Knowing how to build subwoofers is of course a completely different subject.
oldhvymec is right. Springs are of course the best thing to put your speakers on. All speakers, sub or otherwise.
Yes the springs do need to be matched or tuned to the load. Duh. Too soft and the spring will fully compress and cease to be a spring. Too stiff and it will not compress at all and once again cease to be a spring.
In between these two extremes, where the spring is matched to the load so that it compresses about half way under load, this is where the load becomes an independently suspended mass.
This is a range, just as it is a range for cars. People with actual experience tuning suspensions will know the idea the spring being a function of the cars weight are nuts. They will have a hard time explaining why a 1200 lb F1 car uses springs 5X as stiff as a 4000lb sedan.
In cars or audio tuning matters. Read mahgister, he has tuned his by adjusting the weight and noticed a change with as little as 1/4 lb.
Another factor is damping. Fine tuning weight matters a lot more with undamped springs because the adjustment is really resonance tuning. Damping controls resonance making this sort of tuning much less important. It still matters, but damped springs like Pods have a very wide range of outstanding performance compared to ordinary springs.
The moving mass of even a large woofer cone and coil is only some tens of grams. The mass of all the rest of the sub is some 30 to 40 kg or roughly ten thousand times as much. For sure some acoustic energy is lost on springs. For sure if you know Newton, f=ma, it is infinitesimally small.
Again, note the difference between those who have done and those who talk as if they have done. Would be nice if all the people repeating nonsense about springs would include a statement to the effect they do not really know what they are talking about, because they have not tried.
Go and try it. Then get back to us.
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A REL engineer told me that the only thing I might want to try is some BlueTak under each foot. But with or without the ’Tak, he said the sub will perform properly on my hardwood floors over a crawl space using the T5 as REL designed it. I tried the BluTak, and in my room, but while I could discern no dramatic differences, I left it on the sub feet because, well, it’s just sooo sticky. :)
I suspect that REL knows how to build subwoofers a heckuva lot better than I do. |
The last thing you want to do is put a subwoofer on springs. At some low frequency it will start shaking.
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WRONG... Just wrong..
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Giant generators are isolated from the concrete pad they sit to control vibration that turns into LF hum that can penetrate an entire building and make it impossible to work.
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I don’t know what constitutes "Giant" I’ve worked on Cats 1250kW mobile and stationary gen sets.
That same "Isolation Tech" Springs, Gummy Puffers and point of contact accumulators, keeps just about anything isolated, One from the Other.
12 to 15 tons of Generator can really put out LF harmonics. You couldn’t keep concrete UNDER it.
It would crumble it.. The engine perches would break, nothing would hold up. It has to be isolated.
They have used cancellation tech in machinery for a long time.. Joe Blow, human hearing application not so long.
30 years or so..
Regards |
Wow a lot of bad info here. Isolating things that move is important when you don't want to excite other elements of the listening room that add to and change the total sound you perceive. This is an issue of mass vs frequency. The total sound you perceive is the speaker direct sound + speaker indirect [reflected] sound + room dimensional sound + all vibrating materials in the room [tables, floors, walls etc]. Wooden speaker stands vs heavy Sound Anchor stands is clear evidence of this idea as the wooden stands will vibrate at an audible frequency (knock on them with your knuckles to hear an example) vs hi mass Sound Anchors which vibrate differently due to high mass. For the spring idea to work, it must be tuned for the weight of thing moving. Random springs set for an unknown weight will not solve your problem. Look at a car or truck, springs are set very specifically depending on weight and the many factors of behavior once excited. Decoupling sources of LF is important to not waste unwanted mechanical energy vs the energy you want: acoustic energy. Giant generators are isolated from the concrete pad they sit to control vibration that turns into LF hum that can penetrate an entire building and make it impossible to work. See Noisia Studio Tour | Razer Music - Bing videothis shows the springs used under some fairly heavy (150+ lbs) ATC monitors. Very specific spring rates. Brad |
Somewhere Richard Vandersteen posted an excellent article on speaker isolation and he makes a very good point I've made before:
You want to prevent the speaker's ability from moving back and forth. The forces of the drivers push against the cabinet and can cause it to move, which is audible even when there's very little of it.
