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I had some 4.5mH E-core inductors laying around. These i used to filter the lower woofer (appr. 400 Hz). The upper woofer only has one 0,82mH Alpha core inductor (also laying around ;-) ) and is crossed @ appr 1900 Hz with the RSQ8P which has a 2nd order electrical filter comprising 6,8µF and 0,68mH. Padding is done with a 1,8ohm resistor.
I fired it up and was pleasantly supprised. The image is much bigger, the transistorsound has gone (eventhough the freqcurve did not alter that much form the 'like a transistorsradio sounding'-2way WTW).
I will post some measurements asap.
Thanks a lot for your input!!!!
And the RSQ8P sounds less stressful crossed @ 1900 Hz in stead of < 1500Hz.
Regards,
Ramon
PS the filtered curves comply with 3rd order Butterworth for both high and lowpass.
I had some 4.5mH E-core inductors laying around. These i used to filter the lower woofer (appr. 400 Hz). The upper woofer only has one 0,82mH Alpha core inductor (also laying around ;-) ) and is crossed @ appr 1900 Hz with the RSQ8P which has a 2nd order electrical filter comprising 6,8µF and 0,68mH. Padding is done with a 1,8ohm resistor.
I fired it up and was pleasantly supprised. The image is much bigger, the transistorsound has gone (eventhough the freqcurve did not alter that much form the 'like a transistorsradio sounding'-2way WTW).
I will post some measurements asap.
Thanks a lot for your input!!!!
And the RSQ8P sounds less stressful crossed @ 1900 Hz in stead of < 1500Hz.
Regards,
Ramon
PS the filtered curves comply with 3rd order Butterworth for both high and lowpass.
Congratulations!
I am happy that you are proving the principles. I don't know how close you are to have done it exactly, but you are on your way. Measure carefully and tweak in the long run.
P.S. The on axis FR can be almost the same as before, the energy in the room is different now. I have explained why and how in my previous posts.
I am happy that you are proving the principles. I don't know how close you are to have done it exactly, but you are on your way. Measure carefully and tweak in the long run.
P.S. The on axis FR can be almost the same as before, the energy in the room is different now. I have explained why and how in my previous posts.
I had a pair of RSQ8P for many years. They worked fine with 1400 Hz 4th order passive x-over. When I moved on to using very steep digital x-overs, 1400 Hz did not work well. 1800-2000 Hz sounded better here. I think the reason for this is that the steep x-over loads the driver with up to 6 dB more input at the x-over frequency, og also much more right above the x-over.
As someone already pointed out, the distortion increases somewhat at low frequencies, although it stays very low, shown in the graph below. Also note that the freq response is more or less flat to 1 kHz.
As someone already pointed out, the distortion increases somewhat at low frequencies, although it stays very low, shown in the graph below. Also note that the freq response is more or less flat to 1 kHz.
An externally hosted image should be here but it was not working when we last tested it.
I think we have exchanged some e-mail as well?RSQ8P said:
Well. I dont have the system with RSQ8P and Excel W21 anymore. A lot of reasons for that, the main being that I wanted to build something new. I sold the entire system to a friend living nearby, so I can listen to it for reference.
The main problem with this configuration is that the W21 is not at its best above 1 kHz, and the RSQ dont like to be crossed over too low. When I moved into digital X-over, I exprerimented a lot with the x-over frequency, and found that the RSQ would sound a bit harsh if crossed over below 2 kHz. You can find support for that subjective observation in the THD measurements. So - the problem was the 1-2 kHz octave, where neither the RSQ or the W21 was an optimal solution. I decided first to "fill the gap" with 5" Excel (W15CH001), crossing over at 500 and 2 kHz. In the final system I also ditched the RSQ over a Mundorf AMT, which I think is better, although it cannot be crossed over below 2,2 kHz.
To conclude: the W21 + RSQ8P system sounds somewhat forward in the 1-3 kHz range compared to my new W22+W15+Mundorf AMT system.
We made a broad 1,5 dB dip in the frequency response around 2 kHz to compensate for this, with some success (the "character" of its sound is still there, only a bit attenuated). X-over was set at 1,8 kHz, 100 dB/oct slope.
