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MGIII active crossover?

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Hi everyone. I'm new here and to the Maggie world. I got a set of MGIIIs that need an almost total rebuild which I will start this week. They were without any of the 3 external crossovers. I recently purchased a Marchand 2 way active crossover and a Mac MC7106 6 channel amp. My intention is to bi-amp (not bi-wire) the Maggies. I will be running everything through the near top end Pioneer H/T unit that has pre-amp outs and will most likely use the Velodyne 12 sub. The Marchand requires that I purchase the exact module which is only $9 for the proper XO frequency. From reading here it seems like that would be 300HZ. Is this correct? Or should it be a little different/
FWIW I read Andy's posts (and others) on crossovers but my deal is just a little different.

Thanks everyone.
Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity

Follow Ups:

Martin Logan - Skeepowder 16:46:00 08/16/16 (8)
My plans took a left turn. I purchased a set of Martin Logan Prodigy, ML Scripts and a ML Theatre I which is a really big center channel speaker. I am trying to get that sorted now. I'll return to the Maggie in a bit.
Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
- RE: Martin Logan - Satie 00:53:26 08/17/16 (5)
  Great set you got there.
  
  These are better than the 3A but for the bass integration still being off compared to the more recent hybrid speakers from ML
  
  Congrats!!!. Hope they don't blow up your budget.
  
  .
  - RE: Martin Logan - Skeepowder 07:25:11 08/17/16 (4)
    Thanks everyone. I called the PO on this equipment and he was ready to sell so I got a great price. It wasn't until 8 last night that I could arrange for a helper to get the really heavy Prodigy base units into the house. I still haven't hooked them up because I need to move some other stuff around. Bi amping these will require some RCA "Y" adapters because I will need to split the pre-amp signal into 2 so it will feed both amp channels. The new center channel is 43" long and won't fit in my entertainment furniture at all. And the Scripts are wall mount. Let the fun begin.
    Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
    - RE: Martin Logan - Satie 19:48:15 08/18/16 (3)
      Tell us how it goes when you have them setup.
      - RE: Martin Logan - Skeepowder 14:10:48 09/11/16 (2)
        
        In Reply to: RE: Martin Logan posted by Satie on August 18, 2016 at 19:48:15
        
        I'm back. Just went thru a busy time with learning to kayak, hiking in the Olympics and all. I haven't done diddly to the Maggies. I still have the MLs connected to the Pioneer and they sound great taking in the ht limitations. I haven't been able to find a good rack or shelf for my Mac and other stuff. The only place to put it is on the low tv shelf and we have 2 dogs so it gets dusty down there. The Mac is really clean so I would like to keep it that way. The big news is I just purchased a vintage Pioneer SF-850 active crossover on eBay which should be here this week. I was watching the site for quite a while and a few good pieces came through. A Luxman tube XO, 2 Pioneer SF-700s, and there's a Pass/ Threshold there now for $1400. There's always Behringers and the other modern pro gear but I wanted something from the good ole days. The goal is to sell most or all the MLs while making a few bucks and keep the Maggies. I was using the lack of an XO as the excuse not to finish the Maggies but that doesn't work now. I better get going on that now. LOL
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: Martin Logan - Satie 01:14:24 09/12/16 (1)
        
        In Reply to: RE: Martin Logan posted by Skeepowder on September 11, 2016 at 14:10:48
        
        SF850 That is a wonderful piece - you can do asymmetrical slopes and it has a flat setting too. Ideal piece for your project. Just be sure the power supply electrolytics are in good condition before you use it. It should be sme 30 years old...
        
        So the ML speakers didn't rock your boat? They should outdo the stock 3A easily enough. Just need your Macs setup to power them.
        
