Improving the sound of a real piano recording

Dear Friends,

I have attached a brief recording of my daughter playing our piano. I am trying to make the sound more crisp and less muffled. Can anyone give me any idea on how best to do this? I used the first three seconds of audio as criteria to remove any background noise. I just cannot determine what filter might clean up the muffled sound.

Thanks in advance,
For the Beauty of the Earth - piano help.aup (1.19 KB)

There is no audio in your attachment. You could try attaching a 3 second .WAV file in a ZIP file, or posting a link to audio on a file-sharing website.

If there is a bit of your recording only with noise (no piano) you can sample some of this noise and subtract it from the recording using Audacity’s noise removal feature {before/after example attached]. I strongly suggest using Audacity 1.3 rather than 1.2 to do this as 1.3 noise reduction is much better. Boosting the higher frequencies using Audacitiy’s equalizer will give a brighter, less muffled sound.
Hissy piano (original then cleaned with Audacity 1-3).zip (333 KB)

Audacity doesn’t save sound files. An AUP file is a project manager, not sound.

While we’re waiting for that, describe the room, microphone and other capture details. Model numbers are good. Sound mixer?

What type of piano is it? Size? C7 concert grand Yamaha?


We never explained what you did wrong. The only way to get a real sound file in Audacity is File > Export. Not Save.


I am sorry the sound file was not attached. I attempted both a .wav and .mp3 file and receive a “the extension … is not allowed.” Any ideas on what I am doing wrong?

I have the following equipment:

Eurorach UBB02 mixer
S8 2 Zs Soundblaster Augidy PCMCIA card (laptop)
MXL 990 condenser mic

The piano is a Kawai upright grand

I have already gotten rid of the noise … it is the muffled sound that I am attempting to clear up.

Thank you, in advance, for your help.


If you put the wav or mp3 in a ZIP file it can be attached, (like I did above), provided it is less than 500Kb, (i.e. only about 3 seconds worth of CD quality audio).
As you have found posting files in a .wav or .mp3 formats directly is not allowed in this forum.

To allow people to hear longer sounds you could post the audio on a file sharing site and post the link to the audio here.

Re: muffled sound. Audacity has a graphic equalizer option, like a stereo, you can experiment with the sliders to improve the sound quality.


There should have been very little noise in the original recording and it should not be sounding muffled. With the equipment that you are using the sound should be clear and clean without doing anything, so we need to go back a bit to see what is wrong.

Let’s start with the laptop computer - what operating system are you using?
The microphone is a condenser type - these usually require phantom power - where is the power for the microphone coming from?
Which version of Audacity are you using?

The piano is an upright acoustic piano? Is that in your living room? Carpeted with lots of soft furnishings?

what operating system are you using?
The microphone is a condenser type - these usually require phantom power - where is the power for the microphone coming from?
Which version of Audacity are you using?

The piano is an upright acoustic piano? Is that in your living room? Carpeted with lots of soft furnishings?

I am using windows XP Pro. The power from the mic is coming from an electrical outlet. I am using Audacity version 1.2.6. The piano is in my living room (hey, have you come to my home?? :slight_smile: ) Yes, there is carpet and it is against a wall. Furnishings? Yes. The microphone was placed on the floor (on a small stand) on the side of the piano.

I have attached a ZIP file of the audio file. Thanks for letting me know that ZIP was the file type I should have used to upload the music.

For the Beauty of the Earth - piano (290 KB)

mjwillyone piano before and (316 KB)
I can hear some weird phasing-like effects in the above : this can be a result of overdoing the noise removal, (I’m not guilty),
I just amplified it and boosted the higher frequencies (3000-5000Hz) by about 6dB.

Below is a schmaltzy pseudostereo version with a bit of reverb
mjwillyone piano - schmaltzy remix (pseudostereo).zip (170 KB)

Wow … what a difference. I am new to Audacity, but will try to find out where the controls are for doing what you did.

Thank you so much! I really appreciate it.


In Audacity 1.3 “Amplify” is at the top of the “Effects” list. Select the section of audio you want amplified, then click on “Amplify”, then “OK”, simples.
Then use Audacity’s (graphic) “equalization”, (10th from top of “Effects” list), to boost the high frequencies, (experiment with the sliders).

[As I mentioned above you may have overdid the “noise removal”: there are some weird side-effects there which I cannot correct}

Which is basically what I was going to do, but carried off much better.

How did you get rid of the “noise,” and in which Audacity?

I hear phasing caused by a small living room. I know this because this is exactly what my upright grand sounded like in my living room. Some of the notes are way too pronounced compared to the others because those are the notes that the room “likes.”

But much more deadly is the reverb and echo. You can pour additional echo chocolate sauce on top and hope nobody notices, but your rose and beige wallpaper, Agatha Christie collection, and paisley divan are always going to be part of your performance.

The microphone has a cardioid pattern. Can we assume you can’t turn it off?

We need to congratulate you on not making any of the other common mistakes; overload, clipping, channel noise, etc.

Make another recording, this time without the instrument. Sit in the players position and clap a couple of times with maybe three or four seconds between. I’m after a good solid pop with your hands, wait, pop. You may need to reduce the channel gain so as not to overload anything. I’d like the whole performance from a couple of seconds before to five seconds after.


Is that serendipitous or what…

(stiff download).

Please excuse the noisy transmission. I’ve been going back and forth between the two. The Real Thing is a Steinway in Lincoln Center, so that’s the gold standard. I think a lot of the mush in the posted sample is the room. You can’t get crisp notes in a very echoey hall or a live room.

