Music man axis pickup impedance variance affect bass and mid?

[dean701]

Hey, just throwing this out there.
I have 2 EBMM Axis SS models that are painstakingly different sounding. One is a rosewood board and one is maple. I also have a Floyd as a reference. I have the Floyd guitar sounding exactly how I like it and I'm trying to get the others closer to it. The maple SS sounds way brighter (even than the Floyd) and the rosewood board sounds way darker than both.
Now to the actual question:
I measured the resistance of the pickups and the maple is 17.2K and the rosewood is 17.9K. I understand the rosewood/maple disparity but would this resistance variance have any bearing to the darker sound? The pickups are mounted to the same height. I'm going to swap them around since my OCD won't leave me alone but I just thought I'd ask. I have heard that more windings will be bring the bass and mids out more but these are the same model pickups so I was wondering if the resistance had a similar effect.

All in all, if I could get the maple SS to sound like the Floyd, I'd be done. The rosewood can be the odd one out.

 

[DrKev]

That's about a 4% difference in DC resistance, which is well within tolerance and I'd say it's probably under the limit of what's audible. I don't think that alone is your answer. How did you measure them? Through the output jack or directly across the coil? The different bridge and bridge saddles can definitely change the sound so I'm not sure a guitar with a Floyd will ever sound the same as guitar with a more traditional trem. (And this may be stating the obvious but make sure you are using the same cable and signal chain in your comparisons).

 

[dean701]

thanks for the reply. I measured at the output jack with the same cable with the pickup selector set to bridge. The saddles are the same on both Super sports. I was going to try and use Ozone to get a snapshot of the eq of each and play maybe the same chord to try a match eq to show the difference between the super sports. I hate soldering so switching the pickups around as a test isn't my favorite thing to do.

 

[beej]

In general, a hotter pickup is going to have more mids and less treble/bass. As the pickup has more inductance, the frequency window it puts out gets smaller. That said ... as Kev says, those two pickups should be the same and your measurements are pretty close.

Electrically, the Axis should be brighter than the Axis SS. It has one 500k control while the Axis SS has two x 500k controls (resulting in a combined load of 250k). The higher the load on the pickups, the brighter they're going to sound. (The 'resonant peak' of the circuit is going to be shifted upward, making the pickup sound brighter.)

Also- besides the construction, which is going to have a big effect (maple vs rosewood, bridge/saddle differences, etc.), I'd guess the pickups have a different distance to the strings- that's usually the biggest difference in how they sound. Easy to measure and/or shim to raise them up. (Might work on the darker guitar.)

Anyhow- if you're looking to make the brighter guitar sound darker, that's easy to do. Just turn down the tone pot ever so slightly. The capacitor doesn't kick in until the bottom half of the sweep, so by lowering it you're effectively reducing the load on the pickups, moving the peak down a bit, and making it sound darker. If you like it, you can swap one of the pots (say, tone) out for a 250k rather than a 500k. That'll take some of the edge off.

For the the darker guitar, try disconnecting the tone pot- that'll brighten it up a bit. If you like that and want a tone control, you can use a 1 Meg volume pot rather than a 500k. Also, using a lower capacitance cable can brighten it up some (depending on what you use now).

 

[dean701]

In general, a hotter pickup is going to have more mids and less treble/bass. As the pickup has more inductance, the frequency window it puts out gets smaller. That said ... as Kev says, those two pickups should be the same and your measurements are pretty close.

Electrically, the Axis should be brighter than the Axis SS. It has one 500k control while the Axis SS has two x 500k controls (resulting in a combined load of 250k). The higher the load on the pickups, the brighter they're going to sound. (The 'resonant peak' of the circuit is going to be shifted upward, making the pickup sound brighter.)

Also- besides the construction, which is going to have a big effect (maple vs rosewood, bridge/saddle differences, etc.), I'd guess the pickups have a different distance to the strings- that's usually the biggest difference in how they sound. Easy to measure and/or shim to raise them up. (Might work on the darker guitar.)

