I don’t know if this forum is the most appropriate to ask this questions but since Ardour got me into mixing and this community seems nice I’ll give it a shot.
Recently I acquired a pair of Mackie CR-X studio monitors to get a more faithful mix. I came across something strange when I started experimenting with them.
Even though my room acoustics is far from ideal, is it normal for the monitors to sound slightly off centered?
I mean, I didn’t actually measured the distance between each of the monitors and myself, but I thought that the difference shouldn’t be so noticeable.
I use Cadence to connect my Linux system to the audio interface. What I’m doing is manually trying to center my monitors using the balance in my system’s sound output.
Do any of the more experienced users year has any thoughts on this? I would like to learn. I should note that I’m not trying to build an ideal studio, just trying to figure out if the equipment might be faulty or not?
General rule number one is that you and the speakers should form a perfect triangle. If the speakers have different distances from you, then you will get phase issues. But if the distances are alright, then you can balance with faders/pan/volume controls(s). It’s also a good idea to mix in a sound level where it’s possible to hear or speak a normal conversation, that way the room has lesser impact and if it sounds great on low levels, then it will normally sound great on other levels as well.
If it’s not a placement problem, then it’s probably the mixer, soundcard, or your ears.
When I need to be picky about panning I set up monitors with a tape measure (or marked length of string) and protractor. In some cases you can hear path differences of a few cm as a (small) shift in position.
You of course need to also make sure that the electrical level of left and right channels match very closely, and if you have amplifiers or active monitors with gain controls that the gain from input to speaker output is matched very closely. That is the biggest hassle on my desktop audio system, my audio interface has small knobs to set output level, and my speakers also have small knobs to set gain, so it is physically inconvenient to make fine adjustments.
Indeed I should be being a little too picky. But I think I’ll try measuring the position of each monitor to be sure. I didn’t do it straight away because I wanted to dive right into the mix.
There’s many elements that can influence the perception of the sound coming from your monitors like proximity of other surfaces if they have a rear bass-reflex port and the room’s accoustic obviously
You can find many tutorials on the web explaining how to properly calibrate your monitors, including placement and adjusting their individual volume by running pink noise through the system and measuring the Sound Pressure Level.
When I setup my monitors, I bought a used SPL meter (dbC), that was rather inexpensive and it was overall a quick process.
We have noise generator plugins in Ardour so that’s really all you need
Thank you very much @timetre. I’m sorry if this is a trivial matter but I like to get information from actual people, because experience sometime is different from what I read in books or in the internet.
I’ll check that video and try to calibrate my monitors. I thought that one could get a good monitor setup right off the bat, but I guess that given the various factors that can affect the way the sound reaches me from the two monitors and even my audition itself, I guess one has always to adjust to a particular situation. I was just worried that the monitors might be faulty, but given all the factors checking this might become obsessive. I just want to make some music.
Sorry, but I’m going to start off with a bunch more fundamental troubleshooting questions (like the ones they ask you at tech support when you’ve been on hold for an hour):
1.) when you say you “acquired a pair of Mackie CR-X studio monitors”, I trust it they were new/refurbished from a reputable dealer, not bought off the back of a truck in a sketchy part of town.
2.) and second only to the “turn it off and turn it back on again” method of troubleshooting, have you tried switching the positions of each monitor? In other words swapping left and right (and fiddle with the L/R switch on the back). (personally I debugged a shoddy woofer connection on a pair of bookshelf speakers that way).
3.) Is the “off center” sound tilted to the active or passive speaker side? And I don’t know if it makes a difference, but how’s the quality of the speaker cable connecting the two?
4.) What kind of interface are you using and how is it connected (balanced TRS, unbalanced TS, one of each )?
5.) And finally, totally grabbing at straws, does your interface have an internal software-controlled mixer that may have been tweaked and forgotten?
1.) Yes I’ve bought them from a reputable dealer. There are brand new.
2.) I tried this when you mentioned it. I had the powered on the right and when I switch it it remained similar. Remarkably the sound always sounds tilted to the left. I guess it is the acoustics or my ears .
3.) I calculated that the powered speakers is always less that 1db quieter than the passive one. But that should be just a minor error right?
4.5.)My interface is somewhat old and I’m using unbalanced jack-RCA connectors which probably are the reason of a quiet hum on the monitors.
This goes to show that acoustics is really a big deal. And yes, I bought the lowest price Mackie monitors so I shouldn’t expect a very high fidelity. They say studio-quality but after this discussion, I guess if they were studio quality they’d have a separate gain in each speaker to solve this kind of issues . I think I’ll use the pan in the output to center the output so that final mix is also centered and when I have time to set a proper studio I’ll take all your suggestions into consideration.
This article from DPA Microphones may be of use. Figure 6 has perceived angular shift as a function of level and time difference. Stereo recording techniques
A 2dB difference with no time difference is perceived as around a 10 degree shift, but a 1dB difference with a 0.15 ms time delay is also perceived as around a 10 degree shift, or no level difference with around 0.2ms time delay is also perceived as around 10 degree image shift.
Sound propagation is approximately 1ms per 0.3m, or 1ms per foot, so 0.2ms is only around 0.06m, 6cm. So if one speaker is a few cm farther away you may notice that, depending on how big the off center effect you are noticing.
Close surfaces can also reflect sound back, and make the level seem slightly higher if one side has a large surface (e.g. wall) very near and the other does not. Symmetrical room setup is better if it can be achieved.
I doubt it’s the same thing but I had a similar experience where the stereo field was shifted right; but only when using JACK and not with ALSA.
Turned out my Pipewire settings for some reason had the left speaker set at only 30%
pw-cli e <audio interface ID> Props
showed the “channelVolumes” mismatch and pw-cli s <audio interface ID> Props '{channelVolumes = [ 1.0 1.0 ]}'
rectified it.
@finite_time: Please don’t be too optimistic about the Mackies:
In Stereo Speakers there are generally component tolerances of +/- 10% … +/- 20% in the components (mainly capacitors) used in the electronics (Filter, EQ, Amplifier) of these parts. I did not find lower tolerances than 5% in resistors and 20% in capacitors in any amplifier I have torn apart and I did never find a Stereo amp with EQ calibration either - in an afordable price range ;-). The tolerances can even sum up to much more.
And this kinds of speakers can differ easily more than +/- 3dB in sound pressure even in the same production lot… and I do not need to tell you what a 6dB difference means.
There is one inherent difference between left and right speaker : The main speaker which contains the Amp + Power supply has a completely different acoustic performance as the internal free air volume is much less than the passive speaker. This generates a different frequency response. But they use the same speaker, same material, same damping, same geometry…BS
I can observe the same thing on by Behringer MS16 (which are still worse -because smaller- than the Mackies…)
Yes, you are right about acoustics. Mainly if your studio is not an anechoic chamber or veery big.
I would suggest to listen always over an Ardour monitor channel instead of the master channel and kind of calibrate this monitor channel by the in-built noise generator + a test microphone. This should do better than panning… and you will not forget to re-pan for recording
You could even use two presets for the monitor (one for phones one for speaker) and set it to the listening mode you are using.
Regards
Michael
PD.: Most of these smaller speaker work better with the “bass resonance tube” closed or filled by a high density foam…these holes are more cosmetics than real efficient. Just try it.
That seems a very good analysis on your part and your final suggestion is the more straight-forward solution to my problem. This is maybe a trivial question but how do you pan the monitor section? There is no stereo panner like in other stereo tracks. I tried searching for a plugin that would just pan but I can’t find one.
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