[berni]

If everything were so easy and explainable or measurable then we all already had perfect systems in our rooms.
Every thing leaves a finger print in the signal, how it performes or sticks out is another part.
Also many of us have different predictions of how it should sound.
I think and many of us that adding resistors is not a good idea. Why then bothering with the impendance of speakers if we could  simply add resistors to fix it? Why a lot of ribbons are driven by autoformers to hoist the impendance and not with resistors.
If you add a resistor your effiency goes down , with this you also degrade the dynamics in a part of the driver which was perfect before the tweak?! How about that? Most of the harshness comes from bad positioning  in the room, backwaves  form the front wall, tv in between the speakers...., and with a bad amplifier not capable to drive the low and middles when a lot of power or stability is needed. Thats when the harshnees sticks out. 
Only my opinion.

[Crimson]

How about if you ask Danny Richie how resistors work and if he uses them in loudspeakers or not? I'm sure he can explain it to you. Maybe you'll respect him enough to listen to what he has to say about it.

Enough already with the insults. You know nothing about me or my background. All I'm saying is adding the series resistors to the mini Maggie alters its tonal balance. It's nothing but a bandaid, and one should seriously look at positioning, the room, and electronics before taking the lazy way out.

[Crimson]

If everything were so easy and explainable or measurable then we all already had perfect systems in our rooms.
Every thing leaves a finger print in the signal, how it performes or sticks out is another part.
Also many of us have different predictions of how it shoul sound.
I think and many of us that adding resistors is not a good idea. Why then bothering with the impendance of speakers if we could  simply add resistors to fix it? Why a lot of ribbons are driven by autoformers to hoist the impendance and not with resistors.
If you add a resistor your effiency goes down , with this you also degrade the dynamics in a part of the driver which was perfect before the tweak?! How about that? Most of the harshness comes from bad positioning  in the room, backwaves  form the front wall, tv in between the speakers...., and with a bad amplifier not capable to drive the low and middles when a lot of power or stability is needed. Thats when the harshnees sticks out. 
Only my opinion.

+1

[rollo]

   Having owned MMG and 3As room positioning cures most of the hot tweeter. Saying that why is the tweeter hot ? The amp ? the source ? No the tweeter. However amp choice will influence the tweeter big time.
   It was always something in the chain that stressed the tweeter. The amp which it was in my case, I did not want to change the amp as the rest of the sound was marvelous. So what to do ?
   Resistor time it was. Tried several values as tone controls basically. worked fine but still no cigar. Eventually when the amp was changed no need for the resistor. Just used a piece of speaker wire.
    Maggies have a revealing ribbon tweeters, period. The gear in front better be correct tonality wise or your gonna hear it.
     The amps used that did not require the resistor for me are; Classe DR 25, Audio Research 250 servo  [ tube change required], Levinson  and now Arion hybrid class D. What did  require the resistor, Krell, Adcom, Bryston 4B, AR Classic 60. See a pattern in character here ?
      If you are not willing to try other amps or sources use a resistor. Deuland would be my choice.
    Disclaimer, we are dealers for Arion.


charles 

[josh358]

If everything were so easy and explainable or measurable then we all already had perfect systems in our rooms.

[ . . . ]

If you add a resistor your effiency goes down , with this you also degrade the dynamics in a part of the driver which was perfect before the tweak?! How about that? Most of the harshness comes from bad positioning  in the room, backwaves  form the front wall, tv in between the speakers...., and with a bad amplifier not capable to drive the low and middles when a lot of power or stability is needed. Thats when the harshnees sticks out. 
Only my opinion.

Hi Bernie,

Agree that everything isn't so easy and explainable or measurable. Fortunately, this is. It's completely trivial from an engineering perspective. There isn't anything about it that hasn't been understood for many years.

The entire idea of adding the resistor *is* to make the tweeter's efficiency go down. That's what makes the tweeter quieter. And room treatment in the same frequency range would have the *same* effect on dynamics and efficiency.

