Modifying the Odyssey crossover - my adventure

[kach22i]

Looks like you really through yourself into this project.

Conrgats.

 

[spectral]

Trust me, it's been rewarding but laborious and you couldn't pay me enough to do it again I have updated the first post with attachments of the woofers' specifications for future reference

 

[Ps68]

This sounds great Peter, very exciting.. It appears that the inductors have continued with the improvements that the caps provided, and all is working well together.

The emotional communication that you mention is exactly what i'm seeking, the holy grail of closing your eyes ( or listening in complete darkness) and genuinely feeling that there is a human presence there in the room with you, feeling the pinpoint location of the emanating textures of instruments and voice.

My ML dealer was over this week, and commented on the speed and precision that these Spires are producing already, so i really am now wanting to get going on mine, ive been told the final bulk of the parts will be in this week.

I think you should do the woofer coils too, what size are they?

Best Regards,
Paul.

 

[spectral]

I think you should do the woofer coils too, what size are they?

Best Regards,
Paul.

They are on order for late January delivery (they have ran out of 14 gauge foils). They are going to be about 7lbs each! and 5.5 inches wide. You have done the best thing by moving the crossover outside the speaker. I will be looking at duelund and caddock resistors at some point as well. Let us know.

 

[spectral]

Measurements

Here are before and after frequency response graphs, and notice how the overall trend is now flat with the upgraded crossover:

Old crossover (Sep 28, 2011):


New crossover (Jan 2, 2012):


These were obtained with the Stereophile warble tones using the RadioShack SPL meter and were corrected per Rives' curve of said meter, using a 62dB 1kHz as reference

 

[Ps68]

That looks more even, the variations will most likely be room induced i would imagine? Good to see some data confirming what we hear, even if it does sound just plain better!

 

[MPS]

It took awhile but now it's done
I have changed all the capacitors in the crossovers except for one - CX3 remains original. It is the Solen PA-MKP-FC 13uF which is not a standard value but it is used in tolerance critical network so I didn't want to mess with it. All others were replaced with polypropylene (MKP) capacitors.

I used different brand and quality capacitors in different circuits based on my evaluation of importance and the original component selection made by ML. For secondary positions I chose to use Jantzen Cross Cap http://www.jantzen-audio.com/html/caps-cross-cap.html ans for primary positions I selected Clarity Cap ESA http://www.icwltd.co.uk/claritycap/esa/details.html both capacitor models have good value/price. There are considerably higher quality capacitors available with some more investment, teflon caps being the ultimate choise.

The black colour ones are Crosscaps and silver ones are ESA. In the photo 47uF Cross Caps are still missing. All others ready for assembly!
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=capacitorbank.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_capacitorbank.jpg" border="0" alt="Photobucket" ></a>

 

[MPS]

I started working with the low pass filters for the woofer elements. Her is a photo of the original crossover layout.
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=OdysseyLP.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_OdysseyLP.jpg" border="0" alt="Photobucket" ></a>
I removed the original 100uF Bennic and 170uF ERSE bipolar electrolytic caps and prepared Cross Caps for installation. There is one 100uF cap and 3*56uF caps parallel total of 168uF. I presoldered all the leads prior to assembly to ease up soldering components inside speaker cabinet. Notice the difference in size!
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=LPMKP.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_LPMKP.jpg" border="0" alt="Photobucket" ></a>
I also measured each component after removal and prior to assembly. Bipolar Bennic's were up in value 5-8uF and both ERSE 5uF, most Cross Caps were below nominal value ~2% quite consistently. Tolerance for original and replacement components was quite good always less than 5% except for bipolar electrolytic Bennic's. Managed to install the Cross Caps quite nicely.
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=LPmod.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_LPmod.jpg" border="0" alt="Photobucket" ></a>
Had a quick sound check after the modification and I could not believe the difference! Bass notes were more thight, controlled almost lean - i was mesmerized of the difference but it was time to get some sleep. Well the next day I still couldn't believe what I was hearing and had to double check everything only to find out that during all that modification I had flipped the switch at the back of the cabinet to -3dB setting, D'oh!!