My recommendation with the RSQ is to cross over at 2 kHz, and combine it with midrange(s) that behaves well at this x-over frequency. 8" is not the best choice I think. 5" Excel W15CH001 is absolutely wonderful, and highly recommended.
Hi Erik,
Thanks for the reply. The 8" woofers i use are very well behaved @2kHz. Even more so that i only filter with a single inductor. About the harsness of the rsq below 2kHz: i agree with you there.
I surely won't ever part with these rsq's, eventhough in the future new projects will come and take its place.
It is just to fine a piece of loudspeaker history.
Thanks for the reply. The 8" woofers i use are very well behaved @2kHz. Even more so that i only filter with a single inductor. About the harsness of the rsq below 2kHz: i agree with you there.
I surely won't ever part with these rsq's, eventhough in the future new projects will come and take its place.
It is just to fine a piece of loudspeaker history.
I stand corrected: a masterpiece it is.
They nearly were lost in the DHL distributing line btw ;-(
I waited for nearly a month for them to arrive from Germany in the Netherlands. I almost gave up hope.
And the nice part is that 30 minutes drive from here, i can have them fitted with new foils - if it ever came to replacement. Stage Accompany resides in Hoorn (30 minutes drive from Haarlem).
PS What active solution did you choose hardware-wise?
I am thinking of purchasing the Groundsound active filter boards.
I have read a lot about this in K+T and Hobby Hifi: looks promessing.
They nearly were lost in the DHL distributing line btw ;-(
I waited for nearly a month for them to arrive from Germany in the Netherlands. I almost gave up hope.
And the nice part is that 30 minutes drive from here, i can have them fitted with new foils - if it ever came to replacement. Stage Accompany resides in Hoorn (30 minutes drive from Haarlem).
PS What active solution did you choose hardware-wise?
I am thinking of purchasing the Groundsound active filter boards.
I have read a lot about this in K+T and Hobby Hifi: looks promessing.
I got my pair right off the Philips factory in Dendermonde (Belgium?), at 150 Euro a piece. There is a saying that goes like this: "If you find something you like, buy a lifetime supply, because the WILL stop making it". True enough. Had I just thought of that THEN!
Nice to know that SA still have the SA8520 ribbons.
The active filter I use is ShinOBIWAN's PC-based software XO, on which there is a looong thread on this forum:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=63078&highlight=
With a proper set-up and a great multi-channel DAC, you cant find anything that sounds better than this. It might be a PITA to set up, but the results you can get....
Nice to know that SA still have the SA8520 ribbons.
The active filter I use is ShinOBIWAN's PC-based software XO, on which there is a looong thread on this forum:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=63078&highlight=
With a proper set-up and a great multi-channel DAC, you cant find anything that sounds better than this. It might be a PITA to set up, but the results you can get....
I know! There is a shop in Haarlem (Holland) called speaker en co which had a bunch of them for over ten years ago. They sold them for sub bargain prices. ARGGHHHH.
I have been experimenting with the series resistor for the RSQ, and i must say the cement ones sound more evenly balanced than the mox (metallized oxide) ones. The later make the rsq sound more harsh.
Tomorrow i will move them up to the living room and connect them to a proper setup: Marantz CD-7 and Electrocompaniet ECI-4. I am pretty excited about listening to them.
I have been experimenting with the series resistor for the RSQ, and i must say the cement ones sound more evenly balanced than the mox (metallized oxide) ones. The later make the rsq sound more harsh.
Tomorrow i will move them up to the living room and connect them to a proper setup: Marantz CD-7 and Electrocompaniet ECI-4. I am pretty excited about listening to them.
RSQ8P said:
I have wrote about it in some power resistor looking to buy guy's thread some time ago. They said yeah yeah alright...
The cement sounds better than the MOX. Also luxury carbons like Kiwame 5W sound mushy there. Order Mills 12W, that one is even better, and the Philips will resolve the difference.
Did you do any tweaking of component value changes, or you save that and some measurements for their final installation space? (final voicing is wiser to be done there).
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