question about pickups and phase
- Thread starter antichef
- Start date
ashcat_lt
Well-known member
Yeah, that looks pretty definitive. I'd still want to check the MP with the face-to-face attraction test, but I think the question is answered.
Like I said above - any time you're sensing the string at two different points along the string you will have a difference in phase between the two for all harmonics except the fundamental. Some will cancel more or less, some will reinforce more or less, but it's almost random and completely dependent on fretting. I haven't listened to your sample. If it's really objectionable then you're only real option is to not use the middle setting of the switch. I tend to use N+B more often than either alone, but i know a lot of folks that can't. You might try adjusting the height of one or both pickups to see if you can get a better blend.
Note also that most guitars (yours included) are wired so that the pickups are combined in parallel. This will always be brighter - with almost a full octave more treble - than either pickup on its own because the total inductance of the circuit is reduced this way.
Like I said above - any time you're sensing the string at two different points along the string you will have a difference in phase between the two for all harmonics except the fundamental. Some will cancel more or less, some will reinforce more or less, but it's almost random and completely dependent on fretting. I haven't listened to your sample. If it's really objectionable then you're only real option is to not use the middle setting of the switch. I tend to use N+B more often than either alone, but i know a lot of folks that can't. You might try adjusting the height of one or both pickups to see if you can get a better blend.
Note also that most guitars (yours included) are wired so that the pickups are combined in parallel. This will always be brighter - with almost a full octave more treble - than either pickup on its own because the total inductance of the circuit is reduced this way.
antichef
pornk rock
thanks man - I'll play with the pickup height, and the next time I have them out, I'll verify that I really have the neck and bridge models, instead of two of the neck or two of the bridge.
On the bright side, through certain amps and effects, the N+B position sounds good now.
On the bright side, through certain amps and effects, the N+B position sounds good now.
I don't know the answer to any of your questions, but to me, in that clip you posted, I don't think the combined pickup position sounds bad at all. It sounds like just about every single coil neck+bridge config I've ever heard. My Hallmark 60 Custom with single coils in the neck and bridge sounds similar when combined. I also have a Strat that has been modded to allow any pickup combo and it sounds like that too with just the neck and bridge on.
heatmiser
mr. green christmas
Yeah, I think all 3 sound more similar in fullness to me than you describe. I think they all sound really pretty good.
I have an SG with 2 P90's and this thread has reminded me that I have issues when combining both PUs, but I guess I'll start a new thread with that issue so as not to hijack this one.
I have an SG with 2 P90's and this thread has reminded me that I have issues when combining both PUs, but I guess I'll start a new thread with that issue so as not to hijack this one.
I've got an Epi SG that I've been wanting to convert to a P-94. I think your clip sold me on the idea.
antichef
pornk rock
I do really like'em - take the plunge
I do really like'em - take the plunge
I think I will. At least for the bridge. That's the only pickup I use anyway.
Lt. Bob
Spread the Daf!
not at all, (I replied to your other thread but I'll add to this one too) ... when you use both pickups together it's like using two mics on a speaker or acoustic guitar ..... they are not gonna be in phase and so you get phase cancellations ...... phase cancellations means some sound is getting cancelled (duh) and so you have less sound and usually a thinner sound becuae lower freqs are more sudibly cancelled out ..... just like mics out of phase or speakers out of phase.
Thing is, on your git you can't move them around to alter the phase relationship.
Lt. Bob
Spread the Daf!
P90s are single coil and none of them I've seen use magnetized pole pieces ..... the pole pieces are usually screws over a bar magnet just like a bucker.
antichef
pornk rock
Bingo, except for maybe adjusting the height. In my DAW, I have a phase tweaking plugin - hence my initial question of whether I could "adjust" the phase - yes, phase is a binary concept, it's either one way or the other, and two signals that are perfectly out of phase will cancel each other out, perfectly in phase will double the magnitude. But the signals coming from the two pickups are not identical (although they are very similar). I suppose, based on my experience with the phase plugin thing, I was wondering whether there was a way to delay the signal from one pickup slightly in order to affect the application of the phase relationship when the two signals are combined. In the analog domain, I can see why this isn't really feasible (or is it?) - in the digital domain, I suppose the plugin moves one of the waveforms slightly forward or backward to achieve its goodness.
ashcat_lt
Well-known member
Well, the thing in your DAW either uses a full band delay, or an allpass filter to do what it does.
The thing between the pickups isn't really caused by a delay the same way as combining two pickups. It's hard to describe in words, and I can't think of where to find you a picture of it from here at work.
