Audio Nirvana Super 12 Cast Frame measured T/S

[Michael Chua]

The Super 12 just came in for testing. Results of T/S are below. Measured with LMS, Delta Mass (20g added weight). Loaded in a 60L Sealed Box. Bass response is adequate for most music.

Regards
Mike

[Scottmoose]

V. useful. Thanks. Any chance any of you moderating types could move this to the FR section of the forum, as that would seem the better place for it?

[loninappleton]

Super 12 clones have been created for the Audio Nirvana. I hope some enterprising designer will use these params for a new treatment -- something to get the build excitement going.

For caveman audio, a tweak with a tweeter ala the original super 12 would be of interest.

I've thought about the Audio Nirvana Super 12 as a floor stander for a while now.

Original Hammer Super 12 tweaks page:

Single Driver Website

[Michael Chua]

Originally posted by loninappleton

I've thought about the Audio Nirvana Super 12 as a floor stander for a while now.

I think its best to put that on hold for a while. Initial listening indicates the Super 12 is not balanced. Too much upper mids and highs. Quite a bit of peaking too.

Will do some FR sweeps to see where the problems are.

[loninappleton]

Certainly no rush. I seldom get past the blue sky stage.

Even so a comparison with Hammer for better or worse would appreciated. In my early days reading at full range driver forum I always thought the Hammers were the nuts. The site creator Mr. Melhuish does too. He has built and features variations on the Hammer build but that is mostly in materials and does not veer from the recommended design.

[FullRangeMan]

Originally Posted by Michael Chua

The Super 12 just came in for testing. Results of T/S are below. Measured with LMS, Delta Mass (20g added weight). Loaded in a 60L Sealed Box. Bass response is adequate for most music.
Regards
Mike

Iam newbee in testing, Why do you add 20 grams mass to the cone??
Gustavo

P.S.: Maybe this 60 litres box is small, do you know the max cubic volume for this SUPER12CF ?

[MJK]

Originally Posted by FullRangeMan

I am newbee in testing, why do you add 20 grams mass to the cone??

When you are testing a driver to determine the complete set of T/S parameters, you need to make two impedance curves.

The first impedance curve is the driver alone from which you can derive the Re, Lvc, fs, Qes, Qms, and Qts parameters.

You also need to estimate the driver cone's Sd using a ruler, typically it is the calculated projected area using the diameter taken at about 1/2 of the surround width.

Then you need to make a second impedance curve after either adding mass (typically small masses, I use US five cent coins because they are 5 gms each) or adding stiffness (mount in a small closed box of known volume) to shift the driver's fs by about 25%. Then based on the frequency shift, and the known added mass or stiffness, you can now calculate BL and Vas. This is done automatically by most testing software. Or it can be done with pencil and paper if you are measuring a driver the old fashioned way with an O-scope, signal generator, frequency counter, and volt meter.

Most books on speaker building will show you how to do these measurements. D'Appolito's book Testing Loudspeakers will tell you both how to make the measurements and theoretically why you are making these two measurements.

[FullRangeMan]

Originally Posted by MJK

When you are testing a driver to determine the complete set of T/S parameters, you need to make two impedance curves.

Thanks Mr.Martin for this full explanation. These tests are more complex than I thought.

Dear Mr.Michael Chua: Please keeps us informed about your SUPER12CF tests.
Thanks boys, Gustavo

[MJK]

Originally Posted by FullRangeMan

These tests are more complex than I thought.

Automated testing software/hardware readily available to DIYers make these measurements easy, accurate, and quick. Woofer Tester, Praxis, ARTA, Sound Easy are just a few good examples. You don't need any special training, just follow the directions to get good results.

[FullRangeMan]

Originally Posted by MJK

Automated testing software/hardware readily available to DIYers make these measurements easy, accurate, and quick. Woofer Tester, Praxis, ARTA, Sound Easy are just a few good examples. You don't need any special training, just follow the directions to get good results.

Nice, thanks for these test software. Do you think this Nirvana Super12CF is a good fullrange for a bass reflex no filter box??
Gustavo