DATS v3 questions

[shadowplay62]

I have an old dual core/2GB ram with win7 and works fine. I have an i5 quad core series 8/4GB ram with win 11 and it's a PITA: in the same time I install a win 11 update my brother installs from scratch Archlinux with KDE GUI and all the apps on a 12-yo i5.

 

[adason]

Is dats reliable for measuring coils? Inductance? Better than dmm?

 

[NeonDriver]

I believe the DATS to be excellent at measuring coils (and capacitors). Not only do you get an actual value at 1k or 10k, but you can see the value at any given audio frequency.

 

[adason]

I have not measured with DATS for a while, so when a friend returned some subwoofers, i could not resist, i took one woofer out and measured it. I had to, because there is inductor already inside the box which could not be bypassed.

Here are some data. Its 15" PA goldwood, unknown model, 8 ohm, 37 Hz Fs, supposedly 850 watts continuous. Never tested that 🙂

 

[rayma]

Typo corrected.

 

[Dave Bullet]

If the pole piece is vented, then make sure there is clearance. Ideally you'd measure them free air mounted vertically as per:

 

[adason]

Ok, here is some nice dats puzzle for you.

Imagine jamo 15" woofer. Don't remember any details. Here it is in my home theater system, in closed box. Fs is around 54Hz. Normal stuff.

 

[adason]

Now imagine you put the same 15" woofer on open baffle, kind of U shape. Kind of isobaric, two after each other. Back to back, to reduce distortion. Offcourse one with flipped polarity, to work in unisono. Now the impedance is doubled, as they are in series. Amps love that for lower distortion. But Fs dropped to half too! Which is a good think. Open baffle with little eq goes 20Hz flat, and sounds way better than closed box. Offcourse has to be away from the walls.
Chew on this.

 

[Dave Bullet]

I'd like to apply a voltage divider to try different drive levels for TSP measurements. As an example, my Qts always measures higher for SBA drivers and I believe SBA use a higher drive level than DATS can supply.