        RE: Martin Logan - Skeepowder 07:02:25 09/12/16 (0)
        
        In Reply to: RE: Martin Logan posted by Satie on September 12, 2016 at 01:14:24
        
        The MLs are fine speakers and I did get the package for a really good price. But it was thousands more than the Maggies will cost even with the new XO. I can afford the MLs but I'm not sure if I want to afford the MLs.
        I would like to A/B the 2 sets though just for fun. The powers that be kicked me out of my Maggie work space just this weekend mainly because there was no work happening. I can set up elsewhere but need to move some stuff around.
        And I gotta get the Mac setup somewhere, and the cd and the sacd and I would like to get a record player and that XO has to have a home. And might go sailing today on my boat that I sold last month.
        Damn, retirement is ......Busy!
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
- The Martin logan Prodigys and the scripts are fantastic speakers - Michael Samra 22:22:01 08/16/16 (0)
  I have Monolith 2s I've used for years and then 6 years ago I ended up getting a pair of CLXs. I use a pair of ML Descent subs with them because they are Panel only speakers.The Monolith 2s I have are custom and those are a panel only as well.
  I run them with a pair of vintage HK Citation 2 tube amps strapped in parallel and it's actually quite dynamic but of course I upgraded the amps with the McShane mods.The Magnepans are also a great speaker albeit a bit less efficient than the ML,the Maggies are easier to drive because they are a purely resistive load. I almost bought a set of Prodigys because I didn't want to buy speakers like the ML Summits with a built in amp.Of course, the subs have built in amps but they allow me to use tube amps on the panels which is where the vacuum tubes shine.I can also use the output signal from the tube amps to drive the subs.You bought some very nice stuff and if you set it up right,you will be very happy.
  
  "For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
  
  Edits: 08/17/16
- RE: Martin Logan - Norman M 21:49:53 08/16/16 (0)
  Might not you have been able to make a right turn to buy a 3.6 or even a 3.7?
RE: MGIII active crossover? - Skeepowder 19:25:04 08/14/16 (0)
I am posting my speaker rebuild on AK.
http://audiokarma.org/forums/index.php?threads/magnepan-mgiii-total-rebuild.727937/page-2#post-9854062
Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
RE: MGIII active crossover? - Skeepowder1@aol.com 07:08:47 08/04/16 (1)
Thanks again,
I found the MGIII manual on line and it has a section covering bi-amping with these recommendations:

Set the crossover to the following points and slopes:
Low Pass: -3db at 300 Hz at 18db per octave
High pass: -3db at 800 Hz at 6 db per octave

Then it goes on to say that the effective crossover is approximately 500 HZ.

Neo, do I want to set the XO frequency at 380 or 500 Hz.
And will this active crossover be as good as the OEM?
Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
- RE: MGIII active crossover? - neolith 09:25:54 08/04/16 (0)
  I would go for the lower value (300 Hz). Again remember these recommendations are approximate and were setup for the available active crossover units when the III came out (over 30 years ago). OTOH they should work satisfactorily and you will be shocked at the improvement with active biamping.
  While I can understand your desire to use the XM-9 (Marchand makes great products), we have moved into the 21st century and several inmates have gone to using the mini-DSP which is reasonably priced and gives you incredible options and controls. Perhaps some others can post their opinions and experience with these products.
  
  I married the perfect woman. The downside is everything that goes wrong is my fault.
RE: MGIII active crossover? - Satie 18:38:59 08/03/16 (23)
Neo has you covered and his suggestions should get you there.

I would just add that a 3rd order symmetrical bass-mid XO is probably doable in the XM9 and would likely work better than an LR4. Where magnepan uses a 1st order HP filter it is actually joining with the 2nd order rolloff of the driver to form a net 3rd order crossover. So doing a 3rd order symmetrical should work more like the original alignment than LR4.. Ask Phil for 3rd order boards - 400hz seems as good an approximation as any.
.
- RE: MGIII active crossover? - Skeepowder1@aol.com 19:58:36 08/03/16 (22)
  Thanks guys. I expect to hear from Phil tomorrow and I'll let you know. I'm also going to take the Mac in tomorrow and have some lamps replaced and give it a checkup. Unfortunately the rebuilding the Maggies part will probably take a month. Damn, stuck with my ADS. LOL
  Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
  - RE: MGIII active crossover? - Satie 16:34:12 08/04/16 (21)
    Since you found the effective XO as 500hz according to magnepan then you should set your symmetrical 3rd order there and are likely to get the best results that way.
    
