how to attenutate signal before mic
how to attenutate signal before mic
(OP)
I want to record the sound of machinery on my Android phone. The main purpose is just to build a catalogue of sounds we have heard, so we can be more familiar with what's normal and what's not, and what a machine sounded like a year ago. Getting a good quality recording that sounds like the machinery is therefore important.
I have tried several of the programs available on Android, including:
PCM Recorder
Virtual Recorder
Tape Machine
One thing I find is that all my recordings end up with clipping because the environment (inside a machinery building) is too loud.
None of the programs has an input limiter. (Virtual Recorder and Tape Machine imply they do, but they really don't. Closer review of Tape Machine website explains why: the hardware controls to perform input limiting are not available to the Android programs).
So, I would like to try to reduce the signal before it gets to the microphone.
I can't move away from the machine, because that just tends to make the signal/noise ratio go down (I hear more background noise and less of the machine I'm interested).
So I'm thinking maybe I would put something over the mic. A piece of paper? A piece of masking tape? A cotton ball taped over? What would you suggest that might attenuate the signal but hopefully not distort the noise too much in the process?
I have tried several of the programs available on Android, including:
PCM Recorder
Virtual Recorder
Tape Machine
One thing I find is that all my recordings end up with clipping because the environment (inside a machinery building) is too loud.
None of the programs has an input limiter. (Virtual Recorder and Tape Machine imply they do, but they really don't. Closer review of Tape Machine website explains why: the hardware controls to perform input limiting are not available to the Android programs).
So, I would like to try to reduce the signal before it gets to the microphone.
I can't move away from the machine, because that just tends to make the signal/noise ratio go down (I hear more background noise and less of the machine I'm interested).
So I'm thinking maybe I would put something over the mic. A piece of paper? A piece of masking tape? A cotton ball taped over? What would you suggest that might attenuate the signal but hopefully not distort the noise too much in the process?
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RE: how to attenutate signal before mic
The simple theoretical answer is that you need an expansion box, whih would be dead easy to build, and easy to calibrate. ie small big small
I'm thinking a coke can and a couple of bits of 1" waterpipe.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: how to attenutate signal before mic
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RE: how to attenutate signal before mic
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: how to attenutate signal before mic
Walt
RE: how to attenutate signal before mic
- Steve
RE: how to attenutate signal before mic
There is no microphone input jack. There is some kind of multi-purpose headset jack that may suit the purpose if I can figure out the right adapters. If you have a known working solution for Android, I'm all ears.
In the meantime, why is it crazy to attempt to attenuate signal at the mic?
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RE: how to attenutate signal before mic
I am sorry that I read your post too quickly, and I thought that a remote microphone or sound meter was being connected to the phone. As an aside, I have been looking for a new phone and reviewing apps for audio recording and analysis. The Android apps features looked pathetic compared to the iPhone apps. I am still looking.
Walt
RE: how to attenutate signal before mic
I am in agreement that attenuating the sound in front of the microphone is likely to affect sound quality. The things I have tried have not worked so far. Like putting my finger over the mic, putting napkin over mic.... these prevent the clipping but don't give good sound. But you never know... haven't tried the muffler trick yet (although it would be a challenge to seal the end of it against the phone).
Many of the programs feature fancy recording specs like 44,000khz. But I'm not sure whether this phone has good analog recording circuits to go with that. Some quick recordings in a quiet environment showed quite a bit of static also. Maybe a separate mic would help... I'll try if I can find one.
It may be that it is just not up to the task. But worth a try to explore the capabilities imo.
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RE: how to attenutate signal before mic
Unfortunately, I'm not sure if those harmonics of running speed shown are real or (more likely) just a figment of the chopping. The recorded sound in this case sounds nothing like the original.
The waterfall format from AndroSpectro will be a very handy tool if only we could get good recording quality. A big if.
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RE: how to attenutate signal before mic
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: how to attenutate signal before mic
44.1kHz is the standard for CD recordings, so I'm not surprised it's used by the fashion accessories. 48kHz had its day, but I'm not sure if DAT is still alive.
- Steve
RE: how to attenutate signal before mic
Once could be viewed as an attempt at humor, however uninformed and irrelevant the comment is with respect to the current thread.
Twice can only be viewed as a troll.
