Roy Gregory Covers Another One of the Super Racks

[MylesBAstor]

[Johnny Vinyl]

If Roy gets paid by the word he just made a bundle to maybe even afford a downpayment on one of these racks. Haha! (Tongue-in-cheek - No disrespect intended).

I started to read, but it didn't hold my interest. In fairness, I'm also not in the financial bracket of being able to afford this indulgence.

[Per Sundell]

I think you are correct. Roy writes so long nowadays I get bored with him.
He has good ears. He makes good points. Bur he is not a good reviewer.

[kcin]

Wow, that's a tough read & I have and use some HRS goods.

[fcrowder]

You may want to look at the equipment rack reviews in High Fidelity.pl by Wojiech Pacula. He seems to have good ears and is willing to comapare one against the other.

[Johnny Vinyl]

Excuse me for my (perhaps) ignorance, but can someone explain "airborne vibration" to me. I'm having a difficult time getting my head around this.

[MylesBAstor]

You basically have three sources of bad vibrations: from the ground or stand (that picks up airborne vibrations) back into the equipment, created in the equipment say by transformers and created by the speakers. Whether or not airborne affects the equipment speeds on its resonant frequency. While amplitude counts, the response is a linear not threshold effect.

[astrotoy]

Excuse me for my (perhaps) ignorance, but can someone explain "airborne vibration" to me. I'm having a difficult time getting my head around this.

I always thought that airborne vibrations were things like loud music coming from your speakers which could cause equipment or even your room to vibrate. I'm thinking especially of very deep bass that can make your room shake. Larry

[Johnny Vinyl]

I always thought that airborne vibrations were things like loud music coming from your speakers which could cause equipment or even your room to vibrate. I'm thinking especially of very deep bass that can make your room shake. Larry

I rarely, if ever, play my music very loud...plus I'm not a heavy bass fan. I can see what you're saying as I kind of thought that, but maybe it simply doesn't apply to how I listen? So for me it might not be an issue or something I should consider as being important.

[Johnny Vinyl]

Additionally, and maybe this should have been the question. How does a rack fight this airborne vibration issue?

With respect, actually reading rack reviews can be educational.

[Joe Pittman]

Excuse me for my (perhaps) ignorance, but can someone explain "airborne vibration" to me. I'm having a difficult time getting my head around this.

Airborne vibrations are caused by soundwaves from your loudspeakers and reflected soundwaves from around your room that hit your equipment. These airborne vibrations when hitting components and especially turntables essentially create feedback. Think of ripples in a pond hitting an obstruction and causing it to move. This feedback is rather insidious because it is delayed in time from the initial sound from the loudspeakers delayed by the speed of sound in the air. The delayed vibration if not damped will tend to muddy the direct sound.

Ultra powerful bass drivers with very low frequency extension can have considerable feedback at low levels.

[Guest]

Allow me to quote from the introduction of one of my own rack reviews:

You don’t need to understand string theory to know that everything vibrates. Compression waves in the air vibrate eardrums causing tiny hairs in the inner ear to wiggle at specific frequencies, generating electrical signals into the brain where they turn into the perception of sound. When those vibrations organize in a felicitous way, we may hear music. If the music comes from our stereos, those same compression waves cause vibrations in the audio equipment producing them.

Music is good for your ears but bad for the gear that reproduces it. Musically induced vibration physically alters audio equipment. A vibrating printed circuit board flexes all its components to a degree. The result is audible signal distortion. For example, consider what happens if the music you’re playing matches the resonance frequency of a capacitor -- say, a nice V-Cap CuTF like the ones in my Atma-Sphere preamp. The physical oscillation of the Teflon causes small variances in the spatial relation of the capacitor’s copper plate that yield tiny yet measurable differences in its capacitance. A few microns of displacement can result in a small voltage deviation. Compound that effect across all the caps in your system and then amplify it and you have chaos.

Airborne energy does the majority of harm to signal accuracy, but it is not the sole source of problems. Structural elements in your home absorb and transmit energy to each other and anything in contact with them. Wood floors resonate and flex; massive, rigid concrete makes an excellent vibration transmitter. Not only is your system bombarded by air- and floor-borne energy, your components generate and propagate vibration as a byproduct of their own operation: power-supply transformers hum, digital transports whir, turntables turn. All of it contributes to that veil of distortion hanging between the listener and the music.

Audio equipment and audio racks don't know where the vibrations that impact them come from. Whether music is played loudly or in low frequency from bass drivers isn't really the issue. Part of the issue is the resonance frequency of materials, part is the ability of the rack to prevent energy from entering components, and part is offering means for energy within a component to mitigate or leave the component - that may include turning the vibration into another form of energy, such as heat.

Most audio racks meant to hold equipment aren't very good at vibration control. A rack needs to be designed for that purpose. It takes someone well versed in the physics of material vibration and energy transfer to make a rack that is effective in vibration control. Putting some cones on the rack's shelves or footers may have some marginal impact, but stretch in their claims at vibration control.

Fwiw I found RG's review very informative in its own thorough way.

[MylesBAstor]

I rarely, if ever, play my music very loud...plus I'm not a heavy bass fan. I can see what you're saying as I kind of thought that, but maybe it simply doesn't apply to how I listen? So for me it might not be an issue or something I should consider as being important.

You still have a tape deck? Record the music without the speakers on and then compare to normal playback, allowing for some loss from the recording process. Can tell you a lot about your isolation.