Vibration/boomy bass and assorted uses for old mouse pads (1 Viewer)

[RobWil]

 

[Larry Talbot]

I wrote that add as a favor for you, Rob. You can use it if you want.

 

[RobWil]

Ohhh! Thanks , buddy! :b



Ahhh! I love a girl who keeps her amps in the basement!

 

[EricaC]

LOL, oh you guys.

Thanks for the kind comments. As to availability, guess you'll have to ask my boyfriend. who's also pleased to keep my amps in the basement.

Erica

 

[EricaC]

BTW, Rob, I didn't catch if your speakers are spiked? If not, I highly recommend spiking. Otherwise, your floor (a suspended design, if I read correctly) will indeed resonate and add a lot of bloom n' boom. If you're concerned about the wood floor, you can stick a piece of felt to a coin and then put that under each spike. I did this for my DBLs, which weigh about 200 lbs a piece and would have destroyed our hardwood floor.

Some people prefer mass loading with a concrete paving stone and spikes, but I've had varying success with those. A soft pad under a speaker is definitely a no-no, however, as it may cause the speaker to rock and 'smear' your high-end.

Hope that helps.

Erica
- who's spent waaaaay too much time fiddling with the stereo bits.

 

[Chu Gai]

Erica, where did you ever come up with this? Yes, self-inductance exists in a variety of electrical components and when wire is coiled, it does get substantially higher due to the coupling of the magnetic fields, etc. However for wire it can be calculated and is dependent upon the geometry of the wire (round, rectangular, square, oval, etc.). To put a face on this number for wire, according to National Wire & Cable, the self-inductance of a single wire is approximately 0.4 microhenries/foot. This is pretty much independent of the wire's diameter. In other words, this is such an inconsequentially teeny, tiny, small number that I don't think one could reliably measure any changes in that number due to vibrations. If the magnitude of the inductance is a non-factor and the change in that non-factor is an inconsequentail percentage change, then really, who cares? Another way to look at is is to take some device, let's say an amp and change one wire from 1/4" to 1", a fourfold increase in inductance in that part of the circuit. Now do you honestly think the pre and post modified amp would sound any different? I think not.

While poor speaker placement and poor room acoustics are indeed issues, they don't mask these effects because these effects are inaudible. One can always find a particular situation where a component such as a turntable or CD player is having difficulties due to highly specific and unusual circumstances of location and program source material that is frequently volume related. Solutions aren't all that difficult there and putting one's player on a speaker and finding it is having dropouts doesn't prove anything other than one is being rather foolish.

As far as high end electronics being ruthlessly revealing all I can say is that most high end designers have no access to the sort of sophisticated laboratories and testing facilities as 'mid-fi' companies. So they can't test for long-term reliability, propensity to misbehavior under certain speaker load conditions, etc. In fact, it can rather convincingly be argued that hi-end products (amps/preamps/players) have a very significant number of products that are most assuredly not deserving of the term accurate. Yes they can be ruthlessly revealing but that has more to do with incompetence than anything else. That's a designer that hasn't optimized their circuitry so that it sits on a wide global maximum and instead sits on a local spike. Any changes will affect it. This is something that's desireable? Still, there are fans of the ruthlessly revealing MG that leaked oil wherever it was parked.

Your products have feet on them for the same reason that many products that are electronic and not even in the audio field do and that's primarily to provide additional surface area for the dissipation of heat. Not having them would also make stacking a bit more difficult not to say of causing cosmetic damage to the touching components.

Even low end stuff, driven within it's design parameters will have more than sufficient transient response to accurately reproduce what's fed into it. As far as filtering goes, really now, what product has no filtering whatsoever? Got to have some so that you can take that AC and turn it into essentially ripple-free DC, no?

There's somebody making a product to meet anyone's idea of what they think the product should be resting on. Hard products, soft ones, sandwiches of the two. You name it, there's someone making something to indulge every whim that's out there. Proof though is largely relegated to testimonials and testimonials without a sound scientific basis to provide a framework for truth and justification don't mean much. We've got testimonials for aliens, Q-Ray, feng-shui, dowsing, and the list goes on.

I agree the best judge is your ears, however conducting an appropriate test is not something most people are interested in or inclined to do.

 

[RobWil]

As to availability, guess you'll have to ask my boyfriend. who's also pleased to keep my amps in the basement.