In spite of being a smaller instrument, the posted sample bass notes are way louder than the standard. This can be caused by instrument design…or a live room.

Plus, I think there’s channel distortion on top of everything else. That’s why the notes sound harsh compared to the pro recording. The 990 microphone is $49. It’s a copy of a Neumann at $4000.

Large cell condenser microphones do have interesting problems. They don’t much like sound coming in from the sides. Anything not arriving straight on to the capsule causes ripple distortions. Building and shielding that capsule is a major industrial secret.


How exactly? According to the manual, “This unit requires phantom power at 48 volts, +/- 4 volts.” So what is providing the 48 volts - are you getting the phantom power from a mixing desk, a special microphone power supply, a microphone pre-amp…? (It can’t be coming from the laptop, and it can’t be coming from a normal wall outlet socket, so I’m left wondering where it is coming from).
[Edit] Oh, hang on a minute - you said that you have a “Eurorach UBB02” - I guess you mean a Behringer Eurorack UB-802 ? That would make sense - you have phantom power switched on from the UB-802 mixing desk.

Not ideal - you need to get the microphone up higher (try lying on the floor and listening to someone playing the piano - it doesn’t sound as good as when you are sitting at the piano, or listening from across the room. Much of the natural timbre (and volume) will be lost if the microphone is too close to the floor.

There are many techniques for mic’ing upright pianos depending on the kind of sound that you want and what you have available. Some people like to open the top of the piano, or even take the entire front off, while others prefer to keep it closed up. I presume that you normally play with the piano lid closed and that it sounds good in the room when you listen “live”, so I would probably record with the lid closed (though I may just try it out with the lid open to see how it comes out).

A common microphone arrangement is to use a pair of omnidirectional small diaphragm condensers quite close to the piano (1 to 2 meters away) and a large diaphragm condenser further back in the room (works nicely for pianos in big rooms - you can adjust the amount of “room ambiance” by adjusting the mix). With just a single microphone in a modest sized room I would try placing the microphone in it’s cradle (spider) on a full size microphone stand, so the the microphone is just above and behind the head of the pianist (so that it is “listening” over the pianists head). This should give a close approximation to what you hear as you play, and with the equipment you have should give a sufficiently detailed sound that we can hear the pianist breathing, hear the leather on the piano stool creaking, and hear if the pianist has not cut their fingernails short enough.

For the Beauty of the Earth - piano

Not quite there is it. The amount of noise reduction has caused very noticeable wobbling in the sound - noise reduction should be virtually unnecessary for this kind of recording - what sort of noise are you getting? is it hiss?
[Edit] Now I’ve twigged that you are using a UB-802, make sure that you have the microphone gain set at a high enough level (but not turned up to maximum). You should be getting a meter reading on the mixer of up to 0dB with the volume sliders set at zero (centre position), then adjust the recording level of the sound card (use the “Line in” on the sound card) so that you get around about the level (or perhaps just a shade higher) than the audio sample that you posted. With all the gain levels set correctly and the microphone positioned higher the raw recording should sound very much better. (nice piano playing by the way)

There is one more possibility. An old staging trick is to put the microphone upside down so the capsule is only a half-inch or so from the floor. That will dramatically reduce one source of echo (the floor) and double the loudness of the signal. The theatrical version of this is the foam blobs on the floor just beyond the footlights like the EV Mic Mouse.

Page 3, Figure 5.


Learned books have been written about how to mic a piano, this isn’t a simple problem.

I don’t think that is likely to be a suitable solution in this case because the floor is carpeted and will probably produce rather muffled results due to the carpet absorbing the higher frequencies. It is very likely that this is one of the reasons that Mikes original recording is lacking at the high frequency end.

The basic idea that you describe there is nevertheless valid. In my previous abode I had a pair of PZM microphones permanently glued to the ceiling in the living room and achieved some very nice “ambient” recordings of ensembles with a minimum of fuss setting the recording equipment up (just plugged the microphones into my Sony 1/4" tape recorder, switched on the microphones and start recording).

A lot of the difficult compromises arise when the job in hand is sound reinforcement. In order to achieve a high degree of amplification it is usual to mic up the sound board. This will tend to produce a less natural piano sound, but the type of sound that has now become so familiar that makers of electronic stage pianos will often model the sound on a “Mic’d up piano” rather than on a real acoustic piano.

Microphone positioning makes a huge difference to the final recording. As you say Koz, there are many learned books on the subject, but when commercial pressures and time constraints are not an issue, a lot can be gained by experimentation.


Perfectly true, but you can help that in post production. What you can’t fix in post production is the comb effect caused by the echoes. See page one of that document and that, to my ear (what there is left of it), is the most damaging part of the performance.

Not the player. That part is fine.

Listen to the difference between the Lincoln Center performance and the posted one. The high notes are respectable on both, but the mids and lower make my ears bleed.

Still waiting for that clap…


I suspect the comb type effect that you can hear in Mike’s clip is caused by Noise Removal rather than the acoustics of the room. It would be helpful to hear a “straight” (unprocessed) recording. In well damped rooms (carpets and soft furnishings), comb effects are usually barely noticeable, whereas in that recording they are very pronounced, which makes me suspect that the cause is something other. There are also other tell-tale signs of not-so-subtle Noise Removal.

Will do (not listened to those yet).

I hope that we hear from Mike again - there’s a lot of good information here and it would be nice if he was part of this discussion.

<<comb type effect that you can hear in Mike’s clip is caused by Noise Removal>>>

Did we ever establish if he was in Audacity 1.2? I, too, would kill to get a straight capture.