Tweaking the Magnepan 1.7s


Looking to tap the Audiogon crowd to come up with inexpensive tweaks for my new Magnepan 1.7s. Here is what is planned so far:

Have room treatments. I am a bigger fan of sound absorption than sound dispursement. I have four 2' x 4' x 2" sound absorption panels that sit on each side of my stereo shelving unit between my speakers. Does a great job of removing the reflections off of my electronics.

Having Magnepans for 30+ years, I do like to deaden the front wall behind the speakers a little bit. From hanging an oriental rug to curtains or whatever. Will be trying out some of these ideas with my new location.

Mye stands. I am waiting for my bank account to grow a bit before I go for these. I believe Mye has the new updates for the 1.7s (although, I can't see any difference between the 1.7s and my old 1.6s).

I want to bypass the fuse and that stupid metal jumper with the least disruption of the speaker itself. Anyone remove the back panel and replace with better speaker connects? If so, what do you recommend? How about wiring tips - anything I should be know before I start the project?

Debating on using a 1 ohm resistor to tame the high end. Any suggestions for high quality 1 ohm resistors?

Anything I am missing?

Sound notes: full description of my experience with Magnepan 1.7s and the electronics I am using in other Audiogon threads, just search for ronwills.
ronwills
The Mye stand isn't quite an option for me as I live in HK. They charge $7xx just for SHIPPING alone to HK...
The reluctance people show about using a resistor for the tweeter is amusing. In general, tweeters are more sensitive than woofers and all crossover networks include a "tweeter padding resistor" to achieve balance. Because Magnepan makes its own tweeter and woofer they are almost balanced without a resistor. Magnepan gives the user the choice of value...1.0 to 1.5 ohms is typical. Many crossovers run 2.5 to 3.5 ohms.
Good for you, Josh.

Try 'em all 4 ways for that matter....tweeter in / out and Mylar front/back.

I wonder if Magnepan started shipping with the tweeter resistor at about the same time as they flipped 'em to pole piece back?

I've tried absolute phase swapping and hear little difference on MOST material.
My sub, however, appreciated the phase switch being flipped after I rotated the panels.....Makes perfect sense.
I'm not sure when they started shipping the tweeter resistor. I confess I'm one of those who's reluctant to use it, because I don't like the shelf effect on the frequency response. This may not apply to the 1.7, I'm not even sure where it's wired/what the crossover points are! But it seems to me that some kind of adjustment is necessary in any wide dispersion speaker, since room acoustics are going to change the HF balance and not everyone has the option of tuning their listening room.
Josh358... The resistor "shelf effect" counteracts the shelf effect which exists when no resistor is used due to the greater sensitivity of the tweeter. The resistor is simply in series with the signal feed to the tweeter section of the crossover.

You don't have to use a resistor, and if you do you can pick the value. That's nice of Magnapan.
Has anyone tried using the Walker hi definition links
with the 1.7? I am planning on getting the new maggies
soon and have a set of links to use. other than the
difficulties with using spade to banana adapters, what
else could present a problem?
I have had my pair of 1.7's since about April. Owned MG1B's and MGIIIA's for a long time before, listened and liked the MG1.6's but not enough to pull out my wallet for the difference.
The 1.7's have that critical quality for bass realism, weight that is satisfying to a tuba player and low mid range tonal accuracy. The 1.7's on initial listen caused me the same reaction as the IIIA ribbon tweeter, a little bright so used the 1ohm resistor. Over a few months I realized the brightness was a source issue, that my Linn Genki and Oppo 971HD weren't handling the highs musically, into my DAC creating listening fatigue. I now use my PC with an HRT Music Streamer II USB DAC and Foobar2000 as a music player to feed a CJ PV10A and Musical Concepts modded Hafler. The 1 ohm resistor is out, just the stock jumper, sounds gorgeous with 24/96 tracks and the 20 bit HDCD RR recordings that DBPoweramp allows me to decode and rip.

As to tweaks to make your sound better
1) get idle cone speakers out of the room unless they are small. Idle cone speakers resonate and collapse sound stage... good Linn dealers can demonstrate.
2) consider the mye stands or any other like alternative the will brace top and bottom of the panel and tie solidly into the floor. A tall panel speaker like the MG 1.7 with foot stands producing music is like a car engine flopping around on broken motor mounts. It will damp/blur your transient peaks if you leave the panel free to move.

I don't recommend leaving out the fuses... it only takes 1 power hit to make your tweeters toast... been there. Fuses and jumper substitution doesn't have a science to it but won't break the piggy bank either.

