So, this might be something that I wind up answering myself, but I'm curious as to what others think about this.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
Note that I've encountered very few (if any) issues with my 1200/OC9 combo that I can attribute to the 6.2hz resonance.
At the same time, it seems like, in regards to tonearm choices, people really don't care all that much about tonearm resonance issues. The Jelco tonearms, particularly the SA-750, are considered very exceptional tonearm upgrades for the SL-1200, even for an OC9. And yet, it has an effective mass of 18g - 7g higher than the stock arm! The resonance goes down to 5.3hz! Granted, the 750 has fluid damping, but still... Similarly the low-mass arms like the SME III, Black Widow, etc are just not all that highly favored nowadays, even for high compliance carts. Hell... AT runs their OC9 frequency response tests on an AT 1010 tonearm, and that's 16g, with no damping.
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this? I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
Full Version: What is the importance of cart-arm matching?
I've always understood that it's the effect these resonances have on the rest of your system that's the problem. At the resonant frequency - which, as you point out will usually be sub-sonic - large amounts of energy are produced by your cartridge and your amplifier and speakers will try to reproduce it. Your amp may well succeed but in doing so could run out of steam, leaving nothing available for the audible signal it's also trying to amplify, leading to distortion. Your speakers will almost certainly not be able to reproduce the resonant frequency but the cones will flap about uncontrollably in the attempt and so also introduce distortion - I'm not sure if damage can result from the cones hitting their end stops and there may also be some unwanted interaction from the speakers back to the amp.
Having said that I've also always understood that the RIAA/IEEE playback eq standard specifies a "warp filter" cutting in at 40hZ IIRC so it shouldn't be that much of a problem except in severe cases where lf energy exceeds the capacity of the warp filter to deal with it.
If you want to try to ABX the effect you could record something from a badly warped record and then run it through a steep filter to remove any subsonics. You could then playback the files at a highish volume so that any effects on your amp and speakers should be more noticeable (but I expect you've thought of that). I'm not sure if using headphones for this would be as effective
Having said that I've also always understood that the RIAA/IEEE playback eq standard specifies a "warp filter" cutting in at 40hZ IIRC so it shouldn't be that much of a problem except in severe cases where lf energy exceeds the capacity of the warp filter to deal with it.
If you want to try to ABX the effect you could record something from a badly warped record and then run it through a steep filter to remove any subsonics. You could then playback the files at a highish volume so that any effects on your amp and speakers should be more noticeable (but I expect you've thought of that). I'm not sure if using headphones for this would be as effective
There's an IEC addendum for a rumble rolloff starting at 20hz but it is not standard.
I guess if I were actually using an analog playback kit to play my vinyl, I would, but I'm not - it's entirely computer based and there are no speakers. So the amp/woofer issue is moot.
With a record that warped, I'm basically just listening for wow and tracing/tracking distortion. I suppose I could try deliberately warping a record to see how it does before/after.
I guess if I were actually using an analog playback kit to play my vinyl, I would, but I'm not - it's entirely computer based and there are no speakers. So the amp/woofer issue is moot.
With a record that warped, I'm basically just listening for wow and tracing/tracking distortion. I suppose I could try deliberately warping a record to see how it does before/after.
QUOTE (Axon @ Mar 25 2009, 17:31) 
So, this might be something that I wind up answering myself, but I'm curious as to what others think about this.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
The solution is to get a tonearm with less intertia, or a cartridge with less compliance.
"If its not broke, don't fix it".
QUOTE (Arnold B. Krueger @ Mar 28 2009, 12:42)
The solution is to get a tonearm with less intertia, or a cartridge with less compliance. "If its not broke, don't fix it".
Sure. So where can I buy a currently manufactured tonearm with a 4g effective mass?
QUOTE (Axon @ Mar 25 2009, 22:31)
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this?
Why do you expect audiophiles to discuss/respect matters in the order of most relevance to sound quality? Many will happily tell you that the type of turntable drive is far more important to the sound than the cartridge. The overwhelming majority of people with a strong interest in turntables these days seem to have little interest in sound quality in any real sense.
QUOTE (Axon @ Mar 25 2009, 22:31)
I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
What would you measure: a perceived difference or a perceived sound quality?
How would you determine your input signal in order to calculate distortion?
QUOTE (honestguv @ Mar 30 2009, 03:11)
QUOTE (Axon @ Mar 25 2009, 22:31)
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this?