Anyhow- if you're looking to make the brighter guitar sound darker, that's easy to do. Just turn down the tone pot ever so slightly. The capacitor doesn't kick in until the bottom half of the sweep, so by lowering it you're effectively reducing the load on the pickups, moving the peak down a bit, and making it sound darker. If you like it, you can swap one of the pots (say, tone) out for a 250k rather than a 500k. That'll take some of the edge off.

For the the darker guitar, try disconnecting the tone pot- that'll brighten it up a bit. If you like that and want a tone control, you can use a 1 Meg volume pot rather than a 500k. Also, using a lower capacitance cable can brighten it up some (depending on what you use now).

Thanks for your input. There are a few topics of debate though.
1) my axis floyd has a tone pot. made this guitar not as ice picky and I love it. I was debating doing it for years then when I saw Richie Castellano's axis, I did it.
2) there is some debate of whether wood actually affects tone as much as people think, or it is simply the pickups/electronics that does all the work. Jim Lill did a great video and that caused many to question the current thought process.

3) the capacitor used within the tone circuit fixes the frequencies which can be altered, it is not like it can always adjust everything.

Like I said, thanks for the input. I ran some spectrum analysis between the two super sports and the frequencies above 500 hz are basically the same with exception to some 10k stuff. Below 500 hz is very interesting. The waveforms are similar but one guitar (the maple of all things) has more 60 to 100hz content. The waveforms are somewhat shifted but all the peaks are still there. When I get some time I will post the waveforms.

 

[DrKev]

I have been down the rabbit hole of trying to measuring differences between pickups. It's super easy to pull up a frequency analyzer plugin and get graphs but much of what you see is false or misleading without extreme care if playing a guitar and running it through plugins with stock settings.

Start with comparing the one guitar to another recording of itself with the tone control backed off enough that you can just hear the difference. Un-amped DI'd clean tone. You should get identical results below 400Hz, there should be no content much below the lowest frequency you play (low E in standard tuning is 82 Hz so you want noise floor from 70 Hz down) and the tone roll off should be clearly visible above 800 Hz. If you can do that, you can start comparing different guitars.

If you really want to persevere I can give you more detailed pointers. Hell, I could publish a small ebook.

Good luck!

 

[dean701]

thanks. just spend 2 hours pulling my hair out with fabfilter and ozone. I see your point. Both are not perfect. the 24 band match eq in fabfilter isn't enough bands for the task and ozone has a bug that doesn't help. I would post the graphs here but they would be of little help. It's a dogs breakfast and really doesn't show what I'm hearing. At the end of the day, the super sport maple is close enough to the floyd. the rosewood has this mid thing between 200 and 500 that could be carved out (maybe). thanks for your guidance.

 

[beej]

I've also spent waaaaay too much time down that rabbit hole. Swapping pickups, pots, bridges, saddles, different frets, you name it. It's maddening!

The Jim Lil stuff is fun (I love his vids- they're fun and clever)- some things clearly have more of an effect than others (electronics, speakers ...), but he's oversimplifying in most of his videos so it's not all correct. If you don't believe that the woods and construction have an effect, then run an spectrum analysis of one Super Sport, then transplant the pickups and pots from the other one and compare. Or- just swap necks from one guitar to another- I think you'll find the necks make a significant difference.

On the pots- I think it's still the easiest way to fine tune things, everything else being equal. (Even if they all have 2 x 500k pots, there are going to be some variances, and it all adds up.) Play with some different values and see if they work for you.

 

[headcrash]

I'm kinda on a similar search.

From my Axis Sports and Super Sports, my 2002 Sport HH is the one, that sounds a bit different to the other two (only considering the bridge humbuckers, since one Sport is HSS).

