Problem with Perpetual P1-A.


I bought the whole perpetual package used on audiogon half a year ago, and it came with speaker correction, (I don't know what speakers it was programed for, and that isn't my concern right now). The problem it has always had ONLY when speaker correction is selected is that it causes a ringing through the tweeter with every bass note. the p3a alone does not do this so it is coming from the p1A and, again, only when speaker correction is selected. I don't see my speakers as being a problem becuase I output everything into my headphones and heard the same ringing. I use a coax input to the p1a and have not been able to try a balanced digital cable input because I don't have that type of transport. I use the I2s cable between the p1 and p3 and trying a balanced cable between them did not solve the problem. i think i've had a coax between the two and it didn't go away. the i2s should work anyway.
I can enjoy the perpetual equipment with resolution enhancement on, but the speaker correction does something special which I really like and often listen to it despite the ringing. Still, that ringing is really annoying and I usually end up switching back and forth. The gear does not have any mods as far as I know.
Anybody who knows these units or is expert in digital equipment in general might know what's going on.
Perpetual has a forum on their site, but I thought I'd check here first.
nola_powerman
Your SOCS is for a specific speaker. Using it for a speaker, or headphones, other that what it was designed for will cause frequency and phase changes that will most likely degrade the sonic performance of they system.

If you have the single curve SOCS, there were known problems with the algorithm that caused a ringing on heavy bass passages. PT modified thier SOCS code to implement a system with 9 correction curves. This allowed several variations on the corrections that could be applied. A side benefit of the 9-curve system was that the ringing was significantly reduced however, not eliminated.

PT is currently in the final beta testing of a fully rewritten P1-A software SOCS package and have stated that this will be availabe to current SOCS owners which was a $400 option. You should contact them for details.

Bottom line is that your version of the SOCS software has known problems and there is nothing that you can do about it at this time.
The speaker correction is SPECIFIC for a particular speaker and it is unlikely that it is for yours. Given that, it is possible that (1) the correction is working correctly in trying to correct the unknown speaker but add that 'ping' incorrectly for your speaker or (2) the correction is faulty. I'll bet that, if you gave your S/N to PT, they could tell you what speakers the correction is tailored for.

Either way, it is incompatible, so why use it?

Kal
Thanks... I always wondered what the deal was and never found answers through all the searches I've done on forum posts like this one.
I purchased the package for its upsampling capability, and with this being my first dac, I have relied on reviews and other member posts to justify my purchase. I thought if the speaker correction helped it would be a bonus, and after a lot of listening, I believe the speaker correction is mostly doing more good than harm to the signal.
I'm sure if programmed for the right speakers, it would be even better. Still, it would sure be nice if they could get rid of the ping completely. I'm curious if there is a short answer to how that ping is created from a bass note.
The ping is always noticable on material with a major bass component, but some material doesn't have that, or has enough other things going on to drown it out. Other than the ping, I just want to add what I think about the sound based on having the wrong speaker software. Despite what incorrect phase, frequency, etc.. modifications are occuring, I like the liquid wall of sound the SOCS creates. The localazation of sound directly from the speakers is less evident with my speaker correction on. Usually, even with that annoying ping, it is more listenable than with just resolution enhancement. Nevertheless, I always end up getting off my seat to switch it around just hear what it would sound like the other way, and sometimes I even use the p3a alone just for a change of pace.

It takes a tough ear to try and decipher the other differences,and I wish it came with a remote so I could switch it faster without having to get up. Another thing is I can't figure out what effect I should be hearing when I hit that absolute phase button on top.

I've been intersted in having the modright mods, and I'd consider getting the correct and updated software for my speakers, as long as I know I won't upgrade my speakers, or maybe there is another product that will give me similar results. I'll be content with it for a while and continue to switch the setting back and forth a lot, but eventually I'll get around to upgrading or replacing it. I'll be happy with it for quite a while, pings and all.