Tweeter 3 and Schematic of the SDA-SRS 1.2TL
PolkMaster1
Posts: 847
I am performing some work - rebuilding my crossover with upgrading capacitors and resistors on the tweeter section of the 1.2TL. I am using Gimpods boards which are great and a life saver compared to the original boards that Polk used!!!
I noticed two things:
1. That the schematic diagram posted in the forum for capacitors and resistors (with the exception of the 2.7 ohm resistor) are facing the negative terminal of the tweeter. However, when looking at the board, this is the complete opposite for the resistors (I have not verified the caps, but this could also be suggested - read on). I also notice that in the original crossover board in the C6 section, that the solder holes are untouched. This would indicate to me that C6 was never used in the original board - I am using C6 on Gimpods boards for a 12 uF capacitor. Is this wrong, or should that cap be located elsewhere? Could the schematics tweeter wiring diagram (from the wire output to the tweeters) be labeled incorrect? I feel totally confused.
2. Tweeter 3 (from the top) does not produce sound from both speakers. I verified that the tweeters do work. I also verified using an ohm meter that there is conductivity from the circuit to the tweeter, so I do not beleive there is an open lead in the circuit. I am not using any polyswitches or mica caps. I am wondering perhaps I forgot to jumper a section somewhere to have sound produce from tweeter 3.
I beleive Gimpods boards are a solid product and are are NOT the reason I am experiencing this. Someone also suggested that there is not much sound (or a sound beyond my hearing) being produced from tweeter 3 which is possible. Experience suggests this. However, judging that I can hear the other tweeters, and that even if I could not hear sound at those frequencies, I do feel tactile sensation (vibration) coming from the other tweeters, so l should be able to feel the sound coming from it if not being able to hear from it.
I cannot go back to the original board to verify because:
1 - i do not feel like it
2 - i removed the original caps and resistors components for new components, and then purchased Gimpods boards which required the transfer of all the components to the new board. Now the original board is blank with the original components sitting in a bag labeled 1.2TL.
Has anyone else encountered this issue?
Thanks much!
I noticed two things:
1. That the schematic diagram posted in the forum for capacitors and resistors (with the exception of the 2.7 ohm resistor) are facing the negative terminal of the tweeter. However, when looking at the board, this is the complete opposite for the resistors (I have not verified the caps, but this could also be suggested - read on). I also notice that in the original crossover board in the C6 section, that the solder holes are untouched. This would indicate to me that C6 was never used in the original board - I am using C6 on Gimpods boards for a 12 uF capacitor. Is this wrong, or should that cap be located elsewhere? Could the schematics tweeter wiring diagram (from the wire output to the tweeters) be labeled incorrect? I feel totally confused.
2. Tweeter 3 (from the top) does not produce sound from both speakers. I verified that the tweeters do work. I also verified using an ohm meter that there is conductivity from the circuit to the tweeter, so I do not beleive there is an open lead in the circuit. I am not using any polyswitches or mica caps. I am wondering perhaps I forgot to jumper a section somewhere to have sound produce from tweeter 3.
I beleive Gimpods boards are a solid product and are are NOT the reason I am experiencing this. Someone also suggested that there is not much sound (or a sound beyond my hearing) being produced from tweeter 3 which is possible. Experience suggests this. However, judging that I can hear the other tweeters, and that even if I could not hear sound at those frequencies, I do feel tactile sensation (vibration) coming from the other tweeters, so l should be able to feel the sound coming from it if not being able to hear from it.
I cannot go back to the original board to verify because:
1 - i do not feel like it
2 - i removed the original caps and resistors components for new components, and then purchased Gimpods boards which required the transfer of all the components to the new board. Now the original board is blank with the original components sitting in a bag labeled 1.2TL.
Has anyone else encountered this issue?
Thanks much!
Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart.
The other 2% will work for WalMart.
Post edited by PolkMaster1 on
Comments
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So you're doing your own 1.2's. Please photograph and take notes as I have a pair I am considering doing and my electronic abilities are very slight. Thanks, MichaelMain Family Room: Sony 46 LCD, Sony Blue Ray, Sony DVD/VCR combo,Onkyo TXNR 708, Parasound 5250,
Polk SDS-SRS with mods, CSI 5 center + Klipsch SC2, Polk RT2000P rears, Klipsch KG 1.5's sides, Polk Micro Pro 1000, Polk Micro Pro 2000, Polk SW505, Belkin PF60, Signal Cable Classics,Monster IC's, 2 15 amp circuits & 1 20 amp circuit.
Living Room: Belkin PF60, Parasound HCA2200, MIT ProlineEXP balanced IC's,Emotiva XDA-1 DAC/Pre,Emotiva ERC2 transport,MIT AVT2, Polk LSI 9's. -
Just look at post number 20 provided by xoaphexox
http://www.polkaudio.com/forums/showthread.php?69245-SDA-SRS-1.2TL-Sonicap-Upgrade&highlight=crossover
It shows 4 resistors conducting to the positive terminal and the 2.7 ohm resistor going to negative. And notice the unsoldered holes just below the first and last positive lead of the tweeter wiring. If you flip the crossover around, those unsoldered holes are designated for C6.
The picture displayed in that post matches my original crossover board showing that those holes were untouched and that the resistors lead to the same location as I stated above.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
1. The tweeters are out of phasse, so what you observed is correct.I also notice that in the original crossover board in the C6 section, that the solder holes are untouched. This would indicate to me that C6 was never used in the original board - I am using C6 on Gimpods boards for a 12 uF capacitor. Is this wrong, or should that cap be located elsewhere? Could the schematics tweeter wiring diagram (from the wire output to the tweeters) be labeled incorrect? I feel totally confused.
Tony designed the boards to be used with a multitude of SDA's, so if his online diagram says you should use C6, then do so.
2. Tweeter 3 is the main tweeter. If it is not producing sound you have something connected improperly. Since you state you are not using polys you have to use a jumper in that position.
Have you vacated both stock boards?
What city are you close to? Maybe we have someone close that can help.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
F1 -
I did not know Gimpod made schematics for his boards, let alone it be correct. I managed to find the schematics and here is where I went wrong -
C6 had a 12uF cap.
R2 was not jumpered
L-A was jumpered
Here is how I corrected it -
I removed the 12uF cap from C6
I replaced the jumper from L-A for the 12uF cap
I jumpered R2
What a difference it makes! The tweeters now have a not-so-much a you-are-there feeling, but more like a the-concert-is-here effect.
And this is just one of the speakers.
Time to work on the other set of speakers!
Thanks F1 and Gimpod!Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
By the way - the original crossovers have been vacated, so there was no going back to make any reference.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart. -
Ok, I take it you found this. http://www.gimpod.com/partsp12tl.htmlPolitical Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Ok, I take it you found this. http://www.gimpod.com/partsp12tl.html
I was able to find that webpage by using the search on this forum.
I like how Gimpod uses Sonicaps and Mills Resistor Images in his webpage.Statistics show that 98% of us will die at some point in our lifetime.
The other 2% will work for WalMart.