All three are hard tail, all three are maple necks, all three have the solid bridge saddles, and I tried to do my best to adjust string distance on all three the same, to the tenth of millimeter, as good as I could.
Ok, two of them, the Sports apparently, are Swamp ash, whereas the Super Sport is Basswood with maple top.
Irritatingly the Super Sport (Basswood + maple) and the HSS Sport (swamp ash) sound nearly identical on their bridge pickups. The 2002 Sport HH, although sharing the same construction and woods like the 1997 Sport HSS, is considerably distinguishable.

This leads me to really believe, that the woods in electrical guitars do not contribute much to the tone.
There's this German Professor Manfred Zöllner who teaches or teached Electroacoustics (among other, I think), who also is a guitarist.
He published a very extensive book, where he scientifically and experimentally proofed, that the influence of the tone wood on electrical guitars is negligible. I read through some chapter's, but it's REALLY quite scientific (and I am an engineer...), and I don't understand everything

With all this said, and having factored out almost everything, I still wonder: why do Dean's and my, and maybe others' (Axis) guitars sound different, when most or all factors could be precluded?
I for myself haven't been able to find out.
I also find it difficult to evaluate sound after a pickup interchange, since our sound memory is too short.

Looking forward on other people's opinions

 

[headcrash]

The name of the Professor is Zollner, not Zöllner.
And there is an English translation of the book. If someone is interested, here's some info in English

Gitec - Everything about the book “Physics of the Electric Guitar"

Sleuth about among the growing number of translated English-language chapters of the book “Physics of the Electric Guitar” of Prof. Manfred Zollner!

www.gitec-forum-eng.de

But I don't want to get off topic too far here, sorry!

 

[dean701]

I think the proof is in the pudding. Hopefully. There is definitely a difference when recording each guitar playing thev same content. When I get the energy, I'm going to swap mine around...and probably hate it. Lol. Aside from the other suggestions already raised. String choice is also a factor. I'm a fan of elixir Nanos for longevity but despite their claims, there is definitely a difference in sound between coated and uncoated. The nanowebs are definitely warmer than slinkys.

 

[headcrash]

I have used D'Addarios XL110 since virtually forever. I recently thought, why not try Ernie Ball strings. But tbh, I didn't like them. I think, the D'Addarios were a little brighter, which I like.
However, I put new strings on all guitars at the same time to factor this out as well...

Also, I just wanted to add, that the Super Sport H-H and the Sport H-H both are from 2001 (the latter not from 2002, as I wrote above). This most likely factors out any differences or changes over the years.

One thing though, which I haven't checked are the pots. Although I usually disconnect my tone pots, since I don't use them, and like the potential, extra sparkle...). Will report back, when I get to it...

 

[DrKev]

I think the proof is in the pudding. Hopefully. There is definitely a difference when recording each guitar playing thev same content. When I get the energy, I'm going to swap mine around...and probably hate it. Lol. Aside from the other suggestions already raised. String choice is also a factor. I'm a fan of elixir Nanos for longevity but despite their claims, there is definitely a difference in sound between coated and uncoated. The nanowebs are definitely warmer than slinkys.

There is difference in sound and feel between every brand. Many of the basic materials (the plain strings particularly) are all the same but the ratio of winding to core diameter in the wound strings changes tension and sound a little bit, and then we have the different types of windings, e.g. pure nickel wrap, nickel plated steel, stainless steel, maraging steel (M-steel), Cobalt steel, etc.

We have more choices than ever on the string market right now. It's like having a rack of spices we can use to subtlely change our personal guitar recipe. As guitar players we are really lucky that our strings cost relatively little so trying a few sets out is not as prohibitively expensive as it is for bass players.

In my experience the Ernie Ball and D'addario coated strings sound and feel identical to their non-coated versions, they just maintain their bright tone longer.

