AudioCircle
Industry Circles => GR Research => Topic started by: FLEMKE on 23 Aug 2016, 12:46 am
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Is there a difference between the two? I own a pair of 1.7i's and think replacing the crossovers would give my something to do this winter.
Tim
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Is there a difference between the two? I own a pair of 1.7i's and think replacing the crossovers would give my something to do this winter.
Tim
Hey Tim,
I wish you were close by. I'd love to help you with that.
Here is an upgrade I did for the Maggie MMG's: http://www.audiocircle.com/index.php?topic=141550.msg1517919
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Danny,
I saw you post about the MMGs. That was why I posted here. I may just have to open them up!
Tim
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Is there a difference between the two? I own a pair of 1.7i's and think replacing the crossovers would give my something to do this winter.
Tim
Just curious, what is it that you do not like about the 1.7i's? I own the 1.6's and MMG's and have heard the 1.7's. 3.6's, 3.7 and 3.7i's. Maggies are finicky about amps and preamps as well as positioning. They like lots of high current power.
I use to run my 1.6's with a Parasound A21 and an AVA hybrid tube preamp. They sounded good but not great, but when I went to a Pass Labs X250 amp and a BAT preamp they really came alive and sounded so different.
Also, adding a high quality subwoofer makes a huge difference.
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I have a BAT VK-75 which is modified. The crossover upgrade makes for a rather impressive upgrade. I have seen a pic of the 1.7 crossovers and they are fairly simple. I guess it's just part of the sickness to try and make it sound better!
Tim
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I would advise that you build or buy an enclosure for an external crossover, this gives you maximum flexibility for parts size and placement. If you look closely at the image below of the Maggie 1.7, you will see a 75uF 100volt cap hiding in there, that appears to be a non-polarized electrolytic capacitor. The total value of caps in the cross over if replaced in their entirety with high quality caps will represent a substantial investment. There is no reason to expect that a very different crossover resides in the 1.7i. You should also plan on duplicating the DC resistance of any inductors you replace.
(http://www.indiespinzone.com/mag/17a.jpg)
Scotty
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Did you get that pic from the Gunn website? I would certainly be taking my time to match things up correctly.
Tim
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That's where I pulled the image from.
If you do go outboard with the crossover I would be damn sure I duplicated crossover circuit exactly. The crossover schematic on the Gunn website doesn't make a lot sense to me and there are supposedly some kind of differences between the 1.7 and the 1.7i which remain undisclosed by Magnepan.
In lieu of deriving a circuit diagram from observation of the crossover network, it might literally be easier to just put extensions on the existing connections from the panel to the crossover and move the entire assembly outboard and replace the components one at a time within the existing wiring harness. Once this was done the wiring between the components could be also upgraded one piece at a time. It would also be a good idea to take a photo of the stock cross over in situ before anything is done as a reference.
Scotty
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Everything on the Magnestand website of a technical nature is highly suspect. Peter Gunn (John) himself doesn't even know what a crossover is, so I would take everything there with a grain of salt.
The newer X.7 speakers are all series crossovers. You guys are aware of this, yes? I keep somewhat informed on the modification activities of Magnepan users but I have seen no schematic drawings of these newer speakers that I would 100% believe are correct. Magnepan is no longer supplying schematic diagrams for their current models, unfortunately.
Regardless, if you want to really improve those speakers you need to remove the whole stock crossover and reconfigure the setup for bi(tri)-amp operation. Anything else is just turd polishing. If this is beyond the capabilities of any contributors, I think I would be inclined to just leave well enough alone.
Dave.
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I picked up the 1.7i's for a song and have $1500 I can blow on the mods. Chicago winters suck and I need something to keep from going insane!
Tim
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Everything on the Magnestand website of a technical nature is highly suspect. Peter Gunn (John) himself doesn't even know what a crossover is, so I would take everything there with a grain of salt.
Dave.
I would have to agree with this statement from Davey. Really just about everything about the network that is on there is just so very wrong. I really question any of the after market networks for those things that don't include actual measurements from the speakers.
For me to go through them and design a new network for them is a piece of cake, but I would have to have the speakers here.
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Danny,
That's a 14 hour drive. You never know. The pic is of the OEM crossover if I am not mistaken.
Tim
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I would have to agree with this statement from Davey. Really just about everything about the network that is on there is just so very wrong. I really question any of the after market networks for those things that don't include actual measurements from the speakers.
I'm not talking about acoustic measurements of the speakers. I'm talking about examining and redrawing the schematic (correctly) into a standard format. That way you have a proper baseline reference for the electrical transfer function of the network. Acoustic measurements can come (much) later.