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RE: how to attenutate signal before mic
- Steve
RE: how to attenutate signal before mic
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RE: how to attenutate signal before mic
http://
I keep an eye on phone audio apps, but so far I have not been too impressed. I bought a Sony Linear PCM-M10 digital recorder that is similar size, but thicker, than an iPhone, but it has much better audio quailty.
Walt
RE: how to attenutate signal before mic
The PCM-M10 looks to be around $250. The built-in mic is omni-directional which would not be ideal for most of my recordings in noisy place. Do you use an external mic?... what kind?
I did find this you-tube video with brief explanation of how to hook up external mic to smart-phone:
ht
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RE: how to attenutate signal before mic
http://www.ikmultimedia.com/irigmic/features/
$50-$60.
* highly unidirectional mic
* Three levels of gain.
* Then there's this - "The iRig Mic condenser-electret capsule with accurate unidirectional pattern and high-pressure holding ensures high-quality crisp, clean vocal reproduction - even in noisy environments - with no distortion, even with the widest range of volume dynamics."... not sure what high pressure holding is but no distortion over a wide range including noisy sounds good.
* The plug-in connector shown (with the 3 dark bands separating 4 conductors) is the same one that plugs into my Android phone (Samsung Infuse). Certainly will work with iPhone... looks to me like it might work with Android...
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RE: how to attenutate signal before mic
Walt
RE: how to attenutate signal before mic
Google Search: "external microphone for android phones"
Agood link is here:
http
Walt
RE: how to attenutate signal before mic
htt
which compares three more for iPhone with similar connector, and small:
Vericorder MiniMic:
http://vericorder.com/products/minimic
Brando Mini Capsule Mic:
http://
Blue Mikey:
http://www.bluemic.com/mikey/
My Website: http://dizzydougtv.com
My Twitter: http://twitter.com/DizzyDoug
My Facebook: http://bit.ly/cL0nH9
I saw these first, but I like the iRig better because of the specs. Small would be nice, but low-price and good quality are higher on my list. The plant is 100 yards from my desk... not a big deal to carry a mic that far.
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RE: how to attenutate signal before mic
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RE: how to attenutate signal before mic
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RE: how to attenutate signal before mic
I could not get mic to record in any software (including making a phone call)... my phone (Samsung Infuse) seems to always use built-in mic's and ignore the connected mic.
I have heard of some who successfuly used external mix with Android
http://www.youtube.com/watch?v=pCnv1SUMoNI
But I could not get it to use the microphone even using the same software as used in that video (LG camera appp... tried all 3 settings of the microphone input setting in that app).
Seems like some other Android phones may have similar problem:
http:/
I don't see any external mic in my near future.
Thanks for the comments.
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RE: how to attenutate signal before mic
Ted
RE: how to attenutate signal before mic
Ted
RE: how to attenutate signal before mic
Walt
RE: how to attenutate signal before mic
Voodoo sound software gives a lot of useful recording capabilities for Samsung Galaxy S series phones (including Infuse) that should overcome the problems mentioned above. Apparently the capabilities are there in the phone, they just need low level programming (like this voodoo software) to get at them.
Here are some of the capabilities the software provides:
1 – gives the ability to hook up an external microphone
2 – includes several software presets that give varying attentuation for audio input from the phone (from phone mic or external mix)... basically 3 levels: hi, medium and low sensitivity.
Two versions of the software are available
Voodoo sound plus
https://play.google.com/store/apps/details?id=org....
costs $3.50
requires rooted phone (similar to jailbroken iphone)
Voodoo sound
https://play.google.com/store/apps/details?id=org....
free
requires rooted phone
requires custom kernel with voodoo lag-fix / file system
I took the 2nd approach, using Zen’s Infusion A kernel for rooted Infuse phones with Gingerbread OS.
I have done a few early tests. Recorded loud music with phone next to speaker and comes out better on the low-sensitivity setting.
Tried out my $15.00 earbud/mic combo headset, and verified that when it is connected that external mic works as a mic and the phone mic is disabled. I haven’t recorded any machinery yet, but I wanted to update this thread before it gets closed due to age.
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RE: how to attenutate signal before mic
This one definitely true.
[quote]Recorded loud music with phone next to speaker and comes out better on the low-sensitivity setting.[quote]
This I'm not so sure about. There is not a big difference. Maybe the setting only applies when using external mic (?).
Sorry if this is all a little off-topic. I did want to correct possible inaccuracy about behavior when using voodoo sound with built-in mic.
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