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Old 9th April 2008, 04:24 AM   #21
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Default for Lipinski studio monitors

and Parts List.

note: try to get resistors for R2 on the attenuation circuit of 20/25W for each 100W of Amplifier power with speaker power (XT25TG) ~55W.
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Old 9th April 2008, 04:53 AM   #22
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Thanks for all this Inductor! Where did you get these plans from? Looks like something I would like to implement especially since I will be biwiring. I got the Vifa midrange drivers from a friend who had 4 extras. Also I suspect that the XT25 will need impedance compensation as sreten suggested.
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Old 9th April 2008, 05:19 AM   #23
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Quote:
Originally posted by audio_moksha
Thanks for all this Inductor! Where did you get these plans from? Looks like something I would like to implement especially since I will be biwiring. I got the Vifa midrange drivers from a friend who had 4 extras. Also I suspect that the XT25 will need impedance compensation as sreten suggested.
"As is". You are free to experiment... I don't think it will need one. Why do you suspect? You can always change it if you don't like. It's also padded by the L-pad.

Accoustic xover ~2K0.
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Old 9th April 2008, 11:09 AM   #24
sreten is offline sreten  United Kingdom
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Quote:
Originally posted by audio_moksha
Thanks for all this Inductor! Where did you get these plans from? Looks like something I would like to implement especially since I will be biwiring. I got the Vifa midrange drivers from a friend who had 4 extras. Also I suspect that the XT25 will need impedance compensation as sreten suggested.
Hi,

Impedance compensation would more of an issue if the c/o had
significant attenuation (therefore high source impedance), as it
is attenuation is minimal and the impedance peak is "buffered"
somwhat by the 15R resistor.

see ZD5, for accurate low Q slopes the tweeter needs a LCR.

Inductor's c/o values seem to be in the right ballpark but
it would be interesting to know how they are derived.

The bass mid driver wiggle at 1kHz would be an issue for me,
as would the amount of baffle step compensation, the tweeter
level indicates to me not enough BSC.

/sreten.
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Old 9th April 2008, 12:16 PM   #25
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Quote:
Originally posted by sreten

... as would the amount of baffle step compensation, the tweeter
level indicates to me not enough BSC.

Check again with two speakers (2xMG18). You can adjust on the compensantion/attenuation circuit of the tweeter if you don't like the desired computed attenuation (~3dB).

audio_moksha, take special care on the inductor L1, at full operational use you should get a double power inductor for the pair of two speakers, or double the diametre of cable in it (inductor). Also choose a low loss or internal resistence inductor like the Tritecs Ferrobars or similar.
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Old 9th April 2008, 01:15 PM   #26
sreten is offline sreten  United Kingdom
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Hi,

Nominal tweeter attenuation appears to be 1.2dB.

/sreten.
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Old 9th April 2008, 03:46 PM   #27
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I guess the best thing to do would be to take actual measurements. So are both hi and lo pass filters 2nd order LR?
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Old 9th April 2008, 05:39 PM   #28
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Quote:
Originally posted by sreten
Hi,

Nominal tweeter attenuation appears to be 1.2dB.

/sreten.
I measured at around overlap frequency (~3dB@2K0). It might differ over bandpass. It's important for balanced overall.


Quote:
Originally posted by audio_moksha
I guess the best thing to do would be to take actual measurements. So are both hi and lo pass filters 2nd order LR?
Woofer is a 1st order (inductor L1) with a R-C Zobel.
Zobel here
http://www.trueaudio.com/st_zobel.htm

Tweeter is second order.

The transfer output from this xover (electrical) is very similar to what the picture of fig.3 shows on the stereophile document. The summation of both (electrical/output of the drivers per si and room conditions) will give your final result.

Interesting to note how the peak from the woofer after 1K/2K is brougth down by the xover (in a very similar way to this picture) and blends with the tweeter.
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Old 9th April 2008, 07:07 PM   #29
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Inductor and sreten, I cannot thank you enough for going out of your way and helping out a beginner I can only hope that in time I get to be as knowledgabe as you guys and in turn help someone else out. I have a lot of homework this week (almost done with college~!) but this weekend I will hopefully take some measurements using SW as well as build the cabinets.
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Old 9th April 2008, 11:14 PM   #30
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Default Congratulations!

You are welcome. You are very fast with your work. Faster than you maybe only Mr. Lipinski. And a nice designer for sure. I admire his padding around the tweeters (you don't have so many problems with differences in phase when you go high in frequency) like so many others. Expect to see some pictures. This his only a prototipe. Maybe one day we can compare our (your) work to the real network.
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