# very weak sub output level with mini dsp



## apilon (May 18, 2006)

Good morning 

hope you can help me out for a moment here 

I built a micro marty box that i outfitted with a TC Sounds LMR-R15 driver that i had. 

here how i connected everything :

from Anthem MRX300 sub out rca to inputt1 of minidsp 2 X 4 balanced with cutout end connected to positive and shield with a small wire jumping the shield and negative input 

Mini dsp output ( positive, negative, shield) to xlr input of ep4000 

speakon connection output 1 (rewire for bridge mode ) to speakon input of micro marty 

i am using 2 way advanced 2.1 plugin which i configured with lpf bypass and hpf to 23hz butterworth 12db 

upon testing sub level out is very weak measured at 64 db with radio shack meter. 

I removed the mini dsp and connected a rca to xlr cable directly to anthem sub out to ep4000 , i was no getting any sound 

i tried the same thing with a rca to 1/4 plug sub level output was reaching 76db 

Tried same test with a QSC rmx850 same result 

So i am basically pulling the few remaining hair i have on my head trying to figure out what is wrong 

Please help 


Alain


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## Wayne A. Pflughaupt (Apr 13, 2006)

Is 76 dB good or bad?

Regards, 
Wayne


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## RTS100x5 (Sep 12, 2009)

your HPF is 23hz ???


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## apilon (May 18, 2006)

Wayne A. Pflughaupt said:


> Is 76 dB good or bad?
> 
> Regards,
> Wayne


I don't know guess it is ......., at 64 it was not but i found the problem. The jumper inside the minidsp unit was set to 2 vrsm i moved it to 0.9 and it solved the low output problem 

Gain structure is such a mystery 

Alain


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## apilon (May 18, 2006)

RTS100x5 said:


> your HPF is 23hz ???


Hi 

Yes the microcube box design call a a hpf of 23hz as per this FAQ 

http://www.avsforum.com/forum/155-diy-speakers-subs/1648673-martysub-faq.html


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