    The other option is to just follow magnepan's biamp directions and just use the XM9 as a low pass filter and use a 1st order line level which simply amounts to a series capacitor calculated according to the mid/tweeter amp input impedance.
    - RE: MGIII active crossover? - Skeepowder1@aol.com 18:08:46 08/04/16 (20)
      Magnepan says that at 500 Hz the low and the mid/highs power usage are nearly the same so that should work out with my amp. I'm not married to that but it does make a point.
      I've started disassembling the Maggies. I found lots of threads on repairing the ribbons but not one on actually removing them. I took the screws out and now it looks like I need to unsolder them. Then they just lift out?
      Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
      - RE: MGIII active crossover? - Satie 20:28:51 08/04/16 (18)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder1@aol.com on August 04, 2016 at 18:08:46
        
        Are you talking about the ribbon proper or the planar drivers?
        
        The ribbon driver screws out and then you disconnect the wires - usually they have tabs. a few report having to desolder. Are you going to repair the ribbon yourself? Do you have magnepan's ribbon kit with the spray on rubber damping tabs?
        
        RE: MGIII active crossover? - Skeepowder 07:00:37 08/05/16 (17)
        
        In Reply to: RE: MGIII active crossover? posted by Satie on August 04, 2016 at 20:28:51
        
        I'll replace the entire ribbon assembly if needed. This one is soldered. I'm going to test it after I get it out but even then I may just get 2 new ones. The plan is to strip both speakers this weekend and order parts on Monday.
        
        I'm going to refinish the oak trim also so just about everything will be brand new.
        
        One of the issues that led me to biamping is the Mac 7106. It puts out 100 high current watts into 8 ohms or 150 into 4 ohms but if bridged then the speakers must be 8 ohms. By biamping the Maggies I will be applying up to 300 watts to each speaker. I'm not sure what I will do with the other 2 channels.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: MGIII active crossover? - Norman M 08:12:30 08/05/16 (16)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 05, 2016 at 07:00:37
        
        "I'm not sure what I will do with the other 2 channels."
        
        Use them to drive a pair of Magnepan DWM bass panels. It's been reported that even 20.7 owners benefit from them and enjoy their addition.
        
        RE: MGIII active crossover? - Skeepowder 15:00:18 08/05/16 (15)
        
        In Reply to: RE: MGIII active crossover? posted by Norman M on August 05, 2016 at 08:12:30
        
        Thanks again guys. The Mac is at the shop. The tech says the MC7106 are nearly bullet proof except for the lamps. He also says that I don't have to use all channels. I can let the 2 sit idle. Thanks for the tip on the Maggie base units but that's another $800. And I have to get good speaker wires still. I'm leaning toward the Supra Rondo 4X4 on ebay. Made in Sweden, 4mm which is about 11 gauge and a 4 conductor. I don't know about the ends, bare wire or what?
        Getting back to the Marchand....I would really like to use it, I have $225 into it already and I hope it is at least as good as OEM. It is a 4th order design. I have another email to Phil about 3rd order so we'll see.
        Before I'm done with this project I will have spent $2500+!
        One other thing I would like to pick up is a good CD player. I have an old Philips from the 80s or 90s. I hope to improve the sound of the system a bit there. There is no record player and no records but that's another thread.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: MGIII active crossover? - Satie 04:09:25 08/06/16 (14)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 05, 2016 at 15:00:18
        
        You can also triamp if you have extra amplification channels already. Another forum member and I did lots of experimentation on moving the mid/tweeter XO to first order on the 3a and the 3.3. Most of it offline. Also Neo has worked out how to copy the stock slopes into line level passive once you have moved out the tough portion - which is the 3rd order low pass for the bass to mid/tweeter. That portion has to be active XO.
        
        As I pointed out before, you can biamp using the XM9 with a 3rd order board to do the bass LP with magnepan's recommendation and use a passive high pass (just a capacitor in series with your mid/tweet amp's input) for the midtweeter.
        '
        
        RE: MGIII active crossover? - Skeepowder 16:41:36 08/06/16 (13)
        
        In Reply to: RE: MGIII active crossover? posted by Satie on August 06, 2016 at 04:09:25
        
