P Bass Pickup Series vs. Parallel Comparison - with Sound and Frequency Response

[Dino Boreanaz]

For a while now I've been curious about how series and parallel wiring configurations affect the tonal characteristics and output level of a split-p pickup. After doing the circuit modelling and simulation with the help of many of the good folks on this forum, I finally got around to doing the wiring changes. I made quick recording of both the series and parallel configurations and the comparison can be found here.

The bass is a 1986 Squier Japan medium scale precision with a G&L MFD split coil pickup, 500k volume and tone pots both at 100%, and relatively fresh nickel plated roundwound strings. I recorded a quick run through of the open strings played with a pick and plugged directly into my interface. I tried to keep my picking location and dynamics as consistent as possible, but the series and parallel recordings are two different "performances" so this will account for some of the variations in response.

Of course there was the expected level reduction in the parallel configuration, so the first run through compensates by applying a +5.0dB increase on the parallel clips to more closely match the perceived loudness of the series configuration. Following that is the same comparison without the level increase. These are noted in the video.

The frequency response graphs in the video are for the entire sound clip for each configuration, so you'll see the same graph every time a particular configuration is playing.

I'm very happy with the change to parallel wiring on this pickup! Due to its naturally high output, I can easily compensate for the level reduction by slightly increasing my amp's gain to achieve the same level and "drive" I previously had with the series wiring. In doing so, I don't find the low end lacking at all, and the additional high end (from about 3kHz and up) adds a nice clarity that I found lacking with the series configuration.

Thanks to everyone who contributed their knowledge, experience, and encouragement.

 

[bassdude51]

I can not comment from experience with a P pickup wired in parallel but I can comment on low ohm bass pickups.

First off, a Jazz Bass. When both pickup are run equally, it is parallel and the combined ohms are about 3.5 K. And we all know how a stock J sounds, don't we? It sounds excellent.

I am the proud owner of a 1953 P Bass 99% stock and it's pickup rates at 5.6 K ohm. No complaints on the sound!

I recently bought an 8.4 K ohm P Bass pickup. Stock Ps are usually around 10.5 K to 11.5 K and I love the sound of the 8.4 K!

So, IMHO, wiring a P pickup from series to parallel..........why not!

Excellent post! Never seen a post like yours, Dino Boreanaz before here on TalkBass.

 

[Jefenator]

Thanks for sharing that!
I wonder how the parallel sound might 1) maintain presence in a dense mix and 2) sound for slap.

 

[pbass2]

Very cool! I'm used to the big 'ol MFD humbucker but have never had the MFD p-styled pickup. My assumption is they also have very pronounced mids(kinda like what you typically get with an "overwound" p pickup), so the parallel setting could make them sound more "airy", maybe even more "vintage". IK with my single-MFD pickup KIloton series is actually too wooly - parallel and single coil are far more usable tones. Analyzing series vs parallel EQ curve looks very similar to your results with the MFD P.

 

[Fuzzbass]

I'm very happy with the change to parallel wiring on this pickup! Due to its naturally high output, I can easily compensate for the level reduction by slightly increasing my amp's gain to achieve the same level and "drive" I previously had with the series wiring. In doing so, I don't find the low end lacking at all, and the additional high end (from about 3kHz and up) adds a nice clarity that I found lacking with the series configuration.

Cheers! I somewhat understand why many say that a P pickup in parallel is "useless" or "sounds terrible", but this is mostly because they make no effort to compensate for the significantly lower output of parallel wiring. "Louder sounds better" as a rule, so the louder series mode will win out in a direct A/B.

Of course the change of mode also results in a change in tone, and many P-bass lovers are looking for that signature "lo fi" mid focus of series. That's my sentimental favorite, but same as you I've also enjoyed the flatter response of parallel wiring. It's a useful option if you have a boost pedal or some other way of bringing output up to match series mode.... or, if you leave the pickup in parallel and set your rig to the lower output (e.g. disengage the input pad!)


The Music Man Stingray 5 came out with a cool innovation: a series/parallel/single coil switch for the pickup. Not only that, but output was balanced between all three modes: I believe that's achieved via the use of a capacitor that lowers the output of series mode to match the other two (but IANA tech, so don't quote me on that).

 

[Dino Boreanaz]

Thanks everyone for sharing your thoughts and experiences!

I wonder how the parallel sound might 1) maintain presence in a dense mix and 2) sound for slap.

I suspect the added range of the parallel sound will work well in a mix, but I haven't tried yet. And I'm not a slap player so, unless someone else borrows my bass, I'll likely never know the answer to number 2.