Arghhh!....the bum!
Sorry to hear about your availability as San Francisco is also my all-time favorite city! Spent many a day there when I shoulda been in school cross the bay! (Tennyson High, Hayward, Class of '71) Probbly too old for ya anyway. :frowning:

No, my speakers aren't spiked, although I am most often Ahhh!...love that good ole American microbrew!

They are Klipsch KG 5.2's if you're familiar....mid-fi at best but they definitely have their pluses. They have cheap ole rubber footies I'm afraid. However I have just placed them on some 14"x14" paving stones with some success. I originally put mousepad on each one but found , just as you stated, that it hindered rather than helped. I'm pretty happy right now and am convinced the paving stones and mousepads under the amps have helped considerably. These suckers actually put out some pretty good bass!
Thanks for your positive input and remember.....there's plenty worse things in this world to be fiddlin' with besides stereo bits!
Cheers! Rob

 

[RobWil]

Oh jeez....look who just piped in :rolleyes
Erica...meet Chu.
Chu,.....Erica.
Don't listen to him....he's from the wrong coast and has breathed too much carbon monoxide back there I'm afraid. :alien:

 

[Larry Talbot]

"Proof though is largely relegated to testimonials and testimonials without a sound scientific basis to provide a framework for truth and justification don't mean much. We've got testimonials for aliens, Q-Ray, feng-shui, dowsing, and the list goes on."


You tell 'em Chu. I'm glad you threw the aliens and the feng-shui in there, because the phenomenon you're talking about is indeed widespread, and hardly limited to the world of home theater...
My fiancee is a physicians assistant and people come into her office all the time swearing by this home remedy or that home remedy - blood of newt for acne, eye of toad for hearing loss, etc - most of which they got (surprise!) off the Internet.
When she explains that there is no evidence that this stuff does what people claim it does (and in some cases, there is evidence that it does NOT do what they claim it does) many of her patients still swear by it no matter what. It is the power of their own belief that sways them, nothing more.
An example from my own life: After reading about a tweak on the net I tried it out on my home theater system and was thrilled to hear a definite improvement in the sound. An obvious change for the better. It wasn't until I double checked my system that I realized I hadn't actually made the change I was supposed to, and that my system was thus set up EXACTLY the same as it had been before. The only improvement was entirely in my head. I didn't think something like this could happen to me, but it did.
I'll still try out tweaks, but I'm a lot more skeptical now. By the way, my fiancee, who is a SUPREME skeptic, particularly when it comes to my audio addiction, grudgingly admitted that my new acoustic panels HAD made a big difference in the sound of our theater. At the risk of repeating myself, if you have a bass problem, I suggest you look into that idea. If you're feeling real lazy, Jon Rich (I think that's how you spell his name) recommends buying fiberglass rolls and just leaving them in their plastic bags and sticking them in the front corners of your home theater as super simple bass traps. You might try that. If it doesn't make a positive change you could always take them back...

 

[EricaC]

RE: microhenries and metrics

What is smallness? What, ultimately, translates into a meaningful number for HUMAN HEARING? Did you know many of the capacitors in your stereo are measured in picofarads? That's one _trillionth_ of a farad (1x10E-12). Change the size by an order of magnitude or two and you still have a rilly rilly small number, but believe me, things will start to sound different. Did you know that the human nose can detect aromas in quatities of a few parts per trillion? Or that we can taste chemicals in dilution as low as 0.02 parts per billion [Schlosser]? That's like adding one drop to flavor _five_ average size swimming pools.

So, equating 'small number' to 'perceptibly insignificant' is just wrong. In other words, it ain't the size, but...oh you get my point.

What _is_ a meaningful assertion is that these effects/changes are inaudible. But I will have to respectfully disagree with you here. If you can't hear something, it only really means YOU can't hear something. Not all ears are created equal, and lacking any metric for quantifying our qualitative perception of music/sound, I guess we're left to discussing what people should or should not spend their money on. I'd prefer to bypass any lectures on double-blind testing and A/B tests and assume some objectivity in listening on both our parts.

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RE: incompetent designers and local maxima

Ok, I get your point, and also your very generous concession to varying tastes and 'whims'. But to deride a product (and its designer) simply because it fails to meet the widest possible mass-market 'global maximum' is simplistic and provincial. If someone feels justified in spending their money on a leaky MG because of whatever other value the MG brings, then I say let them and the marketplace is better for it. And it's certainly your perogative to judge the MG as crap because it won't share parts with your Chevy (see, I can play this game too).

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RE: testimonials and feng-shui

Let's not play the game of binary opposition, as it throws the baby out with the bath-water and gets us nowhere.

