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Is my new C414 B-ULS close enough to form a matched pair??

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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby John Willett » Tue May 21, 2019 12:40 pm

Hugh Robjohns wrote:
John Willett wrote:... and so is much more easily overlooked or ignored.

Or not noticed at all, as the resultant left/right pair matrixed out of the MS are perfectly "pair matched". ;) :thumbup:
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Hugh Robjohns » Tue May 21, 2019 12:45 pm

John Willett wrote:...the resultant left/right pair matrixed out of the MS are perfectly "pair matched". ;) :thumbup:

Pair-matched, true, but both with distorted (virtual) polar patterns...

MS doesn't correct the microphone mismatch, it just conceals the problem a bit better...

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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Guitarking » Tue May 21, 2019 2:40 pm

Yeah I've tried MS before. I like it but I also wanted to dive into Blumlein. I hear good stories about it (very natural sound/image), that's why.

Consulted a mic tech. He suspects one of the mics has had a diafragm change (apparently there are several B-ULS diafragms) hence the slight mismatch. If he/I can find another diafragm, it's quite expensive to change, around 300 euro's.

I could just use these 2 mics; I can perfectly record piano/drum overheads with these as an spaced pair right? Or XY in mono? Or as separate tom mics? Then see if another one comes along for a fair price and try that one, selling one of these. Again, I don't think they're broken, just not perfectly matched.
I'm reluctant though to let my first B-ULS go, I really liked it on my voice and for some reason I have in my head that most people prefer the B-ULS with the transformer for some character (and find the XLS too bright/hyped).

I could also sell both and for that money (hopefully) buy a mp of XLS's.

Regarding Blumlein, maybe I should let go of blumlein with the 2 B-ULS and find another mic that can do that? I have TLM102, 2x C1000, SE X1R ribbon, 2 AKG C414 BULS (yeah, the one's!), NT2A, NT55's matched pair, sm57's, MD409. Would buying another NT2A or X1R ribbon be an idea, maybe chances for a matched pair are higher then?

Last question: I keep on talking about Blumlein (as if I know what I'm talking about lol), but is Blumlein a useful technique for me? I'm in a homestudio or recording piano in my living room most of the time, although I tend to record elsewhere more and more often. I'm not in the position nor do I have the skillset to receive critical paying clients (hopefully yet) but working hard to invest in knowledge and skillset to hopefully one day be able to do so.

Thanks so much for all the help, very education and appreciated!!
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Hugh Robjohns » Tue May 21, 2019 3:16 pm

Guitarking wrote:I also wanted to dive into Blumlein. I hear good stories about it (very natural sound/image), that's why.

;-) You'll probably find as many disparaging comments about it as positive ones -- as you will for any mic technique. It is a classic coincident array, so the imaging is clinically precise (with well-matched mics 8-) ), but it inherently lacks the kind of 'spaciousness' that is associated with spaced arrays like ORTF or AB. Horses and courses...

The Blumlein array has a particular set of qualities that can be useful and effective in certain applications, and wholly inappropriate in others. The rear pickup lobes can be highly problematic in poor-sounding rooms, as can the out-of phase side pickup zones, while the relatively narrow stereo acceptance angle requires a more distant placement than some alternative arrays which imposes a more open perspective which is, again, highly room dependent.

So yes, in the right situation the Blumlein array can be a wonderful sounding thing. In others it just doesn't deliver anything useful.

Consulted a mic tech. He suspects one of the mics has had a diafragm change

Replaced diaphragm or capsule does seem a strong possibility...

If he/I can find another diafragm, it's quite expensive to change, around 300 euro's.

That's a lot of cash to pile on top of the cost of the second mic, and there's still no guarantee of precise matching. And which mic's diaphragm/capsule would you change anyway? How do you know that your original mic isn't out-of-spec dull rather than the new one being out-of-spec bright? ;)

All things considered, if precise XY recording techniques are that important to you, I think I'd flog one or both B-ULS mics separately, and buy a matched pair of C414-XLS mics or some other decent brand of multi-pattern mic. The se4400 would be a reasonable alternative at about half the price.

Regarding Blumlein, maybe I should let go of blumlein with the 2 B-ULS and find another mic that can do that?

The Blumlein array requires two mics with fig-8 polar patterns, so you'd have to invest in another mic whatever you decide to do!

Last question: I keep on talking about Blumlein (as if I know what I'm talking about lol), but is Blumlein a useful technique for me? I'm in a homestudio or recording piano in my living room most of the time...

See my comments above. The sound of the room will be the most critical factor in deciding whether the technique is appropriate for your situation. Having said that, I wouldn't personally choose to record a piano with the Blumlein array given other options. I'd be far more likely to choose spaced AB omnis or maybe ORTF for classical pieces, and probably use closer internal mics for more percussive pop-oriented stuff.

