Matched Pairs... Necessary or Expendable???

J

jesse89

New member
I've heard a little bit of info about matched pairs (of condenser mics), and I am currently under the impression they are only worth while when recording stereo, i.e. on drum overheads... I wonder if the same quality could be achieved with two decent quality unmatched mics, such as a pair of MXL 2003's. So I was hoping someone could shed some light on the issue... are they necessary, or just a waste of time and money??
 
In a spaced pair application where the two channels will be mixed to taste, say close-miced acoustic guitar, it is not important. On spaced pair drum overheads, it is debatable. For coincident pairs, especially in critical recordings, it is more important.

The next question is how closely matched are two random mics from a particular manufacturer? If the only meaningful difference is sensitivity, then you can self-match by noting which mic is hotter and adjusting at the preamp or in mixing. But if the frequency response is dramatically different, it won't make a very satisfying stereo image.
 
this man knows his stuff. i have inexpensive "matched" overheads, small diaphragm condensers and one has a slightly higher output, we have tried them through 4 different mixers and the result is always the same, so now were forced to turn it up a bit more because it can't handle as much SPL as the other so the noise is higher cause the gain stage is forced to be lower, and that is no fun, do the homework, i have cads, i wish i at least had MXL's...:o
 
I think the better the company the closer the mics will be from any given pair...Ive got 2 MXL 603s and when generating pink noise and looking at the output on a program with a spectrum analyser...they seem fairly close...but they were picked at random.

but how do we measure this most of the time...with our ears?...If you cant tell a difference with your ears...they should be good enough to go.
 
Some companies like Neumann and Audio Techinca don't sell specially matched pairs as they claim that their manufacturing tolerances are so close that any two of the same model mic will be sufficiently matched.
 
I concur...I wonder if the AT being that good has to do with them being Japanese...Id think that AKG and Shure should be able to make that claim too.
 
I think if they're close--like say one is brown, and the other's black--and your pants are long enough, no one's likely to notice anyway.

Wait a minute...

We're not talking about socks, are we? :confused:
 
Unmatched pairs are annoying. The gain knobs sit at different spots, the noise floor differs, the proximity effect is different, and sometimes the frequency response differs too. With those conditions, it's near impossible to make them sound right as a stereo pair.

Matched pairs are more forgiving. Set and forget it. Adjust the gain the same and all is good. No trial and error and monitoring to no end to ensure you got it close enough. Just use to taste.

Not that big of a deal if you don't use them as a stereo pair. But as a stereo pair, you're drastically increasing your workload in post to make an unmatched pair sound matched(if that's even possible). Not that most people will notice much. But if you are one that will, it will drive you batty why they don't sound matched / right. Even if they're good mics of the same make and model and should be matched by all other accounts.
 
---concurs---

yeah -- with an unmatched pair that have different frequency responses in the ranges you care about, you'll be constantly messing with left and right panning, trying to get the mix to sound balanced, and then if you finally do, and later apply some eq, it'll probably be off again! argh!

But -- I have some pairs that are not matched, but the main difference seems to be in the very low frequencies (like, one has good response and one doesn't) - and since I'm usually using them for acoustic instruments where I pretty much plan to EQ away the very low frequencies anyway, they're workable. I don't know if that's a likelier place (the low frequencies) to see a matching problem than elsewhere, but if so, then the happy coincidence I'm talking about could work to lessen the concern with lack of matching overall.
 
The above two posts are 100% possible, realistic potential problems. In my own experience I've never had a situation where an unmatched pair was far enough off to cause any problems at all. Like Pohaku said, AT doesn't even match anymore for that very reason.

Frank
 
here's another related question:

suppose i have a "matched pair" of condensers and, when not recording in stereo, use one of the two to record, say for instance, vocals or guitar. will the process of me using one more frequently/heavily than the other degrade the sound of that one mic at a faster rate, thereby making them no longer matched?
 
fat_fleet said:
suppose i have a "matched pair" of condensers and, when not recording in stereo, use one of the two to record, say for instance, vocals or guitar. will the process of me using one more frequently/heavily than the other degrade the sound of that one mic at a faster rate, thereby making them no longer matched?
Click to expand...
Nah - maybe over decades? The electronic components would be aging simultaneously, of course, and most of the degradation issues I'm familiar with happen whether the components are in use or not. If you somehow managed to damage the one in use, that's another story, of course.

(note: antichef has just stepped fully outside the scope of his experience with this post, having only possessed most of his condensers for a few years)
 
The capsule itself is a more likely cause of drift over time, and it is mostly subject to environmental conditions. No guarantees, but if you store them properly and together, that's your best bet for keeping them matched.
 
Even matched pairs can become unmatched. Granted that factory fresh and less than six months old, not likely by most accounts.

Manufacturing tolerances don't take aging, use, and damage into account. I had two SM81's, less than 20 apart in the serial numbers and they were NOT matched. Even though they were basically mint in appearance. Close to a 5dB difference between the two mics. More so in proximity. That and being very directional made them useless as a stereo pair. Stereo micing a single instrument, great. Stereo micing an ensemble, not so much. So it really depends on how you intend to use a stereo pair. And which pair.

I live in Texas and my mics bake in my car for several hours every time I take them out of the house. Plus exposure to the elements and directional sounds that might affect the mics over the long haul. I guess that's one advantage to being a weekend warrior only. One year of abuse is basically five years of use.
 
stereo image

Hi,

I am not a matched pair purist. I often use completely different mics in stereo recordings with good results.

However.

If you are recording a room full of music with a stereo pair and you get a good stereo image you should be able to place the musicians in the image.

Say it's a string quartet. You should be able to close your eyes and hear where the cellist sat. Even point your finger at her.

If the pair is unmatched frequency wise the position of the cellist may drift depending on the notes she's playing. So when she's playing a lower part you point your finger here. And when she's playing a higher part you point your finger there.

This is obviously not desirable.

Thanks,

Hairy Larry
 
That's the gist of it Jesse. Necessary? No. Expendable? No. Desirable? Yes. Simply reduces the pain in the ass factor. Also, note that "matched" is debatable concept. Even the finest matched pairs are not absolutely identical across the audio spectrum, so we have to agree on acceptable tolerances. I would say that within 2 db across the audio spectrum is usable. I would call 1db or less "matched". Less than 0.5db, and my ears couldn't tell the difference. Beyond that, and I think you are into diminishing returns, wasting money for sonic wanking. Sometimes you just get lucky. I have a pair of Oktava MC012's I bought at GC for $50 each that are as well matched as the set I bought from the Sound Room, which were carefully matched. I sold the Sound Room mics, because they were worth more money (and cost more money), and kept the lucky matched pair. What the hell? The caps for those 2 mics must have come out of the same obsolete Soviet tank.-Richie
 
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