portable sound recording question

[ericMartinJarvies]

i am just now starting to delve into my sound recording equipment(actually trying to use it), and have some questions:

i am using a sennheiser 816 shotgun mic and a tascam da-p1 portable dat. the 816 plugs into a little sennheiser mza 16 p48 box, and an xlr goes from the box to the tascam da-p1.

am i missing anything? the system works/records sound just fine, but i have been reading about production mixers/portable mixers, and it seems they are used in general ... but i do not know the benefits of using a mixer beyond being able to plug in more then one mic. is that their sole purpose, or is there more to it?

also, the little sennheiser mza 16 p48 box that the mic plugs into has the following controls:
dB Hz
0 20
-10 140
-20 80

what would warrant using the above mentioned settings? in other words, what is technically recognized to make one decide to switch between -10dB and -2odB for example? or using 140Hz instead of 20Hz?

sounddevices.com has a portable unit called the 302, and one called the MixPre. anyone familier?

a general overview/explaination would be apreciated.

eric

[al77]

I havent used this mixer but the 0/10/20dB button is probably a 'pad' button used to adjust the sensitivity of the mic. You'd adjust it according to how sensitive you need the mic to be - using 0dB to record quiet sounds & the 10/20dB pad to record louder sounds. It's a matter of monitring the source to match the sensitivity. Of course you want the mic to be sensitive enough to pick up the sound but not so much as to introduce distortion.

The other control - it could be a bass roll off control / hi-pass filter (gets rid of all frequencies below the cutoff point 20/80/140Hz) probably used to reduce low frequency background noise such as traffic or wind - have you got a picture or a link?

cheers,

[danpuddick]

The reason you might have a production mixer is 1) so you could use several mikes and 2) because the mic pre amps on it might be of a higher standard than those you have.

You also might want to use a field mixer to boost or reduce certain frequncies which are undesirable to you..

If your recording sounds good as it is I would stick with that.

As for the -10dB and -20dB marking on the Unit I guess these are different output levels with the -10dB being the higher level.

The frequency markings look to me like high pass filters to cut off low frequencies (rumble which can make your recording sound bad (sort of muddied)... These are sometimes called LO CUT...that's a guess but mixers have a similar switch so it seems likely. I think you'd have to do a test here, by ear to see how it sounds.....

The MZA 16 p48 is the power supply for the microphone, which works on 'phantom power'. This means that microphone is powered from the mixer, pre amp or recorder it is plugged into via the shield on the cable..... but sometimes the mixer, pre amp or recorder is not equipped for phantom power so you need something like the MZA 16 p48 to put in between your mic and your mixer/recorder...... however, your DAT does in fact have a switch for Phantom power on it's XLR input so perhaps you don't need the MZA 16 p48 box. (I just worked out the p48 must stand for Phantom +48v!) Have a look in the manual for the DAT and it should explain a bit about Phantom Power or give google a bashing!

good luck


DANIEL

[danpuddick]

sorry al you posted why I was writing :oops:

[ericMartinJarvies]

I havent used this mixer but the 0/10/20dB button is probably a 'pad' button used to adjust the sensitivity of the mic. You'd adjust it according to how sensitive you need the mic to be - using 0dB to record quiet sounds & the 10/20dB pad to record louder sounds. It's a matter of monitring the source to match the sensitivity. Of course you want the mic to be sensitive enough to pick up the sound but not so much as to introduce distortion.
Not sure about the other control - it could be a bass roll off control / hi-pass filter (gets rid of all frequencies below the cutoff point 20/80/140Hz) probably used to reduce low frequency background noise such as traffic or wind - have you got a picture or a link?
cheers,

ok. makes a little more sense to me. so the benefit of a mixer like the 302 or mackie?

when filming scenes on an average film production, is it typical to use only one mic? or is it typical to use multiple mics ... for example, if there is dialoge between two people, would it be best to move one microphone between the two(point it towards each as they talk) people? or would it be best to have a microphone for each?

also, regarding two subjects that have a considerable distance between them ... how is it best ot record them? i am just trying to get a good sense/understanding of when to use what and why.

eric

[pvanscherpe]

Hello,
Mixers are are also used due to the superior preamps they have. The Sennheiser mics tend to run hot and you might get distortion very easily. If while recording your input levels are set to below 3 watch out. The meters are after the preamps and a/d conversion so your meters might look great but your are distorting the front end. I have a Sony TCD-D10 Pro that used to distort when recording sharp noised such as a small drum. The levels would look great but I would have distortion. I have gone to using a Apogee Mini-Me as a preamp and then run the digital signal into my DAT using the AES/EBU inputs. Your Tascam might have S/PDIF inputs. Another solutions would be to use the pads that you mentioned. I use a 20db pad when I use my Nagra reel-to-reel with my Senheiser mics.