 

[MPS]

Couple of days later it was time to modify the high pass section. This was the big thing I had been waiting for! :rocker:
Original layout of the high pass section, everything was exactly as in the elecrical diagram. Thank you once more Spectral for posting.
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=HPoriginal.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_HPoriginal.jpg" border="0" alt="Photobucket" ></a>
I also wanted to experiment with optional circuit because I don't generally like using capacitors directly parallel or in series with each other. This is of course a modification not only a tweak. I will not make it public. There is no level or phase difference to the original circuit by ML at the crossover frequency area, only a small level up at around 10kHz but mainly less than 1dB by simulation. Minimum impedance at 20kHz is 0,8ohm or more. Clarity Cap ESA's are the shiny ones to replace CX1 and CX2. One Cross Cap here CX4, could have been higher quality or maybe bypass later with Vishay (maybe a bypass for CX3 too).
<a href="http://s1199.photobucket.com/albums/aa465/makepublic/MLO/?action=view&current=HPmod4.jpg" target="_blank"><img src="http://i1199.photobucket.com/albums/aa465/makepublic/MLO/th_HPmod4.jpg" border="0" alt="Photobucket" ></a>
I used hot glue for fixing everything. Make sure all components and wires are secured and connections are stress free, there can be a lot of vibration inside a speaker.

So did it make any difference? Yes! If I need to summarize in one word - I would say spatial resolution. That's more than one word but anything less would be an understatement, lol It is more easy to pinpoint locations in soundfield, especially in depth and height. There are other benefits too like the highest highs are more crisp but there in no increace in sibilance maybe even less as clearness and cleaness has increased. It does not chance Odyssey to another speaker, only makes it better in what it already is :music:
Everything I have done was done so that it can be reversed and brought back to the original state. One advice for anyone with modification plans, the complete crossover and electronics can be removed and all work done outside speaker cabinet - that's the way to do it nice and easy - next time, lol!

 

[spectral]

Markku - congratulations on your mod. Gotta love neatness, mine isn't nice looking because of all the space constraints and the monster parts installed, but the end-result is just thrilling. You are basically reporting the same sentiments - faster, more vivid rendition.

I had some friends over the weekend who had not listened to my system since last spring... they were blown away by the clarity, lack of grain, truth of timbre and of course the soundstage - and I only had time to play three LPs.

With Paul's (Ps68) mod, we now have more collective positive results to report - and most importantly, they are all consistent with each other - and I hope more ML owners will undertake crossover mods. As you said, it's best to detach the boards and the do the work carefully outside the speakers, unlike my approach (which also strained my back!)

Congratulations again and enjoy! Be sure to report back once the parts have broken in...

 

[Walters 10]

Odyssey

First I have to thanks "spectral" for his beautiful mods, he also give me a inspiration and motivation. I was preparing my Odyssey mod for several years already, but all credit go to "spectral" for all details and instructions. I will try to explain what I did and maybe give somebody else good info or approach. In my mod I replaced all poly and lytic caps replaced binding posts and also did internal rewiring that include removal of -3db switch from + line. My philosophy is to remove all non high-end parts from signal path meaning that I want to make best out of great speaker that I (we)own. "spectral" posted schematic on this thread and we all can see how polluted signal path is, gold plated post with hopefuly copper ring termina and locked with (magnetic) steel nut. On panel side and bas side ML using 16ga I'm assuming some relabeled plastic insulated wire. (is this suppose to be a high end or hi- fi standard?). I'm thinking that all of us are using some high end speaker cables (I gues "spectral" is using MIT configured for Spectral brand audio, I got my MIT Shotgun 750 too). those cabling was selling above $1000. We all should ask ourselves is this our knowledge limitation. I hope that all of you will rethink cabling once more. Al this great equipment and just before our panels (and woofers) go into 2,6,10ft of 16ga internal wire.Do we know any better? How about "Cardas" internal 11ga Teflon insulated audio wire. Above $3.00 ft it is not cheep but it is worth every penny if you know how to work with it. Cardas wire is Polyurethane coated each strand so you need to have some solder pot 450F to burn each end prior to soldering. All this is made by George Cardas and his engineering team.(I’m not underestimating all other great wire manufacturers but this is my choice.). hence this thread name.
:guitarman:

 

[spectral]

Thanks for the kind words. You are absolutely right about replacing the wire and binding posts - I am looking at the Mundorfs at the moment (solid copper) and perhaps Furutech...

BTW, the woofer coils should be arriving next week or so.

 

[Walters 10]

OK Now I have to show "guts for glory" Internally on panel crossover side I replaced all Poly caps with Obbligato Premium audio caps. They are big compared what has been there before. So I had to make room and think how to put it together in relative small board. I used hot melt glue to fasten to the board. A step back, before I removed crossover board out of cabinet I inscribed edges on bass side to see what will be my limitation for bass crossover mod. Obbligato come with aluminum plated housing and it has pretty long leads. I applied Teflon sleeve on all legs just to play safe and still be in high end league. I bypass each cap with .1uF obbligatos. They are nice to work with because they have long leads too. This bypass allowed me to get rid of caps inductance.
I think I read post from Miljac in other thread and he also used Obbligatos on his Ascents. I think that price quality ratio is best buy with obbligatos (with all due respect to Mundorf supreme). It seam that I was able to squeeze it on that board.