        I considered tri-amp which makes lots of sense with the 6 channel amp. I read Andy's post on MUG on bi and tri XOs. It seems like I bought the wrong XO with it being 4th order and all. I'll explore the others and the options that were recommended by you and others especially for tri-amping.
        But now I have big news.....
        I stripped one speaker. The ribbon tweeter was soldered in. I had to buy a soldering iron to get it out. I knew I would need one anyway for this project. BTW I had 2 years of electronics in high school but that was when dinosaurs ruled the earth. Under the ribbon are a s#*tload of staples into the sock, I counted 46 on one side of the cutout times 2 for the other side plus another 50 or so on the bottom. I hammered a small crappy screwdriver with a slightly bent tip under the fabric and staple and popped it up some. I did one side this way then pulled all the staples with the end of my Klein wire strippers and repeated for the other side. First thing I noticed were numerous breaks in the mid wire section. I tested the bass and mid and got an open circuit on each. I couldn't see a break in the bass section although it had those typical corrosion spots that others had written about. The worst were along the outside edge. I took the crappy screwdriver and gently scraped those suspect areas and the 3rd one just broke away. It was hard to tell with the corrosion on top but the wire had totally dissolved. Just for fun I was breaking the mid wire at those bad spots by barely touching it. The ribbon tweeter tested good but I'll probably just replace it so I will have all new speakers.
        Except for that mid/high internal crossover which brings us back to tri-amping. It seems that I can get an active 3way crossover that will do what I want for under $300 and will sound better than the OEM passive units? I would like something plug and play. I'll have enough to do just rebuilding the speakers and modifying them for the tri-amp setup.
        I took pics of the desockifying and could post them if anyone is interested.
        
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        Edits: 08/06/16 08/06/16
        
        RE: MGIII active crossover? - Satie 04:41:26 08/08/16 (12)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 06, 2016 at 16:41:36
        
        Your heart really sinks when you do that exercise and find your drivers are literally crumbling.
        
        Are you doing the driver restoration yourself or sending it off to magnepan?
        
        RE: MGIII active crossover? - Skeepowder 09:26:42 08/08/16 (11)
        
        In Reply to: RE: MGIII active crossover? posted by Satie on August 08, 2016 at 04:41:26
        
        I ordered the parts from Magnepan today. The tweeters, bass/mid rebuild kit and socks comes to $433 including shipping. The price if they do it is $750 to $1000 per pair including shipping. Because I am now going to tri-amp I thought it wouldn't be feasible for them to do it. I'll have to bipass the internal XO and mount 3 sets of speaker connection terminals on the outside. That'll be fun. I have another thread on AK on this, too.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: MGIII active crossover? - Satie 09:32:46 08/08/16 (10)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 08, 2016 at 09:26:42
        
        Why not parallel post references to your AK posts here on the MUG as you go along. I am sure it would be more interesting to folks here,
        
        RE: MGIII active crossover? - Skeepowder 19:04:50 08/08/16 (9)
        
        In Reply to: RE: MGIII active crossover? posted by Satie on August 08, 2016 at 09:32:46
        
        It is hard finding crossovers for the right price. This outfit has a few:
        http://www.audioproz.com/AP.php?Prod=Crossovers
        Many are professional and mono but there are a few that might work. Could some of you please take a look and see what you think? I am looking for a 3 way now(3rd order?) because I have decided to tri-amp. I am trying to do this for less than $300.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        Edits: 08/08/16
        
        RE: MGIII active crossover? - Satie 22:00:51 08/08/16 (1)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 08, 2016 at 19:04:50
        
        You should start with a biamp project at this point both for budget reasons and since it is where most of the benefit happens. From biamp to triamp the benefit is much smaller.
        
        If the Ashly SC-77 is the 18 db 3rd order version (call them and ask) then that will be your starting point and you can at least use it permanently for the bass low pass. The mid HP would be a 1st order passive filer - just a capacitor in series to the input of the mid amp..
        
        Some of the Furmans are 18db units.
        
        If you are not big into analog, go with the digital option with mini DSP - preferably the HD variant.
        
        RE: MGIII active crossover? - BDP24 01:09:10 08/09/16 (0)
        
        In Reply to: RE: MGIII active crossover? posted by Satie on August 08, 2016 at 22:00:51
        
        The old Dahlquist DQ-LP1 has an active 18dB/octave LP section (along with 6dB passive HP).
        
        RE: That link to the XOs ... - andyr 20:35:11 08/08/16 (6)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder on August 08, 2016 at 19:04:50
        
        I looked at that list of XOs at the link you provided - most of them are not "fit for (your) purpose", IMO.
        
