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
@willgolf - There's a lot of unknowns in swapping out drivers in a loudspeaker. First thing I'd consider is the fact a decent designer is going to choose drivers that compliment each other in a multi driver loudspeaker.
Crossover points, anti-phase, and the resulting frequency response are chosen and then developed after listening based upon the characteristics of the drivers chosen in the concept stage of the speaker design.

Can a driver swap out result in a better sounding loudspeaker, yes, and depending on how well integrated that driver is in the overall design, no, not at all.

There's a few unknowns that affect the final result, cabinet design (volume for one), port design (if it uses porting), impedance and also the response and efficiency of the driver. It can be like playing with a Rubiks cube, you may get one thing better and three things not.

I do know of a speaker designer who can swap out drivers, selecting replacement drivers suitable for the volume of the cabinet, for example, then completely redesign the crossover to suit. This takes a lot of time to do correctly, and you are essentially creating a entirely new loudspeaker, with different crossover points, and change the balance of energies to try and bring the response curve into something coherent.

Researching a replacement driver with very similar measurements and characteristics, could help you find one not requiring changes to the crossover to get a better sound, I'm just saying that simply buying a better driver doesn't mean an increase in performance.

There is a synergy on how multiple driver speakers interact, and the crossover and cabinet are hugely determining factors.
Having measurements of the driver you're wanting to replace, certainly moves you closer to finding a replacement, it's a starting point.
willgolf-
A question for MC or anyone...if you had an opportunity to replace the drivers or all of the components you worked on what would you do if money was not an object.  Where do you think the biggest bang for the buck is between the drivers and the caps/ resistors etc?
 
If money was not an object I would call Eric say build me your SOTA Assault Speakers, stat, only make em all Duelund and Path, designed with outboard crossovers and hang on I will be sending you some stuff to go in there. I would call Max say build Eric some F1wires for internal. I would call Krissy say you want to see Utah? Cuz I am flying you out to paint and stuff just load em up, Quantum those suckers to the next dimension. Oh and then you are going on to Texas where you do the same with Dave, since money is no object he will be building me some sweet Raven mono blocks to be run off the Allegri Reference pre-amp Max will be making. Which you can then fly to the UK to massage, or come do your magic here, your call, just so I get my Krissy magic.

This was a huge bang for the buck. It was however a lot of work. No doubt about it. For less effort but a lot more money all Be drivers would be a no-brainer. But I like Plan A a lot better.
On my Alon Lotus SE mk ll speakers, I can swap between an AlNiCo magnet and a ceramic magnet on the dipole tweeter in a matter of minutes and the results are not subtle! The AlNiCo is much more refined with better definition and weight to instruments and overtones. The ceramic is still very good but lacks definition when compared to the AlNiCo. I would love to get the AlNiCo magnet woofers but sadly they are as rare as hens teeth and not many were made. One could choose between a 4 ohm woofer or 14 ohm woofer at time of purchase. I have both and the 14 ohm woofer is more defined and mates better with tube amps. The 4 ohm woofer mates up with SS amps and has great bass slam but lacks just a bit of definition IMO.

https://lh3.googleusercontent.com/proxy/xrrDtNBfJroe82wPM8YSNRzULz0vt8Wjm8TauGv2Yhbu3S7CzSdgauct3Exx...
Just changing drivers does not work completely, and most likely some values in the crossover have to be changed and that would require the help of the manufacturer. In speakers with multiple drivers it is a task.
Why not just get better speakers? For all time and labor costs, I would think it would be worth it.

Unless of course you want to be a speaker designer.....