Short true ribbons are coupled with transformers because their impedance is so low that if you used resistors to match impedance, most of the output would go away. Since impedance depends on the length and cross-sectional area of the ribbon, you can't raise the impedance of a short true ribbon high enough without making the ribbon too fragile to survive, so you need a transformer. Maggie ribbons don't need a transformer because they're very long, so they can be made to have a high enough impedance without a transformer. Some models do use a resistor to bring the impedance up from 2 ohms to 3 ohms.

There is no reason, technical or otherwise, that you shouldn't use the tweeter resistors that come with the Maggies. Speakers come with tweeter level controls because rooms don't have them. I'd take Magnepan's advice, though, if you need the 2 ohm resistor your room is too live and you should add some material to it. Also, shelving down the tweeter may produce an undesired midrange cut. Electronic equalization is better, particularly with a two-way like the MMG's.

Turning the speaker on its axis can help, but it can introduce other problems such as crossover lobing. This is going to be room and setup dependent so the only solution is to try it.

[Davey]

The entire idea of adding the resistor *is* to make the tweeter's efficiency go down. That's what makes the tweeter quieter. And room treatment in the same frequency range would have the *same* effect on dynamics and efficiency.

There is no reason, technical or otherwise, that you shouldn't use the tweeter resistors that come with the Maggies. Speakers come with tweeter level controls because rooms don't have them. I'd take Magnepan's advice, though, if you need the 2 ohm resistor your room is too live and you should add some material to it. Also, shelving down the tweeter may produce an undesired midrange cut. Electronic equalization is better, particularly with a two-way like the MMG's.

Well put Josh.  That would seem obvious, wouldn't it.

This thread has taken on a surreal quality.  I mean, for crying out loud, if you're a speaker designer tasked with mating a 92db efficient tweeter with an 86db efficient woofer, how else do accomplish the goal without adding a resistive attenuator in the tweeter path?  You ain't gonna fix that problem with room treatments and speaker positioning.  In the MMG case it's not a 6db difference...more like about 2db....but the basic issue is still there.

(Assuming EQ is not an option.  Many egophiles would declare EQ "removes" information also.) 

Cheers,

Dave.

[Æ]

Enough already with the insults. You know nothing about me or my background. All I'm saying is adding the series resistors to the mini Maggie alters its tonal balance. It's nothing but a bandaid, and one should seriously look at positioning, the room, and electronics before taking the lazy way out.

Yeah, well you know nothing about me or my background either. . . .

There was no insult in my reply, no tone (tone controls switched to bypass). You obviously don't respect what some of us are saying, but then again maybe you'll respect your fellow Facilitator.
 
If the Maggies already have tonal balance, there is no need to upset that balance. But, if they don't have tonal balance then something definitely should to be done about it.
The OP has only provided us with scant information, it's his thread and we are only trying to be helpful. So far no real feedback from him.
Regardless of your education or experience, I'm not the only one in this thread who disagrees with some of your replies. Resistors aren't some sort of Ju-Ju that you have be afraid of.

[rw@cn]

Well you would think that the speaker designer would incorporate that 6 db differential in her speaker design. I've read all of Magnepan's literature and no where do I find any mention of a xyz db differential. They state something to the effect that in some rooms the tweeter may be over emphasized.The implication that Magnepan speaker design is deficient is IMO not correct and Josh didn't make that implication. At least that is my understanding of his post

So you can use the resisters or fix the room. I used the resisters and didn't like what I heard, so I decided to install difussors. I won't go into all of the pros of cons of difussors, they just pleased me more than the resisters.

Well put Josh.  That would seem obvious, wouldn't it.

This thread has taken on a surreal quality.  I mean, for crying out loud, if you're a speaker designer tasked with mating a 92db efficient tweeter with an 86db efficient woofer, how else do accomplish the goal without adding a resistive attenuator in the tweeter path?  You ain't gonna fix that problem with room treatments and speaker positioning.  In the MMG case it's not a 6db difference...more like about 2db....but the basic issue is still there.

(Assuming EQ is not an option.  Many egophiles would declare EQ "removes" information also.) 

Cheers,

Dave.

