Sibilance and counterweight/tonearm decoupling

[flavio81]

I have used AT-OC9MLii and AT33PTGii (both microline) and never hear any disturbing sibilance with my SME V. Here with Wallys Fulcrum for Azimuth adjustment

SME V is a top, top, top tonearm. I wouldn't expect any sibilance problem with it too. I also can't remember any sibilance problem with my SME III. I also have not had any sibilance problem with my humble Rega RB303 tonearm either. In fact i have not had sibilance problems in a looong time, until I purchased this SME 3009 II, which, as the post mentions, had some problems.

 

[Mr Boochie]

link

Warning: The youtube presentator is insufferable.

Thanks for the warning. I'll wear an N95 facemask while viewing.

EDIT: Okay, I watched it. Ian is kind of famous among Net audio folks. I'm glad you brought up some criticism. I thought he sometimes cleverly forces his opinions onto the viewer --- to make the viewer feel that he came to a conclusion on his own. Ian is more entertaining than many Hi-Fi Youtubers, who are downright curmudgeons.

Let's just say Ian uses a small ball peen hammer to convince, while others use a sledgehammer.

Sometimes, it's hard to hear the audio differences between products in videos. Videos can lack the emotional connection of being there, which is hard for the producer to incorporate into his video. Emotional acceptance plays a big part in whether you like something or not.

 

[flavio81]

Not just Michell, but just about every other aftermarket provider extant. At most it's metal on metal; at least it's a hard plastic like nylon, teflon or acetal.... similar to the mod made to your SME. None that I'm aware of retain the soft compliance of the original....

This also means they're easier and cheaper to make, just simple metal on metal that can be produced by programming the CNC machine and just polishing out the finishing parts.

they can't all be wrong.

Most likely they all want to make a easy-to-make, cheap-to-produce product.

What i listen for is details in the background instruments where the harmonies and rhythm play against the melody. I like punch, too, but not in violins or saxophones where the sound can become strident.

Agree.

As to why the modification works with Rega arms I'm not sure, but I have a feeling it has to do with what Korf describes a headshell resonances. These not only result in frequency domain peaks but smear the time domain resolution that reveals tiny dynamics....and big ones like punch.

We're assuming the modification works. I would like perhaps more evidence, even if it's anecdotal.

Btw, if you want to explore a mod to remedy the shell resonance check out the thread below that decribes it in detail: It is fairly cheap, accessible and fully reversible, and will give you an idea of what the CW mod can bring to the sound.

https://www.canuckaudiomart.com/forum/viewtopic.php?f=32&t=42239

Yes, I saw your post years ago. It is a clever idea.

 

[flavio81]

Re ringing in Technics arms, the besr mod you can do to one is rewire it and add an internal rubber tube (Kab sells them for 5 bucks).

Yep. Some tonearms also come internally filled from the factory. For example many of the SME 3009 tonearms use internal balsa wood for damping.

Some of the improved Rega tonearms, sold under other brands, are foam-filled on the inside (i wanna try this mod someday).

 

[flavio81]

Maybe not on the same level as the tonearms here, but I use a Project 8.6" arm on my hybrid direct drive turntable. When I rebuilt the arm (straight aluminium arm tube) I pushed some sections of very soft neoprene tubing up inside the wand.

How do you make sure you can later remove the neoprene without hurting the tonearm wires? Or in any case, what would be the steps needed to rewire a tonearm that was modded in such way?

 

[flavio81]

Thanks for the warning. I'll wear an N95 facemask while viewing.

View attachment 3237651

I'd suggest everyone who wants to watch that video, to NOT read the misleading/biasing on-screen titles nor listen to the guy's rants.

For example at 2:38 i can hear some sibilance/mistracking on the lyrics "it was made up in your mind" on the Technics, while the Rega tracks it just fine. And the bass response is better on the Rega on that part of the video, despite the guy claiming -at the very same moment- hat the Technics has much better bass response.

In fact this video made me think the Rega P3 is much better than I thought. I was expecting the Technics to blow away the P3 for the advantages commonly attributed to high-torque direct drive turntables like great bass punch. Yet the -annoying- presenter can't stop loudmouthing about how much superior the SL-1200 is.