I did find it interesting that the essential "character" of the instrument remains much the same in the parallel configuration. It seems the extended high end is additional and everything else remains as it was in series, albeit at a reduced level. Which again, for me was a non-issue as I simply increased the amp's input gain from noon to 1 o'clock.

I haven't experimented much with different pickups, but @pbass2 my experience was that this pickup was indeed very low and mid heavy in addition to having tremendous output in its standard series wiring. Wiring the coils in parallel did add an "airyness" or clarity to the tone just as I hoped it would.

You're exactly right @Fuzzbass about people seeming to dismiss the parallel wiring sound due to the reduction in level. For me that was a simple adjustment of my amp's gain control and I got back everything that I previously had with the series wiring plus the additional high end that came with parallel wiring. Since my setup is so simple, I'll be leaving it wired in parallel and I've made the only adjustment I needed to with the gain control.

The Music Man Stingray 5 came out with a cool innovation: a series/parallel/single coil switch for the pickup. Not only that, but output was balanced between all three modes

That is indeed a really cool wiring setup that would allow players to more accurately hear the true tonal differences between the various options without having their judgement clouded by level changes which, as you said, will always lead people to prefer the loudest option.

 

[tidbits]

@Dino Boreanaz I've been running my bass mainly in Parallel - it's really great, and I really enjoy the extra top end. As you've noted there's a bit of a output drop, but it's easily remedied by adjusting the gain. I usually set my board to have some kind of always on tone sweetener early in the chain and I have my two levels for series and parallel marked on a piece of tape.

I'm still in the experimentation phase, but my next build is going to be a double P configuration, mainly to run in parallel. I'm also trying to explore options to attenuate the output while running in series to hopefully make switching a little more seamless.

 

[bigtone23]

Nicely done! Cool to see graphs. Parallel always opens up the top end, but was surprised to see that the series low end wasn't as exaggerated as it seems once the parallel gain is matched.
There's a lot of strong, negative opinions on TB about the tonality of a P pickup in parallel. However, I don't agree. I love the P series sound for what it is, it's iconic. However, since my first split coil equipped P type bass (an '83 Electra Westone I got new), I have wired in a switch or P/P pot to get the parallel option on my P pickups (as well as on Tele Wide Range pickups). The only exception is my 84 P Elite. That pickup and the active preamp in it already have plenty of top end on tap.
This parallel preference is definitely from my love of the Jazz bass and the J sound-the extra air up top is nice to have and easy to roll off if not wanted. I often run just the neck pickup, and a P in parallel is similar.

Another cool reason to have a parallel option on the P...
Take a P/J, one of the most polarizing configurations out there, and often wrongly stated as 'the best of both worlds.' Put the P in parallel and now the tonality is much more J bass sounding, especially in the blends. Put it in series and solo the P, it's a P. That, to me is closer to 'best of both worlds.'

 

[pbass2]

I haven't experimented much with different pickups, but @pbass2 my experience was that this pickup was indeed very low and mid heavy in addition to having tremendous output in its standard series wiring. Wiring the coils in parallel did add an "airyness" or clarity to the tone just as I hoped it would.

Yeah, MFDs are probably the hottest, most mid and low-mid heavy passive pickups out there, next to of course something that is deliberately "overwound". They're known for that! As a result a lot of folks don't take to them. As I mention, I find series in the MFD humbucker to be just a bit too wooly and dark for my tastes (and it's loud). Not sure if you tried this with your MFD P-equipped bass, but most of the G&L heads around here have arrived at never running the volume on the bass at 100%. With it lower, like around 80%, it opens up more, gets more airy and traditional sounding. And that's even true when in parallel. They're very unique pickups, that's for sure.

 

[Zazie Moondust]

Interesting this thread came up right as I am contemplating adding Series Parallel on my own bass. It's got a Model P and a Model J and from all the videos I have seen it seems like hotter more mids/bass heavy pickups seem to benefit from parallel wiring as they tend to sound a little fuller and balanced in parallel.

I'm also curious as to how this works with split J pickups, if the same principles apply. I figure a lot of them would be too weak to sound good, but my Model J is hot and dark, so maybe it'll get the same benefits the P does.

Yeah, MFDs are probably the hottest, most mid and low-mid heavy passive pickups out there, next to of course something that is deliberately "overwound". They're known for that! As a result a lot of folks don't take to them. As I mention, I find series in the MFD humbucker to be just a bit too wooly and dark for my tastes (and it's loud). Not sure if you tried this with your MFD P-equipped bass, but most of the G&L heads around here have arrived at never running the volume on the bass at 100%. With it lower, like around 80%, it opens up more, gets more airy and traditional sounding. And that's even true when in parallel. They're very unique pickups, that's for sure.

