Review Of Magnepan MG-1.7QR|
The purpose of this page is to give a fair and critical appraisal of the new 1.7 model. I am doing this because as usual there is more hullaballoo and hearsay than actual facts out there about it, and those facts it turns out are a bit disappointing.
In short, and read this carefully it is my opinion that if you do not already own any model of magnepan speaker and it is your intention to mod them to take them to their full potential then do not buy a 1.7, buy a used 1.6 instead. If you already purchased the 1.7 you have a decision to make. My feeling is it's worth the loss to sell them for what you can and buy used 1.6's and mod them instead. That said the 1.7 can be made much better but you won't get anywhere near the bass you get from the 1.6 nor will you realize the dbl level increase the others get from the XO. Expect to need a sub to realize full bass potential. To understand why continue reading. If you plan to keep them stock however (which makes one wonder why you are even here reading this) then you would probably prefer the 1.7 as it appears to not have some of the more obvious issues the 1.6 has. Appears and obvious are the key words however as IMHO they both have serious issues stock.
How it differs? The 1.7 is essentially a 1.6 but for 2 differences. First, its' entire driver uses QR foil for the voice coils, whereas the 1.6 only uses that material for its' tweeter. Second, it uses a rather odd shared series type XO and instead of being 2 "drivers" (midbass and tweeter) like we find on the 1.6 there are now three - Midbass, midtweeter and "super tweeter". Here is a pic of the driver and yes, you can see even with QR foil they damaged it applying the tension button. I really hope this issue ends.
What is a Super Tweeter? Simply put, a marketing gimmick. The 1.6 uses 13 "loops" of midbass wire and 4 "loops" of QR tweeter wire. The 1.7 also uses 13 loops for the midbass only it's QR foil, and it also has 4 tweeter loops only 3 of them are broken off to be a "midtweeter" and the last, single loop is the "super tweeter". Given that the QR wire on the 1.6 is the same as the stuff on the 1.7 is, one must wonder how reducing the tweeter from 4 loops to 1 makes it super? It doesn't. That change in fact lies in the XO.
The crossover on this model comes right out of a horror flick. My XO guy said his computer really didn't like it. I know from a customer (who's comments appear below) and from my own stock listening that it has 2 very bad humps in it, (which seems to be the norm when you break maggies up into more and more drivers) but what makes it very odd (and gives it its' "super" status) is it's design allows the highs to drift down not only into the midband but the upper bass regions as well. Here is a photo and the stock schematic. Don't ask me to explain it if it doesn't make sense, and as you can see in real life it's wiring is a mess.
What does it all mean? Stock I find the 1.6 very bright and fatiguing after 15-20 minutes. I did not find the 1.7 bright in this regard and in fact I thought it had an "exciting" quality at first and that it was rather dynamic. That lasted for 15 minutes until my brain caught up to the trick. This intrusion of highs into the lower bands is what gives the speaker its' sense of dynamics and the "exciting" quality, however if you have a discerning ear you'll not only grow tired of it, you may begin to resent it as I did. It makes music simply sound wrong. Not fatiguing, but my desire to listen to it is just as absent. IMHO it is a wiring trick designed to remove the 1.6's overt brightness on top but to keep the speaker artificially bright anyway by smearing that brightness all the way down to the upper bass regions. Spread like that it is not in your face and it gives the speaker a false sense of dynamics. Sadly those false dynamics hide the fact that it's bass performance is very poor.
It was my feeling however that once modded these problems would vanish. The obvious solution was to rejoin the tweeters back together into a regular "less than super" tweeter and treat it then like a 1.6 which is what I did. In this regard it was a complete success and it mods exactly like the 1.6 in abilities and performance but for 2 troubling issues.
First it was very clear it's bass reproduction is not as good as the 1.6.
Second it is the first of every model I have done (and I've done almost all) that did not get a decibel boost from using this XO.
In every other aspect it is identical to the 1.6 and it may even be slightly better in mid "delicacy" but I did not have it here long enough to really tell, and I'd want to A/B it against a 1.6 before making that call.
Now, why would it be worse at reproducing bass and why would it fail to realize the decibel increase (from about 86 stock to around 92 post mod) that every other model did? I feel both faults lie on the head of the QR foil. Bass reproduction takes mass (they don't make subs using QR foil) and decibels is also a measurement of "force" and since the QR foil is so light and "mass-less" it cannot sustain a bass wave properly or generate increased volume. To do that would have required much more powerful magnets which Magnepan did not use. That being the case there is no way around this and it must be considered an inherent flaw.
One thing of interest is used stock this massless quality of the QR foil means it can start and stop faster than the older thicker wire, so if it can stop faster it won't be as effected by wave contamination and smear from the MDF frames that other maggies are. It is still a problem, however the 1.7 probably plays a little "clearer" stock because of this which again adds to the impression and listener comments that it is more dynamic. It would be more correct to say it's just a little less dirty than the ones that went before, not that it is more dynamic.
