On the draining of resonance.....

Recently Art Dudley, a few issues back in a post I think called '3 rules' discussed resonance. He basically said draining efforts via spikes etc just makes the speaker front vibrate more. He said no spikes and use felt pads on everything. Check it out.

I think part of the reason some people say a 4" wood block sounds better than a 2" thick wood block is because the greater mass as a part of the equipment-spike-block system resists being affected by external vibration to a greater degree than the smaller mass block. Independent of any potential benefit imparted by greater mass/material as sink for internal vibration.

I have a rather unremarkable rack that I am working to improve rather than replace because of unique aesthetic match to the room. Ultimately I will migrate the turntable to the rack with a set up similar to what I have recommended above.

Good luck with your resonance and vibration control efforts.

KN, I'd like to think you could get off you hands and knees......If you had a solid stand for your turntable, you know there wouldn't be any vibrations coming up through the floor--only through the air. Question is, would the energy in the air cause vibration in a low stand. Probably, yes, depending on size of room, size of speakers and proximity, subwoofer or not, etc, but you could cancel that with a final isolation between turntable and stand. It may even sound better--you never know.

Basement. We had problems with unstable fill on the building site so our basement slab now sits on top of $26,000 worth of crushed rocks. My turntable sounds great. Highly recommended. LOL

kn

Ooops, I meant do NOT transmit very low vibration....

The real reason cement floors work well is they do transmit the very low frequency vibration such as that produced by the motion of the Earth's crust nearly as much as standard flooring. Cement does not bend nor exhibit the dreaded trampoline effect.

Yep the construction in most good quality newer homes is good when it comes to earthquake tolerance but bad when it comes to interacting with your hifi as well.

Long live Bedrock!

You have to isolate your speakers from interacting with teh floor otherwise to preserve detail and clarity. Like isolation pads used under a subwoofer (I place my floorstanders on Auralex Subdude isolation platforms) or monitor stands also designed specifically to isolate monitor speakers from what they stand on (I use Isoacoustics pro monitor stands ).

If you have your speakers sitting directly on most modern suspended plywood construction floors, you are doomed to mediocre sound until you get some form of isolation in place.

There's no arguing with bedrock. Yes, newer homes have engineered floor joists that flex quite a bit with foot traffic. KN, are you in the basement, or on a slab?

I realize my suggestion to put gear directly on a concrete floor is something of a side light given the original post, and could be perceived as contrary to my earlier advice, so let me praddle on a bit further.

The conditions that made me resort to the more heroic isolation and "draining" were I think more typical of what others face, a shelf system on a wooden floor supported by joists. Everything flexed, and flexed further with loud music playing. My experience was that the biggest difference was made with the large, heavy wooden board directly under the piece of equipment, I assume because it adds resting mass and absorbs both external and internally generated vibrations. The second biggest difference was derived from using small metal cones to connect the equipment to the board. I have not used large brass cones, which some swear by. Without the large wood, the cones can sound bright. With the wood underneath, the cones added clarity without brightness. Isolating the large wood from the underlying shelf with something pliable like sorbithane dots added value, but proportionally less than the wood and the cones.

So why does the concrete floor work so well with my turntable (well enough to put up with bending down to change records)? I do not think that much internally generated vibration is goining into the floor. I think the value added is that the floor imparts diminishingly low amounts of vibration back to the table at any volume level or external input short of an earthquake. Imagine a 300 ton turntable platform. This kind of stability works effectively in concert with the sprung platter and arm of the Thorens. I haven't tried this with my amp yet, but am convincing myself as I write this that I should.

kn

Tosta, no.
What I am saying that if it still worked and was all you still had today you should not be distressed about it.
Easier said than done, but that's the goal .

Ommmmmm. Of course you would ask me that! My wood blocks I was using on my old shelf (and when I say old, I mean like 175 years old!!) don't fit on my new shelf, so my turntable is sitting on the ground, which is OK, because the ground is a concrete slab over 300 tons (literally, don't ask) of crushed rock. My old Thorens TD150mkII sounds best in this configuration sitting directly on the floor on its little rubber feet. The bass is from middle earth somewhere. In my rather flexible old wardrobe, my CD player, table and amp all sounded better supported with cones on a large wooden slabs that were isolated from the actual shelf (purely home brew) as described above and in the images from Mapleshade. If you have a concrete basement floor resting on a large mass of rock, I might recommend trying your turntable or disk drive on their stock feet sitting right on the floor. I haven't tried my amp in this configuration. If/when I reconstitute old setup, will post photos.

JAfreeman,

Great post! I can relate to that.

