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Resonant energy transfer

Discussion in 'audio' started by John, Dec 28, 2021.

  1. DimitryZ

    DimitryZ pfm Member

    This seems like an ironclad proof to you?
     
  2. gustav_errata

    gustav_errata pfm Member

    I don't follow your logic.
     
  3. sq225917

    sq225917 Bit of this, bit of that

    There's a great video from HP showing how much vibration it takes to upset their measuring kit, think hammer action drill on the casework not being able to throw the scope off one iota. Solid state gear is pretty much all immune to less than superhuman amounts of vibration. Crystal oscillators and compact discs excepted.
     
    gustav_errata likes this.
  4. John

    John Rack’em Up!

    I sold a lot of Sound Organisation stands demoing how they improved the performance of Naim electronics so your welcome to believe what you will.
     
  5. John

    John Rack’em Up!

    Hi Fi supports always improved performance whether on concrete or wood floors based on my experience.
     
  6. h.g.

    h.g. Retired

    Indeed. It isn't rational but a form of reasoning will be taking place. Trying to work out what it is the challenging and fun part of the thread for some of us.
     
  7. JensenHealey

    JensenHealey pfm Member

    Unfortunately even DIYAudio seems to have more than its fair share of fake/ignorant (in the literal sense) scientists....
     
  8. DimitryZ

    DimitryZ pfm Member

    I think my experience has generally been positive with tube equipment, but generally no difference with solid state.

    This design offers the user a degree of "tunability." If one aligns the equipment spikes with foot spikes, the system should behave as a low frequency coupler to the floor with a bit of added mid-high frequencies (from music being played being picked up by the highly resonant sheet metal purposefully weakened by slits) injected into the chassis. If your equipment is microphonic, you may hear this as a dry bass and mildly elevated midrange and treble.

    If, on the other hand, the spikes are misaligned (in the plane of the sheet metal shelf), there should be some low frequency isolation and more mid range and treble injected into the chassis. This may be experienced as a more "tuneful" bass and a "live" mid and treble. The system may also seem louder, since the response will be trending toward a standard loudness curve. This may be perceived by listener as an "improvement."

    If one wants to see if their system "likes" an additional acoustic resonator exciting its' chassis, a thin aluminum sheet with upward and downward facing brass spikes (about $30) can be placed under your most microphonic piece equipment.

    The standard, practical approach to vibration isolation of microphonic equipment is actual isolation and damping. In our hobby, this is elastomer supports under the equipment. Chassis vibration is handled with added mass (brass pucks, loaded plastic discs, etc) or the use of mass loaded damper sheets or constrained layer foils (Isodamp company has many varieties). Tube dampers damp the glass envelope directly (I used to use Herbie's Audio products with success).
     
    gustav_errata likes this.
  9. sonddek

    sonddek Trade: SUPATRAC

    Turntables, valves, bad connections and CD transports can benefit from isolation as you would expect.

    I've never heard isolation of solid state equipment change the sound in a domestic audio environment, but it is easy to convince yourself or others that it does. I try to resort to blind tests when my experience is at odds with established theory, but I also try to check that the insertion of isolation equipment did not change other factors like wiring orientation and proximity to imperfectly-shielded power supplies. It might not be the rack itself, but the position. If it's to do with cabling and box proximity, then one would expect isolation equipment occasionally to make things worse.

    Each of us has incomplete understanding of the laws of physics, and they are also not complete per se, so a degree of humility with regard to expectations, and a willingness to blind test are my measures of practicality and sanity.

    The only isolation I bother with is semi-inflated tyre inner-tubes under my non-suspended turntables. I believe I can sometimes hear the effect in the tightening of bass notes at high listening levels. I don't use valves.
     
    sq225917 and gustav_errata like this.
  10. h.g.

    h.g. Retired

    Interesting. I would have expected reducing undesirable low frequency motions to show up as an increased clarity particularly in the midrange where we are most sensitive. Here is a note from just before the time pretty much everything to do with turntables went a bit silly. It is measurement focused (written in order to help support the sales of measurement equipment) but many of the main mechanisms are mentioned.
     
  11. awkwardbydesign

    awkwardbydesign Officially Awesome

    I've only just wandered into this thread, but if your stand vibrates, doesn't that mean it must be coupled to the cabinet? And as such can return the vibration to it?
     
    ff1d1l and gustav_errata like this.
  12. Jim Audiomisc

    Jim Audiomisc pfm Member

    For solid-state kit the only 'audible improvements' I've ever encountered is if the unit has an acoustic transformer buzz. For that some damping can help - on the unit and/or in its feet.

