it's just a testing method laid out by spec. I picture this as any other IEC standard, military standard, industrial standard, etc. They don't own the rights to the test methods. Manufacturers are encouraged to perform this testing... all it is a test method with the means of standardizing data provided to the consumer.I will dig in to it a little more. However, that are a lot of companies using it... and I can't see them paying a huge royalty for publishing if they buy the program.
at some point, we should try to chat on the phone about the testing. I don't want to do anything you're doing and I'm sure you don't want to do anything I'm doing. I'll be doing some things differently and in those cases I may still do my own (ie: compression testing) unless you've had a chance to change your method. If nothing else, we can share what we get privately just for a sanity check case. It'd be a lot easier to chat on the phone, though, I'm sure. If/when you get some time, feel free to give me a call.Hey Erin, Sonnie and I talked this afternoon and as I mentioned to him I just wanted to cover our bases. Ed Mullen mentioned in an email to me that we had to use the software developed by Don Keele specifically to comply with the standard. However; after the information you posted and Sonnie mentioned it was obvious that was really more of a preference/suggestion by Ed than a requirement.
Good stuff, I'm excited to get going on this. I just received several more subs and would like to run those tests this week and since I still have the other subs that were tested I wouldn't mind updating those with additional measurements.
This test is not trivial, but it will be possible to add it to REW. I'll try to get it added by year end. The tone burst lasts for 6.5 cycles, not 6.5 seconds, so (for example) at 40Hz it would last 162.5 milliseconds. The captured signal (with capture synchronised to the burst) then needs to be analysed to measure the peak SPL at the test frequency and the various harmonic levels, and limits for the various harmonics need to be applied to establish the max SPL value for the tested frequency. If the test is performed indoors the captured signal also needs to be windowed to gate out reflections and a room correction factor should be applied, which has to be determined empirically (e.g. by comparison with outdoor measurements).