Magnepan 1.6 vs Magnepan MG-1

Gmood1...I have been through the experience of burning up tweeter wires on my old original MG II, so I am happy to have the peace of mind afforded by the fuse.

I do use the "tweeter attenuator" which is the same thing as the "padding resistor" that other loudspeaker designs hide away in the crossover network. I like the Magnepan approach of letting you select this resistor value. If you like zero ohms, that's fine. I am using one ohm, but I often turn down the treble tone control by 2 dB, so I may experiment with 1.5 ohms.

Last week I assembled a new set of speakers for my rear channels, Odens, from Madisound. My old Dynaudios, with 5" MTM drivers are excellent, but just couldn't keep up with three MG1.6 plus subwoofers in the front. I sprung for the "premium" version of the crossover, and was impressed. Accordingly I have decided to treat the Maggies to a top-of-the-line crossover, and have just ordered $530 worth of stuff to do the deed on three speakers.

Eldartford... I couldn't help myself ..had to remove the fuses and bypass the resistor. The 2.5Rs sound like a totally different speaker.Someone needs to design a fuse that doesn't diminish the sound quality.Until then I guess I will be riding the edge of tweeter destruction. Are you going to make outboard crossovers or just replace components on the panel? May try this just not sure where to start thou. Might be easier for me to pack them up and send them to you ! HEh hee

Gmood1...After some study I have settled on the following design.

I will retain (at least for now) the original terminals and fuse holder.

I will remove all the original crossover components.
In the space of the original crossover, I will install the tweeter capacitors: three 7mfd musicaps = 21 mfd. Thus the tweeter will always be connected through its capacitor.

The woofer terminals will be connected directly to the woofer, requiring that the inductor be outboard.

The outboard inductor will be "wired into" the woofer's (biwire) speaker cable. No extra terminals involved.

I have chosen to use 3mH instead of 3.5mH. Note that the tweeter capacitor of 21mfd is changed from the original 22 mfd. This will shift the crossover frequency up slightly, and reduce the gap between tweeter and woofer that causes a dip in the overall frequency response. I am quite sure that the woofer can play a few Hz higher in my application where the Maggies are crossed over to a subwoofer at 90 Hz. The inductor will be a 10AWG air coil from Madisound. (I will try it this way, and tweek as necessary).

By the way, aren't the 2.5R three way? The MG1.6 are 2 way with a very simple crossover which makes upgrade particularly attractive.

Eldartford..no the 2.5R is a two way design. Here's a general spec sheet of the differences in Magnepans former and current models.http://www.integracoustics.com/MUG/MUG/articles/speakers.html

Please keep me informed of what components you find that work the best in the crossover. It would be nice if there was a guide book with different types of upgrades and what each one will do to change the sound in the magnepans. But I understand it will be trial and error.A guide book may save a little money in parts thou.

Gmood1...That is an interesting summary of all the Maggies. I note that the crossover of the MG1.6 is given as 600Hz acoustic. From an electrical point of view, the woofer is 3dB down at 180 Hz and the tweeter is 3dB down at 1800 Hz. The crossover slopes are 12 dB for the woofer and 6 dB for the tweeter and both parts of the mylar screen are still driven in the range between the crossover break frequencies. The acoustic output is reportedly down by 4dB at 600 Hz, and tweeks have been developed to boost output at 600 Hz.

My revised inductor value will raise the woofer crossover to 215 Hz and the capacitor change will raise the tweeter crossover to 1900 Hz. These are small changes (and they save a few $) but I really think that the resulting crossover is better optimzed for use with a subwoofer, where the woofer panel is not trying to pump out 50 Hz.