| Yorkville U15B problem / heads up [message #348777] |
Fri, 08 August 2008 12:13  |
 Karl Bruhn
Messages: 12
Registered: November 2004
Location: Indianapolis |
Here Often |
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Let me start by saying I love the sound of these boxes and I'm not planning on getting rid of them. This post is heads up for all U15 owners.
I have two pairs, bought at different times, usually using 2 per side, tight packed. A few months back, I noticed one side sounding different than the other. Then one box in particular. Then they just didn't sound all that great like when they were new. Last week I had a show where I was running all four quite hard. On vocal and guitar peaks, I heard significant distortion and thought I had blown a mid driver.
Got home, opened the boxes and all drivers seemed to be OK. Started poking around at the crossover and after a few hours I found a broken lead wire on inductor L7. I had to push on the wire to see this because it still looked connected. What was going on was the higher voltage peaks going through the circuit was arcing across the break, causing the nasty distortion.
I checked all the inductors on the crossover in all four boxes. The results were:
Box 1: 3 breaks, 1 on each end of L7, one on L6.
Box 2: 2 breaks, 1 on L7 and 1 on L6.
Box 3: 1 break on L6.
Box 4: 1 break on L7.
Boxes 1 & 2 have crossover board ver 1.00
Boxes 3 & 4 have crossover board ver 6.00.
That's a 100% failure rate on four boxes. Scary. I re-soldered both ends of L6 and L7 on all four crossovers, then encased the leads in glue. Hope this is not something I need to do regularly.
Karl Bruhn
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| Re: Yorkville U15B problem / heads up [message #348797 is a reply to message #348790 ] |
Fri, 08 August 2008 12:55  |
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I have four also. Thanks for the heads up
Gamma Productions
Live Sound and Lighting
www.gammaprod.com
tate@gammaprod.com
(435) 770-6575
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| Re: Yorkville U15B problem / heads up [message #348821 is a reply to message #348797 ] |
Fri, 08 August 2008 13:35 |
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Which one is the L7 and L6 components?
I've had a cap break off on one of mine and I lost all MF/HF. This was on the circuit board that is attached to the Input panel.
What kind of show where you working with 4 tops and pushing them?
I am planning on running 4 tops in the future. I'm also plan on using 6 UCS1s.
[Updated on: Fri, 08 August 2008 13:36]
I on the web at: meerkatsound.com
I'm a member of the Maryland EV QRx Mafia
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| Re: Yorkville U15B problem / heads up [message #348921 is a reply to message #348851 ] |
Fri, 08 August 2008 19:15 |
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Eric Wong!
Messages: 816
Registered: April 2004
Location: Maryland USA |
Has No Life |
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Wow, unbelievable, I took apart one of the speakers and sure enough. There are breaks.
Thanks for discovering this. Time to bust out the soldering iron. I wonder how they broke??? And I wonder if Yorkville is aware of this.
Also, when you resoldered, did you unscrew the PCB board from the speaker or did you remove the entire plywood base thing that it rests on?
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[Updated on: Fri, 08 August 2008 19:30]
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| Re: Yorkville U15B problem / heads up [message #348934 is a reply to message #348777 ] |
Fri, 08 August 2008 20:45 |
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Bruce Gering
Messages: 582
Registered: April 2004
Location: SE Wisconsin |
Has No Life |
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The problem you describe is caused by excessive vibration combined with heat due to the position and mounting of the xover plate. The good news is that there is a fix for this problem. The guy who can help you the most on this is named Guy Beresford out of Yorkville Canada. Guy has designed a mod to the xover plate to eliminate the excessive vibration which is caused by a direct coupling to the cabinet structure.
Yes, owning 6 U15B's, I've had a few failures over the past couple of years while still under warranty. After the last failure, I called Yorkville to get to the bottom of this. Guy was sooooo helpful! He not only knew exactly the cause of the problem, he had already had a solution worked out! He explained the mod to me over the phone, but after this summer when I don't need all the cabs, I plan on sending in a xover/plate assembly to have him do the mod and also request the needed materials for 5 more. I don't care if I have to pay shipping or for the work/materials (cabs are past warranty), but I'm willing to bet that Yorkville will stand behind their product and I can get the issue taken care of once and for all with little out of pocket.
The breaks you have are in inductance coils that basically act, in conjunction with a resistor, as a filter to help smooth out the rough peaks of the horn, which happen because of the horn flare rate and a bunch of other factors that I am not all that familiar with. Without the filters, certain frequencies will cause resonant distortion in the horn and can lead to diaphragm failure due to the extra energy going to the 1" HF driver.
I hope this helps, and that Yorkville offer a free mod kit with instructions in the near future.
Better to hurry up and wait than to hurry up and late.
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| Re: Yorkville U15B problem / heads up [message #348994 is a reply to message #348984 ] |
Sat, 09 August 2008 01:40 |
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Tony "T" Tissot
Messages: 2393
Registered: June 2006
Location: Northern California |
Has No Life |
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| Tim Padrick wrote on Fri, 08 August 2008 22:41 |
It's great that Yorkville have a (presumed) fix. However IMHO instead of waiting for users to make inquiries, they should have spread the word as soon as they discovered the problem. I'm sure that a lot of U15 users have been doing some head scratching over this for quite some time.
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Or maybe this is the professional community that notices problems first? And helps the manufacturer to promulgate a solution.
ProSoundWeb - Home of 50,000 audio professionals - and two or three curmudgeonly SOBs.
http://www.youtube.com/loshightops
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