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Author Topic: 725 tweeter  (Read 3718 times)

Bob Kidd

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725 tweeter
« on: August 30, 2015, 12:43:22 PM »

During gig Thursday night tech reversed connections sending lows to 725 and highs to 728. They did catch it during sound check and corrected. I got back in town yesterday and turned on systemaand tweeter not there. Hit side of speaker and it came back on. Checked connections to tweeter and it seemed fine. Was pressed for time so I could not go further in checking connection to crossover. GM at venue mention he heard loud distortion prior to it getting corrected. It was a very Loud rock show. When tweeter comes on it sounds fine just doesn't stay in. Any ideas?
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Ivan Beaver

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Re: 725 tweeter
« Reply #1 on: August 30, 2015, 01:10:32 PM »

During gig Thursday night tech reversed connections sending lows to 725 and highs to 728. They did catch it during sound check and corrected. I got back in town yesterday and turned on systemaand tweeter not there. Hit side of speaker and it came back on. Checked connections to tweeter and it seemed fine. Was pressed for time so I could not go further in checking connection to crossover. GM at venue mention he heard loud distortion prior to it getting corrected. It was a very Loud rock show. When tweeter comes on it sounds fine just doesn't stay in. Any ideas?
There is simply a loose connection somewhere.

That could also be the cause of the distortion.

The connection could be in the driver itself-the crossover etc.

You need to take it apart and "wiggle, bang and bump" until you narrow down where the problem is, then fix it.
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Bob Leonard

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Re: 725 tweeter
« Reply #2 on: August 30, 2015, 05:18:22 PM »

Do as Ivan suggests, and if you find it is actually a bad diaphragm call Pro Sound service and talk to Charlie Tappa. Make sure you're sitting down when you hear the price, and please don't substitute Chinese shit for the real deal.
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Scott Carneval

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Re: 725 tweeter
« Reply #3 on: August 31, 2015, 04:30:19 PM »

During gig Thursday night tech reversed connections sending lows to 725 and highs to 728. They did catch it during sound check and corrected. I got back in town yesterday and turned on systemaand tweeter not there. Hit side of speaker and it came back on. Checked connections to tweeter and it seemed fine. Was pressed for time so I could not go further in checking connection to crossover. GM at venue mention he heard loud distortion prior to it getting corrected. It was a very Loud rock show. When tweeter comes on it sounds fine just doesn't stay in. Any ideas?

Sounds like it might just be a coincidence.  Even with the cables reversed, the internal crossover in the 725 would have still routed all of the LF content to the 15's and not to the compression driver.  You might have damaged the crossover, but it's odd that it works intermittently. 
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Ray Aberle

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Re: 725 tweeter
« Reply #4 on: August 31, 2015, 05:10:55 PM »

Sounds like it might just be a coincidence.  Even with the cables reversed, the internal crossover in the 725 would have still routed all of the LF content to the 15's and not to the compression driver.  You might have damaged the crossover, but it's odd that it works intermittently.

The internal crossover is for running a passive connection. Sounds like they are running them bi-amped, which means the 725 is looking for LF content on pins 1 and HF content on pins 2. If you reverse those, you can send the LF signal/power directly to the HF subsystem...

-Ray
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Bob Kidd

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Re: 725 tweeter
« Reply #5 on: August 31, 2015, 05:34:07 PM »

The internal crossover is for running a passive connection. Sounds like they are running them bi-amped, which means the 725 is looking for LF content on pins 1 and HF content on pins 2. If you reverse those, you can send the LF signal/power directly to the HF subsystem...

-Ray

Hi Ray, not running bi-amped. Tested tweeter in different box and it us fine. Put another tweeter inpproblem box and for the first 5 seconds no tweeter then it popped on. Hit side of box, moved it and it stayed on. I did however noticed when I moved or hit side of box a bit of distortion. I checked all connections and seemed to be fine. I would assume either all connections may nned contact spray, or crossover is going bad, or issue with back panel. 
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Ray Aberle

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Re: 725 tweeter
« Reply #6 on: August 31, 2015, 07:44:24 PM »

Ohhh that would have required me to recognize the difference between 725s and 728s in your OP versus me thinking that you were bi-amping the tops and THOSE were the cables mis-patched; an LF and an HF line. Sowwy.

Something loose is a good suggestion at this point-- now that I don't sound like an idiot (as much) I would agree with Scott's thought process that swapping the feeds shouldn't make any difference.

With that said, for future things… try running an NL4 to each side, sending subs on pins 2 and tops on pins 1. Input into sub, chain out to tops. Set subs to pins 2. That way, there's no "connecting backwards" possible, reduces your cable runs, and might speed up setup time a bit. (The jump to the tops can be 2cond or 4cond; there is no need for 4cond cable though. The 2cond will take care of the signal for the tops, which is still coming through pins 1.)

-Ray
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Bob Leonard

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Re: 725 tweeter
« Reply #7 on: August 31, 2015, 08:16:03 PM »

Hi Ray, not running bi-amped. Tested tweeter in different box and it us fine. Put another tweeter inpproblem box and for the first 5 seconds no tweeter then it popped on. Hit side of box, moved it and it stayed on. I did however noticed when I moved or hit side of box a bit of distortion. I checked all connections and seemed to be fine. I would assume either all connections may nned contact spray, or crossover is going bad, or issue with back panel. 

Bob,
Take out the crossover and re-solder every connection. What you're describing is common to a cold solder joint.
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Mike Monte

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Re: 725 tweeter
« Reply #8 on: August 31, 2015, 10:15:34 PM »

Bob,
Take out the crossover and re-solder every connection. What you're describing is common to a cold solder joint.

I just went through the same symptoms with a horn in one of my yorkville e152 cabs.  Intermittent horn.

I tried contact cleaner, disconnecting/reconnecting everything that wasn't soldered, wiggled/pried soldered connections, all seemed to be in place...etc.  I finally brought it to a tech and he resoldered the connections on the crossover = problem solved. 
He told me that sometimes the solder joints can look good but be a bad connection.

Mike M
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Chris Hindle

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Re: 725 tweeter
« Reply #9 on: September 01, 2015, 01:25:32 AM »

I just went through the same symptoms with a horn in one of my yorkville e152 cabs.  Intermittent horn.

I tried contact cleaner, disconnecting/reconnecting everything that wasn't soldered, wiggled/pried soldered connections, all seemed to be in place...etc.  I finally brought it to a tech and he resoldered the connections on the crossover = problem solved. 
He told me that sometimes the solder joints can look good but be a bad connection.

Mike M
last century I bought a used TDM. On the bench, before plugging it into the monitor rack, it was intermittent. Popped the top, and found channel 2 XLR's weren't soldered to the PCB. Can anyone say "last box build on a Friday night ?"  or "First one off the assembly line, Monday AM ?"
Chris.
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ProSoundWeb Community

Re: 725 tweeter
« Reply #9 on: September 01, 2015, 01:25:32 AM »


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