Thanks Piotr

I should have mentioned that no video is involved here - it's purely an audio recording, which will finish on CD.

(I know there's a Vegas Audio forum, but it's pretty quiet, and I know that there's quite a few knowledgeable audio guys here!)

Peter

In this case, Peter, I guess you should comply to the CD-audio 16/44.1 standard.

I'm sure Bob will help you much better than myself, though :)

Cheers

Piotr

I would record to 44k/24bits, then normalize the audio and dither it down to 16 bits. I'd also use a little Sony or iZotope noise reduction to lower the noise floor a little before I dithered. That way you'll get a full 16 bits of dynamic range without level compression. If you record at 16 bits, you'll need to use a bit of limiting and allow a little headroom. The only way to get the full 16 bits of headroom on the final CD is to record at 24 bits.

If you're only delivering audio CD then my approach is to use 44.1KHz sampling. If you can record that at 24bit then go for it, it gives you a bit more to play around with.

There was a huge discusion about this topic on the audio forum years ago. Convincing doubts were raised about the virtues of recording at higher sampling rates than what you were going to deliver. Bit depth may bring something to the table though.

Kind of like with video. Unless you're doing slomo no much point shooting 50fps if you're delivering 25fps. More bit depth into the image is always a good thing.

The issue with 16bit V 24bit is you need very good mic preamps to really justify 24bit but my approach is kind of 'what the heck, no one has ever said I'll get worse results recording at 24bit and my kit does it easily'

The BIG issue is mic placement. How to mic a grand, now there's a difficult question. And then when you think you have a shot at it the guy playing the piano says to the audience "I'll just close the lid so I can see you guys". Generally grands seem to get miced with two mics, that's what I've observed.

Bob.

Is this a grand piano? If so, I think the best results are with two mics about 8ft away
from the lid and about 4ft apart. Some like to use a piezo such as a Barcus-Berry.
Be sure you work with the music company that tunes acoustic pianos especially
if it is rented. Some contracts stipulate they can't even be moved.

You still need to mic the singer so a small mixer might be needed. Watch the
noise floor on the cheap mixers. Consider renting a good one.

Be concerned more about noise floor than bit rates. I don't have a H4 and
strongly recommend against any MP3 compression. Use PCM from a good
recorder.

Is this a demo for the youth? May not be a budget for renting but try out your
gear before actual recording if possible.

-- I've satisfactorily miked a Yamaha grand with the H4 (stereo mode) about 7-8 feet away. Don't know if this is what you were planning. My recordings worked best with limiting "On."

-- Another approach is one rode on the singer and another on the piano, and use the H4 in the back of the room for a little ambience and applause to be mixed in. Doing it this way, your sync between the dry recording and the H4 recording become a lot less critical in post.

-- This forum has debated the 24 vs. 16 bit thing until everyone was blue in the face. I prefer to keep it simple, and record at the same bit depth and sample rate as my product, in this case 16/44.1. If there some theoretical advantage to processing a 24-bit original down to 16 bit, I've not seen it quantified. (Yes I've heard the effects argument, but why bother?)

The idea behind recording at 24 bits than dithering down is simple. By the time you leave enough headroom so that you don't take a chance on any accidental distortion, you have to record at less the maximum volume that 16 bits is capable of reproducing. You might be in the 15 bit range. You might even go down into the 14 bit range. You need to go beyond 16 bits in order to get the full dynamic range available in this format in your end product.

I agree that in practice, the difference is slight enough that not everyone will hear it, but it definitely is there (even if some of it is buried in preamp noise). The point is that your zoom has the 24 bit mode, you have plenty of room on an SD card, and a 24bit to 16bit dither takes all of about six seconds. Why not go for the best quality your equipment can give you?

I use an Olympus LS-10 which is in the same ballpark sound quality wise. If it was me, I'd pop the recorder on a tripod maybe 10 feet away or so, set the record format to 44.1k / 24 bit, get a healthy but safe level, and record it with the built in mics. Then I'd apply a little NR to lower the noise floor, compress it ever so slightly, and dither it down to 16 bits.

Why not go for the best quality your equipment can give you?

Because the downconversion involves averaging and dithering the bits, the latter being a randomization (noise) that occurs over and above what would be found in a native 16-bit recording; that tends to negate any gains from a slightly higher initial headroom. That's my perspective on it, anyway.

Again, I'd like to see someone with the test capabilities quantify the actual results of downconverting 24->16.

Is this something you can really hear on somebody else's recording without prior knowledge? You actually notice 16 bits of headroom? Mmmm Hmmmm.
I'll bet 1/10th of 1% of this whole forum ever notices any of this except on their own recordings. Most likely from using their eyeballs on some other software to tell them what they're hearing.

Yes, there does seem to be a "more is better" flavor to many of these threads.
I just looked through the 130 or so posts over on the Cineform vx. XDCAM debate and I am amazed by all the hair-splitting that goes on when, like you said, probably no one could tell a difference if they didn't already know which is which.

Kids these days!

Well here's a more practical take on it then. If you recorded at 16 bits, then put it on an album, then put that album in rotation with the rest of your music collection, what you would find is that the new recording was a lot lower in volume than the rest of your music. You would be likely to want to go back and normalize it. After normalization, the new recording would still sound much quieter than the rest of your music because these days there is a loudness war and everyone seems to want to compress the heck out of everything to give it the maximum perceived volume. With that in mind, you would likely want to compress the peaks a little to bring the overall level up. At this point, on casual listening it would still sound fine, but if you listen carefully on good headphones or a nice set of reference monitors, you will find that the sound is nowhere near as pristine as it seemed when you recorded it. If you opened up the processed waveform in Sound Forge, you would see that the curves in the waveforms are not nearly as smooth as they once were.

If you did the same process with 24bit source material, it would still sound crystal clear after normalization and compression and dithering down to 16 bits.

No you won't hear any difference initially between a 16 bit and 24 bit recording. Yes, after a bit of lowering the noise floor with iZotope, light level compression, normalizing and dithering down to 16 bits, you most certainly will. The 24 bit recording will give you much more room to work and will sound quite a bit better by the time your done.

Thanks for the responses guys.

There's no audience - they're performing just for the recording.

I like the idea of two mics for the piano and one for the singer - I have a mixer which will make this easy, hopefully without adding noise - I'll do some tests first.

Rode have some tips in their manual about positioning mics for different types of instruments, so I'll have a good read of that ...

My initial thinking was along the lines that HDV or HD video looks extremely good when rendered down to DVD format, so perhaps this principle held good for audio.

As well as the piano and tenor voice recordings, I'm also doing piano alone - a separate performance - which the tenor will use for busking - he's a student, with I'm told a fine voice which I haven't yet heard. The mixed CD will be for his portfolio for various uses, including applying for a place at overseas academies.

"The mixed CD will be for his portfolio for various uses, including applying for a place at overseas academies. "

Probably not a bad idea to get some video while you're at it. Some places seem to want to have a look at what they're getting.

When you're mxing remember to check phasing. I was doing a mix some time ago and the bottom end would get lost until I inverted the phase on one channel. Ooops, one mic was out of phase with the other.

Bob.