Hello All once again

I throw myself on the wisdom of my piers!

I am having series problems with my sound system.....I shall explain......

I currently use two laptops linked into an Alesis Imultimix 8 Mixer unit as separate inputs on channels 5 + 6 and then out through the main mix out into a KAM KXR2000 amplifier.

From the amp left and right channels respectively run 'daisy chained' community MRPII speakers all speakers are connected using speakon connectors and leads.

The connections I use are single jack plugs from the laptop's headphone sockets into 'humm' suppressors for each and then into jack plugs for connection into the mixer. But one one side when I play it through Laptop A then all is well but when I play it through laptop B I get serious Crackling through one pair of the speakers......... usually on the left hand side

HOWEVER. when I connect either laptop up at home to rehearse (I am also a vocalist) I get no such problems although this is only to a very basic off the shelf set up.

So please help me I hope I have explained myself clearly enough I am going out of my mind trying to sort this problem out without throwing money at it and chasing my tail

I ended up last night playing to 350 people through one laptop and my emergency ipod through the imultimix which I'm sure you will agree is far from ideal!

So again any pointers you can give me as to where to start looking will be gratefully received

Hi Tommo

Bit of fault diagnosis required here. What you need to do is set up the entire rig then work backwards. Start with the speakers. Whan you identify which are crackling and which amp channel they are on mark it with some tape or something. Then swap the speaker leads over at the speaker end and see if it still crackles. If it still crackles then its the speaker if the other side crackles then its stage 2. swap the speaker leads completely to rule out the cables. Then swap amp input channels over ( i have had issues with the kam amps when using the jack inputs).

if you find the crackle still there after the above then look at the mixer. try to identify which main mix channel which is sending the crackle then swap the cables over to see if it changes sides at the speakers. mixer faders can be a cause of crackles and give them a good rattle ( amp off of course) to see if this helps. Try diffent channel inputs and ultimately a different mixer if you have access to one.

lastly try swapping the laptop to mixer cables and supressors to rule out the cables etc

if you can run at ful vol

good luck
Dave

Thanks Dave

I'll give it a go, although I'll wait until Monday to run it at full volume!!!!!

I will let you know what happens

Tommo

Right!!!!

I have tried the commetns nd suggestions from earlier in the post from Minty dave and I am pleased to say that I am getting somewhere! Although it's still not right

I swapped the mixer over for a brand new Alesis Unit and got even worse crackle through the left hand channel on the input for channels 5/6 (if you are familiar with the unit you will know which ones I mean!

Went back to my old mixer Hey presto no crackle.......but

When I crank up the volume the left hand channel now cuts out! regardless of which Mixer I am using, I have four speakers all the same and they all do it on the same channel at the same point in the same tune.

I have turned the Amp volume down but it still does it, I have to turn the amp off and on again to get the channel functioning properly, dave you mentioned earlier that you had had issuses with KAM amps in the past was this similiar to the problems you had? if so how did you solve it?

I would like to add for the record that the amp and speakers have been in use for well over two years and I have absolutley no cause for complant about any of the gear I use (Well probably not the brand new mixer but HeyHo!)

So once again any assistanmce is greatfully recieved


Tommo

getting a worse crackle form a brand new mixer is a strange and i would certainly rule out the mixer.



same point in the same tune sounds like the tune itself, does it do it on all tunes?



i had cut out too with intermittent vol loss on channel A when using the jack inputs. i now use the xlr inputs and have never had a repeat problem, also cheap xlr's are unreliable as are cheap mixer xlr outputs. i have a mackie mixer and even that has loose fitting xlr sockets.

if it is the left channel regardless of what you do then i would suspect the amp is faulty. connect up the left channel with 1 speaker only and experiment again by swapping things about to confirm.

regards
dave