Do active basses have the same mid scoop with both pickups on full as passive basses?

[Killed_by_Death]

 

Another hypothesis, that I've read many many times, is that there's comb-filtering due to the position of the pickups & their audio waves are canceling one another out in the mids:

 

comb, because it looks like a comb when they're perfectly inverted from one another:

However, this explanation holds no water if a buffered mix solves the issue.

 

Edited February 28, 2021 by Killed_by_Death
spelling

[Woodinblack]

It is not a fixed value here, like two perfect waves or a phase difference in a mathematical model. The 2 coils at full volume are in parallel and thus interacting with each other (as well as the strings), and are being presented with different amplitudes and phases of the same frequencies. If you buffer the individual coils, you remove this interaction - all you have is the two waveforms mixed together.

This is what I assumed caused the mid scoop - and I know it well, it was quite strong on the geddy jazz I had, but none of my ibanezes and not on my aerodyne.

It should be apparent on any active preamp that has individual pickup buffering as well as a standard passive mode (I am not sure if that is how it is done on those pickups).

[Killed_by_Death]

Ibanez uses A/C taper blend-pots, & isn't the Aerodyne a P/J?

Also, if there's a passive switch position, it's using a passive blend, so there won't be a difference.

From looking at wiring diagrams of some BTB Ibanez, they have used active blend on some preamps, but I'm not sure if that's happening on new models.

They've recently removed support of wiring diagrams completely & in the past the newest ones available were from 2007.

 

Edited February 28, 2021 by Killed_by_Death
added the bit about passive switch position

[Killed_by_Death]

 

Am I mistaken in thinking this 'phenomenon' is worse with single-coils than it is with humbuckers?

I'm into the split-coil humbuckers & don't notice a scoop with two of those, however the instrument also has an A/C taper blend.

 

[Woodinblack]

1 hour ago, Killed_by_Death said:

Ibanez uses A/C taper blend-pots, & isn't the Aerodyne a P/J?

It is indeed.

I have had other jazzes that didn't have that issue though. Not fender ones.

1 hour ago, Killed_by_Death said:

Also, if there's a passive switch position, it's using a passive blend, so there won't be a difference.

From looking at wiring diagrams of some BTB Ibanez, they have used active blend on some preamps, but I'm not sure if that's happening on new models.

Most ibanez preamps that I have dealt with have a passive blend.

1 hour ago, Killed_by_Death said:

They've recently removed support of wiring diagrams completely & in the past the newest ones available were from 2007.

A bit poor of them really, although most of them are pretty obvious. Unless you got it with no wires!

I am sure most are on the internet somewhere even if they don't come from ibanez. And to be honest, ibanezes documentation is pretty poor at the best of times.

[Killed_by_Death]

 

Until they removed the wiring diagram support, I'd have commented that their documentation is great. They have complete BOMs for each model online:

https://cs.hoshinogakki.co.jp/pcw.nsf

Have not seen another other manufacturer with that depth of detail readily available.

 

[drTStingray]

Just to observe that my experience with active two pick up basses covers two types, both with humbuckers. In the example with a pick up blend knob, eg Musicman Bongo, both pick ups are never on full.

In the example with a pick up coil selector switch they can both be on, all coils. I don't see the scooped sound that creates as a problem, particularly if you balance the mids slightly back into the sound - far from it, it's a great sound and for slap it's the Mark King type of sound. To my un-theoretical mind, having a pick up near the neck on full will add quite a bass heavy sound to the mix of the two so it seems obvious that would need some compensation with reduced bass EQ (by the user). I also seem to recall reading discussions about this subject and the term phase cancellation between the pick ups was a technical term for the interaction. I may have misremembered that....

Anyhow the main point is I don't view it as an issue and use both pick ups on full (as the OP described) as a general rule, but with a small amount of extra mid range dialled in to compensate for the scoop. 

I've never played an active Fender Jazz but presumably if it has a three band EQ you can similarly dial in mid range if you feel the need, with both pick ups on full? 

[Killed_by_Death]

10 minutes ago, drTStingray said:

the term phase cancellation between the pick ups was a technical term for the interaction

That's what I've read as well & corresponds to my post at the top of this page.

 

10 minutes ago, drTStingray said:

small amount of extra mid range dialled in to compensate

IME, 'dialed' in midrange isn't as aggressive-sounding as the real thing from the pickups.

