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Post by philietes on Apr 11, 2017 18:30:23 GMT
Thank you for the responses. Much appreciated. I have another problem I cannot seem to figure out. My mixer is connected to the Mackie HR824s. No matter at what channel, or volume level there is some quite loud hiss. Too loud for professional use. The strange thing is that the hiss does not change in volume when volume/gain/channel are configured in the mixer. But it does disappear completely when the mixer is connected! How is this even possible? Are my monitors broken? Is it a power supply issue?
I think I could fix it sort of by lowering the gain to 50% in the Mackies, but this is only treatment of symptoms right?
Thanks!
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Post by arnyk on Apr 12, 2017 15:41:56 GMT
Thank you for the responses. Much appreciated. I have another problem I cannot seem to figure out. My mixer is connected to the Mackie HR824s. No matter at what channel, or volume level there is some quite loud hiss. Too loud for professional use. The strange thing is that the hiss does not change in volume when volume/gain/channel are configured in the mixer. But it does disappear completely when the mixer is connected! How is this even possible? Are my monitors broken? Is it a power supply issue? I think I could fix it sort of by lowering the gain to 50% in the Mackies, but this is only treatment of symptoms right? Thanks! You seem to be describing a problem with gain staging. If there is a steady hiss, that is a sign that the gain needs to be reduced some place in the system. Cut the gain until you either can't achieve your preferred maximum operational level at all, or that approaching your preferred maximum level sounds distorted. I often start setting up with all the gain controls centered, and most certainly not maxed out.
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Post by philietes on Apr 12, 2017 23:49:16 GMT
Yes you are right I think. But the Mackie HR824 active monitors recommended setting is max gain though. The gain knobs at the back are imprecise so I would prefer keeping them at the same level (max gain). Since the gain does not change in volume no matter what volume/channel the problem looks to be with the Mackies to me. Strange thing still though that disconnecting the mixer solves the hiss!
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Post by rock on Apr 13, 2017 0:34:04 GMT
Short the input the the Mackie(s) with gain all the way up. How much noise do you hear?
BTW IYDNK, with the input shorted, you will only hear noise generated within the DUT (device under test) i.e. the Mackie(s).
Universal Troubleshooting Tip: Isolate the problem to one stage or section AKA "Divide and Conquer"
Cheers, Rock
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Post by rock on Apr 13, 2017 14:42:34 GMT
Wait a second! What am I talking about???
If you disconnect the mixer and the noise goes away, it's obviously the mixer! Right?
Of course Arny's right, check your gain staging. One way is to start with all your levels at -infinity then bring up the master to unity first. Then, with the channel input shorted, bring up one channel fader to unity or a little below and finally bring the channel input gain up.
Somewhere during the preceding sequence, you may hear the noise get louder, and that's how you'll determine if and where the noise is coming from and it's probably from the input gain stage (make sure your EQ is out or set to zero cause that can generate noise too.)
You can repeat the procedure with a signal plugged into the channel input. When you get to the gain, bring it up so your meters read between -20 and 0 VU depending on how much headroom you like.
Let us know what happens.
Cheers, Rock
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Post by philietes on Apr 14, 2017 10:31:09 GMT
Thanks for the message. Yes well I tried it! But the strange thing is, the volume does not change one bit. Even with master level down all the way, all gains down all the way, EQ at 0, crossfader left or right, switching the active channel, the volume stays the same. Only disconnecting eliminates the hiss. Might be a cable problem then? Interference in some way?
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Post by rock on Apr 14, 2017 12:34:45 GMT
I don't think it's cables; I never heard cables cause hiss. I still think it's the mixer. Can you test the mixer with another powered speaker or power amp/speaker system?
OR can you borrow another mixer or some other signal source like an Ipod to test your Mackies?
Cheers, Rock
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Post by philietes on Apr 14, 2017 15:56:22 GMT
I think you're right. Something shorted in the motherboard perhaps? Unfortunately I cannot test with another system since I do not have the required cables. Will try to do this as soon as possible.
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Post by arnyk on Apr 14, 2017 19:33:54 GMT
Yes you are right I think. But the Mackie HR824 active monitors recommended setting is max gain though. The gain knobs at the back are imprecise so I would prefer keeping them at the same level (max gain). Since the gain does not change in volume no matter what volume/channel the problem looks to be with the Mackies to me. Strange thing still though that disconnecting the mixer solves the hiss! Have you or have you not changed the input gain controls on the Mackie active speakers? If rotating them CCW to say 12 o'clock doesn't change the problem, then they are the problem. To allay your fears, you can leave their gain controls maxed, and obtain the effect of turning them down by inserting devices like these, but try changing the monitor input gain controls first: 10 dB attenuator. 20 dB part, same place, same price
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Post by philietes on Apr 17, 2017 23:14:49 GMT
I now did! The volume does indeed lower. Probably I am in need of a new mixer.
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