Why do you expect audiophiles to discuss/respect matters in the order of most relevance to sound quality? Many will happily tell you that the type of turntable drive is far more important to the sound than the cartridge. The overwhelming majority of people with a strong interest in turntables these days seem to have little interest in sound quality in any real sense.
Just because most people are drinking the kool-aid, doesn't mean there's a real issue here.
QUOTE
QUOTE (Axon @ Mar 25 2009, 22:31)
I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
What would you measure: a perceived difference or a perceived sound quality? How would you determine your input signal in order to calculate distortion?
Perceived differences should be fairly easily correlatable to perceived sound quality. I'd probably take a subjective commentary on a positive ABX test and relate that to the known distortion modes of the two arms. This isn't much different from how MP3 results are interpreted. This is trivial for warp wow and only slightly less so for deflection-induced distortion. For acoustic differences, I would take cues from the subjective evaluation of early room reflections, or possibly even extrapolate from the minimum/maximum phase filter discussion done here a few months ago.
Longer term I'm thinking simulation, but that's obviously a bigger bone to chew...
> That's selling a lot of people short. Lipshitz himself did a lot of work on
> this exact problem (cart-arm resonance and damping) in the 70s.
The 1970s is not today. At that time, record players were produced in large numbers because they were the principle means to reproduce a personal choice of music in the home. There was a commercial advantage in developing technically better record players although the end of the hi-fi boom, the cost/performance of Asian imports, the growing success of the new audiophile approach, the failure of 4 channel records, the imminent replacement by superior technology all meant that the interest was not strong.
As I recall, development at this time was in the direction of smaller lower mass cartridge/arms able to track significantly higher velocities. For this improved performance to make sense, records would need to be cut at higher velocities causing problems for existing heavier stiffer cartridge/arms. This was never going to happen because record players as a technology were over in the same way CRT display investment and development ended years before LCD displays dominated the market.
Turntables today are produced and marketed for people with little interest in real sound quality and this is reflected in their design. Looks dominate function. If performance was important then:
- turntables would operate in a sealed box to reduce air-borne vibration
- turntables would be isolated from structure-borne vibration on long soft straps
- parallel tracking would be used to remove geometric distortion
- optical reading would be used to remove many sources of distortion
In fact, if you gave a competent engineer the task of reading the information from a record groove today they are likely to come up with something like optically scanning the surface, reconstructing the signal, fixing it for deficiencies and storing it digitally for convenient playback without any future degradation. I suspect that most audiophiles with a strong interest in record players today would have no interest in such an approach. It is not why audiophiles buy record players.
Of course, there are people with a pragmatic interest in records. Perhaps, as in my case, they have a record collection from decades ago and are only slowly transferring it to digital because the process is time consuming and not enjoyable. Others, perhaps those who are not prepared to steal music from internet, use records as a cheap source of music, or a source of a wider range of music, or older music, or less compressed recordings, etc... But this has little to do with sound quality.
> SME went from one extreme (ultra low mass arms, good compliance match) to the
> other extreme (damped, medium mass, high acoustic quality, worse compliance
> match) in the 80s.
For the first couple of decades SME arms were medium mass, then briefly they had a low mass model, and for the last few decades medium mass arms. Low mass arms are for light high compliance cartridges.
> Hi-Fi World continues to do accelerometer measurements that quite measurably
> show acoustic differences between very expensive arms that have a
> psychoacoustically plausible relationship to sound quality.
An audiophile magazine that plausibly discusses pyshoacoustics? Have I misunderstood your point since I am fairly sure this would be commercial suicide for any audiophile publication. A belief in audiophile magic is required in order to distinguish most, though not all, of the products.
> Just because most people are drinking the kool-aid, doesn't mean there's a
> real issue here.
I am not sure I understand the issue.
> Well, I'd first bug WmAx again for him to post his tonearm shootout samples, with
> the same tonearm and cartridge but different arms. <nudge> <nudge>
I do not fully understand this either.
> Perceived differences should be fairly easily correlatable to perceived sound
> quality.
You would seem to be more confident than I would be. Do you understand/believe that many audiophiles like the "sound" of a record player? Do you know why because I am not sure I do.
> I'd probably take a subjective commentary on a positive ABX test and relate that
> to the known distortion modes of the two arms.
