Why would you prefer a MixPre over an MM-1 if you're operating a boom

R

raffnix

Member
Hi guys

I was always wondering why everyone is talking about the SD mixpre (665$) instead of MM-1 (385$) or even MP-1 (325$) as a good entry level mixer. The preamps of all devices are the same. And when you operate a boom you only need one channel anyway. Wireless lavs already have their own preamps (before transmission). So why would you need that second channel? Only to be able to operate two wired lavs at the same time? (Or one lav and one boom?). Or is it the level meter of the mixpre? But I can easily set up the gains of my recorder and say an MP-1 so that the meter of my recorder (R-44) matches.
Considering my recent work, one decent channel is all I am asking for.

Cheers,
Raphi
 
Sometimes you want 2 mics. Like a lav and a boom mic on one subject to cover your bases. Or there are 2 people on camera with 2 lavs, or 2 booms. Maybe today you only need one channel, but tomorrow someone wants you to record in stereo. If you are prepared you can take that job and earn more money. Spending an extra 300.00 today will earn you much more than that because you can take the jobs. But there is nothing wrong with using a good one channel premamp if that's all you want. Most pros need more than one channel at least some of the time.
 
Really, the second channel means more flexibility. Especially if you're running a one-person sound setup where you are both boom op and mixer.

The addition of a 1kHz tone generator makes gain staging/signal calibration much more reliable.

Last, the meters are indispensable.
 
Hey Chad

Thanks for your response. I get your point about future investment. However, in my case, I guess the MP-1 is all I need. My R-44 has some 'ok' preamps to handle other mics. So, I would use the MP-1 for booming on channel 1 and other mics plugged to channel 2-4. Lavs are usually quite close to the source so they won't need that much gain, right?! So, preamp quality shouldn't be that critical. And I don't see me working with two booms in the near future.

Cheers,
Raphi
 
raffnix said:
Lavs are usually quite close to the source so they won't need that much gain, right?! So, preamp quality shouldn't be that critical.
Click to expand...

I'm not sure you understand gain.

No matter how close a mic is to the source, how much gain increase it requires is really based on the level of the mic's output. Some have hotter output than others, and it certainly varies from mic to mic. Either way, a mic still has to go through a pre-amp whether it's an MP-1, and MM-1, the MixPre, or straight into the R-44. Pre-amp quality always matters.

If you go through an external pre-amp first, you'll be sending line-level out to the R-44. I would hope that switching to line-level input on the R-44 would bypass the pre-amp, but another recent thread comments that it does not. You do minimize added/amplified noise when you go to line-in so it may or may not cause any problems, but the fact is that you're still going through them. If you are using wireless lav systems, you need to check and make sure that your receivers can output line-level as well.
 
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The R-44 is "line level" when the trim (outer) knob is all the way down. And try not to turn the inner, level knob up past 50%, or 12:00. Beyond that it is only digitally increasing gain.


I just got done with a long rant about how you don't want to change your record levels on the recorder as a means to adjust mic volume. That will change your noisefloor. That bad... The mixer lets you change the mic level without the noise caused by the recorder getting louder. Read the last couple of pages of the "Great Divide" thread for a more complete description of why a mixer is necessary for dialogue.
 
I went with the Sound Devices MM-1 instead of the MixPre because I only use one mic for the time being and it was cheaper. If that changes in the future, I figure I can always resell the MM-1 as it's a sturdy bit of kit that'll hold up well, and then purchase a MixPre. As for meters, I think they are likely more important on the recording device since that's the sound you'll end up with. The MM-1 has an LED to indicate clipping, which is about all I need to be informed of on the pre-amp side. Likewise, it's more valuable to monitor with headphones the sound you're actually recording, but that can be fed into the monitor input on the MM-1 so the MM-1's headphone output can be put to use as well.

So really, as others have suggested, the main difference is number of mic inputs. But I admit the tone generator would be convenient.
 
Thanks everyone for your thoughts about the topic.

C2V, thanks for your input. Although, I think I have a good understanding of what gain is and what's important. Actually, the key issue is not necessarily "output level" but rather signal-to-noise ratio. If you use a super hot mic that generates a lot of thermal noise or third order harmonics you didn't win anything, right? On the other hand, given any mic, it is always of utmost importance to move the mic as close to the source as possible (I am sure you'll agree with me on that one). Again, what you're really trying is to maximize your signal-to-noise ratio (in this case increasing signal level in relation to room noise, reflections...). Now, considering a sufficiently hot lav, the preamp quality is less important than for a shotgun oder hyper with the same hottness. Just because of distance.
However, I don't own a lav and so far have only worked with wireless Sennheisers (which didn't thrill me in terms of quality). If lavs are generally less hot due to size (or whatever reason) and that's what you were trying to say then yes, in that case the preamp is again most critical to the signal chain.

Cheers,
Raphi
 
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