No doubt you would find these speakers would not measure acoustically flat and would not conform to some idealistic response curve you had in mind. However, that's essentially irrelevant because we don't know what acoustical target the Magnepan guys had in mind.
The 1.7's have been pretty much universally praised, so either the Magnepan guys pretty much know what they're doing or they got pretty lucky. I think it's probably the former. :)
Dave.
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Davey,
From what I have seen of their designs I am not sure they have an acoustical target. The SMG model that I measured a few weeks ago was beyond help. The tweeter levels were significantly down compared to the mid panels. Nothing about the response of that model looked anything like the MMG's that I had in here a few months ago.
And I don't see a lot of high praise being bestowed on a speaker with internals at this level of quality (or lack there of).
(http://www.indiespinzone.com/mag/17a.jpg)
I honestly can't look at that and say to myself that these guys really know what they are doing.
They make some nice panels though and I believe that it is not hard to take them up the performance ladder by a LOT and in many areas.
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Just because you don't know what it is, doesn't mean they don't have an acoustical target. :)
The praise for this speaker comes from listeners/owners/reviewers that probably haven't seen the internals, nor would they care what they looked like.
Clearly Magnepan doesn't prioritize component selection and workmanship in the same way you do, but that doesn't necessarily mean they don't know what they're doing.
I've listened to a set of 1.7's extensively in a nice room. For what they are, they're excellent speakers....stock.
Dave.
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What I mean by saying I don't know what their acoustic target is comes from measuring various models and seeing no real pattern at all. It looks to me that they design them from an electrical standpoint rather than any acoustic response.
And anyone that is interesting in improving them is going to to have a look inside. And anyone with any experience with speakers will recognize a lot of room for improvement in that department.
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Everything on the Magnestand website of a technical nature is highly suspect. Peter Gunn (John) himself doesn't even know what a crossover is, so I would take everything there with a grain of salt.
The newer X.7 speakers are all series crossovers. You guys are aware of this, yes? I keep somewhat informed on the modification activities of Magnepan users but I have seen no schematic drawings of these newer speakers that I would 100% believe are correct. Magnepan is no longer supplying schematic diagrams for their current models, unfortunately.
Regardless, if you want to really improve those speakers you need to remove the whole stock crossover and reconfigure the setup for bi(tri)-amp operation. Anything else is just turd polishing. If this is beyond the capabilities of any contributors, I think I would be inclined to just leave well enough alone.
Dave.
Dave, is that your pair of Eminent Technology LFT-8b's for sale on U.S. Audiomart right now? IMO a better speaker than the MG 1.7i, and at a price cheaper than new 1.7's. The LFT-8 comes from the factory bi-ampable, unlike the 1.7.
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Just curious, what is it that you do not like about the 1.7i's? I own the 1.6's and MMG's and have heard the 1.7's. 3.6's, 3.7 and 3.7i's. Maggies are finicky about amps and preamps as well as positioning. They like lots of high current power.
I use to run my 1.6's with a Parasound A21 and an AVA hybrid tube preamp. They sounded good but not great, but when I went to a Pass Labs X250 amp and a BAT preamp they really came alive and sounded so different.
Also, adding a high quality subwoofer makes a huge difference.
The GR Research OB/Dipole Subwoofer is THE sub for the 1.7, as well as all other dipole loudspeakers.
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Dave, is that your pair of Eminent Technology LFT-8b's for sale on U.S. Audiomart right now?
Yes. In fact, those are improved from stock since I addressed the HF resonance of the woofer driver by modifying the network. The ET's are better than Magnepan's in some ways, but fall short in others. However, I could live with either speaker long term.
Dave.
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What I mean by saying I don't know what their acoustic target is comes from measuring various models and seeing no real pattern at all. It looks to me that they design them from an electrical standpoint rather than any acoustic response.
Nope, I think the opposite is closer to reality. In fact, the majority of the Magnepan models have electrical design that have no relation to any kind of targeted response. The raw acoustic response of the drivers themselves completely eliminates that (possible) approach.
If you'd like to see some designs from an electrical standpoint rather than an acoustic response, take a look at the Magnestand efforts. :)
Dave.
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I hear you Davey, but having measured a handful of them and seen measurements on several others I find myself having a hard time believing that a humped up response, or a response with a rolled off top end, or a response with a thin or falling lower range (responses that are all over the place) are somehow desired or chosen responses. I just can't see varying the response away from a reference that represents some level of accuracy to some abstracted response because it will sound better that way. And the quality level of the components used does not suggest to me that a lot of time was spent in their selection. So why would I believe that a lot of time and effort was put into designing an acoustic response that varies so much from a typically desired level of accuracy?
