2. misc-audio
  3. 166577-121242

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
danvignau's avatar
danvignau
935 posts
 
rixthetrick   OK, My Supercharged car was a first generation 1988.  It was not available in the states without T-Tops, although there were a few people who did add the equipment on their own to the non-blown car.  I lost to one at the Dog Wood Gran Prix.  Unfortunately, most people did not realize that the engine blocks were different, with the S/C engine block. etc. being much more robust, from a spec series race engine.  My Turbo was a second generation 1993.  You are correct, it was available with or without T-Tops. I owned both cars for a few years  The Turbo is the one I used at the Porsche Club events, although the few series championshipd I won weer with the S/C car.  A former Porsche National champion father and son had a turbo, and showed me a a few tricks for my car, but never quite enough to beat them.  I used B&W (box) car speakers in the former car, with a Soundstream amp. 
     I really like B&W's, having owned at least one set since my early 1970's DM4, which was interestingly a DM2 changed from a ported to a transmission line cabinet.  Both used the Celestion upper mid/tweet and the Coles super tweeter that KEF used in their speaker, as did the famous Rogers min-monitors.  B&W's first speaker was this KEF that was bought to improve the crossover to create their first speaker, the Domestic Monitor.  This B&W, and the KEF from which it was derived, used the squashed 6 x 9 looking KEF woofer that was used to make the cabinet narrower, in order to lower Britain's VAT tax on cabinet width.     B&W then came out with narrow stand mount models (DM 2/II, DM7, DM14, DM16, plus the powered DM14 called the Active One.  Both designs were originally created to lower this VAT tax.     (Added that to make the topic home audio related.)   







teh 
rixthetrick's avatar
rixthetrick
1,060 posts
 
@ricevs -
Air core coils will sound best if you have the signal enter the inside of the foil and exit the outside
Funny, I wired mine signal in on the outside, the core towards ground, I posted the photos in my system page, and that aspect is clearly seen also. I was told the opposite??? I almost had to run the lowest value inductor that way you said, as I had not left long enough leads, but I wound (Andrew Lenehan actually hand wound them, and he's better at it really) a new pair the way they are now.

I do know of an Australian speaker manufacturer who bypasses the spade terminals on the basket by drilling off the rivet that holds the mounting plate on, but it’s how he joins the ribbon internal wire that makes it work so damned well. He’s using a special silicone for vibration isolation on the join.
I did the same on my larger speakers using Jack Bybees bullets, directly wired in. Thank you, good info mate.

Can you imagine the time to do a Tekton array of tweeters eliminating the posts? It took me hours just to silicone mount my bybees to the basket and connecting the tinsel leads on just four drivers - Urrggggh!

And he replaced the aluminum baffle on the tweeter with a polished copper baffle, which gave it a significant increase (I had to edit out my Aussie slang, I forget sometimes I can be hard to understand) , well in performance and cost (copper plate and machining aren’t cheap).


@millercarbon - I sure hope you read that? Now you have conflicting information, something else for you to investigate.

parker65310
212 posts
 
@millercarbon - I would like to discuss with you, if you are willing, crossovers I’m considering for my Apogee Duetta II Signature Series full range ribbon speakers, but I’m on the fence regarding doing it at all (don’t want to lose the “Apogee” sound I’m so addicted to) and, if I do, if I should go with the caps recommended by Music Technology/ Graz in Australia or maybe consider going a different way. The speakers are being sent to Bill Thalmann @ Music Technology for full restoration anyway. I don’t want to potentially (partially) squander the ~$1,200 I’ll be spending for freight (AR to VA). Are you able to private message me? If not, we can take it offline via email if you prefer. Thanks in advance.
millercarbon's avatar
millercarbon OP
12,531 posts
 
Sure. PM coming. But I don’t really "do" crossovers. Barely understand the subject. All I do is swap out parts - caps, resistors, inductors - for higher quality parts of the same value. Done a fair amount of this over the years and with speakers, amps, and other stuff, always with good results. Do it right and you don’t really change the fundamental character of the component much at all- it just becomes a whole lot more clean and liquid, with greater detail and a greater sense of ease. Caps are kind of like tubes or cartridges. The better ones are just plain better, but among the better ones you can choose smoother or more analytical. No matter what you choose even the more analytical of the better caps will seem liquid and make even the smoothest cheap cap sound grainy by comparison.
drbarney1's avatar
drbarney1
180 posts
 
I read in Sound and Vision magazine the half-million dollar Rolls Royce had a sound system which has software giving access to every pop song ever recorded. It excludes classical music and opera because according to some market research too few people who buy a Rolls Royce prefer that kind of music, something few people would expect. That taught me the lesson; entering the ranks of the super-rich is not a gateway to the higher and more human forms of culture.
More to discover