Who needs a MM cartridge type when we have MC?


Dear friends: who really needs an MM type phono cartridge?, well I will try to share/explain with you what are my experiences about and I hope too that many of you could enrich the topic/subject with your own experiences.

For some years ( in this forum ) and time to time I posted that the MM type cartridge quality sound is better than we know or that we think and like four months ago I start a thread about: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1173550723&openusid&zzRauliruegas&4&5#Rauliruegas where we analyse some MM type cartridges.

Well, in the last 10-12 months I buy something like 30+ different MM type phono cartridges ( you can read in my virtual system which ones. ) and I’m still doing it. The purpose of this fact ( “ buy it “ ) is for one way to confirm or not if really those MM type cartridges are good for us ( music lovers ) and at the same time learn about MM vs MC cartridges, as a fact I learn many things other than MM/MC cartridge subject.

If we take a look to the Agon analog members at least 90% of them use ( only ) MC phono cartridges, if we take a look to the “ professional reviewers “ ( TAS, Stereophile, Positive Feedback, Enjoy the Music, etc, etc, ) 95% ( at least ) of them use only MC cartridges ( well I know that for example: REG and NG of TAS and RJR of Stereophile use only MM type cartridges!!!!!!!! ) , if we take a look to the phono cartridge manufacturers more than 90% of them build/design for MC cartridges and if you speak with audio dealers almost all will tell you that the MC cartridges is the way to go.

So, who are wrong/right, the few ( like me ) that speak that the MM type is a very good alternative or the “ whole “ cartridge industry that think and support the MC cartridge only valid alternative?

IMHO I think that both groups are not totally wrong/right and that the subject is not who is wrong/right but that the subject is : KNOW-HOW or NON KNOW-HOW about.

Many years ago when I was introduced to the “ high end “ the cartridges were almost MM type ones: Shure, Stanton, Pickering, Empire, etc, etc. In those time I remember that one dealer told me that if I really want to be nearest to the music I have to buy the Empire 4000 D ( they say for 4-channel reproduction as well. ) and this was truly my first encounter with a “ high end cartridge “, I buy the 4000D I for 70.00 dls ( I can’t pay 150.00 for the D III. ), btw the specs of these Empire cartridges were impressive even today, look: frequency response: 5-50,000Hz, channel separation: 35db, tracking force range: 0.25grs to 1.25grs!!!!!!!!, just impressive, but there are some cartridges which frequency response goes to 100,000Hz!!!!!!!!!!

I start to learn about and I follow to buying other MM type cartridges ( in those times I never imagine nothing about MC cartridges: I don’t imagine of its existence!!!. ) like AKG, Micro Acoustics, ADC, B&O, Audio Technica, Sonus, etc, etc.

Years latter the same dealer told me about the MC marvelous cartridges and he introduce me to the Denon-103 following with the 103-D and the Fulton High performance, so I start to buy and hear MC cartridges. I start to read audio magazines about either cartridge type: MM and Mc ones.

I have to make changes in my audio system ( because of the low output of the MC cartridges and because I was learning how to improve the performance of my audio system ) and I follow what the reviewers/audio dealers “ speak “ about, I was un-experienced !!!!!!!, I was learning ( well I’m yet. ).

I can tell you many good/bad histories about but I don’t want that the thread was/is boring for you, so please let me tell you what I learn and where I’m standing today about:

over the years I invested thousands of dollars on several top “ high end “ MC cartridges, from the Sumiko Celebration passing for Lyras, Koetsu, Van denHul, to Allaerts ones ( just name it and I can tell that I own or owned. ), what I already invest on MC cartridges represent almost 70-80% price of my audio system.

Suddenly I stop buying MC cartridges and decide to start again with some of the MM type cartridges that I already own and what I heard motivate me to start the search for more of those “ hidden jewels “ that are ( here and now ) the MM phono cartridges and learn why are so good and how to obtain its best quality sound reproduction ( as a fact I learn many things other than MM cartridge about. ).

I don’t start this “ finding “ like a contest between MC and MM type cartridges.
The MC cartridges are as good as we already know and this is not the subject here, the subject is about MM type quality performance and how achieve the best with those cartridges.

First than all I try to identify and understand the most important characteristics ( and what they “ means “. ) of the MM type cartridges ( something that in part I already have it because our phonolinepreamp design needs. ) and its differences with the MC ones.

Well, first than all is that are high output cartridges, very high compliance ones ( 50cu is not rare. ), low or very low tracking force ones, likes 47kOhms and up, susceptible to some capacitance changes, user stylus replacement, sometimes we can use a different replacement stylus making an improvement with out the necessity to buy the next top model in the cartridge line , low and very low weight cartridges, almost all of them are build of plastic material with aluminum cantilever and with eliptical or “ old “ line contact stylus ( shibata ) ( here we don’t find: Jade/Coral/Titanium/etc, bodies or sophisticated build material cantilevers and sophisticated stylus shape. ), very very… what I say? Extremely low prices from 40.00 to 300.00 dls!!!!!!!!!!!!!!!!!!, well one of my cartridges I buy it for 8.99 dls ( one month ago ): WOW!!!!!!, so any one of you can/could have/buy ten to twenty MM cartridges for the price of one of the MC cartridge you own today and the good notice is that is a chance that those 10-20 MM type cartridges even the quality performance of your MC cartridge or beat it.

Other characteristics is that the builders show how proud they were/are on its MM type cartridges design, almost all those cartridges comes with a first rate box, comes with charts/diagrams of its frequency response and cartridge channel separation ( where they tell us which test recording use it, with which VTF, at which temperature, etc, etc. ), comes with a very wide explanation of the why’s and how’s of its design and the usual explanation to mount the cartridge along with a very wide list of specifications ( that were the envy of any of today MC ones where sometimes we really don’t know nothing about. ), comes with a set of screws/nuts, comes with a stylus brush and even with stylus cleaning fluid!!!!!!!!!, my GOD. Well, there are cartridges like the Supex SM 100MK2 that comes with two different stylus!!!! One with spherical and one with elliptical/shibata shape and dear friends all those in the same low low price!!!!!!!!!!!

Almost all the cartridges I own you can find it through Ebay and Agon and through cartridge dealers and don’t worry if you loose/broke the stylus cartridge or you find the cartridge but with out stylus, you always can/could find the stylus replacement, no problem about there are some stylus and cartridge sources.

