SLA Pro - Powered

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Seth
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Re: SLA Pro - Powered

#136 Post by Seth »

Bruce Weldy wrote: Sun Apr 11, 2021 12:34 pm Went back and tried the 2k ohms setting and it showed .001 - so it definitely uses the scale as it rounded up from .8 at the 200 scale to register .001 at the 2k scale......so, it looks like 8 ohms is correct.

Thought I'd try another test. Put on some music and ran it through the Yamaha. I was able to take it all the way to 10 with no problem. Same song, just switched over to the SLA and it crapped out again.

Pretty sure something is wrong in the cab that's cratering the amp.......looking for suggestions. And once again.....it sounds great at lower volumes.
I'm pretty sure (although, I could certainly be wrong) that the DC resistance would/should be less than 4 Ohms... the value of the series resistor in the high pass filter paralleled with the mid drivers.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Re: SLA Pro - Powered

#137 Post by Seth »

What reading do you get if you test the other speaker?
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Re: SLA Pro - Powered

#138 Post by Seth »

Bruce Weldy wrote: Sun Apr 11, 2021 12:34 pm Went back and tried the 2k ohms setting and it showed .001 - so it definitely uses the scale as it rounded up from .8 at the 200 scale to register .001 at the 2k scale......so, it looks like 8 ohms is correct.
I'm fairly certain you're reading a little less than 1 ohm. 0.001 kOhm is 1 ohm
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Re: SLA Pro - Powered

#139 Post by Seth »

Shot in the dark guess is the Capacitor is faulty.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: SLA Pro - Powered

#140 Post by Bruce Weldy »

Seth wrote: Sun Apr 11, 2021 12:50 pm What reading do you get if you test the other speaker?

Dammit Seth, would you quit asking intelligent, pertinent questions?


It tested out at 6.5 - so, you are right. So, I guess that means that somehow I'm getting a really low impedance from the speaker array.

Damn, it's gonna' be a PITA to take the amp out so I can get to the high pass filter to be able to test the speakers without the filter engaged to see what they say. Then I can test the tweeter array and see what it is....

Not sure that will happen today . The Masters is finishing up and after three gigs in three nights - I plan to watch/nap through the golf tournament.

Seth, thanks for telling me to do the things I should have already done myself.....I'm usually better than this at trouble shooting. Geez......

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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Bill Fitzmaurice
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Re: SLA Pro - Powered

#141 Post by Bill Fitzmaurice »

It does point to a too low impedance load, but I don't see how that could be. I don't recall how you're running it and don't want to search the entire thread, is it bi-amping just the SLA? If it's the tweeter high pass at fault one explanation is if the 30 ohm resistor isn't connected at one end. Without that connected at both ends the filter would present about a 1 ohm load to the amp at 5kHz.

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Seth
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Re: SLA Pro - Powered

#142 Post by Seth »

Bruce Weldy wrote: Sun Apr 11, 2021 1:04 pm
Seth wrote: Sun Apr 11, 2021 12:50 pm What reading do you get if you test the other speaker?

Dammit Seth, would you quit asking intelligent, pertinent questions?


It tested out at 6.5 - so, you are right. So, I guess that means that somehow I'm getting a really low impedance from the speaker array.

Damn, it's gonna' be a PITA to take the amp out so I can get to the high pass filter to be able to test the speakers without the filter engaged to see what they say. Then I can test the tweeter array and see what it is....

Not sure that will happen today . The Masters is finishing up and after three gigs in three nights - I plan to watch/nap through the golf tournament.

Seth, thanks for telling me to do the things I should have already done myself.....I'm usually better than this at trouble shooting. Geez......
Just pull the bottom driver...

Image
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Re: SLA Pro - Powered

#143 Post by Bill Fitzmaurice »

That picture seems to show the coil connected to the wrong end of the cap.

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Seth
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Re: SLA Pro - Powered

#144 Post by Seth »

Bruce Weldy wrote: Sun Apr 11, 2021 1:04 pm Seth, thanks for telling me to do the things I should have already done myself.....I'm usually better than this at trouble shooting. Geez......
I get the same way when it's my own problem, yet I'm dialed in when it's solving other peoples problems. It's a really weird thing. Glad to know I'm not the only one!
Bill Fitzmaurice wrote: Sun Apr 11, 2021 1:05 pm It does point to a too low impedance load, but I don't see how that could be. I don't recall how you're running it and don't want to search the entire thread, is it bi-amping just the SLA? If it's the tweeter high pass at fault one explanation is if the 30 ohm resistor isn't connected at one end. Without that connected at both ends the filter would present about a 1 ohm load to the amp at 5kHz.
He's just using the full range channel in the amp. The high frequency amp output is not being utilized.

Everything appears to be in order.
IMG_3296.JPG
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Location: Sacramento, California, USA
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Re: SLA Pro - Powered

#145 Post by Seth »

Actually... the coil is on the wrong side of the capacitor, isn't it? Looks to me, that could very well be the issue.
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Seth
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Location: Sacramento, California, USA
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Re: SLA Pro - Powered

#146 Post by Seth »

Image
Screenshot (102).png
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

User avatar
Seth
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Location: Sacramento, California, USA
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Re: SLA Pro - Powered

#147 Post by Seth »

Bill Fitzmaurice wrote: Sun Apr 11, 2021 1:25 pm That picture seems to show the coil connected to the wrong end of the cap.
Hah! Missed this post. :thumbsup:
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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Bill Fitzmaurice
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Re: SLA Pro - Powered

#148 Post by Bill Fitzmaurice »

I've lost track of who's cab that is, but if the coil is connected to the input side of the cap it's a miracle that it works at all.

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Seth
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Re: SLA Pro - Powered

#149 Post by Seth »

Hear that Bruce?... you're miraculous!
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: SLA Pro - Powered

#150 Post by Bruce Weldy »

Bill Fitzmaurice wrote: Sun Apr 11, 2021 1:54 pm I've lost track of who's cab that is, but if the coil is connected to the input side of the cap it's a miracle that it works at all.
That's mine and it indeed looks like the coil is on the wrong side of the cap......how the hell did I do that?

Starting to feel like a real newb.......

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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