[medium jim]

Inappropriate: in this case low power.

You are not answering the question....power comes in many forms, please elaborate.  Then please explain what you mean by Headroom?  Most good audiophile amps will have ample dynamic headroom for those musical peaks or bursts.

Jim

[medium jim]

Jim I really am not interested in playing patty cake with you. I'd actually prefer if you never ever responded to my posts. Just sayin'. Not that I can't answer.

Not paying patty cake, you made a bold statement and merely asked you to elaborate and explain your reasoning behind it.  It is a misconception that one needs a zillion watts to make Magnepan's sing and to say so is a injustice.   My reasoning behind my posts here is that I was led to believe the same BS, that you need lots of wattage to drive them properly.   This BS and me buying into it led me to selling a pair of 1.6's which was a huge mistake.   

Tube Amplifiers excite Magnepan's better than any amp SS amp I've ever had on them.  Maybe this is why there has been such a long relationship between ARC and Magnepan.  Maybe I should say that you really haven't heard you Maggie's at their best unless you have them being fed with Tube Power, but I won't as each has their own preference.  Just because I don't like them as much with SS than I do with Tubes doesn't mean that someone else will go the other way. 

I agree that if you go the SS or Class D road, you do need a lot of watts per channel.   With Tubes you can get by with a lot less wattage and still get the richness, detail, depth, soundstage, imaging, resolution at both low spl as high. 

I drive my 2.5's with a pair of Marantz Model 9's that are under 100 watts each....I have a pair of subs to drive the bottom 2 octaves, but would anyway so that is a non-sequitur.  If I didn't use subs, I could get by with around 150 watts per channel of tube power.  Just for the record, I've hit them with Bryston's, Parasound's and a tricked out BGW amp with gobs of Wattage, they sound better with tubes to me and I think to many others as well. 

Jim

[SteveFord]

I am back from work.
Please try to remember that we're grown ups.

[Davey]

If some of you fellas would like to take your own measurements of Gunned MMG's, here's what I would recommend:  (this is how I did it, but that's not to say it's the only way.)

Wait for the weather to warm up and take one of your speakers outside on a quiet day in a quiet area.  Find a large hard surface with no obstructions and lay the speaker on its side.  Position your microphone on the ground at least 2 meters away.  (This is a ground plane measurement.)  I like the swept-sine measurement of HolmImpulse, but you could use other testing suites as well.  (MLS-based testing is not required.)

I know this seems a silly and ridiculous exercise to some, but it's one of the simplest and only ways to get consistent (meaningful) measurements with large panel speakers that exclude all listening room effects.  If you have access to an unmodified MMG, you have the luxury of taking two sets of measurements and making a direct comparison.

That said, you can already deduce much of the relative difference between un-modified and Magnestand MMG's just by looking at the electrical responses of the two different crossover networks.  The acoustic measurements allow to confirm but also give you some appreciation for how challenging listening room measurements are for these type of speakers.

Cheers,

Dave.

[jtwrace]

They are just jaw dropping speakers.

I look forward to you hearing more speakers.   

Personally, I like massive amounts of heardroom on speakers from a power standpoint.   

[josh358]

Re the power issue: As 4 ohm speakers, Maggies usually stress a solid state amplifier's current capability rather than its voltage capability, although this of course depends on the amp -- some are designed to be especially capable in the current department. Jim, I agree that, all other things being equal, you can get by with a smaller tube than solid state amp. Tubes have better overload characteristics than solid state and one oft-quoted rule of thumb is that you can get by with half the tube watts.

There was a thread on the planar asylum in which contributors posted measurements of the levels at which people listen to their Maggies and there was tremendous variation, on the order of 30 or 40 dB. This leads to endless arguments about power requirements when really, all anyone is saying is "this is enough power for me." What is clear is that Maggies can *use* a tremendous amount of power -- Satie has 2500 watts on the woofers of his Tympani IV's. Those who want to listen to acoustical music at natural levels -- peaks of 115 or even 120 dB -- will need big mother amps. Most of us listen at lower levels, and can get by with less. But I don't know how many times people have said Maggies don't do loud because they tried pushing the volume with a modest amp.

