Do you Invert Polarity in recording of guitar?

[rick-slo]

Originally Posted by Doug Young

mic's going to be very much in phase already. With 2 mics, I would not play games with processing to change the phase (unless you were trying to rescue someone's bad recording, or want some unusual effect). You choose your mic placement according to the sound you want. Co-incident setups like XY should not have any significant phase differences anyway. For spaced pairs, phase differences are part of what makes the stereo sound, so you wouldn't want to alter that (I wouldn't anyway). If you think you have too much phase differences in a spaced pair recording, I'd move the mics, maybe closer together, less spaced out. Basically just use mic placement to get the sound you want.

Post recording something you can explore small R or L track delays which change the phase relationship between the right and left tracks. No reason not to explore and pick something you like. Say I would like a little more solid sound around 494 hertz for a melody note, I could explore. Also going for mikes being equal distance from the guitar (and what parts of the guitar by the way?) is limiting in options. Bing able to tweak a channel delay neutralizes much the usually given reasons for that practice. Delay tweaking is most directly useful when listening with headphones rather than with speakers (where your head may move around and where there are sound reflections from the room boundaries back to your ears).

[Doug Young]

Getting a bit far away from "do you need to invert polarity" :-), but as you can see, Victor, there are lots of ways to do things. As long as they sound good, they're good. I prefer to get things right going in, rather than having to do corrections later. Mic placement is quite powerful. But you can also do things in the mix. On some of my you tube videos, I made keeping the mics out of view the priority, so the mic placement wasn't optimal, and then I'd do more to try to adjust afterwards. But when recording just audio, I try to dial in the sound I want right up front. But that's just one way to do it! Rick makes nice sounding recordings with his approach.

[rick-slo]

Originally Posted by Doug Young

Getting a bit far away from "do you need to invert polarity" :-), but as you can see, Victor, there are lots of ways to do things. As long as they sound good, they're good. I prefer to get things right going in, rather than having to do corrections later. Mic placement is quite powerful. But you can also do things in the mix. On some of my you tube videos, I made keeping the mics out of view the priority, so the mic placement wasn't optimal, and then I'd do more to try to adjust afterwards. But when recording just audio, I try to dial in the sound I want right up front. But that's just one way to do it! Rick makes nice sounding recordings with his approach.

"Do you need to invert polarity" was a one word answer.

Always try for the best recording from the get go. Saves time in the long run. Biggest thing post recording for me is choosing which reverb and using a bit of equalization if needed.

[Bob Womack]

Originally Posted by Knives&Guitars

*Do you believe that the individual higher quality Phantom power supplies gives better Audio Transparency? Are the newer-cheaper phantom powers as good as the old?

The way phantom is done, the power legs cancel each other out. As designed, it should be really hard to screw it up. The legs of power use phase to cancel themselves out in the signal.

* And what role did the Transformer coupled Phantom power play in the recording chain? Was the transformer there for transformerless boards?

I think the only reason there was a transformer in the circuit was because they envisioned this box being use on location and the possibility that someone might use a "Y" cord to put the two mics into a single tape machine input. The transformers were to isolate the mics from each other to prevent loading in case of a short.


Bob

[Brent Hahn]

My possibly flawed understanding is this: Audio is AC while phantom is DC. AC will cross a transformer but DC won't. The transformer allows phantom power to reach the mic's internal preamp while keeping it away from all the other circuitry downstream.

[Bob Womack]

Originally Posted by Brent Hahn

My possibly flawed understanding is this: Audio is AC while phantom is DC. AC will cross a transformer but DC won't. The transformer allows phantom power to reach the mic's internal preamp while keeping it away from all the other circuitry downstream.

That's also a possibility.

Bob

[jim1960]

Originally Posted by Knives&Guitars

Could not the quality of a Phantom Power supply effect some sort of sound difference in a mic?

This came up recently in one of the threads here. 500 series power supplies were an issue in some cases a decade back when folks were just starting to get into these units. It's been a lot of years since I've seen anyone complaining about any 500 series power supply so I think those issues are in the past. My CAPI chassis is powered by their VPR Switch Mode VPU. They used to sell a bigger PSU that sold for three or four times the price, but when I was inquiring about what PSU to buy, I couldn't find anyone who warned me off of the smaller one. So far, it's done the job well.

[Brent Hahn]

Originally Posted by jim1960

This came up recently in one of the threads here. 500 series power supplies were an issue...

Right, but the issues seemed to be with the general-purpose 16v rails and the grounding, not the 48v rail (which many 500-series units don't use anyway).

[jim1960]

Originally Posted by Brent Hahn

Right, but the issues seemed to be with the general-purpose 16v rails and the grounding, not the 48v rail (which many 500-series units don't use anyway).

Have you come across complaints on that front? I've seen nothing on any of the audio forums where I participate (that includes the period last year when I was researching what chassis to purchase). If I missed something, I'm curious as to what it is.

[Brent Hahn]

Originally Posted by jim1960

Have you come across complaints on that front?

Used to see them but the surviving manufacturers seem to have sorted it out. I'd probably still re-investigate, though, if I was planning on, say, getting a 12-slot box and filling it with tube modules that draw a lot of current. Phantom seems to be a non-issue though.

[jim1960]

Originally Posted by Brent Hahn

Used to see them but the surviving manufacturers seem to have sorted it out. I'd probably still re-investigate, though, if I was planning on, say, getting a 12-slot box and filling it with tube modules that draw a lot of current. Phantom seems to be a non-issue though.

For what it's worth, before I bought my CAPI chassis, I spent two or three months reading everything I could find on the various contenders because of what I knew to be true ten years ago. Parts and build quality seemed to be the only things that differentiated the choices and I didn't notice any clear consensus that would put a particular brand on the top of the pile.