    Speaker cabinets or their sound injection into the flooring can affect the sound. But for that I've found that damping generally works. Using spikes on a wooden floor for something like the ESL63's or their children might alter the bass by using the flooring as a part of the speaker. But to me seem, er, pointless for conventional speakers.

    FWIW For a pair of LS3/5A's I use on stands, the speakers sit on carpet tile on top of the stands, and I use spikes under the stands because if they just sit on the floor-carpet they wobble about! i.e. for safety rather than 'sound'. I did fill the vertical pillars of the stands with sand because without that they rang like cowbells!

    I've continued for decades to use a turntable sitting on a 'Co-Op' Hi-Fi/TV stand that I bought 50 years ago when no-one really thought of such issues. Doesn't seem to have upset the results. OK, the turntable does have a coin under one foot to ensure it is level and doesn't wobble. I would have said 'rock' but then I don't play a lot of rock music anyway... :)

    Carpet tiles are cheap. And come in many colours and patterns.
     
  13. h.g.

    h.g. Retired

    I think you are assuming the thread to be a bit more rational than it is. What is being floated to see if it might be accepted by non-technical audiophiles seems to be more to do with equipment racks for things like solid state amplifiers rather than stands under speakers or shelving for turntables. Nothing is clear or specified though. In which case the forces driving the vibration are from the floor and the air.
     
  14. gustav_errata

    gustav_errata pfm Member

    Be careful. It might still be prone to boogie-ing.
     
  15. Jim Audiomisc

    Jim Audiomisc pfm Member

    Shure it will. :)
     
  16. chord

    chord pfm Member

    Please imagine:
    There are the stand + speaker and an air-cushion between them; I think you see that stand / speaker will be isolated quite well; speaker-resonances won't shake the stand; the 'all-system-resonances', (an amount of vibration) let be 100 units; cabinet will resonate 95 units; stand has 5 or so.
    If you use an ultra-light metal stand, I think the values can move around 35/65 or 45/55 stand/cabinet ratio, I do not know; maybe 25 only or less.
    The important thing is, that these 25 or 35 or 45 or any units are came from the all-system-resonance; it means that your cabinet will resonate less then previously with the air-cushions.
    Means, here the stand-vibration is the 'resonance-remover'.
    Simple physics.

    When you use a heavy stand, the situ is vica-versa; because the resonances delivered by the mass-ratio, stand won't be resonated so much, your cabinet will do it.
    And what about the singing stand? (my one sounds almost exact 'E' when fluffing with nail)
    These vibrations are not in direct contact with the drivers and after the transitions they will be 'out of tune' compared to the original cabinet-resonance so won't disturb the performance.

    Any contras?

    P.S.
    1. It's an extremly simplicied explanation.
    2. Of course, there are some more complicated situations. I mean the sand-filled metal stands where the resonance will be adsorbed by sand. But the mass-ratio in the 'resnance-removal' project will have the same importance.
     
    h.g. likes this.
  17. h.g.

    h.g. Retired

    Nailed it!

    BTW is anybody interested in the actual physics of stands under loudspeakers?
     
  18. Tony L

    Tony L Administrator

    I would be if there was any! It is one of those things that is so insignificant to the future of humanity no one funds any real research.

    PS From a subjective perspective I reside in the “audiophile stands do often make a difference, and usually for the worse” camp. I’ve certainly ended up no fan of spikes, cones, resonant metal frames, glass etc.
     
    tuga likes this.
  19. Ian G

    Ian G pfm Member

    Celebrating the end of the year I've enjoyed a couple of IPA's, however my wit's are still suitably functioning for me to believe the above post is totally pants.
     
    chris geary likes this.
  20. John

    John Rack’em Up!

    It’s interesting that the Star Sound products are so dismissed by our resident engineers who unless I’m mistaken have never heard any of their product offerings. There’s plenty of information on their website that explains what their stands do.

    A company that’s been around twenty plus years, sells over 500,000 units and offers a money back guarantee must me doing something right. There’s quite a few Mechanical, Material and Electrical engineers on their staff so it’s not just a marketing company.

    http://starsoundtechnologies.com/aboutUs.php
     

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