Amplifier power is one thing in audio that can be arrived at objectively -- measure some peaks with a Radio Shack meter, add 10 dB (to the analog reading, anyway), then plug the sensitivity and listening distance into one of the online tables that have been made for that purpose.  With the larger line source Maggies and a typical listening distance, the 1 meter sensitivity is close enough, you don't need to worry about room gain and distance which will be wrong if the table was generated for boxes. Use the rated RMS power into 4 ohms, the peak headroom will then give you a bit of a safety margin -- how many of us can set playback levels within a dB or so?

[medium jim]

Josh:

You really need to ditch the old analog RS meter and get a new Digital RS meter!  My ears would bleed if I had to listen at anything over 100db at the listening position for any extended periods of time. My listening position is about 8' away from each panel and the C weighted Db levels are an average of 95 or so, the peaks can be as much as 10 Db higher.

Funny thing is that I often listen in triode which is under 50 watts to gain all of the harmonics and still have enough to more than adequately drive my 2.5's and without any sibilance or compression.  As you said, tubes have an abundance of headroom at the ready. 

Another beauty of tubes, they put out the same energy no matter the speaker impedance and typically don't run out of current.

The bottom line is that you can drive your Maggie's with tubes and don't let anyone tell you otherwise.

Jim

[SteveFord]

Davey,
I'm sure that you've done this quite a few time but please humor me and post your measurements if you still have them available.
Thank you.

This could really get off topic but the old how much power do I need question has raised it's head.
Nobody can answer that as how big is your room, how deaf are you, how loud is your average listening volume and what do you listen to would have to be factored into the equation.
From my own personal experiences I've found that for low listening volumes (you can talk over it) I'm using 5-10 WPC, for fairly loud (you can talk really loudly over it - like a typical party atmosphere) it's 50-75 WPC and for drive you out of the room it's 150-200 WPC. 
I never saw above 275 WPC - it was just stupidly loud.
These readings all came from a modified Carver M500-t amplifier which is the last amp I owned that had meters and that was used in my living room with IIIAs.  That was a good amp.

The lovely and knowledgeable Ms. Rambold mentioned that the Tympanis were voiced using ARC 80s, I believe. 
I cleaned out my inbox so please correct me if I remember incorrectly.

It's nice to have power in reserve to prevent clipping but most of the time my amps are just loafing. 

I've often wondered why subwoofers have such massive power output; I think it's mostly for bragging rights and for the few who live to play Space Shuttle takeoff CDs to impress their neighbors.   

One final thought: tubes or SS.  Does it really matter?  Whatever sounds good works.  I had tubes going earlier and now it's SS and they both do the trick for me.

[jimtranr]

The lovely and knowledgeable Ms. Rambold mentioned that the Tympanis were voiced using ARC 80s, I believe.

The Tympani I-C's I bought in 1975 from Garland Audio (where I later worked, from 1977 to 1980) were, as I recall, voiced using ARC D-75's or D-76's.

[SteveFord]

It's hell getting old, the mind is the first thing to go.
The nice part is you don't really notice it.

[medium jim]

The Tympani I-C's I bought in 1975 from Garland Audio (where I later worked, from 1977 to 1980) were, as I recall, voiced using ARC D-75's or D-76's.

Would have been most likely the D-76's.  If I remember correctly, Steely Dan's Countdown to Ecstasy was mixed on two pairs of I-C's and a quad of D-76's.  Donald Fagen noted that it was a glorious system.

Jim

[Emsquare]

I've often wondered why subwoofers have such massive power output; I think it's mostly for bragging rights and for the few who live to play Space Shuttle takeoff CDs to impress their neighbors.   

Multiple reasons. Not the least of which is for marketing purposes. (eg. 300 Watts or 3000 Watts? Hmmm... not that I'm immune to it) But the reason is obvious when you think about it. It's all about moving air on the half cycle. The energy needed to throw a pair of 15" drivers around is vastly different than a pair of 1" domes. F=MA. That sort of thing. The woofer cone/voice coil/support weight will likely be in the ounces and the dome more like grams. And then there's the volume of air being displaced. And the influence of the Fletcher-Munson curve to consider. I can't tell you what the mass is of an MG20 woofer membrane/wire-grid is but ponder how it compares to the ribbon foil element.

