Blown Tweeter & midrange fuses Magnepan 3.6r

Just cranked up a pair of 3.7i with magtech mono blocks (1000w per channel). at 0db, all the fuses blew.

Hey Sangel,
I have Magnepan 3.6s also. Had them about 3 years. I owned 2.5s before these and had the 2.5s about 12 years. I occasionally would blow a fuse with the 2.5s a few years ago. I am now using Krell ksa 250s biamped and have never blown the fuses on the 3.6s. I too like to listen to music at loud volumes. Sometimes hard rock like Korn, Foo Fighters, etc and it frustrates me when I remember my Cerwin Vega d9s from high school that had an spl of max 125. Of course, they did not sound as good as a magnepan or a Martin Logan. I am wondering if the Martin Logans play louder than maggies without sounding harsh??

HELLO,

PLEASE LET ME KNOW THE RIGHT TYPE (AGC, ACG, ETC) OF FUSES REGARDING MAGNEPAN 3.6.
ALSO, IN THE MANUAL IS WRITTEN THAT THE FUSE FOR LOW IS 4 AMP BUT ON THE BACK OF THE SPEAKERS SHOWS 5 AMPS.
THEN WHICH IS CORRECTED!!

THANKS IN ADVANCE

ALL THE BEST

SANGEL

Sgr:I too had MGIIIa's with 500watts a speaker and run into fuse problems with Techno or movies at that finite limit of volumn and cleaness but they were magically fast up to that point. I considered going with the MG20.1's and was concerned as sometime I can listen to thing louder than I should, and I couldn't really fit the 20.1's in the small space I had at the time. I found the Wilson Watt Puppy 7's capable of that precision quickness of the Mag's ribbon but with the Dynamics I craved (plus that whole 20-30hz bass my mags never really had).

The Magnepan 3.6's are still a bargain for their performance, another option is to look at using a fast sub (Rel) to cut out the 20-30hz bass and let the speakers relax a little more, but they will still beg to go louder because they play so clean.

The problem with these speakers is that they play extremely clean with no sign of breakup. They really just start sounding good (to me) at 95db as I recall. At somewhere around that point, most amps run out of headroom, or perhaps there is a finite point to the amount of current they'll take. And then, zap goes the fuses and the tweeter (which makes little sense to me since the fuse should protect the tweeter from getting too much current whether the amp is clipping or not).
Don't get me wrong, I love the sound of these speakers and even sold them for an audio store twenty years ago, but to my mind, the 3.6s must have a flaw, since I owned the MG-IIIs for 15 years and never blew out a tweeter with the same equipment.
Magnepan was mistified and could not help me solve the problem, so I sold the speakers and bought a pair of Revel Salons.
There are times I'm tempted to try the Maggies again, (I loved the Typani 4s) but will stay away until Magnepan addresses these problems. With the high end equipment that I've owned (even biamping them) those tweets and fuses should not be a concern.
My advise is to look elsewhere for speakers as you will not get the volume you appear to like without many heartaches.

400+ watts into 4 ohm, pull the speakers out into the room. If you are watching movies this will happen even more so with this few watts.

Something isn't right about this picture. I've had over a dozen amps with my 3.6's and never blew a midrange fuse, despite playing quite loud (85db with 95db peaks measured on a RS SPL meter)and despite having a room over twice the size as yours. I suspect your definition of 'somewhat moderate' is compatible with my 'very loud'. You need to get an spl before you do anything else, measure what you think is moderate and go from there. You may find these speakers are not for you, they are not really designed for very high spl's. Incidentally, I used a Krell FPB 200 with 400w into 4 ohms and never blew a fuse in the 3.6

I use a spectron Musician II amp that puts out 650 watts per channel. I can still blow fuses in my 3.6's at high volume intervals. I can only crank up to about eleven o'clock on the volume without having to replace fuses. i believe that excesive volume on any amp with cause your Maggies to blow off. I have found that using an amp with more clean power doesn't elliminate the problem that you've outlined here..........

" open floor plan " this means your room is even larger than 15'x20'. Another thing to know is that your type of speaker does not sound as loud as you guess it is...a spl meter will show you this.

I don't know your Krell amp but I do own a couple of Krell's. My baby Krell (Kav-500) is rated in the same ball-park as yours at 240 watts/4 ohms. The power supply in these little Krells is not enough for your speakers. I have tried mine with my 4 0hm. Apogee Duetta Signatures, while it will play them and sounds very good...high spl's cause it to run out of steam very quickly.

I use a Krell Ksa-250 with my Apogees in my 25'x23' room, it has over 4 times more reserve for those loud moments (which don't sound that loud).

Dave

Hello,

I have had similar experiences with fuses blown with 3.5's. With an ARC VT130 amp, 110wpc, this amp clipped just as the volume started to get very loud but it was a very soft clipping and I think because of this, the fuses failed only a couple times. With ARC Classic 150's (150w monos), these amps have a protection circuit to shutdown the amp when it clips, so this happened frequently rather than blowing fuses. Then I tried a Counterpoint NPS400 (400w into 4 ohms) and only a couple times did tweeter fuses ever blow; this amp was a great match for the Maggies, not just musically, but also in power delivery. And currently I use Wolcott Presence amps (275w monos) which are an outstanding match but when the volume gets loud, mid and tweeter fuses fail. The Wolcotts have a great midrange presense and bloom on vocals and for loud passages, they can run out of steam and clip, not as soft as the ARC VT130. I can only imagine how incredible a pair of Wolcotts with double the power would be!

As for low power amps, I tried a 40wpc stereo tube amp and in no time, the fuses were failing because the amps were clipping. There is just no way 40w is going to work with the Maggie 3.x speakers. I am sure biamping these speakers would reduce the power demands here significantly.

John

I think 250 watts per channel may not be adequate for your room size and listening levels. Maybe you should look at 500+ watt amps.

Anyone who is driving 3.6's in a "good size room" with 40 Watts per channel must be clipping the amps like crazy. My guess is that they're tube monoblocks and that the owners like a lot of second harmonic distortion... I don't think a 40 Wpc solid-state amp would fail to blow the Maggy's fuses at even moderate levels in a large room.

BTW, it's not at all good for the amp or speakers to keep blowing fuses like that!!!