Airbornegary
I need some help from a sound tech.
System:
Yamaha MG12/4FX Mixing Board
Yamaha BR15 Speakers x2
Yamaha MSR800W Sub
QSC RMX2450 Amp
I have two problems right now:
1. I connect my laptop or CD+G player to channels 9-10 and 11-12. When I push PFL to listen in the headphones the level meter peaks out. If PFL is not active the the level is green. This even happens with an IPOD or headphone jack from my laptop is connected. I am attaching a link to the mixer users manual so you can see the specs of each channel. I have not tried using the phone jacks in channel 5-6 and 7-8 yet. Please take a look at the manual to see all the specs - I have no idea what all of the numbers mean in there.
http://www2.yamaha.co.jp/manual/pdf/pa/english/mixers/mg12_4fxe.pdf
2. This has only happened one time so far. I was in the middle of a set when my mains went silent but the sub kept pumping. I run my wires out of mixer ST out into the sub (powered sub with through puts), out of sub to amp, out of amp to mains. The amp never clipped once. The only thing I can think of is the amp overheated and went into a cool down. Total sound returned in about 20 seconds (seemed like a lifetime) My amp is in a gator rack with wireless mic and CD+G player and mixer on top. I had the back of the case on but has a 3" hole in it. The amp sucks air back to front. This only happened once after I connected the sub but it's an active sub with no strain on the amp. Could heat be a problem? Thoughts.
I know this may sound confusing to most but you experienced sound techs I am sure you know what the problem is. Thanks for the help!
System:
Yamaha MG12/4FX Mixing Board
Yamaha BR15 Speakers x2
Yamaha MSR800W Sub
QSC RMX2450 Amp
I have two problems right now:
1. I connect my laptop or CD+G player to channels 9-10 and 11-12. When I push PFL to listen in the headphones the level meter peaks out. If PFL is not active the the level is green. This even happens with an IPOD or headphone jack from my laptop is connected. I am attaching a link to the mixer users manual so you can see the specs of each channel. I have not tried using the phone jacks in channel 5-6 and 7-8 yet. Please take a look at the manual to see all the specs - I have no idea what all of the numbers mean in there.
http://www2.yamaha.co.jp/manual/pdf/pa/english/mixers/mg12_4fxe.pdf
2. This has only happened one time so far. I was in the middle of a set when my mains went silent but the sub kept pumping. I run my wires out of mixer ST out into the sub (powered sub with through puts), out of sub to amp, out of amp to mains. The amp never clipped once. The only thing I can think of is the amp overheated and went into a cool down. Total sound returned in about 20 seconds (seemed like a lifetime) My amp is in a gator rack with wireless mic and CD+G player and mixer on top. I had the back of the case on but has a 3" hole in it. The amp sucks air back to front. This only happened once after I connected the sub but it's an active sub with no strain on the amp. Could heat be a problem? Thoughts.
I know this may sound confusing to most but you experienced sound techs I am sure you know what the problem is. Thanks for the help!
Mensajes Mon 18 May 09 @ 8:30 am
cstoll
Airbornegary wrote :
1. I connect my laptop or CD+G player to channels 9-10 and 11-12. When I push PFL to listen in the headphones the level meter peaks out. If PFL is not active the the level is green. This even happens with an IPOD or headphone jack from my laptop is connected. I am attaching a link to the mixer users manual so you can see the specs of each channel. I have not tried using the phone jacks in channel 5-6 and 7-8 yet. Please take a look at the manual to see all the specs - I have no idea what all of the numbers mean in there.
Well without getting to technical, you are using the correct channels of available channels on that console for what you are doing. And when you PFL a channel on a mix console, the gain level is displayed on the VU meters.
Now the technical, what you are describing is that you are seeing the peak of the Gain for those channels. The problem is you have a lot of Gain and no way to reduce it on those channels (no gain control knobs). Those channels are designed for commercial gear that has a nominal output of -10dBu (as marked on the input points on the back). I would check your CD+G player specs and see if what the output rating is? It should be +4dBV or -10dBu. From what you describe, I suspect +4dBV. See if there is a switch on the CD+G unit to change the output type?