[SteveFord]

Getting the room right is important and Rollo hit the nail on the head as far as I'm concerned.
These speakers are like big sonic magnifying glasses (to mix a metaphor) and if you're putting something in that isn't up to par it WILL show up.
The higher up you go in the model line up the more pronounced the effect will be.
I'll give you a case in point - I just could NOT get digital to sound right with 3.6s or 3.7s.  They SHOULD sound better than 1.6s or 1.7s but they didn't.  Most of the time they sounded worse to me.
Depending on the CD it would alternate between dull, shrill, grainy, something was just out of whack and was driving me crazy (short trip).  I tried all sorts of stuff and finally came to the realization that it was time to lift the tail of the bull and face the situation.
The solution was to chuck the source and stick in a turntable and problem solved.
How do they sound now?  I think the phrase I used about 2 minutes into the first song was "Holy Shit!" which is a big change from "Something's not right, what the hell is it?".

One last thought - don't let this get too heated, okay?
It's only a hobby.

[Davey]

Who implied the Magnepan speaker design is "deficient?"  I don't like the implication that there's an implication.  This thread is going from surreal to downright weird. 

Magnepan understands the issue well.  If you read the owners manual for many of their speakers you'll find this statement:

"The Magneplanar Quasi Ribbon Tweeter is very efficient in its total "energy dispersion."  If the surrounding walls are exceptionally reflective, the overall perceived acoustical balance will be tipped towards a "hot" high end.  Attenuation is performed through insertion of a simple non-inductive resistor is series with the tweeter."

How much more clear does the POSSIBLE need for an OPTIONAL resistor need to be made?
It seems some in this thread would prefer hanging drapes all over their listening room vice adding a simple resistor.  I see no problem with that option either.....but let's not be blaming an attenuation resistor for mysterious filtering action.

Cheers,

Dave.

[SteveFord]

Has someone implied that there is a mysterious filtering action going on?
That implication is nearly as mysterious as the filtering action itself. 

All kidding aside, from what I could tell they simply recessed the top end a bit which I believe is what they're designed to do if you have a bright room and/or source components.

[*Scotty*]

I offer this as an experimental alternative to the in-line resistor, try inserting a piece of 8ga. THHN solid core wire about 6 or 8 inches long in place of the resistor. Start with the 8ga. piece first and if the effect is too pronounced switch to the 10ga. The procedure is to start with 8 inches of 8ga. and trim to length, the shorter it is the less of the effect you have.
 This is kind of the opposite of a non-inductive resistor but there shouldn't be a perceived loss of dynamic attack.
Lowes or Home Despot has this wire by the foot.
Scotty

[rw@cn]

Who implied the Magnepan speaker design is "deficient?"  I don't like the implication that there's an implication.  This thread is going from surreal to downright weird. 

Magnepan understands the issue well.  If you read the owners manual for many of their speakers you'll find this statement:

"The Magneplanar Quasi Ribbon Tweeter is very efficient in its total "energy dispersion."  If the surrounding walls are exceptionally reflective, the overall perceived acoustical balance will be tipped towards a "hot" high end.  Attenuation is performed through insertion of a simple non-inductive resistor is series with the tweeter."

How much more clear does the POSSIBLE need for an OPTIONAL resistor need to be made?
It seems some in this thread would prefer hanging drapes all over their listening room vice adding a simple resistor.  I see no problem with that option either.....but let's not be blaming an attenuation resistor for mysterious filtering action.

Cheers,

Dave.

It is obvious that we disagree on the semantics of the manuals and wordings of our posts. I am bowing out of this discussion (with you) for now.

[rw@cn]

I offer this as an experimental alternative to the in-line resistor, try inserting a piece of 8ga. THHN solid core wire about 6 or 8 inches long in place of the resistor. Start with the 8ga. piece first and if the effect is too pronounced switch to the 10ga. The procedure is to start with 8 inches of 8ga. and trim to length, the shorter it is the less of the effect you have.
 This is kind of the opposite of a non-inductive resistor but there shouldn't be a perceived loss of dynamic attack.
Lowes or Home Despot has this wire by the foot.
Scotty

I was advised to use the same wire as the main speaker connection wire. This has worked well for me.

[Davey]

Has someone implied that there is a mysterious filtering action going on?
That implication is nearly as mysterious as the filtering action itself. 