So, I would stick to IsoAcoustic style of pucks for a subwoofer and nothing more springy.
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I agree...put a sub on springs is ridiculous at best.Maybe good if your trying to bounce around like a pogo stick. |
The last thing you want to do is put a subwoofer on springs. At some low frequency it will start shaking. Vibration/shaking in any speaker equals distortion. Just put your hand on the sub while playing an organ piece or better yet run a sine wave sweep and you can find all the resonance points. Keeping a subwoofer from shaking is not easy. Certainly, mass helps as does containment. In the home environment spiking it to a concrete floor would be best followed by spiking it to a wooden floor. The wooden floor's resonance point will hopefully and usually be above the subwoofer's range. Even so the floor is going to resonate regardless from airborne excitation. New designs Like Magico's big subs are using a method of force cancelation. They put drivers in opposite ends of the enclosure running in phase with each other thus their Newtonian forces cancel. This effectively stops the enclosure from shaking but does not stop cabinet resonances, another issue all together. Magico does it by building a battleship enclosure. |
Yes, so much better to avoid isolation. I mean, those subwoofers just don't seem as cool if they're not making my walls rattle, or vibrating things off shelves, or making the woofers pump on my speakers when I'm spinning vinyl on the turntable. |
Some folks like BASS exciters hooked to there seat. Maybe mattmiller is one of those. What ya think? REALLY likes to feel it.
TT guys tend to pay just a little more attention to vibration mattmiller "I Like the Feelin'", don't work to well.. Different approach.
Baffle widths, flat surfaces sharp corners, all take away from "Sound is Round" "Smooth" "Clear" "Fast".
EVERYTHING with uncontrolled vibration and every surface that collects it add to the issue. It's pretty weird when you get rid of it for the first time..
AND get to hear the difference.
It's also nice to have cabinets that sound like a fresh telephone pole when you knock on it. Curb and gutter type of quiet.
Regards |
The reason Matt says "tend" is because he doesn't know. If he did know then instead of pasting ad copy he would say springs and decoupling "are" better. Because he would know. From experience. https://systems.audiogon.com/systems/8367 Five subs. They have been on Cones, springs, and Pods. Springs are better than Cones. Pods are much better than springs. "A musical sound that works and enhances the main speakers, this will be lost if you isolate the sub" oh really? Read the listener comments. Please. |
You can't connect but you can Isolate it.. Always! Vibration in, Vibration out. Isolate from both, THEN remove as much as you can from the cabinets.. Speed the decay rates on everything.. No there's not 10,000 words.. My hands hurt.. :-)
Regards |
Dont elevate the sub, or De couple it from the floor as this will tend to make things sound dead, you will kill and rob the life out of the sub, this is a key quality that REL subs have. REL's not only produce bass they have a musical sound that works and enhances the main speakers, this will be lost if you isolate the sub from the floor, use bass traps or other resonance absorbing material in SPECIFIC areas to combat this.
Matt M
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Put it on springs. Much better. Nobsound springs if you can only afford $30, or if you want the best then Townshend Pods or Bars. Pods are virtually as good but cost less and I think look better, as in you hardly see them.
The curling stone is maximizing vibration feeding into the floor, walls, and ceiling. Vibrations travel through all these setting the whole room ringing. A lot of what you think is bass response or room acoustics is really the sub exciting the walls turning them into speakers muddying the bass and everything else. Travels into all your components distorting them as well.
Springs eliminate all that, allowing the speaker to radiate into the room sound waves not sound waves plus mechanical vibrations. The improvement in clarity is not subtle, not if you go Townshend anyway. But even Nobsound will be a big improvement from what you are doing now. |