I feel like i'm taking crazy pills!!

 

[Mr Boochie]

I'd suggest everyone who wants to watch that video, to NOT read the misleading/biasing on-screen titles nor listen to the guy's rants.

For example at 2:38 i can hear some sibilance/mistracking on the lyrics "it was made up in your mind" on the Technics, while the Rega tracks it just fine. And the bass response is better on the Rega on that part of the video, despite the guy claiming -at the very same moment- hat the Technics has much better bass response.

In fact this video made me think the Rega P3 is much better than I thought. I was expecting the Technics to blow away the P3 for the advantages commonly attributed to high-torque direct drive turntables like great bass punch. Yet the -annoying- presenter can't stop loudmouthing about how much superior the SL-1200 is.

I feel like i'm taking crazy pills!!

View attachment 3237652

I hope people don't use one YouTube video as the only source of review of any product.

But you know how this game works. The presenter has to try to convince you that his opinions are meaningful to YOU (singular). So, much of the video is of the guy doing non-review stuff to show you he's doing things you like or would like to do. His general opinions agree with YOU. To connect with YOU.

Once that is done, his opinions become much more relevant to YOU (singular). If you don't like the extraneous stuff to get your attention (get your "like"), the YouTuber's opinions of the product may not be as relevant to YOU.

 

[tothmes]

Sorry if this is already obvious to everybody here:

The basic idea behind the isolated arm design is to break up one large resonance frequency peak from the entire arm tube into two (higher) frequencies, with an added damping. According to the theory from that time, that does reduce the overall resonances of the arm assembly. Of course contemporary texts never touch upon any negative effects from that damping, just accepting it as an unproblematic improvement.

I tried to look through my archive for a better technical paper about this, but only came up with one small bitty available at VE: https://www.vinylengine.com/turntable_forum/viewtopic.php?f=46&t=45688

Apart from Korf I haven't found any good technical info on the more modern take on this, by diverting the vibrations into the deck - only the common audiophile folklore and sales pitches. I'l love any links to something substantial. I've not read the Rega / Roy Gandy book. It perhaps has something interesting?

 

[tothmes]

Not just Michell, but just about every other aftermarket provider extant. At most it's metal on metal; at least it's a hard plastic like nylon, teflon or acetal.... similar to the mod made to your SME. None that I'm aware of retain the soft compliance of the original....they can't all be wrong.

This also means they're easier and cheaper to make, just simple metal on metal that can be produced by programming the CNC machine and just polishing out the finishing parts.

Most likely they all want to make a easy-to-make, cheap-to-produce product.

Obviously I'm not a neutral part in this discussion, but I tend to agree with @flavio81 here.

What is prohibitively expensive in replacement turntable parts nowadays is custom rubber parts, since those can never be made in small series unless one figures out how to make them by hand (yes, this is a shameless plug...). Apart from specialised 3d-printing - with its so far considerable limitations in softer materials - there is no halfway stop between industrial production in the tenths of thousand parts, and hand casting. On the other hand you can easily churn out perfectly fitting parts in metal and harder plastics with a cheap cnc rig. So when you see somebody suggesting replacing a rubber damper with a much harder part you must ask yourself if this actually is a new technical solution to an old problem, or just cost cutting.

I haven't tried out any of the available mods on any of my Rega arms, but I would expect them to actually have good enough bearings and mechanics to be able to handle any increased vibrations from reduced damping. So I don't have any general objections to using harder coupled parts on that type of modern arms.

But replacing an isolator with a hard coupler from an arm with knife edge bearings, or from an arm with simpler ball bearings with a notable play is another ball game. The transmission of the arm vibrations just isn't going to happen through those bearings - instead they will stay in the arm tube, more or less making the arm ring, with effects like the sibilance flavio81 reported. Of course this will be only worsened in arms with flimsy armtubes, pillars, and mounts against the plinth - even more if any of those have (plastic) parts with contrasting mechanical impedances to the metal parts of the arm along the way the transmission was supposed to pass.