Honestly mid and low mid describes the my main basses pickups as well, and they are also ceramic with adjustable pole pieces. I wonder if these same principles of lowering the volume apply to them as well or if it's an MFD specific thing, or if there is something special in the wiring. It sounds like a cool way to get extra tonal range without having to install a tone control (or to be used with a tone control)

 

[Dino Boreanaz]

Not sure if you tried this with your MFD P-equipped bass, but most of the G&L heads around here have arrived at never running the volume on the bass at 100%. With it lower, like around 80%, it opens up more, gets more airy and traditional sounding. And that's even true when in parallel.

I haven't tried that, but it's now on my list of things to try!

 

[pbass2]

I haven't tried that, but it's now on my list of things to try!

It's a G&L thing, I think it's part of the design, makes them really flexible actually. Heck, most passive MFD basses with the vol dimed are hotter than some active basses, and will clip whatever you're running them into! As I mention, I only have experience with the MFD 'bucker, but I've heard that the P-style one is also super hot and kinda wooly (compared to a regular P pickup at least).

 

[pbass2]

Interesting this thread came up right as I am contemplating adding Series Parallel on my own bass. It's got a Model P and a Model J and from all the videos I have seen it seems like hotter more mids/bass heavy pickups seem to benefit from parallel wiring as they tend to sound a little fuller and balanced in parallel.

I'm also curious as to how this works with split J pickups, if the same principles apply. I figure a lot of them would be too weak to sound good, but my Model J is hot and dark, so maybe it'll get the same benefits the P does.



Honestly mid and low mid describes the my main basses pickups as well, and they are also ceramic with adjustable pole pieces. I wonder if these same principles of lowering the volume apply to them as well or if it's an MFD specific thing, or if there is something special in the wiring. It sounds like a cool way to get extra tonal range without having to install a tone control (or to be used with a tone control)

The Model J is a very mid/low-mid voiced J pickup, for sure. And yeah, "darker" could apply. I had them in one of my Jazzes, was cool, but did not sound like a Jazz. If yours is a P/J I don't know how a series/parallel switch would end up sounding, but I have a regular single coil Jazz with a series/parallel switch and I use it in series 90% of the time--sounds killer.

 

[-Asdfgh-]

I've had a couple of Westone Thunder IAs in the past with a series-parallel switch and preferred parallel.

 

[Yahboy]

Model P in parallel sound like Shxt ~~~ underwound 8.8-9.5K sound much better, clean and sweet.

 

[Yahboy]

The Model J is a very mid/low-mid voiced J pickup, for sure. And yeah, "darker" could apply. I had them in one of my Jazzes, was cool, but did not sound like a Jazz. If yours is a P/J I don't know how a series/parallel switch would end up sounding, but I have a regular single coil Jazz with a series/parallel switch and I use it in series 90% of the time--sounds killer.

Model J can sound bright with tight tone when 500K pot in use.

My fully passive mod Charvel Pro Mod PJ has bright enough voice from Model J bridge pickup.

 

[-Asdfgh-]

Model P in parallel sound like Shxt ~~~ underwound 8.8-9.5K sound much better, clean and sweet.

P in general, or DiMarzio in particular?

 

[-Asdfgh-]

It's a G&L thing, I think it's part of the design, makes them really flexible actually. Heck, most passive MFD basses with the vol dimed are hotter than some active basses, and will clip whatever you're running them into!

I'm not sure if being too hot for most practical purposes is very useful as rather than opening the volume all the way and knowing FOH won't be overwhelmed you have to gaffa tape the volume knob in place after soundcheck.

 

[Andrew Hargrove]

Very informative experiment. Thanks for sharing!

 

[Zazie Moondust]

Model J can sound bright with tight tone when 500K pot in use.

My fully passive mod Charvel Pro Mod PJ has bright enough voice from Model J bridge pickup.

My Charvel doesn't sound that dark either. The way I like to think of it is that high pot values kind of sharpen the sound a bit because what they essentially do is make the resonant peak bigger. Stock Charvels have 250ka, and I am think 500k dual volume could not only sharpen things, but be able to soften things when you turn the volume down a bit.

But when wired in parallel the peak gets a lot higher frequencies so you've got a higher peak now in higher frequencies and you can see that in the link charts of the OP. Which has got me half thinking if using a resistor on the push pull to switch pot values could be beneficial. Not sure if there is enough lugs on a standard push pull for that, but a Fender S1 switch might be able to allow series/parallel with pot values switching and volume balancing (with trimpots like in the Nordstrand Justin Chancellor Pre, though I am not sure if those trim pots also turn down the resonant peak)