When I’m talking about MM type cartridges I’m refer to different types: moving magnet, moving iron, moving flux, electret, variable reluctance, induced magnet, etc, etc. ( here is not the place to explain the differences on all those MM type cartridges. Maybe on other future thread. ).

I made all my very long ( time consuming ) cartridge tests using four different TT’s: Acoustic Signature Analog One MK2, Micro Seiki RX-5000, Luxman PD 310 and Technics SP-10 MK2, I use only removable headshell S and J shape tonearms with 15mm on overhang, I use different material build/ shape design /weight headshells. I test each cartridge in at least three different tonearms and some times in 3-4 different headshells till I find the “ right “ match where the cartridge perform the best, no I’m not saying that I already finish or that I already find the “ perfect “ match: cartridge/headshell/tonearm but I think I’m near that ideal target.

Through my testing experience I learn/ confirm that trying to find the right tonearm/headshell for any cartridge is well worth the effort and more important that be changing the TT. When I switch from a TT to another different one the changes on the quality cartridge performance were/are minimal in comparison to a change in the tonearm/headshell, this fact was consistent with any of those cartridges including MC ones.

So after the Phonolinepreamplifier IMHO the tonearm/headshell match for any cartridge is the more important subject, it is so important and complex that in the same tonearm ( with the same headshell wires ) but with different headshell ( even when the headshell weight were the same ) shape or build material headshell the quality cartridge performance can/could be way different.

All those experiences told me that chances are that the cartridge that you own ( MC or MM ) is not performing at its best because chances are that the tonearm you own is not the best match for that cartridge!!!!!!, so imagine what do you can/could hear when your cartridge is or will be on the right tonearm???!!!!!!!!, IMHO there are ( till today ) no single ( any type at any price ) perfect universal tonearm. IMHO there is no “ the best tonearm “, what exist or could exist is a “ best tonearm match for “ that “ cartridge “, but that’s all. Of course that are “ lucky “ tonearms that are very good match for more than one cartridge but don’t for every single cartridge.

I posted several times that I’m not a tonearm collector, that I own all those tonearms to have alternatives for my cartridges and with removable headshells my 15 tonearms are really like 100+ tonearms : a very wide options/alternatives for almost any cartridge!!!!!!

You can find several of these MM type cartridges new brand or NOS like: Ortofon, Nagaoka, Audio Technica, Astatic, B&O, Rega, Empire, Sonus Reson,Goldring,Clearaudio, Grado, Shelter, Garrot, etc. and all of them second hand in very good operational condition. As a fact I buy two and even three cartridges of the same model in some of the cartridges ( so right now I have some samples that I think I don’t use any more. ) to prevent that one of them arrive in non operational condition but I’m glad to say that all them arrive in very fine conditions. I buy one or two of the cartridges with no stylus or with the stylus out of work but I don’t have any trouble because I could find the stylus replacement on different sources and in some case the original new replacement.

All these buy/find cartridges was very time consuming and we have to have a lot of patience and a little lucky to obtain what we are looking for but I can asure you that is worth of it.

Ok, I think it is time to share my performance cartridge findings:

first we have to have a Phonolinepreamplifier with a very good MM phono stage ( at least at the same level that the MC stage. ). I’m lucky because my Phonolinepreamplifier has two independent phono stages, one for the MM and one for MC: both were designed for the specifics needs of each cartridge type, MM or MC that have different needs.

we need a decent TT and decent tonearm.

we have to load the MM cartridges not at 47K but at 100K ( at least 75K not less. ).

I find that using 47K ( a standard manufacture recommendation ) prevent to obtain the best quality performance, 100K make the difference. I try this with all those MM type cartridges and in all of them I achieve the best performance with 100K load impedance.

I find too that using the manufacturer capacitance advise not always is for the better, till “ the end of the day “ I find that between 100-150pf ( total capacitance including cable capacitance. ) all the cartridges performs at its best.

I start to change the load impedance on MM cartridges like a synonymous that what many of us made with MC cartridges where we try with different load impedance values, latter I read on the Empire 4000 DIII that the precise load impedance must be 100kOhms and in a white paper of some Grace F9 tests the used impedance value was 100kOhms, the same that I read on other operational MM cartridge manual and my ears tell/told me that 100kOhms is “ the value “.

Before I go on I want to remember you that several of those MM type cartridges ( almost all ) were build more than 30+ years ago!!!!!!!! and today performs at the same top quality level than today MC/MM top quality cartridges!!!!!, any brand at any price and in some ways beat it.

I use 4-5 recordings that I know very well and that give me the right answers to know that any cartridge is performing at its best or near it. Many times what I heard through those recordings were fine: everything were on target however the music don’t come “ alive “ don’t “ tell me “ nothing, I was not feeling the emotion that the music can communicate. In those cartridge cases I have to try it in other tonearm and/or with a different headshell till the “ feelings comes “ and only when this was achieved I then was satisfied.

All the tests were made with a volume level ( SPL ) where the recording “ shines “ and comes alive like in a live event. Sometimes changing the volume level by 1-1.5 db fixed everything.

Of course that the people that in a regular manner attend to hear/heard live music it will be more easy to know when something is right or wrong.

Well, Raul go on!!: one characteristic on the MM cartridges set-up was that almost all them likes to ride with a positive ( little/small ) VTA only the Grace Ruby and F9E and Sonus Gold Blue likes a negative VTA , on the other hand with the Nagaoka MP 50 Super and the Ortofon’s I use a flat VTA.

Regarding the VTF I use the manufacturer advise and sometimes 0.1+grs.
Of course that I made fine tuning through moderate changes in the Azymuth and for anti-skate I use between half/third VTF value.

I use different material build headshells: aluminum, composite aluminum, magnesium, composite magnesium, ceramic, wood and non magnetic stainless steel, these cartridges comes from Audio Technica, Denon, SAEC, Technics, Fidelity Research, Belldream, Grace, Nagaoka, Koetsu, Dynavector and Audiocraft.
All of them but the wood made ( the wood does not likes to any cartridge. ) very good job . It is here where a cartridge could seems good or very good depending of the headshell where is mounted and the tonearm.
Example, I have hard time with some of those cartridge like the Audio Technica AT 20SS where its performance was on the bright sound that sometimes was harsh till I find that the ceramic headshell was/is the right match now this cartridge perform beautiful, something similar happen with the Nagaoka ( Jeweltone in Japan ), Shelter , Grace, Garrot , AKG and B&O but when were mounted in the right headshell/tonearm all them performs great.