Are you having to run the faders for those channels around -10 or below to get a level balance on the Master Out when comparing fader levels for things on the other channels?
And since you can't control the input Gain on those channels then I would consider moving them to 5/6 and 7/8 where you can dial down the gain. To much constant Gain (especially clipping/peaking) into a channel can degrade and damage the channel.
Airbornegary wrote :
2. This has only happened one time so far. I was in the middle of a set when my mains went silent but the sub kept pumping. I run my wires out of mixer ST out into the sub (powered sub with through puts), out of sub to amp, out of amp to mains. The amp never clipped once. The only thing I can think of is the amp overheated and went into a cool down. Total sound returned in about 20 seconds (seemed like a lifetime) My amp is in a gator rack with wireless mic and CD+G player and mixer on top. I had the back of the case on but has a 3" hole in it. The amp sucks air back to front. This only happened once after I connected the sub but it's an active sub with no strain on the amp. Could heat be a problem? Thoughts.
I looked at the specs of the Amp, and notice that it has an OUTPUT option. I would use that instead of the THRU connections. Look at Yamaha's own recommendation of setup for this Sub when using an external amp after the sub - Page 6. [ http://www2.yamaha.co.jp/manual/pdf/pa/english/speakers/msr800w_en.pdf ]
Also, on the QSC amp look at your DIP switch settings, I would suggest that you use the LF 30Hz settings with the LF Filter ON, the Yamaha is already doing a 100Hz Filter on the OUTPUTs, so you don't want the 50Hz setting on the QSC as it adds a boost of gain above 0dB at 100Hz - the 30Hz option doesn't do this. Also, not sure what type of speakers you are pushing with the QSC, but if the amp is overheating then I would pull back the GAIN output on the QSC and Yamaha Sub and push a bit stronger signal to the speakers from the mixer.
There are still a few unknowns based on what you have given that makes it difficult to give you more direct answers.
I would look into a nice signal processor like the Aphex 204 [ www.aphex.com/204.htm ] (around a $250) that will greatly enrich the sound and not require you to push the system as hard.
Hope this helps ...
Mensajes Mon 18 May 09 @ 10:09 am
Airbornegary
cstoll, Thanks for the reply.
As far as the mixer is concerned, I can have the channel fader all the down and the line still peaks. The CD+G player has no switch for output and will have to check the output when I get home later. From my laptop I can turn down the master output in the program I use and can control the channel level from there and control mixer output levels somewhat from that. I will try channels 5/6 and 7/8 so I can control the gain on the mixer itself.
Amp: I have set up my mains and sub according to what yamaha says. I even emailed yamaha to make sure this was correct. Both mixer ST out to powered sub throughputs, out of powered sub to amp input (smae as I would connect mixer), out of amp to passive yamaha BR15 speakers (x2). I will check the dip switches on the amp when I get home tonite. I never made a change when I added the powered sub since I didn't think it was necessary. Maybe it is. There is more than enough power in the amp to push the BR15s (400W RMS and 800 Peak).
Please let me know what other info you need for more clarity. Thanks!
As far as the mixer is concerned, I can have the channel fader all the down and the line still peaks. The CD+G player has no switch for output and will have to check the output when I get home later. From my laptop I can turn down the master output in the program I use and can control the channel level from there and control mixer output levels somewhat from that. I will try channels 5/6 and 7/8 so I can control the gain on the mixer itself.
Amp: I have set up my mains and sub according to what yamaha says. I even emailed yamaha to make sure this was correct. Both mixer ST out to powered sub throughputs, out of powered sub to amp input (smae as I would connect mixer), out of amp to passive yamaha BR15 speakers (x2). I will check the dip switches on the amp when I get home tonite. I never made a change when I added the powered sub since I didn't think it was necessary. Maybe it is. There is more than enough power in the amp to push the BR15s (400W RMS and 800 Peak).
Please let me know what other info you need for more clarity. Thanks!
Mensajes Mon 18 May 09 @ 8:22 pm