What is the fidelity of the inner groove LP tracks?

Discussion in 'Audio Hardware' started by 12" 45rpm, Jan 23, 2018.

  1. 12" 45rpm

    12" 45rpm Forum Resident Thread Starter

    Location:
    New York City
    As we all know, the fidelity of LPs decreases as the needle gets closer to the center. I am curious how "bad" is the inner groove fidelity? I would reckon the outer grooves sound like master tapes, the middle grooves sound like cassette tape and inner grooves just sound plain terrible.. I own very few LPs that have hi-fidelity from inner groove tracks. My turntable is properly setup so that's not the issue.
     
  2. EdogawaRampo

    EdogawaRampo Forum Resident

    Not nearly. Depending on the cart and accuracy of the setup, you might not notice much or any difference at all. The cart and precision in the alignment can and do make a HUGE difference in my experience.
     
  3. missan

    missan Forum Resident

    Location:
    Stockholm
    The fidelity will vary between records, and also rather much between different needle cuts. Normally not as much as You propose though. But the outer grooves can sound noticeably better than inner grooves, but then the loudness will also be higher at outer grooves.
     
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  4. Morbius

    Morbius Forum Resident

    Location:
    Brookline, MA
    To second what EdogawaRampo said you shouldn't notice any change at all. What ever tracking differences there are and with everything set up properly should go completely unnoticed.
     
  5. Just Walking

    Just Walking Well-Known Member

    Location:
    Abingdon UK
    If your tracking is set right (with the correct null points, usually at 66 and 121 mm for a 9" arm with Baerwald alignment) the harmonic distortion is at a maximum of 0.5% at the inner, middle and outer grooves, and less than that everywhere else.

    The only other playback factor is the shape (and condition) of your stylus. In *principle* elliptical and other similar line profiles should fit the inner groove modulations better than a spherical stylus. However, I use a spherical stylus (Denon DL103/SME IV/Garrard 401) and I cannot discern any reduction in playback quality at the inner grooves.

    Things outside the scope of playback are the mastering quality in the studio. However good your playback system is, it can only extract what was pressed into the vinyl in the first place.

    I'm puzzled why there is the opinion that playback is louder at the outer grooves and by implication quieter at the inner grooves. Not so in my experience - if there is a reference which shows that to be the case I would be interested to read it.
     
  6. missan

    missan Forum Resident

    Location:
    Stockholm
    Inner grooves are the Achille`s heel of record playback. It´s not so that outer grooves are especially louder than inner grooves normally, but they intrinsically can be. The alignment distortion is only one part of the total distortion that aren´t favoring inner grooves.
     
  7. Chris Schoen

    Chris Schoen Forum Resident

    Location:
    Maryland, U.S.A.
    Never had any "inner groove" problems. Perhaps my AT440 and DL110 carts overcome these issues.
     
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  8. ggergm

    ggergm red right returning

    Location:
    Minnesota
    Agreed in that the inner grooves are where you'll hear the most problems with tracking the LP. For years I've used "Tennessee Jed" off of the Grateful Dead's Europe '72 album as a turntable set-up test. It's the last track on Side 4. Garcia's guitar solo is at the end of the song and is panned hard left. Tracking it well is a tough task. If my turntable tracks his solo, usually everything on my turntable is set up correctly.

    There are three things going against good tracking of the inner grooves:
    1. Depending on the geometry you pick for setting up your cartridge, the tracking angle error can be high. In other words, the needle, which in a perfect world is always tangent to the groove, can be the most off tangency. It might be as off as much on the outermost groove, too, but the next two factors tend to make life better for the stylus on the outer grooves and hardest on the inner ones.
    2. The skating force drawing the needle toward the center of the record is the highest on the inner grooves. A person can argue that of all the forces acting upon a stylus, skating force is the least important but it is still there. It can make tracking inner grooves tough.
    3. There is more information packed into the inner grooves. It takes 1.8 seconds for a record to turn one revolution. If an inner groove is 2½" from the center of the record, and the outer groove is 5½" away from the center, an inner groove is 15¾" long and an outer groove is 34½" long (remember 2πR?). The same 1.8 seconds of music has to fit into each groove. It's packed more tightly into the inner groove. The wiggles in the vinyl are coming fast and furious on the inner grooves compared to the outer ones.
    All this said, the posters upthread are right. If things are set up correctly, your stylus should track the inner grooves just fine. I can get my turntable to track Garcia's guitar solo perfectly. It's just harder to do than if it was elsewhere on the record.
     
