Product review - PM40 PianoMic System

Earthworks PM40 review.

I have had the privilege of working with many  professional pianists in both studio and live  performance situations. I have found that to achieve  the ideal grand piano sound it has been necessary to  experiment with various microphones in a number of  different placements. In the studio, where time isn't as  limited, there is more opportunity to try different options  to suit the track you're working on as opposed to a live  situation where it is very hard to get a consistently great  sound from an acoustic piano without incurring feedback  and mic separation issues.

Earthworks have listened to engineers and developed  this single purpose system to mic a piano for churches,  performing arts centres, and recording studios.


The PianoMic System mounts inside the piano across the strings, behind the hammers. The microphones are supported by a telescopic bar that sits on both sides of the piano case resulting in no mic stands being on view, this also allows the lid to be shut if desired. The whole unit is very light-weight, weighing only 350g, but is very strong and versatile. The telescopic bar is adjustable at both ends allowing a bias to either the higher or lower keys, and when fully extended will reach 64" enabling it to fit all grand pianos.

The two high definition, omni-directional microphones are mounted on the bar with exible stems giving you an incredible amount of positioning from what appears to be a very specifically placed rig. The microphones themselves are a continuation of the Earthworks well-established High Definition mic range with an incredible frequency response of 9Hz-40kHz and a high SPL of 148db. The connections from the microphones are neatly laid inside the telescopic bar appearing at one end with a cable utilising a 5-pin XLR connection. Included with the mic rig, in its rather nice ight case, is a box containing low distortion electronics to split the 5-pin XLR into two standard XLR connections.


The rig comes out of the ight case almost ready to go.  You simply extend the bar to fit the piano and position  the mics three inches away from the hammers and three  inches above the strings, as Earthworks suggests for a  good starting point. The cable can be easily hidden behind  the piano and the splitter box can either be mounted on a  short mic stand next to the piano or strapped to the piano  leg in a neat leather pouch. Connect your two XLR cables,  apply phantom power, and off you go.

This layout has all been thought through very well, as it's very adaptable and more versatile than I had first imagined. Everything is all out of sight, which makes it ideal for filming and concert applications. It also permits you to close the lid or to have the lid on either half or quarter stick. By closing the lid it dramatically increases the separation from other instruments or any monitoring in a live situation, or when recording ensembles.

In Use

As you are probably wondering like I first did, when I saw the PM40 it was hard to believe you could get such a good result from miking a piano inside so close to the strings. Conventional miking techniques suggest a piano is best miked from outside. I have played with mics in and around the piano and usually find a ?nasty mush' in the mid range, but the PM40 even with the lid closed delivers excellent clarity. The quality of the sound coming across the PA was very impressive, but better still the sound of the mics in the studio environment was very controlled and clear without the use of any processing. I was also very impressed that the complete note range of the piano could be heard evenly. You may think that there would be a rise and fall in the attenuation of the notes as the pianist plays up to and away from the mics, but this was not the case.

The sound of the piano with the lid closed is a  little more boxy as you would expect, but is still very  acceptable and in some cases more desirable. We had  the lid open whilst testing the Yamaha C6 grand piano  at High Barn ( and I tried raising  the mics as high as the stems would allow and noticed  the natural reverberation of the room was audible.  When the lid was closed and the mics were close to the  hammers, the PM40 gave us a very clear bright rock-piano  sound, which fitted comfortably in a mix for a rhythm and  blues band performing at the venue.

The gain before feedback level of the PM40 is much  higher than anything I have ever used on the stage.  However, the mics have such a low frequency response  to try and capture as much of the image as possible  from the piano soundboard that it's the low frequencies  that feed back first. I can't help but feel that by being  able to change the frequency response and/or the polar  patterns with various price options, the unit would be  more sustainable in the live sound industry. To get the  piano at the level we needed I had to compromise on  the lower end of the EQ. However in my opinion, it did  sound great in the studio and is better than anything else  I've used for live recording.


This is something we've all been waiting for. Earthworks has done an incredible job and for those that are always needing to mic an acoustic grand piano, I believe this is the solution you need. The clarity and versatility of the PM40 is second to none and will surprise the most experienced of engineers. The only thing I would urge you to consider is the price.

web site by island webservices