You are here

How to build a three-mic passive combiner?

Customising, building or repairing your own gear? Need help with acoustic treatment or soundproofing? Ask away…

Moderator: Moderators

Re: How to build a three-mic passive combiner?

Postby DC-Choppah » Sun Mar 07, 2021 11:08 pm

Sam Spoons wrote:Why not just buy an interface with 16 mic/line inputs and dispense with the mixer? Simplifies the system and removes two old pieces of kit?

The mixer lets us set up monitor mixes for recording multiple musicians at the same time and setting reconfigurable groups to the interface, all without moving any wires around.

We monitor everything in the analog domain before it goes to the DAW. Zero latency.

I currently have 29 things that can come into the mixer and don't have to change any wires to get access to them. We have mic switch boxes that can switch in all 8 of the drum mics in at once, or switch in another group of 8 mics, etc.

The mixer lets me set up monitor mixes and I can see what is going on instantly and record and monitor any combination.

When I get a bunch of people in there trying to make music at the same time, I don't like to be messing with the mouse and moving wires around.

To do that with the interface I would need another dedicated screen to see the interface mixer, and would have to plug and unplug wires. To me that is when the confusion starts.
User avatar
DC-Choppah
Frequent Poster
Posts: 1747
Joined: Fri Jul 20, 2012 12:00 am
Location: MD, USA

Re: How to build a three-mic passive combiner?

Postby The Elf » Sun Mar 07, 2021 11:28 pm

This is why I like RME interfaces for TotalMix. It takes care of all these things effortlessly. I can even set up personalised monitoring for each band member from an iPad in the studio where I can be alongside them and make sure they're happy, away from the recording computer.
User avatar
The Elf
Jedi Poster
Posts: 16579
Joined: Tue Aug 14, 2001 12:00 am
Location: Sheffield, UK
An Eagle for an Emperor, A Kestrel for a Knave.

Re: How to build a three-mic passive combiner?

Postby Sam Spoons » Mon Mar 08, 2021 12:16 am

DC-Choppah wrote:
Sam Spoons wrote:Why not just buy an interface with 16 mic/line inputs and dispense with the mixer? Simplifies the system and removes two old pieces of kit?

The mixer lets us set up monitor mixes for recording multiple musicians at the same time and setting reconfigurable groups to the interface, all without moving any wires around.

We monitor everything in the analog domain before it goes to the DAW. Zero latency.

I currently have 29 things that can come into the mixer and don't have to change any wires to get access to them. We have mic switch boxes that can switch in all 8 of the drum mics in at once, or switch in another group of 8 mics, etc.

The mixer lets me set up monitor mixes and I can see what is going on instantly and record and monitor any combination.

When I get a bunch of people in there trying to make music at the same time, I don't like to be messing with the mouse and moving wires around.

To do that with the interface I would need another dedicated screen to see the interface mixer, and would have to plug and unplug wires. To me that is when the confusion starts.

:thumbup: :thumbup:
User avatar
Sam Spoons
Jedi Poster
Posts: 15643
Joined: Thu Jan 23, 2003 1:00 am
Location: Manchester UK
Still taking this recording lark seriously (and trying to record my Gypsy Jazz CD)........

Re: How to build a three-mic passive combiner?

Postby blinddrew » Mon Mar 08, 2021 12:31 am

A Tascam US16x08 would give you 8 mic pres, 6 line ins, 2 instrument ins (that can handle line level), midi and USB. Everything from your list bar reverb I think.
User avatar
blinddrew
Jedi Poster
Posts: 14253
Joined: Sun Jul 05, 2015 12:00 am
Location: York
Ignore the post count, I have no idea what I'm doing...

Re: How to build a three-mic passive combiner?

Postby James Perrett » Mon Mar 08, 2021 12:53 am

Sounds a bit like the ubiquitous X32 could be used here - all the inputs could then be left permanently connected. Otherwise there's my usual recommendation of an RME Digiface USB with whatever combination of A/D convertors you prefer which will give you up to 32 inputs although, like Drew's suggestion, it doesn't give you reverb. You need to go up to one of RME's more expensive interfaces with built-in DSP to get reverb.
User avatar
James Perrett
Moderator
Posts: 10569
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: How to build a three-mic passive combiner?

Postby DC-Choppah » Mon Mar 08, 2021 2:20 am

A second M-Audio Fastrack Ultra 8r seems logical. And I keep the reverb for the monitor mix which I need.

But I am seeing that Avid says that I can't run Protools with two interfaces?!?

Is this a rabbit hole?
User avatar
DC-Choppah
Frequent Poster
Posts: 1747
Joined: Fri Jul 20, 2012 12:00 am
Location: MD, USA

Re: How to build a three-mic passive combiner?

Postby DC-Choppah » Mon Mar 08, 2021 4:18 am

I had not realized that my M-Audio's built in monitor effects was such a special thing. :problem:

The M-Audio software mixer has an EFX send on every channel (8 hardware inputs) that you can add effects to and the effect only shows up at the monitor output and is not burned into the DAW.

