Millercarbon's Mega Moab Mod Meander


One of the all time great automotive engineers, Norbert Singer, was a key player in every one of the 16 Porsche LeMans victories from 1970 to 1998. His dominance was such that at one point Porsche had won LeMans more than all other marques combined. This was all accomplished by building on the already solid foundation of Porsche production models. The air cooled flat 12 in the 917 was really two flat sixes combined to make 12. This car so dominated motorsport the rules had to be changed to stop it!  

So Norbert Singer modified Porsche production technology to extract the absolute most for racing. His legacy is today’s Singer Vehicle Design https://singervehicledesign.com Norbert doesn’t make for a very good car name so they called it Singer. What is a Singer? It is a modified Porsche. It is in essence a hot rod. What Norbert Singer did was make the most hot rod racing Porsche. What Singer does is take that to the next level, capturing every aspect of Porsche right down to excellence of design and aesthetics.  

I am not anywhere near the level of Singer. But that is the spirit of what we are doing: taking an already world-class design and hot-rodding it to be even better. Well, better for me anyway- or so we hope!

The early modders started with substituting off the shelf parts to get more power or less weight. That is pretty much all we are doing here. Would be cool if some day people are doing this with a lot more sophisticated approach. Maybe they will. Maybe even I will. For now though we have the current crossover project.

My approach is pretty simple: better parts sound better.  

This lesson was learned back in the late 90’s with Linaeum Model 10 speakers. The designer had a new tweeter and told me how to modify the crossover for it. Simple mod, one cap, one resistor. Bought the parts from Radio Shack, put it together, sounded like crap. Absolute horrid crap! Called him up, he said those parts are crap. Said Musicap, Vishay. But they measure the same? Just do it. I did. It worked. Even though they measure exactly the same, the sound difference is off the charts.  

Even though they measure exactly the same. There is a lesson here. For those willing to learn.

So this is the essence of it: Eric Alexander has made a speaker the equivalent of a Porsche 911. Even better: an affordable Porsche 911! But after a while with my 911, after learning what makes it drive and feel the way it does, it was only natural to change the shocks and torsion bar and other items to bring out even more of what I like so much about the 911.  

That is what we are doing here. Hot-rodding a speaker. Thank you Rick for the metaphor!  

The parts are on order. Next week the fun begins!
128x128millercarbon
They are related, which is why they are written up the way they are in the OP. Also Eric is a car guy, I’m sure he gets it.

The current 992C4S is one of the all time great driver’s cars. Well, it is a 911 so that goes without saying to one who know cars. But few do, so I am here to remind. To the average person the car is so fantastic there is nothing more to do.

Me, I drive it and after a while determine what tire pressure gives me the best tradeoff between responsiveness, grip, and ride. One psi makes a difference. Certainly not to everyone. Others can do what they want. There are those who are in denial about fuses and directionality, and there are those who are in denial about the importance of working vs cold tire pressure. Plenty around just like that. Oh well. They save a lot of time and money by not being too discerning, so it all balances out I guess.

One of the things that makes the current generations so great is PASM- Porsche Active Suspension Management. PASM monitors driver inputs- steering, braking, throttle- and compares to sensors telling it what the car is actually doing. PASM then actively adjusts in real time shock damping, and roll stiffness and even engine motor mount stiffness, to deliver the best balance of ride and performance.

As determined by the factory. That is key. Porsche tunes these things for the widest range of drivers and roads and road conditions. A huge amount of engineering goes into making the car safe for people who have a driver’s license but do not in fact actually know how to drive. That in case you are wondering would be you, gentle reader. (I make exception for Eric and the few others with track time. That’s about it.)

So just as there are aftermarket chips to get more horsepower, there are also kits with firmware to improve handling by reprogramming PASM. The amazing thing is these not only improve track performance but also in many cases real world ride comfort.

That is all I am doing. Everything I’ve said about the Moab is true. Fantastic speaker. Vast majority of speakers out there have cheaper parts in their crossovers. The parts quality Eric uses is roughly equivalent to the $16k Talon Khorus I had before. Still, they are cheap compared to what I am using.

