It was from the arm motor. I never noticed it until I got speakers that went a bit lower than ESL-57 or LS3/5A. I ended up giving the turntable away after I got my VPI. I'll bet there's still some around on Ebay...
As would likely be the case if you removed all the furniture and other stuff from the room.
se
The HiFiman has reduced that affect quit a bit... open back, a lot of damping material and who knows. Its a LOT less mushy/blurry sounding in the bass compared to most that use the cavity resonance to boost bass.
Show me the xDSL circuit and I'll go buy a Stax headphone. Thx-RNMarsh
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RnMarsh,
I don't see how opening the back affects the cavity side of the headphone except as regards reflected waves back through the diaphragm even if the rear chamber is damped? Unless the diaphragm was perforated how does it change the head side of the cavity resonance?
I don't see how opening the back affects the cavity side of the headphone except as regards reflected waves back through the diaphragm even if the rear chamber is damped? Unless the diaphragm was perforated how does it change the head side of the cavity resonance?
No, not at all, didn't even know that thread.
Just would make my next project a bit easier.
jan
The volume is the volume -- that doesnt change, of course. The affect of fully enclosing the diaphram does affect the bass and its damping. The same way as a sealed enclosure or a tuned port would. They have done a very good job of integrating all the factors with thier driver characteristics. And, I dont hear what is attributed to the cavity space as much as most others. Thx-RNMarsh
Hi John, under heavy speakers the resonance is at a few Hz.
Under equipment rack with shelves made of kitchen top stone similarly low resonance.
Works for me.
Dan.
Rides Like A Roller...
On smooth roads this behavior is of little consequence, indeed it floats and rides nicely.
Rough surfaces can induce a higher frequency resonance, but that is the unsprung mass resonating (think spring rate/tyre compliance) but still not a lot of transfer into the cabin of the car.
The front shocks on my car are rooted. Going over speed bumps or stabbing the brakes can indeed cause a slow oscillation of the body wrt the road.
On smooth roads this behavior is of little consequence, indeed it floats and rides nicely.
Rough surfaces can induce a higher frequency resonance, but that is the unsprung mass resonating (think spring rate/tyre compliance) but still not a lot of transfer into the cabin of the car.
My car has one spring only per valve....that was the case when I last rebuilt the head.
One can always play with resonance frequencies to move them to a region where they don't appear to cause a problem. However, I would always prefer to remove vibration from the equation entirely if I can: so for example, couple the speakers to as massive a mass as possible to lower the resonant frequency to irrelevance, like Blu-Tacking them to the top of a safe; or always use viscoelastic materials, to dissipate the energy as heat.
Frank
Frank
I've traded 32" of snow for 60 degrees and blue skys for two weeks, one of my guys might have the schematic back home. IIRC jcx did a bunch of xDSL/headphone circuits on one of the head-fi type forums.
So, for you, spending our time to give experienced advices and technical explanations in order to make people save their time and money and improve their audio system is giving a hard time ?
For me, the 'hard time' comes from people promoting smoke and fraudulent 1000$ parts chasing phantoms at the quantum level, asserting the utility of 'burning raw cables' or pretending that inverting their sens with an AC signal will have an influence.!!!!
You know ? Everything witch cannot be measured and is against all the known laws of physic or the most elementary logic.
Sorry, but your post was just provocative.
Nice here in California, also. Enjoy!
And, if you think of it when you return.... the xDSL/headphone circuit? Meanwhile, I'll hunt for it. Thx -Richard
Richard, what he means is the xDSL drivers often find their homes in headphone amps and the same chips used for xDSL are reborn under another name as headphone drivers. like the TPA6120A2
Audible effects of TT --
So that is what he was telling me 😎
Did someone say 'mechanical resonances'? See B & K's App Note: "Audible Effects of Mechanical Resonances in Turntables." (turntables/arms/cart). Paper was also presented at AES, N.Y. 1977.
-RNM
So that is what he was telling me 😎
Did someone say 'mechanical resonances'? See B & K's App Note: "Audible Effects of Mechanical Resonances in Turntables." (turntables/arms/cart). Paper was also presented at AES, N.Y. 1977.
-RNM
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yep 😉 i'm just pretty familiar with this crossover (TPA6120 vs THS6012) and already knew of the designs done by jcx and threads over at head-fi. the TPA isnt the only part, there is a few of the old natsemi DSL parts make nice headphone amps, the loads are pretty similar if you think about it. like the TPA they are often current feedback.
ps. dont be so tense Richard 😉
ps. dont be so tense Richard 😉
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