View Full Version : Shotgun Microphone Hiss - XLR on xh-a1


Alex Plank
May 27th, 2008, 07:45 AM
I'm using the AT897 (it's a $250 shotgun mic that supports phantom power or battery).

I can hear hiss when when I crank the audio level up. Obviously it's not as noticeable if the mic is closer to the subject and the audio level is set to a lower level.

I'm not sure if this is the normal performance of the camera when it exceeds the noise floor. I assume the mic itself is not to blame (the hiss exists even with nothing plugged in) and I know the cabling is not causing any problems since I'm using high end mogami cables with top of the line connectors. The XLR gain is set to off (up +12db creates more noise as expected). Both phantom and battery power give similar results.

Is this just the result of the XH-A1 not being able to amp the signal straight from the mic to high levels without introducing noise? Would I be able to get rid of this hiss and record audio at higher levels if I ran the mic through a pre-amp and switched my xh-a1 input to take line in?

I'm not looking to fix the hiss in post (which I've had to do so far). I'm also not looking for an inexpensive hack that only slightly fixes the problem. I want to do things right at the time of production and am willing to do what it takes to get professional results.

Doug Lange
May 28th, 2008, 02:06 AM
Did you remove the battery when testing with phantom power? Try a different condenser mic that is known for low self noise. Record the test footage and playback in NLE. Don't rely on the headphone amp on the XH A1. It is noisy compared to what is actually recorded onto tape.

If the footage is still too noisy, get a digital recorder/mixer such as from Sound Devices. However, you will also need a better mic because the AT won't cut it with this recorder.

Petri Kaipiainen
May 28th, 2008, 03:03 AM
If you are not talking about the hiss on tape as analysed with an audio editor your comments are not worth much (I do not mean to be rude, just a fact). Listening with headphones from the camera is not the same thing as the actual audio recorded on tape what comes to hiss levels.

I made some tests with XH-A1 and an extremely low noise microphone and got over 90 dB S/N ratio with SD302 mixer and line in, about 80 dB with mic straight to the camera. This is much better than any $10000 professional analog Nagra system was capable of just a decade ago, so XH-A1 is just super what comes to audio quality. Should be enough for everything.

Ryan Postel
May 28th, 2008, 09:32 AM
I'll keep it a bit lighter... You're not the only one that plugged in some good headphones and became worried from all that his without even plugging in a mic yet!

I had experienced the same hiss when I got my camera, and initially I was worried, but also did audio tests and with some help from people on here, found that the audio was actually really good. There might always be a very small audible noise floor, but its pretty easy to remove or disguise, depending on the circumstance.

Also, for your situation, settings will vary so test whether the attenuator is needed or needs to be turned off. That could help in some instances. A mixer would be nice but not entirely necessary.

Don Palomaki
May 31st, 2008, 07:25 PM
Alex: The A1 has very good audio performance for a camcorder, and objectionable hiss is usually a combination of the audio components being used outside their optimal range. And as noted, headphones will make any hiss much more apparent due to their tight cupling to the ears.

The camcorder mic preamps have a certain noise floor, it is low, but can be amplified to the point of being intrusive.

Similarly condensor mics have a fixed noise floor, and that can be amplifed to the point of being intrusive, most likely happen if the mic is too far from the sound source or if the sound source is a relatively low level.