All kidding aside, from what I could tell they simply recessed the top end a bit which I believe is what they're designed to do if you have a bright room and/or source components.

Steve,

It's been mentioned more than a few times that resistors "remove a lot of information."  Is that not an implication of some sort of "filtering action?"  I used the term "mysterious"......sorry about that.  However, since no one has yet answered my query (from a page or two back) of HOW said resistor "removes the information" I still believe it's a "mystery." 

Speculation and subjective analysis are fine.....but we always have to keep in mind that's ALL they are.

Cheers,

Dave.

[rw@cn]

Steve,

It's been mentioned more than a few times that resistors "remove a lot of information."  Is that not an implication of some sort of "filtering action?"  I used the term "mysterious"......sorry about that.  However, since no one has yet answered my query (from a page or two back) of HOW said resistor "removes the information" I still believe it's a "mystery." 

Speculation and subjective analysis are fine.....but we always have to keep in mind that's ALL they are.

Cheers,

Dave.

I may not agree with your choice or words but here I agree with you. Resisters do what they do, they lower the level of a signal. I will say that some resisters are better than others.

[Davey]

I offer this as an experimental alternative to the in-line resistor, try inserting a piece of 8ga. THHN solid core wire about 6 or 8 inches long in place of the resistor. Start with the 8ga. piece first and if the effect is too pronounced switch to the 10ga. The procedure is to start with 8 inches of 8ga. and trim to length, the shorter it is the less of the effect you have.
 This is kind of the opposite of a non-inductive resistor but there shouldn't be a perceived loss of dynamic attack.
Lowes or Home Despot has this wire by the foot.
Scotty

8 awg THHN solid core wire is approximately 0.00068 ohms per foot.  The Magnepan MMG tweeter is 3.6 ohms.
One foot of 8 awg THHN wire would provide an attenuation of....20*log(3.6/3.60068)....or approximately -0.0016db.

The THHN wire may do something for you.....but it's not by providing attenuation.

Cheers,

Dave.

[*Scotty*]

Davey,you are correct if any change is heard it is not due to attenuation from an increase in resistance. If you are using any Magneplaner loudspeakers you might try putting about a foot of 6ga. THHN solid core in place of the the jumper or resistor you have in place. The 6ga. is approximately 4.11mm in diameter and I think it will fit in the hole.
 If you hear any change in the highs it might be due to a gross failure to fully saturate the conductor at the higher audio frequencies resulting in the signal failing to completely exist as an external EM field on the conductor. Bear in mind that I am hypothesizing about potential causes of any differences that might be heard here.
Please try it and see if you hear any difference in how prominent the highs are. I would do just one channel here and see if there is any perceivable change in the stereo image as a result of a channel imbalance.
Scotty

[Davey]

Scotty,

Your theory is that skin effect is causing attenuation at higher frequencies?

With 8 awg wire skin depth would be less than 100% with frequencies higher than a few kilohertz.  However, this IS eight gauge wire we're talking about, so there's a LOT of conductor...even in just the outer portion.  And it's copper and not aluminum or some other material.  And it's only eight inches. 

I can't disprove your subjective evaluations (one of the very 'convenient' things about subjective evaluations) but it would be nice if these suggested "solutions" for this issue had the least bit of theory or objective evaluation to back them up.
To test your theory.......If I incorporate some THHN into the tweeter leg of my MMG's I should be able to take a differential measurement across that piece of wire (at high frequencies) and measure a difference, shouldn't I?

In fact, I surmise, if a user notices an audible difference when substituting THHN wire into the tweeter attenuation terminals the difference is more likely because of the removal of the phoney non-copper jumpers and re-establishing tightness on the set screws, vice some electrical qualities of the copper wire.  Maybe I'm all messed up? 

Cheers,

Dave.

[*Scotty*]

Davey, lazy person that I am, I would start with the most extreme condition first. Just stick a one foot chunk of 6ga. THHN in the resistor position on one channel and listen for any differences. If you hear any difference then you could try to measure what is happening.
 Start with the experiment first, then figure out a test jig to measure what is occurring that might provide causation for the observed phenomena.
Scotty,