Other things that you have to know: I use two different cooper headshell wires, both very neutral and with similar “ sound “ and I use three different phono cables, all three very neutral too with some differences on the sound performance but nothing that “ makes the difference “ on the quality sound of any of my cartridges, either MM or MC, btw I know extremely well those phono cables: Analysis Plus, Harmonic Technologies and Kimber Kable ( all three the silver models. ), finally and don’t less important is that those phono cables were wired in balanced way to take advantage of my Phonolinepreamp fully balanced design.

What do you note the first time you put your MM cartridge on the record?, well a total absence of noise/hum or the like that you have through your MC cartridges ( and that is not a cartridge problem but a Phonolinepreamp problem due to the low output of the MC cartridges. ), a dead silent black ( beautiful ) soundstage where appear the MUSIC performance, this experience alone is worth it.

The second and maybe the most important MM cartridge characteristic is that you hear/heard the MUSIC flow/run extremely “ easy “ with no distracting sound distortions/artifacts ( I can’t explain exactly this very important subject but it is wonderful ) even you can hear/heard “ sounds/notes “ that you never before heard it and you even don’t know exist on the recording: what a experience!!!!!!!!!!!

IMHO I think that the MUSIC run so easily through a MM cartridge due ( between other facts ) to its very high compliance characteristic on almost any MM cartridge.

This very high compliance permit ( between other things like be less sensitive to out-center hole records. ) to these cartridges stay always in contact with the groove and never loose that groove contact not even on the grooves that were recorded at very high velocity, something that a low/medium cartridge compliance can’t achieve, due to this low/medium compliance characteristic the MC cartridges loose ( time to time and depending of the recorded velocity ) groove contact ( minute extremely minute loose contact, but exist. ) and the quality sound performance suffer about and we can hear it, the same pass with the MC cartridges when are playing the inner grooves on a record instead the very high compliance MM cartridges because has better tracking drive perform better than the MC ones at inner record grooves and here too we can hear it.

Btw, some Agoners ask very worried ( on more than one Agon thread ) that its cartridge can’t track ( clean ) the cannons on the 1812 Telarc recording and usually the answers that different people posted were something like this: “””” don’t worry about other than that Telarc recording no other commercial recording comes recorded at that so high velocity, if you don’t have trouble with other of your LP’s then stay calm. “””””

Well, this standard answer have some “ sense “ but the people ( like me ) that already has/have the experience to hear/heard a MM or MC ( like the Ortofon MC 2000 or the Denon DS1, high compliance Mc cartridges. ) cartridge that pass easily the 1812 Telarc test can tell us that those cartridges make a huge difference in the quality sound reproduction of any “ normal “ recording, so it is more important that what we think to have a better cartridge tracking groove drive!!!!

There are many facts around the MM cartridge subject but till we try it in the right set-up it will be ( for some people ) difficult to understand “ those beauties “. Something that I admire on the MM cartridges is how ( almost all of them ) they handle the frequency extremes: the low bass with the right pitch/heft/tight/vivid with no colorations of the kind “ organic !!” that many non know-how people speak about, the highs neutral/open/transparent/airy believable like the live music, these frequency extremes handle make that the MUSIC flow in our minds to wake up our feelings/emotions that at “ the end of the day “ is all what a music lover is looking for.
These not means that these cartridges don’t shine on the midrange because they do too and they have very good soundstage but here is more system/room dependent.

Well we have a very good alternative on the ( very low price ) MM type cartridges to achieve that music target and I’m not saying that you change your MC cartridge for a MM one: NO, what I’m trying to tell you is that it is worth to have ( as many you can buy/find ) the MM type cartridges along your MC ones

I want to tell you that I can live happy with any of those MM cartridges and I’m not saying with this that all of them perform at the same quality level NO!! what I’m saying is that all of them are very good performers, all of them approach you nearest to the music.

If you ask me which one is the best I can tell you that this will be a very hard “ call “ an almost impossible to decide, I think that I can make a difference between the very good ones and the stellar ones where IMHO the next cartridges belongs to this group:

Audio Technica ATML 170 and 180 OCC, Grado The Amber Tribute, Grace Ruby, Garrot P77, Nagaoka MP-50 Super, B&O MMC2 and MMC20CL, AKG P8ES SuperNova, Reson Reca ,Astatic MF-100 and Stanton LZS 981.

There are other ones that are really near this group: ADC Astrion, Supex MF-100 MK2, Micro Acoustics MA630/830, Empire 750 LTD and 600LAC, Sonus Dimension 5, Astatic MF-200 and 300 and the Acutex 320III.

The other ones are very good too but less refined ones.
I try too ( owned or borrowed for a friend ) the Shure IV and VMR, Music maker 2-3 and Clearaudio Virtuoso/Maestro, from these I could recommended only the Clearaudios the Shure’s and Music Maker are almost mediocre ones performers.
I forgot I try to the B&O Soundsmith versions, well this cartridges are good but are different from the original B&O ( that I prefer. ) due that the Sounsmith ones use ruby cantilevers instead the original B&O sapphire ones that for what I tested sounds more natural and less hi-fi like the ruby ones.

What I learn other that the importance on the quality sound reproduction through MM type cartridges?, well that unfortunately the advance in the design looking for a better quality cartridge performers advance almost nothing either on MM and MC cartridges.

Yes, today we have different/advanced body cartridge materials, different cantilever build materials, different stylus shape/profile, different, different,,,,different, but the quality sound reproduction is almost the same with cartridges build 30+ years ago and this is a fact. The same occur with TT’s and tonearms. Is sad to speak in this way but it is what we have today. Please, I’m not saying that some cartridges designs don’t grow up because they did it, example: Koetsu they today Koetsu’s are better performers that the old ones but against other cartridges the Koetsu ones don’t advance and many old and today cartridges MM/MC beat them easily.

Where I think the audio industry grow-up for the better are in electronic audio items ( like the Phonolinepreamps ), speakers and room treatment, but this is only my HO.

I know that there are many things that I forgot and many other things that we have to think about but what you can read here is IMHO a good point to start.

