MEC "vintage humbucker" streamer pick up (M RB 60160 4P AB45) magnet swap/replacement

[Danage]

I'm going to put this here, just for the sake of information should any ever have a desire to do the same thing. I swapped the magnets out on the aforementioned pickup, replacing the ceramic magnets with Alnico 5 to see what the difference is. To summarise, the output drops noticeably, and the main voice of the pickup moves up somewhere around the 1k range (to my ear at least). It starts to sound a bit like a Precision Bass pickup, but with less bottom end. I think a lot of the output in this pickup comes from the strong ceramic magnets, rather than the copper wire. Anyway, he's some pictures of the process should anyone else be mad enough to want to do this. If you are, you'll have to look at bar magnets for 7 string humbucker pickups to find something close to fitting. The original magnets are 67x13x5mm, which seems to be quite non standard. I got hold of a pair of A5 68.5x13x5mm and ground them down.
 

[Danage]

Cermag LTD will make custom size magnets however you want... so I've ordered a couple of neodymium ones that will fit this pick up... will report back once I've tried those ones... 

[Danage]

I have got hold of the neodymium magnets, installed them, wired up the pickup to the bass and ran through my bands current set list. Here's what I can advise of:

To start with, I should describe what this pickup is like prior to modding, for those who are unaware. It is a pretty typical soapbar sounding thing, if more on the obnoxious rather than smooth sounding side of things. For the design, I'd expect it to have a resonant peak somewhere about 3-5khz, but it also had a prominent lower midrange. However, rather than help solidify the bass frequencies, it was always problematic for me to tame those frequencies to where they were useful and not obtrusive.

And to get this out of the way... don't do this at home unless you've got a pickup you're prepared to potentially destroy. Maybe getting some magnets and just slapping them on the bottom of the pickup would give an idea of how a stronger magnets will change the sound, in a non-permanent fashion. If you really love the sound, proceed at your own risk to make the mod permanent. 

The magnets installed were "N38" grade. What strength that is compared to what is used in a Dingwall pickup, or compared to a standard Ceramic C8, I don't know. But what I can say is that it is a crazy-strong magnet. I had to slide them apart upon arrival as the pull was too strong to pull them apart in opposite directions. I think it's also fair to say that this pickup design is clearly not suited to magnets this strong, as the string pull is tremendous. The pickup was installed into a bass with the following signal path:
Pickup >  series/parallel switch (set to series) > preamp bypass switch (set to bypass)> volume control > output jack. 

Initially I set the pickup height to 2.5mm below the bottom of the G string when fretted at the 24th fret. However I soon doubled this, and found no detrimental affects to the tonality. 

What my ears tell me:
-The lower mid hump is gone.
-It is still a very mid-forward pickup, but that midrange is now somewhere around 650hz and above. And those frequencies really dominate the sound. It's not a "cocked wah" type sound, the Q is too broad for that. With an amp's EQ flat, and boosting the bass a little bit, it gives a sound that would be good for a bass solo. In terms of the 7 bad system dwarves, we've got a lot of Honky and Barky here. 
-The 30hz and 12khz sliders on my EQ pedal now sound like they actually do something. There's not a whole lot of audio information to be heard in there, but previously there was none. 

In short, it's an improvement because the problems it throws up are not as troublesome as the ones it has removed. I find it easier to get the sounds I'm looking for now. 

Edited 1 hour ago by Danage