@chicagoblue1977 - I agree with your initial statement over the trolling (you may be surprised by the numbers of those who agree with you). And will not consider myself worse off without the contention and trolling.
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!
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!
Showing 24 responses by rixthetrick
@
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. |
@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. |
I would implement ERSE audio inductors, specifically one from the Q series.@thecapathian [I misnamed you sorry] - actually I tried to get MC to order the ERSE FoilQ which Erse claim to have even less distortion. Unfortunately Erse have discontinued the Foil Q. I was directing him to the same series of coils you are, just a different model. I am confident that the entire series are great performers, he did choose a highly performing alternative in a suitable gauge. There have been shootouts on inductors and foil inductors have a particular transparency in the signal path, of which I have been informed (rightly or wrongly) is due to the skin effect, or diminishing it’s negative characteristics with the thinner geometry. Some may ask why is it more important on the inductor as the rest of the components are not ribbon or foil conductors?? As air cored inductors generally sound better than iron cored coils, I suggested the foilQ, for reasons mentioned above. Air cored coils (also known as inductors, reactors, chokes) have longer windings (length of wire wound around a core) than ones with an iron core to achieve the same values. [I’ve wound air cored inductors in as large as 10AWG by hand, and not as much fun trying to keep it tight and neat as one might hope.] Specifically my answer is, there is many feet in those windings, a lot more material to affect the signal along it’s path than any other single item in the crossover, or along the signal chain, including the speaker cable. I guess MC will discover first hand whether or not it was a good call?!! Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor and decreases exponentially with greater depths in the conductor. The electric current flows mainly at the "skin" of the conductor, between the outer surface and a level called the skin depth. Skin depth depends on the frequency of the alternating current; as frequency increases, current flow moves to the surface, resulting in less skin depth. Skin effect reduces the effective cross-section of the conductor and thus increases its effective resistance. Skin effect is caused by opposing eddy currents induced by the changing magnetic field resulting from the alternating current. At 60 Hz in copper, the skin depth is about 8.5 mm. At high frequencies the skin depth becomes much smaller.source https://en.wikipedia.org/wiki/Skin_effect |
Name calling like that is unacceptable really, by anyone. Unnecessary. Why doesn't MC simply go outboard with his crossover? I can tell you why I would wait to go outboard, unless it was an intention in the original design (Eric did not design it to be outboard). I would have to determine that the new crossover is indeed superior to the old crossover first. Then I'd have to determine which conductors I'd decide would best go with the lengthening of wires from the crossover. Knowing that in order to correctly implement an outboard crossover, generally terminals needs to be added to connect the extra wires for the three way driver configuration that was implemented in the original design. I suppose sealed pairs of wires could come out the back of the cabinet, requiring engineering and modification of the cabinet. Once such an undertaking takes place, there is really no turning back to restore them to original, as it stands, he can restore to original with a soldering iron, by restoring the original crossovers. There would be no good reason to run all of his internal speakers wires (which are quite a few, considering the array) through his port, and so further modification to the cabinet would be required. That's why I would do it in stages, if I was asked the same question. |
@ rushfan71 - bravo, you used some good quality components. Dyna Mat is a great product. I've never played with No Rez, just read though that it needs to be used carefully? https://forum.polkaudio.com/discussion/159754/installed-no-rez-on-back-and-sides-removed-from-sides Can you put up (even if temporary) a system page with the upgrades you’ve done? I’d like to see the upgraded vs stock as well?? |
