Who has done work on needle bar/diaphragm resonance and mass

[PeteLeoni]

I am a mixing and mastering engineer, I came to the hobby as a way to get away from "hearing shop" and just hear different music without all of the crap I need to think about on equipment. But I can't help it. As title. I have "discovered" some rather remarkable simple "fixes" so I just want to know who has done recent work on this?
Thanks!

[Lah Ca]

There is a CAPS member, Don Scheirer if memory serves, who done some experimental work with reproducers which he has discussed at meetings. He is a former radio/sound engineer and is quite knowledgeable in a high tech sort of way.

[PeteLeoni]

Thanks.
That's kinda what I am looking for. I found a ridiculously quick trick that was so obvious but performed a near miracle.
I have done work on acoustic guitar pickups, so I ported it over, but before I share I want to make sure I am not replowing tilled ground.

[JerryVan]

How about just telling what you have in mind? Even if it's been done before, it's possible that many of us may still not be aware of the improvement/modification.

[PeteLeoni]

Ok. I have a lot of different reproducer heads. All of them share one great fault. A distinct ringing at 750 to 1000 hz.
The truth is this is quite easy to damp using titanium dioxide (an inert substance btw) putty right in the center of the mica where the needle bar meets the diagram. I was able to tune it very quickly by the size of the ball. I could go into a lot of detail here but I won't for now. The truth is it depends on the reproducer and the resonate peak but it's going to be around an eight inch to quarter inch ball. The putty just sticks and stays and is simple to remove leaving nothing. This sold as caulk cord weather seal. It is exactly the right character for the job. It completely damps the resonance and besides lowering (obviously) the volume (how could it not) it leaves most of the rest of the frequencies alone. Bear in mind I am a life long mixing and mastering guy. I know what I am hearing! I was hoping to get some data for you before I posted this but it is what it is and it works! Use a heavy needle and you get everything back, flatter response no ringing. This is a winner imo. Especially on #2 which rings even worse than the rest, bit it most certainly works on Exhibition and #4a and Silvertone ...try it you have zero to lose and everything to gain. BTW it certainly does not inhibit the upper end only lowers the low end resonance and stops ringing cold. There it is and I am now ducking. It's OK I am used to it. (-:

[PeteLeoni]

By way of introduction here is a bit about me from Mix Magazine
Hoping you all won't find me a complete idiot.
I have done a hlot more semi- pioneering digital audio work, nothing but performance and recording my entire life.
The funny thing is I wanted to get away from the tech and just listen to the dang music without worrying about FR and distortion, but it (obvious resonance)bugged me to much!

Ghttps://www.mixonline.com/recording/pete-leonis ... abs-375193

[CarlosV]

That's an interesting exercise! I remember reading about this technique of loading the center of the diaphragm some time ago. Have you measured such resonance also in aluminum diaphragm soundboxes?

[PeteLeoni]

No I don't have a functional aluminum diaphragm yet, but I will. This is so damn elemental one has to wonder why Victor didn't so this? On the electric horn driver front Western Electric, (in the 30s) produced what is to this day one of the finest horn drivers ever made, the 555.
Of course that is much later and the Orthophonics are in that era. Patents have a lot to do with why things were done in certain ways. At any rate, there is no question at all that this trick is a fundamental improvement in audio quality. The answer may actually be that the extra loading may not be good for the records. I am testing that now. I will also add that electric records that are virtually unlistenable on the Exhibition or #2 sound (relatively) absolutely great with the added load on the center of the needle bar.
I am going to play the same record 100 times (with 100 needle changes of course) and we will see what happens. with and without the mass. I have 2 copies of the same record in similar shape.

[CarlosV]

This is so damn elemental one has to wonder why Victor didn't so this? On the electric horn driver front Western Electric, (in the 30s) produced what is to this day one of the finest horn drivers ever made, the 555.

My guess is that the main objective in the early years was to get a loud reproduction, and the spectral response was not a priority, as the acoustic technology did not record the sound accurately anyway (that besides limiting a lot of the spectrum, introduced resonances in the music, generated by the recording horns and heads) . Only later, with electrical recording and associated improvement in the technical quality of the recorded music, the fidelity of the reproduction became a selling factor, and then engineers put their heads to work in developing better soundboxes and horns. At that point in time, nobody would waste time in improving their obsolete acoustic machines, they would just dump them and buy the brand new state-of-the-art orthophonics and their counterparts.

[PeteLeoni]

I was thinking along those lines
Volume taking precedent. "Let's have a dance party and show off the newfangled talking machine" Maybe even outside where you would primarily want every last decibel. At any rate and especially for people with number 2 reproducers, it goes from basically unlistenable to "not too bad at all" in an instant and the distortion from electrically recorded discs vanishes. All for a trip to the hardware store for titanium dioxide putty you probably already have use for or will.