        My recommendation - like others here - is to go for a digital XO. I recently replaced the 3-way analogue active XOs that I'd been using with my IIIas (and then my 'Frankenpans') for 15 years with a miniDSP 10x10Hd. This is more than you want to spend - but you could get stereo 3-way XOs by buying a pair of 2x4 units ($105 each) or, better, the new 2x4 Hd units ($205 each).
        
        I'd happily give you my old analogue active XOs - which are set up for IIIas ... except that they are not 'plug-n-play'! :-(( You would need to get cases, wiring, power transformers etc., to make them work. Whereas with the miniDSP units, all you need to do is learn how to program the miniDSP software on your PC.
        
        Good luck,
        
        Andy
        
        PS: And good luck with the re-wiring - it is not something I would ever contemplate (whereas the electronics side in NP at all!)
        
        RE: That link to the XOs ... - Skeepowder 08:33:08 08/09/16 (5)
        
        In Reply to: RE: That link to the XOs ... posted by andyr on August 08, 2016 at 20:35:11
        
        Andy, I read your post on MUG about active 3 way so that's why I started down this path. Those miniDSPs are interesting but super techie. I was hoping for easier. LOL. Not ruling them out though.
        Satie,I was wondering about the feasibility of putting in a 2way/3way switch on the back so I can have it both ways.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: That link to the XOs ... - Skeepowder 08:55:21 08/11/16 (4)
        
        In Reply to: RE: That link to the XOs ... posted by Skeepowder on August 09, 2016 at 08:33:08
        
        I called the outfit on the Ashley and Furman. That guy talked a mile a minute and wouldn't let me say anything. He was really pushing me to hire him as an audio consultant and kept saying he would make amp recommendations despite the fact that I told him that I already had the Mac. I don't want to deal with him so that's that. That gear is all XLR anyway so that's just another complication.
        Still searching for the decent home unit with RCAs so I can just hook it up and turn it on. The miniDSP just looks complicated but I may have to go there if nothing else comes up.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: That link to the XOs ... - Satie 16:09:13 08/12/16 (3)
        
        In Reply to: RE: That link to the XOs ... posted by Skeepowder on August 11, 2016 at 08:55:21
        
        Don't worry about the RCA inputs. TRS adapters are fairly cheap and XLR adapters cost about double that.
        
        The 2 way 3way switch would not be enough since biamping would have you keep internal components while triamping would not. so would require different paths inside the speaker for each setup. The gain from going from biamp to triamp is less cost effective so I would leave that for a second stage upgrade down the road.
        
        RE: That link to the XOs ... - Skeepowder 16:59:17 08/12/16 (2)
        
        In Reply to: RE: That link to the XOs ... posted by Satie on August 12, 2016 at 16:09:13
        
        I hear you Satie on the 2 way vs 3 way setup. But dagnabbit I got a 6 channel amp which just tilts the whole argument toward 3 way and with 2 way those extra 2 channels are just wasting away (oh dear). And I need a crossover so it might as well be 3 way. BTW I just got that amp back from the shop and it's close to perfect. And I sold my boat yesterday and there is just a little extra cash.
        If you were in my shoes would you go for 3 way?
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
        
        RE: That link to the XOs ... - Satie 06:46:56 08/13/16 (1)
        
        In Reply to: RE: That link to the XOs ... posted by Skeepowder on August 12, 2016 at 16:59:17
        
        Triamping the 3A requires particular crossover alignment. The stock alignment is not reproducible for triamping with a commercial analog crossover. You would need to either rework the XO into one of the simpler schemes that have been worked out for it for passive line level. Or have a flexible crossover such as the XM44 or the First Watt B4, or one similar to AndyR's custom DIY job. The best choice among these for an experienced DIY electronics builder is the kind of XO AndyR built. But with power supplies and box it adds up.
        If you go for the triamping with the simplified mid and tweeter passive line level filters then a 3rd order Ashly or Furman piece will provide you with a good bass low pass filter.
        
        If you go for reproducing the mid tweeter XO in the original slopes and elbow frequencies then you would need a real active stage for that since they are 2nd and 3rd order and not textbook slopes. You can get that done with a multichannel 5.1 AV pre processor as Computerman did on this forum. That would provide all the gain channels you need and buffering and individual channel level adjustments. With that basic component you can do any crossover alignment up to 2nd order with passive components.
        
