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Way down below is the schematic - dotted lines are the jumpersHF panel
10 mfd Solen PA MKP FC ? % 250v
6.8 mfd Solen PA MKP FC ? % 250v
5.1 mfd Solen PA MKP FC ? % 250v
0,1 mfd Electrocube 410D1B104K 10% 100v
This group conected together lead twisted on leadLF Panel
25 mfd Electrocube 230B1B256K 10% 100v
Inductor looks like a Madisound Sledgehammer square coil with laminated steel coreConnecting Wire (multistrand) diameter looks about 1.2 mm
Components fastened to mdf board with nylon cable straps
Connections all made to solder tabs which are riveted to mdf
Banana sockets look sub Rat Shack quality
Fuse Holder looks extremely cheap with riveted connections
Connections on driver Panels - male tab (tinned) abt 3.5 mm
Connector on wire to panels - female tab gripper (tinned)Components splattered with black spray paint !
It is a revelation that such sweet sounds comes from these bits.
Food for thought
1.Replace caps with Hoveland or others
2.have a pcb made to mount the caps (copper traces better than connecting wire ?)
3.Install 4 decent terminals per speaker, Vampire, Cardas etc
4. Eliminate fuse
5. Probably not a good idea to change the material of the gripper as different metal
corrosion might result6. Forget the crossover and bi-amp with active crossover feeding power amps!
Suggestions Welcome
The inductance of the steel laminate cored coil is apparantly 3.3 mhMadisounds Sledgehamer coil with this inductance has a DCR of 0.185 ohms and costs $ 10.25
The Solo 12 gauge foil inductor supplied by Ric [EVS] to a Maggie owner has a DCR of 0.37 ohms and costs $ 53
Alpha Core 12 ga foil has DCR 0.268 ohms costs $44.30
Solen 12 ga Hepa litz has DCR 0.45 ohms costs $54.65
Solen 12 ga Hex Lay has DCR 0.32 ohms costs $ 45.50Hands down to Magnepan for price / performance !
that's a tad large for a 1.2kHz XO on a 4ohm driver. A 1st-order would mean a 0.53mH. A 2nd-order,Linkwitz-Riley would be ... 1.06mH & 16.6uF
Bessel would be ........... 0.92mH & 19.0uF
Butterworth would be ...... 0.75mH & 23.4uF
Bessel would be ........... 0.53mH & 33.2uFdid you measure the choke?
With a 600Hz XO frequency want are the inductance values for the different types of filters ?
you will notice that the 600Hz XO on a 4ohm driver is twice that of prior octave higher 1.2kHz. That's because the frequency is halved. It's the exact same multiple.Linkwitz-Riley would be ... 2.12mH & 66.3uF
Bessel would be ........... 1.84mH & 38.0uF
Butterworth would be ...... 1.50mH & 46.9uF
Chebychev would be ........ 1.06mH & 33.2uFhope this helps...
According to the schematic from Magnepan, I have been told that the inductance is 3.5 mhWith the values of 22 mfd total on the HF and 3.5mh with 25mfd bypass on the LF, and 4 ohm panel impedance, what kind of crossver and what slopes is that ?
someone wants to know how to get the numbers. These are the equqtions...
1
f == ----------------------
2 * Pi * Sqrt[ C * L ]
Sqrt[ L / C ]
Q == -------------
Z
keep in mind
Q < 0.5 ... means overdamped transients & slow XO
Q > 0.5 ... means underdamped transients & fast XO
The 2nd-order LowPass is dynamicly-overdamped which means it can't peak nor ring. It's a real slow roll-off. It may seem 1st-order in the beginning. Hope this helps...If this helps explain the XO's Q factor ....
Linkwitz-Riley would be ... Q = 0.5
Bessel would be ........... Q = 0.57735
Butterworth would be ...... Q = 0.70711
Chebychev would be ........ Q = 1.0
The value of the coil is .75 mH. a thicker gauge air core is suggested, but then what do I know. Thanks Ed for your post. The MMG's are just a small 1.6Regards to all..
Tazsmonn
Minneapolis
Very good
Very cool.
Ed,
I am going to post this info on what my friend did to his 1.6s on my website, but I might as well tell you here as well. I told him what to do and I bought him the parts. He replaced the caps with a combo of SCR/Axons (a 20uf and a 5.6uf for the bass and a 20uf and a 2.2 for the tweeter)all bypassed by .22uf Infinicap Signatures "D". All the caps were installed with the proper polarity (outer foil connected to ground or output). I tested the caps for him and marked the polarity. You can test polarity (outside foil) by putting a 1K sine or square wave (10 volts peak to peak) into the cap from a signal generator (the hot of the signal generator goes into one lead of the cap and the ground of the signal generator goes to the other cap lead, and then you reverse leads and see how much signal is tranfered to a scope probe laying on the outside of the cap. The side with the most voltage is the outside foil. The coil was changed to a 12 gauge Solo. It is so big it has to hang outside the speaker. My friend said the better coil made a huge difference. He eliminated the fuses and the binding posts and all connections that were not completely direct. In other words, he soldered his bi-wired speaker wires right to the x-over parts and then used Harmonic Tech wire to wire the components directly to the panels. No circuit boards, extra connections or anything. He also left the grill cloth off. Happy tweaking.Ric Schultz
EVS
I do the same thing with my Goertz 12ga CFAC's. I figure if it works for caps it should work for chokes. That is ... the outside faces the amp & the inside faces the driver. The only difference is that a choke uses the same conductor. I figure the inductance will choke out the RF.are the InfiniCaps non-L? I found them to maintain the linearility best thus far.
What size Solo choke did you use?
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