Question about amplification for new Magnepan LRS speakers

[RayDunzl]

Magnepan rates the sensitivity of their speakers with 2 watts input vice 1 watt

2.83Vrms =

1W across 8 ohms
2W across 4 ohms

 

[digicidal]

Not surprising that it measures differently than spec'd considering there is no indication of distance only frequency (500Hz) in the Magnepan specs page. Although we can assume they're saying "@1 Meter" because that's a standard... it doesn't actually say that - it might be .5m for all we know.

However, if it is 80db@1m (which I would trust over the marketing at least)... then 100W is only going to be good for ~89db peaks at ~2.5m. Or am I doing something wrong?
Used the calculator here: Crown calculators.

Room reinforcement isn't calculated in, and I didn't adjust amp headroom - but even with some room gain... it's definitely 'thirsty' if you like to listen at any significant volume and have a large-ish room.

 

[Deleted member 2944]

2.83Vrms =

1W across 8 ohms
2W across 4 ohms

Yeah, that's what I said.

Regardless, Magnepan has always played very fast and loose with the sensitivity specifications on their speakers.
It's easier to just think of them as "not very efficient" speakers. You need a good bit of power AND the speakers will start to exhibit significant compression when pushed.

Dave.

 

[digicidal]

Regardless, Magnepan has always played very fast and loose with the sensitivity specifications on their speakers.

And I wouldn't expect that to change until the day they release their own dedicated amplification. Just saying 'they need plenty of power' is 100 times more palatable (read 'saleable') than 'this particular panel only sounds best with X watts at a distance of exactly Y meters in a room of Z size'.

 

[David Harper]

I read (somewhere) that the Schiit Vidar amp drives the maggie LRS very well, for only 700 bucks. I think it's a high-current amp. 100 wattspc into 8 ohms and 200 wattspc into 4 ohms. Having just received my maggie LRS speakers I just ordered the Schiit amp. Will post the result after listening. I've been driving the new maggies with a Yammy AVR. 95wpc into 8 ohms. The sound is ok but underwhelming. At anything more than medium volume the Yammy gets hot and the sound gets distorted(I'm guessing the AVR is running out of current). The Yammy shut down once. Can't wait to try out the Vidar.

 

[Deleted member 2944]

You are probably thinking of the Steve Guttenberg evaluation of the LRS/Vidar combination.
I suspect that combination will work fine......and much better than your AVR setup.

It would be nice to see Amir add the Vidar amp to his tested collection.

Dave.

 

[David Harper]

drove to the fedex facility last night and picked up my new Schiit Vidar amp. By the time I got home with it I was so tired and wasted I just left it on the floor and went to bed. Got up this morning and connected it into my system. The difference was immediately apparent. The maggies came to life!!! The Yammy AVR was almost too hot to touch driving the Maggies. The new amp is barely getting warm. And the maggies now have bass! (they had almost none with the AVR). More three-dimensional, more power, more volume. And is this new amp heavy! It's small but when you pick it up it feels like a block of steel.

 

[Doodski]

I hope it isn't a breach of etiquette to post several questions about the system I am trying to set up! I appreciate everyone's help! Thought this might be of general interest, as well. From Magnepan website:

The LRS (Little Ribbon Speaker) is a full-range quasi-ribbon speaker that was designed from the ground up to give you a pretty good idea what to expect from the 20.7 or 30.7. The LRS was designed using high-end electronics and mono blocks. The LRS will perform nicely with a receiver, but it was intentionally designed to extract the most from high-end amplifiers and electronics. The LRS expects more from a properly designed high-current amplifier. That is a radical departure from most entry-level loudspeakers. If you put your expensive high-end amplifier on the LRS, you will hear the difference.

So far, these speakers, playing Amazon Music streaming --> Oppo HA-2 DAC--> Cambridge Audio AM-10 Topaz Integrated, sound good but fairly anemic. Does anyone have any idea what "high-end amplifiers and electronics" actually means? In a world where $250,000 amplifiers and $75,000 CD players exist, it is hard to figure what price they consider "high-end". Thanks again!

By the way, I am a guitar teacher, so if there are any questions I can answer about the one thing I do know about, just ask!

A suggestion if you need a better amp and pre... ebay.com has some really nice near linear Kinergetics Class A(to 75 w/ch) amplifiers in anodized platinum green. The price is exceptional for what they are and the sound is superb. I used to provide warranty service for Kinergetics and I can easily testify that they are exceptional units.

