Hello dear folks.
I recently added 2 subwoofers to my 2².0 system.
I use MiniDSP 2x4 HD as the center of this system, (connected to my desktop computer, as the source). I run 2 sets of speakers (the ² in 2.²) from it to a vintage stereo amp.
The newly added subwoofers were first connected to the MiniDSP 2x4 HD outputs, which produced sound loud enough, I had to dial the LEVEL knob on the SUBs no higher than 1, or 2 to match the volume to the other speakers, and then, I would fine tune volume digitally through DSP software from MiniDSP.
I remembered I had a MOTU M4 lying around not being used, so I decided to add it to the system, just so that I could have a physical volume control for the SUBs.
So now, I’m feeding audio signal from MiniDSP 2x4 HD to MOTU M4 to SUBs. After doing this, subwoofer’s volume was reduced drastically, and the LEVEL knob now has to be at 50% on the SUBs amp.
So whatever fuckery (signal processing) the MOTU M4 is doing to my signal, it is bringing the gain way down, and now I’m afraid that I could blow up my SUBs if the digital outputs were ever to get crazy and increase for reasons unknown.
Could some one help me understand what is happening, and how to increase the signal’s volume from the MOTU M4 to the SUBs without having to keep the gain levels so high on the DSP’s outputs?
Or am I worrying for no reason? Thanks in advance…
The outputs 3-4 on the M4 do not work with the volume dial and need to be adjusted in whatever OS you are running.
It’s a really dumb system flaw that those outputs are not directly controllable on the hardware.
Was just thinking. Cant you just use OS volume control and not needing to manually adjust the volume nub, could just not use the Motu M4 ?
Is there a reason subs need more or less volume in some situations and why manual adjustment is needed?
I just wasn’t expecting such a significant drop in gain output when running the signal through the M4.
I can always control source volume digitally on whatever audio player app I’m using. By adding the M4, I can also create my own mix by adjusting the volume of the speakers and subs independently, which is pretty cool.
I think the issue may be the setup here.
From what your saying I imagine your going RCA from miniDSP to input TRS on M4.
In general M4 is anticipating pro line level signals in input 3 & 4 and so leaves a significant headroom (something like -16db or -18db (I am going by memory/industry standards, so you may need to check for exact specs).
In contrast the RCA out from your miniDSP should operate at consumer levels which are significantly below pro line level in addition to it only outputing 0.9vrms which is below the standard 2v for unbalanced and 4v for balanced. I imagine you are probably counteracting this on input 1&2 by adding gain through the mic-pre. Equally on the M4, combi inputs 1&2 have different set levels to line level inputs 3&4 so you may also need to account for this when doing your output calculations.
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Thank you for your response.
Yes, I’m going LINE IN 3 & 4 and then out through MONITOR 1 & 2. No pre amp though. I decided to get a Drop THX AAA One as preamp, and see how that resolves.
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I got the THX AAA ONE, and it made little to no difference. Running it on highest gain, and VOL dial at 3 o’clock, M4 VOL dial about the same, and SUB LINE at 12 o’clock. I wonder if I should run the SUBs on normal, and not LFE, since I’m not doing any HIGH/LOW PASS filtering on the DSP end of things.
Well the recommenced way is direct connection to subwoofers and AMP/AMPS without another device.
Something like a passive volume control for subs or amps would be way simpler solution.
Unless changing subs with volume management or something else than MiniDSP to do what it does.