It sounds awesome, unless it doesn't! How is the perceived pitch of my recording changing on different sound systems?

August 15, 2012 6:32 PM

My recording sounds fine on some sound systems, but occasionally seems off-pitch on other setups. I have no idea what's going on. Help me understand this, and prevent it in future?

I wrote & recorded the music for a wedding I'm attending this weekend, and I'm quite proud of it, so I've been playing it for various friends as we visit them. I'm baffled and a bit horrified by something that's been happening.

The piece sounds just fine on some audio setups - from laptop speakers and my iPhone to my monitor headphones and fairly high-level sound systems - but on other sound systems it sounds like my vocals are slightly off-pitch in a couple of places. The pitch issues, if they're there, are in specific places that are consistent each time (including one in the opening line, ack!), so there is some pattern to this. They're slight enough that most listeners apparently couldn't hear them, but I certainly can, and expect other musicians would as well.

I'm an experienced performer and session vocalist, so naturally I checked the pitch on all the vocal tracks as I recorded them. They sounded fine on my monitor headphones and the various devices I played it back on before finalising the piece.

From playing around on my audiophile partner's fancy amp, it seemed like the more processing the amp did, the more likely the pitch issues were to show: it sounded fine in "Pure Audio" mode, but worse as I moved into the PLIIx, THX and Neo:6 modes (not necessarily in that order). But I don't understand what's going on here - I'm a classical musician who's still learning electronic music-making, and very new to mixing & production, so I'm wondering what I've done to create this oddly inconsistent effect?

Of course, now I'm paranoid that the sound system at the venue is of the sort that makes my voice sound off-key. My recording gear is at home and I'm not, so I can't really do much about this before the wedding! I'm also concerned that this could be an issue with other things I've recorded - I cringe to think that some of the music I've been sending into the world might actually play as off to some people.

Please give me your thoughts, and any reassurance you can offer?

I'm afraid I'm unlikely to understand high-level audio-engineering jargon; this really isn't my field (yet). Still, I'm hoping someone can shed light on this strange situation - the better to avoid it in future!

posted by Someone Else's Story to media & arts (7 answers total)

MP3?
posted by roboton666 at 6:49 PM on August 15, 2012

The reason I ask is that MP3 compression and bit rates have caused funky differences on the tempo my iPod plays as compared to a WAV of the same recording burned to a CD.
posted by roboton666 at 6:51 PM on August 15, 2012

They sounded fine on my monitor headphones...

First off, are you mixing your material via headphones? Because that's a pretty serious no-go if you really care about quality consistency across all sound systems -- there's a reason people invest thousands in studio monitors and soundproofing rooms. (And I'm not saying that you need such monitors; you might just want to adjust your current expectations accordingly.)

From playing around on my audiophile partner's fancy amp...

Are you talking about a pre-amp that you use while you're recording? Or is this something you're doing post production?

And yeah, always record at a minimum 44.1 kHz WAV.
posted by lobbyist at 6:52 PM on August 15, 2012 [2 favorites]

Is the bass out of tune and you can only hear it on certain systems?
posted by bongo_x at 9:55 PM on August 15, 2012 [1 favorite]

MP3 (192k), WAV and AIFF. This is an interesting point - I haven't kept detailed notes of which format I played where, since I've been on the road. But I can say with confidence that the quirky pitch effects have been by turns present and absent when playing the same MP3 file on different sound setups. I've plugged the iPhone into a couple of different systems at people's houses, as well as playing the song on the phone's speakers, and the pitch issues aren't consistent when playing the file.

It's good to know that MP3 compression can cause tempo trouble, though I'm bemused as to how the same file can sound different pitch-wise - I'd have thought that it was either in tune or not in tune? And what are we supposed to do with that knowledge, when MP3 audio is pretty much the standard at the moment?

lobbyist, I've done a fair bit of reading on the monitors+tuned-room vs headphones debate for mixing, and made the best choice for my situation (rank amateur, no dedicated studio space, tight budget, etc). I've been trying to compensate for the limitations of my setup by playing back my pieces on as many different sound systems as possible; this is the first time I've ever encountered something like this.

The amp I mentioned is one of those playback options - it's not a piece of recording equipment, but part of my partner's music/home theater system. (It's interesting hearing my stuff in 9-channel surround sound!)