I believe my mod takes it up as far as it can go and if you own one don't fret, it can be made nice. However I do not recommend the 1.7 to those looking to buy if they have not already, and in fact I would not be surprised to see a 1.8 at some point when this models flaws get realized by everyone. My guess is a 1.8 would re-introduce the normal midbass wires but it would retain the unusual XO of the 1.7. This would hardly be unsual for this company as almost every model has gone thru several incarnations. (1.4, 1.5, 1.6 or MGII, IIa, IIb, IIc etc...) However, maybe this XO gimmick only works when the entire thing is QR foil, so who knows. If it stays like this and all other models follow, it's going to be a black future ahead for us.
What follows is the comments of the first guy to get a pair of 1.7's modded by me.
"Just wanted to thank you again for doing such a beautiful job on the speakers. I couldn't be happier with the look! I don't know how you did it, but they really did turn out to be as I had pictured them in my mind (and even better :) They look fantastic! I can't wait to invite my friends over and show them off! :)
"I'm crazy busy at work so I still haven't gotten pictures done, but as for sound ......in a word wow. With your modifications I feel this speaker has achieved its full potential. I've experimented with various speaker placements but keep coming back to where I originally had them prior to the mod. This position was calculated using a couple different mathmatical methods and adjusted from there through extended listening and measurement of the frequency response.
For frequency response and sound level measurement purposes I set them up positioned exactly as I had them before. I had placed tape on the floor in such a way that I would be able to duplicate the pre-mod positioning. I have a CD with test tones running from 20 Hertz to 20,000 Hertz. What makes this test CD a bit unusual is that it was made specifically for the model sound level meter that I have so that it compensates for the response curve of the meter making for a more accurate measurement. Accurate or not, I am confident in the repeatability of measurements which to me is critically important.
I found when measuring the pre-modded 1.7s in various configurations that I was able to get consistent, repeatable measurements when I returned the speakers to a position I had measured before. Therefore, that gives me confidence that my pre and post mod comparisons are valid and meaningful.
In a nutshell, what I found pre and post mod was that (similar to what we discussed) the bass and lower midrange actually measured the same even though the bass "sounds" louder now (fuller, richer, deeper etc.) even though the decibel output remains the same (according to the meter anyway). Interesting.... What is different however is the mid and upper midrange through to the highest treble is flatter than before. Most notably, the pre-modded version had a large spike at 1,000 Hz in the heart of the midrange and another at 8,000 Hz in the treble (regardless of room positioning or treatments). Some things I did helped lessen the spikes, but they were always there. Now those spikes are gone. My guess is that your crossover has much to do with the flatter response and perhaps the pre-mod "supertweeter" had something to do with the treble spike.
Putting the meter away my initial listening impressions are that the mids and highs are now more detailed and the initial attack of instruments sounds "rounder", more natural and to use that overworked phrase "more musical". The mids and highs also sound sweeter and smoother and complex musical passages sound clearer and more detailed. I can more easily pick out individual voices of singers and I'm also picking out small details in familar recordings that I didn't hear before.
I have a home made subwoofer, (15" passive radiator with a 10" driver), that integrates quite nicely with the 1.7s. I will be experimenting with other room positions as you had suggested and comparing measurements and listening impressions. In all my pre-mod measuring I forgot to note where my volume was to obtain a certain sound pressure level but from what I remember it seems to me the efficiency is about the same - maybe a wee bit better than it was stock but certainly not the large difference you noted in the other models."
And then in a follow up note...
As indicated in my initial impressions the frequency response of the highs measures flatter and the sound is smoother. The strident nature of the stock sound is gone as in the "snap blur" effect you've described that occurs in the stock speakers. The overall frequency response measures the same in relation to the lows and highs. Bass output measures the same as stock although it has a fuller sound (I'm sure from the much improved crossover) although one definitely needs a sub with the 1.7s to get
serious bass with or without the mod. As mentioned before efficiency is about the same, no big improvement as seen in the other models.
Imaging, soundstage, "dimensionality" however you want to call it is simply outstanding. I found that in my room (28 feet long and 23 feet wide) the imaging with the stock speakers was impressive in comparison to the MMGs I had, and the 1.7s were
also more detailed in comparison. Well now all that is turned up several notches. When I play a CD or LP that is well mastered.....WOW....It is like the performers are right here in the room. If I close my eyes so I can't see the speakers (which is hard to do as they are absolutely beautiful :) it doesn't seem like the music is coming from speakers at all. It is as if there is a live performance in my room. This large a sound can't be coming from speakers! Very musical and a joy to listen to."
In conclusion if you bought one, have no worries, it can be made right. However if you have not the fact is all things being even the 1.6 "cleans up" better so it is obviously the preferred choice if this is the size and type maggie you are looking for. I hope this has been of help.