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And in regards to this comment:
Regardless, if you want to really improve those speakers you need to remove the whole stock crossover and reconfigure the setup for bi(tri)-amp operation. Anything else is just turd polishing. If this is beyond the capabilities of any contributors, I think I would be inclined to just leave well enough alone.
As you know many of these designs use a series crossover. So re-configuring them for bi-wiring or tri-wiring would require designing a new crossover. Plus, just using multiple amps to drive these verses a single amp is not much more than a drop in the bucket compared to a lot of other things that can be done to them. And just because you don't understand something does not make it turd polishing. Feel free to contribute here Davey, but don't disparage others from their quest to make things sound better.
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And lastly, I'll respond to this one.
No doubt you would find these speakers would not measure acoustically flat and would not conform to some idealistic response curve you had in mind. However, that's essentially irrelevant because we don't know what acoustical target the Magnepan guys had in mind.
It is naive to think that because something is messed up that it is supposed to be messed up, and that a shift in frequency response or tonal balance back to a higher level of accuracy would some how sound worse.
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Danny,
Now you're resorting to straw man arguments.
I made no mention of a measured and/or targeted response that is "messed up." I'm simply saying that Magnepan is probably designing to an objective that neither you or I understand. (That shouldn't be a difficult premise to grasp.)
Your assumption is that a shift in tonal balance to a "higher level of accuracy" would sound better? That's speculative and assumes that you know what a "higher level of accuracy" is relative to the folks at Magnepan designing these particular speakers. "Accuracy" is more than objective in the crazy world of speaker design. You should well know that. :)
Regards switching the configuration: Again, you've created an argument against something that I didn't say. I said nothing about bi-wiring or tri-wiring with some sort of passive bi-amping scheme. I would agree that is a drop in the bucket.
I was referring to a complete reconfiguration to a line-level crossover with power amplifier bandwidth limiting and all the other benefits that approach entails. I've done this many times with Magnepan speakers so I know of what I speak.
My turd-polishing comment is accurate. Whether you believe it or find it disparaging is your point of view....not mine. :)
Cheers,
Dave.
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I made no mention of a measured and/or targeted response that is "messed up." I'm simply saying that Magnepan is probably designing to an objective that neither you or I understand. (That shouldn't be a difficult premise to grasp.)
Your assumption is that a shift in tonal balance to a "higher level of accuracy" would sound better? That's speculative and assumes that you know what a "higher level of accuracy" is relative to the folks at Magnepan designing these particular speakers. "Accuracy" is more than objective in the crazy world of speaker design. You should well know that. :)
My comment regarding messed up refers to a response curve that is not accurate.
In a way you are right about them possibly having a design objective that we don't understand as I find it hard to understand why a more accurate response wouldn't be desired especially since adjusting the response to produce a more accurate output level is so easy.
And are you suggesting or assuming for some reason that a shift in tonal balance away from accurate would sound better?
And in terms of accuracy, that is pretty simple really. Greater deviations from the input signal is less accurate. Less deviation from the input signal is more accurate. One doesn't have to speculate to understand that.
Regards switching the configuration: Again, you've created an argument against something that I didn't say. I said nothing about bi-wiring or tri-wiring with some sort of passive bi-amping scheme.
Sorry, I meant bi-amping or tri-amping just as you stated. I wrote bi-wiring and bi-amping by mistake.
My turd-polishing comment is accurate. Whether you believe it or find it disparaging is your point of view....not mine. :)
I find your turd polishing point of view to be that of a narrow minded man that won't allow himself to understand the performance gains of higher quality components, wire, connectors, etc. And I typically don't say things like that but the point was not to express my point of view, but to help you understand how such remarks come across. And then what if I said, oh did my point of view poo poo on you? I'm sorry, I still find it to be accurate. If it sounds disparaging then maybe that's just your point of view... I mean really Davey, why poo poo on someone interested in upgrades to their speakers?
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Here is a frequency response graph from Home Theater Shack speaker comparison done in Nov. 2013
It doesn't look that bad, it appears that 1/12 octave smoothing was applied from the boxes checked below the graph.
(http://nicx.com/ClientSets/JBen/magnepan%201.7%20hometheatershack%20nov2013.png)
Scotty
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I have decided to buy Myestands first and then tackle to crossovers a little later.
Tim
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I have decided to buy Myestands first and then tackle to crossovers a little later.
Tim
When you're ready, I'll be glad to help.