnt realise that at the time.
I compensated by implementing a sharp and deep cut in eq at about 65Hz. Energy was reduced a lot, higher frequency bass sounded much better, as did midrange. It seems thus is quiie predictable to these that know these things - I didnt.
Then I raised the drivers (JL e112 stereo pair, no room correction) about 2 feet from the floor. Much better again. These drivers are producing 20Hz - 130Hz and the mains 130Hz upwards.
2 feet happens to be about the anti nodes.
Overall, this is vastly better than no eq and subs on the floor. The pair of e112s presurises my room easily, even way down low.
My niggle is the upper bass (have not worked out freq) has a bit too much energy/slam probably due to 12 inches of high excursion driver, and I suspect crossing over lower to the 7 inch driver in my mains will be more suitable. My mains are TAD ME 1 which wuth SAM in my Devialet Pro can give 4mm excursion, carefully managed by SAM, probably more than adequate for say 80Hz up to the crossover at 330Hz.
Oh and the subs are now competing with the mains for the optimal location from floor and walls.
I suspect placing the subs at 4.5 feet off the floor at the node of 65Hz might not be good, even if it were practical.
Where it could get interesting is to stack a pair of subs each channel.
One approach would be 2 way, with the subs on the floor doing 20-50Hz, and subs on those 50-80Hz. Thus the sub on the floor not producing 65Hz so not impacted by or affecting that mode.
Another approach is each pair 20-80Hz, but located say 2-4 feet from the floor.
Its interesting that REL dont do 2 or 3 way with their sub arrays. Or mix driver sizes.
So, how does your experience and expertise shed light on these possibilities?
My hunch is the 2nd approach would be better bang for buck overall - bass resolution, delicacy, ease, as well as influence on higher frequencies . Then it is a question if each pair would have 2 drivers the same, or perhaps instead 1 x 10 inch and 1 x 12 inch, or 8 inch and 12 inch, using same JL drivers and amps to get a close match of performance.
Gary, what is the crossover freq from mains to SuperSubs? And Prime towers?
Cheers
A null occurs when direct and reflected waves are out of phase and cancel. Sticking a driver at that point basically "overcomes" the null. I am doing that in my room so can verify empirically that it works (if the work of Welti and others isn't enough). The only other practical solution for a bass null is to move the listening position out of the null. Treatment works but it takes either a lot of absorption, very large diffusors, or specialized tuned resonators.
I just re-read this thread, made extremely interesting by Gary’s gracious and extensive participation. This thread’s discussion of large drivers, I suspect, helped drive (pun intended) Lloyd to the dual 18 inch concept by Nathan Funk.
Also, Gary’s discussion and experiments support the notion that adding big subwoofers to my 8 x 8” woofer columns for ambience is not a crazy idea.
Lloyd and I both would want the subwoofer to low-pass below the 80Hz crossover in Gary’s system, so I don’t think the SuperSub works for either of us.
Lloyd: How do we figure out which would be better for our common 10Hz to 30Hz ambience objective, the wood cabinet Funk Audio 2 X 18” or the heroically inert Goebel Sovereign 1 X 18”?
Also, Gary’s discussion and experiments support the notion that adding big subwoofers to my 8 x 8” woofer columns for ambience is not a crazy idea.
Lloyd and I both would want the subwoofer to low-pass below the 80Hz crossover in Gary’s system, so I don’t think the SuperSub works for either of us.
Lloyd: How do we figure out which would be better for our common 10Hz to 30Hz ambience objective, the wood cabinet Funk Audio 2 X 18” or the heroically inert Goebel Sovereign 1 X 18”?
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garylkoh
WBF Technical Expert (Speakers & Audio Equipment)
If you are looking to add ambience to your Pendragons (specifically below 40Hz), then you are correct that 15" or larger subwoofers would be key. My SuperSub would definitely NOT work.
However, by the time that you get to 15" or 18" cones, in order to be sufficiently stiff, they would pose significant mass. Even the airmass contained in the stroke of the cone is not trivial. To overcome the inertia and momentum of this mass, servo-control is probably mandatory. In order to manage the vibration generated by this mass, you would (should) utilize two horizontally opposed drivers. There's your requirements.
The only product I've found that ticks all the boxes is the Rythmik Audio 18". You may have to build your own box and design a brace system that will not allow the box to hop around. With two 18" drivers, you need enough cavity volume, damping, and probably 2" HDF for cabinet sides. Even better would be a carbon-fiber composite sandwich for cabinet.
However, by the time that you get to 15" or 18" cones, in order to be sufficiently stiff, they would pose significant mass. Even the airmass contained in the stroke of the cone is not trivial. To overcome the inertia and momentum of this mass, servo-control is probably mandatory. In order to manage the vibration generated by this mass, you would (should) utilize two horizontally opposed drivers. There's your requirements.
The only product I've found that ticks all the boxes is the Rythmik Audio 18". You may have to build your own box and design a brace system that will not allow the box to hop around. With two 18" drivers, you need enough cavity volume, damping, and probably 2" HDF for cabinet sides. Even better would be a carbon-fiber composite sandwich for cabinet.
Thank you very much, Gary! Lloyd and I are looking at Nathan Funk's dual-opposed 18" drivers subwoofer. It is not servo-controlled, however.
I like the height of stacked 18" drivers. But a box with two pairs of dual-opposed 18" drivers . . . would be quite a box.
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