Anyway, The physics is different depending on the drivers and enclosures in question. But a good visual aid is to compare a serious woofer coil to one of an itty, bitty tweeter coil and you get the implications of the power requirements.

As  far as the tube vs. SS question goes ... Ya, I incinerated my ten foot pole a long time ago. Someday I'll put it to the test for myself. Till then I am having far too much fun discovering new music to worry about it.

[SteveFord]

Sorry, I knew the answer and you're correct.
It just struck me as absurd to have a 500W Class D amp in a subwoofer when I'm probably never using more than 10-20% of it's capabilities.  It's not hurting anything but it seems kind of silly for my application.
If I was my old upstairs neighbor (The Rapmaster) I'm sure the sub's capabilities would be stretched to it's limit and beyond.

[Emsquare]

Sorry, I knew the answer and you're correct.
It just struck me as absurd to have a 500W Class D amp in a subwoofer when I'm probably never using more than 10-20% of it's capabilities.  It's not hurting anything but it seems kind of silly for my application.
If I was my old upstairs neighbor (The Rapmaster) I'm sure the sub's capabilities would be stretched to it's limit and beyond.

Ah. Understood. You were just writing out loud, so to speak. I do that fairly often. But I get your point. Why have all that amplifier on tap when you are only using a tenth of the capability? I think it is an interesting question but I'd be diverting the point of the thread to banter about this any further, so I'll let it be.

[josh358]

Josh:

You really need to ditch the old analog RS meter and get a new Digital RS meter!  My ears would bleed if I had to listen at anything over 100db at the listening position for any extended periods of time. My listening position is about 8' away from each panel and the C weighted Db levels are an average of 95 or so, the peaks can be as much as 10 Db higher.

Funny thing is that I often listen in triode which is under 50 watts to gain all of the harmonics and still have enough to more than adequately drive my 2.5's and without any sibilance or compression.  As you said, tubes have an abundance of headroom at the ready. 

Another beauty of tubes, they put out the same energy no matter the speaker impedance and typically don't run out of current.

The bottom line is that you can drive your Maggie's with tubes and don't let anyone tell you otherwise.

Jim

Truth is, I don't listen at those levels anymore myself -- now that I'm vintage, I want to preserve my hearing as long as possible, so I watch my levels carefully with that old meter.

Which I hate. Music doesn't sound real to me unless the levels are right.

However, those levels -- 118 dB SPL actually -- are for the loudest peaks of the loudest performances. Mahler, maybe, and certainly jazz (which actually goes up to 127 dB. Or if you're right on top of the instruments -- a concert grand, forex, does 120 dB peaks. For most classical performances, 115 dB peaks are adequate (though still louder than I listen these days), and even that's at the high end. So very few of the things I listen to would require those levels even if I didn't use the meter.

Rock performances can get up to 129 dB or so, maybe less today, owing to OSHA regulations. But you'd have to be nuts to listen to subject your ears to that, whatever your age. Not that I should talk -- I remember the youthful me leaving too many concerts with my ears ringing, a sure sign of incremental hearing damage.

Anyway, this is why I think all the arguments about what size amplifier you need are beside the point. People listen at different levels. The size of the amp you need is the size that's right for the levels you listen at! So Morricab's three watt amp is isn't going to work for Satie, and Satie's 10,000 watt amp isn't going to work for Morricab. Different needs.

[josh358]

Davey,
I'm sure that you've done this quite a few time but please humor me and post your measurements if you still have them available.
Thank you.

This could really get off topic but the old how much power do I need question has raised it's head.
Nobody can answer that as how big is your room, how deaf are you, how loud is your average listening volume and what do you listen to would have to be factored into the equation.
From my own personal experiences I've found that for low listening volumes (you can talk over it) I'm using 5-10 WPC, for fairly loud (you can talk really loudly over it - like a typical party atmosphere) it's 50-75 WPC and for drive you out of the room it's 150-200 WPC. 
I never saw above 275 WPC - it was just stupidly loud.
These readings all came from a modified Carver M500-t amplifier which is the last amp I owned that had meters and that was used in my living room with IIIAs.  That was a good amp.

