My custom Funk Audio (Funky Waves) DBD12 Subwoofers - Page 3

Originally Posted by blindbug

The bracing in these things looks great! Wish I had a workshop to pull something like this off... actually, I wish I had the woodworking skills to pull this off!

Originally Posted by pbc

That's what I used to think, but doing a decent job even with little expertise isn't has hard as you would think!

Great looking speakers DB ... did Nathan provide any sweeps without the 90hz pass? Curious how these drivers perform beyond 100hz?

Originally Posted by Eternal Velocity

I would get the Dayton EMM-6 over the Behringer.

Originally Posted by Eternal Velocity

Accuracy.

WMAX had this to say:

http://techtalk.parts-express.com/sh...68&postcount=5

Originally Posted by riverwolf

Herb at Cross-Spectrum has confirmed P-E's included mic specific calibration file for the EMM-6 is accurate for on axis duty if you're only measuring 20-20K. Of course, he'll gladly provide you with 5-25K and 45°/90° calibrations for an additional fee. Since you're specifically interested in measuring your subs, you might want to research how much typical correction the EMM-6 needs below 20Hz in making your decision...I don't remember off the top of my head. The 90° curve is pretty much a necessity if you want see what Audyssey/YPAO/MCACC is doing in your room, IMO.

The Behringer doesn't include any calibration data. A little Google-fu should turn up pages overlaying multiple ECM8000 measurements samples. Their (lack of) consistency should convince you not to trust the generic calibration files available online.

-Brent

Originally Posted by penngray

A calibrated ECM 8000 is just as accurate. Wmax, opinion not with standing because any product can fail. I have the calibrated ECM 8000 and have used it for many years now without issue (so have 100s of other DIYers).

Granted, the Dayton EMM-6 is fine too and a cheaper choice.




FWIW, no one is buying an uncalibrated ECM-8000 mic so there should not even be a discussion about generic calibration files. There is definitely an assumption that when purchasing any Mic that there is a professional calibration that comes with it.

Originally Posted by penngray

You can buy a non-calibrated ECM8000 but that isnt really needed. You need to search to find a source for ECM8000 calibrated mics. There are a couple of popular ones, I just don't have the links.

Anyways, from previous discussions just get the EMM-6 for $46 from PE. There is absolutely nothing you are going to be doing that requires this much discussion or thought over either choices so pick the lower cost solution.

Originally Posted by Eternal Velocity

Key word calibrated. The dayton mic comes at the very least with a parts express calibration file. Albeit not down to 5hz.

You must have misread that party of his post, that's exactly what he was saying. He used to be a big advocate of the behringer mics.

I was under the impression OP was looking at an uncalibrated ECM8000, hence why I recommend the dayton mic. I'm sure a calibrated unit would be a great choice, especially if accuracy down to 5hz is necessary, but I don't know if I really would pay the extra cost for measuring infrasonics beyond "there" and "not there"

Originally Posted by riverwolf

No reason to buy another mic later, unless you're looking to upgrade to Earthworks or B&K quality. Herb (Cross Spectrum), or any other calibration service, can do an extended calibration on pretty much any mic. Herb has just taken the step of stocking EMM-6 and ECM8000 mics so that he can ship them out with various levels of extended calibration instead of someone first having to buy from vendor A, ship it to him, and then ship it back. So, if you prefer not to pay the extra $40-50 now for an extended calibration services, you can ship out your EMM-6/ECM8000 in the future and get an extended cal done...albeit by spending slightly more than if you'd simply purchased the mic w/cal together in the first place.

-Brent

Originally Posted by riverwolf

As I stated earlier, Herb is Cross-Spectrum Labs. He also goes by "anechoic" here, HTGuide, TechTalk, and HTS...probably other places as well.

To summarize the most popular options again.

DIY a Panasonic capsule based mic: Needs calibration if you want absolute response numbers. Otherwise, like an RS SPL meter, it can still be used to show before/after changes simply by analyzing relative changes. Accuracy for subwoofer measurements down to 20Hz is probably pretty good without a cal, but the capsules are subject to some manufacturing variability and the user's ability to build/provide a suitable preamp will also be a factor.

ECM8000: Available from any number of vendors. Doesn't include a calibration file. Generic cal files are available on the internet, but of questionable value since a number of folks have compiled enough data to show a decent amount of unit to unit variation.

EMM-6: P-E includes a 20-20kHz on axis (0°) cal file unique to each mic, S/N traceable. Herb, and likely other cal services, will provide more data points (higher resolution) across that range. After doing hundreds of these mics, Herb has recommended the P-E cal file as good enough if you only want to measure on axis from 20-20kHz. IIRC, the biggest variation is usually in the 12-15kHz area, where Herb's extra resolution will provide more accuracy and a smoother curve.

Purchase a calibrated ECM8000/EMM-6: Herb/Cross-Spectrum will sell you either and has options for different levels of calibration. I linked you to his EMM-6 page in an earlier post. Penn suggested there are other retailers selling calibrated ECM8000s, but I'm not aware of who he's referring to. Herb's cheapest cal option is on axis from 5-25Khz. He also has options for 45°/90° axis, polar response, and sensitivity. Full boat cal for an EMM-6 is $99 to a US address; the ECM8000 runs about $10 more. He will ship internationally.

Buy the mic of your choice from the vendor of your choice and send it out for calibration. Cross-Spectrum and Kim Giardin (sp?) are probably the most well known to the DIY community. Google should turn up others.

-Brent