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In Reply to: RE: Why two subs at 50 Hz posted by Satie on March 28, 2014 at 21:07:28
Satie, JL mentions it in terms of the MMGs, which Magnepan never positioned for "serious listening". Some of us are hard headed (or poor, like me) and challenged this by modding/tweaking. Dealing with it did cause me some aggravation long ago. (In the end, the tweaking was fun and I am having a hard time accepting that I should "stop tweaking".)
OTOH, until the day I have other Maggies to measure channel vs channel, I will not be sure of how much this tuning mismatch is also used by Magnepan in other Maggies. I do get the impression that the more recent models have less of it.
Follow Ups:
At the same time I wonder how in the world people rave about an speaker that is built like of a 10 year old with different woofers on the left and right!? hehehehe
This would have never left a manufacturing company that produce box speakers.
It would just look extremely un-serious to blend 2 differently equipped speakers and sell it as a matched pair. hahahaha
But then again, a customer can not see this mix of speakers on a closed MMG and just in the same time goes to show that You actually CAN sell what ever You like to some people and they will still rave about it.
And then again, some can't afford the right sound and just bare with the faults.
To be back on topic, Yes You ought to have 2 subs as You CAN hear lower frequency placement.
Cheers!
The one who succeeded was the one who didn't know it was impossible.
Of course, channel balance is just one parameter of SQ. While it does merit much attention it is not the sole determining factor by itself. In any event, to be fair to the MMGs one has to recognize that they have tremendous potential. They SURE are handicapped from factory! Yet, they don't need to stay this way...which is really the ONLY point that I really want to make with what follows.
To begin with, please remember that Maggies -- all of them -- are easily affected by the room factor. Furthermore, I can show you great quality box speakers that STILL will be affected by their rooms into displaying more channel imbalance than what you see in the sweeps below (my friend's boxes in his family room and my MMGs at my home).
The sweeps above are of a friend's box speakers. they cost 20x + what my MMGs cost. I truly love how they sound. Impressive performance that, in fact, to most people WILL sound much better than my MMGs . I chose these B&W for him years ago...yet I would not do so for myself. I still prefer my MMGs despite some limitations.
What you see here is from exactly the same signal to each channel into my MMGs. I use no EQ (although the room & the design of the PLLXO count, in a manner of speaking). Of course, the system IS substantially modded. The mods are exactly the same for each MMG. The PLLXO biamp is using slopes & points close to the original 1st order(for tweeter) and 2nd order (for mid/bass). [However, there are filter caps to reduce the very lowest bass signal...I explain later on].
OTOH, as we know, each speaker was tuned differentially at the factory (14 years ago when Magnepan built them, BTW). In addition, I may have mentioned that the wall on the right side is denser (drywall over concrete) than on the left (hollow drywall). This boosts lower bass a little more on the right side.
How good can they get to be? Let me tell you what I think nowadays: If they could last long enough, I'd rather keep my modded MMGs until I can afford 20.7 or something in the 20.x series. I fixed the "fixable" weaknesses in these MMGs. Anything less than 20.x series would still require significant "fixings" in other models because of all the limitations they all share (pun intended : - )) .
BTW, that 32hz bass note CAN BE HEARD from my MMGs-- faintly but surely, LOL! The interesting thing is that this happens despite an electrical signal that is already attenuated by about 6db at that point .
Why attenuate it? Well, because that driver shares the mylar with another driver (tweeter, in this case), like many other Maggies do. The lower the signal strength, the lower the IM distortion on the other driver...be it a tweeter or a midrange.
In any event, as we already know, the 6db+ being cut from the music or electrical signal would never have come out anyway. No need to risk having it distort things...and in fact, this further helps the QR tweeter approach true-ribbon clarity much more often.
This particular setup still yields a superbly dynamic planar that DOES NOT need a subwoofer to impress with decent impact. I mean, it hits you and still stays clear and well textured.
Of course the B&W 802D are most impressive because they can go lower by themselves. Yet, my MMGs are more natural-sounding within the range they cover. Anyway, the good thing is that most folks can mod their MMGs to do the same if they wish to walk the walk. I don't think we want to discourage them from doing so, do we?
After all, unless they get 20.x, all larger Maggies "share the Mylar" and ARE single pole...
Yes, You are right JBen, the room does have an extreme effect on the performance of a speaker.
Then again one should be aware of that one have a LOT of opportunities to treat the room with various products bought or DIY made.
This is however NOT the case with a speaker that is made with an imbalance from factory.
This is what I am talking about.
To make a speaker as balanced as a company can will give the best starting point for a customer.
However if the company by default and on purpose makes the speaker unbalanced, then the customer is "locked".
The reason for doing this is clearly because the company wanted the speaker play with the big guys with the ability to go lower in frequency.
If they had made the speakers symmetrical, then they would not reach the low frequencies that they can today.
So, it's a compromise.
But at the end of the day, if the customer can not hear this then there is no problem, right!?
Cheers!
The one who succeeded was the one who didn't know it was impossible.
This left/right imbalance thing REALLY bothers you, doesn't it? :)It would be extremely easy for Magnepan to make the tuning dot locations identical for both left and right speakers. Why do you think they don't do that?
Try the experiment I posted in the other thread and see if you can audibly hear the difference between left and right MMG's or 1.6's. It's actually a worthwhile test.
Dave.
