“Omni” vs “Passive cardioid”

This will be the last post on subs for now (I do have one more idea but that’s gonna take some time before I can do the measurements).

Within my companies inventory I have Meyer Sound 900LFC’s which is a “omni” sub and Fulcrum Acoustic CS121’s which is a passive cardioid sub.

After doing the screen captures on sub arrays (Gradient End Fired A mix between Gradient and End Fired End Fired CSA ) I wanted to know the difference between the 900LFC and the CS121. This post is by no means a lab test. I’m just playing with some cool gear.

The Measurement points I used where at +/- 1mt 2mt 4mt 8mt and 16mt. This would mean that between each measurement point there would be a 6dB difference due to the old “Inverse Square Law” (each doubling of the difference -6dB).

The doubling of the distance can be clearly seen in the screen shots below here:

First the magnitude respons on the 900LFC at 1-2-4-8-16mt.

2nd the magnitude respons on the CS121 at 1-2-4-8-16mt:

The 900LFC was driven via a Apex Intelli-X2 analogue in (-20dB from Smaart’s generator) out at 0dB and the CS121 via Dante (also -20dB from Smaart’s generator) straight to the Powersoft (X8/Dante) output.

Here are the screen shots on the 1mt measurement position:

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Here are the screen shots on the 2mt measurement position:

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Here are the screen shots on the 4mt measurement position:

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Here are the screen shots on the 8mt measurement position:

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Here are the screen shots on the 16mt measurement position:

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The 900LFC front and back magnitude respons at 16mt:

At the 16mt measurement point the levels start to match sort of (a little offset between front and back but this difference will level out even more at for example 32mt).

The CS121 front and back magnitude respons at 16mt:

Both subs perform very well only the CS121 has about 10dB of level difference from front to back.

you can download the transfer data here:

TRF DATA CS121 VS 900LFC

Enjoy……