If you see a big nasty sharp resonance or a small shallow hump in a frequency response which is going to be the more noticeable? That is, how do you choose among all the various distortions in the arm response and will the other distortions that are not visible in a tonearm response be unchanged when the tonearm is changed?
> This isn't much different from how MP3 results are interpreted.
When testing MP3s what has changed is usually unambiguous.
> This is trivial for warp wow and only slightly less so for deflection-induced
> distortion.
What do you mean by deflection induced distortion?
> For acoustic differences, I would take cues from the subjective evaluation of
> early room reflections, or possibly even extrapolate from the minimum/maximum
> phase filter discussion done here a few months ago.
I am not sure I understand.
> Longer term I'm thinking simulation, but that's obviously a bigger bone to
> chew...
If you wish to disentangle the various distortion generating mechanisms and try to relate them to what one can hear and see in the measurements then this is the obvious thing to do. It is likely to be reasonably straightforward if you have a reasonable level of engineering knowledge, access to suitable software and details of the construction of the cartridge, tonearm, turntable and environment.
The audiophile industry is low-tech and strongly marketing orientated and, unlike other medium-tech and high-tech areas of engineering, it generally does not work like this because it is unnecessary in order to be commercially successful. Even loudspeakers which is perhaps the area that would benefit most from a fundamental view are strongly locked into empirically based design methods. One or two of the larger companies publish/promote bits of work but I am not sure how much is really used internally as part of the design process.
> this exact problem (cart-arm resonance and damping) in the 70s.
The 1970s is not today. At that time, record players were produced in large numbers because they were the principle means to reproduce a personal choice of music in the home. There was a commercial advantage in developing technically better record players although the end of the hi-fi boom, the cost/performance of Asian imports, the growing success of the new audiophile approach, the failure of 4 channel records, the imminent replacement by superior technology all meant that the interest was not strong.
As I recall, development at this time was in the direction of smaller lower mass cartridge/arms able to track significantly higher velocities. For this improved performance to make sense, records would need to be cut at higher velocities causing problems for existing heavier stiffer cartridge/arms. This was never going to happen because record players as a technology were over in the same way CRT display investment and development ended years before LCD displays dominated the market.
Turntables today are produced and marketed for people with little interest in real sound quality and this is reflected in their design. Looks dominate function. If performance was important then:
- turntables would operate in a sealed box to reduce air-borne vibration
- turntables would be isolated from structure-borne vibration on long soft straps
- parallel tracking would be used to remove geometric distortion
- optical reading would be used to remove many sources of distortion
In fact, if you gave a competent engineer the task of reading the information from a record groove today they are likely to come up with something like optically scanning the surface, reconstructing the signal, fixing it for deficiencies and storing it digitally for convenient playback without any future degradation. I suspect that most audiophiles with a strong interest in record players today would have no interest in such an approach. It is not why audiophiles buy record players.
Of course, there are people with a pragmatic interest in records. Perhaps, as in my case, they have a record collection from decades ago and are only slowly transferring it to digital because the process is time consuming and not enjoyable. Others, perhaps those who are not prepared to steal music from internet, use records as a cheap source of music, or a source of a wider range of music, or older music, or less compressed recordings, etc... But this has little to do with sound quality.
> SME went from one extreme (ultra low mass arms, good compliance match) to the
> other extreme (damped, medium mass, high acoustic quality, worse compliance
> match) in the 80s.
For the first couple of decades SME arms were medium mass, then briefly they had a low mass model, and for the last few decades medium mass arms. Low mass arms are for light high compliance cartridges.
> Hi-Fi World continues to do accelerometer measurements that quite measurably
> show acoustic differences between very expensive arms that have a
> psychoacoustically plausible relationship to sound quality.
An audiophile magazine that plausibly discusses pyshoacoustics? Have I misunderstood your point since I am fairly sure this would be commercial suicide for any audiophile publication. A belief in audiophile magic is required in order to distinguish most, though not all, of the products.
> Just because most people are drinking the kool-aid, doesn't mean there's a
> real issue here.
I am not sure I understand the issue.
> Well, I'd first bug WmAx again for him to post his tonearm shootout samples, with
> the same tonearm and cartridge but different arms. <nudge> <nudge>
I do not fully understand this either.
> Perceived differences should be fairly easily correlatable to perceived sound
> quality.
