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In Reply to: RE: Have to take the Lamm M1.1 off my list posted by A.Wayne on December 03, 2014 at 10:18:01
The sweet spot is not at 100 watts...that is the knee where the distortion starts to rise sharply...big difference. You are ignoring the fact that at 100 watts most speakers, even most Apogees are LOUD.
You are wrong about the sensitivity of Apogees as well. Only the original Full Range and Scintilla are so insensitive.
Scintilla data:
Height
147cm
Width
83cm at base tapers to 74cm at top
Depth
9cm
Bass driver
Aluminium/Kapton panel (hand cut)
Midrange
Aluminium
Tweeter
Aluminium (4 x 0.5in wide)
Max Sound Level
110db in a 40sqr meter room, approx. 350sqr ft
Sensitivity @ 3m
79dB
Frequency response
20Hz (-6dB) to 25kHz
Crossover frequencies
500Hz bass to mid, 3kHz mid to tweeter
Suggested amp power
100W (Has to drive 1ohm loads on later models)
Impedance nominal
1 or 4ohms - start of production until 1996/7
1ohm only afterwards
Note that the spec of 79db is at 3 METERS! Now, if that is true then with 2 speakers it is more like 82db at 3 meters.
82 = 1 watt (1 ohm delivery)
85 = 2 watts
88 = 4 watts
91 = 8 watts
94 = 16 watts
97 = 32 watts
100 = 64 watts
103 = 128 watts
106 = 256 watts
Now, assumming the Lamms can put out the same power at 1 ohm as at 2 ohms (I have no doubt that they can) then they will play as loud as you could probably desire without seriously clipping.
The Scintilla is the worst case Apogee by far.
DUetta Signature:
"However, the sensitivity is actually rather higher than with previous Apogees, and a solid 100W per channel will deliver satisfactory sound levels."
"Equated to 3m, the Duetta operates at an approximate sensitivity of 86dBW - a usefully average level. This explains why it is able to deliver a decent 105dBA peak programme for a stereo pair at the listening position - assuming that sufficient amplifier power is available. For comparison, an ARC D125 would provide 100dBA and a Mimesis Three 103dBA."
"Set to 'normal', the impedance plot (Graph 5) gives a most uniform 4 ohms, with a minimum of 3.6 ohms around 2kHz and a maximum of some 5 ohms at 450Hz. No rise of any kind was visible at the bass resonance, and the reactive content is very low."
Diva:
"Height
188 cm
Width
82 cm
Depth
7 cm
Bass driver
Aluminium/Kapton panel (hand cut)
Midrange
Aluminium/Kapton (3 segment)
Tweeter
Aluminium single segment
Max Sound Level
115db SPL @ 4m with 100W amplifier in a 18'x25'x8' room
Sensitivity @ 3m
87dB
Frequency response
25Hz (-3dB) to 25kHz
"
115db at 4m with 100 watt amp (3 ohm capable)
I have a friend who had a diva and 100 watt 4 ohm rated amp drove them very well and to loud levels.
"Which brings us to the impedance: I have now heard the Divas with four different Krell models, the Beard 200W monoblock tube amplifiers, the Primare 928s, the Nestorovic tubes amps, Mondial's Aragon 4004 and the smallest Sumo. Every single one of the non-Krell amplifiers drove these to satisfactory levels in a 7.1 X 7.4 meter room. Now I'm not saying that they're all ideal choices, because the wee Sumo (under �600, too) could easily turn grainy and nasty and run hot with sustained usage or high level demands; I only tried it out of a sense of duty and it increased my admiration for that amplifier."
"When it comes to impedance, the Divas really come through. Apogee has obviously worked hard to make amplifier selection a simple task, and the stigma of the Scintilla requirements is history. The impedance is specified not to exceed 4.5 ohms, and never to dip below 2.6 ohms for the whole 20Hz-20kHz range (fig.2). Welcome news, indeed."
Centaur Major:
"ght
163cm
Width
46cm
Depth
30cm
Bass driver
10" Dynamic cone
Midrange/Tweeter
40" Aluminium/Kapton ribbon (etched 6 segment)
Max Sound Level
110dB
Sensitivity @ 3m
83dB
Frequency response
(-3dB @ 30Hz) to 20kHz
Crossover frequency (electronic)
450Hz
Suggested amp power
100W (into 8 ohms) 200W (into 4 ohms)
Impedance nominal/minimum
6ohms / 4ohms"
Sensitivity and impedance are from Stereophile. Will play more than loud enough with the LAMMs.
Follow Ups:
Cab ,Please ,
Have you ever measured , I have measured and they are not that sensitive, have you measured, No, yet you post this stuff as fact. Anyway, you apparently don't understand the kneeing effect on the sonic structure of an amplifier and worse you think that the lamm is operating in class-a @ 2 ohm at 250 watts. :)
I will suggest you start measuring and stop with the conjecture, less say for argument sakes we use your pie in the sky apogee numbers at 88dB at listening distance, using only 8 watts , add 12-18 db(classical will do 20dB) for peaks will require another 128-512 watts without clipping.
