Some audio questions for FX1 at DVinfo.net

Bram Corstjens · January 17th, 2007, 01:04 PM

Hello,

I'm looking for a microphone for my FX1. The thing is however that I really don't like turning up the volume knob above 40 / 50% on the cam because it adds quite some noise.

I figured I have two options to 'fight the noise'

1)
Buy a ME66 because I read that this Sennheiser has a high output power (compared to the AT897 for example). The problem is I don't want to overload the camcorders audio input either. And by that I mean the point where turning down the volume won't help anymore.

Any advise on this? Will the ME66 easily overload the FX1? (p.s I know the ME66 has XLR and the FX1 has minijack, but I can make XLR to minijack convertors. Done it in the past, worked nicely)

2)
What I also can do is buy a Beachtek DXA-8, connect any mic I like and put LINE level audio into my FX1. Will this give me cleaner audio compared to mic level audio?

Thnx!

Hubert Duijzer · January 17th, 2007, 01:16 PM

Hello Bram,

1 You can also consider an Rode NTG-2, it is also a great microphone for a very decent price.

2 The Beachtek DXA-8 is mic level instead of line level, but it has preamps, so with a hot mic like the NTG2 or ME66 you can turn the volume on your camera down.

I have a VX2100 with DXA8 and a NTG-2, and the in camera volume is set on 25-40%, most of the time around 30%. I guess it will work the same with an FX.
Beachtek also makes a model specially for the FX.

Bram Corstjens · January 17th, 2007, 01:40 PM

Quote:

Originally Posted by Hubert Duijzer

Hello Bram,

1 You can also consider an Rode NTG-2, it is also a great microphone for a very decent price.

2 The Beachtek DXA-8 is mic level instead of line level, but it has preamps, so with a hot mic like the NTG2 or ME66 you can turn the volume on your camera down.

I have a VX2100 with DXA8 and a NTG-2, and the in camera volume is set on 25-40%, most of the time around 30%. I guess it will work the same with an FX.
Beachtek also makes a model specially for the FX.

Hi Hubert,

That would be the DXA-6 then which has line / mic switch :)

By the way, I already noticed when I set the FX1 to LINE mode that I almost didn't hear any noise although the volume was set to max.

Just to be sure, I hooked my cam up to the headphones-out of my surround set, played an MP3 and turned up the volume on the surroundset so the meters on the FX1 were in 'the normal' (the volume on the FX1 was till on max)

When I played the captured videofile back on my PC, there was really almost no noise. Even when the music stopped I really had to turn up the volume on my PC to hear any noise at all.

So I guess I can answer my own question: Using the line input gives MUCH better results compared to MIC input. Ofourse one would need decent microphone amplifiers.

Steve House · January 17th, 2007, 01:54 PM

Quote:

Originally Posted by Bram Corstjens

...
Buy a ME66 because I read that this Sennheiser has a high output power (compared to the AT897 for example). The problem is I don't want to overload the camcorders audio input either. And by that I mean the point where turning down the volume won't help anymore.

...!

Not to say the ME66 will overload, but something to watch out for generally, any signal that is too hot can overload and clip at the camera's audio inputs BEFORE the audio gain controls can have any effect. Those controls are actually well into the internal audio chain, after the preamps and such, and overloading CAN occur right at the very start of the chain. In fact, one can have the meters sitting perfectly right where they're supposed to be and still be severely overloading. You need to be prepared with pads to insert into the signal right where it enters the camera should it be necessary to tame it down to the right level.

Chris Barcellos · January 17th, 2007, 02:28 PM

I use the ME66 with FX1. I run it through my Beachtech DX4a. I recently did the DVC Challenge, using the combination.

You can hear what the audio sounded like by checking it out at:

www.makeyourfilm.net

Navigate to the DVC7 challenge, and download one of the version.

I am not a sound man, just kind of set things at what I thought sounded good. Recording was directly to the camera recorded in HDV.

Guy Cochran · January 17th, 2007, 03:24 PM

I would get a DXA-10. Even though it does not screw into the bottom of the FX1 (it has a belt clip). The 10 has line level out and based on our tests here, it's a lot cleaner souding on the FX1. Check eBay
The 10 costs a lot less than an 8 (which is discontinued)

Bram Corstjens · January 18th, 2007, 08:31 AM

Thnx for the advice guys!

I'm currently looking into home-made mic amplifiers. There's this Velleman kit (which you have to assemble yourself) that can be purchased for about 15 euro's. It amplifies mic level to line level. (boosts 40db max)

However, its max output isn't very high. What basically happens is that I have to set the camera's volume to max to get decent levels. As a result, wether I use a microphone directly on the mic input of the FX1 or use a 'standard' 40db amplifier on the LINE input of the cam, I end up with exactly the same amount of noise.

I suppose the DXA-10 has a higher output (since at least one user here reports improved audio) The problem is it's a bit pricey (multiple hundred euros) and its not mountable on cam...

If I find a way to make a microphone amp that amplifies the signal more than 40db, I'm happy and the costs are a fraction of a DXA-10.

For those who are interested (warning, dutch site, but drawings should be understandable anyway)

A transistor based amp
http://www.circuitsonline.net/circuits/view/9

Or this op-amp based one
http://www.circuitsonline.net/circuits/view/58

The problem is they are not documented, so I don't know how to change them so they output the level I want... Anyone knows?

