Optimizing active crossover

[atledreier]

The baffle wall will of course be flush with the front of the cabinets, yes.

Did a few measurements and eq today, and already much better. The harshness was a peak in the 500-1100 area. Brought that in line and put the crossover to 1,2kHz and the transition is much smoother.

[jerome69]

Originally Posted by Loren42

No 15" will match the directivity of the TPL-150 or TP-150H (doesn't matter) at 1 kHz and up.

The woofer may have a great response on-axis, but physics will intervene at some point due to the size of the radiating surface.

Discontinuity of the power distribution will result above 1 kHz. What that means is the SPL on axis response will be fine, but the power distributed off-axis will peter out until the TPL-150 takes over above the crossover point.

If you look at the polar plot you will see a narrow waistline at the crossover point if it is too high because there is nothing the woofer contributes to the off-axis response.

Yes I am agree with that ... for home HiFi.
Beyma is a constructor of pro drivers... Directivity is not the first concern. Imagine the distance is long and even if the angle of radiation is narrow, it is enough to cover the surface you want.
I don't try to say i am right or not, i am agree with what you write, it is an other point view.
Directivity could be a good thing in some case when you want to concentrate the wave on one place (the dance floor for example )

[Loren42]

Originally Posted by jerome69

Yes I am agree with that ... for home HiFi.
Beyma is a constructor of pro drivers... Directivity is not the first concern. Imagine the distance is long and even if the angle of radiation is narrow, it is enough to cover the surface you want.
I don't try to say i am right or not, i am agree with what you write, it is an other point view.
Directivity could be a good thing in some case when you want to concentrate the wave on one place (the dance floor for example )

I think the Beyma TPL-150H determines what type of directivity you want. That is, since the TPL-150H has a very wide directivity you are pretty much stuck with the task of mating another driver with the same directivity characteristics (at the crossover point) for continuity's sake.

[Loren42]

Originally Posted by atledreier

The baffle wall will of course be flush with the front of the cabinets, yes.

Did a few measurements and eq today, and already much better. The harshness was a peak in the 500-1100 area. Brought that in line and put the crossover to 1,2kHz and the transition is much smoother.

Excellent!

[Audiodidakt]

I believe TPL150H is constructed by Beyma for mating with 12" around 1200 Hz dispersion-wise, ref. their own design at www.beyma.com.

[Loren42]

Originally Posted by Audiodidakt

I believe TPL150H is constructed by Beyma for mating with 12" around 1200 Hz dispersion-wise, ref. their own design at www.beyma.com.

It can be, but drivers are pretty versatile devices and there is nothing preventing you from choosing a 3-way system and crossing that Beyma at 3.5 kHz if that is your desire.

The example you cited is just that, an example of one of many possible configurations the designer has at his fingertips.

[Audiodidakt]

I totaly agree; the TPL150H is CD in the horisontal plane from around 1200 Hz and far up in frequence. It's just a matter of mating with midband speaker at a frequence where both have similar dispersion, e.g. an 8" might be XO'ed with the TPL150H around 1700-2000 Hz?

[Charles Darwin]

Originally Posted by jerome69

Yes I am agree with that ... for home HiFi.
Beyma is a constructor of pro drivers... Directivity is not the first concern.

In my experience in pro circles directivity is taken a LOT more seriously than in home hifi and for a lot longer, basically since the advent of large P.A. systems in the early '70s.
Feedback can be a bastard to fix so you need to take extra care of the all the speakers and microphones directivities.