Regards and enjoy the music.
Raul.
Ag insider logo xs@2xrauliruegas

Showing 50 responses by lewm

Decca has virtually no cantilever. Which is why the old heavy Deccas would beat the hell out of the LP groove. Compliance = 0. A hyperbole to be sure, but not far from reality.
Here is a nice explanation involving the tangency hypothesis that I found on DIYAudio. In this thought experiment, tangency and headshell offset angle are one and the same. But it seems to me that even if the headshell offset angle was set to zero, the stylus tip cannot be perfectly tangent to the groove walls at all points on the playing surface of an LP, because the stylus tip is describing an arc that is at an angle to the arc of the groove. Hence I invoke lack of tangency per se as the cause of SF.

"Imagine a flowing river. Now hang a paddle into it. Angle different to flow direction. The river's flowing water will exert friction and stream forces on the paddle. AS the flowing direction is not aligned parallel with the paddle's blade, stream force exert a momentum trying to rotate the paddle until its blade is aligned with the flowing direction. Then the momentum becomes zero and the only forces remaining are the friction forces trying to pull the paddle out of your hand.

So: the skating force's origin (in fact the SF is a momentum referenced to tonearm pivot) is exactly the same of the momentum caused by stream forces described above. "Flowing direction" is the groove tangent thru the stylus tip. As the tonearm has a headshell with an offset angle to minimize lateral tracking error and as the phono cartridge is aligned to that heasdshell, the groove tangent has a distance to the tonearm pivot. So a momentum develops turning the tonearm towards the spindle. Like the paddle in the river.
Dear Timeltel,
You wrote, and I comment:
"Two items related to the discussion, go to this link and click on "owners manual", the geometry of the tonearm is pictured on the last two pages and also gives two offset angles, one for the 12" and one for the 16" Sony arm. Hopefully it can be seen that the importance of offset is a matter of alignment and not the "offset" appearance of the headshell."

This kind of makes me say, "Duh!" Of course the offset angle is there in order to maximize the tonearm geometry or "alignment". What we/I am saying is that (additional) skating force is an unhappy consequence of offset angle. I thought we all agreed on this and the only area of controversy was my additional proposal that lack of tangency to the groove of a line drawn from stylus to pivot is an additional factor (because even if there is zero headshell offset angle, that line will still not always if ever be tangent to the groove).

"That a headshell appears to be out of congurence with the center-line of the arm and is largely the cause of skating needs to be dismissed." OK. Dismiss it for me in terms of the physics. I don't mean this to sound confrontational; I hold you in high esteem as a friend and source of information that I take to heart. I am willing to be wrong and to be educated. But many other sources do flatly maintain the importance of headshell offset angle in the generation of a skating force.

As regards the role of VTF. All other things being equal, which I realize is not the case, an increase in VTF should be accompanied by an increase in friction and therefore an increase in skating force. But if the stylus of an MC is typically riding at some level in the groove where less stylus drag is generated, perhaps that factor could dominate over the effect of VTF per se.

Dear Raul, You are too fickle for me to be unsettled by your claim of the superiority of the Astatic to the Grace. Did you compare them both in the same tonearm on your system in the last day or two, or are you going on your memory of the sound of the Ruby? Does it not also count that our systems and probably our preferences are miles apart? Actually, I have no basis at all to claim that the Grace is better than the Astatic, just that it's really really nice for me right now. I am not tempted.
Never mind. I am reading the Sony treatise on their bias compensator. Need to see where it leads.
Timeltel, I am with you on this. Lack of tangency to the groove is all that is needed to generate a skating force. I need to think more about the added or supplementary effect of headshell offset angle. But on many fora around the internet, skating is ascribed to headshell offset, and I was influenced by that because I had not thought it thru for myself. Further, while sitting at a sublime live jazz concert last night I came upon a proof that for our conventional pivoted tonearms the stylus tip is never parallel to the groove wall, based on the Pythagorean Theorem. Hence, there is always a skating force of varying magnitude. (I am finally remembering how to do vector algebra, which will allow me to consider the headshell offset angle, but I need to sit down with pencil and paper.)

Interestingly, for the RS-A1 tonearm, which specifies 21mm of stylus tip UNDERhang, the stylus is likely to be parallel to the groove wall at some point in tracing its arc across the LP. Thus canceling skating force.
Skating force is a centripetal force because the tonearm resists movement in the actual direction of the force vector that is generated by lack of tangency of the tonearm/pivot/stylus to the groove wall. That vector is actually changing in direction AND magnitude as the stylus goes from outer to inner groove and is never truly "centripetal, but only its centripetal component (component that is perpendicular to the tonearm/pivot/stylus line) is "expressed", because of the stiffness of the tonearm. Thus only the force vector that is along the arc defined by the location of the pivot and the tonearm effective length is in play = centripetal force = skating force. Besides this geometrical source of skating force, there are also the variables related to friction, which is affected both by stylus shape and groove modulations, both of which alter the magnitude of the skating force but not its direction. That's my story, and I'm sticking to it. I can prove it, if you want. (Without having completely read the Sony treatise, I have a feeling this is pretty much what they said using different words.) The headshell offset angle can figure into this only possibly by changing the angles involved.
Dear Fleib, I love you, but you have forced me to get even more pedantic than I have already been. There CANNOT be ANY points on the arc traversed by the stylus wherein the (pivoted) tonearm is perfectly tangent to the groove, and here is why:

When the tonearm/stylus is tangent to the groove it must also be perpendicular to the radius of the LP. Correct so far? When that condition pertains, then a line from the pivot to the spindle (the P2S distance) must also constitute the hypotenuse of a right-angle triangle. OK? When or if that is ever the case, then said right angle triangle must conform to the Pythagorean theorem: a-squared + b-squared = c-squared, where "a" is the tonearm effective length, "b" is the distance from the stylus tip to the spindle, and "c", the hypotenuse, is the P2S distance. Well, we already know that all conventional pivoted tonearms are installed such that there is stylus OVERHANG, which must mean that "b" in our equation is always greater than "c". Thus the Pythagorean Theorem can never be satisfied. Ergo, tangency never happens. Which is why we always have a skating force. I can go on to explain the direction of the vector of the skating force, if you like. But it's easier to do that with vector diagrams, which are not possible here.

Also, I say again, the term "centripetal force" is naught but a description of a particular kind of force. In a way, you are correct when you say that there is no centripetal force on a stylus. The force that is generated due to the geometry is actually always at an angle that points more or less to the left rear of the turntable starting at the stylus tip, not to the spindle. But the stylus cannot move in that direction due to the mechanical stiffness of the tonearm, so the force vector gets expressed in the only possible direction for the stylus to move, which is inward toward the spindle via rotation of the tonearm on its pivot.

