Anyone use the tweeter attenuation on Maggies?


Ok, I am in the process of demoing a pair of Magnepan 12QRs from local dealer and they are doing exactly what I hoped in the three-dimensional soundstage area but come across as too bright for my taste. My room is well damped so that shouldn't be the problem. The dealer said the speakers were broken is so not the problem either.
My question is, has anyone tried using a 1 ohm resistor in the tweeter path to soften it a bit. The manual mentions this method so it must have been brought to their attention many times. Any other suggestions?
My room is 11X13, maybe a bit small for the speakers but as I said, it is well treated so the only problem is visual.
Basic system is Resolution Audio CD-50 (very smooth), Bel Canto Pre3 and PS Audio A-100. Speakers that work best for me have been the Meadowlark Audio Kestrels. Thanks.
timrhu
Tweeters are generally more efficient than woofers, so crossover networks typically include a "tweeter padding resistor" in series with the tweeter. Because Magnepan makes both the woofer and tweeter sections of their speakers the tweeter is sometimes OK without any padding resistor, but if you find the speakers "bright" don't hesitate to use a padding resistor. Magnepan suggests one ohm. I use 1.5 ohms. 3 ohms is not uncomon in other speakers. Those manufacturers don't have control of tweeter efficiency because they don't manufacture them.
How far out from the wall do you have them? They need at least 3ft preferably 4ft to balance the bass with the terble.
They are 34 inches from the back wall. If they were too close to the wall I would expect excessive bass. Actually the bass seems very good, better than I expected. Working with the toe-in made a huge difference earlier today but the harshness is still there with certain recordings.
The issue is excessive treble. If the music is well recorded they sound very good, I'd say keepers for sure. But if the recording is poor they sound extremely harsh.
My system is built to sound good (listenable) even on poorly mastered recordings. If these speakers aren't capable of this then there's no reason for me to pursue them. They are sounding excellent now with XTC's "Apple Venus."
Thanks, keep it coming.
>They are 34 inches from the back wall. If they were too close to the wall I would expect excessive bass.

Dipoles don't work like that.

Conventional speakers have more bass when located near walls because the reflections coming off the back side add in-phase with the direct sound.

With dipoles the sounds coming off the back side start out at 180 degrees out of phase with the direct sound so close placement to the front wall results in too little low bass which is the same thing as too much treble.
I don't use tweeter attenuation, but I do find it necessary to deaden the corners behind the speakers. The room is about 8'x 17'x 22' and is carpeted with absorbant sofa and loveseat. The speakers are about 4.5' out from the back wall. Corner treatments can make all the difference.
I use a 2 ohm resistor on my MMGs. Without them, the sound is too bright and grainy and I understand the situation is more extreme with the 12s. Also, you need to read up on the choke tweak in the Audio Asylum Planar chat room.
I tried the attenuators on my MG111A's on a few occasions and the sound always was worse. Sure, it attenuated the treble, but, along with it went alot of air and life. It is like the same reason I never liked Dolby with my tape recordings. Sure, it removed the hiss, but, along with it went alot of air and life. I think you are better off treating the system with room acoustic treatment if necessary. It's alot of work though to get what you want without sucking the life out of the sound. I found the Michael Green Room Tune products to be invaluable.
I use 1 ohm resistors in my 3.6's. With ETF 5.8 software run on my laptop measuring system, I measured a slightly upward tilt in the treble referencing flat at 1khz and rising up 2db at 20khz without the resistor. I would prefer an inroom response of minus 2db at 20khz which is what I get with the 1 ohm resistor. In my room a slightly downward tilt sounds best. The sound was certainly more open and detailed without the resistor but I couldn't live with the upwardly tilted frequency balance. Tweeters to the outside helps attenuate treble response a bit as well.
I forgot to mention Magnepan's statement that the MG1.6 (and probably other models) measure flat without the resistor. However, it is claimed that recordings often ramp up the high end to compensate for typical speaker roll off, so it may be necessary to roll off the Maggie response to match what the recording expects.
Thanks for all the responses.
Drew, I wasn't aware of the lower bass when near wall. I have moved them out a few inches and am now exceeding 3 ft.
Hifiharv and Brownsfan, my room is well treated. I use mostly Aurelex products but have some absorption panels also. Corners are treated with bass traps.
Jult52 and Jimburger, I am picking up some resistors from the dealer tomorrow. We'll see how they work.
I do appreciate the comments. It is reassuring to know people do use the resistors. The sonic presentation is what I had hoped for with these speakers but I can not live with the hot (to my ears) treble. One of my main goals is to be able to listen to poorly engineered music I like without being driven out of the room by excessive upper frequency energy.
Put in the 1.2 ohm resistors and listen
should be what the DR ordered in most rooms
dont worry what the other kids say if you like it.
Cheers Johnnyr
SETUP
Have you tried tipping them back with the little nylon washers/ spacers?
Have you tried a little additional toe-out?

Both adjustments will leave frequency response untouched while getting you out of the direct 'beam' of the HF driver part of the panel.

#1 key to Maggie happiness is setup, IMO Resistors are Absolute Last Resort
I use Auralex in the corners. If you already have some of these, it might be worth moving them to the corners instead of the bass traps. I have the corners treated floor to ceiling. I could not live with my 1.6s without the corners treated. Even with the current treatment, there are some recordings that are relegated to the car.
Talked to the dealer and am going to pick up some resistors today. Also. I moved the speakers out into the room as suggested, wow, what a difference. Much improved. We'll see what the resistors do.
Brownsfan, I used the term bass trap lower case. What I do use are Aurelex panels that are affixed to acoustic ceiling tiles and running about 6 feet high.
Magfan, the 12s come with feet that give them a tilt back. I tried propping them up to nearly vertical. They sounded good in the listening chair but terrible anywhere else in the room.
The comments are appreciated.
Toe in will increase treble response at the listening position. Parallel to front wall will calm the treble a little. Also, try swapping speakers left to right so you can compare sound with tweeters "outside" vs "inside".

It certainly won't hurt to try the resistors. Another approach is to replace the stock crossover parts with high quality botique parts. You can visit the Audio Asylum Planer Speaker board and find a ton of info about mods there.
Wgallupe writes
>Toe in will increase treble response at the listening position. Parallel to front wall will calm the treble a little. Also, try swapping speakers left to right so you can compare sound with tweeters "outside" vs "inside".

Toeing the speakers in past the listener will reduce both on-axis treble and higher frequency energy going into the side-wall reflections. "dipoles" with low enough frequencies they act as acoustic dipoles see reduced side and front-wall first reflections in that part of the spectrum too.

FWIW, an acoustic dipole has response -3dB compared to the direct sound at 45 degrees off-axis, -6dB at 60 degrees, and -12dB at 75 degrees. Additional toe-in moves the side-wall first reflection farther into the null on the outside of the speaker and front-wall first reflection farther into the inside null.
After installing the resistors (1.2 ohms) from the dealer and playing a bit more with the position the speakers are sounding very good. I plan on listening a bit more and then swapping my Kestrels back in. I have a feeling though that the Maggies will win this contest. They really do seem to disappear.
Thought I'd finish this thread off.
After careful evaluation the Magnepan 12s went back to the dealer. I tried all of the suggestions that were possible in the week that I auditioned them but they never got me there. I spent about two solid hours Wednesday evening listening to various music, some well recorded and some not so well recorded. On Thursday I swapped my Kestrels back in and listened to the same music. The Kestrels were truly better for me.
I won't spend time critiquing the Maggies but they just did not work in my small room. Thanks for all the suggestions.