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Rob, sorry to have derailed your topic. Good luck with your system.

Erica

 

[Larry Talbot]

"I'd prefer to bypass any lectures on double-blind testing and A/B tests and assume some objectivity in listening on both our parts."

Never assume. That's what's so good about double-blind. You don't have to.

 

[EricaC]

No, really?

My point is merely to head off a discussion of much belabored topics like double-blind and A/B comparison tests. I wanted to assume that we already know the folly of placebo effects, secondary preference, and all that.

I'm as skeptical of tweakery as anyone, but I'm equally skeptical of wholesale dismissals of all optimizations simply because of the 'bad apples' out there. It's illogical.

I hope that we can elevate the level of debate beyond rote polarization and discuss the broad gray area inbetween. There's lots of interesting things to talk about, IMHO.

Erica

 

[Chu Gai]

There was a gentleman who once purchased a power cord and like all good men who purchase power cords and read audioasylum, no scratch that, absorb the wisdom that's contained in audioasylum, he developed the peculiar habit of nodding his head like a bobble-head doll on the dash of a car with defective shocks going down a length of railroad track. After all, this phenomenon of break-in had all the things going for it. It had scientific explanations (none ever confirmed). It had esteemed men, men of science and reputation, men respected in the audio industry, recounting their own observations. And of course it had himself. He had touched the wound. He had been to the mountain. He believed.

But how to break in this power cord? Such an expensive power cord needed significant time before the true sonic benefits of widened soundstage, improved musical presence and articulation, and increased dynamics would manisfest themselves. Knowing that he would be away for several days, he decided he would plug the cord into the wall outlet and let it 'cook'. Then we he returned he would listen once again because he knew that he could use his own highly developed sense of hearing and profound acoustic memory to accurately compare the sound before and after. Well after returning he promptly reported, on another forum however, the wondrous benefits of break-in. He was nodding his head faster than Divine Brown looking for something in Hugh Grant's lap. A few members of this forum pressed for more details. Well he finally said that since he didn't want to play his system while he wasn't around, he just simply plugged the cord into the outlet. Nothing was attached. Informed that unless a circuit was completed that it was impossible for electricity to flow in the power cord he came to the realization that nothing had been cooked. He had, after all, remembered something about basic electricity. The head stopped nodding and something wondrous happened. He started realizing just how easy it is to fool oneself. He realized that acoustic memory are not words etched in stone. That it is fleeting, variable, and highly dependent upon beliefs and external influences.


Actually Erica the nature of hearing is remarkably constant with people. Politely I will say that you're misinformed. Basic human auditory sensitivities have been measured world-round, in at least nearly every race, colour, or whatever distinction you want to make, and the basic sensitivites ARE THE SAME. There are no basic differences in hearing with the exception of people born with an impairment. Sensitivities change with age, exposure to auditory pollution, but they're the same. This is in quite the contrast to olfactory senses which have been proven to be especially variable.
I know what a picofarad is but that has nothing to do with your rather enormously speculative claim regarding self-inductances. Perhaps if your amps are that sensitive you need to stop thinking of them as being highly resolving and start thinking along the lines that they have an electrical problem that needs servicing.

It's rather remarkable, don't you think, that back in 1971, an atomic clock was flown on a jet plane around the world and its time compared to a synchronized clock before and after this trip. I guess the reason why the clock that was flown was a few billionths of a second slower had something to do with all those nasty inductances induced by vibrations from the jet and nothing to do with Einstein having been right about time slowing down as one speeds up, huh? Or our ears are more sensitive electronic measurements? A leap of faith often takes one down a rather steep fall. Better to just take the bridge.

This is not a question of personal preferences Erica. Designing a product such that it meets its specs over varying conditions is not 'designing for the masses'. It's sound engineering. It's quality.

 

[Doug Pyle]

Gee, and I just thought your CD player was rattling when the volume was up. Sure, the mousepad could help cushion that.






( )

 

[EricaC]

Designing a product such that it meets its specs over varying conditions is not 'designing for the masses'. It's sound engineering. It's quality.

Nice rhetoric, but again a simplistic and specious view of product design. As an engineer and scientist, I really have to take exception to this kind of blather.

Erica
-- you should really be sure you know how atomic clocks work, or are familiar with the concept of engineering tolerances, before you attempt that kind of trolling on the internet.

 

[Larry Talbot]

"What can be measured about hearing is not the same as what is perceived by human hearing. Try again."