I don't think my expectations are that unreasonable - I'm not expecting perfection from my little home setup, nor do I believe I'll master these skills overnight. But I am expecting things to be in tune when they sound like they're in tune, or to not be in tune when they're not, which seems reasonable to me? The idea that that might vary according to what you're listening to the piece on seems very strange to me. And it's not an issue I've even been able to find any information on.

I'm recording at 96KHz or 192KHz, thanks.

bongo_x, the bass is fine - it's all software instruments anyway. It's just those 2-3 spots in the vocal track, on some sound systems and not others...
posted by Someone Else's Story at 10:36 PM on August 15, 2012

Well, this seems really odd at first read - sound systems don't alter the pitch of only certain elements only at certain times. So the first thing I thought was that your recording set-up and other systems you've played it on just aren't good enough for you to hear when you're slightly off pitch - when you play it on better gear, everything is clearer, and your slight inaccuracies become more noticeable. And that still could be the case.

But . . . .

Home Audio/Visual stuff isn't something I'm super familiar with, so I did some Googling of "PLIIx", "THX" and "Neo:6" and . . . hmmmmm . . . . "the more processing the amp did" may not be crazy-talk.

PLIIx & Neo:6 are two methods by which a stereo (2 channel) signal is "converted" into "surround sound"; 5 or 6 different channels of audio. I strongly suspect they do this via manipulation of various frequencies and phasing and delays and digital reverbs and maybe even some very slight pitch-shifting. So your poor little ordinary stereo recording is being put through the wringer in order to attempt to squeeze a "movie listening" experience out of it, and I could definitely see that as the sound is sent back out into the idiosyncratic acoustics of the room you're listening in, the combination of the "surround sound" manipulation and the acoustics is making things seem out of tune. I could especially see this being true if you're using these settings, but still only listening in stereo.

When I read in the audio engineering trade mags about albums being released in a surround sound version, they're always talking about doing some really extensive remixing and/or remastering on hundreds of thousands of dollars worth of equipment, in order to make sure that it sounds right when played on a surround sound system.

THX is . . . . I don't really know what. It's a set of standards for movie theaters (including structural elements & acoustic treatments), and THX-certified home gear can be used in a home installation where somebody spends the bucks to build a dedicated THX-certified home theater, but what happens when a "THX" button is pressed on your partner's receiver is anybody's guess. So there could be some ugly stuff going on there, too.

So mostly, I think you can relax a bit. Listening to your recording on various systems is still a great practice, but maybe stick with "Pure Audio" or plain-ol'-ordinary-left-and-right stereo systems. You don't have a surround sound recording, avoid the surround sound settings.

And I'd really relax when it comes to the wedding. Wedding venues tend WAY more towards the "lo-fi" than the "hi-fi" - you should count yourself lucky if you and everybody else don't wind up sounding like Charlie Brown's teacher ("wonh wah, wonh wonh wah wonh-wonh-waaaah.") And even if they sprang for a band or a DJ with good gear, "loud" is probably more likely than "super hi-fi."

And if you REALLY want to make sure your music sounds good on almost any system, see what it sounds like when you sum it down to mono (combine the two stereo channels into a single channel). Totally not kidding, here - a lot more stuff than you might think is mono either intentionally or accidentally.
posted by soundguy99 at 11:15 PM on August 15, 2012

There may be a timbre to your voice at those points that the processors on the amplifiers are mistaking as a fundamental and equalizing up instead of down. Or a phase issue that confuses the processor.

Sort of like how sometimes when people are talking on the phone a touch-tone beep comes out. That's because there's a processor somewhere along the path listening for sounds that sound like touchtone and inserting clean ones in their places. That's probably what is happening- these processors are hearing something that's close to something they are trained to "fix" and are accidentally messing up your sound.

Soundguy99 is right. When you play it back, just make sure processing is turned off. And he's also right about turning it into mono. The processors use the differences in the stereo tracks to do their magic, and if it is just your voice on the track there isn't any useful stereo information there anyway. And in a hall, stereo just means half your audience is missing part of your recording. The further away from the ears the speakers are, the less beneficial stereo is going to be.

It could also be the iPhone. These things are meant for passive, personal listening. They are allowed to make mistakes in reproduction, and they are equalized to sound good in their earbuds.

Your best option for reproducibility is to use a lossless file format like WAV or FLAC or Apple's lossless format, and make it mono. (Two identical tracks.) If you have to use the iPhone, make sure to test it's internal processing. But you should use a CD.
posted by gjc at 7:20 AM on August 16, 2012