Timeltel said it first in its simplest form: "Skating force is due to stylus overhang", or words to that effect. It took a few days to dawn on me why that is correct.
Dear Fleib, You wrote, "Regarding the theory behind AS: I really don't know if centripetal force is the primary cause."

Skating force IS a centripetal force. "Centripetal force" is just a descriptive term that tells us that the vector of the force is directed toward the center of a circular path of a body in motion. Centripetal force does not "cause" anything. What causes the (centripetal) skating force is the fact that conventional pivoted tonearms are never tangent to the groove wall. Because of that there is always a force vector generated that is in a direction determined by the angle between tangency and the actual angle of the tonearm wrt the groove. This force is per se not centripetal, but we only "see" its centripetal component because the mechanical stiffness of the tonearm translates the actual force vector (which is always changing in direction and magnitude) into one that IS unidirectional and is centripetal. (The tonearm only allows free rotation in one arc, directed toward the spindle, i.e., "center-seeking".)

As I see it, the skating force is a force over and above that which is exerted on the stylus tip by the grooves to guide it in a spiral toward the center of the LP. That force by itself would not induce the tonearm to skate. Anyway, that's what I am thinking at this point. The forces exerted by the groove wall would be present for any and all styli riding in any tonearm, even linear trackers. (I start from the fact that in an air-bearing linear tracker, that force is the only force acting on the stylus tip, yet we say that linear trackers do not induce a skating force.)
Headshell offset does allow for tangency at two points across the LP surface. Flieb said that, and I agree with that. It was my error not to include that in the analysis. My model would predict that at those two points, there is no skating force. My explanation was incomplete but not wrong per se. I should have said "a straight line from the pivot to the stylus tip" is side a in the Pythagorean Theorem model, and is never tangent to the groove. Dover, tangency would always occur at TWO points on the LP surface, if the cartridge is properly aligned according to any of the conventional algorithms. You can't do better than that.

In my scheme, the actual force generated due to friction between stylus and groove and the lack of tangency of the stylus tip to the groove (at all but two points on its arc across the LP), has a vector that is constantly changing in magnitude and direction, but the direction is always somewhere between the line drawn from the stylus tip to the spindle and a line drawn from the tonearm pivot to the stylus tip. The skate force vector is always directed away from the stylus (as you say) toward an ever-changing point within those two confines. However the stylus cannot move in that actual ever-changing direction, because the mechanical stiffness of the tonearm prevents it. Instead, the stylus moves or can move only toward the spindle, along its permitted arc, as determined by the location of the tonearm pivot. A lot of words, but precise language is necessary.

I think Timeltel (or you) was contending that this is not a true centripetal force, and I now agree. Its origin is not that of a true centripetal force as described in Newtonian mechanics. (Gravity holding a planet in orbit around the sun, for example.)
Fleib, The "basic vector", if you refer to the torque (i.e., angular force) of the turntable motor that is applied to the LP grooves, is indeed in the clockwise direction. But the force that causes skating is the friction between the stylus and the groove walls, which must always be in the exact opposite direction from the motor torque vector, i.e., anti-clockwise. The friction force opposes the motor force, IOW. The work done on the stylus tip by the motor via the groove interface is dissipated as heating of the groove walls.

I am going to bow out of discussing this subject further here, because it is probably boring to others, but if anyone wants to discuss it further via email, I am happy to do so.
Dear Nikola, It may comfort you to know that in the one course in Philosophy that I took in college, I had a very serious young Swiss professor who was very strong on Martin Buber (I and Thou) and Kant. I know that I read The Critique of Pure Practical Reason, and I wrote a paper on it which is still in my possession, somewhere. I remember more about Kierkegaard and Sartre and read them independent of course requirements, for years, because like many in my generation, I decided I was an Existentialist. I did not then realize that consciously acquired labels often lead to permanent ideologies. Thus, while I believe there is a skating force, at heart I don't give a damn.
Dear Nikola, By now you may already realize that the name of the actual person behind the eBay entity called "Foxtan" is Alex. It is just a coincidence that he and your favorite Dutch(?) cartridge repairer have the same first name. I believe Mike has been dealing with Foxtan/Alex, because that is where he bought the P100LE. I have done business with Foxtan, too, and I have no basis for complaint. So it would be of value if you could tell me/us specifically what problems you know about, as regards doing business with Foxtan. He finds and sells a lot of juicy vintage analog stuff that guys like us covet, e.g., tonearms, step-ups, and cartridges.
Dear Nikola, I must say I am completely stumped by your response. Apart from the fact that you did answer my only question by relating Halcro's experience with Foxtan, I don't understand why you impute to me any other motive for my post. I asked you a question about Foxtan, and you have answered it. There was no other intent on my part, except to say that the human being behind the Foxtan name is someone named "Alex". My errors were to say that your guy (in Germany, not Holland) is Alex when he is Axel. (This also begins to sound like Abbott and Costello.) Anyway, thanks for the information. It would seem that Halcro was angry, because he had to pay return shipping for his defective TT101 but that Foxtan did refund at least the initial cost. I think Henry was justified; Foxtan should have paid shipping. However, this incident would not deter me from doing business with Foxtan, perhaps with an advance agreement about what happens if the product needs to be returned.
Thanks, guys, for reminding me about Jim Howard. I think of him as a repairer of broken bearings, but you are quite right; he can probably do a re-wire. Ditto for the reference to Thomas Schick's photos of the FR64 disassembly. And thanks Nikola for reminding me that Dertonearm is very experienced with FR tonearms. I suppose I could take a chance and send the FR to Europe. The potential for customs abuse and long delays does scare me, however.

Nikola, My 64S does have silver wire inside, but I want to eliminate the DIN plug connector in the signal path. In fact, I am not too cowardly to do that much myself, come to think of it. But Dertonearm has been so emphatic in his praise of the Ikeda silver wire, I was thinking why not go ahead and re-wire the whole thing. (On the other hand, since FR = Ikeda, the "Ikeda silver wire" may be little different from that which is already inside my 64S. DT would know.)

