View Full Version : A-T899 lav a bit "hissy"


Jonathan Levin
April 7th, 2015, 01:10 PM
His everyone.

I just received a new A-T899 lav and I am somewhat underwhelmed.

My previous testing were with none lav mics: a Rode NT3 which sounds REALLY good, very little hiss. An older Beyerdyanamic shot gun which has a bit more hiss.

The new A-T899 seems to be kind of "hissy" with the selector switch to either flat or roll-off. I personallly like the sound of flat (the straight line) seems more full.

Any advice? I have the lav mounted about 7" away from chin.

Sorry for using hissy for lack of the correct term.

Thanks.

Jonathan

Don Palomaki
April 7th, 2015, 02:05 PM
No surprise based on the mic specs.

The NT3 is about 4 dB more sensitive and perhaps a ~6 lower noise floor (if I am reading the specs right). Not surprising considering the NT3 should have a larger much larger diaphragm.

Maybe apply some equalization/filtering to knock out the non-voice frequencies.

Jonathan Levin
April 7th, 2015, 02:24 PM
Thanks Don.

I've gotta tell you. I'm thinking that I may return the lav and just boom in my Rode. The sound is so much better! The A-T sound is almost unacceptable to me!

If I were to spend more money than $260.00 on a lav, would that buy me any better quality. Is there such a lav that has a better "noise floor" than what I just bought?

Thanks.

Jonathan

Jon Fairhurst
April 7th, 2015, 03:28 PM
I used to have an AT-803b lav, which is the cheaper, larger brother of the AT-899. And yes, it was noisy. It was fine for live presentations, but not for audio capture. Of course, a good preamp matters, but even with a fixed Mackie mixer, it hissed quite loudly.

I now have the Sanken COS-11D. It's on a completely different level. Love it!

The nice thing about a lav is that for $500-ish, you can get a best-in-class product. Boomed mics (shotguns and hyper-cardioids) cost quite a bit more at the sharp end of the market. Add a nice pole and wind protection and it adds up.

FWIW, I find headphones to be similar. Top monitors can really set you back and then you need to consider stands and room treatment for a really great result. Top headphones cost $100 - $300 and you never have to consider upgrading. (Disclaimer: headphones don't effectively replace monitors for mixing purposes.)

Anyway, lavs a headphones are two categories where the budget shooter doesn't have to compromise.

Jonathan Levin
April 7th, 2015, 03:46 PM
Thanks Jon.

I am using the AT899 through a Shure FP33 and recording out to a Marantz660. And recording in a controlled room environment, complete with sound (moving) blankets to help keep room a bit less noisy.

I have been having some luck using just a touch of the Audio Low pass filter in FCP X for stuff recorded with the 899. Seems a little better.

But looking for any other recommendations too. I'd be willing to spend upward to $450 if it were to make a great deal of difference.

Bruce Watson
April 7th, 2015, 04:43 PM
If I were to spend more money than $260.00 on a lav, would that buy me any better quality.

Oscar SoundTech. (http://oscarsoundtech.com/) Much better value than the AT IMHO.

Jon Fairhurst
April 7th, 2015, 05:00 PM
There are two things that contribute to noise: the sensitivity and the self-noise.

Low sensitivity mics stress preamps. They put out a weak signal, you turn up the preamp gain, and you get noise. With a strong signal, a quiet preamp isn't quite as important.

AT899 sensitivity: Phantom: -43 dB (7.0 mV) re 1V at 1 Pa
Battery: -46 dB (5.0 mV) re 1V at 1 Pa

COS-11D sensitivity: 17.8mV/Pa (-35dB,0dB=1V/Pa)

That's significant as your preamp noise will be 8-11 db higher with the AT than the Sanken. Then again, your preamp looks like it can handle it.

The self noise is harder to compare:

AT899 signal to noise ratio: 64 dB, 1 kHz at 1 Pa

COS-11D Equivalent noise level (A-weighted): 28dB-A

Off the top of my head, I'm not sure how to compare these two specs.

What I do know is that the difference between the noise (28dB-A) and max SPL (127 dB) of the COS-11D is 99 dB, which is a significant amount of dynamic range.

Of course, a key contributor to noise is a low signal. If the mic is far from the talent and/or they speak softly, this can be a major cause.

In any case, with the COS-11D, I don't recall ever needing to use noise reduction when coupled with a decent preamp. it's been a rock solid purchase.