I like that high-mids bark I get from dialing the Nordstrand Big Singles towards the bridge pickup about 25%, that just can't be duplicated with an EQ.

Granted, I can get close with the parametric mids knob on my EHB with Big Splits, but it's not as aggressive-sounding.

 

[Woodinblack]

8 hours ago, Killed_by_Death said:

Until they removed the wiring diagram support, I'd have commented that their documentation is great. They have complete BOMs for each model online:

Those are.

I had commented before about their user manuals. The user manual for the EHB contains information on a lot of bridge and control adjustment, none of which exists on the EHB. It doesn't tell you how to adjust its bridge.

 

8 hours ago, drTStingray said:

Just to observe that my experience with active two pick up basses covers two types, both with humbuckers. In the example with a pick up blend knob, eg Musicman Bongo, both pick ups are never on full.

With humbuckers, the change is different in that you already have two coils connected already, so any other effect is going to be lesser.

 

8 hours ago, drTStingray said:

Anyhow the main point is I don't view it as an issue and use both pick ups on full (as the OP described) as a general rule, but with a small amount of extra mid range dialled in to compensate for the scoop. 

I've never played an active Fender Jazz but presumably if it has a three band EQ you can similarly dial in mid range if you feel the need, with both pick ups on full? 

Its not an issue but it isn't something that can be corrected by an EQ in that although it is a bit of a mid scoop, it isn't reqlly an eq issue. And also only exists at full volume, any change of the volume control will affect it.

 

[FDC484950]

8 hours ago, drTStingray said:

Just to observe that my experience with active two pick up basses covers two types, both with humbuckers. In the example with a pick up blend knob, eg Musicman Bongo, both pick ups are never on full.

In the example with a pick up coil selector switch they can both be on, all coils. I don't see the scooped sound that creates as a problem, particularly if you balance the mids slightly back into the sound - far from it, it's a great sound and for slap it's the Mark King type of sound. To my un-theoretical mind, having a pick up near the neck on full will add quite a bass heavy sound to the mix of the two so it seems obvious that would need some compensation with reduced bass EQ (by the user). I also seem to recall reading discussions about this subject and the term phase cancellation between the pick ups was a technical term for the interaction. I may have misremembered that....

Anyhow the main point is I don't view it as an issue and use both pick ups on full (as the OP described) as a general rule, but with a small amount of extra mid range dialled in to compensate for the scoop. 

I've never played an active Fender Jazz but presumably if it has a three band EQ you can similarly dial in mid range if you feel the need, with both pick ups on full? 

+1. Both of my dual humbucker basses (Fender Dimension and MM Sterling) have a more scooped sound in the middle position (all 4 coils). However it’s not that pronounced, and they both have 3 band EQ (and the EQ is excellent on both basses), so a tweak with the mid seems to sort it. However the un-tweaked sound is killer for both slap and with a pick

[Killed_by_Death]

6 hours ago, Woodinblack said:

It doesn't tell you how to adjust its bridge

I never even opened the manual that came with mine, because I identified it right away as the 'genera' manual they supply with all instruments.

There is this:

 

 

[itu]

14 hours ago, drTStingray said:

In the example with a pick up blend knob, eg Musicman Bongo, both pick ups are never on full.

The Bourns blend pot (type MN) has half tracks. In the middle both pickups are full on.

Active mixers do not necessarily need special pots as the pots are not directly in the signal route.

[Woodinblack]

1 hour ago, Killed_by_Death said:

I never even opened the manual that came with mine, because I identified it right away as the 'genera' manual they supply with all instruments.

Well, yes I worked it out just fine but what is the point providing a manual with a bass that contains no information about that bass? It would be better to have not provided anything as you are just wasting peoples time, it is effectively negative documentation.

[Killed_by_Death]

 

The sheet telling the factory worker what to include in the box states "manual",

and since they haven't developed a manual specific to EHB, the factory worker tosses in 'the manual' that goes with all their instruments

This is what we get with mass-produced instruments, just a fact of life.

 

Has anyone specifically tested single-coil J-style pickups with an active blend & verify there is no scoop?

 

[drTStingray]

9 hours ago, Woodinblack said:

Its not an issue but it isn't something that can be corrected by an EQ in that although it is a bit of a mid scoop, it isn't reqlly an eq issue. And also only exists at full volume, any change of the volume control will affect it.