As to Paypal, I agree. What good are they, if they cannot help one to recoup one's payment? In this case, the culprit was not from eBay; he advertised the tonearm on Craigslist. (Please don't laugh.) Possibly Paypal can do more if the seller is an eBay advertiser.
I guess Paypal in Australia and Europe is more proactive than the US version. About three years ago, I bought a Dynavector tonearm from someone in New York. The item was not only defective (collapsed horizontal bearing) but also missing several major parts. The seller was a true sociopath who lied to me for several weeks in the form of reassuring me that he was about to send or had sent the missing parts, etc. Finally, when I realized that I was in the hands of a psycho, I went to Paypal, they said they could not help me to recoup my money. But the guy on Paypal was kind enough to refer me to VISA. It was only via my VISA card (and because I had paid with VISA via Paypal) that I was able to recoup about half of what I had paid. Ever since then, I make sure to use my VISA when purchasing via Paypal.

While there is a lot of talk about competent cartridge repairers, does anyone know of a reliable and skilled person who can re-wire tonearms without damaging the bearing, preferably in the US? I would really like to re-wire at least two of my vintage tonearms (Kenwood L07J and FR64S), but even with my DIY bent, I am loathe to take on the job for myself.
Don, The Grace Ruby and the Grace F9E are different animals, so all I can say is that I am glad you are happy. If I luck into an Astatic, I will give one a try. But I am not depressed about not owning one.
AKG P8ES. Am I correct in thinking there is no consensus on this cartridge? Based on my reading, it seems there were a few who did not like it and obviously there are others who do. If the Grace Ruby was not so enchanting at the moment, I might have a listen to mine to see what I think. In any case, P8ES and P8ES super nova will both come next in my personal Odyssey.

The Owners Manual for the DV505 tonearm has me wondering about tail up or tail down use of the DV505. The Manual shows a diagram of how to set up the forward vertical bearing part of the arm, and anything but level with the main horizontal part of the arm is labeled with a big X across it. Perhaps there is some problem with this particular tonearm due to its unusual spatial separation of the horizontal and vertical bearings, wherein tail up and tail down use would cause some sort of unintended distortion. But it is not obvious to me why that would be.
Don, you are suggesting change the angle of the cartridge body without changing the angle of the headshell wrt the horizontal arm. Clever idea. I actually was so bold as to go tail up with some of the MMs for which pos VTA is recommended, and I detected no issues. But the putative warnings against doing that in the DV505 manual are powerful for an anal audiophile, nonetheless. (I say "putative", because it is also possible that they only wished to convey the notion that level is preferred to achieve proper VTA for most MCs. The translation of the text to English leaves a lot to be desired.)

I have the Grace Ruby set level to the horizontal arm and hear no reason to experiment further. Low and mid bass could be more powerful, but I am not sure that the phono stage itself is not the culprit in that regard. Pos VTA would be advantageous with the AKG, I think, because the cartridge body would be perilously close to the LP surface otherwise.
Mike, I would be very interested in your comparison of Ortofon M20FL Super to AKG P8ES, because I did evaluate the former one in my own system. It did not come up to the level of the Acutex LPM320 or the Grace Ruby (not to mention the Stanton 980LZS running in a different tonearm/turntable). But I made some very major changes to my downstream components since evaluating the Ortofon, so I need to be open-minded about revising my ranking.
There ARE things you can do with your clothes on, even at our age, that do transcend even the fun of MM (and don't forget MI) cartridges. You need a human partner, however.

Wish I could post a photo of my Sound Lab 845PXs. You could look at that huge panel and then imagine it being driven as a one-way speaker, with no crossover at all, albeit by two audio step-up transformers driven in parallel, by an OTL amplifier. It is truly my Holy Grail come to life.
Recipe for finding an Astatic MF200: Simmer one audiophile over a low flame for two months, until there is a new flavor of the month cartridge here, and the MF200 is in the dustbin of history. Meantime, look out for long-forgotten flavor of another month: MF100. Stay tuned for upcoming be all and end all, MF300.
Don, By using the phrase "flavor of the month" or similar, I for one do not mean to dismiss the particular cartridges that got that label. Most all of them that i have been able to sample are in fact superb. My point is that one can live happily with any one (or two?) of many of these cartridges, that while I believe they all sound subtly different from one another, more than one can be truly "great" or "exceptional". So it is not a tragedy not to own any one particular one of our collective favorites. I just bought a second Ruby from eBay, with a broken cantilever and no stylus; I intend to send it off for a ruby re-tip to see what effect that has, compared to a fully original one. Should I send it to SoundSmith or Axel? Should I stick to elliptical stylus or try a line contact type?

Meantime, I am tending to rank the Grace Ruby ahead of the Acutex LPM320. Cannot say where the Stanton 980LZS fits with respect to the Ruby.

Thanks, Dgob. The fact that your opinion differs so dramatically from Raul's and others is evidence that we all have very different systems and different tastes.
I bid 2 bucks above his minimum opening bid and thought for sure that I would never win it, but that was all I was willing to pay for a Ruby that needs a rebuild. To my surprise, no one topped my offer. I think I have the addiction under control if I am only spending a couple hundred bucks every 2 or 3 months. Plus I have at least a half dozen cartridges and a few tonearms that I am preparing to sell, if I ever overcome my inertia. (This is what I would tell my shrink if I had one and if he were a Freudian.)
Well, Nikola, you got me. I am guilty of all you say. But I don't own a Glanz cartridge and never heard one. And from my ~10 cartridges, I would probably keep six of them, not just the Grace Ruby. I believe Casanova would have said, "Love the one you're with". Compared to owning boats or collector cars or chasing women, it's a relatively cheap passion.
You bet it is, Nikola. Sadly, the wife is not a follower and will not accept quotes from Sartre or even Kierkegaard as an excuse.
I think it boils down to the fact that what you hear when listening to a record is the sum of a myriad of factors that govern the sound quality. And to make it more complex, those factors interact with each other in unpredictable ways. Therefore, the correlation between this or that cantilever material and sound quality may be understandably poor. By the way, not everyone thinks the Magic Diamond is so highly regarded. And I thought the TOTL Miyabi cartridges use Boron, but evidently I am wrong.
Hi Tom, I bought a second Grace Ruby that is really like new except for the small detail that its cantilever was wiped out along with the stylus. I intend to have it rebuilt, most likely by SoundSmith. As you may know, they offer a ruby cantilever/line contact stylus rebuild that looks to be the best choice for the Grace. Do you have any thoughts on the sonic effect of going to an LC from the stock elliptical one on an original Ruby? Thanks. Anyone else can chime it, too.
Dear Nikola, Did you listen to the Acutex LPM420? If not, perhaps you should open one up and give it a try. It is not a given that the opinions of others will govern your results. Raul got into this MM stuff by having an open mind and by disregarding the pronouncements of the audio establishment. This is the biggest lesson I learn from Raul. And so I recommend to ignore even his opinion in lieu of developing your own. If you have had a listen, then I would like to know what you thought about that cartridge. I haven't opened the box that mine came in, so far, but I only bought one.
Dear Citizen Steve, By the term "stylus holder", do you refer to the "stylus assembly", the entire element that comes out when one removes the stylus from the "body"? I found a similar strategy worked very well with my Stanton 980LZS. Apparently Stantons are notorious for having loose stylus assemblies. Mine was VERY loose. I took a very small rubber band and wrapped it around the stylus assembly/body so as to squeeze them firmly together. Man, does that cartridge sound great now. I think a lot of MMs suffer from this malady that is so easy to fix in a variety of ways. (But there's no going back from super glue.)