The lovely and knowledgeable Ms. Rambold mentioned that the Tympanis were voiced using ARC 80s, I believe. 
I cleaned out my inbox so please correct me if I remember incorrectly.

It's nice to have power in reserve to prevent clipping but most of the time my amps are just loafing. 

I've often wondered why subwoofers have such massive power output; I think it's mostly for bragging rights and for the few who live to play Space Shuttle takeoff CDs to impress their neighbors.   

One final thought: tubes or SS.  Does it really matter?  Whatever sounds good works.  I had tubes going earlier and now it's SS and they both do the trick for me.

Most meters are averaging rather than peak meters, so you have to add a nominal 10 dB to get the actual peak power figures. This discrepancy causes endless confusion.

It's also true that amplifier size doesn't really affect how loudly a system can play. That's because the ear determines loudness on the basis of average rather than short-term peak levels -- the dynamics of VU meters were chosen to emulate the ear's reaction to loudness, so that engineers could use them to match levels subjectively. And acoustical instruments have a peak-average ratio of 10-20 dB, a factor of 10-100 times in power. So what happens with an undersized amp is that you start to get peak clipping, rather than constraints in how loud the sound is.

it's also true that the ear's subjective response to loudness is logarithmic rather than linear. What this means is that a sound has to be 10 times/10 dB louder to sound twice as loud. A 1000 watt amp can play only twice as loud as a 100 watt one.

Also tube amps have more peak reserve and since practical listening levels are determined by peak levels, you need only half the tube watts as solid state watts to play at a certain level. Back in the day, the D-76/Tympani combo was pretty much state of the art. I listened happily to my 1-D's with a Hafler DH-220 for years, even at fuse-blowing levels. But they'll definitely make use of the extra peak headroom if you give them more power.

Many subs I suspect are rather inefficient, since there's a tradeoff between enclosure size, bass extension, and efficiency. People also want to use them with home theater, for dinosaur footfalls and the like, so need more power than they would for music alone. Then too, equalization is almost a must with subs and even a 3 dB boost will double your power requirements. Also, Class D amps work great with subs, making megapower amps cheap and lightweight, so I think that except in the case of the cheaper models manufacturers design their subs to be limited by driver Xmax rather than amplifier power.

EDIT -- Just read Emsquared's post and I'm sure he's right about marketing as well. I'm such a naif . . .

[SteveFord]

You remember Bob Carver's launch of Sunfire with the subwoofer - world's most powerful subwoofer or something like that out of a small enclosure.  It created headlines and launched a successful company.
Before that, when he was invited to leave Phase Linear he launched the Carver Corp. by making a 100 WPC amp in a Folger's coffee can.  Big numbers in small packages are very impressive and garner the headlines and the investment capital.
A lot of it seems kind of silly but that's what sells.

[JoshK]

Excellent post(s) Josh!   I had to ponder the statement that tube amps have more power reserve than SS amps.  At first, I questioned it, but I think I understand your point now.   Certainly tube amps do not clip the same way and measuring their max power, i.e. clip point typically has to be done at some objective level, when in fact they don't really objectively have a level in which they "clip".   So yeah, they have more power on reserve, just at a raised THD level.  A sort of compression like effect.

[medium jim]

Exactly...that is why I noted that I can achieve spl's that are rather loud without any "compression".  SS amps need to have ample power to avoid clipping as SS amps have a square sinewave at the clipping point which equates to very ugly sound.

Jim

[Emsquare]

EDIT -- Just read Emsquared's post and I'm sure he's right about marketing as well. I'm such a naif . . .

Emsquare(d)? Ow... Josh, buddy. I vaguely regret using that moniker. I had to call myself something though. That's OK. Still enjoy reading your thoughts as I pick out some nuggets of knowledge when I recognize them. Hope your holidays were particularly good to you.

Signing off now. I have a date with the new Regina Spektor stuff I recently acquired. And a bottle of Bushmills 10 year old single malt. Wheee ...

"On the radio, uh oh"