 

[dean701]

funny enough, both of the SS that I am speaking of are also 2001

 

[headcrash]

I did some further measurements on all my Axis pickups, with some interesting findings, and...well...still no definitive answer to the differences.
I was and am still searching for, why my 2001 AS burnt apple bridge pickup sounds a little hotter and slightly muddy on the lower strings, and why the neck humbucker and all the combinations the pickup selector allows for, don't sound as twangy compared to my 2001 ASS trans gold.
The 2001 trans gold and the 1997 AS HSS sound very, very similar comparing the bridge pickups. Maybe they just feel a little different, what my subconsciousness interprets as a sliiiiightly different sound

Before I did the DCR measurements, I controlled and readjusted the distances bridge pickups to strings, and bridge pickups to saddles.
With the latter I found, that the burnt apple AS, which sounds the most off, had a deviation of 3 - 5 mm. Meaning, the bridge pickup sees a slightly "bassier sounding portion" of the string. The other two were in the same ballpark, within maybe 1mm.
So I put the saddles on the burnt apple nearer to the bridge pickup, to the exact same measure like in the trans gold (not taking care of the intonation).
Of course there is no quick A/B comparison here, but I think it helped a very tiny bit making the PU combinations a little more twangy. And maybe the sound of the bridge pickup improved a little as well, but is still a little louder and this tiny little bit muddier.

Then I did the electronics measuring, including the volume pot (I don't use tone pots so they're disconnected anyway). For the mesuring, the pickups were measured without the pot, of course.

The DCR of the bridge pickups of the burnt apple and trans gold are similar enough, and the AS HSS is quite off. But interestingly the AS HSS and the trans gold sound nearly identical compared to the burnt apple. Also the pot of the burnt apple is a little off (in comparison...).
I had a pot lying around, which measured 550k, so I thought, why not put that, and the neck pickup from the set I bought for the 1997 HSS, into the burnt apple, maybe it helps with the twangy-ness.
Again, there's no direct A/B comparison, but I think all this helped tiny little bit in the (for me) right direction, but I'm still not there yet. Maybe someone finds it as interesting as me
Here's the measurements:

 

[DrKev]

All pickups are within 3% of specification (15 kΩ for neck and 17 kΩ for bridge) which is really close! Even compared to each other the AS HSS bridge and burnt apple bridge pickups (the pair with the largest difference) are within 5% of each other. These pickups are supposed to be the same and are made the same way to the same specifications, so I'd expect these to sound the same all other things being equal. (I may be wrong, but that's what I feel). Of course all other things are not equal.

But I note the hottest bridge pickup (which should be maybe just slightly darker and louder) has the lowest value pot (which will lower the resonant peak just a little). Putting those two things together, I expect the Burnt Apple to be slightly less bright sounding than the HSS, and maybe a hair extra bass and mids. But other differences between the guitars will add further variation too.

Guitars are like kids, or homemade pizza: we can't make them all the exactly the same every time and chasing our tail trying isn't worth it!

 

[headcrash]

All pickups are within 3% of specification (15 kΩ for neck and 17 kΩ for bridge) which is really close! Even compared to each other the AS HSS bridge and burnt apple bridge pickups (the pair with the largest difference) are within 5% of each other. These pickups are supposed to be the same and are made the same way to the same specifications, so I'd expect these to sound the same all other things being equal. (I may be wrong, but that's what I feel). Of course all other things are not equal.

But I note the hottest bridge pickup (which should be maybe just slightly darker and louder) has the lowest value pot (which will lower the resonant peak just a little). Putting those two things together, I expect the Burnt Apple to be slightly less bright sounding than the HSS, and maybe a hair extra bass and mids. But other differences between the guitars will add further variation too.

Guitars are like kids, or homemade pizza: we can't make them all the exactly the same every time and chasing our tail trying isn't worth it!

Hahaha You maybe right !

I also exchanged the pot in that burnt apple AS to a 550k one, so I ruled that one out, I guess.
In fact I ruled everything out, I can think of. Maybe I should have more of these guitars...
If someone needs to loan me his/her Axis (Super) Sport hardtail for like a longtime or permanent loan...I'm here to help