Are my phase-curves OK?

[lasse]

Hi,

In the linked thread:
http://techtalk.parts-express.com/fo...eally-that-bad

We have learned a lot about phase and related matters in the design of speakers.

All the things appear to me as being quite useless if one makes a mistake when extracting phase from the measured SPL data for the speakers.

As a “sanity check”, can you look at the attached picture and say if you think that the phase-curves seem OK?

Best regards//lasse

[billfitzmaurice]

The only time phase matters is when the combined shift in the vicinity of the crossover approaches 180 degrees. So long as that's not the case you're good.

[dlr]

Why does your midrange SPL stop at 10K?

dlr

[lasse]

Why does your midrange SPL stop at 10K?

dlr

Actually, I don´t know.

Will check.

Later//lasse

[lasse]

Hi all,

This is a new version of RFL-3way, this time including the woofer. (and a picture of the system under test/development)

The responses rely on the assumption that the tweeter is one inch in front of the mid and the woofer (that can be adjusted easily as can be seen by moving the mid/tw unit)

Best regards//lasse

[Dave Bullet]

Are you using extracted min phase for all drivers? Also - did you remember to enter a -ve Z offset on any drivers relative to the tweeter voice coil? I see from the picture your T/M box is sitting back from the woofer. so probably ok on mid / woofer voice coil offset. But check all drivers anyway from the intended listening distance in your simulation. I simulate at 2 metres for a 3 way.

[Dave Bullet]

To get the woofer tracking better with the midrange (I'd prioritise this over mid/tweeter tracking), you want to try and smooth that hump between 500 - 1000 Hz. Try adding a resistor in series with your 44uF capacitor (this will reduce the slope) but increase the capacitor value to increase the "cut". Shunt resistors are helpful at shaping slopes and they also help increase impedance (although yours looks fine).

[lasse]

Are you using extracted min phase for all drivers? Also - did you remember to enter a -ve Z offset on any drivers relative to the tweeter voice coil? I see from the picture your T/M box is sitting back from the woofer. so probably ok on mid / woofer voice coil offset. But check all drivers anyway from the intended listening distance in your simulation. I simulate at 2 metres for a 3 way.

Hi,

Tes, I have extracted min phase for all three drivers with info from a common microphone position/point 130 cm at tweeter height.
I have no means of entering a listening position so I guess that the mic position is the "listener position"

The offset is the measured/guessed delta AC for the drivers and I have chosen 1 inch for the tweeter to be in front of mid and woofer.

Regards//lasse