You would seem to be more confident than I would be. Do you understand/believe that many audiophiles like the "sound" of a record player? Do you know why because I am not sure I do.
> I'd probably take a subjective commentary on a positive ABX test and relate that
> to the known distortion modes of the two arms.
If you see a big nasty sharp resonance or a small shallow hump in a frequency response which is going to be the more noticeable? That is, how do you choose among all the various distortions in the arm response and will the other distortions that are not visible in a tonearm response be unchanged when the tonearm is changed?
> This isn't much different from how MP3 results are interpreted.
When testing MP3s what has changed is usually unambiguous.
> This is trivial for warp wow and only slightly less so for deflection-induced
> distortion.
What do you mean by deflection induced distortion?
> For acoustic differences, I would take cues from the subjective evaluation of
> early room reflections, or possibly even extrapolate from the minimum/maximum
> phase filter discussion done here a few months ago.
I am not sure I understand.
> Longer term I'm thinking simulation, but that's obviously a bigger bone to
> chew...
If you wish to disentangle the various distortion generating mechanisms and try to relate them to what one can hear and see in the measurements then this is the obvious thing to do. It is likely to be reasonably straightforward if you have a reasonable level of engineering knowledge, access to suitable software and details of the construction of the cartridge, tonearm, turntable and environment.
The audiophile industry is low-tech and strongly marketing orientated and, unlike other medium-tech and high-tech areas of engineering, it generally does not work like this because it is unnecessary in order to be commercially successful. Even loudspeakers which is perhaps the area that would benefit most from a fundamental view are strongly locked into empirically based design methods. One or two of the larger companies publish/promote bits of work but I am not sure how much is really used internally as part of the design process.
QUOTE (Axon @ Mar 29 2009, 20:24)
QUOTE (Arnold B. Krueger @ Mar 28 2009, 12:42)
The solution is to get a tonearm with less intertia, or a cartridge with less compliance. "If its not broke, don't fix it".
Sure. So where can I buy a currently manufactured tonearm with a 4g effective mass?Take a Dremyl tool to the tonearm you got? ;-)
QUOTE (honestguv @ Apr 1 2009, 03:14)
The 1970s is not today. At that time, record players were produced in large numbers because they were the principle means to reproduce a personal choice of music in the home. There was a commercial advantage in developing technically better record players although the end of the hi-fi boom, the cost/performance of Asian imports, the growing success of the new audiophile approach, the failure of 4 channel records, the imminent replacement by superior technology all meant that the interest was not strong.
Just because the research didn't thrive doesn't mean the questions are answered or are not worth answering. I prefer to see the whole discussion from a hobbyist point of view, at least when it suits me. QUOTE
In fact, if you gave a competent engineer the task of reading the information from a record groove today they are likely to come up with something like optically scanning the surface, reconstructing the signal, fixing it for deficiencies and storing it digitally for convenient playback without any future degradation. I suspect that most audiophiles with a strong interest in record players today would have no interest in such an approach. It is not why audiophiles buy record players.
You're not the first person to say "well any engineer looking rationally at the situation would do things completely differently than those crazies in the hi-fi world do". But just by making those statements you're making engineering calls about the relative importance of various failure/distortion modes that, frankly, require justification. How much energy is transferred from the air to the pickup via the tonearm? How is that affected by tonearm materials and pickup compliance? How much better is a sealed box compared to a dust cover? How can optical scanning achieve a SNR exceeding that of the medium (70db below 100um) while avoiding the real issues with laser pickups? How does the reduced distortion from linear tracking compare to increased distortion modes particular to implementations of that system? And most of all, how can all this be done while satisfying the needs of the market (looking decent in a living room and being any more cost effective than what is already out there?)QUOTE
For the first couple of decades SME arms were medium mass, then briefly they had a low mass model, and for the last few decades medium mass arms. Low mass arms are for light high compliance cartridges.
Not true, the Series II Improved was also low mass. Although I think that too was a late 70s model.QUOTE
An audiophile magazine that plausibly discusses pyshoacoustics? Have I misunderstood your point since I am fairly sure this would be commercial suicide for any audiophile publication. A belief in audiophile magic is required in order to distinguish most, though not all, of the products.
What I meant to say was, they post accelerometer measurements and claim that they measure audible distortions, and while they haven't really proved their case, it is a plausible one.QUOTE
You would seem to be more confident than I would be. Do you understand/believe that many audiophiles like the "sound" of a record player? Do you know why because I am not sure I do.
