Dynamic Range-Mixer to Camera

filmelife

filmelife

Well-known member
Alright, its obvious that an external mixer with better preamps is good to use along with the camera such as an HVX200.

Now, if the mixer say is 114DB and the camera is 90DB, we are not really gaining any range from using the mixer but basically just getting a quieter operation.

Another words, the mixer is not adding any range at all but basically expanding the range that can be recorded and then compressing it to the camera's audio range?
 
NO.
Mixer has better mic preamps, quality wise.
Bypassing mic pre on camera and using line level is better than camera mic pre.
Metering on external mixer is better and easier to monitor. You can't see audio level on camera while operating camera, or standing next to someone who is operating camera.
Limiter on external mixer far better. If you can get 50-60db dynamic range over backround noise, you are doing good.
There is no shortcut to good audio.
 
Last edited:
nice answer. So using a line level in obviously bypasses internal pre-amps.
so basically, we are using the full dynamic range of the mixer right?
 
How are these specs?

How are these specs?

I don't have an SD or other portable mixer, but I don't require portability. I do have , though, an Alesis Multimix Firewire 8 (also has analog outs). The preamp specs are :


Mic inputs: -60dBu to-10dBu nominal,+5dBu max
Mic gain +10 to +60dB

I plan on using this mixer anytime I need to mix 2 or 3 mics into a channel .
Will I gain anything by using it all the time, rather than recording straight
into the camera mic inputs? (HVX)
 
what i do know is that generally most camera preamps are not the best to use.
For sure you'll get better sound if the mixer has better preamps. The best way to find out is to listen and see whats better, straight into camera, then mixer into camera.
 
Hey, Killa,

The mic preamps on the HVX/DVX are noisy, compared to even halfway-decent external equipment.

The analog circuitry of the HVX/DVX, even when bypassing the preamps, is noisier than even fairly crappy external recorders.

You get a little more USEFUL dynamic range by using external preamps, since the noise floor will be somewhat lower. You'll get more USEFUL dynamic range using an external recorder, because the noise floor will be somewhat lower.

You've got lots of equipment (at one time or another) - all this will be pretty clear if you do some testing and stop worrying about what specs and numbers say. Take, say, your 702 or MixPre (sorry, not 302 I guess) and feed the same signal to the recorder and camera. Bring both recordings (from camera and recorder) into the computer, crank up the levels if ytou need to and listen to the noise, in quiet parts. On the camera side, you'll start hearing all sorts of humms, buzzes, beeps, static, etc. that are far, far more noticeable than on the dedicated recorder.

Doing that, you'll see what we've been saying - the camera audio can be sorta OK if you get the levels just right; but if you need to bump them up later, the camera recording will quickly fall apart.
 
My tests with XH-A1 showed (I posted them here somewhere) that I could get about 80 dB S/N ratio via mic inputs and 90 with line inputs woth SD302. Both of those figures are GOOD, even the mic input route beats any Nagra hands down.

I wish somebody would measure (analyze) the HVX/DVX audio, instead just echoing "crappy, bad, unsuable". I do not believe they are that bad, at least when using line inputs.
 
Some more thoughts about a alledged bad audio on HDV/DVX/XH-A1 etc. etc.

- Some misinformed amateurs use (even) these cameras with internal mics; bad audio = camera has bad audio

- Some better informed amateurs use external mics, but wrong mics in wrong situations in wrong ways; bad audio = camera has bad audio

- Some well informed amateurs (like me sometimes) use good mics correctly, but as the audio on cam is not easy to controll, no limiters (XH-A1), bad meters, plenty of settings which can be misadjusted, the sound sucks; bad audio = camera has bad audio (exept that I do not blame the cam)

- Using good equipment with proper line signal correctly adjusted, voilá: great audio! Nothing wrong with the cam!

So, please somebody make a carefull test recording sending near clipping (line and mic level) signals to the cam, then silence. Capture and analyze in Audition or similar editor. Takes about 15 minutes. I want to know.
 
Yah, yah! I recorded double system today to a MicroTrack and HVX via SD302... I'll try to post some clips tonight or tomorrow.

Petrus - mind you, I'm not saying HVX/DVX audio is bad... I've used it many times when circumstances or budget required - I've made picky musicians CDs from recordings with external mics/preamps that they've been happy with. But, it's easy to do better. Almost anything will do better.
 
You must log in or register to reply here.
Back
Top