    Last edited: Jan 24, 2018
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  9. thegage

    thegage Forum Currency Nerd

    I almost always notice difference in sound of the inner grooves if they are cut significantly close to the label. I wouldn't characterize the sound as "terrible." I more prefer the oft-used term "pinched," as it gives a clue to how the cutter handles the inner grooves. This is different from the sound of mis-tracking caused by improper setup, or a worn cartridge/LP. Interesting discussion here:

    Q. Why is vinyl not the best medium? |

    John K.
     
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  10. c-eling

    c-eling Forum Resident

    Having done hundreds of transfers-
    I've seen ----- levels being consistent and >>--- levels starting off at max and gradually sloping down, probably to grab the listeners attention.
    I haven't noticed any drop in quality on the last track per side.
    Why Worry sounds just as good as So Far Away
     
  11. Ken Clark

    Ken Clark Forum Resident

    Location:
    Chicago Suburbs
    I have a Zu Denon DL-103 which I carefully aligned on my P25 and most all of my records sounds the same beginning to end, and not just the "audiophile" pressings, which are less than 10% of my vinyl collection. You may need to check your cartridge installation and alignment.
     
  12. 12" 45rpm

    12" 45rpm Forum Resident Thread Starter

    Location:
    New York City
    It is intersting that most people are saying they hear minimal difference in inner vs. outer groove. I had my table professionaly setup a year ago. The guy was very knowledgeable and spent an hour with it. Since then I have probably put on 500 to 1000 hours of use on the needle. So maybe the needle is starting to show signs of wear ? It is a pro-ject 1.2 with Grado Red.
     
  13. toddrhodes

    toddrhodes Forum Resident

    Location:
    South Bend, IN
    Having been through multiple carts, alignments, and LPs, I can say that for me, inner groove "infidelity" is unavoidable on some records. I've had the worst luck with the metal genre and it's certainly not across the board, but I think the density of sound, the length of the side, and the relative lack of attention to detail are all contributors. It does help, a little, to move to a Stevensen alignment, so that's what I typically roll with.

    But, my overwhelming conclusion is that, properly aligned and setup, there is no, or at worst only subtle difference in fidelity from outer to inner groove when considering my entire collection. But, queue up a few "problem children" LPs in a row and suddenly it becomes a battle of wills between neurosis and the understanding that everything related to analog playback is a compromise and the best you can do is strike the best one your skills , the tools you have, and the hardware you own allow you to.
     
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  14. 4011021

    4011021 Forum Resident

    Location:
    Brazil
    I only experience inner groove problems when the record is dirty and the needle keeps collecting dust on its way to the end of the record. It happened yesterday. I thought, "wow, IGD, I finally heard it", then I checked the stylus.
     
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  15. Morbius

    Morbius Forum Resident

    Location:
    Brookline, MA
    You should try a Hunt EDA Mk6 just before you put the needle down. I always do just to avoid that little glob of dust at the end of the record.
     
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  16. Drewan77

    Drewan77 Forum Resident

    Location:
    UK/USA
    I find that LPs with cartridges aligned precisely & cleaned vinyl, fidelity shows no apparent change throughout both sides. (2 Regas, a Technics SL1200G - Dr Feickert / Baerwald).
     
  17. chervokas

    chervokas Forum Resident

    Differences should be minimal from outer groove to inner groove, if you have some tight inner grooves cut very close to the label with very load program material, you're more likely to have audible tracking distortion in those side-end situations than on the outer grooves, especially if you have very loud, and/or very bassy source material cut close to the center of the record. You'll probably likely notice it on things like symphony records where there are big movement ending tutti crescendos packed at the end of side. Of course there will be considerable differences not only from record to record but especially from cart to cart and from stylus profile to stylus profile. But if you're hearing continual noticeable sonic degradation of some sort as the record plays -- and I'm not sure I get your master tape/cassette analogy "fidelity" in terms of your description of what you're hearing. Are you hearing raspy distortion on peaks? Or something else? If the center of your records sound like cassette tapes, you're definitely not getting the best out of your records -- you probably have an alignment and or stylus wear issue.
     
    Last edited: Jan 24, 2018
  18. harby

    harby Forum Resident

    Location:
    Portland, OR, USA
    #1 and #2 are functions of your imperfect turntable. However #3 is a real thing, even when the lathe cuts tangentially to the groove and when a linear tracking turntable is used (without the need for antiskate and without the tracking angle error.)

    I post a comparison of the start vs the end of a 45 here, played back on a linear tracker: Are 45RPM 12" Records Superior in SQ To 45RPM 7" Records?

    Even at the higher rotation speed of a 45, the quality suffers near the end. This may be because the mastering engineer put down all the level they could and tapered off the volume nearer the end, or even that no special care was done to ride the EQ for the groove location. Most LPs don't have the same material at the start and at the end for you to compare, in fact, they are often arranged with quieter tracks near the end of a side.

