# NMD - Mackie ProFX8



## Greg Ellis (Oct 1, 2007)

I just bought my first serious mixer this past weekend.

I do mostly acoustic guitars and vocals, performing live on a Shoutcast stream and also some basic recording, jamming along with tracks, learning songs from mp3 or YouTube, that sort of thing.

I did a fair bit of research, and ended up with a Mackie ProFX8 as a good fit for my immediate needs, with some flexibility for later.

http://www.mackie.com/products/profx8/

My prior computer rig used a Line 6 UX1, which gave me two channels to play with - a mic channel and an instrument channel. I fed my vocal mic into the mic channel of the UX1, and mixed all of my guitar sources into the instrument input using a simple 4 channel line mixer (from Wounded Paw). Various soundhole pickups, onboard preamps and even a secondary mic (pointed at the guitar in my hands) all got blended that way, to feed the instrument input on the Line6. I had to preamp the guitar mic to get it up to a usable level, and I used a $50 Behringer MIC100 tube preamp for that.

The Line6 rig was nice for its ability to run two separate simulations to process the two channels. On the guitar side, I could emulate an amp, various effects, different speaker cabs and even mic placement on the virtual cab. On the vocal side, they offered a variety of virtual preamps and effects.

With the Mackie, I'm moving to a much less synthetic sound. There are some onboard effects - various reverbs, slapbacks, delays in the 250-480ms range - but certainly no amp or speaker sims, or anything of that sort.

What I noticed immediately is the noise floor. The Line6 was rather noisy, with a healthy dose of hiss. The Mackie is extraordinarily quiet by comparison. And the ability to pan and blend whatever combination of guitar inputs I might like is very welcome. I'm also noticing that I enjoy changing the virtual sound stage (changing the reverb, for instance) for different songs - that's something I've never done before. It's very convenient with the rotary effects selector on the Mackie. Footswitching the effects off for the times when I'm babbling between songs is also very nice.

The built-in USB interface is working very well for me - I can take inputs from the computer and mix them in my headphones with my live signals. Mackie has a "USB Thru" toggle that lets me choose whether I would like to pass those inputs from the computer back to the computer along with the main mix (if I want to let my audience hear a backing track, for example, or another musician's Shoutcast stream that I'm playing along with). That feature was rather rare when I was researching.

I've yet to hit any sort of serious limitation of the mixer yet, except perhaps I should have got the 12 channel instead of the 8, lol. I guess you can never have enough channels.

I'm very happy with the purchase so far, and the quality of sound it delivers. I'll do my first internet gig with it on Wednesday night; looking forward to that.

The only downside (and really it's not) is that everything is SO clear now, I hear every little flub and fretting accident, every little crack in my voice, etc. It reminds me of the day I brought home my first tube amp.


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## Greg Ellis (Oct 1, 2007)

I'm starting to hit some limits now.

The mic preamps only have about 50db of gain in them. That's enough for the mic I point at my acoustic guitar, but I wish I had maybe 10db more for my vocal mic. I might have to run with an external preamp on that channel.

EQ doesn't offer sweepable mids on this model. That really hasn't been an issue yet, but I can imagine it would be handy to have.

And the rotary control that selects from the 15 or so available reverb effects doesn't have a 1:1 ratio between clickstops and presets. It's a sort of random thing where sometimes one click moves the preset by one, and sometimes it doesn't. It's a minor quibble, I guess, but it would be nice for live situations to be able to change the reverb presets without looking at the numeric display to make sure I've got the one I wanted.

It would be even nicer to switch presets with a foot control, but that would need a midi interface and there's no such thing on this mixer. Maybe I'm asking a lot for the price point. No big deal I guess. Toggling the effects on and off with a footswitch is nice.

There's a lot of chatter on the internet about how noisy the USB interface is on this mixer family. I've noticed it, but it seems to be restricted to one direction - computer to mixer, and it's only distracting to me if the volume on that signal is WAY higher than the other sources, so not a huge deal. The more important direction, from mixer to computer, seems pretty clean to me; so far, anyway.

Trial by fire tonight, I guess, when I use it to stream live to Shoutcast.


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## Greg Ellis (Oct 1, 2007)

I definitely had some issues with the USB link to the computer last night.

Mackie doesn't offer any way to control the level of the signal leaving the mixer via USB. The manual says it's the main mix, BEFORE the mains fader, and ignoring the mains EQ.

Problem for me is that the level is REALLY high, and there's no way to control it as it leaves the mixer. With the mixer setup so each channel input gain barely ticks the peak/clip indicators and with all the channel faders set close to unity gain, I get a lovely mix in my headphones, but I'm overdriving either the ADC that feeds the USB out or else overdriving the mp3 encoder running on my PC. Not sure exactly where that issue is yet, but it sounds awful, obviously.

I had to compensate by reducing all the channel faders. Ugh.

I see a similar issue on the signal coming into the mixer from the computer via USB, but at least there Mackie gives me a knob to twist. I have to run that control quite low to get it near the volume of other inputs; maybe halfway between off and the "unity" detent.

I'll run some more experiments soon, to see if I can fix the USB output level on the computer end, attenuating the level heading into the mp3 encoder. I recently switched to a simple tool called "butt" for that step, but I might need to go back to the Reaper DAW with the Shoutcast plug-in to get more control over levels there.

One last thought - it would be handy to be able to toggle the headphone out so it monitors the Aux busses (monitor mix and fx mix) instead of just the mains. I'm sure I could rig something up external to the mixer, but it would be nice to have that option.


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## Greg Ellis (Oct 1, 2007)

Problem solved, phew! Reaper likes the levels coming from the mixer just fine, and there's a Shoutcast plugin for Reaper that lets me stream the live mix to the interwebs, so all is good again. Not sure what the problem was with BUTT ("broadcast using this tool"), but I no longer care.

Next step is to transfer all my computer-side stuff over to a new desktop PC I just built. It's intentionally low powered, simple, and hopefully quiet.

With the old rig, there was enough hiss from the preamps and such that I didn't really notice the noise of my PC leaking into the mics. Now that my noise floor is a LOT lower (thanks to the Mackie) the predominant background noise in my mix is the whir of my computer fans - on the power supply, CPU and graphics card of my PC.

Hopefully that will all clean up nicely with the new PC.


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