This is also one reason I've been looking for technical info on the modern vibration handling in tonearms. Since it does require much firmer bearings than the damped design, my guess is that a fair bit of the development in these bearings in the last decades is in fact due to vibration handling, and not only to how easily they make the arm move.

So, we are mostly in agreement. We all want better dynamics and less sibilance. But we can't use the same methods on all tonearms.

 

[ripblade]

We're assuming the modification works. I would like perhaps more evidence, even if it's anecdotal.

I can think of no other hifi product that has spawned so many aftermarket variables on a single theme. That alone should be anecdotal enough, but if you need more evidence you have to try it yourself, which, judging by the offhand dismissals you listed above, prove you haven't. The Rega stock CWs are turned on a lathe, no expensive CNC machine required. Every single one of the aftermarket CW is more complex, thus more expensive to make, not cheaper. Using O-rings lessens the need for tight tolerances, again, cheaper to make.

 

[ripblade]

So, we are mostly in agreement. We all want better dynamics and less sibilance. But we can't use the same methods on all tonearms

That's what I wrote in my first post up thread. I guess the Rega is a bit of a unicorn.

Y'know it's funny: hard mounting the CW is one of the most common and effective upgrades for Rega arms. Those little rubber O-rings are doing the arm no good. But, the SME is completely different from a Rega, so needs different fixes to control resonances .

 

[T68]

I use tungsten clay in the CW on my diy tonearm. I suppose that solves both mass and damping.

 

[tothmes]

That's what I wrote in my first post up thread. I guess the Rega is a bit of a unicorn.

I have a hunch the Rega arms may be intentionally built with a bit of internal damping, due to the lightweight Rega mdf plinths lacking in their capacity to absorb too much of vibrations from the arm. Especially with the mechanical impedance between the arm pillar and the phenolic/mdf surface on the the plinth recoiling much of the vibrations back into the arm. It would make sense to see those arms as optimised as a part of the total design of the decks they are primarily built for. If so, the same arms mounted on different plinths would of course allow for more of reduction of the damping.

This idea is purely speculative, and could be easily refuted if there is a consensus about reduced damping of the arms making for at least as much improvement on Rega decks as on non-regas. I don't follow the Rega world so closely; I mostly try to buy them second hand cheaply, rip their arms off for better use and then sell off the remains...

Then of course there is a historic perspective on those arms - they were originally conceived at about the time of the demise of the damped/isolated arm era. Some of the older ideas may have survived into their original design. After all, not everybody want their music with maximal dynamics and timing - there has always been a market for more of a cocktail hour sound.

 

[tothmes]

I use tungsten clay in the CW on my diy tonearm. I suppose that solves both mass and damping.

What is that, and how does it work? Sounds interesting, but I admit I've never heard of it.

 

[flavio81]

I can think of no other hifi product that has spawned so many aftermarket variables on a single theme. That alone should be anecdotal enough, but if you need more evidence you have to try it yourself, which, judging by the offhand dismissals you listed above, prove you haven't.

I was asking for firsthand experiences of the improvements of going to a rigid counterweight coupling.

The Rega stock CWs are turned on a lathe, no expensive CNC machine required. Every single one of the aftermarket CW is more complex, thus more expensive to make, not cheaper. Using O-rings lessens the need for tight tolerances, again, cheaper to make.

Ok, sounds plausible.

 

[Powertech]

How do you make sure you can later remove the neoprene without hurting the tonearm wires? Or in any case, what would be the steps needed to rewire a tonearm that was modded in such way?

The arm was completely stripped down. A lead wire was threaded through the neoprene tubing before it was pulled into the arm tube. The tubing was lubricated with petroleum jelly to help it slide through the arm tube. The tonearm wires were pulled through the arm (and internal tubing) afterwards using the lead wire and then the arm was rebuilt. The wiring could now be replaced, as normal, without fully stripping the arm.

 

[flavio81]

So, we are mostly in agreement. We all want better dynamics and less sibilance. But we can't use the same methods on all tonearms.

Agree, not all methods will work as well on any kind of tonearm.

