DATS vs Acoustic Elegance

[DeZZar]

Cant really find any specific published materials on how DATS specifically calculates each param but its all based on the impedance curve I think - progressively solving for most params based on their mathematical relationships with each other.

BL seems to have a few different ways to calculate it, and from a manufacturers perspective they are probably basing the physical dimensions approach (length of wire etc). Dats doesn't know this so there's no real surprise its potentially going to come up with a different number based on an electrical estimate.

[Chris Roemer]

MY DATS doesn't calc. "BL" TIKO.
From DATS, I plug these into WinISD: Qes, Qms, Fs, Vas, Re, and Le; also (from other sources): Sd, Xmax, and Pe.
WinISD then calcs: Qts, Mms, Cms, Rms, BL, Vd, and USPL and SPL.

[DeZZar]

MY DATS doesn't calc. "BL" TIKO.

Should do. Once you measure the driver including VAS open the Driver Editor. BL is listed in N/Amp (which is 1:1 with T/m). This is a V3 unit.


If you plug these numbers into WinISD as you suggest the BL calculated is bloody close...

[camplo]

Thanks Chris! I've figured out that my 18H+ woofers are within spec but unfortunately the 16ohm 15ms I have, have qes specs that are double what it should be and this not good.

incorrect Vas is throwing off my DATS prediction.....call it due to break in.....never the less....reverse operations allowed me to get BL numbers for speculation and WInISD prediction made it even simpler to get predictions with different values quickly...

The 18H+ are looking to be fine but my 16ohm 15m have dbl the Qes I am looking for....highly doubt they will drop 50% due to break in....

[JRT]

Looks like your 15M is a good candidate for the MAPD alignment, which can provide improved linearity.


See the MAPD alignment white paper (at the Internet Archive at the link below) authored by George Short, of what was North Creek Music Systems (now out of business).

https://web.archive.org/web/20100413....com/MAPD1.htm

The MAPD is an acoustic suspension loading with improved linearity provided by the aperdiodic damping of an airflow resistance, and is essentially an advanced sealed alignment, so it exhibits the second order high pass of a sealed alignment with improved linearity. In his MAPD white paper, George Short recommends an acoustic high pass Q of approximately one. Not mentioned in the whitepaper is that Q would lend itself well to use in a third order sealed alignment (eg. exhibiting BW3 acoustic highpass) achieved by cascading a first order high pass with the MAPD's second order highpass.

The succinct white paper at the link above is based on George Short's masters thesis, available at the link below. At 120 pages, the thesis goes into considerably more detail. Start with the white paper.

https://vtechworks.lib.vt.edu/handle/10919/45955

[camplo]

Thats some interesting reading JRT.....though that design is tempting me to keep my under power (low Bl) drivers.....I did take note to the theory...The way my bass boxes are designed, I have serendipitously created a dual opposing MAPD alignment lol....Its a U shape box where the bottom of the U has a much lower csa than the sides of the U.