VU meter: Maybe you should call it 'analogVUemu'. Phase correlator: Yep, some people generally spilt frequencies at around 200, resp. 250 Hz before they add effects or they avoid to panorama deep sounds. A phase correlator can be mistaken, because of some single sounds that don't matter in the sum. I just check my mixes by listening to them in mono, but I agree that some people don't hear phases and they become trouble, because their tapes are forbidden to be played on the air.
I didn't test your plugins and I don't believe in meters and phase correlators. I guess your VU meter is useless, but the phase correlator seems to be useful, the way both are described by you. Explanation: - Bad! Having a VU meter that can be adjusted to allegedly be in sync with some analogue VU meter never ever will be fine. Compare margin for your digital meters and the meters on your mixing console by playing the same song several times, they always will differ a little bit different, each time you play the song. It seems to be dangerous to have such a VU meter, similar to microphones with switches at the handle, a stupid idea that can cause a lot of trouble. - Okay! Broadcasting laws force to stick to limits for phase correlation and referring to your description it will be possible to see it by your phase meter. My 2 cents to the theory of your meters. Cheers, Ralf Fraser wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hi Fons > > Fons Adriaensen wrote: > >> What's the point of using a meter if you adjust it to the signal ? >> > > You are not changing the signal, you are changing the amount of headroom the > VU > meter has. http://www.reference.com/browse/wiki/Headroom > > To put it simply, 0dB on analogue equipment is indicating the optimal level. > There is an amount of headroom above that level before distortion will occur. > > In the digital domain 0dB is the absolute maximum level and distortion occurs > at > this point.. > > So whenever analogue equipment needs to work with digital equipment it is > configured so that 0dB in the analogue domain is at some (hopefully calibrated > and consistent) level below 0dB in the digital domain. The actual value is > arbitrary and depends part on preference and part on the quality of your > analogue gear. So if you elect to have 9dB of headroom on you analogue gear, > then you'd select -9dB on the plugin, and then VU metering 0dB will have the > peak metering -9dB. > - -18 to -9 is common, but I've seen all sorts of things. > > >> Anyway the meter plugin freezes my machine if the signal is muted >> or removed. Probably due to denormals. >> > > I can't reproduce that. > A clue may help. (distro, arch, kernel, soundcard, host etc). > > The plugins have been built on ubuntu studio (hardy) x64 > and tested on ubuntu jaunty (x64), Arch linux (x64) & AV linux (x32). > > >> The VU is not a VU, >> > > Correct since this plugin isn't in the analogue domain. It's a simulant. > It does convey the 'perceived volume' of a signal better than a peak meter and > does help if you are mixing to tape. > > >> the spectrum doesn't use valid 1/3 octave filters by any standard, >> > > please advise where this standard is. > AFAIK there are just algorithms that simulate the behaviour of electronic RC > circuits with varying degrees of success, and yes I have a munge. Sorry if it > disturbs you. > > >> and the phase meter doesn't indicate anything useful. >> > > Apart from the relative phase difference between the left and right channels. > > With the demise of vinyl the importance of phase has been lost too to some > extent so it doesn't surprise me you don't what this meter is for or what it's > trying to tell you. > > On vinyl out of phase signals make the needle go up and down instead of side > to > side, this makes the needle bounce out of the groove. Worse still is what > happens when you have low frequency out of phase sounds. The wave length (on > the > vinyl) is large enough for the cutter to go through the vinyl... => This is > why > everything below 200Hz is mono'd for vinyl during mastering in case you were > wondering. > > A quick guide to interpreting the phase meter: > * A mix that never goes +/- 20 is too mono. Pan something. Create some space > with reverb. etc > * A mix that spends all it's time between +/- 45 is as 'wide' as you want to > get. You should able to see some variety in there of course, ie a verse and a > chorus should be different widths. > * If the phase meter spends any time over +/- 55 then audible cancellation > will > occur if the mix is mono'd or listened to from a distance. > * Any travel over +/- 60 is trouble, there is something out of phase in the > mix. > although this may sound great with your head between the speakers it's going > to > suck when heard anywhere else. > * If the meters stays at +/- 90 then the whole mix is out of phase :) > > regards, > Fraser > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org > > iD8DBQFKkWJ9NZroiEh4erwRAopXAKCd7WvN5FZLUw4upP9dpQb0K8SpjwCeOVAh > KkDpklpsKFIKijiJAEV1PWo= > =U2Yr > -----END PGP SIGNATURE----- > _______________________________________________ > Linux-audio-dev mailing list > [email protected] > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