 

Although I agree that the initial characteristic is not caused by EQ, the net result is a scooped sound, which may not be wholly appropriate dependent on what our band mates are doing at the same time. As far as I'm concerned a minor tweak of my mid range (on the bass) enhances those scooped out frequencies enough to assist, when and if that's required - and that scooped sound is killer as stated by @FDC484950 I used a 3EQ SR4HH as my main bass for over 10 yrs and got very used to this - it's now either an SR4 Special HH as main bass. To be honest the EQ gets minor tweaks also in the outer single coil setting as well (Fender Jazz area of tone). 

I guess if I was using a passive bass, I'd have to alter the setting on the amp. 

My bass is usually on full volume or just below - I've never noticed any variation based on volume - the same sound applies as far as I'm concerned in that setting and very minor EQ tweaks make for an incredibly versatile instrument. 

Edited March 1, 2021 by drTStingray

[Killed_by_Death]

 

Unless you have a parametric mid or just get lucky that the frequency on the EQ is right, you won't be putting back exactly where it was scooped.

I'm a bit of 'cut only' kind of person when it comes to EQ. Get the fullest range of timbre you can organically from the pickups & then cut if you must, but boosting is so inorganic.

 

[drTStingray]

I guess it depends on individual  taste, but it's basically centred or very slight boost - I do realise the exact frequencies won't be replaced but I'm simply after the most usable sounds (for my taste and to fit the songs). I think I said before, I'm a bit inept in terms of the theory behind what I'm doing and the characteristics im countering!  

[Killed_by_Death]

 

The simplest way to avoid the scoop, if that's the goal, is to blend away from center. I blend back to the bridge pickup for that high-mids bump.

Obviously if you wanted that mid-bump in the lows, you'd blend toward the neck pickup.

For a while I was satisfied with a single humbucker, but recently had enough & sold that one.

 

[drTStingray]

2 hours ago, Killed_by_Death said:

 

The simplest way to avoid the scoop, if that's the goal, is to blend away from center. I blend back to the bridge pickup for that high-mids bump.

Obviously if you wanted that mid-bump in the lows, you'd blend toward the neck pickup.

For a while I was satisfied with a single humbucker, but recently had enough & sold that one.

 

Yes me too when using a bass with a blend knob - the one I was referring to has coil selector, and I was referring to either all coils selected or the outer single coils (the latter similar to a Jazz, effectively) 

Edited March 1, 2021 by drTStingray

[Killed_by_Death]

 

Strike one for me not paying attention to your previous post well enough & not being that familiar with StingRay controls.

I remember they had something called 'The Game Changer', not sure if it's still a thing.

 

[Graham]

13 hours ago, Woodinblack said:

Well, yes I worked it out just fine but what is the point providing a manual with a bass that contains no information about that bass? It would be better to have not provided anything as you are just wasting peoples time, it is effectively negative documentation.

There's probably things in the manual they're legally obliged to print and send with the instrument, even though no-one ever reads them - RoHS statement, WEEE statement, disposal instructions, that sort of thing

[itu]

16 hours ago, Killed_by_Death said:

Has anyone specifically tested single-coil J-style pickups with an active blend & verify there is no scoop?

I put a Mixpot to my Modulus Quantum and the change was substantial. If I want to change a two pickup bass somehow, active mixing is the thing. Eq is nice to have but mixing (and a low pass filter) seems to be my road to happiness.

[Woodinblack]

17 hours ago, Killed_by_Death said:

Has anyone specifically tested single-coil J-style pickups with an active blend & verify there is no scoop?

My shuker has two J width (but they are delano humbuckers) pickups and no scoop when both are on with an active blend (in fact, a john east like mentioned earlier), however, it doesn't have a passive mode to compare it too so who knows if it would have it anyway.

[Chienmortbb]

The scooped mids are caused by a numbet of things many of which are mentioned above. The way pickups are wired often on passive  basses means that adjusting the volume also chnages the freequenccy response much like EQ or tone knobs do. In addition (and subtraction) there is a comb filtering effect that will boost some frequencies and cut others. As this is a feature of both the response of the pickups and the postion of them, there is little that can be done to mitigate the effect e3xcept  find two pickup version of a Westone Rail.

The comb will happen whether the bass is active or passive and irrespective of whether each pickup is buffered independantly.

[Lfalex v1.1]

2 pickup Westone rail... awesome.  I guess you'd need 2 original ones and remove the pickup module from one and fit it to the other... Or fabricate (3d print?) A second.

Not sure how you'd wire the pair. Y cable into a home-brew blend..