[medium jim]

I probably confused the issue with the use of the word "oomph", when the proper word would have been "weight" to the bass, which planars are capable of producing if given enough panel size/mass.  The issue is that low bass usually dips down to 2ohms and even to 1 in some instances.  Tube amps are adept at handling low ohm loads, but even then, can be taxing.   SS or Class D can compensate for this to some extent with more wattage. 

Jim

[jimdgoulding]

Jarcher, hi.  Just peeped your basement listening room.  Dude, looks like the control center of a futuristic rocket shuttle or something.  Can it fly?

[jarcher]

Jarcher, hi.  Just peeped your basement listening room.  Dude, looks like the control center of a futuristic rocket shuttle or something.  Can it fly?

Thanks - just a life long dream to have a dedicated home theater basement, so finally got to do it a few years back.  Actually did that whole room ground up including all drywall / paint / insulation / lighting (led dimmers) / wiring conduits / carpeting / furniture & custom rack for about $15K.  And that was paying a crew to do it - I unfortunately don't have the skill set.

Reminds me I need to update the photo as I replaced that futon w/ some cheap home theater power recliners.  Those Ikea futons are handy + cheap, but even w/ the best mattresses not that comfortable for sitting. Listening / viewing comfortably is one of the best A/V investments........

[SteveFord]

Thread derailment:
jarcher,
How do you like that Manley Stingray?  I'm thinking about pairing that up with a Mini Maggie system next year. 
Your thoughts? 

[Davey]

The issue is that low bass usually dips down to 2ohms and even to 1 in some instances.  Tube amps are adept at handling low ohm loads, but even then, can be taxing.   SS or Class D can compensate for this to some extent with more wattage. 

Jim

Huh?  Jim, I don't know where you come up with this stuff. 

The DC resistance represents the lowest impedance of a transducer frequency range, but only a very few speakers have impedance's in that low of range.  Apogee Scintilla, Full-range, etc.
Maggies certainly don't.  They're generally at/near 4 ohms throughout their frequency range.  Only the crossover network yields peaks in the system impedance of Magnepan's.

Cheers,

Dave.

[ehider]

Having myself owned two different Maggies, I would absolutely agree with Dave that Maggies do NOT droop in their impedance whatsoever at the lowest frequencies or any other frequencies for that matter (see chart below of 3.6 model's impedance measurement from 10 hz to 50khz).

[jarcher]

Thread derailment:
jarcher,
How do you like that Manley Stingray?  I'm thinking about pairing that up with a Mini Maggie system next year. 
Your thoughts?

I love it, not just for the sound but for the looks as well - it's got that SOCAL hot rod look to it - maybe because Manley's SOCAL? 

It's no slouchy amp - those EL84's have got lot's of jump, and the sound overall is fast and relatively clear for a tube amp. Probably not best for brighter less efficient speakers.  Oddly enough I never tried them w/ Magnepans - the 1.7's because I just figured they wouldn't have enough power, and some MMG's because of placement issues (i.e. MMG's didn't work in my living room). Some day I'm going to have to give it a try with those. It would have no problem w/ a Mini Maggie system........it even has line level sub-out's if you need them.

The Stingray v2, which I A/B'ed w/ my 1st gen, is even better, I think mostly in part to the 4X increased capacitors in the power supply.  I've thought sometimes of modding mine to put those bigger caps. I asked EveAnna Manley & she wouidn't do it, but my tube tech said it was totally doable.

Cosmetically I like the slimmer profile on my first gen vs the second gen one.  But the massive RF remote control of the second gen is super cool - it looks like something used to detonate explosives.  No remote option for 1st gen stingray.

[jarcher]

Having myself owned two different Maggies, I would absolutely agree with Dave that Maggies do NOT droop in their impedance whatsoever at the lowest frequencies or any other frequencies for that matter (see chart below of 3.6 model's impedance measurement from 10 hz to 50khz).

That's been my understanding as well - i.e. that maggies while a 4 ohm load, tend to be a pretty flat 4 ohms across the frequency range, which your chart demonstrates. I.e. they don't have wild impedance swings like some speakers. This sort of refutes claims of massive power needed for maggies.  You just need something that can produce a reasonable & consistent power to a 4 ohm load. More power might give you more headroom - though only as far as the physical constraints of maggies - i.e. mylar / QR / whatever slapping magnets.

Sorry guys - probably shouldn't have brought up the maggie power debate again........

[medium jim]

What I love about Davey is that he is such a curmudgeon

Jim

[medium jim]

That's been my understanding as well - i.e. that maggies while a 4 ohm load, tend to be a pretty flat 4 ohms across the frequency range, which your chart demonstrates. I.e. they don't have wild impedance swings like some speakers. This sort of refutes claims of massive power needed for maggies.  You just need something that can produce a reasonable & consistent power to a 4 ohm load. More power might give you more headroom - though only as far as the physical constraints of maggies - i.e. mylar / QR / whatever slapping magnets.

Sorry guys - probably shouldn't have brought up the maggie power debate again........

Glad you did, as it actually is what I wanted to hear and learn. 