Less say your rotational science is off and it is and the apps only need 16 watts for 88 db( reasonable) it would require 1K in peak power to not clip, now calculate the current necessary to produce 500W or 1KW @ 1 ohm.
Stereophile:
"Unfortunately, 1-ohm capable amplifiers don't grow on test benches. You tend to be restricted to the Adcom GFA-555, Krells, Belles, and Classes. Sending too little power into the Scintilla at 1-ohm makes them sound recessed in the midrange, muted, and lacking in deep bass. The result is all depth and mid-bass, and no presence. Other than the amps I found, I don't know what to tell you. Every amp will be an experiment. Don't go by the amps ability to drive a 1-ohm resistor"
Sounds familiar cab and guess what? all those amps listed are dogs for sonics and no i have heard krells sound fantastic when run this hard, after mods is best and not all.Kessler:Two conductor chains are formed in the aluminium foil, each of 2ohm impedance, which can be connected in parallel to give the 1ohm setting at reference sensitivity. If they are connected in series, this gives the 4ohm setting but with a 6dB loss in voltage-rated sensitivity. Yes, the Scintillas have a very low efficiency. For a 4ohm watt- usual reference is 8ohms - I estimate the sensitivity to be poor at 73dB/W.
Notice estimate and not at 3M, we measured 79db/2.83v@1M years ago in 1 ohm config..
The lamm is not the amp for this job, your Hi-Fi may not be as great as it can and more specifically and pretty obvious to me is what you are really preferring and favoring over the Lamm is the harmonic structure from running all these under powered amplifiers into clipping, obvious you are disliking the sound of the lamm when over driven..
My conclusion ...
Regards..
Edits: 12/03/14
Of course I measure things...I gave you reviews where they were measured as well.
I have a calibrated microphone and SPL meter built into my Behringer DEQ2496 and I have a digital scope and Fluke multi-meter...plus computer based measurement systems.
Please see my review a few years ago on the Piega C2 ltd.
http://www.positive-feedback.com/Issue16/piega.htm
You will see speaker measurements I made for this speaker.
"Anyway, you apparently don't understand the kneeing effect on the sonic structure of an amplifier "
Of course I do, but I also understand that one's sensitvity to distortion decreases with high SPL levels... if you had read Cheever you would know this as well.
"and worse you think that the lamm is operating in class-a @ 2 ohm at 250 watts. :)
"
No, I made it clear that it is NOT operating in Class A at 2 ohms. I said it was operating in Class A at 8 or 4 ohms depending on the settings...Now you are resorting to trying to falsify what I said before?? Sad.
"I will suggest you start measuring and stop with the conjecture"
Been there, done that, got the T-shirt. In my room my Acoustats only dropped by 2 db from just in front of the speaker to the listening position 3.5 meters away...that's right just 2 db drop.
Note that Apogee is giving sensitivty ratings at 3 and 4M distance...line sources and room reflections mean much less drop than with conventional speakers...so this is an effective sensitivity...now add a second speaker and my numbers are realistic enough.
Have you ever owned Apogees or a big electrostat? Seems like you haven't. I and my friends have had Dozens of these kinds of speakers with dozens of different amps...I know what I am talking about and you are the one conjecturing.
My big Acoustats measured, in-room, only +-2db from 200Hz to 15Khz. Below they were affected by room modes and above there was a natural in-room rolloff...I measure ALL My speakers and I know how they behave.
"Less say your rotational science is off and it is and the apps only need 16 watts for 88 db( reasonable) "
A duetta Signature was MEASURED by Martin Colloms to have 86db. A pair at 1 meter gives 89db. Now give they are a nearly flat 4 ohm load this means 2 watts to reach 89db at 1 meter.
Now at 4 meters in a ROOM you will have a drop of maybe 4db with a line source speaker.
So
85 db = 2 watts
88 db = 4 watts
91 db = 8 watts
94 db = 16 watts
97 db = 32 watts
100 db = 64 watts
103 db = 128 watts
106 db = 256 watts
88 dB with 12 - 18 db headroom would be 64 - 256 watts. However, this doesn't account for the fact that with Classical music 88db is not a reasonable average level...it is far lower usually. Rock music at an average 88db will be loud and have not nearly as much dynamic range due to the application of compression. Any way you slice it the Duetta Signatures in a normal room at a normal distance will play at least 100db with a 100 watt 4 ohm capable amp.
Divas will play even louder with the same power because they are actually MORE sensitive than Duetta Signatures...with about the same impedance.
"Stereophile:
"Unfortunately, 1-ohm capable amplifiers don't grow on test benches. You tend to be restricted to the Adcom GFA-555, Krells, Belles, and Classes. Sending too little power into the Scintilla at 1-ohm makes them sound recessed in the midrange, muted, and lacking in deep bass. The result is all depth and mid-bass, and no presence. Other than the amps I found, I don't know what to tell you. Every amp will be an experiment. Don't go by the amps ability to drive a 1-ohm resistor"
"
THis is old and well before the LAMM came on the market. I will quote again:
"The M1.2 Reference is conservatively rated to deliver 110 Watts into 8 and 4 Ohms in pure class A operation (high and low impedance settings, respectively); 220 Watts into 2 Ohms, and 400 Watts into 1 Ohm (low impedance setting), continuous. The M1.2 Reference can drive any known speaker. The harmonic structure remains intact regardless of the speaker load, while the extreme clarity is maintained at all power levels.
