Speaker Fault

[le freak 1]

hi all , i have a couple of 15" 800w active alto speakers , the last 2 discos i have done have had the same problem... after an hour into the gig the speakers suddenly lose all treble and sound muffled and horrible, if you turn it down the good sound comes back again after about 20 seconds, i only have the speaker knob on back at 25% power so im not blasting them..... scares me every time. any ideas what it could be ? cheers for any help , jason

[McCardle 1]

This happens on both L & R speakers at the same time?

[le freak 1]

... you know its hard to tell , it defo sound like it but maybe it just happening to one sounds like its both when your behind the speakers ? ..... can it happen to both if its defo not the mixer or cd players as i changed both and it still happens , cheers j

 

 

This happens on both L & R speakers at the same time?

 

[McCardle 1]

I'd check this out if you can. As you know the two speakers are entirely independent units and the odds for both to fail, with the same fault, at exactly the same time must be huge , so I would think that its probably just one speaker which has the fault, and its just room acoustics which makes it sound like its both.

 

Are you using reasonable quality, screened cables to connect the speakers from the Mixer?

 

I believe that each of these speakers have two individual internal amplifiers, one of them drives the LF driver (Bass) the other smaller one, drives the HF (Treble) driver, I suspect that the problem either lies with a dry joint on the HF amplifier circuit board, or more likely a component overheating, given your description.

 

Are the speakers still under warranty?.

Edited October 26, 2013 by McCardle

[le freak 1]

Cables are good , got 4 year warranty with dv247 so should be ok for a return .cheers for help.

 

It scared me that much I'm gonna get rid of the 15" bass bin and get a spare speaker instead (what i can fit in car reasons) , never want to go through that feeling again ....gut wrenching.

 

Can I ask u what setting do you have your gear on ? Ie speaker volume knob on back , master on djm600 mixer and volume slider. Should the volume knob on back of speaker be as low as you can get away with ? Right now my speakers are on quarter strength ,master on mixer at no1 ( of 10 ) and Channel sliders full way up .

 

Cheers again . Jason

 

 

I'd check this out if you can. As you know the two speakers are entirely independent units and the odds for both to fail, with the same fault, at exactly the same time must be huge , so I would think that its probably just one speaker which has the fault, and its just room acoustics which makes it sound like its both.

 

Are you using reasonable quality, screened cables to connect the speakers from the Mixer?

 

I believe that each of these speakers have two individual internal amplifiers, one of them drives the LF driver (Bass) the other smaller one, drives the HF (Treble) driver, I suspect that the problem either lies with a dry joint on the HF amplifier circuit board, or more likely a component overheating, given your description.

 

Are the speakers still under warranty?.

 

[fester 0]

Can I ask u what setting do you have your gear on ? Ie speaker volume knob on back , master on djm600 mixer and volume slider. Should the volume knob on back of speaker be as low as you can get away with ? Right now my speakers are on quarter strength ,master on mixer at no1 ( of 10 ) and Channel sliders full way up .

Cheers again . Jason

 

I don't think your speakers are set high enough.

Your speakers should be set to 0db. Most active speakers have a 0db level on the "power" (gain) control but the alto doesn't seem to have that marking as far as I can see. I'm going to take an educated guess that it's at the 12 o'clock / 50% mark.

If you run your speakers too low you have to shove in more signal from your mixer to achieve the desired volume. If the signal to the speakers is too hot you are likely overdriving the speakers amps which leads to clipping and overheating. You turn down the speakers, they cool down and start working again.

By turning up the gain on the speakers you don't have to put in as much signal to achieve the volume and the speakers actually run more efficiently and cooler.

[le freak 1]

cheers fester , i should of said i had it at the half way position 0db to start with, its when it started its muffled sound that i turned it down.

should the mixer master be high with the channel volume sliders low or should the mixer master be low with the channel volumes high for best results

 

 

I don't think your speakers are set high enough.

Your speakers should be set to 0db. Most active speakers have a 0db level on the "power" (gain) control but the alto doesn't seem to have that marking as far as I can see. I'm going to take an educated guess that it's at the 12 o'clock / 50% mark.

If you run your speakers too low you have to shove in more signal from your mixer to achieve the desired volume. If the signal to the speakers is too hot you are likely overdriving the speakers amps which leads to clipping and overheating. You turn down the speakers, they cool down and start working again.

By turning up the gain on the speakers you don't have to put in as much signal to achieve the volume and the speakers actually run more efficiently and cooler.

 

[superstardeejay 0]

shove the channel faders all the way up if you want, adjust the channel gains so the channel PFL meters are tickling red, then adjust the master to taste, avoiding the red on the master VU.

Bear in mind the DJM600 also has a rear attenuator after the master fader, if in doubt, turn this all the way up for maximum leeway on the master.

Worst thing you can do is have the speaker gains too low and then try and 'force' level through by over-driving the mixer. Normally a powered speaker will have a centre detent on the gain to indicate 0dB.

 

 

 

 

 

[le freak 1]

Cheers for the advice and help , will give the settings a go, cheers j

 

shove the channel faders all the way up if you want, adjust the channel gains so the channel PFL meters are tickling red, then adjust the master to taste, avoiding the red on the master VU.

Bear in mind the DJM600 also has a rear attenuator after the master fader, if in doubt, turn this all the way up for maximum leeway on the master.

Worst thing you can do is have the speaker gains too low and then try and 'force' level through by over-driving the mixer. Normally a powered speaker will have a centre detent on the gain to indicate 0dB.