My take on FAST With TB- 1139SI and PS95-8

[hatemii]

I sure hope my 100w/element is enough I will take some measurements tomorrow and adjust acordingly.

 

[Cal Weldon]

I hope so too. When I tried implementing a FAST, I had to pad down the other driver so much it sucked the life right out of it, so to fix that I simply added a plate amp and haven't looked back. It's a fine little driver.

 

[Godzilla]

I'm a plate amp kind of guy. When I saw the drivers being used I was surprised to read there wasn't one.

 

[xrk971]

I think that's wishful thinking there X. That TB driver is a great little unit but it eats watts for breakfast. I have only been able to use it with it's own amp. A standard 2 way is a tough go. Hatemii might need to consider a plate amp and bi-amp the system.

Are you saying the 84dB at 1watt spec is overly generous? 2.83v for 4ohm driver is 2 watts. 2 watts doesn't get 87dB is what you are saying then?

 

[Cal Weldon]

I believe the 84 is a fish tale. It might peak at 84 at 1K but as mentioned, this baby is 'hungry-hungry-hippo'. Check the Xmax. I'm thinkin' that's one really overhung driver.

EDIT: I just looked at the FR graph at PE. Methinks they be foolin' ya.

 

[hatemii]

I did some measurements and EQ magic. This is what the response looks now. Measured with calibrated EMM6 at roughly 0.5m and centered at the Dayton.

 

[hatemii]

That EQ is for the Dayton. XO is 350 on both drivers. -5db for the Dayton.

 

[hatemii]

Still too bright. I will need to do some more tweaking. Hi-Hats in particular sound too bright and loud.

These Daytons might work rurprisigly well in a car mounted 30deg off axis...

 

[xrk971]

30 deg off axis was also my recommendation for listening to the PS95, and a lot o people picked it, so it must have sounded decent to many people.

http://www.diyaudio.com/forums/full...2in-4in-drivers-round-4-a-37.html#post4452354

PS95 at 30 deg off axis is the green line in the plot below:

 

[hatemii]

That would work if the listening spot would be set. In my case it is not and I'm actually prety much on axis on the right speaker.

The fact that the treble is clear even to our kitchen which is 180deg off axis and partially behind a wall from the speakers tells something about the situation.

 

[hatemii]

I chaged to Hersch XO @ 350Hz. And did more EQing. This is the response now at relatively the same distance. Delay is set at 1.42ms.

 

[xrk971]

Nice!!! Must sound very very convincing with percussions.


Can you show the measured XO plot (LF, HF, combined)? 1.42ms is the Harsch XO delay is for 350Hz and assuming there is no acoustic centers offset between the woofer and tweeter. But that is typically 10mm to 25mm depending on how deep the basket and whether the VC is under or overhung. You may need to delay an additional 0.04 to 0.06ms. It's easy enough to try to see if the tweak can make the step response even better.

 

[hatemii]

I will make some measurements tomorrow.

On some material it sounds ok now but with some different there is still something that is not right. It might be due to the large difference in the sensitivity of the drivers. I guess I will have to listen some more when I get time.