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Practicality of reversing frequency response curve of phono cartridge / stylus

Burning question regarding phono cartridges and wondering how much this has been explored: 

How practical would it be to measure a phono cartridge's frequency response with a test record and then correct it with a digital signal processor to be ruler-flat, much like Genelec's GLM system does with a room? Does anyone offer a product that would do this? It seems that rather than spend thousands on a fancy cartridge, one could get by with an average cartridge and correct it with some rather simple processing (?)

My future plans are to use a CEDAR Cambridge processing system to archive the best examples I can find of early jazz music, and I'm forced by the nature of the records and the cartridges available to use a Shure V-15 VX with aftermarket 78-specific stylii, so I'm thinking it might be possible to correct for some of the imperfections of the cartridge if I have a baseline.

 

mke246
russ69's avatar
russ69
3,360 posts
 

Sorry, I learned this decades ago. You can't make a piece of electronic gear do what it can't do. Frequency correction isn't going to make an 18 inch woofer into a tweeter if you get my drift. Same thing for a phono cartridge. There are electromechanical limitations. 

solypsa's avatar
solypsa
462 posts
 

You could use DSP for your record curve ( which you need to adjust to a number of settings for old mono and 78 anyway ) and then tweak eq to suit yourself based on some test record recording passes. 

 

Get a good mic preamp that you can load at 47k -100k with say 30-50db gain into ADC into DAW with EQ and hit record :)

 

Seems like there could be better MM that could be fitted with a 78 stylus.

 

mijostyn's avatar
mijostyn
8,258 posts
 

VERY EASY! I have all the equipment now to do that. It would be the frequency response of the cartridge/ tonearm/ Phonostage and I would need to get a test record with a sine sweep, but correcting it is easy. I can change frequency response at 1 Hz intervals with a resolution of 0.1 dB.  The processor is 64 bit floating point running at 192 kHz. It also performs room control and bass management. You could also store different curves for different cartridges. The Trinnov Amethyst does all of this and I believe the Anthem STR will also but with lower resolution. Having said all that good phono cartridges are relatively flat. In comparison to speakers in rooms they could be considered dead flat. Unless you are really anal and only listen on headphones there are way more important fish to fry.

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