Audio CD-R’s are an extremely common media type and not that much more expensive since the AHRA royalty consists of only 3% of the cost of the Audio CD-R ($0.45 for a 50-spindle costing $15).
All currently produced Audio CD-R’s are physically identical to their regular data CD-R counterparts not subject to the AHRA fee, with exception of the SCMS bit and therefore will function the same when written to at low speeds. That is not to say that they will work well but clearly the manufacturers believe these CD-R’s are at least acceptable enough for low-speed recording to be certified and sold for that specific purpose.
The truth is that as long as we are talking CLV based writing strategies, there is going to be very little benefit in writing at an obscenely low speed. What does matter is the write strategy used, which when using modern computer drives is going to be optimized for higher writing speeds, 8x and 16x in my experience provide the best quality with current production Phthalocyanine media (CMC Magnetics, Ritek etc). Avoid CAV based strategies (24x and higher).
But since your goal is to make these discs work in your Playstation 1, even a perfectly written modern disc will not be sufficient. I likewise own vintage PS1’s and PS2’s as well as CD players from decades ago that have serious issues reading modern CD-R’s. The solution has been to use high-reflectivity (aka long strategy = cyanine, azo etc) media. I have found that the disc quality makes little difference for this purpose, since even the lowest quality Super Azo discs made by MBI in 2011, that come from the factory with such “features” like real holes in the middle of the reflective layer, beginning signs of oxidation and dye defects as well as horrendous quality scans still are recognized and play just fine in those picky players and are recognized faster than P-Cyanine media in others. So for compatibility, high reflectivity is King, not write speeds or even write quality. Unfortunately this means you have to change your media type, since there isn’t much you can do to polish a turd, so to speak, with your aliexpress sourced junk media.
If my subjective experience does not convince you enough, then I present to you actual test results done by an assemblergames.com user (topic link) who connected a multimeter and an oscilloscope to the laser diode drive circuit (APC type in this case) of the PS1 console and obtained the following figures:
Condition DMM Scope (p-p)
No Disc 580mV * About zero.
PSX CD 587mV 1.05V
HK Silver 587mV 0.95V
Audio CD 587mV 1.00V
Crap CD-R 587mV 0.70V
T-Y CD-R 587mV 1.00V
Azo CD-R 587mV 0.95V
He further clarified that the “Crap CD-R” in this test was a Phthalocyanine CD-R made by CMC Magnetics and branded Sony.
As you can see from these results, the P-Cyanine discs produce a significanly weaker voltage output which translates to lower precision reading, which means more errors and less chance of data being readable. The Taiyo Yuden and Mitsubishi Azo discs had values comparable to the pressed discs.
This supports my conclusion and experience that you need long strategy CD-R media to improve compatibility with most older, picky readers rather than worrying about getting the best write quality with P-Cyanine discs. Sorry if this post was a bit technical, if you have further questions I’ll try to answer them.