MC went about the capacitors differently than I had done in my crossovers (seen in my system page), the two different crossovers (two different pairs of speakers) both employed a use of double wall heat shrink. Where I joined two capacitors in parallel, there was silicone between them, and then double wall heat shrink and siliconed (if it’s not a word, maybe one day it will be?) securely to the board the crossover is built on. **Double wall heat shrink has hot glue on the inside wall.** Either way, MC’s way or the way Mike Lenahan told me to mount the capacitors are a good way to mitigate the ringing inside of a capacitor. An entire thread could be written on such things in crossover electronics, and ways to get the most out of them.... Interestingly: I bought fO.q tape and discs some time ago, based on a thread on Agon actually. As the thread progressed, the claims of snake oil came into the discussion and well, when the package from Japan arrived, I simply put it in the drawer. Seems like I’d better find it and apply it sometime, somewhere?!! @thecarpathian - your suggestion on the Erse was a really good one, and they were exceptional value for money as well. I was more than a little disappointed they’d stopped producing the FoilQ. @millercarbon - are you going to glue and cable tie your inductors to the backing board? That is to help mitigate ringing in your metal coils, by laminating it to the backing board and high tension cable ties. As they are tensioned they kinda act like springs, constantly holding the inductor to the backing board, coupling them. **it also insures that the glue never lets go either, just sayin'! |
@rbstehno MC does have a Porsche actually. https://www.caranddriver.com/news/a32109250/toyota-corolla-gr-hot-hatch-confirmed-2022/ < This Corolla, YES! https://www.youtube.com/watch?v=3a6qawhxuJs&t=77s ^^ 579 hp and 703 Nm to the wheels on 1.6 bar of boost and 98 octane fuel. http://www.speedhunters.com/2012/07/barely_lega/ https://www.autoweek.com/news/g32012546/ryan-tuerck-1000-hp-toyota-corolla/ Those Japs made some seriously bonkers turbo cars that never landed in the USA. I did smile when he mentioned his Porsche, I had a Nissan GTST R33 Skyline back home. I never took it on the track, however I had kart time on tracks with my brother and other work mates. The Skyline wasn’t sold Stateside, well the Nissan GTR-35 is, I’d put up a Nissan Skyline GTR against a Porsche, especially given the same budget. :-) |
@danvignau Are you talking about the 1992-1995 turbo MR2? You can get Japanese ones with no t-top at all, my friend had one, and it was a little go kart. A decent body guy could do a cut and shut and you'd be in the business mate! Hardtop MR2,just like it was factory. Come on MC even if it’s just one photo of where you’re at on the crossover?? I wanna see |
@flynnrd - as you posted directly under a comment by petg60, (I’m guessing it wasn’t a question for me, but the timing was too good to give up) I just went and played Faithless - Flyin Hi. Okay it’s British rap, and it’s mixed like it’s for audiophiles, and it’s not overly crass or vulgar - and I just love that track on my system. I love the surge, the pull, away from the curbHe’s in a 350Z, but it works for Porsche too :-) Peace brov! @millercarbon - oh the mortgage crack was a good one. I won’t be owning a car until it’s paid off, well so long as my employer keeps buying me new GMC Sierra trucks to drive ;-P |
If you can just do two mortgage payments a month, plus however much you can scrape together at the end of a year of clipping coupons eating beans never going anywhere and never buying anything, then in just 6 or 7 years when the mortgage is paid off you will be absolutely astounded with how easy it is to buy really good capacitors.Been Dave Ramsey-ing it for the last three years mate. Over 20% cash for the deposit (no mortgage insurance), no other debt not even for a vehicle. Started out making somewhere between 6 to 8 times in the principle, but after securing 2.625% rate, I dropped back to double principle payments, and banking the rest for investment. *just ta be cheeky* Oh I already have the capacitors mate, cast Duelund VSF with silver foil bypass caps - the pair cost as much as your entire upgraded crossovers. It would be bragging rites if yours weren't as good, or so damned close in quality. So yeah, you're the lucky buggar with the deal mate. |
@ricevs - Air core coils will sound best if you have the signal enter the inside of the foil and exit the outsideFunny, 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 I have never heard the “Apogee” sound, how would you characterise it? What particularly stands out as what you enjoy about them the most? Of course I've heard electrostatics, maggies for example. I imagine they don't go very low, and if that's the case, you're not likely to get the low frequency low buildup and nodes in your room. Do you know what your crossover is doing to the signal coming from the amplifier? I am guessing here, does it high pass bass frequencies and cut frequencies off at the very top end outside of audible frequencies? I saw your system page, thanks for sharing, looks great and I went ahead and searched some of the items online, it was a good read. |