Enjoy, if yours sound bright/fatiguing as mine did at first look very hard look at your source equipment
Davide256... Magnepan agrees with you that the brightness is a source issue. They say that because many popular speakers roll off highs recordings are mastered with boosted highs. They claim that the Maggie is flat without the resistor, but that the resistor makes them more compatable with the typical recording.
Has anyone experimented with resistors of a smaller value than the one that came with the 1.7? I find the stock resistors cutting just a tad too much...
Sure? Why not a pair of 1 1/2 ohm in parallel....or a pair of 1 ohm? Many practical combinations exist to put less than 1ohm in series w/the tweeter.

Just think about the resistor in this fashion:
If the driver is 4 ohms, and you put 1 ohm in series with it, roughly 20% of the power will go away...as heat, while the driver gets less power and doesn't play as loud.
You could put 0.1ohm in series and still get an effect, though the 2%+ of power now being dissipated by the resistor may not make an audible difference.
Someone needs to come out with an adjustable resistor, audiophile quality, for use with the 1.7!
One thing you can do is get a wirewound rheostat and use it to adjust the tweeter level to your liking, then remove the rheostat, measure the resistance with an ohmeter, and buy high quality fixed resistors to match.
Is this kind of resistor good for audio purpose?
Vishay RWM8X450R475BO50E1
wirewound,vitreous enamel,12W,0.47 ohm
Josh,
Doesn't a wirewound rheostat have enough inductance to change things.....and not necessarily for the better?
Sure. The idea here is to use the rheostat to zero in on a figure, and then replace it with a non-inductive fixed resistor. I'm assuming that the series inductance won't make enough of a difference in the frequency response to render the results useless, but without running the numbers (or trying it) I can't be absolutely sure of that.

Wslam, a lot of people recommend the Duelund resistors. Whether they actually make an audible improvement over run-of-the-mill wirewounds, I don't know.
Yeah, Josh, I was being a stinker. The company I worked for and Vishay had a couple million dollar disagreement, so I'm not big on Vishay products.....

Now, about those awful jumpers.

The ones on my 1.6s are MAGNETIC, which as near as I can tell means steel.

I'm making replacements from 6ga copper wire, and whittled into shape.

First pair done and installed.

Does the 1.7 STILL use this jumper type? What have others done? Please don't suggest biwire....unless you can also tell me how to rid myself of those banana plugs, too.

sheesh.
How would one go about biwriing, or better yet, biamping 1.7s? I thought it was "not possible."

-Paul
I think that we have already talked about tweeters in and out and front to back.

You can change out the metal jumper. I replaced mine with a solid copper wire. I think that it makes the sound a little bit more detailed. Not sure how bid a deal that really is in my setup.

I pulled the back plates off and it looks like you cannot simply unscrew the wires like is possible on the 1.2's to bypass the fuse. I closed mine back up and decided that I would think about that before I messed with it.

The big thing is that I found a pair of Mye stands on Audiogon.

They make a noticeable sonic improvement. Everything is more tight. The bass has a little bit more weight. The sound in general is a bit more detailed. Overall, this makes the 1.7's sound more musical.

Having said that my local audio store has a set of Mark Levinson amps hooked up to Revel speakers (the $20K ones) That sound is better than my Krell and 1.7's (of course at a very steep price increase!).
People are saying you can't bi-wire the 1.7....this means NO jumpers, right?
That's why I asked.

If I had a look at the crossover schematic for the 1.7 it would be easier to decide if you could bi-wire and how much butchering you'd have to do.

Try the Revel's against the 20.1s and you may change your preference....and get to keep your Krells. Or maybe swap the Krells out for top Bryston or Pass....
I listened to the Revels again with a CD by the Jayhawks that I know quite well. I decided that the Revels are not that great after all. Thery definitely have the bass and weight but they do lack the last bit of detail and resoluton that I hear with my setup. On my setup I am able to hear separate harmonizing vocals that did not come through on the Revels.

I have an Audiospace CD player and the Revels were hooked up to a McIntosh CD player - do not know which one. Maybe that has some thing to do with it.
I have had my 1.7's for a month now. They were initially too bright, even in a heavy carpeted room, C-J amplification and with vinyl as a source. The cure, in order of impact:
1. 1 Ohm Pathaudio resistors (significantly better than both the supplied ones and the Mills).
2. Quantum SR20 fuses (inserted with the 20 in the upwards direction). Much better than the supplied fuses and, in my view, better than the Hi-Fi tuning fuses.
3. pointers under the speakers (have not tried speaker stands)

I'm in heaven! I no longer worry about break-up time or potentially expensive mods, I just enjoy the music.