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Discussion Starter #23
cool stuff! that may actually save us some trouble as we can simply point to that set for CEA2010 compliance specs. good find!
 

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Discussion Starter #24
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.
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.

As far as a CEA2010 test software; that'd be news to me.


You can't use just a single tone because the tone has to be shaped. This site has them in mp3 format (which should be just fine)
http://www.brentbutterworth.com/tech
 

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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.
 

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Discussion Starter #27
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.
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. :)

256 466 3054

*hopes no one hacks the site and gets my number! lol!
 

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Lol, you should post it as 'For a good response call'. I already have it in my phone if you would rather delete it. I just left you a message as I am fairly open tonight setting up for the GTG I am hosting tomorrow. Too many subs!

 

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Thatsa lotta subbies there.

Here is what John says about the tone burst:

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).
 

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I decided to go ahead and implement a CEA burst option in the REW generator as an interim measure, a beta version that includes this can be downloaded from CEA-2010 beta. This can be used with the REW RTA, which should be set up with FFT Length 65536 if running at 44.1k or 48k, or 131072 if running at 88.2k or 96k, in all cases with Rectangular window - the generator has a checkbox to loop the burst to make testing and capturing the results easier. Note that there are a lot of other changes in that build, several are works in progress and the help files have not been updated yet.
 

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Discussion Starter #32
Awesome, John. Thanks.

Do you think you could implement a weighted curve like is done in the example pdf's I linked? For no other reason than it would be easier for us to look at the results and know. Otherwise, we'll just have to do some math. Not a huge deal. Would just be a nice feature if w had a curve. Edited because I had a brain toot. lol.
 

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The bells and whistles will have to wait until the end of the year, but in the meantime you could create a set of dummy measurement text files for the distortion limit profiles of the 6 CEA frequencies, import those into REW and use the SPL offset feature in the All SPL graph to shift them up and down to match the peak of the RTA captures. Fiddly, but doable.
 

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Discussion Starter #34
Yea... I figured I might have to import my own curve.

I'll have to play around with this. I use the Klippel for most of my measurements but may use REW for this. Nothing against REW... but it's just what I use. For some things I'll have to use REW (in the house measurements for subjective correlation) , though. I think once I do a few tests and try to do the cea2010 mapping it'll give me a better idea of which way would be easier to get the results I need.

Again, thanks for taking the time to do this for us.
 

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Man we had a blast today with all of those subs and the FV15HP Brian sent with Mike. Wish it was close enough for you to make Erin, you would have enjoyed it and could have offered a wealth of info for the guys.
 

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The GTG I went to a few weeks back had an FV15HP as well, and I have to say it was mighty impressive. It's huge, relative to most other 15" subs I've seen, but the depth and output were very solid.
 

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Discussion Starter #37
Wish I could, too, man. Do you have a thread discussing the meet? I'd love to see it and some pics. :)

Hope you guys had a blast!


I used to put on 2 meets a year at my old house but haven't in the last year. Hopefully when we finish our house I'll start back up again. There's nothing like getting together with a bunch of buddies and hanging out. The last GTG I had, 36 people showed up. I had a dude fly his own plane up from Miami! :eek:

I compete in car audio so I get to hang out with my buds a decent bit that way... but the environment of a GTG is so much more fun. Maybe one day I can make it out your way... or you guys can make it out mine. :)
 
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