Jim

[Davey]

The magnitude (and flatness) of the Magnepan impedance swings is not really related (directly) to the power requirement.  They DO need a lot (some might say "massive") of power, but it's because of the very low acoustic efficiency of the transducers and not the impedance load.

I've seen some refer to Maggies as an "easy" load for an amplifier.  This is partially true, but only in one context. 

Cheers,

Dave.

[jarcher]

The typical rated efficiency of Maggie's seems to be around 86dB. Not great but doesn't seem very inefficient....

[pansixt]

Jarcher, hi.  Just peeped your basement listening room.  Dude, looks like the control center of a futuristic rocket shuttle or something.  Can it fly?

It Soars Jim. One time I was there and watched and listened to Avatar, the movie. With the FULL Maggie Home Theater effect. It was very enveloping and impressive.
Since then, on occasion, I had the pleasure of experiencing the large vintage tubes power the 1.7's in 2.0 and 2.3 sans pre. Once again, very impressive.
Yes that lady is built.
So come on up to Ole Virginny for the upcoming Mid Atlantic Audio Circle's meet and take a gander pard.
James

[Davey]

Yeah, the 86db figure doesn't seem too bad...at first look...but it's spec'd at 2 watts (vice 1 watt for almost all other speakers.)
So, it's effectively 83db (best case) for a nominal sensitivity rating relative to others.
Here's the point where everybody chimes in and tells me that since they're a line-source and we're listening in the near-field the SPL drop-off is less with distance. 
That's somewhat true, but only for the largest Maggies.

Many conventional systems nowadays are in the 93db/1-watt range.  Remember it takes ten times the power to increase SPL 10db......so you can see where the hunger for power comes from. 

They're just horribly inefficient speakers......there's no two ways about it. 
It's not a criticism.  It's just a given with the trade-offs utilized.

However, I will agree they're more efficient than a pair of Apogee Scintilla's.  If you had small nuclear reactor in your backyard, you'd have just about enough power for those. 

Cheers,

Dave.

[DustyC]

Just a thought. Given the low cost and high power of the class D offerings lately, a small chassis box hung on the back of the 1.7, 3.7, and 20.7 would allow a "powered" maggie with a minimal footprint. No fancy box, just a black chassis hidden away in the back with as much as 1000 watts on tap. The old 20.1 had a large crossover box that sat between the stand rails, double the height of the box and you could add a class d amp in there easy.

[jarcher]

Yeah, the 86db figure doesn't seem too bad...at first look...but it's spec'd at 2 watts (vice 1 watt for almost all other speakers./quote]

Where do you find its 86dB into 2W vs 1W?

[jarcher]

Just a thought. Given the low cost and high power of the class D offerings lately, a small chassis box hung on the back of the 1.7, 3.7, and 20.7 would allow a "powered" maggie with a minimal footprint. No fancy box, just a black chassis hidden away in the back with as much as 1000 watts on tap. The old 20.1 had a large crossover box that sat between the stand rails, double the height of the box and you could add a class d amp in there easy.

I'd prefer to choose my own amp (and subwoofer).  Guess that's why among other reasons I'm a Magnepan owner & not a Martin Logan.  Also not sure that Magnepan could offer that option as well done and economically as a stand alone amp form class D amp manufacturer (e.g. Wyred4sound, etc).

Let's face it folks - I think Magnepan has it more or less figured on their products.  Maybe some day there will be some material improvement they can slap on the mylar that will be a substantial departure (3-way true ribbon - is that even possible?).  Otherwise just refinements to what they have as they become cost effective (e.g. better crossover / better frame it that helps / etc).

They are wise to address the size issue w/ the Mini Maggies though.  I think this more than anything else is their biggest sales obstacle....

[Davey]

Where do you find its 86dB into 2W vs 1W?

It's on the spec sheet for all of the models.
They're cagey about it since they quote 8Xdb/2.83 volts.  But since the speakers are 4 ohms 2.83 volts converts to 2 watts.

Notice also the specs for Tympani's are rated at 10 watts at 6 feet. 

http://www.integracoustics.com/MUG/MUG/articles/speakers.html

Cheers,

Dave.

[TitaniumTroy]

Davey, how much power should my 3.6's be driven with? Currently using a NAD 218THX in a room about 26'x12' 1/2 with a sloped ceiling that goes from about 7' 1/2 to 13" at the peak. Also I listen pretty much at moderate levels most of the time, but do crank them up once in awhile, oh and crossed over at 40hz to an SVS Ultra Plus 2 subwoofer.

Thanks

[Davey]

Troy,

It's difficult to make absolute determinations..........but just run the arithmetic and see.

Start with the 3.6 sensitivity of 85dbSPL @ 1 meter with 2 watts.

The SPL fall-off with distance will be somewhere between 6db and 3db per doubling of distance.  (Assuming 6db is more realistic IMO.)

So, subtract 6db per meter all the way to your listening position.
Add approximately 3db to SPL since you have two speakers.
Add approximately 3db to SPL since your listening room is a reverberant environment and not free-field conditions.

That should yield a pretty good estimate.

I believe you'll find your amplifier is (on paper) more than adequate for the 3.6's. 

Cheers,

Dave.