If you imagine the various overtones as sine waves running down the length of the string from the bridge to wherever it's fretted (or the the nut) you'll have the fundamental moving the whole string up or down at the same time. Anywhere you try to pick it up along that length, you will find it moving the same direction.
The first harmonic will be going up for half of its length while going down for the other half. When fretting below the twelfth fret, you'll have the string moving the same direction over both pickups. The neck pickup usually sits right where the 24th fret should be, so if you fret the 12th, you actually get a null in that first harmonic at that pickup. The bridge will get some, but the neck will have nothing to contribute. Fret above the 12th, and the null moves to somewhere between the pickups, and you get the string moving opposite directions over each pickup.
Higher harmonics have more of these alternations between ups and downs, and it gets pretty complex pretty quick, and is complex enough in its application in play that I don't see any good point trying to "correct" it. The right way to avoid the phase cancellations is probably to just use one pickup.
If you draw out that thing I described, you'll also see the reason for the difference in sound between the pickups in general, especially if you draw the various harmonics "to scale" in the proportions that they set up across the string.
Edit -
Wait! I found a picture over at Lollar Pickups site:
The thing between the pickups isn't really caused by a delay the same way as combining two pickups. It's hard to describe in words, and I can't think of where to find you a picture of it from here at work.
If you imagine the various overtones as sine waves running down the length of the string from the bridge to wherever it's fretted (or the the nut) you'll have the fundamental moving the whole string up or down at the same time. Anywhere you try to pick it up along that length, you will find it moving the same direction.
The first harmonic will be going up for half of its length while going down for the other half. When fretting below the twelfth fret, you'll have the string moving the same direction over both pickups. The neck pickup usually sits right where the 24th fret should be, so if you fret the 12th, you actually get a null in that first harmonic at that pickup. The bridge will get some, but the neck will have nothing to contribute. Fret above the 12th, and the null moves to somewhere between the pickups, and you get the string moving opposite directions over each pickup.
Higher harmonics have more of these alternations between ups and downs, and it gets pretty complex pretty quick, and is complex enough in its application in play that I don't see any good point trying to "correct" it. The right way to avoid the phase cancellations is probably to just use one pickup.
If you draw out that thing I described, you'll also see the reason for the difference in sound between the pickups in general, especially if you draw the various harmonics "to scale" in the proportions that they set up across the string.
Edit -
Wait! I found a picture over at Lollar Pickups site:
These both P-94 pickups can be magnetically the same, this case bridge pickup's bare magnet must be reversed.
If pickups will be connected in phase - bass loose must be relatively minimal.
Remember that signals are very different at neck and at bridge and their sum is not absolute in phase.
The same way connection out of phase sum will not be absolute out of phase, but will sound thin.
Parallel connection always is not so bright because pickups are shunting each others resonance peaks, and there are two/DUAL resonance peaks in case pickups are not absolutely identical (what is rare case).
However - you can try SERIAL connection, result will be noiseless, powerful, low resonance, fat, rich signal.
If pickups will be connected in phase - bass loose must be relatively minimal.
Remember that signals are very different at neck and at bridge and their sum is not absolute in phase.
The same way connection out of phase sum will not be absolute out of phase, but will sound thin.
Parallel connection always is not so bright because pickups are shunting each others resonance peaks, and there are two/DUAL resonance peaks in case pickups are not absolutely identical (what is rare case).
However - you can try SERIAL connection, result will be noiseless, powerful, low resonance, fat, rich signal.
antichef
pornk rock
totally stoked - I did the series mod that ashcat walked us through in the other thread. I posted some updated mp3s. My daughter ran off with my headphones and my monitors aren't set up, so I haven't really, um, listened to these, but this a clean and dirty run through - I added some gain to bring things closer to zero - hopefully didn't clip.
the clean should pretty much match what I posted before, except for the new fourth setting at the end. This time I tried to pause so that you could hear the noise or lack thereof. First bridge, then neck, then both in parallel, and finally both in series:
clean:
View attachment CleanP90BridgeNeckParallelSeries.mp3
dirty
View attachment DirtyP90BridgeNeckParallelSeries.mp3
edit - I have not adjusted the height of the pickups/poles since the last recording. I'm about to now
the clean should pretty much match what I posted before, except for the new fourth setting at the end. This time I tried to pause so that you could hear the noise or lack thereof. First bridge, then neck, then both in parallel, and finally both in series:
clean:
View attachment CleanP90BridgeNeckParallelSeries.mp3
dirty
View attachment DirtyP90BridgeNeckParallelSeries.mp3
edit - I have not adjusted the height of the pickups/poles since the last recording. I'm about to now