There is a reason I got them for free! [emoji1787]Those b&w tweeters have seen better days
Did you also get the PRs for free?
Check Dayton's PRs. They have a wide range at reasonable prices.
With a midwoofer of that kind, I would use adequate partners.
I modeled the Dayton PRs too. the SB seems to model a bit better. the Purifi ones in pair are still best. but very costly.
I don't remember if this Review on Purify's Speaker'd Demo Kit was posted or not , but along with Norman's review it's very inspiring.
Purifi PTT6.5 Woofer and 1ET400A Amplifier Technology Review - Reviews - Audiophile Style
Purifi PTT6.5 Woofer and 1ET400A Amplifier Technology Review - Reviews - Audiophile Style
I've also along with everyone else been thinking of what tweeter to go with this amazing woofer, and I had a couple of ideas floating around in my head. First idea to just throw into the ring. - I wonder if you took the LS-50 driver and crossed it over at 1000 Hz - ( or whatever is the best point) to the Purify woofer..... so you get a very well regarded driver that sounds wonderful , but has a hard time going loud because it's asked to go to low/ do too much, and then you take that one major fault away ..... thoughts?
I thought that too but it doesnt seem to bother HiFiCompass latest build
(thats a PR on each opposing side of his cabinets) 
I thought that too but it doesnt seem to bother HiFiCompass latest build
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Thanks!
After a bit of searching reveals that putting them on opposite end is actually the preferred arrangement.
Hi XRK , I know that you, and your family both really liked the Scan Speak 10f 8424 in your FAST design are you going to try this woofer in that box or design to see what you think?
- maybe that driver and a Super Tweeter - maybe a ribbon ?
I know after all the positive feedback on that design it was one of the first things I thought of trying .....
- maybe that driver and a Super Tweeter - maybe a ribbon ?
I know after all the positive feedback on that design it was one of the first things I thought of trying .....
If you look at the measured acoustical phase, it has the hallmarks of almost flat with the characteristic 55deg rise near the XO. This is as good as a Harsch XO gets. You won't see any LR2 or LR4 XO with inverted tweeter look anything like this.
This type of acoustic phase response gives this step response:
@mainframe - more on the Harsch XO here: S. Harsch XO
It aims for quasi-transient perfect (correct absolute polarity of woofer and tweeter, time and phase aligned, capable of a right triangle shaped step response). It is normally only used in DSP as the delays require either a woofer with very high bandwidth to reach a high XO point in order to keep the physical delays small. In DSP, this is not an issue as several milliseconds of delay are possible.
Basicss of Harsch XO:
1. Set the low pass filter for the woofer as a 4th order Butterworth at central frequency, fc for the XO centerpoint.
2. Set the high pass filter for the tweeter as a 2nd order Bessel at fc.
3. Set the delay of the tweeter equal to 1/2 of the period of one cycle at fc.
4. Use all positive phase on woofer and tweeter.
Here is ideal Harsch XO at 1khz:
@hallcon: I was also going to try the PTT6.5 in a FAST with with a 10F/8424 - but it has such an amazing mid range, that seems like a waste. I will try it nonetheless.
If it means anything, I am listening to both the 10F/RS225 with 1st order transient perfect XO and the PTT6.5/RS28F with Harsch XO. The voicing is eerily similar despite one having a XO at 900Hz and the other at 3.6kHz. This means that the PTT6.5 has very low distortion in the midrange where the 10F really shines.
Listening to this speaker a lot more today and I really like it. I think putting it in a tapered PMC like TL and keeping the WG dome tweeter will make this into a very impressive speaker. I am going to start designing a new TL in Akabak from scratch. First get the approximate folding on a sketch.
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