[ericMartinJarvies]

Hello,
Mixers are are also used due to the superior preamps they have. The Sennheiser mics tend to run hot and you might get distortion very easily. If while recording your input levels are set to below 3 watch out. The meters are after the preamps and a/d conversion so your meters might look great but your are distorting the front end. I have a Sony TCD-D10 Pro that used to distort when recording sharp noised such as a small drum. The levels would look great but I would have distortion. I have gone to using a Apogee Mini-Me as a preamp and then run the digital signal into my DAT using the AES/EBU inputs. Your Tascam might have S/PDIF inputs. Another solutions would be to use the pads that you mentioned. I use a 20db pad when I use my Nagra reel-to-reel with my Senheiser mics.

yes, my tascam has s/pdif. so what are you saying? the mixer turns the signal from the mic into a digital signal that is then sent to the tascam for recording to dat?

[pvanscherpe]

Yes some of the mixers like the Apogee Mini-Me and Gracedesign's Lunatec V3 have built in A/D converters. They also have limiters and compressors. Using something like this will completely bypass the poor preamps and the A/D converters and metering of the DAT recorder.

I would say that this would be the best way to go. But it is not the only way. Comming down the ladder would be just usinging a Preamp with not a/d conversion. Next would be using a pad to reduce the mic level.

There is also nothing wrong with recording analgue and then digitizing it.

[al77]

I'd do some tests with your current gear & see what sort of results you get before spending more money on a mixer. I've used a da-p1 dat a lot & had great results (though admittedly this wasn't for film sound) you might be surprised at just how good the sound is.

[pvanscherpe]

I fully support the idea of a sound test. Take your recording gear into a room and record yourself. Get loud and adjust the levels. If you have actors that get mad or loud get as loud as you think they will, then play back your recording and use a good set of headphone like a pair of Sony MDR 7506 to hear what you recorded.

This is something that I did not do before the first film that I recorded the sound for and every tap of the small hand held drum distorted.

[danpuddick]

Eric

I did a quick google search and found this web site http://www.equipmentemporium.com/articles.htm

It has loads of articles on recording sound for film...

hope they are of some help..

daniel

[ericMartinJarvies]

thanks everyone. it is nice to know i cna plug directly into the dat instead of using that extra piece of hardware. the portable sound portion of my film's pre production educational experience is one i will delve into in the weeks to come. i will no doubt conduct tests as many of you have suggested. i have found testing is the only real way to truly get to know your equipment. however, when one does not have certian pieces of equipment, then one cannot know what he is missing out on, or not benefiting from, hence the mixer question, multi-mic question, etc.

i have decided to purchase a mixer and another mic(but a short shotgun for interiors) ... but what i have not bee nable to decide or determine is if i at any time should be filming/rolling sound using two mics at the same time. could osmeone explain why one would use two mic's at the same time while filming a scene?

thanks,

eric

[pvanscherpe]

Hi Eric,
Before moving on to multiple mics do you have a boom pole (12 feet or better is a good length), shock mount and wind sock? If you are indoors you can probably get along without a windsock. You will see very soon or perhaps you already know that a dual sound system requires a crew.

I have nevered recored more than one track at a time. But, it is not too hard to imagine a need for more. If you are recording a band you certainly will need several mics and a mixer. There are several good website that you might want to check into and read the posts. My favorite is amps.net it is the association of motion picture sound in the UK and they have been extremely helpful to me. You might want to consider finding someone who will record the sound for you and has the equipment already. Location sound recording is its own specialty as is post production sound.

If you were in the bay area I would offer to do it for you or you could post a request at filmarts.org but I would really recommend that you find a local volunteer to do the recording for you so you could concentrate on the picture.

[discs of tron]

i often mix signals when i'm doing concert type stuff. also, sometimes there are situations where you're using, say, two lavs and you want them on separate channels for post. also, for doc type stuff, it can be cool to have a boom going to one channel and a camera mic to another as a backup.

[Pedro]

From time to time I have to record speaker with background music and the result should be rather professional, as it is used as a playback CD in live theatre shows.

I found out that I can get the most vivid voice, recording it with a directional mike and at the same time with a omni-directional stereo mike.

I record to 3 tracks of the TEAC A-3440 tape machine at highest speed when no background music is required or to two tracks when background music should be added.

The analog recording is less sensitive to too high levels, when the speaker resolves to shout too loud, and the listener has subjectively more "live feeling" as when recorded totally digitally.

Then I mix all tracks with an analog mixer (tascam) and transfer it to aiff for the CD. The result is crystal clear, without any hiss or hum and with a very vivid and dynamic sound, good enough to use in the theatre at high volumes.

For mobile recording, I use the Sony WM-D6C walkman which also record free from hiss (Dolby C) and with a impressive dynamic range. As it is dificult to control several microfones in outdoor situation, I decide upon the situation, if a stereo mike could be better or a directional one.

Pedro