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Posted by Frank Angel (Member # 248) on 01-30-2002, 01:19 AM:
In THX's packet which they sent me when I requested their specs for cinema sound systems, they have a ton of specifications for everything from noise from air conditioning ducts to adjacent theatre bleed-through, but nowhere can I find a specification as to the sound pressure level a system needs to produce in order to qualify for THX certification. Are they just assuming the Dolby standard? Seems the SPL attainable before clipping and available headroom would be essential specifications to any sound system design. They are doing a redesign of our theatre and I would like to tell the design engineers that we want them to meet or exceed THX specs if at all possible. Can't do that if THX doesn't publish specs for SPL.
Posted by John Walsh (Member # 168) on 01-30-2002, 08:54 AM:
Some THX spec's relay on other spec's (like Dolby).
It's like saying "Our spec is that you install the equipment according to the manufacturers instructions, or to SMPTE standards.
Posted by Gordon McLeod (Member # 33) on 01-30-2002, 09:47 AM:
The SPL spec is dependent on what you install
If it was to say be a optical only facility it is different to what would a digital or a mag facility
Posted by Rory Burke (Member # 512) on 01-30-2002, 09:18 PM:
The THX spec is SMPTE's spec per room volume/size and usage of analog digital etc etc....It is not a secret. Essentially the THX design will be capable of handling anything per yor apecified purpose so no need to worry about exceding as their Criteria<SMPTE's> is quite adequate. Good luck with your project and dont worry to much about the details as THX will not let you down in that department!Rory
Posted by Frank Angel (Member # 248) on 01-31-2002, 01:01 PM:
Thanks guys; that's what I assumed; I just thought it was odd that THX didn't include SPL and frequency response specs given how detailed all the other specs were that they included in their packet. Unfortunately, all the monies that were earmarked for the renovation project have been put on hold because of the huge budgetary changes caused in NYC by 9/11. I think it will eventually get put back on the table, but later rather than sooner.