Set up the system for the second Concerts in the Park show of the year....last month is when the OT12 decided to haunt me, but that's all fixed. Now for round two on the second show. The top subs in my stack are the 20 inchers. Stuck my head in to make sure everything was cooking, but it sounded like it was dead. I shut down the other subs and it was barely making noise.
Wasn't much we could do at that point - the other 4 would have to carry the load....
During the show, I started hearing some rattling from one of the wide subs. Couldn't figure it out on the fly. It wasn't horrible, just a rattle occassionally. So, now I had two issues to deal with.
Drug the amp rack and those two subs out of the trailer and started to test with a 60 hz tone. First was the skinny sub. Output was really low. Plugged into the other sub (now dubbed the rattler...after all we're coming into summer in Texas - seemed appropriate). The output was the same. Plugged into one of the other amps and it blew my head off. hmmmmmm.....
Got out the volt meter and started comparing. At this point I guess it would be good to know that I run 3 Crown XLS1500 amps bridged to drive the 6 subs - 2 on each amp. Checked the voltage output on the first amp - 47.5 volts. Second amp - 52 volts. Third amp that the skinny sub was on - 6 volts.......YIKES.
So now started the trouble shooting. Was the amp bad? Was there a cabling issue? The amps are all daisy chained from the driverack. I swapped output wiring in the daisy chain with no change, then went straight from the driverack with the same result.
Looks like the XLS1500 has taken a dive. I have other amps available, so I started testing to see if I could get one to put out something close in voltage. The XLS1000 could only hit 30 volts bridged (baseline being 47-50 on the other two).
On to the xTI2000. In stereo mode, it was only getting to 33 volts. In bridged mode - it was way too much, hitting almost 70, even limited in the dsp by 3db. So, I limited the amp by 6 db and got it down to about 59 volts.....still too much. One more notch should get it in a usable range. Yeah right......the limit options inside the amp are -3, -6, -12. Crap! I think the -9 probably would have gotten me where I needed to be. The -12 pulled all the way down to 33 volts.
So, I ordered a new XLS1502 a little while ago. Fortunately, I can get through tomorrow night's show without that amp. It's an Opry style show that really low volume. We just use the two skinny subs and all they get is the bass guitar.
The new amp will be in over the next couple of days. Downside is that the new style 1502s are a black front, while the old ones are silver. Why an old, fat, soundman in shorts and t-shirts would worry about asthetics is beyond me...but, it happens.
By now, those of you who haven't fallen asleep or moved on to debate politics on social media, are probably wondering about the other sub....you remember, the one with the rattle?
Well, after 15 years - I finally blew a driver. This was one of the first 2 T39s I built. I tested it and it sounded ok until you gave it a little juice, then it started rattleing. I could tell it was coming from the driver chamber, so I opened it up.
I knew right away something was amiss when I could see the spider separated from the magnet structure.
Just have to get everything buttoned up and ready to go by 5/15 - next time we drag everything out for the next Concert in the Park.
