I've been wanting to do some upgrades to my turntable for a while, so I did some googling and decided to try an aftermarket turntable mat. Your average turntable comes with a standard rubber mat which is designed to absorb vibrations from the turntable while also providing a removable and easily cleanable surface on which to play your records.
After a bit of research, I quickly decided on a Herbie's Way Excellent II mat due to relatively high praise and good reviews. Let's read a bit about what makes this turntable mat so great—from Herbie's own website:
Made with finely textured, open-cell silicone foam, this mat has unsurpassed vibration-absorbing characteristics and no resonant qualities to discolor the music. Records are thoroughly decoupled from unwanted platter vibration.
A black elastomer "donut" on top of the white foam base reduces vinyl/stylus feedback and eliminates lateral slippage. Unique qualities allow the vinyl to "give" slightly, microscopically, to stylus contact, allowing the record groove to be tracked smoothly and accurately.
Wowzers. I never usually buy into this audiophile snake oil stuff, but the physics at least made a little bit of sense to me—a foam mat would naturally absorb more vibrations than a rigid rubber one would, right? It certainly wouldn't hurt to find out, at least not as bad as some other audiophile products.
Many of the reviews for this product describe improvements such as "a broader sense of space", or "enhanced imaging depth", or "more dynamics and punch". Not a single person, however, mentioned performing a blind test to decide if it was objectively better. So that's what I did.
Below are two audio samples taken from the same record. The first was recorded using original rubber mat that shipped with my turntable and the second one was recorded using the Way Excellent II mat.
For the test, I used foobar2000's ABX Comparator component to compare the two FLAC files and listened with a fairly decent pair of headphones (ATH-A500). The only processing I did was to normalize the volume in order to take care of any slight variances between the two files, as louder music is sometimes perceived as "better", even if the difference in volume is very small.
After doing 10 blind trials, the results came in... I got 4/10 correct; it told me that there was an 82.8% chance that I was guessing. I have to admit that I couldn't tell the difference between the two recordings at all. I've come to the conclusion that you probably won't gain any significant increase in quality (or decrease in noise) by using an aftermarket turntable mat. The difference between the two recordings—if any—is so small that you will never notice any improvements during normal listening conditions.
For those curious, the equipment I used to perform this test is a vintage 1978 JVC QL-A7 turntable, fitted with a Shure M97xE cartridge. My phono pre-amp is an Audio Technica AT-PEQ3 which gets fed into my soundcard, an Asus Xonar DS.