John Reekie
Technologicality, at work and play

Update to Neo3 PDR tweeter mount

In the article Refining a 4-way open-baffle speaker with the miniDSP 2×4, I noted a dip in the on-axis frequency response of the “naked” Neo3 tweeter. The on-axis curve is here in red:

Figure 15. Tweeter frequency response at 0, 30, 60 and 90 degrees

A dip like that is hard to remove – you can’t EQ it, as then the off-axis response will have a peak in it. Using Edge, I came up with a baffle for the Neo3; this is a quick prototype:

Prototype Neo3PDR Baffle

Prototype Neo3PDR Baffle

The on-axis response is shown in purple in the curve below. It’s not flat but it’s easy to EQ – the EQed response shown in green. I haven’t measured the off-axis response yet – that will tell if having a baffle this shape is any improvement. At the least, the baffle lifts up the bottom end, making the tweeter strain less with a low crossover point.

New Neo3 PDR tweeter baffle measurements, on-axis, with and without EQ

New Neo3 PDR tweeter baffle measurements, on-axis, with and without EQ

Update April 16th 2012

Here is the off-axis measurement (with no EQ). In the frequency range from 3-10 kHz, the frontal lobe is wider than with the ideal dipole, but as you can see it still behaves like a dipole with a distinct null at 90 degrees. (And this is not intended to be a 100% precise measurement, the mic position was determined with a tape measure and eyeballing the angle of the baffle.)

Neo3 PDR new baffle 0 30 60 90 degrees

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