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Gain & Impedance ?


Active Member
Jul 3, 2018

I have a question that I am not that familiar with and need some help.

I have a buddy of mine who is a Principle of a School and they have gotten some new equipment for their Auditorium recently and it's pro audio gear and I'm looking to help out a bit like running wires and that kinda off stuff and racking in equipment generally setting it up.

Ok with that said I noticed in manual that the amp has like 3 or so different input gain settings and each of the 4 channels have a PRX412m jbl 8ohm speaker hooked to each one . They also have a beheringer xr18 as their mixer. I guess I'm looking what would be the best gain option to set the amp input at to match the mixer output correctly and the best overall settings for those speakers.

These are the specs. Any help would be great. They will have a big end of school year show and graduation coming up so I am hoping to get it setup the proper way by then so have a nice show .

These will be connected via xlr from mixer to amp direct.

Beheringer xr18

Output Characteristics

Output impedance, XLR, unbal. / bal. 50 Ω / 50 Ω 50 Ω / 50 Ω
Output level, XLR, nom./max. +4 dBu / +16 dBu +4 dBu / +16 dBu
Output impedance, TRS, unbal. / bal. 50 Ω / 50 Ω 50 Ω / 50 Ω
Output level, TRS, nom./max. +4 dBu / +16 dBu +4 dBu / +16 dBu
Output impedance, RCA 1 kΩ —
Output level, RCA, nom./max. +4 dBu / +16 dBu

This is the amp.

Crown Audio CDi 4|600 4-Channel DriveCore Series Power Amplifier (600W)​

The gain input options are +26dbu. +34dbu and +37 dbu

Input SensitivityLine:
0.7 Vrms to 2.5 Vrms / -.8 dBu to 10.2 dBu (at 8 Ohms)
1 Vrms to 3.5 Vrms / 2.2 dBu to 13.2 dBu (at 70 V)
1.4 Vrms to 5 Vrms / 5.2 dBu to 16.2 dBu (at 100 V)Input Impedance10 Kilohms (Balanced)
5 Kilohms (Unbalanced)Max Gain34 dB (at 4 Ohms, at 8 Ohms, at 70 V, at 100 V)Max Input Level+20 dBu

Thanks for any and all help in advance.


Addicted to Fun and Learning
Forum Donor
Aug 27, 2018
can a Gort remove this duplicate thread?
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