I honestly don't care. I'm talking strictly about taking isolated distortion mechanisms and comparing their audible magnitude. I don't think I need to resort to subjective sound preferences to discuss that.I'm not asking these questions to necessarily influence the market (although that would be great) - at the lowest level, I'm seriously looking at an arm upgrade, and I want to gauge my odds of actually needing it, what I'm missing out on, if it's all placebo, etc. And tonearms are enough of mechanical devices to not have their flaws dismissed out of hand.
QUOTE
If you see a big nasty sharp resonance or a small shallow hump in a frequency response which is going to be the more noticeable? That is, how do you choose among all the various distortions in the arm response and will the other distortions that are not visible in a tonearm response be unchanged when the tonearm is changed?
There aren't *that* many other distortions that are going to change with a change in tonearm: the cart-arm resonance changes, the alignment has been destroyed, and the coupling between the cart and the air/plinth has changed. I think all of those can be isolated in a rational analysis of the situation.QUOTE
When testing MP3s what has changed is usually unambiguous.
That's not always categorically true, at least in the case of codec regressions. Look at Vorbis's old treble boost bug for instance.QUOTE
What do you mean by deflection induced distortion?
Dynamic changes in tracking distortion due to dynamic changes in VTF and/or skating forces due to wow.QUOTE
If you wish to disentangle the various distortion generating mechanisms and try to relate them to what one can hear and see in the measurements then this is the obvious thing to do. It is likely to be reasonably straightforward if you have a reasonable level of engineering knowledge, access to suitable software and details of the construction of the cartridge, tonearm, turntable and environment.
Well, I have an engineering background, but not in what I think is necessary. I don't have any training in vibration analysis/simulation. Pointers gladly taken.QUOTE
The audiophile industry is low-tech and strongly marketing orientated and, unlike other medium-tech and high-tech areas of engineering, it generally does not work like this because it is unnecessary in order to be commercially successful. Even loudspeakers which is perhaps the area that would benefit most from a fundamental view are strongly locked into empirically based design methods. One or two of the larger companies publish/promote bits of work but I am not sure how much is really used internally as part of the design process.
Again, this is a shame, but I'm sort of committed to vinyl as a hobby, and I'm trying to answers these questions rationally in that context. If they weren't so secretive with their own measurements (and/or gave truly rational justifications for their design decisions), I wouldn't be asking these questions in the first place. But reading old JAES stuff gives me hope that at least somebody has dwelled on these things before.
QUOTE (Arnold B. Krueger @ Apr 1 2009, 10:30)
QUOTE (Axon @ Mar 29 2009, 20:24)
QUOTE (Arnold B. Krueger @ Mar 28 2009, 12:42)
The solution is to get a tonearm with less intertia, or a cartridge with less compliance. "If its not broke, don't fix it".
Sure. So where can I buy a currently manufactured tonearm with a 4g effective mass?Take a Dremyl tool to the tonearm you got? ;-)
QUOTE (Axon @ Mar 25 2009, 13:31)
So, this might be something that I wind up answering myself, but I'm curious as to what others think about this.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
Note that I've encountered very few (if any) issues with my 1200/OC9 combo that I can attribute to the 6.2hz resonance.
At the same time, it seems like, in regards to tonearm choices, people really don't care all that much about tonearm resonance issues. The Jelco tonearms, particularly the SA-750, are considered very exceptional tonearm upgrades for the SL-1200, even for an OC9. And yet, it has an effective mass of 18g - 7g higher than the stock arm! The resonance goes down to 5.3hz! Granted, the 750 has fluid damping, but still... Similarly the low-mass arms like the SME III, Black Widow, etc are just not all that highly favored nowadays, even for high compliance carts. Hell... AT runs their OC9 frequency response tests on an AT 1010 tonearm, and that's 16g, with no damping.
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this? I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
Note that I've encountered very few (if any) issues with my 1200/OC9 combo that I can attribute to the 6.2hz resonance.
At the same time, it seems like, in regards to tonearm choices, people really don't care all that much about tonearm resonance issues. The Jelco tonearms, particularly the SA-750, are considered very exceptional tonearm upgrades for the SL-1200, even for an OC9. And yet, it has an effective mass of 18g - 7g higher than the stock arm! The resonance goes down to 5.3hz! Granted, the 750 has fluid damping, but still... Similarly the low-mass arms like the SME III, Black Widow, etc are just not all that highly favored nowadays, even for high compliance carts. Hell... AT runs their OC9 frequency response tests on an AT 1010 tonearm, and that's 16g, with no damping.