Edits: 04/06/14 04/06/14 04/06/14
The reason for them to differentiate the left and right from each other is because the speakers can not reproduce the frequencies that Magnepan wanted to target if they were symmetrical.
The one who succeeded was the one who didn't know it was impossible.
You realize that's not the reason, don't you?
I think you have a basic misunderstanding of the MMG/1.6/etc design. :)
Dave.
No, actually I am perfectly sure that I am right.
Do You know the reason for tuning buttons and the different distances?
I am sure some other inmates gladly would explain that part of construction fact for You. ;)
Cheers!
The one who succeeded was the one who didn't know it was impossible.
Yes, I think that your are very correct in that many folks won't hear the resulting effect of such an approach.One wonders what would have happened if Magnepan had not chosen to do this. In other words, to not make them at all, or to make them "properly" & balanced but at a much higher price. For that matter, if Magnepan had not found similar engineering shortcuts for the other Maggies the planar speaker category would be much much smaller, LOL!
Handicapped as they are, MMGs do offer a low-cost entry point to the world of planars. Furthermore, within a range, the darn things do reproduce music better than other more expensive speakers. That they still serve not just as an introduction to higher-end Maggies but also provide a DIY gateway to very decent music playback is great.
For example, one surprising thing came up around the time I first measured my friend's 802D in 2009. I had just recently added "pseudo-frames" to my MMGs. (This was the prototype for what became my "Stixbees" frame reinforcemnt later on). With the P-F , when I compared distortion figures at the time, the MMGs were better or slightly better than the 802D (in the frequency range they share). I was so surprised, that I DID NOT believe it at first. As I remember it, even at 40hz the 802D were showing 8% distortion during a sweep (each speaker). Fainter as my MMGs were at 40hz they were at 8% (right) and <8% (left). This was dynamically, while doing sweeps. (I have not been able to do pure, single-tone, harmonic distortion tests on those 802D yet).
To be sure, the rooms themselves -- and the corresponding ambient noise -- may have imposed a toll on the accuracy of distortion figures. Nonetheless, by the time the sweeps had reached 1khz, the MMGs were delivering <0.5% where the 802D delivered > 1% THD. Given that I could repeat the results, in those days I was mighty proud of the MMGs.
BTW, comparable distortion figures were depressingly high in my un-reinforced MMGs. The fact is that their original MDF frame is very THIN, about 1/2"; much thinner than current MMG models. Lower distortion, more clarity at higher SPL, and part of the deep bass improvements came from just the frame reinforcement.
Yet, frame reinforcement was just one of several tweaks, the totality of which can be done for low or very low investments.
I, for one, was not going to be able to get decent speakers at the time when my wife's illness was costing us so much money. These used MMGs allowed me to get a music system started again. Then they offered more...if I put the DIY work into it.
Thus, I'd like to nurture general awareness of this potential. It is available to others who may fall in my situation, or just for the fun of it. Those who may want to extract more juice from MMGs (and other Maggies) may find surprising how little money it really takes.
LOL, I am currently dreaming of the 20.7 or something similar! However, guess what? I now have to pay my own new huge medical expenses. Then I have to find even more money for a larger place to live in because setting large planars up in the patio simply won't do : - )) .
I reckon that this will take time...quite a bit of time.
Edits: 03/30/14
The MMG are my recommendation for the offhand affordable planar query. Despite the lack of balance in the lower freq limiting the potential of the speaker.
As you go on tweaking and increase the rigidity of the speaker and adjust your room treatments, the basic asymmetry becomes a more significant issue limiting performance.
For the vast majority of people considering MMGs their inherent design limits on performance will never be this asymmetrical tuning. They will never place them ideally nor treat the room, nor power them sufficiently.
Finally, they will stream 128bit MP3, and improve the performance with a single subwoofer placed on one side.
I understand the marketing aspect for the design decision as the target market is not perfectionist audio, just not in the context of the company's basic philosophy.
"For the vast majority of people considering MMGs their inherent design limits on performance will never be this asymmetrical tuning. They will never place them ideally nor treat the room, nor power them sufficiently."
Absolutely right, Satie. Let's tell the rest.
In addition, for those willing to do the right things, the MMGs can be tweaked to superb comparative performance. It will not be limited by the asymmetric tuning but it will (usually) be limited by the lack of a true-ribbon tweeter and the need for a larger bass driver for deeper down reach. (But do call Satie for good pointers on Neo drivers & ribbon tweeters!)
In addition, like most other Maggies the TWO REAL limitations -- a single magnetic side AND sharing the Mylar for two drivers-- will remain in your MMGs.
Luckily, even though this is not ideal for faithful reproduction these are no showstopper. In fact, some properly tweaked MMGs will outshine some of their larger monopole brothers in dynamic impact and textures replication (unless you go tweak the larger brothers, of course).
Still, if you want it ALL from Maggies, the 20.x series will be waiting for you when you are ready. In the meantime, Magnepan offers a solid & delightful lineup of speakers that -- despite their design compromises -- will wow true music connoisseurs all over the world, like few speakers can do.
So, treat/tweak any Maggies properly. With a little work, even the cheapest of them will not only delight with MP3s...it will show the true meaning of high resolution audio, from analog LP to DSD/SACD and Blu-ray.
I think You are right Satie!
The one who succeeded was the one who didn't know it was impossible.
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