Dear Nikola, I understand exactly where you are coming from. I have not had 100% correspondence between Raul's opinions of cartridges and my own, after I audition ones that he has recommended. But his batting average is very high, I do admit. Nevertheless, those few instances of discordance are sufficient for me to realize I need to form my own independent opinion before taking the drastic step of selling one of these rarities. After all, Raul's system and mine are pretty much as far apart in concept as two "high end" systems can get. That alone justifies caution.
Dear Nandric, Yes, I think of our friend Raul as a GPI, while I walk through the forest of vintage cartridges. He tells us where we are.

Dear Raul, I take your point about distortions, but for me it is a distinction without a difference. I take it you are politely inferring that my system is inherently more distorting than yours. I find your arrogance on that subject to be a bit irritating but also interesting and mitigated by your other very fine qualities. I make no judgement about "better or worse" or "distortion", since I never heard your system. Nor have you heard mine. I was merely trying to say that two very different systems and two very different pairs of ears will very often result in different opinions. Actually, what is surprising is how close we all (not just you and me) come to consensus on any given cartridge.

Dear David, Like you, I thought about using glue, when I saw how loose was the stylus assembly on the Stanton, but feared that I would never be able to repair the cartridge, should the cantilever or stylus wear out or be damaged. Fortunately, the Stanton is built in such a way that a rubber band is easy to do. Most other cartridges are not amenable to that solution. Thanks for that additional idea. I wonder about using say one very tiny drop of one of those quickie epoxy glues; you might be able to break the glue line at some later date if repairs were needed. Yes, like Raul, I think this is an Achilles heel of MM and MI cartridges with replaceable styli.
Dear Dean, I guess some are tight and some are loose. There's a joke in there somewhere, but I am not trying to find it. Someone else sent me a long directive on how he actually does major surgery on Stantons to correct the loose fit. It involved removing the outer body of the cartridge from its inner workings and looked far too dangerous for me, Mr. Klutz, to try.

Mike, I don't really know what Raul means when he talks about distortions and especially about his unique ability to hear them and correct them.
Even if any two of us owned exactly the same gear, it would sound different in two different listening rooms. The effect of the listening space is huge. Then too there is the quality of the electricity from the wall, RF pollution, etc, etc.

I unashamedly admit that I have had a predilection for OTL tube amplifiers and ESL speakers for most of my audio lifetime. I accepted the shortcomings in order to have the benefits. Right now, thanks to modifications of my basic gear, I have never been happier or closer to my idea of perfection. That's the way anyone should feel, so I have no problem that Raul feels that way about his system. This is one area where one can be completely self-serving.
Dear Nandric, I tend to think you can trust Steve's (Vetterone's) judgement. He is a pro, and he says he has done it for many different MMs. But read his instruction carefully (I am saying this to myself as well as to you); just a tiny drop in a few places on the outside of the interface between the "stylus assembly" (OK, Emmanuel?) and the cartridge body. When finally the two must be parted for repair or replacement of the stylus/cantilever, a judicious use of a razor blade should permit disunion.
Dear Don,
IMO, neither Audiogon nor Paypal will help you with this problem, so your best bet is to stick with the seller and hope that eventually he will see the light. You do quote him as having written: "I don't know how I can help you but I'm willing to do anything you want it." This is simple; what you want is your money back or some reasonable fraction thereof or for him to pay Axel.

By the way, Audiogon has a new owner who is apparently not so much of an empathetic audiophile as was the original one. Paypal is just worthless, period, in my previous experience of trying to recover funds.
Dear Raul,
I just read about the major earthquake you have suffered in Mexico City. I hope that you and your family and friends are all OK.
Dear Nikola, Have you read "Spies of the Balkans", by the American novelist Alan Furst. A great WWII spy story, one of many written by Furst, but it shows that Balkans have guile, if not always a sense of humor. Of course, the Nazis were not funny, either.
Dear Nikola, I did not realize my attempt at camaraderie left you bleeding a la Caesar. No insult was intended. Since I am a doctor, I will send a band-aid and a lovely nurse to install it. Please give me your Paypal address.

On a more serious note, it is Mexicans who rightly and fairly count themselves as Mexicans. They live in a separate and sovereign country to our south. And if Spanish ever becomes the predominant language in the US, it will have been related to an influx of new citizens from many different countries in Central and South America and from Puerto Rico and Cuba, as well as from Mexico, but it won't happen in our lifetimes.

Don, If you call someone "illegitimate", it is usually a commentary on the marital status of their parents. "Illegal" is more accurate and less condescending and insulting. I would imagine that in the south central US, the illegal and legal Spanish-speaking immigrants are primarily Mexican, but that is not the case here on the Eastern seaboard and in the Northeast. Most of the Spanish-speaking people in my area are from South and Central America, Puerto Rico (all of them "legal"), and Cuba. Most of these people are honest and work very hard each day. But do practice your Serbian.
Long before I encountered this thread, my first inkling that there may be some merit in these "old" MM cartridges was the result of listening to a Pickering cartridge at the home of a friend who was already open-minded enough, sans the input of Raul, to have discovered MMs on his own. I think the Pickering was called "TLS40", or something like that. He bought it NOS from an eBay vendor for peanuts (meaning very little money, Nikola). It's made of cheap plastic, but the sound was shockingly good. So the lesson I have since learned is that cost is often, if not usually, not proportional to performance. And of course any decent MM or MI cartridge is dramatically more cost-effective than a similarly good MC, maybe notwithstanding the Denon DL103 or 103R.