 

[Deacon Blues]

Will a NAD 356BEE cut it for these? I'm afraid that 80 watts won't. Even though I only listen at modest volumes.

 

[BogdanR]

Let me get this out of the way first and come completely clean: I love planar speakers. Or electrostats. I heard a pair of MLs in my youth and I was hopelessly hooked. I’ve been owning a pair of 2.6R Maggies for 20 years since I happened upon them on the used gear floor of a local dealer; they needed some love and they were priced accordingly low. Swiped them for CAD 1000 and had them professionally “renewed“ (brand new ribbon tweeters, wiring on the bass panel, etc) for another CAD 400 around 5 years ago.

Maggies are not for everyone, no matter what their marketing says. It is a pretty special kind of speaker, you either love it or it leaves you completely cold.

This is my experience with my pair, all subjective.

First, this particular pair I own are incredibly well built and deceptively heavy. They may be a mere inch thick overall but they are wide and tall buggers. They are obviously dipoles so they are incredibly fussy with placement if one wants to get them to sound right, so at the end of the interminable futzing with them, both your ears and your back will thank you. Make no mistake, if they are positioned right they are incredible. If they are positioned well, they are quite good. If they are not, they sound clear but rather thin and “diffuse”. The quality of their sound therefore is highly depending on positioning. For instance, before finishing our basement, I was pretty much free to position them anywhere I wanted and eventually, by pure luck alone, managed to also hook them on one of the bass nodes of that big “room”. I ended up with them exactly 2.75 m apart, ribbons in, toed in so their axis was just ahead of my listening position which was 3m from them and 1.5 m away from the (long) back wall, which I covered using some old quilts. It all looked like sh.t but the sound I was getting was glorious, including deep, clean, articulated, shirt fluttering bass, not to mention all the ear candy usually delivered by planar speakers when they are set right, so much of it one can go diabetic from the exposure. Fast forward 15 years and currently, in my finished basement where we moved our main entertainment room, they sit closer together (1.8m) and closer to the (short) back wall (.9m) flanking the TV. The acoustics of the room have obviously changed dramatically and the Maggies placement also had to follow aesthetics constraints. Needless to say, I cannot get the same glorious sound anymore. I managed to get them to sound really good within the new constraints, no complaints but I KNOW they can do better. Significantly better. Everyone in my household does know that (for better or for worse). Long story short, placement is critical, more so than with any other regular speaker.

Amplification is also paramount. I second the opinion expressed here (and elsewhere) that Maggies are not particularly hard to drive but they are terribly inefficient. Their membranes don’t have to move much to get the sound going but they are BIG in surface and while the membrane is thin and light, it has the wires glued on, so it takes quite a bit of juice to move as you can imagine. I was driving them initially with a vintage AU999 Sansui. It was... ummm.... OK-ish... but not quite. The Sansui is a great classic which has no issues driving regular speakers but with the Maggies she was struggling. In the end I got a used Rotel RB980 which provided the ample power needed.

There’s a corollary here worth mentioning. At low levels Maggies are weak. Period. At moderate levels they start coming back to life and continue to sound good until they are pushed too hard, at which point the membrane might start hitting the magnets (not good) or blow the fuses if so equipped. They are not party animals. Oh, and I keep 2A fuses handy should any of my friends feel compelled to push the volume too high. It happened. One thing to note, before they crumble suddenly, Maggies maintain an incredible drive, clarity and coherence so one will never have a fair warning of what’s about to happen, mind you they do withstand abuse and recover gracefully. They just don’t like to be pushed. So, far from engaging at low levels and not exactly cooperating at high levels.

Another thing Maggies don’t like is too dry or too humid conditions. I’m not sure that’s still the case with newer models as materials, especially glues are much better nowadays, but on older ones, the wiring has a tendency to delaminate from the membrane as the glue either dries or absorbs moisture and loses strength. It is not expensive to fix them but...

Let me see... is there anything else? ... Oh, if you have a cat, do spray your speakers with repellent just in case. I have two cats. One mercifully ignored my Maggies but took the ONLY opportunity she had to climb on my turntable and chew on my priceless, delicate Ortofon MC cartridge I used to have. The other cat, the younger one, took to to the Maggies, but I caught up with her before she managed to do any damage. Needless to say, everything that involves audio equipment or cables is now sprayed with repellant.

So, Maggies, right? Particularly fussy with placement, amplification and environment. Kind of like one of those girlfriends, great gal, reliable, faithful and loving but a bit temperamental. They require a lot of love and a long time commitment for a successful relationship.

