I own an H4n and an H2. I put two pairs of recordings (made simultaneously with the microphones as nearly in the same location as possible) from the two recorders here:
http://www.mediafire.com/?sharekey=a1be82c87c7e349cd9d5c56d04dfa8b02a7792592a9a57a6947708e37b913e74
Unfortunatly, neither is a recording of a whistle.
To me it’s obvious that the H2 has a lot more noise and the H4n records a
lot more detail. The recordings were made in 44.1 khz 16bit wav files and
are unedited in any way, except for length.
The H2 is really, really good, but the H4n is spectacular.
The H2 is more than sufficient for recording sessions, lessons, and workshops.
My H4n came as a package deal with a microphone stand. It included an adapter that goes from microphone stand threads to 1/4" thread.
Earlier in this thread someone said that the h4n has four microphones built in, but this is incorrect.
One really handy feature the H2 has is the sensitivity switch on the side. I leave the recording level set at 100. The low sensitivity setting is then perfect for recording bagpipes, while the high setting is perfect for violin. The H4n does not have this feature, and you have to set recording levels. One handy feature of the H4n is the speaker. It’s great to be able to hear your prhasing without needing to put in earbuds.
The killer feature of the H4n is the 48v phantom power on the XLR inputs.
The H2 is small enough you can put it in a shirt pocket and the microphones face outward. It will also stand on a table. And the 360 degree recording technology sounds really cool for a session, but I lack four channel output on my PC, so I’ve never tried it out.
After my wife and I got the H2, we found that both of us were wanting to use it on a regular basis, so we decided to get another. I figured there was no point to having two of the exact same recorder, which is why I got the H4n. I think I use the H2 more often when I go someplace, and the H4n more at home.