    I would expect that serious mastering, where we now can plan the whole disc digitally, includes automatic EQ compensation and permissible envelope of the cutting position. There are some factors that still would need further technological advancement unlikely to happen, such as a variable cutting angle head that can compensate for the different amount of deflection and springback of the disc material being temporarily deformed as it spins at variable speeds under the force of the cutting head.
     
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  19. PhilBiker

    PhilBiker sh.tv member number 666

    Location:
    Northern VA, USA
    Kudos for an excellent post!!!!! Thanks for taking the time to write this. This is why I love my linear trackers - they minimize this kind of tomfoolery.
     
  20. missan

    missan Forum Resident

    Location:
    Stockholm
    If we look at reasonable max modulation angle at most outer groove, it can have a level at 1kHz of about 12dB. For the same modulation angle at most inner groove it´s 4dB.
    So it´s possible, at least, to have a 8dB louder sound at 1kHz at outer groove. All of this isn´t normally used.
     
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  21. Just Walking

    Just Walking Well-Known Member

    Location:
    Abingdon UK
    This is an excellent paper on anti-skating by Shure's James Kogen in 1967. They made a cartridge with a pivot, which would only adopt the straight ahead position if anti-skate was set perfectly. They looked at skating force as a function of tracking weight for spherical and elliptical stylii, with distance from the record label, and with modulation level. It is however critically dependent on correct alignment (they plot as a function of overhang)

    Anyway, the key point is that skating force is only weakly dependent on distance from the label, as it is with modulation level for an elliptical stylus (less so with a spherical).

    There is significant variability between one pressing and another, and the possible causes of this are discussed.

    http://www.audiomods.co.uk/papers/kogen_skatingforce.PDF
     
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  22. Larry I

    Larry I Forum Resident

    Location:
    Washington, D.C.
    Most records, particularly modern records do not have recorded material that runs close to the inner label. That is most likely to happen with classical records because the individual movements/tracks can be quite long. Even with demanding classical music (long tracks and crescendi coming near the end of the movement), a good cartridge that is properly aligned in a good tonearm should be able to play without obvious mis-tracking. I don't hear obvious degradation in sound with records playing the inner groove in my setup.

    I have heard inner groove distortion in sub-optimal setups. A friend of mine bought an entry level table when he was first getting into records. Almost immediately, he bought an Ortofon PW cartridge which I helped with mounting on the cheap table. Although the alignment was done really carefully using proper tools (Feikert protractor, two digital scales set to measure at the level of the record, Fozgometer to set azimuth) and a custom-made counterweight was crafted by another friend to properly balance the arm, there was a slight bit of inner groove distortion on highly modulated passages of music. The arm simply could not handle the amount of vibrational energy fed into the arm by the cartridge; a better quality, well damped arm was needed. Medium to low compliance cartridges, like the PW, demand very rigid and well damped arms. Fortunately for this friend (and his rapidly growing collection), a much better setup (EMT arm/table) quickly replaced this table.
     
  23. McLover

    McLover Forum Resident

    Location:
    East TN
    Also, so does the quality of the mastering engineer. And also how the album is assembled (the arrangement of the tracks). Put the loudest, highest energy tracks on the beginnings of sides, put the quieter tracks and ballads towards the end of the sides, keep it to 17-18 minutes a side. This improves the quality of the final record you get. If you have a really long album, going to 2 LP discs is much better, and gives you better sound.
     
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  24. Morbius

    Morbius Forum Resident

    Location:
    Brookline, MA
    I have more than a few records that run well over 25 minutes per side and they still do cut close to the label on modern records, they may be reissues but they do. If all is handled well during the mastering process sound quality suffers very little except in cases where there is 30 minutes or more of stereo program on that side. Then you become very aware of the compression they used to make the cut possible. Also I was told by an ex mastering engineer who frequents Vinyl Engine that they give little consideration to where and what order the tracks go relative to energy level, louder or softer and their placement on a side of a record. I think they give more consideration to timing.
     
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  25. Higlander

    Higlander Well-Known Member

    Location:
    Florida, Central
    Think the Op is referring to the effective speed of the vinyl moving at a smaller radius.
    That has nothing to do with cart/stylus, but is a more built in aspect of vinyl "Rules", that must be respected, or you will have issues.

    They are effectively limitations in how loud and what fidelity is retained as the diameter gets smaller and smaller.
    This is more based on correct mastering and not putting loud songs near the label or making the last song too loud.

    IGD is something else, but somewhat inter-related, but able to be mostly alleviated with stylus shape etc.
     
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