Hooking up to PA power amp, and failing !

Spittbubble

New Member
I just purchased an AX8 , and I’m trying to connect it to a PA power amp , hooked to a PA speaker , and can’t seem to get sound . I’m obviously doing something wrong . Any advise would be appropriated .
 
Using an xlr cable , I went out to power amp , then Connected power amp to JBL speaker , then plugged my guitar into AX8 . Getting nothing for sound .
 
Using an xlr cable , I went out to power amp , then Connected power amp to JBL speaker , then plugged my guitar into AX8 . Getting nothing for sound .
is the power amp on?
is the power amp volume knob turned up for the correct input channel?
does the cable from the power amp to the Speaker work?
is the AX8 Output 1 knob turned up?
is a working Preset loaded on the AX8?
does the XLR cable work?
is your guitar volume up?
does the guitar cable work?
 
All very good questions , all cables are brand new , all appropriate volumes are up , I borrowed the power amp and the speaker , I’m sure the power amp is working , but I’m not 100 % sure that the speaker is working , will have to try another speaker tonight . I just want to make sure that I’m hooking it up properly , and then I can trouble shoot from there
 
All very good questions , all cables are brand new , all appropriate volumes are up , I borrowed the power amp and the speaker , I’m sure the power amp is working , but I’m not 100 % sure that the speaker is working , will have to try another speaker tonight . I just want to make sure that I’m hooking it up properly , and then I can trouble shoot from there
from what you've said so far, it appears to be setup correctly. it's pretty straight forward.

i can't confirm you're connecting the Power amp to speaker correctly. using a speaker cable and not a regular instrument cable?

what specific power amp model and jbl speaker model?
 
The connection from power amp to speaker is a speaker cable that I purchased yesterday , that’s new to me , it’s similar to an xlr but different .the power amp is a QSC RMX 850 and the speaker is a JBL sound factor sf12m
 
The connection from power amp to speaker is a speaker cable that I purchased yesterday , that’s new to me , it’s similar to an xlr but different .the power amp is a QSC RMX 850 and the speaker is a JBL sound factor sf12m
you're probably using Speakon connectors. they lock with a small twist. very common these days.

the speaker seems to be discontinued, so i'm assuming you bought used? i could see that being the thing not working. but keep us updated. again, it sounds like you have it connected correctly, assuming all volumes are up and a preset that works is being used.
 
They are speaking cables , and fortunately, I’ve only borrowed these items just to start to get a feel for what I’m dealing with here . Thank you so much for the feedback Chris ./
 
You can also use normal 1/4 inch jack speaker cables into Speakon sockets - just plug it in the centre hole ..... so if you can lay your hands on one of those - it's just a 2 core non screened cable with normal mono tip/sleeve jacks on each side.

Or even a normal instrument cable would do for testing as long as the distance between amp and cab isn't too long - a 10 or 15 ft cable should be enough to test the amp out/cab in at least.

Obviously you'll need to use the 1/4 inch line outs on your AX8 if doing this.

I once had an issue with a Speakon output socket when using a male speakon ended cable - it cured itself after I tried plugging in a normal jack cable (which worked) and tried the speakon again afterwards. Think it was just some impingement in the female socket that was obstructing the speakon male socket from connecting cleanly and putting in the jack 'lined things up' again. It was a brand new power amp so the socket had never been used before.

Even with no signal going in to the amp, when you turn up the inputs on it full you should hear a bit of hiss/hum from the speaker if the cable is good.
 
You can also use normal 1/4 inch jack speaker cables into Speakon sockets - just plug it in the centre hole
???? really? i didn't know that.

i don't think this is true for every Speakon jack. a quick search shows that some don't have this capability.
 
You can also use normal 1/4 inch jack speaker cables into Speakon sockets - just plug it in the centre hole ..... so if you can lay your hands on one of those - it's just a 2 core non screened cable with normal mono tip/sleeve jacks on each side.

Or even a normal instrument cable would do for testing as long as the distance between amp and cab isn't too long - a 10 or 15 ft cable should be enough to test the amp out/cab in at least.

Obviously you'll need to use the 1/4 inch line outs on your AX8 if doing this.

I once had an issue with a Speakon output socket when using a male speakon ended cable - it cured itself after I tried plugging in a normal jack cable (which worked) and tried the speakon again afterwards. Think it was just some impingement in the female socket that was obstructing the speakon male socket from connecting cleanly and putting in the jack 'lined things up' again. It was a brand new power amp so the socket had never been used before.

Even with no signal going in to the amp, when you turn up the inputs on it full you should hear a bit of hiss/hum from the speaker if the cable is good.
Great information Maxdown , I had no idea that was possible. I’ll try that tonight. I’m wondering if I can go straight to my Marshall cabinet from the power amp as well ?
 
???? really? i didn't know that.

i don't think this is true for every Speakon jack. a quick search shows that some don't have this capability.
Worked for me on one of my Matrix GT1000FX Speakon outputs after I got it new. Maybe some speakon sockets don't? It does take the full length of the jack before it 'clicks' into place on the Matrix or my speakon outs I have on my front breakout panel.

Even just sticking a 1/4 inch jack in and turning it a bit - then try the Speakon again might do the job - it seemed that did it for me regardless of whether signal works or not for you with 1/4 jack cable.
 
I’m wondering if I can go straight to my Marshall cabinet from the power amp as well ?
a power amp can power a guitar cab, yes.

Worked for me on one of my Matrix GT1000FX Speakon outputs after I got it new. Maybe some speakon sockets don't? It does take the full length of the jack before it 'clicks' into place on the Matrix or my speakon outs I have on my front breakout panel.

Even just sticking a 1/4 inch jack in and turning it a bit - then try the Speakon again might do the job - it seemed that did it for me regardless of whether signal works or not for you with 1/4 jack cable.
cool. i know this wasn't a feature of Speakon when it was first being implemented. jeez i'm not even that old haha. i'm a fan of combination jacks whenever possible.
 
Not all Speakon connectors will accept 1/4” speaker plug. The first Speakon connectors I saw that would accept a 1/4” plug were green in color to differentiate them from the regular black connectors. Hopefully the amp has info on it about the connector.
 
The first time I saw those combo Speakon 1/4" was on my new Matrix amp. No amp I ever used prior had the 1/4" hole in the center of the Speakon. Great idea though.

OP: assuming it's a normal Speakon, push the plug all the way in (it's 'keyed' so it can only go in when lined up properly) and then twist it clockwise until it clicks into place. That makes the connection and locks it in place. To remove, pull back on the silver release tab (to unlock), then twist counter-clockwise while pulling. The plug will rotate inside the jack about 1/8th of a turn.

If I had to guess, I'm assuming you just pushed the plug in (like a 1/4") and didn't know you had to twist/lock. Amirite?
 
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