An important consideration is the use case. If you will plug it into a wireless transmitter, you can get a less expensive version with the correct plug. If you want an XLR output, you will need to get the more expensive version that includes the power module. You can't just hook it up the cheap version with a cheap, 3rd party XLR adapter. In my case, I went with a TA4 connector and I wired the power adapter to a female TA4. This lets me wire various adapters. Then again, I've only used it with the XLR, so I added more complexity than I really needed...

Jonathan Levin
April 7th, 2015, 05:18 PM
Bruce I'll look further into the oscarsoundtech. Are those the lavs that I've read about that are made to order?

Jon- thanks for the WAY detailed reply. Let me ask you this: the 899 came with a capsule/connector that holds a AA battery for non phantom operation. Would the noise diminish any if I just used phantom power? My mixer is set to phantom for the channel i was testing the 899, and I'm guessing that if I have a battery powered device connected it will cancel out the phantom power from mixer.

You had some figures that had phantom verses battery, a bit beyond me😗

Thanks guys.

Jonathan

Rick Reineke
April 7th, 2015, 06:21 PM
"I'll look further into the oscarsoundtech. Are those the lavs that I've read about that are made to order?" - Not sure what you mean by "made to order".. the OST mics can be configured with a connector of your choice. Mine are with plugs for my wirless transmitters and additional XLR Phantom Power adapters that take the place of the transmitters for hardwired use.

With dual powered mics, the Phantom Power option normally yields better S/N specs and higher SPL handling than with a battery.. it's certainly not night and day though. If using Phantom Power, I would remove the battery all together unless there's a switch. I have some older AT899s (originally for use with my Lectro 211s, I've never noticed a noise problem and post never complained either. I don't much like the 899's stiff cables though, I understand the latter model cables are better.

Have you checked the downloaded files though a pro sound card and good studio monitors.. The 660's HP amp is under-powered and inherently noisy, probably even through the FP33's return if it's cranked.

Jay Massengill
April 7th, 2015, 08:39 PM
The AT899 kit also includes a small cap with a wire screen that snaps onto the mic. I think this reduces the high frequency response of the mic, which is fairly bright sounding.

I almost always use my AT899's with both the cap in place and the tiny foam windscreen, which also makes it a little less bright.

I keep the rolloff switch in the flat position most of the time.

I would try running the mic with just phantom power and no battery in place at all.

And as mentioned, check the recorded files on good speakers.

Also make sure you're set to a realistic practical recording level. It's easy when testing to crank up too much gain listening for the self-noise of a mic.

That said, almost any lav will have higher self-noise than a quality larger-diaphragm mic in the same price class.

Don Palomaki
April 8th, 2015, 05:38 AM
Also, any hiss will usually be more apparent when listening with headphones as opposed to speakers.

You may be able to reduce the hiss a bit using noise filtering in audio editing programs such as Audition. But use a light touch to avoid adding other artifacts in the sound. Also, using noise gating may help suppress the hiss when there is no other sound/voice present.

I believe that the equivalent noise level translates to the sound pressure level required to provide the same output.
That would imply a S/N (at 1 Pa) of about 94-28 = 66 dB, for the 11D, about 2 dB better than the AT, but that is likely less than variation within a production run. Published figures are often weighted and may not account for production variations in individual models or aging, so use the specs as a starting guide, and conduct listening tests to decide.

Phantom power might give lower noise floor, and it might not. Give it a try.

However, keep in mind that no background noise is an unnatural state and might sound a bit strange, so strive to reach an acceptable level.

Jon Fairhurst
April 8th, 2015, 11:22 AM
So it seems that while the sensitivity is much better, the self noise is fairly similar for the two mics. (Then again, if you need 10db more gain due to sensitivity differences, does the self noise also increase by 10 dB. I'm not sure how the specs couple.)

Of course, specifications are just a guidepost. While I generally trust AT and Sanken, the test methods may differ, the companies might apply more or less margin for their printed specs, and individual units may vary. More than that, some sounds and noise are natural and attractive, while others are ugly. Specs don't reflect the subtlety of human perception.

As an example, I bought an Avantone Pro CK1 purely on good specs and a low price as I couldn't find any detailed reviews. On paper, the CK1 is roughly on par with an AT4053b, which is relatively well regarded. As it turns out, the high noise of the CK1 makes it unusable.

I RECOMMEND ***AVOIDING*** THIS MIC>
Avantone Pro CK-1 Small-Capsule FET Pencil Microphone CK1 B&H

Anyway, specs are a good starting point and can identify products that don't suit a given use case. They can tell you when a product is unsuitable or bad but don't necessarily tell you if a product is great.

