Help with 1Bs

bigaltx24

I recently moved to a new house and haven't had a lot of time to set up my SDAs correctly. Last Sunday I finally had some time to sit down and listen to them. It only took about 5 minutes to figure out something was wrong. Did a right-left with the balance and found the dimensional drivers aren't working in the right speaker. I pulled the drivers, checked their connections, found nothing. I then swapped the dimensional drivers for the regular drivers, still no sound from the dimensional drivers. I pulled the PR and found that two of the tabs that hold down the low frequency board had snapped and one of the wires to the large inductor had broken. I soldered the wire back, buttoned them back up, still no dimensional drivers. Checked continuity on cable, it was good, pulled PRs on both speakers, checked all wires to both crossovers, I can't see anything out of place. Any suggestions, right now I'm pretty much stumped.

Outfitter03

Did you check continuity on the severed inductor following soldering? How did you strip the coating off inductor prior to soldering?

bigaltx24

I checked continuity after soldering, it was good. I didn't need to strip the wire, I broke right at the solder joint. I just cleaned off old solder, got the broken piece out, and re soldered.

Schurkey

The joint you repaired is still somewhat suspicious. I'd double-check that. How about the other lead from that inductor--is that solder joint wounded?

Any chance that the 185uF capacitor (130+55 electrolytic caps as supplied by Polk) has lost continuity? Another defective solder joint on one end or the other of those caps?

Wear or damage to the conductors in the SDA jacks? Maybe one blade of the cable isn't making contact?

Since its the SDA drivers that aren't functioning, keep in mind that the fault could be in the opposite-channel cabinet!

bigaltx24

I though about it being in the other cabinet, I need to print the schematic and get busy with my VOM.

bigaltx24

So I finally got a chance to to get busy with the VOM. Went all the way through both crossovers, everything checked out, now I'm really stumped. I had printed the SDA troubleshooting guide so I started reading it, thinking it might give me a clue as to what's going on. In the first part it says if the dimensional array is not working on one side, it may be wired out of phase. I checked the back of the amp, sure enough, I had one channel wired out of phase. Lesson learned, when troubleshooting, never take anything for granted. Start at the source and work your way out.

Schurkey

Glad you got it fixed. Thanks for the update.