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Testing Jordan Watts Module DATS v3

This afternoon i spent some time putting the Jordan Watts modules through the Dayton Audio DATS V3, the results where interesting…

Following up on last months post on the JW Gemini Speakers
My friend Henry is designing Horns for them, i dont really have the experience in Full range drivers to make the most out of these, especialy something so rare and unique!
I turned to the only man i trust for the job HARWOOD ACOUSTICS I told him i could provide the TS from the DATS , from my research i remembered had them listed and it would be interesting to compare.

DATS v3 Results

You can see from the results the TS parameters vary somewhat, theres a resonance deviation of 8.5% and 11% in M(ms) i feel like these drivers should work fine in a stereo setup the varience of properties should be neglible.

I would be reluctant to say these are 100% healthy, The variation is quite high and by todays standards would fail, they dont seem to be 100% in line with Marks results either.
Running a “Rub & Buzz” test on the DATS software confirmed the drivers to be within acceptable tolerance it may just be an age thing but something isnt right.

Examining the graphs closer you can learn alot not only about a drivers performance and properties for example the bump around 300hz is the resonance of the suspension, it has a good phase response staying under 45 degrees across the most important regions of the spectrum. For instance you can help determine where an amplifier might work at its operational peak and match your enclosure design to suit. Maybe one of the most important aspects to examine in this situation here is the drivers health, so how do you determine that?

Before we dive in lets check the only reference parametes i have to date.

Lets go back to the pair of graphs, Notice how the first graph has a smooth curve in the bass region whereas the second doesnt. It has peaks an exemplary one around 43hz, Scattered and non-linear this really is a strong indication that there is an issue with this driver.

Unfortunately comparing it to Marks graph which looks to have some kind of smoothing applied, its hard to tell, both responses look very similar so theres no point looking there. One thing immediately obvious checking the TS parameters was Marks M(ms), averaging our two results its 90% out, Re another whopping 66.5% difference… Not good so lets break it down and work out the deviation from marks results.

DATS v3 Deviation chart

Module 139.7417.61g11.63ohm0.35950.42422.3540.7963
Module 243.2415.75g11.65ohm0.35850.41662.570.7518
Deviation %8.5%66.5%89%28.6%31.2%13.5%4.3%

The “TEST BOX” is a 18mm MDF enclosure built as close to 0.2 cuft as possible its lined in acoustic foam from, internaly braced and soaked in resin to be not only rigid and reduce vibration but harmonicaly dead. Swaping drivers is real easy with the removable baffle and the precut special price efoam keeps everything air tight.

See also  ANL Fused Distribution Block

I had a baffle from an older project that i could repurpose, it was used for a 130mm coaxial and since the Jordan Watts modules outer diameter is 135mm it fit perfectly.

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