Hello, everyone,
I know that by the “nature of the beast” the inside tracks of an LP have more distortion. Any tips on how to get a cleaner recording or how to process some of this out? I am recording through a Pioneer turntable and equalizer/amp, out the 3.5mm headset connection, into my sound card, capturing with Audacity.
I wasn’t sure if I should post this here or in “Audio Processing”- I guess it depends on what tips you offer (grin).
Thanks very much!
Regan
http://www.discomusic.com/forums/showthread.php/2654-Why-does-the-last-track-of-a-lp-sound-distorded
I suppose you could use Audacity’s “analyze” feature to look at the spectrum of the first track on the album
then use audacity’s equalizer on the last track so it’s spectrum (approximately) matches the first, (the treble boost required will make any hiss worse though ).
As you correctly observe Regan it’s down to the physics and the geometry …
ASIDE: There did used to be some expensive TTs that compensated for this by having a horizontal arm along the radius of the LP and the cart tracked along it mainting alignment.
The best you can probably do is to ensure that your cartidge, headshell and arm are all set up and aligned properly - some of them come with protractors (usually cardboard) to get the arm and headshell horzontal alignment right. You can align the cart in the verical plane by placing a small mirror on the TT mat and (very gently) lowering the cart/stylus onto it - this enables you yo observe and modify the alignment.
The big question is: can your ears actually hear more distortion when playing the inner LP tracks? If not then there’s no need to worry.
I’ve used fairly good kit for many years and it’s not something that’s ever troubled audio appreciation of my LPs. 
WC
There are two issues here.
The linear velocity at the inner groove is lower than at the outer groove. Thus the waves are “bunched up” in the inner groove compared to the outer groove. This should not matter a whit unless one is getting down to the “grain” of the vinyl. The wave was accurately cut into the groove by the cutting machine. The stylus doesn’t know or care what the linear velocity of the groove is - it simply reproduces what is in the groove.
In the thread cited by PGA, someone who seems to think they’re an expert says; “As the groove gets closer to the center of the record, the actual velocity decreases, and you have much less space to squeeze the same amount of sound. The resulting grainy, distorted effect is called “mistracking”.” This is nonsense. He is mixing up two different effects - the supposed higher tracking error of standard (versus linear) tone arms at the inner grooves, and the supposed distortion caused by the lower linear velocity at the inner grooves.
Actually, there is only one groove and the linear velocity is slowly and steadily decreasing as the stylus travels from the outside to the inside of the LP. At what point does this mythical “inner groove distortion due to lower linear velocity” effect become noticeable?
Many standard tone arms have higher tracking error at the inner grooves. By tracking error we are referring to how far the horizontal axis of the cartridge is off from being exactly tangential to the groove when measured at the stylus point. For a well designed and set up tone arm zero tracking error occurs in two places on the LP. Everywhere else there is tracking error. The curve will have one maximum, plus whatever tracking error exists at the end points (the outer and inner grooves - yes, there is tracking error at the outer groove!). The curve can be optimized in a number of ways, including having lower tracking error in the inner groove than in the outer groove.
http://www.stereophile.com/content/arc-angles-optimizing-tonearm-geometry-page-5
So I dispute the claim that “the inside tracks of an LP have more distortion”. I’ve encountered many an LP that has higher distortion on the inner grooves because it has been played many many times using a poorly designed or set up tone arm that had high tracking error at the inner diameter and slowly ground up the groove. When the LP was pristine this distortion would not have been present in the groove, but may have been heard - even on first play - if the tone arm was not set up properly.
– Bill
Hmm, lots to think on here, guys, and I appreciate the input.
I do indeed have some LPs where the distortion on the inner tracks compared to the outer ones is, in fact, noticeable to my “naked” ear- enough so that I can pick them out when playing the music “shuffled”. I had believed that the difference had to do with the smaller radius of the track, and slower linear speed, making it harder to keep the needle tracking correctly and at the same time having to cram more “sounds”/ information into less linear movement as the track neared the center- the track getting more “crowded” at the same time it was getting more “crooked”, to simplify my impression.
Regardless, I am about halfway through my LP collection, and I am stuck with using the same old Pioneer turntable I bought in the mid-80s with its P-mount cartridge. I have replaced the stylus, but it appears otherwise I am pretty much stuck mechanically with what I have. I cannot believe what a decent turntable, by itself, costs these days!
Ultimately, without the Audacity and Click Repair programs, and the generous assistance I have received on this board, I would not get the chance to listen to my LPs while out driving or working. So even if they sound a little “off” at times, I am still miles ahead of not being able to hear them at all!
I really do appreciate each of you taking the time to educate me!
Take care,
Regan
The Shure SME tonearm has ropes, pulleys and weights to compensate for tracking errors.
http://www.analogue-classics.com/html/sme_3009___3012.html
I have a 3009.
The linear arms worked OK, but they tended to have motor noise unless they were very carefully built and maintained usually not worth the bother. The ones with the internal springs tended to have limited correction for tracking errors.
Koz
Actually, the weight on a thread is for anti-skating correction. And that’s another issue that may contribute to playback distortion. Cheap turntables don’t have any anti-skating correction. Slightly better is a spring set by a dial. Better is a weight on a string (hung over the correct point on the notched arm according to tracking force). The Thorens TD160 uses a magnetic anti-skating adjustment (no friction, no spring - don’t know if it is better or worse than weight-on-a-string).
– Bill
I can tell you the ropes and pulleys are a pain if you have to move the turntable. I recently got a new cartridge and had to go through the whole alignment thing again. I went back into the archive file cabinet to get the setup instructions. “If the cartridge weighs between three and four ounces, adjust…”
Koz
“between three and four onces…” 
That’s one heck of a cartridge. What sort of turntable is it, a war-time Russian military model? Do you then need to tighten the six 1/4" A/F retaining bolts?
You should see the one on my old early 1950’s Bal Ami jukebox (now in my son’s ownership) -rather than playing the 45’s it carved them 
Peter