 

[David Harper]

Just got my new maggie LRS speakers. Everything you say is my experience exactly. I have a Yammy Avr but I bought a new Schiit Vidar amp just for the maggies. My LRS speakers are smaller than yours so I needed a good powered sub my speakers only go down to 50hz. The highs are the best I ever heard with the maggies. They won't play as loud as what I'm used to but that's OK the sound quality is well worth the tradeoff. Also the maggies are very intolerant of low-quality mp3 music. It sounds like sh!t. High quality source material sounds amazing. Also I love the dipole sound. It gives the music a sense of air and space like I've never heard before. My kitty has ignored them completely so far but I made covers for them out of the original cardboard packing they came in which I slip over them when I leave the house just in case. They do take some getting used to. They're a trade-off; sound quality vs. power and volume. My old Polk floorstanders were capable of awesome volume and power. But I like the maggies better. They've got me listening to music I never listened to before because they make you seek out high quality source material. Most rock and metal sounds like overly compressed crap and the maggies really reveal this. I've been listening to Radio Paradise on internet radio. Some of the best music I ever heard.

 

[Cahudson42]

Sanity check and opinions for LRS amp: Vidar vs. RX-596..

Looking at the Vidar AP info vs. Amir's review of the RX-596, it seems to me, in so far as delivering clean maximum power (disregarding continuous disappating capability) - not much, if anything would be gained by purchasing a Vidar to replace the 596..

4ohm stereo power graph for Vidar shows 20v, maybe 24v for .01%/80db, so 100w to maybe 150w. (Spec says 200w, but 20v @ 4 ohm = 5A, Power = 5x5x4 = 100w..What am I missing?)

Amir shows for 596 4ohm at least 100w with at least 80db SINAD to 130w, more like 85/.005.. when less..

So, can anyone provide reasons/justification for me to spend $700 for the Vidar? What would "get better"? Vidar df better? Didn't see it..(Have a nice, working RX-596 already)..

Thanks for your advice and opinions!

 

[Wes]

the amp needs to deliver a good amount of current at 4 ohms (for most Magnepans - dunno re LRS)

 

[David Harper]

Sanity check and opinions for LRS amp: Vidar vs. RX-596..

Looking at the Vidar AP info vs. Amir's review of the RX-596, it seems to me, in so far as delivering clean maximum power (disregarding continuous disappating capability) - not much, if anything would be gained by purchasing a Vidar to replace the 596..

4ohm stereo power graph for Vidar shows 20v, maybe 24v for .01%/80db, so 100w to maybe 150w. (Spec says 200w, but 20v @ 4 ohm = 5A, Power = 5x5x4 = 100w..What am I missing?)

Amir shows for 596 4ohm at least 100w with at least 80db SINAD to 130w, more like 85/.005.. when less..

So, can anyone provide reasons/justification for me to spend $700 for the Vidar? What would "get better"? Vidar df better? Didn't see it..(Have a nice, working RX-596 already)..

Thanks for your advice and opinions!

you may be right. I don't notice a big difference between my Yammy Aventage AVR and the vidar amp driving the maggies.

 

[BogdanR]

If the impedance curve of a said speaker would be flat then yes, a certain amount of volts is that amount of power over the whole frequency spectrum the speaker amp combo is capable of reproducing. But almost invariably the impedance curve of speakers is anything but flat. My Maggies R2.6 don’t present a particularly torturous impedance curve but they do dip slightly below 4 ohms over 1kHz. To maintain the same power over that region, the amp needs to be able to deliver more amps. So, the overall current capability of an amp, especially on low impedances is extremely important. Plus Maggies are inherently inefficient so more “juice” is needed to drive them even to normal levels.

Essentially, due to the inefficiency you need more power to drive them and due to the impedance curve, the amp needs to be able to supply the necessary amps to sustain that power level over the regions the impedance drops below spec.

Hopefully the above makes sense.

 

[David Harper]

If the impedance curve of a said speaker would be flat then yes, a certain amount of volts is that amount of power over the whole frequency spectrum the speaker amp combo is capable of reproducing. But almost invariably the impedance curve of speakers is anything but flat. My Maggies R2.6 don’t present a particularly torturous impedance curve but they do dip slightly below 4 ohms over 1kHz. To maintain the same power over that region, the amp needs to be able to deliver more amps. So, the overall current capability of an amp, especially on low impedances is extremely important. Plus Maggies are inherently inefficient so more “juice” is needed to drive them even to normal levels.