 

[spectral]

Woofer inductors have arrived

Beautiful job everyone, just BEAUTIFUL. It makes mine look like an amateur's - which I *am*

So Mr. Walters, can you give more details about your binding posts? I've seen them on other speakers before, are they WBT? Which model? What are your listening impressions???

Meantime, here are pictures of the newly-arrived Mundorf woofer coils, which will be installed soon - 18 more pounds of copper - check out the size of these mothers!





Peter

 

[spectral]

So the woofer coils are installed:




The picture doesn't do them justice, as they are huge; thankfully, there is plenty of room and I had Mundorf calculate their size before ordering.

While the woofer caps removed a lot of overhang, this mod resulted in increased leading-edge response and lower distortion at high volumes, and this was easily demonstrable again: I modified one speaker and played some heavy Reference Recordings bass drums; with the ear next to the woofer you can feel the slam in the cheek - not so on the other speaker. Overall bass frequency response (not shown) is slightly more linear than before and a bit stronger: 1 dB more output at 25-40Hz and 2dB at 63-80Hz, with smaller variations elsewhere; had to turn down the sub one notch to match the previous results.

The speaker now has much more well integrated bass with the panel than the original - if I were to compare the modified O's vs stock, I have a feeling the difference would be startling.

 

[Walters 10]

Great work Peter, Yes I did installed WBT 0702 Binding posts on my Odyssey. As I mentioned before I as planing upgrade couple years ago and at that time cost less then half. They are not signature model (They are more expensive). To be honest with you binding post and internal wire is worth every penny, I hope that you will be able to do the same. Your coils are great step forward especially in bas region. Believe me you will not make mistake if you chose any brand binding posts and replace existing one. Just note that I had some issue with mounting WBT nut on post, keep in mind that I had to open hole in panel to accept 12mm dia. post and nut to fasten need 14mm wrench. So I had to use different tool to lock it. My choice was angled long nose pliers
That really help because c'bore on opposite side was I think 3/4" ( 19mm).
Next to consider how to attach wire ( with ferule) to binding post. As you can see I chose crimping rather then soldering and then new sets of issues. Access to locking setscrew.
I hope that picture will show you how to do it. My suggestion is to use 100% copper binding post or something from WBT or Furutech line. I think it will work for you because you already spend time and $$$. I belive if you put Cardas wire and new binding post you may consider removing -3db switch as well. I think then with all you already did you will not need subwoofer

 

[Walters 10]

I can say what I had before vs. what I have now (>300h) that Odysseys are so smooth detailed and sweet. That I have filing that I don't know why are they in my room (transparent). Sound stage is not associated with them, it is much deeper. My O's are 5ft. from back wall and 3ft. from side. Improvement is great. I believe if I can do any better is to order inductor coils for bass as you did. That may improve on bass linearity. I'm happy that you enjoy your upgrade too.

 

[spectral]

Yes, you are right, only all-copper binding posts will do. The WBT you chose is the best, so nicely done (you really don't want the Signature copper-alloy line). But the short length is an issue, so I am looking at the Mundorf M6 or M8, all-copper and perhaps the gold-plated version. These would probably be a natural choice for me, as the M6s are used on the other side on my Spectral amps. Cardas would have been fine too but they just refuse to make easy-to-tighten-by-hand binding posts. Will keep everyone posted.

PS: The subwoofer is used mostly to smooth the low bass, which exhibits a hump in the 40-50Hz region in my room.

 

[Ps68]

Hi Peter, glad you got the bass inductors in happily, they must have been a bit of a fiddle but well worthwhile I would imagine. If you are after some posts maybe worth looking at Carmine Bocchino's, I know Carmine and know his products are top notch, I can forward some info if you like, just let me know.. I would guess that the M11 and the new Mimas will fit, both pure copper.
Soon time to try some extra weight on your cabs then?

 

[spectral]

Mundorf M6s are in

So as I had calculated, the Mundorfs are a perfect replacement for the stock ML binding posts; below, you can see I am reusing the ML color base "stabilizer" with the prong - no need for extra drilling. On the inside, the hole color fillers are also a perfect fit, and the longer length much appreciated.

Notice the exact same base geometry:




And the end result



All in all, perfect, no-hassle fit! Highly recommended for $40 a piece - I eventually got the gold-plated, all-OFC-copper version. The stock Connex are really low quality.