If your Mesa 4x12 is fizzy/harsh, or you want for more mids, this post is for you. Series/Parallel Bogner treatment!

[Nigel]

So I got a holy grail 2003 OS Rectifier 4x12 and have loved it. Wanted to see what it would sound like with Bogner treatment, and my god, it's a whole new level of cool.

The jackplate has your tone going through a Switchcraft jack which has a open circuit that closes on a small contact a little bigger than a ball point of a pen. It's what closes the circuit to join the two vertical, parallel wired 2x12 stereo pairs in series.

So I installed a single jack, 10 gauge Sound Runner 238 strand copper, and some auralex foam on the back panel.

All I can say is I prefer the sound of two 2x12 series pairs. It's like having two 16 ohm 2x12 cabs. I do like the other sound for metal, and thanks to the Aiken diagram, I can fit a switch in it and go back to the stock sound with ease.

In short, the cab feels more organic and open, alive, less harsh and fizzy.

 

[dead-pan]

How does the foam effect the sound?

Had a 4x12 Rivera that had batting stock and it killed the high end harmonics.

 

[thegame]

Nice job and good for you on getting rid of the garbage stock Mesa wiring harness. But...I believe your new wiring method is still parallel/series, as per this diagram:

https://www.scumbackspeakers.com/faqs/scumback_4x12-par-series-wiring_4.pdf

As opposed to:

https://www.scumbackspeakers.com/faqs/scumback_4x12-series-par-wiring_4.pdf

The 10 awg wire is probably too thick to have both + & - summed at the jack on both terminals like in the vintage correct series/parallel method shown on the Scumback site. So, for your convenience here's another way to wire it series/parallel:

 

[the4thlast1]

Over the years of messing with 4x12s . Changing speakers and trying different wiring configurations. I found that the diagram directly above my post sounds the best to me. I have tried parallel series also and went as far as to have a switch in place that would go back and forth between them.

 

[Nigel]

How does the foam effect the sound?

Had a 4x12 Rivera that had batting stock and it killed the high end harmonics.

It doesn’t kill harmonics, just standing waves. Keeps the highs smooth and clear.

 

[Nigel]

Nice job and good for you on getting rid of the garbage stock Mesa wiring harness. But...I believe your new wiring method is still parallel/series, as per this diagram:

https://www.scumbackspeakers.com/wire.html

There it shows both parallel/series and series/parallel.
The 10 awg wire is probably too thick to have both + & - summed at the jack on both terminals like in the vintage correct series/parallel method shown on the Scumback site. So, for your convenience here's another way to wire it series/parallel:

View attachment 279086

It’s the Aiken, adding a wire makes it P/S. Single lead from the jack is deceptive. Note it goes to each positive and negative terminal, then another lead goes vertically from those to their respective counterparts on the next horizontal set. That’s the parallel. Leads then go from the positive to negative terminals of the horizontal sets making them series pairs. Crafty Randall!

 

[Bash_Man]

Where did you get the sound runner cable from ? I've been looking for a while now and haven't been able to find it through any reseller.

Thanks

 

[dave74]

I wired my 2000 mesa 412 to be 8ohm s/p mono-only using the stewmac wiring on page 2 here.
There would have been no reason to do this but the main input jack needed replaced and I was doing an X-pattern k/v mod anyways, so for me the simplest method was the best.

https://www.stewmac.com/globalasset...wnload-pre-wired-speaker-harness-instructions

 

[psychodave]

It’s the Aiken, adding a wire makes it P/S. Single lead from the jack is deceptive. Note it goes to each positive and negative terminal, then another lead goes vertically from those to their respective counterparts on the next horizontal set. That’s the parallel. Leads then go from the positive to negative terminals of the horizontal sets making them series pairs. Crafty Randall!

I’ve always wanted to wire up a cab like this for versatility.

 

[Nigel]

Where did you get the sound runner cable from ? I've been looking for a while now and haven't been able to find it through any reseller.

Thanks

Personal stash I’ve had for years.

 

[Nigel]

I wired my 2000 mesa 412 to be 8ohm s/p mono-only using the stewmac wiring on page 2 here.
There would have been no reason to do this but the main input jack needed replaced and I was doing an X-pattern k/v mod anyways, so for me the simplest method was the best.

https://www.stewmac.com/globalasset...wnload-pre-wired-speaker-harness-instructions

What tonal difference did it make to your ears?

 

[BeZo]

I did the same to mine, but I always tape off the empty holes with electrical tape so that air doesn't go in and out. That's kinda the secret sauce of Mesa cabs is all the gaskets sealing their cabs. They even have plastic caps for the jacks you aren't using. On mine, I just replaced the jack plate with one that has a single hole for a single jack. Done.

 

[Nigel]

I did the same to mine, but I always tape off the empty holes with electrical tape so that air doesn't go in and out. That's kinda the secret sauce of Mesa cabs is all the gaskets sealing their cabs. They even have plastic caps for the jacks you aren't using. On mine, I just replaced the jack plate with one that has a single hole for a single jack. Done.

That’s exactly what I did!

 

[1984_5150]

Bolt shut empty holes lol.

 

[dave74]

What tonal difference did it make to your ears?

Not sure how or if the wiring changed anything, but the X-pattern with the K/V combo definitely added some tightness and thump to the upper bass frequencies. It also added a bit of sizzle to the highs which many people probably would not prefer, but I always felt that cab lacked a bit in that department anyways.

The cab had all the OG basket-stamped V30s which have those amazing mids, but since I was used to my newer 2011 straight-baffle rectifier 412 the older cab always sounded just a little muffled in the treble area, so to me it was an improvement or at least something different to work with.

 

[Nigel]

Bolt shut empty holes lol.

That’s fucking metal as fuck.

 

[Nigel]

View attachment 279086

BTW this diagram is parallel at the speakers and series at the jack, or parallel/series. The equation literally states 4 ohms + 4 ohms = 8 ohms.

 

[skoora]

Not sure how or if the wiring changed anything, but the X-pattern with the K/V combo definitely added some tightness and thump to the upper bass frequencies. It also added a bit of sizzle to the highs which many people probably would not prefer, but I always felt that cab lacked a bit in that department anyways.

The cab had all the OG basket-stamped V30s which have those amazing mids, but since I was used to my newer 2011 straight-baffle rectifier 412 the older cab always sounded just a little muffled in the treble area, so to me it was an improvement or at least something different to work with.

So your saying someone's holy grail is someone’s spittoon?….lol

 

[Nigel]

So your saying someone's holy grail is someone’s spittoon?….lol

He’s saying the v30’s may be for sale.

 

[dave74]

Yeah I'm not a believer in the older cabs/v30s being always better. With some amps they might be, and it always depends heavily on which guitar/pickups are running into which amp, and with which boost/od is feeding the front. I think they are all good when the right combination of gear is together and is dialed-in well. Also I've always been a fan of having a bit of slop in the lows and spit-fizzle in the highs. I like my tones nasty, not tame and trim.