Audible hiss with Sony XLR-K2m audio unit

M

mactas

Member
Hi there,

I've been trying to solve this for ages and it is driving me nuts. I have a Sony XLR-K2M that I plug into the hotshoe of my Sony A7S. Now there is even hiss being outputted from it before I have connected a mic to it. This is evident when monitoring and in recorded playback. I currently have it set to 0db attenuation and set to 'mic'. When it is set to -10db obviously it reduces but then there is a weird digital noise that is apparent that is even worse and you are losing a lot of the frequency range.

This hiss noise also occurs when connecting my Sony UWP-D11 radio mics. I have tried setting the in camera audio levels to 0 before connecting the unit but this does nothing. The sony A7S is known to have pretty good preamps so I'm pretty sure it is the K2m unit as the hiss ins't there when using the A7S internal mic. I have also boosted the gain within the radio mics and this still doesn't help reduce the continuous low hiss from the unit. I am out of options other than sending it to Sony to see if it it is a faulty one. Has anyone out there had any similar problems?

Thanks,
 
Have you tried exercising ALL the audio adjustments throughout their range to confirm that they work and produce the expected results?
No video camcorder of any price (and especially not a DSLR) has "pretty good preamps". Average is as good as it gets.
The best you can hope for is using some nice quiet external gain (from a mixer or mic preamp) and hoping for the best inside the camera.
 
It has pretty good premaps in comparison to other cameras. Yes I have tried all the settings possible. Everything 'works' but contains a hiss.
 
Hiss and white noise are mentioned in a number of reviews of the K2M so it might well be just be what it is. Even the most positive reviews I read don't talk about great preamps. Basically this is a convenience device.

You could send it back and try another but I suspect it will sound the same.

So you either need to use noise reduction in post to get rid of the noise, not a great choice but probably pretty effective since it is a very consistent noise, or return it and get a decent mic preamp. Or better get a recorder.
 
Thanks Scott,

Yeah I'm coming to the realisation that it is just a shoddy unit and not professional enough quality for my needs. I have been cleaning up the sound in post but it's another step that I would like to avoid. I'm now looking at selling it and perhaps buying a Zoom H6 instead.
 
mactas, have you ever asked yourself why do broadcast and 'Pro' level productions spend 20 times or more than what you have spent on gear?
Do you think they have money to burn or they are after something else.... like quality, reliability, usability?
It seems you are after 'Pro' level results on hobbiest level gear budget, the zoom H6 should still be regarded as base level and a long way from 'Pro' level.
 
Err yeah that's helpful. I fully realise that pro gear is far
more expensive and better quality. That doesn't mean that the prosumer gear that Sony sell should record hissy sounding audio. I can't afford pro level gear and I'm here trying to find out how to fix a problem and not get advice about how great pro level gear is. That's pretty obvious isn't it.
 
Exactly what is "pro" gear and what isn't is fairly blurry in the mid range today. Most "prosumer" gear today has better spec's in most areas than very high end pro gear of 20 years ago or so (probably don't have to go that far back...).

mactas, I personally have not had good experience with Zoom and build quality, noisiness, etc. So I would be looking at Tascam. Other than a special cable for the DR-70 if your going to a DSLR (a "bug" that will I'm sure be dealt with in a next version) the reports have been good for the various units they make pretty much for exactly what you are doing. You can mount them to the camera, they have decent preamps, the later models have better gain for low out put mics. You get the plus of being able to record dual system and at the same time feed the camera. If the camera audio works for you then the recorder is a backup, if the camera's audio isn't up to it then you can pretty easily post sync the recorders audio since it is the same signal. And they are affordable.
DR-60, 60 MKII, 70 are all good choices. Handheld recorders are more problematic for doing what you are talking about.

A lot of what you get by spending a LOT more is durability, quality control and support. You also get features in some cases and better/ quieter/ more control/ etc components. But the sound "quality" jump is not huge from decent prosumer gear and top professional gear except in extreme cases. If you are doing some very delicate recordings with really great mics in a very quiet room and need lots of very clean gain, then you will certainly hear the difference. If you are doing indi dialog or production recording in general then your biggest quality issue is your technique. There is so much other "noise" and "junk" in the field that the slight difference in electronics is not going to mater much. Getting mic placement right and such is a MUCH bigger factor.

If your making the big bucks you are going to get things like Sound Devices and Nagra and Lectrosonics, because they specialize in exactly what you are doing so their tools are more focused on what YOU need rather than being a consumer catchall (you don't find guitar tuner functions in their gear...). They have good support that, again , knows your field and is not going to give you some BS answer. And the gear is built to withstand the torture of field recording. You can literally drive a car over a MixPre and not damage it.
 