To me, music is my spirituality--it amazes, humbles and uplifts me. The system is my altar, out of which all nourishment flows. To acquire better sound is to bring a deeper reverence. It is a material pursuit in the interest of a spiritual revelation. Joseph Campbell remarked that the great cathedrals were built to render an experience of God. When you walk in, you are removed from your domesticity toward a deeper meditation. Even your local church, with the high ceiling and pipe organ, is meant to render a sense of that. And when you walk out, you are back to the pedestrian concerns of survival, etc. The goal, as he said, is to retain some sense of that meditation that transcends the more mundane concerns of life. This would also be the Zen state of being.
Anyway, let's start a new church out of our hobby. Each of our homes will be a sanctuary--we will call it Audiology, and we can all get tax breaks on our houses. We will need a high priest--anyone?
I am serious on the first part, though--I have been through a religious conversion, only to return to music as my inspiration.

Not to open a can of worms, but one of my Yoga instructors often refers to Yoga as an antidote for "spiritually deprived Westerners".

It resonates with me when stated. Not all Westerners are spiritually deprived of course and all are free to seek it out but spirituality is not a core tenet of modern Western Culture by any stretch so one has to find ways to seek it out on their own. Audiophiles included I suppose. Is teh gear teh end in of itself or a means to teh end of enjoying music, which IS often a spiritually uplifting event.

Schubert, are you saying I should still be listening to my 1967 Magnavox all-in-one turntable/IA/speaker system?

In the Zen tradition wisdom resides in wanting what you do have and not wanting what you don't have.

KN, in the Socratic tradition, your wisdom lies in not having knowledge of even one thing going forth, only to emerge with truth. I like to think so, anyway. Having little electronic knowledge, my DIY efforts have centered on the areas of room acoustics, building cables and the isolation of gear. These are product categories open for development by anyone, and it's just plain fun to achieve improvements on your own, without succumbing to the purple prose reminiscent of the Old West's traveling medicine show, where no claim is too fantastic to believe. It also helps to acquire finer new and used gear, even at reasonable cost--then the real DIY fun comes through, as you well know. Do you have some links to pics of your isolation/system?
Regards, Joe

Cool, will be interested to see what you have come up with. I am big on home brew isolation solutions, and my opinions have been hard won! Lots of early attempts that were different sounding from stock, but not always better, as mentioned by someone earlier in the thread.

Tnanks, KN. Maple shade makes very nice looking stands and platforms, brass, etc. and look effective. Although I would not scrap my solid maple table/stands, the granite slabs I am using have turned out to be mostly a sonic bust. I now have prototype footers on the granite surface and under the ARC mono blocks, one footer under each of the seven rubber factory feet. I also have footers underneath the Wadia player's metal pucks that receive the factory points at each corner. My footers are my design, use two natural materials, and are still under development. So far, they have taken the massive granite slabs out of the chain of transmission, imparting a new plateau of clarity, so I know they are effective. I hope to release them to the audio community as a low-cost addition, to be used in conjunction with plinths, slabs, points, factory feet, etc. From the opinions here and industry approaches offered, a general isolation rule has emerged: At least two isolation methods using a variety of materials are necessary in an audio system.

Wierd. That was not the link I intended. Trying again. http://www.mapleshadestore.com/galleries.php

kn

Jafreeman, nice system! I would not recommend putting metal cones or spikes directly on a stone surface like the one depicted under your amp. In that case, the stock rubber feet would likely perform much better. My experience is that spikes or cones work much better in the conditions similar to those shown in these images, where they are used to couple gear to a large slab of wood, which is then in turn isolated from the room. http://www.mapleshadestore.com/galleries.php. YMMV.

kn

Nobody really knows why any particular type of footer will sound good with a particular piece of equipment.

Good point, Psag, although some intuition may just help predict an outcome, e.g., your mention of a rigid, metal coupling of a tube amp would not be my first idea for damping tubes against mechanical vibration. A metal footer may be an effective supplement to a more cushioning layer, but not as a primary connection in all cases. I feel it important to employ at least two approaches to isolate a piece, e.g. sheer mass and soft isolation, or point loading over a big footprint of another material. I am developing a material that will allow for this rule.

ARC uses soft footers under their Reference Series preamps and phonostages, I assume for good sonic reason. One theory I've heard is that a drain-type metal footer works against the virtues of tube sound (warmth, fullness, etc.).

Nobody really knows why any particular type of footer will sound good with a particular piece of equipment.

I use Mapleshade brass cones and wood under everything. I never liked the sound from real or composite granite. I was told the danger of rubber feet is that the vibrations cannot escape the component. Fortunately it's easy to try (except under heavy amp), and see which works best for you.