**Sigh of relief here** @millercarbon - not surprised that the Moabs have opened up, and sound better. And yes, it’s going to take weeks for things to settle in as others have rightly mentioned. A positive result immediately is a very good sign of what will come as burn in takes place. You know this, I'm stating the obvious, however in a couple of weeks, it'll be interesting what you experience - Capt. Obvious. When ricevs mentioned the direction of the inductors I though, oh crap did I misunderstand my mentor Mike?? I will have to ask him. @ricevs - if you have information more on the subject of inductor signal direction, or polarity, please share it? I am open to reading more on the subject. I’m pretty sure the testing that was done at our factory on inductor direction was with items with alligator clipped together and going back and forth to determine which was better. I’ll admit there’s a 50:50 chance I heard wrong and made a mistake. I even told MC to investigate it for himself. |
@ ricevs - 9AWG (NINE) now that’s an inductor. Thanks for sharing, very cool. And yes microphonics are a real issue. After mine were wound, I dipped them in a winding varnish that was tested out for it’s sonic characteristics. Next time will be ribbon inductors, and Path resistors. When you do your outboard crossovers, do you also run separate speaker cables to each circuit, so as to not share signal or potential from ground? Run them directly to the output of the amp, my old boss did that on a limited run of outboard crossovers and it worked very well. Of course, he makes ribbon speaker cables, and internal speaker wire, the crossovers have two full runs of 2+" wide ribbon 2.5 metres long. It gets expensive at that point. |
@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 - all this attitude and all you did is ask a simple question, right? It makes sense, that if you already knew that it was such a chore and not a simple thing, you wouldn't have asked, and so you're discovery mode. Sorry to be such a wet blanket, I was trying to inform you as best I could, and without much information about the particular driver you want to swap out. It is a valid question you asked, one I have asked in the past too. It is possible to get a positive result by swapping out drivers, that potential changes proportionally to how well the crossover is designed for the existing ones, and how common the characteristics of your driver to others out there. Can you tell me what the driver is that you want to try and upgrade? |
@
willgolf
- well that's an entirely different proposition than the one I presumed you meant. And yes changing both the crossover and the drivers by someone who actually has the knowledge to do so correctly, makes more sense. If you do choose to do the upgrade, and use a different capacitor, and you're feeling like experimenting?? Might I suggest you get yourself a pair or two of the Duelund silver foil bypass capacitors, and have him wrap one full turn of the legs of the replacement caps and listen, if you like it, leave it in, if not he can easily remove them. Or you could simply cut them off after run in, the wire is thin. Chances are very good that the silver foil bypass caps will give it a positive bump in performance. Google this for yourself, this is truly worthy of some due diligence. He only will need to change the capacitors, and no resistor values? Depending on the space you have on the crossover board, you might ask him to swap out your resistors for Path Audio resistors of the same value. They are universally tested as being the best sounding (at the moment) and introducing the least distortion of any crossover suitable resistors. As you will already have a skilled tradesman there working on the speakers, akin to having a motor pulled apart. The relatively minimal amount of extra work compared to removing the crossover and drivers, would not be unlike putting in a performance part in an already opened up motor. For that kind of outlay, you could maximise your upgrade while he's already pulled it down, and is modifying the crossover. Run it by him, he can decline, or he might give you a significantly better result, maximising your performance / dollar. I almost wrote bang for buck, but your speakers aren't bangers. https://guneytuncer.blogspot.com/2017/03/resistor-shootout-duelund-pathaudio.html Just the first review that I found with a quick search^^ |
@willgolf
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I'm a fan of Duelund, however I've never played with power cords with their conductors. So far their caps are pretty hard to beat (but my goodness they aren't exactly cheap, or cheaply made either). I just came back after looking at your system page... That's one huge fish tank mate! (hehehehehe) And now I really have a connection why you might be interested in the Moab build - I'm smarter than I look (apparently, that's not much of a boast). I'd be interested if you do the upgrade, and what you do. If you do start a thread about it, please be sure and make sure I know about it? |
@ricevs Air core coils will sound best if you have the signal enter the inside of the foil and exit the outside.....either towards the driver or towards ground.I must apologise, I had it confirmed some time ago that you are absolutely correct. I did say mine was wired the other way, which may imply my way is better - it is not, your information is correct. I did find out you are correct at least a week ago. Anyone reading this in the future, follow his good info please. I'm posting this to avoid any confusion, I may have created in my reply. Thank you ricevs, for bringing that to my attention. |