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this? I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
FWIW, my Dual 721 semi-auto table has a damped counterwieght to attemp to deal with arm resonance. AFAIK the counterweight tuning is not user adjustable. The Shure V15 type V cartridge (IMO best moving magnet ever made) has a fluid damped brush on the front to clean the disc on the fly and damp out arm/cartridge resonance issues. I CAN state that warped discs that caused other tables problems played just fine on the Shure / Dual combination. I never found a disc that would play on some other brand table and _not_ work correctly on the Shure / Dual combination. Yes I still have it but the only discs I have left are the direct-to-disc recordings. I do NOT miss turnables and all the annoyances that go with them.
G²
QUOTE (Axon @ Apr 1 2009, 13:40)
QUOTE (Arnold B. Krueger @ Apr 1 2009, 10:30)
QUOTE (Axon @ Mar 29 2009, 20:24)
QUOTE (Arnold B. Krueger @ Mar 28 2009, 12:42)
The solution is to get a tonearm with less intertia, or a cartridge with less compliance. "If its not broke, don't fix it".
Sure. So where can I buy a currently manufactured tonearm with a 4g effective mass?Take a Dremyl tool to the tonearm you got? ;-)
I don't take audiophile ideas, particularly about tone arms very seriouisly. Audiophile ideas are generally riddled with uninformed intuition and hype.
For example, in the old days many tone arms were made with counterweights that had compliant mounting so as to create a vibration absorber. Audiopile paranoia about tone arm vibration seems to have pretty well elimintated this idea which seems to have quite a bit of merit.
BTW, it might be worth the trouble to experiment with a vibration absorber created by mounting the counterweight in rubber or sorbothane.
As far as tone arm vibrations go, if they are there they will be measurable.
QUOTE (honestguv @ Apr 1 2009, 04:14)
Turntables today are produced and marketed for people with little interest in real sound quality and this is reflected in their design. Looks dominate function. If performance was important then:
- turntables would operate in a sealed box to reduce air-borne vibration
- turntables would be isolated from structure-borne vibration on long soft straps
- parallel tracking would be used to remove geometric distortion
- optical reading would be used to remove many sources of distortion
In fact, if you gave a competent engineer the task of reading the information from a record groove today they are likely to come up with something like optically scanning the surface, reconstructing the signal, fixing it for deficiencies and storing it digitally for convenient playback without any future degradation. I suspect that most audiophiles with a strong interest in record players today would have no interest in such an approach. It is not why audiophiles buy record players.
- turntables would operate in a sealed box to reduce air-borne vibration
- turntables would be isolated from structure-borne vibration on long soft straps
- parallel tracking would be used to remove geometric distortion
- optical reading would be used to remove many sources of distortion
In fact, if you gave a competent engineer the task of reading the information from a record groove today they are likely to come up with something like optically scanning the surface, reconstructing the signal, fixing it for deficiencies and storing it digitally for convenient playback without any future degradation. I suspect that most audiophiles with a strong interest in record players today would have no interest in such an approach. It is not why audiophiles buy record players.
I totally agree with this statement. I have several turntables and I own them much more for looks, build quality, and operation -- not performance. A compact disc may sound slightly better (to me), but it is far more enjoyable to interact with a turntable and vinyl records. A quality turntable is the most impressive looking piece in an audio setup.
Below, shows the two (of six) turntables that I use most...
In chemical laboratories the balances sit on thick granite tables to avoid the effects of vibration pickup when weighing. Don't you have the equivalent for your turntables? 
QUOTE (pdq @ Sep 17 2009, 12:17)
In chemical laboratories the balances sit on thick granite tables to avoid the effects of vibration pickup when weighing. Don't you have the equivalent for your turntables?
I'm in the packaging industry, so I am experimenting with corrugated fixtures. I don't have a granite table, but perhaps some slabs on the corrugated piece would be nice. Also, since the corrugated piece rests on a solid concrete slab, does that count?
I cannot dispute that those tables look awesome.
Since the OP talked about the "grand scheme of things", it seems to me that everything about turntables and arms and cartridges and such all combined into one thing is still of vanishingly small import in the real grand scheme.