Thanks for taking the time, KN. It's not that I doubt resonance occurs or that it does not need treatment. I'm just trying to get my head around this draining concept underneath the chassis on "mass loaded" points. I do listen to a GNSC modded CDP, treated by Allison Dynamics--the name escapes me--he was a guy who was part of the process. The damping materials inside my unit are impressive, as is the heavy TEAC clamping system. I use the Wadia factory spikes, but also the pucks. No problem understanding that. I have also isolated my big ARC mono blocks, each with no fewer than seven rubber feet from the factory. I will not defeat those with metal spikes--better to supplement them. Your thought of rubber bouncing energy back into the chassis....you may get some pushback from makers of rubberized isolation products on that one. My isolation scheme involves at least wood and granite, which certainly needs treatment, as well--always a process. Granite looks good, adds mass, but also picks up energy in the room. Not to put too fine a point on it, but yes, I do acknowledge resonance

I don't think you should get hung up on the exact reason
something may sound better or worse. Putting some type of
aftermarket footer under a component may change the sound for
good or for bad and that's the only thing that matters.
Personally, I think too many people knee-jerk for aftermarket
footers and IMO, they're not always an improvement. In general,
they seem to clean up a muddy-sounding system, which is good -
IF your system is muddy. But it seems to me that the vast
majority of complaints around here are that their systems sound
lean, forward or harsh and I don't think that cones or isolators
are going to cure that.

I am not quite sure what your point is:-/ That 1. The idea of internally generated vibrations being materially harmful to sound reproduction is unsound, 2. Even if it is harmful, which you doubt, (see 1 above), there is nothing to be done about it, and 3. A little point is less useful than a big point. Or maybe all three?

As for verifying points one and two above, I suggest you try it with a piece of gear with moving parts, tubes or transformers and see if it helps. Start with something cheap like small hard wood blocks directly on your support shelf to replace your rubber coated stock feet, and if that helps, you can try more elaborate and expensive "solutions".

As for addressing point 3, I think a mechanical engineer could add value here, but here is a lay person's take. Let's say you have a 35lb tube amplifier with big transformers that generate some internal resonance you want to "get out of the chassis". Your options are the 4 x 50 mm diameter rubber coated feet resting on your glass, wood or MDF shelf versus 4 x 1 mm points sunk slightly into a 4" thick hard wood slab (the same general size as you gear chassis or bigger, not to be confused with the small wood blocks described earlier). In the first case, the feet may slide slightly on the surface, reducing the transfer of energy to the shelf, and more likely, the rubber will act as a spring to some degree, storing and releasing energy back to the chassis, smearing over time any residual effect of the internal vibrations. In the second case, assuming a solid connection between the chassis and the body of the point, energy in the form of vibration from the chassis is transferred directly and effiently to the underlying wood slab, which then dissipates that energy as heat between and among the matrix of it's fibers. External vibration from the room can be minimized by isolating your shelf and or the wood slab with some kind of soft material that reduces effective transfer of vibrations to the wood and the chassis of your gear.

Ultimately, this is all just a bunch of words. You can continue to try to make some points, or you can just try points to see if they make a difference. Up to you.

Sure, resonant vibrations do occur--damping materials on interior walls, heavy transports, platters--all doing their job at the source. it's these claims of draining vibrations out from the top and killing them from the bottom, and it all takes place at the end of a cone, on a 1 mm round point. Yes, this is effective for mechanical vibrations in the rack, etc, but it seems to be asking a lot of that little point, or saying a lot, e.g., "We're gonna get 'em comin' and goin', yep you can count on it." Vibrations, that is, or perhaps customers.......

Draining vibrations for all many of things has been around for a long, long time.
Vibrations oscillate or reciprocate and can build up to be more of a mess if left unattended. Minute they can be and limited in scope and effect, but in the end it can be heard.

All the best,
Nonoise

I think the idea here is to remove excess or spurious energy from your system so it doesn't interfere with the good vibrations:-/ Whether it is internally or externally generated, resonance isn't an instantaneous or infinitely singular event that "happens" and then it's over, rather it involves vibrations or resonant movement within a system that usually decays over time. Draining unwanted or spurious "resonance" away from an audio component to an adjacent structure were it can be absorbed or dissipated as heat is a legitimate concept, at least in theory, to limit vibrations to those related to the relevant musical content, and not the frequency of your motor, transformer, etc. Try it for yourself, you might like the results.

kn

don't pay attention to the man behind the curtain Dorothy!...;-0