I wasn't convinced with the Tascam DR 60 as it has digital potentiometers which sound awful if they have that step up sound. Is that still the case with the Dr-70 too? Have you used the H6 then? I know the h4N was pretty bad but this new one does look like a big improvement and I've not seen any bad reviews about it. It also has a dedicated line out which can be attenuated which is pretty useful as you can then dual record quite easily.
 
No haven't used the H6. Not sure what the big deal with stepped level control is since really you shouldn't be messing with it while recording. I know it was a big issue, or people got hung up on it anyway, so maybe it's "fixed". I have a very $$$ high end mic preamp and it's levels are set with rotary switches, one for each channel. I actually preferred that to the MixPre with the way too easy to move level controls. I tried a number of things to make the MixPre controls more like the other but nothing really worked well so I just had to learn to keep things away from the knobs.

The 70 has a dedicated feed for the camera which I believe is also true for the 60's.

Since most people seem to want to use these attached to the camera you can't touch the knobs while shooting with out wiggling the camera anyway so again what is the point?

But I'm not here to sell Tascam equipment, if you want to buy Zoom go for it. My experience hasn't been great. The H2 had a flimsy card door that broke almost instantly, the H4N I used once, a friends, had almost all of the markings worn off after about six months of use. They are a consumer "toy" company working on upping their game so I imagine the later stuff is better than the earlier stuff. Tascam is a professional sound company that has been around a LONG time and started playing around with the consumer market. Certainly going in the later had better support and were more attuned to the needs of film and music pros/ semi pros. But where the balance is right now?

For me the H6 is kind of one of those "but wait there is more..." kinds of devices. Instead of picking something and trying to do it well they decided to do everything. My personal experience is that when folks try to cover too many bases they end up doing none of them particularly well. Also it's a hand held so it's not at all set up to do the task you want it to do.

But a lot of folks get kind of fixed on something and over look issues. I've done it so... It's not going to suck, and who knows for you it might be the best thing since sliced bread. I might even love it, but it's going to take some convincing for me to spend money on a Zoom product again.
 
I have a Zoom H6 and also H4n, the H6 input controls are touchy and would be a pain in the A*&% to ride during a recording. They are more of a set the level and don't touch it......
If you want to 'ride' the levels then you need to put a mixer up front. But these days most of the 'NEW' generation of sound people seem to set it and let it happen then fix the result (or let someone else fix it) in post production.

I have a client that produces 'training' videos often in a lecture theatre style and wants a 'ready to edit then duplicate' style audio as he doesn't want or need to go to audio post production, so I deliver a dual mono, mixed, constant levels, limited with roll off (HPF) to suit the lecture room.... sent to both cameras.
 
Now most of my recordings are for FX, but since I do a lot of post I can maybe shed some light on the two orientations to recording, riding gain VS set and leave alone.

With analog, yes I am that old, you really had to maximize the signal going to tape. You were fighting a built in noise bed on the tape and the limits of the electronics of the day. So riding gain was an important tool to keep a healthy signal going to the tape whatever the sound level was hitting the mic.

Digital has few of the same problems. There is essentially no "tape hiss" or built in noise in the media and the electronics of mid grade gear today are incredible compared to not lang ago.

In post, in the good old days, you were mixing on the fly with everything happening live. We didn't get "flying faders" (level automation) till the 1990's, and that was only levels. Anything that smoothed out the proses was a plus and there was no such thing as file processing like we do today for noise reduction, so levels shifting around were more of a plus that a negative.

Today we do a lot of digital processing on files and things like noise reduction are made MUCH harder if the levels are moving around. As a post person I don't want the production mixer playing with levels during recording.

The catch comes on big budget films where the mixer is mixing a scratch track for the dailies. In that case I want them to do discrete tracks with out a bunch of level changes for me and they need to do a mix version for dailies. If you use a set and forget for the dailies they will probably sound not great and you might get your backside handed to you.

And while it may seem like production folks are taking the easy way out and passing it to post, the reality is that it's going to post and our life is easier if the production tracks don't have levels being ridden. Or EQ, or compression, or etc.

Some times you have to, but generally you can get it right in rehearsal and go with that. A limiter for the surprise burst and you are generally good. It also helps if you record 24 bit.

Anyway that is what I think is happening. In analog you had to pump up low sounds to get them out of the mud, but today I can lift them up in post and there really is no mud to worry about.

This does NOT mean you can record really low all the time, you still need to get decent signals, but if you are where you should be then someone getting quieter should not be the problem today that it was in analog days.
 
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