Jonathan Levin
April 8th, 2015, 11:33 AM
Thanks you so much! I have not responded because I am going to run some more test this afternoon as was suggested:

1) Remove battery, just use phantom.

2) Try using supplied wind screen attachments.

My thinking is that with something this tiny, how can it compete with a big honking diaphragm mic like the NT3 or even a shotgun as was mentioned above.

Maybe it is what it is, but I will most certainly try some more things out and report back.

BTW- I was actually off loading the sound files to computer and listening to them on a better sound system than the HP out from the recorder. I wonder how much noise is acceptable, If the dialog wasn't 20 minutes, I could run some ambient music to the background which would take away from the distraction. Or maybe I'm being to picky....

Seth Bloombaum
April 8th, 2015, 01:11 PM
I am using the AT899 through a Shure FP33 and recording out to a Marantz660.
Definitely try the mic straight into the 660.

Hypothetically, a mic that requires more gain in the mixer could be exposing self-noise in the *mixer* that you haven't heard with hotter mics.

Don Palomaki
April 8th, 2015, 01:47 PM
The self noise of the condenser mic may be a bit like the noise level in CCDs, - as the area of the sensor (diaphragm) doubles the output doubles while the self noise contribution of the diaphragm increases by a factor of about 1.4, other things being equal. And of course, some mics will have better electronics than others.

The output (sensitivity) of the condenser mic is in part driven by the gain of the internal amplifier in the mic. These are design decisions by the manufacturer.

For typical mic specs, the noise floor equivalent should be the S/N ratio dB below the 1 Pa output level. But some mics rate their output at 0.1 Pa sound pressure.

Jon Fairhurst
April 8th, 2015, 03:28 PM
For lavs, I believe that the smaller size reduces the output at low frequencies but not necessarily at high frequencies. Turning it around, I need a big woofer to create powerful bass, but a small tweeter or compression driver can create piercing high frequency sounds.

So, it depends... If the manufacturer EQs the smaller mic to deliver stronger bass frequencies, the noise will increase with the bass boost. If they allow more LF rolloff, there won't necessarily be additional noise, unless you boost the bass in post.

Note that some say the larger AT803b sounds better than the smaller AT899 because of its superior bass response. The AT899 is more expensive because it's more difficult to engineer good sound in the smaller package, not necessarily because of better sound.

Interestingly, the Sanken COS-11D uses a lengthwise plane as its diaphragm, rather than a circular or end-address diaphragm in order to get a large surface area in a small package.

Here's an excellent blog post where the author takes one apart and shares the photos:
Sanken COS-11 Lavalier Dissection - Audio Signal Generator - txsound.com blog (http://www.txsound.com/blog/sanken-cos-11-lavalier-dissection/)

Jonathan Levin
April 8th, 2015, 03:41 PM
Thanks for your help. I've run a few tests: All tests were reviewed on system. Mic position on t-shirt about 4 inches from chin, was able to reduce levels a bit.

1) Lav with supplied "Element cover" and with "element cover" and foam wind screen. After performing a test just to see if there was a huge difference between using the "element cover and the foam or just the element cover, I concluded that I couldn't tell to my ears much difference, so I did the rest of my tests with just the element cover.

With roll off (please correct me if I am not using the right terms) set to flat ____ and then set to /----. (Dashed line should be at top of leaning line) Flat is definitely boomier but /---- was to thin. Something in between would be nice, but nothing I couldn't adjust in post using either setting.

AA Battery was IN the connector capsule but everything plugged into a phantom powered input on mixer.

I still had a bit of hiss but I also recorded with levels down on the mixer a bit as well as on the recorder. No clipping occurred except when my chin rubbed mic when I went to look down for something.

2) I also tested the same as above but I removed the AA battery from the capsule and just ran on Phantom. Interestingly, the mics gain seemed to increase just a bit without the use of the AA battery.

I'm starting to get a good feel for this mic. I'll probably keep it and use it with the "element cover" in place since that did make a difference from the tests I did with nothing on the lav.

I also need to dance around with my settings on the mixer, I may need to go a little lower as well as on the recorder.

My question for you: Is it better to record with the roll off set to flat _____ and adjust a little of the boom OUT in post, or is it better to have the roll off set to /---- and adjust MORE low end in post? Or does it not matter?

I'm going to need a few years to understand some of the lingo you guys know.

