Magnepan MG-20 attenuation & tips

[K-High-Fi]

Hello,

I never use attenuation before nor any idea about it, I know should perfome through insertion a non-inductive resistor, what i would like to know how attenuation look like? Is the one come with MG-20 accesserios that look gray and very small piece: width 2 inch, hight and depth half inch, and have two long solid thin metals about 1 and half inch long?

And any other tips for MG-20 to improve the sound?

Anyone care to answer,
Many thanks to all.

[JoeE SP9]

Adding the resistors to the tweeters will lower the tweeter level by a couple of dB. Will it be an improvement? Well, that depends on your room, your ears and other factors.

If you think the sound is too bright, lowering the tweeter level will be an improvement. With your room width your Maggy's are probably close to the side walls. Placing some sound absorbing panels at the first reflection points on the side walls may be what you need to do. This is a tweak that always helps.

If your floor is hardwood, tile or another reflective material, carpeting or strategically placed throw rugs would be very helpful. The first reflection point is most important

[K-High-Fi]

Thank you JoeE SP9 very for reply and helpful information's. I installed the attenuations and found the sound much better, in beginnings i was afraid because i don't know how they look but i figure out the small rectangular two piece.

Yes i will try some absorbents on the side walls, i know planer are critical about reflections but i will try a thin absorbents like curtains or cotton cloth. before i tried fabric all the sides wall but i lost micro dynamics and upper bass.

[Dawnrazor]

My 2 cents is that you might be better off ditching the attenuators and using rf chokes instead.

They are cheap enough to try and really work. The mag ribbons can act as radio antennas and rf can get back to the amp and create some brightness.

Here is some info from the guy who figured it out and implemented it on his mg20s:
http://db.audioasylum.com/mhtml/m.ht...rchtext%3D12e1

[JoeE SP9]

If you could post a basic diagram of your room with a description of the furnishings I could give more specific advice.
To find the first reflection points have another person move a mirror along a side wall while you are seated in the "sweet spot". When you can see the speaker on that side in the mirror you have found a first reflection point.
I have 2' x 4' x 3" DIY traps at the first reflection point on my side walls. There are more traps in the room including round bass traps.
Making your own traps is quite easy. Manly Stanley started a thread about his DIY room treatments. He proves that "acoustic treatment" doesn't have to mean agricultural design and utilitarian looks

His look better than mine. I'm quite jealous.

MS, you have shamed and inspired me. My spring project will be to follow your lead and make mine look better.

[K-High-Fi]

Thank you all for wonderful posts. Can i find these chokes online? And anybody try Cardas attenuators? I heard they improve the sound better.

Thanks to all.

[Dawnrazor]

Thank you all for wonderful posts. Can i find these chokes online? And anybody try Cardas attenuators? I heard they improve the sound better.

Thanks to all.

http://www.mouser.com/ProductDetail/...%252bOcg%3d%3d

[JoeE SP9]

Magnepan doesn't have the best responses where email is concerned. You'll get the best results by calling them on the phone. They are very friendly and quite helpful over the phone.

[K-High-Fi]

Thanks Feanor very much for the link, very helpful.

The resistor comes with MG-20 have: 10 watt and I think 5 % tolerance, is it ok if I use 12 watt with 1% tolerance?

Here is the information written in Magnepan resistor:
CP-10 Mexico 10 W
1 ohm 5% Dale 9636

Also, can I use below 1 ohm and above 2 ohms?

[JoeE SP9]

I would be careful about changing the wattage. It's possible that a resistor with too high a wattage could allow tweeter damage although going from 10 to 12 watts isn't a very large change. Replacing resistors is much cheaper than ribbon replacement. Using 1% resistors instead of 5% will give closer matching of their value. That's always a good thing.

Magnepan would probably approve closer tolerance resistors but not ones with a higher wattage rating.

Changing the value will change the tweeter level. A higher value, less treble and vice versa.

[K-High-Fi]

So is there any risk to the tweeter if i use 12 wattage ?

As for value, can I go up like to 3 ohms or more without any risk ?

[Feanor]

So is there any risk to the tweeter if i use 12 wattage ?

As for value, can I go up like to 3 ohms or more without any risk ?

I doubt that there is much additional risk from 12 watts vs. 10 watts -- a resistor will not protect your tweeter like a fuse in any case. If the problem was that you were sending too much power, the resistor would probably pass more than its rated maximum watts for long enough before failing to damage you tweeter.