Is this the "Golden Ears" theory? I've read claims that the hearing of a true audiophile is substantially different than that of a normal human being, though what exactly constitutes this difference is never precisely explained. Proponents also claim that this mystical difference can not be measured, which of course circumvents the thorny problem of trying to test it objectively. Hell, if it can't be measured, there's no point in worrying about it, right? Just shell out the $600 for Chu's power cord and enjoy the benefits

Your distinction between what can be measured and what can be percieved is important, since one can of course percieve a difference in sound, without actually HEARING one. You think you hear a difference, but you don't, the same way you might awaken from a dream believing someone has just called your name, when in fact no one has.

Does it matter if one "percieves" a difference, or actually hears a difference? If we are to assume that reality matters, I think the answer would have to be yes, it does. Otherwise we are living in the Audio Matrix.

But Erica, I think you made a more important point, in the context of this discussion, when you said:

"If someone feels justified in spending their money on a leaky MG because of whatever other value the MG brings, then I say let them and the marketplace is better for it."

IMO, the key word here is "feels." I'm sure you know that a major component of consumer culture is getting the consumer to feel a certain way about the product you want them to buy. What you are in effect doing is selling them this "feeling," which may not have anything to do with the actual quality of the product in question.

The marketplace, may be better for this, as you say, but I'm not so sure the individual consumer is.

 

[RobWil]

Rob, sorry to have derailed your topic. Good luck with your system.

No problem!...please , have at it! I seem to have a knack for starting controvery here

 

[Jim A. Banville]

Hey! I put rubber feet on the bottom of a flower arrangement we got for our glossy dining room table to keep it from scratching the table. Do you guy's think these feet might actually make the flowers look better too?! Woohoo! I've got to let the ladies down at Michael's know about this tweak!

 

[Jack Briggs]

Anybody here remember Enid Lumley, who used to write for The Abso!ute Sound back in the 1970s and '80s? Voodoo audio really seemed to come into its own when her articles were receiving the blessings of Harry Pearson. I keep thinking of those stories when I scan this thread.

Also, anyone ever hear of The Tice Digital Clock? I'll elaborate if someone confirms having heard of this device. Chu, did you ever read about it? You'd love it!

 

[Chu Gai]

I know a little about engineering and experimental design and statistical quality control and psychoacoustics and marketing psychology. I've also got a pretty good bull-sh*t meter that every now and then I need to double check for myself to determine what I'm hearing is real or just my imagination. Now you're the one who made the claim about the inductance of wires inside of components varying in response to external vibrations and you're the one saying that the inductance of a wire, no matter how short, is significant. Now either come up with some numbers as to the magnitude of the changes by either using equations for circuit design or point someone to a legitimate paper that discusses this. This is not a turntable, it's a CD or whatever player RobWil happens to have. Boominess can be looked upon as enhancement in the lower frequency regions such as from 60-80 Hz. As to how vibration can cause something like a 2-3 or more dB change in that specific area of the sound spectrum in a solid state CD player or for that matter amp or preamp is a leap even Evil Knievl wouldn't attempt. So, if you're going to make the claim then come up with the facts and not anecdotes. If you prefer to use controlled testing in your own individual work but eschew it's use when it comes to matters of audio that's your preference. Don't expect it to stand up without some scrutiny. What's next, the nature of the sound is affected by release of energy in speaker cables due capacitance effects?

As far as what's able to be perceived by people's hearing, did you think that perhaps this was determined by testing people? Things like auditory masking, the identification of equal loudness contours by Harvey Fletcher, and just noticeable differences came about from careful work (horror of horrors it even involved dbl blind work too) across a very broad spectrum of humanity. Consider the following work in a peer reviewed journal as to the sensitivity of human hearing: "Level Discrimination As a Function of Level for Tones from 0.25 to 16kHz" by M. Florentine, S. Buus and C.R. Mason, Journal of the Acoustical Society of America, Vol. 81 No. 5). While there is always a bit of spread in data, one can always err on the optimistic Stereophile side of things and choose the worse (best?) case scenario in attempt to make some hay.

There's not a room out there whose acoustics can't be substantially improved with a little bit of effort with regard to room treatments, speaker placement, and maybe some selective equalization to tame nasty peaks. There's no need to paint the areas where black and white exist with gray paint. I'll take that in my back pocket over a mouse pad any day.

I don't know about it making the flowers look good. The ones i order from deadflowers.com always look....dead.

Yes I've read about Tice's clock and maybe you can confirm for me that I've heard that Tice went belly-up. Well I'm sure another quack will rise to take his place. The carnival always manages to make the rounds.