Help in determining sq criteria
Dec 22, 2011 at 11:38 AM Post #16 of 24
Quote:
Also, clearly I should perform an ABX test. Tricky to do, but I could enlist the help of a friend to switch out the headphones for me.  I'll be using 2 sets of headphones, ksc75 and grado sr225.


Why would you need help to switch headphones? You don't need to ABX headphones, you need to ABX the sources. ABXing headphones is easy since you can tell which one is which by how they feel on your ear, and ABXing them wouldn't prove anything about playaways vs. lossless.
 
Dec 22, 2011 at 11:54 AM Post #17 of 24


Quote:
Why would you need help to switch headphones? You don't need to ABX headphones, you need to ABX the sources. ABXing headphones is easy since you can tell which one is which by how they feel on your ear, and ABXing them wouldn't prove anything about playaways vs. lossless.



The idea is that the general public library patron isn't going to be hooking their playaways up to grado sr225s, but I will use the sr225s to best judge the sq of the various media. 
 
I will also run duplicate tests with the ksc75, which is closer to what I expect most playaway users will listen to their playaways with. 
 
Thus I can comment on what an everyday user might experience (via ksc75) as well as the sq of of the media itself (hopefully somewhat objectively) through "better" headphones.  Because clearly, the vast majority of library patrons don't own $200 headphones!  I wish I hadn't tossed my ibuds, otherwise I would have used them instead of the ksc75.
 
 
 
Dec 22, 2011 at 12:25 PM Post #19 of 24


Quote:
Okay, but you don't need help switching the headphones. You need help switching what they're plugged into.



Yes, yes, thats what I meant.
 
Interestingly, the media rep at Findaway is refusing to release the information to me that I requested regading what the maximum bit rate they compress their files at, how much a 1 gb unit costs, and what bit rate criteria they use to qualify a file "HD Audio".  I'll have to assume 128kbps is the max.
 
Dec 22, 2011 at 12:34 PM Post #20 of 24
If you know how much storage space there is and how many seconds it holds, finding bitrate is pretty trivial. Try to ask them about that stuff instead if you don't know it.
 
Dec 22, 2011 at 12:40 PM Post #21 of 24


Quote:
If you know how much storage space there is and how many seconds it holds, finding bitrate is pretty trivial. Try to ask them about that stuff instead if you don't know it.



Yeah, turns out the website I found isn't "theirs" and they are neither confirming or denying its accuracy.  I guess I'm going to have to not go through their media rep and just speak to an ordinary sales rep and ask the questions you suggest.
 
thank you
 
 
Dec 22, 2011 at 12:40 PM Post #22 of 24
Also, RMAA measures the analog performance of devices through their normal outputs. As I said before, it is a very crude tool, so I would advise against making any comparisons between vaguely similar figures (eg 0.06% THD and 0.04%) and just look for big deviations from what would be expected.
 
Dec 22, 2011 at 12:49 PM Post #23 of 24


Quote:
Also, RMAA measures the analog performance of devices through their normal outputs. As I said before, it is a very crude tool, so I would advise against making any comparisons between vaguely similar figures (eg 0.06% THD and 0.04%) and just look for big deviations from what would be expected.



Thank you!
 
 
Dec 22, 2011 at 1:20 PM Post #24 of 24


Quote:
If you know how much storage space there is and how many seconds it holds, finding bitrate is pretty trivial. Try to ask them about that stuff instead if you don't know it.



All I could get from the company is that the HD players can hold [size=11pt]128MB, 256MB, 512MG, or 1GB[/size] worth of memory, and that the playaway can hold "up to 60 hours of audio content".   All other info relevant to my project is proprietary.
 
Is there a way to roughly determine bitrate from that info?  *edit*  found a calculator online (http://patcoola.coolastudios.com/?p=183)
 
Thanks for the help everyone, this is very helpful groundwork!  
 
Incidentally I've found that unfortunately RMAA won't work since the playaway is pre-loaded with content and I can't input a test signal for processing and analysis.
 
Think I got everything I need to move forward.  Thank you most sincerely to ALL posters.  This has been a very educational thread and will help me significantly with my report!
-Jason
 
 

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