        But the complexity gets really bad. So my suggestion is to wait till you have the budget for a First Watt B4 crossover (it is 2 way) and add the 3rd order commercial piece for bass LP and that would allow you to triamp precisely as you can. But that will definitely blow up your budget.
        
        For the passive 1st order mid tweeter section in passive line level, Davey from the UK has worked out a crossover alignment that can be implemented easily with just the commercial 3rd order for bass LP and passive components.
        
        The DSP crossover option - like minidsp is an order of magnitude more flexible and has room correction options. If you are playing predominantly digital sources then you have nothing to lose using the DSP. if you have the budget then a DEQX unit would be the way to go.
        
        RE: That link to the XOs ... - Skeepowder 08:19:12 08/13/16 (0)
        
        In Reply to: RE: That link to the XOs ... posted by Satie on August 13, 2016 at 06:46:56
        
        I've just about made the decision on the miniDSP 4x10 for $500. The others are too expensive or not as configurable. I've read about half of the manual. I can use it 2 or 3 way and it seems like it will do all the needed slopes and configurations. I don't have any records or tapes so there is no analog input but it will do both if my gear changes in the future. And it has RCAs. The XLRs were just one more issue and expense on the others. The computer setup on the mini DSP is near the limits of my abilities but I 'll just have to adapt.
        Thanks guys.
        Bobber
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
      - RE: MGIII active crossover? - Skeepowder1@aol.com 18:41:02 08/04/16 (0)
        
        In Reply to: RE: MGIII active crossover? posted by Skeepowder1@aol.com on August 04, 2016 at 18:08:46
        
        Those ribbons were stuck just a bit. I got the one out.
        Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
MGIII active crossover? - neolith 14:18:17 08/03/16 (2)
You will need four (4) modules not one to get the Marchand XM-44 up and running. You need a woofer LP (low pass) and a mid HP (high pass) for each of the two stereo channels - cost is $36 plus shipping.
Understand that the "recommendation" from Magnepan is only an approximation and was done because most commercial crossovers are not very flexible and are limited in their ability. The Marchand has the ability to be customized to just about any order, slope (Q value) and frequency and thus can be designed to match almost exactly the OEM crossover.
Here is a link to my spreadsheet which will simulates the OEM crossover. Ignore the mid LP and tweeter HP as you will not be triamping. The notation for the caps and resistors may differ from that used by Marchand but Phil will have no trouble with it. The spreadsheet is written for LibreCalc (part of the LibreOffice Suite) which is available for free. I do not support Microsoft.
If you have questions, please feel free to email me.

I married the perfect woman. The downside is everything that goes wrong is my fault.
- Maggies Go Active Spreadsheet (Open in New Window)
Edits: 08/03/16 08/03/16
- RE: MGIII active crossover? - Skeepowder1@aol.com 15:36:48 08/03/16 (1)
  Thanks Neo, I have the Marchand XM9. I don't know if that's the same as yours regarding the XO modules. I looked at your spreadsheet and it's more involved than I want to do but thanks anyway. I'm just trying to find the crossover frequencies so I can buy the modules. I can't find a MGIII manual but I find the MGIIIa. Are they the same for the XOs? I have contacted Marchand to see if he has a recommendation but haven't heard back yet. Tomorrow I'll call Magnepan.
  Mac MC7106, Maggie MG111, ADS 810 & 780, Pioneer SC-1522, Carver M.0.5T, Dahlquist 903, Velodyne, Infinity
  - RE: MGIII active crossover? - neolith 04:22:47 08/04/16 (0)
    The III uses a 1st order Mid HP filter and the IIIa uses a 2nd order filter. A simplified approach might be to use a 3rd order Woofer LP at 270 Hz and a Mid HP 1st order at 800 hz. The crossover point for the III is 380 Hz.
    I beleive the XM-9 uses a variable state configuration rather than Sallen-Key. What this means is that the crossover is always symmetric and for the XM-9 this is 4th order.My experience with symmetric 4th order LR on the IIIa's was less satisfying than simulating the OEM. Also you will only need two boards for a state variableas as each board covers the LP and HP filter -- set each module at 380 Hz. Also you will have to do a little wiring change in order to account for the inverse polarity of the OEM vs the normal polarity of the LR. The easiest approach is to swap the input wires (+ and -) coming into the woofer.
    
    I married the perfect woman. The downside is everything that goes wrong is my fault.

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