JBL 2226H - Outside Ground Plane Measurements

I was just messing around with a small build (Wayne 4Pi Speakers) and wanted to take measurements of the JBL 2226H before proceeding.

I dropped the 2226H in an enclosure I had laying around and took it outside for some ground plane measurements. The enclosure was about 18.5" wide and 24" tall (just about).

I was pretty impressed with the response and thought I share my results.

Nice smooth mid-range with minimal cone break up. This is raw response, no EQ, no baffle step circuitry, etc.

Now I can't remember if the measurement below was taken with the cabinet tilted slight down (so the woofer faces the mic) or with the cabinet facing forward. Probably the latter since I don't see a rising response - but nonetheless, still very impressed with its smooth mid range quality.

Very Nice!

That response curve could easily be used by JBL in their marketing efforts ( so, big pat on the back ).

Did you follow any of the advice/protocols that resulted from that thread ( over at diyAudio ) on making ground-plane measurements ?

I'd love to hear some more details ( surface plane type > or smoothness , distance to mic ).

:)

Quote:

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Originally Posted by Earl K

Very Nice!

That response curve could easily be used by JBL in their marketing efforts ( so, big pat on the back ).

Did you follow any of the advice/protocols that resulted from that thread ( over at diyAudio ) on making ground-plane measurements ?

I'd love to hear some more details ( surface plane type > or smoothness , distance to mic ).

:)

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Earl,

Great tips in the link you provided. The surface was a concrete driveway, with the nearest distance to grass approximately 6 feet.

Mic was about 6 to 7 feet away cabinet. There was neighborhood noise, but the measurements were not impacted after I took them at a little louder volume.

The mic was MiniDSP Umik. Soundcard was Focusrite Scarlete Solo. 1/24th Smoothing

The mics rear side is a little thicker than the front, so I tilted the mic down so the front is touching the concrete.

My main objective was to get an indication of how reasonably close the technique suggested by Jeff Bagby (RIP) LINK matches outside ground plane measurements.

See attached graph. Blue is with the method suggested by Mr. Bagby. Red is outside ground plane.

I think they match reasonably well, especially considering they were taken with two different measurement setups (my indoor setup is Dayton - CSL Calibrated Mic, using ARTA, and Focusrite 2i2), and different mic distances.

There is always a little bit of user error when merging far-field with near-field (baffle/diffraction adjusted), and scaling port vs near-field woofer. ------ but still ----- pretty close.

As silly as it may sound, I want to try my first go at open baffle speakers. Wanted to get an idea of how the 2226H measure - knowing full well the responsive in an OB setting will be drastically different.

I plan on experimenting with the 2226H on the bottom + the Heil AMT-1 on the top. The combo would allow me to cross at 1.1Khz or so (likely 4th order).

I'll be using a 10mh+ inductor in series with the 2226H - which will obviously destroy sensitivity, but this is just to try OB with the parts I have on hand.

The high value inductor approach is being borrowed from what I saw on Troels G Website, in his OB-11 built - he took a similar approach with the Eminence Deltalite II 2515

The specs on the 2226H are not too dissimilar to the Eminence 2515 - so I will give it a go over the next couple weeks. Wish me luck :).

Quote:

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Originally Posted by dkalsi

As silly as it may sound, I want to try my first go at open baffle speakers. Wanted to get an idea of how the 2226H measure - knowing full well the responsive in an OB setting will be drastically different.
.

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I wonder if 2226 not as useful OB or vented...?

Ron sends...