Jonathan

Jon Fairhurst
April 8th, 2015, 04:25 PM
Indoors, I would set it flat. Outdoors, I would use the low cut to reduce possible wind noise. The low cut will help prevent your preamp/recorder from overloading during bursts of wind, plosives, etc. If you don't cut at the mic and clip the recording, you can't recover it in post.

In my experience, the EQ depends on how the person matches the mic. If you have multiple people speaking, you might need to add some EQ to give the voices similar weight. I do this by adjusting the low shelf and working on the 200-300 Hz range, which is roughly the fundamental frequency of the human voice. If one person booms and that boom matches a strong spot for the mic, they can sound too full. If another person has a weaker voice and their fundamental hits a low spot for the mic, they can sound especially thin. Matching overall levels and then working in this range to match multiple speakers works great.

Other important frequencies:
* At 100 Hz, you can boost the music and sfx without bumping into dialog.
* At 200-300 Hz, you can cut the music to make room for the voice fundamentals described above.
* You can cut the voice broadly around 600 Hz to make room for music and sfx.
* Around 1200 Hz is important for consonants and clarity. Boost as needed. (You can cut the music in this area.)
* 2400 Hz is in the region of nasal tones. Adjust this area to tame a harsh voice or add life to a dull one. Note that a heavy cut here will make a flute, oboe, or clarinet all sound similar. Same for voices. If two characters sound similar, work on this area to differentiate them. This is where golden ears really earn their money. (My ears are bronze at best!)
* 5k - 15k is "air". Boost this to add freshness to a voice, but too much will boost noise/hiss.

I find that this simple guide helps me to do basic EQ quickly and effectively. Masters of the art are able to fine tune things precisely within those regions. When I try that, I'm slow and I'm not quite sure if I'm making things better or worse. But at least I can work the larger regions okay. :)

Don Bloom
April 8th, 2015, 06:33 PM
Jonathan, one thing you mentioned in your first post was the mic was about 7 inches from the mouth. In your last post you said you had it about 4 inches.
Now I'm no expert but I was taught many years ago that a lav really should be about a fist down from the talents mouth. IOWs, make a fist. Place it to the talents chin and at the bottom of the fist is where the mic should be. It's always worked for me.

Jonathan Levin
April 8th, 2015, 06:53 PM
Jon, thanks for that info. I really need to go back and review Jay Rose's book on audio about all this Hz and frequency business. Kind of embaressed I am having a hard time understanding a that.

Right now I am going with my ears and the meters on my devices, making sure I stay well away from the 0dB/Red on those. And then I do a thorough review on a computer audio system. A mixer with a built in recorder makes things a whole lot less complex in my book.

Don- yes that seems about right, my fist is about four inches. When ever I watch some news show or program where a speaker is wired with a lav, I ways like to see how far, which direction (up or down), windscreen (even indoors), no windscreen, lots of variation. And obviously depending on which way talent is speaking dictates right or left placement.

Jonathan

Jon Fairhurst
April 8th, 2015, 11:12 PM
I place a lav at the 2nd to the top button on a shirt at the highest. The problem with higher mounting is that the audio varies when the talent turns their head. One could vary it for the talent/genre. A stoic person in an interview could do fine with a high mic. An animated person in an action film wide shot would merit a lower position.

From memory, doesn't Jon Stewart wear his mic at roughly the third button?

Rick Reineke
April 9th, 2015, 09:42 AM
The definition of "hiss" is usually associated with BG noise (as in tape hiss) and that's what I assumed. But I gather Jonathan means 'sibilance'. So yes, move the mic up closer to the wearer's chin and use a windscreen. In audio post, a de-esser is a common tool to further control it.
Except when wind noise is an issue, a HP filter is usually not needed on lavalieres due to their inherent frequency response.

Jonathan Levin
April 9th, 2015, 10:30 AM
Rick,

Thanks. This may be a very dumb question, but when you say a HP filter (assuming that means high pass) is that the same thing as the term roll-off, the (flat)_____ or /----- setting? Or something completely different.

Howe do you guys keep from going insane?

JL

Rick Reineke
April 9th, 2015, 12:23 PM
Yes, the same as 'low frequency roll-off or rumble filter.. I've seen lots of different names and have even seen it notated in a camera's menu as.. 'wind'. ..

When I was a music recording engineer, clients used to always ask, "what's 'PFL' stand for"? (pointing to the channel button on the mixing console). My response.. "pretty f___ing loud" . (a little audio humor)