Steve House · January 18th, 2007, 10:26 AM

Bram:

There's an English adage that says "You get what you pay for" or in another variation, "TANSTAAFL - There Ain't No Such Thing As A Free Lunch." Unless you are very good at electronic circuit construction and shielding techniques, it's doubful a DIY preamp is going to be any better than what you already are doing.

To do the job properly you really need to have a either a field mixer or mic preamp with meters and that can supply 'tone,' a reference signal for calibration. The idea is that when your preamp or mixer is putting out a steady tone at reference level, you put the camera on manual and adjust the input controls so that the camera's meters read -12dBFS and don't move them away from that setting. That should occur with the camera level controls about mid-range. If it's too hot, add an inline pad to drop it down. Your mic plugs into the mixer or preamp and you use the mixer level controls so that the signal registers between 0 and +4 dB on the mixer's meters as you shoot.

January 17th, 2007, 01:04 PM	#1
Bram Corstjens Regular Crew Join Date: Mar 2003 Location: Netherlands Posts: 126	Some audio questions for FX1 Hello, I'm looking for a microphone for my FX1. The thing is however that I really don't like turning up the volume knob above 40 / 50% on the cam because it adds quite some noise. I figured I have two options to 'fight the noise' 1) Buy a ME66 because I read that this Sennheiser has a high output power (compared to the AT897 for example). The problem is I don't want to overload the camcorders audio input either. And by that I mean the point where turning down the volume won't help anymore. Any advise on this? Will the ME66 easily overload the FX1? (p.s I know the ME66 has XLR and the FX1 has minijack, but I can make XLR to minijack convertors. Done it in the past, worked nicely) 2) What I also can do is buy a Beachtek DXA-8, connect any mic I like and put LINE level audio into my FX1. Will this give me cleaner audio compared to mic level audio? Thnx!

January 17th, 2007, 02:28 PM	#5
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	I use the ME66 with FX1. I run it through my Beachtech DX4a. I recently did the DVC Challenge, using the combination. You can hear what the audio sounded like by checking it out at: www.makeyourfilm.net Navigate to the DVC7 challenge, and download one of the version. I am not a sound man, just kind of set things at what I thought sounded good. Recording was directly to the camera recorded in HDV. __________________ Chris J. Barcellos

January 17th, 2007, 03:24 PM	#6
Guy Cochran DVCreators.Net Join Date: Oct 2001 Location: Seattle, WA Posts: 892	I would get a DXA-10. Even though it does not screw into the bottom of the FX1 (it has a belt clip). The 10 has line level out and based on our tests here, it's a lot cleaner souding on the FX1. Check eBay The 10 costs a lot less than an 8 (which is discontinued) __________________ Guy Cochran DVinfo Sponsor, Cool Gear - DVeStore!

January 18th, 2007, 10:26 AM	#8
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	Bram: There's an English adage that says "You get what you pay for" or in another variation, "TANSTAAFL - There Ain't No Such Thing As A Free Lunch." Unless you are very good at electronic circuit construction and shielding techniques, it's doubful a DIY preamp is going to be any better than what you already are doing. To do the job properly you really need to have a either a field mixer or mic preamp with meters and that can supply 'tone,' a reference signal for calibration. The idea is that when your preamp or mixer is putting out a steady tone at reference level, you put the camera on manual and adjust the input controls so that the camera's meters read -12dBFS and don't move them away from that setting. That should occur with the camera level controls about mid-range. If it's too hot, add an inline pad to drop it down. Your mic plugs into the mixer or preamp and you use the mixer level controls so that the signal registers between 0 and +4 dB on the mixer's meters as you shoot. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

January 17th, 2007, 01:16 PM	#2
Hubert Duijzer Regular Crew Join Date: Oct 2006 Location: Netherlands Posts: 177	Hello Bram, 1 You can also consider an Rode NTG-2, it is also a great microphone for a very decent price. 2 The Beachtek DXA-8 is mic level instead of line level, but it has preamps, so with a hot mic like the NTG2 or ME66 you can turn the volume on your camera down. I have a VX2100 with DXA8 and a NTG-2, and the in camera volume is set on 25-40%, most of the time around 30%. I guess it will work the same with an FX. Beachtek also makes a model specially for the FX.

January 18th, 2007, 08:31 AM	#7
Bram Corstjens Regular Crew Join Date: Mar 2003 Location: Netherlands Posts: 126	Thnx for the advice guys! I'm currently looking into home-made mic amplifiers. There's this Velleman kit (which you have to assemble yourself) that can be purchased for about 15 euro's. It amplifies mic level to line level. (boosts 40db max) However, its max output isn't very high. What basically happens is that I have to set the camera's volume to max to get decent levels. As a result, wether I use a microphone directly on the mic input of the FX1 or use a 'standard' 40db amplifier on the LINE input of the cam, I end up with exactly the same amount of noise. I suppose the DXA-10 has a higher output (since at least one user here reports improved audio) The problem is it's a bit pricey (multiple hundred euros) and its not mountable on cam... If I find a way to make a microphone amp that amplifies the signal more than 40db, I'm happy and the costs are a fraction of a DXA-10. For those who are interested (warning, dutch site, but drawings should be understandable anyway) A transistor based amp http://www.circuitsonline.net/circuits/view/9 Or this op-amp based one http://www.circuitsonline.net/circuits/view/58 The problem is they are not documented, so I don't know how to change them so they output the level I want... Anyone knows?