The main purpose was to build an active 2 ways "satellites" to cover frequencies from 100 Hz and up as I have two sub woofers located in corners. I use FusionAmp 503 to power the system.
The cabinet dimensions are 260 x 440 x 224 mm and is made of 18 mm birch plywood. The front plate consist of 2 layers of plywood chamfered on 30 mm at 45°.
One layer of 2 mm bitumen plus one layer of 15 mm felt and melamine foam are placed inside.
Drivers are the new Purifi PT6.5W04 NFA01 (to gain 1.7 dB efficiency) and the Bliesma T34B tweeter mounted on "Pida (Petr Kocourek)" OSWG waveguide
To much of my surprise, I received the new Purifi drivers with serial numbers 00001 and 0002 !
Measurements of each drivers have been taken from +/- 180° both horizontally and vertically in 5° step. I did use VitiuxCAD to simulate the corrections needed.
Final design (for the time being...) was acoustic LR4 at 100 Hz and 1.25 kHz
emphasis on Power response (decreasing slope of 1 dB/octave and in room response along with listening windows
Here are untouched real measurements taken and imported in VituixCAD for presentation. The 2.5 dB bump at about 1.2 kHz is introduced to correct the LR4. I think that power response, DI, in room response and listening windows are well behaved.
We can see the effect of LR4 crossover effect on the vertical polar response by the way (but still a 30° freedom around the crossover region though.
Distortion is not bad either both at 90 dB_1m or even at 100 dB_1m
And now what about the sound ?
It's always difficult to stay objective after having spent weeks on this project but I find the sound at the same time soft and precise with great dynamic when necessary. I'm particularly impressed by the Bliesma T34B in Pida waveguide which can bring very high level with limited distortion as low as 1 kHz.
It's time now to enjoy listening to music on my new system for a while...
The cabinet dimensions are 260 x 440 x 224 mm and is made of 18 mm birch plywood. The front plate consist of 2 layers of plywood chamfered on 30 mm at 45°.
One layer of 2 mm bitumen plus one layer of 15 mm felt and melamine foam are placed inside.
Drivers are the new Purifi PT6.5W04 NFA01 (to gain 1.7 dB efficiency) and the Bliesma T34B tweeter mounted on "Pida (Petr Kocourek)" OSWG waveguide
To much of my surprise, I received the new Purifi drivers with serial numbers 00001 and 0002 !
Measurements of each drivers have been taken from +/- 180° both horizontally and vertically in 5° step. I did use VitiuxCAD to simulate the corrections needed.
Final design (for the time being...) was acoustic LR4 at 100 Hz and 1.25 kHz
emphasis on Power response (decreasing slope of 1 dB/octave and in room response along with listening windows
Here are untouched real measurements taken and imported in VituixCAD for presentation. The 2.5 dB bump at about 1.2 kHz is introduced to correct the LR4. I think that power response, DI, in room response and listening windows are well behaved.
We can see the effect of LR4 crossover effect on the vertical polar response by the way (but still a 30° freedom around the crossover region though.
Distortion is not bad either both at 90 dB_1m or even at 100 dB_1m
And now what about the sound ?
It's always difficult to stay objective after having spent weeks on this project but I find the sound at the same time soft and precise with great dynamic when necessary. I'm particularly impressed by the Bliesma T34B in Pida waveguide which can bring very high level with limited distortion as low as 1 kHz.
It's time now to enjoy listening to music on my new system for a while...
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Thanks,
I can't do that now but will keep it in mind for my next measurement cession but I think that it will be too much for the PT6.5W.
I have a pair of full range smaller monitor using the PT6.5X though, when I will have enough spare time I will make a swap (with filter adjustment) and will test it at 105 dB first and according to the result at 110 dB/ 1m.
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Yes, It was really nice to see that the original grill can be fitted without much problems to protect that expensive Be dome !
Below comparison with/without grill on axis and at 30°. I did the test on a 180° range and the "worst" case was on axis
Below comparison with/without grill on axis and at 30°. I did the test on a 180° range and the "worst" case was on axis
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Thanks everyone for the kind words
As I have both the X and W version of the Purifi PT6.5 driver, I will, when possible (means enough consecutive spare time), make a swap in the same enclosure (P30) of the drivers and will measure RAW response of both including distorsion at the same acoustic reference level
I will publish them in this thread.
As I have both the X and W version of the Purifi PT6.5 driver, I will, when possible (means enough consecutive spare time), make a swap in the same enclosure (P30) of the drivers and will measure RAW response of both including distorsion at the same acoustic reference level
I will publish them in this thread.
So how exactly did you mount the grill in the waveguide? It's the only thing holding me back from sticking the t34b in waveguide. Also how is the grill removed from the stock tweeter? Thanks
I use cyanoacrylate glue to fix the grill on the waveguide. If I had to do now, I would use rapid epoxy.
I followed what Stan recommended to me : 10 min in a 70°C oven (check the real temp first !) After that it is quite easy to remove the grill. Rember that grill is a metal attracted by strong magnet nearby. Frankly it's not difficult
I followed what Stan recommended to me : 10 min in a 70°C oven (check the real temp first !) After that it is quite easy to remove the grill. Rember that grill is a metal attracted by strong magnet nearby. Frankly it's not difficult
Great to show these details - thanks!
Did you try to cover the grove for the grill and do a measurement? Sometimes these little groves have influences similar to what's shown here.
I have to design a speaker for very high frequencies for a customer for measurements and these little surface disturbances all leave their mark, but often at very high frequencies.