Now, for a funny follow up to my experience with the SME 3009/II...

I installed the OC9XEB cartridge there, with the same LH11H headshell. 2.0g VTF.

I noticed that there was a slight sibilance on some challenging tracks of a record (Ruben Blades - Buscando America). Some slight sound of effort on the highest modulated parts of the vocals. This was using A/B comparison with the same track(s) sourced from Tidal.

I tried using the foam isolator on the headshell -- no improvement. Removed the isolator, went for solid coupling -- no improvement.

I then went back again to the ADC XLM II Improved cartridge, brand new stylus, 1.25g VTF. Sibilance absolutely gone, very natural, good sound. So I theorized that the MC was transmitting way too much energy to the tonearm.

I switched turntables, and installed the OC9XEB on the SME 3009/III (Series III tonearm). Clear tracking, clear as a bell, problem gone.

The fun stuff here is how arm mass and/or perceived compliance seems to mean nothing.

I had the SME 3009 II (circa 16-18g, when you consider the 11g headshell) work perfectly fine with the very-high-compliance ADC, poor with the MC OC9XEB, which -if compliance figures are to be believed- is a high compliance cartridge too, just not so high as the ADC.

Yet the SME 3009 III (5g effective arm mass including fixed headshell) was a very good match to the OC9XEB...

It all shows that it is more about how the cartridge actually behaves, than a compliance figure versus an arm mass figure.

So going back to what @tothmes wrote, tonearms are not equal. The SME III has no flexible coupling at all, it's all rigid from headshell down to the counterweight, as far as I can see.

 

[ripblade]

I was asking for firsthand experiences of the improvements of going to a rigid counterweight coupling.

The web is full of them, but if you wish to experience it yourself without too much costly outlay you could try the hardware headshell damper mentioned in the thread I linked to above. The improvements brought about by it are quite similar to those brought about by the CW mod but are not mutually exclusive; in fact, both together is more synergistic IMO, bringing the arm closer to its fullest potential.

I have a hunch the Rega arms may be intentionally built with a bit of internal damping, due to the lightweight Rega mdf plinths lacking in their capacity to absorb too much of vibrations from the arm. Especially with the mechanical impedance between the arm pillar and the phenolic/mdf surface on the the plinth recoiling much of the vibrations back into the arm. It would make sense to see those arms as optimised as a part of the total design of the decks they are primarily built for. If so, the same arms mounted on different plinths would of course allow for more of reduction of the damping.

In fact, it has none, that's why Audiomods added bulkheads and drilled holes, and Michell added foam. I think it's also why the CW mod works so well because the tight coupling acts to limit (damp) vibrations.

The Rega philosophy is to rigidly pass all resonances into the plinth, but as you say, the plinth is not massive enough to ensure the energy is fully attenuated and not returned to the arm. That may be another reason the structural improvements to the arm pay dividends but they will no matter what deck it is mounted on.

 

[ripblade]

The SME III has no flexible coupling at all, it's all rigid from headshell down to the counterweight, as far as I can see.

The wand decouples at the base for interchangeability. But, the whole thing (excluding the wand pipe itself) is composite plastic, so there's some kind of compliance going on there, at least in terms of limiting energy transfer to the bearings through reduced rigidity.

 

[tothmes]

In fact, it has none, that's why Audiomods added bulkheads and drilled holes, and Michell added foam. I think it's also why the CW mod works so well because the tight coupling acts to limit (damp) vibrations.

Of course! Sorry, I was thinking of the 250 arm, and forgot about the 300 counterweight which is undamped if I remember it correctly (Mine is tucked away right now). But now I'm more confused about what you wrote before:

"Not just Michell, but just about every other aftermarket provider extant. At most it's metal on metal; at least it's a hard plastic like nylon, teflon or acetal.... similar to the mod made to your SME. None that I'm aware of retain the soft compliance of the original....they can't all be wrong." (sorry for the ugly quote, couldn't get it right...).

That gave me the impression you meant the aftermarket stuff reduced the damping of the Rega originals, which would make sense for the 250, but not for the 300 as I remember it. What am I missing?