So how are folks 'adding a little reverb to the monitor' while tracking these days if the reverb is not built into the interface?
User avatar
DC-Choppah
Frequent Poster
Posts: 1747
Joined: Fri Jul 20, 2012 12:00 am
Location: MD, USA

Re: How to build a three-mic passive combiner?

Postby The Elf » Mon Mar 08, 2021 9:18 am

DC-Choppah wrote:So how are folks 'adding a little reverb to the monitor' while tracking these days if the reverb is not built into the interface?
Well it *is* built into my interface (MADIFace XT), but I rarely use it. I have an old MIDIVerb 4 I can tap into.
User avatar
The Elf
Jedi Poster
Posts: 16579
Joined: Tue Aug 14, 2001 12:00 am
Location: Sheffield, UK
An Eagle for an Emperor, A Kestrel for a Knave.

Re: How to build a three-mic passive combiner?

Postby James Perrett » Mon Mar 08, 2021 3:23 pm

DC-Choppah wrote:But I am seeing that Avid says that I can't run Protools with two interfaces?!?

It depends on how the interfaces are presented to the software. The drivers need to be able to combine the data from the two interfaces and present them as if they were a single interface to the software. Some RME interfaces allow this and I think my old Focusrite would also allow more than one interface to be used. I don't know if this applies to M-Audio or not but, if it does, you need some way of syncing the digital clocks of the two devices together using SPDIF or similar.
User avatar
James Perrett
Moderator
Posts: 10569
Joined: Mon Sep 10, 2001 12:00 am
Location: The wilds of Hampshire
JRP Music - Audio Mastering and Restoration. JRP Music Facebook Page

Re: How to build a three-mic passive combiner?

Postby DC-Choppah » Tue Mar 09, 2021 6:05 pm

I tried a few experiments and could not get a second interface to work with the M-Audio. It is just not set up for that it seems.

OK so if I get the TASCAM US16x08 (thanks Drew) then I will have 16 channels.

So to put a little reverb on the performer's monitor (which we really like), I would need to use one of the monitor outputs on the TASCAM as a send to an external reverb. I have an old nano-verb. Then bring the return back in on one of the input channels. So I lose an input channel. We can record 15 channels at once.

That will work.

I get an 8 mic drum setup, and up to 7 more instruments - bass, keys + to record the rythm section groove simultaneously.
User avatar
DC-Choppah
Frequent Poster
Posts: 1747
Joined: Fri Jul 20, 2012 12:00 am
Location: MD, USA

Re: How to build a three-mic passive combiner?

Postby Hugh Robjohns » Tue Mar 09, 2021 6:16 pm

DC-Choppah wrote:So to put a little reverb on the performer's monitor (which we really like), I would need to use one of the monitor outputs on the TASCAM as a send to an external reverb.

You could use a plug-in reverb effect in the computer -- doesn't need to be an external effect processor -- and that way you won't lose an input channel. There would be some latency in the round trip, obviously, so it wouldn't work for 'comfort compression', say, but for reverb it will just feel like a little pre-delay and won't be noticed.

And you can do it in stereo...
User avatar
Hugh Robjohns
Moderator
Posts: 30718
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound
In my world, things get less strange when I read the manual... 

Re: How to build a three-mic passive combiner?

Postby DC-Choppah » Fri Mar 12, 2021 6:20 am

Hugh Robjohns wrote:You could use a plug-in reverb effect in the computer -- doesn't need to be an external effect processor -- and that way you won't lose an input channel. There would be some latency in the round trip, obviously, so it wouldn't work for 'comfort compression', say, but for reverb it will just feel like a little pre-delay and won't be noticed.

And you can do it in stereo...

Ok. Thanks for that. I played with this configuration in Protools.

To get it to work, I have to
- Take Protools out of 'Low Latency Monitoring' mode, since in Low Latency monitoring mode Protools silences all tracks when record enabled, including the pre-fader sends.

-Put the reverb on a pre-fader send. This way when I mute it, I still get the reverb returned.

-Mute the track when recording it. That way only the reverb return from the track comes back on the software return to the interface.

I tried this on my normal buffer size of 1024 that we always use. We monitor only in the analog domain so that buffer size doesn't matter, so I just set it to max and forget about it.

Even at this buffer size the reverb sounds natural and happy. Fun to play into.


So this is good. The only thing is that now when recording a track, you have to remember to also mute it. That's a bit of funny thing and an extra step.


Protools does not seem to have a natural configuration for this. The low latency monitoring would automatically kill the record track so that we didn't hear it in the monitoring. But since I had to disable that, we now have to mute the track to record it and then unmute it to listen back.
User avatar
DC-Choppah
Frequent Poster
Posts: 1747
Joined: Fri Jul 20, 2012 12:00 am
Location: MD, USA

Previous