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View Full Version : [Help Needed] 3 Way Crossover



jacob.simpson
02-01-2010, 10:47 PM
I am looking at Schematic for 3 way crossover of any new Polk RT line Models,
like RTiA9 or A7 or the previous gen to these, this is for DIY for my brother using db804 and monitor 30 as mid and highs, please help with this.
And how to attenuate the 86db sensitivity vs M30 89db sensitivity (impedance is not an issue will be wired in series to get 8ohm load for db's)

jacob.simpson
02-02-2010, 12:33 AM
mmm dont want this getting lost :p

ShinAce
02-02-2010, 12:12 PM
Attenuation is done with an L-pad. Be careful, as sometime sensitivity is stated as X dB/W/m and sometimes as Y dB/2.83V/m .

The 2.83 volt is reliable, but then you need to make sure all drivers have the same impedance to avoid causing thr amp trouble.

jacob.simpson
02-02-2010, 12:17 PM
Attenuation is done with an L-pad. Be careful, as sometime sensitivity is stated as X dB/W/m and sometimes as Y dB/2.83V/m .

The 2.83 volt is reliable, but then you need to make sure all drivers have the same impedance to avoid causing thr amp trouble.

Thats great thanks for the important clue on this,
now to the main ? still unanswered...:)

zingo
02-02-2010, 12:22 PM
If you email Polk, they may send you the schematics for either of those speakers. It will be up to you at that point to incorporate them into a working XO with trial and error, or computer modeling programs.

ShinAce
02-02-2010, 12:40 PM
Or you can try post #11 in this thread:
http://www.polkaudio.com/forums/showthread.php?t=38755

ShinAce
02-02-2010, 12:41 PM
No wait, you said RTi, forget about my link.

jacob.simpson
02-02-2010, 07:03 PM
If you email Polk, they may send you the schematics for either of those speakers. It will be up to you at that point to incorporate them into a working XO with trial and error, or computer modeling programs.

Think the best is to email Polk.
thanks a lot for replies though.