I know autocrossers who replace the entire suspension on their 911. The car looks exactly the same, but it drives so much more responsive you cannot believe. It ain’t cheap to do this. But it takes an already great car and elevates it to where the only thing better will be another car expertly breathed on. That is all I am doing.

And yes it will be better. Probably so much it is hard to believe. If I don’t screw the pooch! And if I can fit it in there! It is a real tight fit.
If I don’t screw the pooch! And if I can fit it in there! It is a real tight fit.
Oh, my.
I hope you're still talking about crossovers....
https://www.google.com/search?q=rolls+royce+with+chauffeur&sxsrf=ALeKk00msiPWpvkpdSVP12dwNKMb5G8...

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Chauffeur Please!!!! :-) I don't care to drive anymore. Did it for a living I BACHED more miles than most folks accelerated forward. I guess you call it driving. I call it herding..

One incident DRIVING involving another piece of iron. Chrysler LeBaron
22 years ago. Dented a rim on a 15 ton service truck (drove home on it) and broke the ornament on his hood. Drove me into a curb.. I chose the curb vs his FULL front end... He was sited for distracted driving, his third wreck at the SAME intersection... The cop was just SMOKING.

The guy continued to talk on his cell phone until he was told to hang it up or "Go To Jail", he almost got a "Reckless Driving". HE should have had his license pulled right on the spot.. Admitted to being in THREE wrecks at the same intersection... The paint wasn't dry from the last wreck.. Still wasn't buffed...YUP..

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How's that crossover coming along MC?

You're using an IC or going point to point on your new larger boards? I couldn't sort out if it is Point to Point or an IC (you know with traces) You're mounting them inside?  INSIDE? one more time INSIDE!! :-)

As I tipped a pair of speakers over (410 pounders) I was thinking, my new rear pole for the modified bipole could house the internal XO inside that box. Then I thought about it a little more and said.

A WHOLE NEW BOX. because I can't get the NEO 8 Driver fields far enough away from the XOs. BIG and or STRONG magnets have a 6-10" field.. According to my little experiment (mag compass) I know there is an issue running coils parallel. I also found HEAVY mag fields can change the XO parameters if they are too close. There are TWO serious drivers pretty close to the internal XO (existing bass section that is still intact).. and at right angles to one another..

I'm going External... On the fly changes and ease of location.   No other way around it for me..

Regards
@willgolf

MC - just a question or two...you have a wonderful system that is geeked up to the max. Then you buy the Moab’s that you have basically said is the greatest bang for buck speaker on this planet. Now you are taking it apart and adding more upgrades. Are you really going to be able to hear a difference? Where is the point of listening diminishing returns given your current system set-up? Okay, i know it’s a hobby!
Is he really going to hear a difference?
They are a value added speaker, and in their price bracket they do represent large value.
The difference will not be subtle, assuming the build has no flaws (this isn’t his first BBQ, perhaps not the best saying, as he does a LOT of BBQ apparently), the integrity of the original signal from his amplifier should have significantly less distortion introduced by these top tier components. Which are the best quality (or closely rivaling) that I am aware of.

There are only a couple of things that I have concerns for, DCR might change slightly, and MC measured the delivered crossover, not from the plan Eric designed. I cannot see how it will sound less resolving and many reasons to believe it will be more resolving.

Using a car as an analogy, control, braking and horsepower (when it’s needed) are all upgraded simultaneously.
@ oldhvymec  - yeah, external is the best if you can get away with it.
Always compromises though, like using a stereo amplifier the speaker wire runs need to be longer than two mono blocks.

The wire runs will be longer of course. Are you going to shield yours coming out of your x-over?

The driver's magnetic field when the driver is under load, does that change?
I ask because generally the magnet is attached at the rear of the basket, I had always assumed it was a constant magnetic field, and the motor has an electromagnet that changes polarity to drive the cone?

I have suggested MC use variable resistors to test it, before finalising the values in each circuit. I do realise that one could spend a lot of time doing that.