As to the issue of glue. I think it's a good idea even if the fit seems snug, because it will force the cartridge body and the stylus assembly to dissipate energy in a more linear fashion; the two elements will vibrate as a unit, rather than as disparate and dissimilar parts. For a Stanton or upper level Pickering, the rubber band solution is, IMHO, even better, because the tight-fitting rubber band will further dampen vibrations of the body/stylus. This is all theory, of course.
I will be selling those rubber bands suitable for "cartridge dampening". They will be made of special 100-year-old rubber extracted from the first automobile tires, only. They are then impregnated with silver, gold, pixie dust, and antivibratorium (a newly derived compound that uses "quantum physics"), and then cryo'd (good guess by someone else). I cannot possibly produce these for less than $100 each, so the retail will have to be $500. Each one will be numbered and signed by me. Now taking orders.
Ct, I am just like that guy in the video, only without the 'fro.

Re customs abuse. I have found that the border between the US and Canada is a much more problematic one across which to send packages than any other. I get capacitors from Russia in better shape and in less time than it takes to get capacitors from Parts Conexion in Canada. And once I endured a lengthy nightmare trying to receive a Lenco from Canada, where the pkg was erroneously sent to North Dakota and then BACK to the sender in Canada, before finally it arrived here with some damage. I bought a cartridge from Raul a few years ago that arrived OK, but I can imagine that there is even more paranoia and incompetence surrounding US and Mexico customs interactions. But it does seem improbable that Customs was responsible for the ball of tape caper.
Dear Albert,
Based on previous exchanges with Raul, it seems I like the 980LZS much more than he does. In my system and IMO, it is much more than a "very good performer". If you are dissatisfied with yours in any way, I would be happy to take it off your hands. Also, don't laugh, I found the performance was improved by tightly wrapping it with a rubber band, so as to firm up the junction between stylus assembly and body and to dampen resonance. I run mine straight into the MP1 preamp, using either 1000R or 47K load. It does need gain to shine.
Dear Albert, I would be very careful if using a SUT with the 980 to be sure that you don't end up with a load impedance that is too low for it to work properly. (I am now forgetting what Stanton recommends.) But I think these low output MMs present a kind of paradox; they like to see a high-ish load impedance but put out low voltage and therefore would be difficult to mate with a SUT. My Atma-sphere MP1 of course has more than enough gain for any MC or LOMM without using a SUT, so the issue does not arise for me, nor for Raul with his 3160.
Albert, I did a search to find the specs of the 980LZS. Apparently the internal resistance is only 3 ohms, which makes it suitable to drive even a 100R load resistor, and in fact I may have tried that with good results, now I think about it. (My 980LZS is sitting idle at the moment because I am re-wiring the tonearm on which it usually mounts.) The low output (0.3 mV) and the low internal resistance both suggest that the inductance will be more like that of an MC cartridge than that of a typical MM cartridge, so I am guessing you would actually be OK using a SUT, notwithstanding arguments for and against using SUTs. I have never even owned a SUT, so my opinion on that score is meaningless.
By the way, Raul, what on earth prevents you from revealing the identity of the LOMC that has you so excited? Do you think naming it would cause a stock market crash? We are mature enough to deal with the information without serious consequences to our mental health.
Dear Fleib, I am not going to say you are categorically "wrong" in some of what you wrote above, but just to say that my set of facts about the 980LZS are different from yours. First, my 980LZS came with an OEM D98S stylus, which is much more of a rare bird than a D81S stylus. The latter I can find on my Stanton 880 cartridge, I think. But on the other hand, my information agrees with you on the subject of identity with the Pickering XSV7500. I was told by someone knowledgeable here (maybe even you) that the styli on the 980LZS and on the XSV7500 were identical, which was what led me to buy the latter stylus when I earlier got the chance to do that, since an OEM and NOS D98S stylus is pretty much unobtainium. (Now 3 people will say they have one lying around.) What say you to that? Thx.

Dear Don, It would be OK, as far as I am concerned, to bring us up to date on the outcome of your dispute, when you feel it's time. Your recent silence on the subject led me to hope that all finally went well.
Dear Montepilot,
Thanks for your careful description of your experience. To continue in Halcro's line of thinking, what linestage (if any), what amplifiers, and what speakers? For that matter, what turntable? But I guess the point is that if you can hear the differences you describe among cartridges, the downstream equipment is not getting in the way of your perceptions. I heard the Puritas at the 2010 RMAF, in Steve Dobbins' room, and it was clear to me that it is very fine, indeed, in a Reed tonearm on his Beat turntable. Another that interested me, and still does, is the Soundsmith Sussuro. Also, Miyajima stereo and mono.
Montepilot, Thanks for your further response. You have a very nice system that is obviously very capable of reproducing the fine detail of which you speak. On my way home from work today, I was thinking like Banquo. I was wondering, could you tell whether it was white rice or brown rice or wild rice, bouncing on the drum skin? And like Banquo I was questioning whether I care about detail retrieval. But I do care. I think of my system as an instrument for playing LPs as accurately as possible. After that, I can choose the "flavors" for myself. Fact is, I don't feel deprived of inner detail whilst listening to the Grace Ruby or the Stanton 980LZS. When I compare them to a "good" MC, the Ortofon MC7500, I don't feel that the Orto retrieves significantly more detail. And the former two cartridges are more "musical". This was exactly the remark of a close friend who listened to the two cartridge types in my system two days ago.

As for MM phono stages, it is my observation that there are some great bargains to be had among used and even vintage phono stages, some of which feature adjustable loading for MMs. I was able to pick up a Silvaweld SWH550 phono stage about a year ago by winning an auction on eBay. I use it for MM, only, although it does have an optional input for MC as well. Once I changed its output coupling caps, it is a dream. Nandric, you might be happy with a tube type MM-only phono.
I don't suppose you've read Nikola's posts wherein he has censured me for having a pair of Beveridge 2SWs in my basement that I am not using. (I want to rebuild the amplifiers first.)

Personally, I consider the language available to us to describe the sounds that emanate from audio systems to be wholly inadequate and always colored by subjectivity, except for the most general statements. So I usually don't bother to use the terms you dislike or even the ones you prefer. If you indeed do not wish to be offensive, then don't be condescending. For example, I have never in my life been to a rock concert. My sister and wife were both at Woodstock, however. (They did not know each other at the time.) For another example, a speaker with a 13 to 100K response could as well sound horrible as it could sound "good".