You could go to 3 ohms resistance or virtually any value without harming your speaker.

[K-High-Fi]

May i ask if i want to put sound absorbing panels at the first reflection points on the side walls, what the most suitable materials or brand for MG-20 ?

Can I use curtains or normal fabric?

[JoeE SP9]

Sound absorbing panels are the same for any kind of speaker. Do a search for the thread Manley Stanley started here showing how he made his own panels. There are also plenty of DIY sound absorbing panel projects all over the web.

What makes sound absorbing panels work is the fiberglass behind the fabric. The fabric covers only need to be as acoustically transparent as possible. Curtains and/or normal fabric by itself aren't particularly effective.

[K-High-Fi]

Thank you JoeE SP9 and all for helpfull replies. I understand it all, I will look for absorbents. Thanks.

[JoeE SP9]

Look for sound transparent fabrics that are aesthetically pleasing. The fiberglass panel underneath is what matters.

Owens Corning fiberglass panels are what you need. See the link below. Build some simple frames to hold them. Wrap them in acoustically transparent fabric of your choice. Hang them in the appropriate spots. Voilà! Better sound immediately.

Amazon.com: Owens Corning 703 24"x48"x2" Fiberglass Boards - Pack of 6: Musical Instruments

[Big Dog RJ]

Please read your MG20 owner's manual carefully and then give Magnepan a call with all your questions!
Your owner's manual just about answers every question you have asked on this forum.

Just like the others said, you can call Magnepan and they will be happy to answer your call. I have personally spoken to a person named Steven in Techincal, he was very helpful. But he told me very abruptly "first read your owner's manual!" and that was about 16 years ago.

I hope it all goes well for you K, because the MG20 is a great speaker that requires proper placement and the ideal room for them to sound right. To me it sounds like you defenitely have a serious room problem... Again your owner's manual talks about this under sections -room placement, room treatment and room acoustics, plus ideal room size for MG20; I forget what page it was...

If you don't have any of these traits, then I suggest purchase a smaller pair of maggies such as the 1.7QR (fantastic magneplanar speaker) to me set up properly sounds far more coherent than the MG20). I have been using magneplanars for over 20 years since 1986, and only recently switched to Electrostatics.

Magnepan is a very well established company and will be happy to assist. However, they do prefer that you also seek assistance directly from your Magnepan dealer, they should also know a great deal about magneplanars.

Cheers mate, and have a good one.
RJ

[JoeE SP9]

Although I agree with just about everything Big Dog has written, it in no way diminishes the need for room treatment. Fixing the room acoustics is like getting a 50% better system for a couple of hundred dollars. This applies to every room and every system regardless of cost.

I went through three pairs of Magnepan's since 1976, (MG-1, MG-2A and MG-3.1) before switching to esl's.

[Big Dog RJ]

Yes Joe, I completely agree with room treatment.
Infat I just posted a longer coment about this, and for some reason it didn't go through.

Anyway, to cut a long story short, I had this experience with my very own Alexandria X-2's. The sound was crap, because my room was crap. I sent them off back to my overseas dealer who galdly found a new home for them with a surgeon. His room was very dedicated to Wilson type speakers since his previous system was a Infinity IRS V series, plus Apogee studio Grands. The chap also owned previously the Martin Logan Statements Evolution III series. He was extremely pleased with the X-2's and in his room they sounded absolutely stunning.

Now in my smaller room I get excellent levels of realism with the ML2.2's driving the Quad 2905's. In my opinion the room plays around nearly 80% of what your system is capable of. And if it is a high end system capable of revealing a remarkable soundstage, you MUST get your room sorted out.

I don't know what problem Mr. K is having, seems like something is not right here inspite of him have top notch gear from Krell driving MG20's. If he could send us a photo of his set up, I have a pretty good hunch of what the problem might be...

Cheers and have a good one.
RJ

[K-High-Fi]

Hi,

Thank you all very much for wealthy replies. Actually i spend some time experience the attenuations i purchased from Parts Connection (mills) and seems most (if not all) of the problem i had is solved now. I end up using attenuations values of 2 Ohms, but i may need little more. Also i have to say they sound better from the ones that comes with MG-20, the sound now become warm and natural, and i don't hear the HF forward or higher than MID and LOW as before .
I haven't yet order the chokes yet, but I will get them soon .