Essentially, due to the inefficiency you need more power to drive them and due to the impedance curve, the amp needs to be able to supply the necessary amps to sustain that power level over the regions the impedance drops below spec.

Hopefully the above makes sense.

I saw an impedance graph for the maggie LRS that had the impedance dipping down to close to 2 ohms in the high frequencies. I'm driving mine with a Vidar amp and if I push the volume the amp overheats and shuts down. But it is capable adequate volume. The Vidar is rated at 100wpc into 8 ohms and 200wpc into 4 ohms.

 

[Deleted member 2944]

The LRS impedance trace is essentially 4 ohms across the full frequency range. You're probably thinking of the 1.7 regarding the 2 ohm impedance. That speaker (1.7) has a super-tweeter scheme on the top end and it does drop low in impedance.

LRS measurement from JA:
https://www.stereophile.com/content/magnepan-lrs-loudspeaker-measurements

Dave.

 

[BogdanR]

I saw an impedance graph for the maggie LRS that had the impedance dipping down to close to 2 ohms in the high frequencies. I'm driving mine with a Vidar amp and if I push the volume the amp overheats and shuts down. But it is capable adequate volume. The Vidar is rated at 100wpc into 8 ohms and 200wpc into 4 ohms.

According to JA measurements the impedance curve doesn’t drop much past 3 ohm anywhere, but it does stay underneath 4 ohms pretty much everywhere else. It also looks like a pretty benign resistive load which means the speaker should present a relatively straightforward load to any amplifier. That amplifier however needs a good reserve of current. I’m not sure what Vidar’s current capabilities are but the fact that its thermal protection gets triggered it means it cannot deliver enough of it to play your Maggies loud.

 

[David Harper]

According to JA measurements the impedance curve doesn’t drop much past 3 ohm anywhere, but it does stay underneath 4 ohms pretty much everywhere else. It also looks like a pretty benign resistive load which means the speaker should present a relatively straightforward load to any amplifier. That amplifier however needs a good reserve of current. I’m not sure what Vidar’s current capabilities are but the fact that its thermal protection gets triggered it means it cannot deliver enough current to play your Maggies loud.

It plays them loud enough for 95% of normal listening. Only if I really crank it does the amp have a problem. I've read about the LRS on a lot of forum threads and the general consensus is they don't play real loud no matter what the amplification. It's not what they're designed for. Also one man's definition of "loud" may be different from anothers. When I have guests they often ask me to turn it down a little it's too loud for them. But not for me. The Vidar is a high-current design but it has a microprocessor controlled protection circuit so who knows what the specific reason is it's shutting down. It takes into account three or four different things (over temp./over current/high DC offset). The upside is the amp is almost impossible to damage. The maggie impedance drops to 2.8 ohms between 400 and 600 hz. In any case I would rather the amp shut down than smoke and fry.

maggie impedance-; stereophile.com/content/magnepan-lrs-loudspeaker-measurements

 

[BogdanR]

It plays them loud enough for 95% of normal listening. Only if I really crank it does the amp have a problem. I've read about the LRS on a lot of forum threads and the general consensus is they don't play real loud no matter what the amplification. It's not what they're designed for. Also one man's definition of "loud" may be different from anothers. When I have guests they often ask me to turn it down a little it's too loud for them. But not for me. The Vidar is a high-current design but it has a microprocessor controlled protection circuit so who knows what the specific reason is it's shutting down. It takes into account three or four different things (over temp./over current/high DC offset). The upside is the amp is almost impossible to damage. The maggie impedance drops to 2.8 ohms between 400 and 600 hz. In any case I would rather the amp shut down than smoke and fry.

maggie impedance-; stereophile.com/content/magnepan-lrs-loudspeaker-measurements

The old Rotel driving my Maggies might not pass muster here with ”only” 0.03% THD at its continuous power rated output but its current capabilities in low impedance loads is pretty awesome, 80A on 1 10 microsec pulse, 0.1 ohms (almost like shorted output). Needless to say, the only thing I’m blowing when I turn up the volume more than my ears can take is the Maggies 2.5A fuses. The amp is pretty much unperturbed. Every time I’m tempted to upgrade my end amplification (monoblocks perhaps?) I’m reminded that I have good, clean power aplenty already. The fact I only paid $350 for it, just because it had the tiniest scratch on its faceplate is a bonus.