QUOTE (Axon @ Mar 25 2009, 23:31)
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place,
FYI in the July issue HiFi News tested a handful of MCs, including compliance.
I don't have the magazine here, but the resonance measurements can be downloaded at Paul Miller's site.
Audio Technica AT-OC9ML/II
LF Resonance in 8g tonearm
Arm/Cartridge Resonance = +9dB @ 10Hz (Vertical)
Arm/Cartridge Resonance = +14dB @ 7Hz (Lateral)
http://www.milleraudioresearch.com/avtech/index.html
Be careful with that Stanton. It seems like the suspension has hardened up.
QUOTE (Axon @ Mar 25 2009, 23:31)
So, this might be something that I wind up answering myself, but I'm curious as to what others think about this.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
Note that I've encountered very few (if any) issues with my 1200/OC9 combo that I can attribute to the 6.2hz resonance.
At the same time, it seems like, in regards to tonearm choices, people really don't care all that much about tonearm resonance issues. The Jelco tonearms, particularly the SA-750, are considered very exceptional tonearm upgrades for the SL-1200, even for an OC9. And yet, it has an effective mass of 18g - 7g higher than the stock arm! The resonance goes down to 5.3hz! Granted, the 750 has fluid damping, but still... Similarly the low-mass arms like the SME III, Black Widow, etc are just not all that highly favored nowadays, even for high compliance carts. Hell... AT runs their OC9 frequency response tests on an AT 1010 tonearm, and that's 16g, with no damping.
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this? I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
My SL-1200/OC9 combo has a resonance at 6.2hz. Now, as is documented in that link, the common wisdom is that's impossible in the first place, but let's ignore that. 6.2hz is supposed to be way too low. The "optimum" resonance is somewhere in the 8hz-12hz range, as is documented in diverse references in JAES and audio mags. Anything significantly below 8hz will get excited by record warps and environmental noise/footfalls/etc. This is supposed to exacerbate issues with warp wow, mistracking, subwoofer pumping etc. Anything significantly above 12hz will get excited by the music, causing a pretty ridiculous bass boost on some carts (my Stanton 500 resonates at ~40hz, I kid you not, and it kind of sounds like a boom box at times). This can also cause mistracking issues.
Note that I've encountered very few (if any) issues with my 1200/OC9 combo that I can attribute to the 6.2hz resonance.
At the same time, it seems like, in regards to tonearm choices, people really don't care all that much about tonearm resonance issues. The Jelco tonearms, particularly the SA-750, are considered very exceptional tonearm upgrades for the SL-1200, even for an OC9. And yet, it has an effective mass of 18g - 7g higher than the stock arm! The resonance goes down to 5.3hz! Granted, the 750 has fluid damping, but still... Similarly the low-mass arms like the SME III, Black Widow, etc are just not all that highly favored nowadays, even for high compliance carts. Hell... AT runs their OC9 frequency response tests on an AT 1010 tonearm, and that's 16g, with no damping.
What I'm getting at here is, even though cart-tonearm compatibility is discussed a lot in the literature and among audiophiles, it really doesn't seem to be highly respected in comparison to other distortion effects - the most notable of which are the acoustic properties of the tonearm, and its high frequency resonances. Why, exactly, is this? I'd love to get some ABX action with this, but unfortunately those sorts of samples are extremely hard to come by atm.
first. don't take a grinder to your arm!! That is nuts. The point of trying to get the resonant frequency between 8 and 12 Hz is not *directly* related to "record warps and environmental noise/footfalls/etc." It is directly related to the resonant frequency of your suspension. Your suspension's resonant frequency is supposed to reduce the impact of footfall and envirmental noise while not being excited by warps and eccentric records. This puts the ideal range of that resonant frequency somewhere between 0.75 Hz and the resonant frequency of your arm/cartridge. So 8 to 12 Hz is based on assumptions about that figure. If the resonant frequency of your suspension is well below 6.2 Hz you shouldn't have a problem.
Basically you have two resonant frequencies that have to be spaced as far as possible from 0.5- 0.75 Hz to avoid rotational related excitement, 20Hz to avoid musical content related excitement and each other to avoid any interaction between the arm/cartirdge and the suspension of the turntable itself. IMO one has to worry more about sympthetic harmonics than the actual spacing of resonant frequencies.
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