But experimentation is the key to learning and gaining experience, so I'd certainly encourage you to try out all manner of different stereo arrays to form an impression of what each offers in terms of strengths and weaknesses. That's where (matched) multi-pattern mics become so versatile and useful, as it's a matter of moments to compare XY cardioids, hyper-cardioids and fig-8s, or AB omnis or fig-8s, or ORTF versus NOS versus DIN ... and so on.

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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Guitarking » Tue May 21, 2019 7:09 pm

Thanks again Hugh.

Do you think, considering the good QC of AKG in 80's-90's, changes are favourable that I could find a B-ULS that matches better? In other words, I'm just having bad luck here? Or are most of the capsules replaced already?

I've tried to test the differences between the two mics by putting them next to each other in front of one of my Dynaudio BM6A speakers while recording a burst of white noise. I analysed with SPAN. Ive included a screenshot. Any comments/conclusions to draw from that? Left is latest C414 right is the one I already had.

Image

Mmm seems like blumlein might not be right for me most of the time as I'm in my homestudio or living room...

Interesting that SE 4400. How does it compare to CAD 179? Or an Audio Technica equivalent?

Are C414 B ULS ease to sell for a good price?
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby innerchord » Tue May 21, 2019 7:52 pm

Assuming identical mic placement, I would expect to hear the noticable difference in the treble between those two mics. One might need servicing, although the flatter plot is from the old mic, I see. There are many other factors, of course. I'd want to compare another new 414. If that's a better match, sell the old one? (Unless it sounds better than both new ones!)
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby John Willett » Tue May 21, 2019 8:50 pm

Guitarking wrote:Yeah I've tried MS before. I like it but I also wanted to dive into Blumlein. I hear good stories about it (very natural sound/image), that's why.

Two fig-8 mics in MS *ARE* Blumlein. :thumbup:
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Guitarking » Tue May 21, 2019 9:06 pm

Mind you, they are both old mics. With old and new I mean the one I bought a few years ago and with new I mean the one I bought last week.

About 2 fig8 mics are blumlein, isn't there a difference in how you put them relative to the source, I mean xy has the middle of the source of axis while MS has the source on axis in one of the mics namely the mid mic?
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Hugh Robjohns » Tue May 21, 2019 11:05 pm

Guitarking wrote:About 2 fig8 mics are blumlein, isn't there a difference in how you put them relative to the source, I mean xy has the middle of the source of axis while MS has the source on axis in one of the mics namely the mid mic?

Yes, the classic 'Blumlein array' is an XY array with two (matched) fig-8s with a mutual angle of 90 degrees (although it's often used at 80 degrees in practice for a slightly wider stereo recording angle), with each mic aimed 45 degrees left/right of the centre of the sound stage. So a central source is off-axis to both mics.

However, Blumlein also developed the concept of Mid-Sides arrays, also using mostly fig-8 pattern mics. So in an MS array the Sides mic is always a fig-8 (with the positive lobe facing stage-left), and the Mid mic (which can have any desired polar pattern) faces the centre stage, so a central source would be fully on-axis to the Mid mic.

A Mid-Sides array of fig-8s translates precisely to an XY array of fig-8s, and vice versa.
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Guitarking » Wed May 22, 2019 5:36 am

A Mid-Sides array of fig-8s translates precisely to an XY array of fig-8s, and vice versa.

Are you saying you can get the Blumlein sound (XY fig8 centre off axis) with MS using 2 fig 8 (XY fig8 one mid mic on axis, decode)??? So same sound but with two slightly different setups?
Which means I can get the Blumlein sound without the precisely matched mics (I know, technically there's still distortion but less obvious), namely by using 2 fig8 MS and decode them? If that's true I think I now understand why some suggested going MS.
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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby Hugh Robjohns » Wed May 22, 2019 9:27 am

Guitarking wrote:Are you saying you can get the Blumlein sound (XY fig8 centre off axis) with MS using 2 fig 8 (XY fig8 one mid mic on axis, decode)??? So same sound but with two slightly different setups?

Assuming you get the MS decode matrix values right, the stereo imaging is the same, yes.

Which means I can get the Blumlein sound without the precisely matched mics...

No, you can't. As I said before, there's no free pardon for unmatched mics!

However, instead of lopsided image shifts, you'd end up with frequency-variable image widths which may well be less noticeable. But the imaging still won't be as precise as it should be, which makes it a bit moot since the whole point of the Blumlein array is fantastically precise imaging... ;)

But as I've also been saying all along... try it and experiment for yourself. It's the only way to learn the effects of mismatching and to decide whether they are significant to whatever you're trying to achieve.

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Re: Is my new C414 B-ULS close enough to form a matched pair??

Postby CS70 » Wed May 22, 2019 12:03 pm

Hugh Robjohns wrote:
Watchmaker wrote:I....very, very few people are going to listen to a recording and say "by jove! they shouldn't have used the xls on that...the B-ULS is much better for that sort of thing"

I bet they would over at 'the other place' ! :lol: :bouncy:

But that's only after u tell 'em what you've used.. :D
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