"
The same was true for the M1.1.
400 watts into 1 ohm is not sufficient? Whatever...
" Lamm is the harmonic structure from running all these under powered amplifiers into clipping, obvious you "
What a load of nonsense! A) I don't listen at high levels normally and B) Clipping NEVER ever sounds good. All of these amps handle peaks far better than you think and since the average is very low I am quite sure I am not running into trouble...
My Friend had before his Octave monos, had McIntosh MC501s (same system with the THiels we were testing). Those have big relatively accurate power meters. He listens MUCH louder on average than I do (maybe as much as 10db on average louder but that is only a guess). We found that his needles with compressed recordings were not going above a couple of watts. With uncompressed music at loud levels we were PEAKING at around 50 watts (they have a peak hold function) and peak levels well above 100db.
You talking about these,
"
The McIntosh MC501 is unusual for a solid-state amplifier in that it uses an output transformer. This has three separate taps, one each optimized for 8, 4, and 2 ohm speakers. I hooked up my 8 ohm dummy load to the MC501's 8 ohm tap, and, following my usual practice, set the amplifier running at one-third power for one hour, to see how well it would deal with thermal stress. To my surprise, the McIntosh shut itself off after just five minutes—the orange Power Guard LED on the front panel illuminated, and the rear-panel heatsinks were too hot to touch. After the amp had cooled down, it turned itself on again. I tried running it at a lower level, just 30W into 8 ohms. This time it turned itself off after 20 minutes; again, the heatsinks were too hot to touch."
Wouldn't count too much on the meters, did you use the 2 ohm tap..,,
4 ohm tap and they are mostly a Class B amp so clearly they are not heatsinked to have sustained power at 500 watts. JA states clearly that this test maximizes the stress on amps with Class AB (or B) output stages. Since continuous power is not a big deal with music I don't know why you would put this comment here. What's the point?
At idle we found it only uses about 45 watts per monoblock, so clearly mostly Class B.
The meters are ballistic design so they claim something like 80% accurate on peaks. Not perfect but gives a good relative idea.
"The McIntosh's maximum output power depended on the output tap chosen and the load, but when the tap was matched to the load, the amplifier easily exceeded its specified 500W at our 1% THD definition of clipping. The 8 ohm tap delivered no less than 720W into 8 ohms (28.6dBW), for example (fig.4), with similar deliveries into 4 and 2 ohms from their respective taps (figs.5 and 6). Despite the slight increase in source impedance, the MC501's ability to deliver current into the speaker load did increase with the decreasing output transformer tap. The 8 ohm tap was limited to 225W into 2 ohms (17.5dBW), for example, while the 4 ohm tap delivered 1000W (24dBW), the 2 ohm tap 630W (22dBW). "
Plenty of power on tap for almost any conceivable listening in a domestic situation.
Cab,Have one of your friends help you and explain quiescent bias , this may help you understand why the Lamm is not full class-a operation at rated 1% thd into 2 ohm.
Eg:Class a power into 8 - 100watts
Class a power into 4- 50 wattsLamm ups bias and changes voltage with his switchy in an attempt to keep full class a into 4 ohms ,
Class a power into 4 ohm - 100 watt
Class a power into 2 ohm - 50 wattYou see Cabby, you half class a power evertime you half the load.
Painfully obvious you have had the same bad audio experiences all these years and why you hate SS equipment , you favor the softness of how tubes distort when clipped vs SS HARD ending when doing so.
Choosen with wisdom ,sized correctly SS can deliver where toooby amps tend to bloat and spare me another list , you are not the only one with a "list" playing here.
Stick a scope on the scinnies next time out with your big 250watts and 100db listening sessions and advise us little guys as to your discovery ..
So take the Lamm of your list, it has insufficient current to drive the speakers you are listening to and get back to tooby clipping ...
Regards .
Edits: 12/04/14 12/04/14
I don't need it explained...I already told you that I know that it is not Class A into 2 ohms! Not sure how many times I have to tell you that I never claimed the amp was Class A into 2 ohms. I stated CLEARLY that it is Class A into 8 and 4 ohms depending on the switch settings.
"You see Cabby, you half class a power evertime you half the load."
AND we are not talking about Class A power, it is clear that the amps you like are not Class A anyway. It is clear from Stereophile that the TOTAL power avaiable from the LAMM is, as Rolls Royce would say, "adequate" and yes it is in Class AB...that was never in debate so I don't know why you keep trying to twist things around.
No one was ever claiming it has full power into low impedances in Class A, so stop making a strawman out of this...you still have uttely failed to show that the LAMM monos are not capable of driving the speakers in question to suitable levels for judging sound quality.
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