Are you sure it's not worth it to fix the Butler? |
Once again I disagree with Atmasphere's oft-repeated assertion. |
^A lower impedance can help; extend frequency response, improve the linearity of frequency response, and as you've already noted can increase dynamic range.
If autoformers were such a panacea, why don't more (any?) speaker manufacturers include them in their products? If not speaker manufacturers, why don't more (any?) cable manufacturers, especially those that like to add such boxes to their products, terminate their offerings with them? I wonder what % of people that have audio gear incorporate autoformers in there systems? I'd hazard a guess that it's quite low.
One letter from one amp manufacturer (even one I respect) that might suggest that his products sound better into higher impedances, does not convince me that pros of higher impedances don't outweigh the cons. IME, I seem to prefer systems with speakers that have lower impedances over those with higher impedances. Now I don't go looking for these things, but a pattern has emerged. With this I can only come to a hypothesis that the distortions you make mention of; are less significant than the other considerations that come into play towards all that makes listening enjoyable. |
Atmasphere, on this very forum speaker builders have suggested that with a lower impedance they can more easily achieve deeper bass response (extended frequency response), a more linear impedance (improve linearity of frequency response)and as you've said a lower impedance can make a speaker play louder (increase dynamic range)(am I really putting words in your mouth?). To that let me add that I've yet to see an impedance plot from a speaker that claims to provide waveform fidelity and can back it up with an appropriate square wave response that doesn't also demonstrate an impedance plot that drops below 8 Ohms. Now any deviation from what the medium can offer with regard to any of the above would be a distortion. We haven't created the perfect speaker or the perfect amplifier for that matter yet, they all come with distortions. Pick your poison. As has been previously posted on this forum that the vast majority of speakers rated and listed in Stereophile as being worthy of their highest Class A rating have lower impedances. It appears that the most successful high end speaker manufacturers make speakers with impedances that drop below the 8 Ohm standard. I suspect that the majority of readers here on Audiogon have speakers that drop below the standard 8 ohms. Do we all like distortion too? As I've already alluded to, I don't go out of my way to find speakers that have lower impedances, it's just that the systems that seem to more totally satisfy me have speakers with lower impedances, regardless of whether or not the amplifiers do or don't have some academic distortions that don't seem to bother me as much as the alternatives. Please pardon me for butchering a cliche', but it comes down to hearing the forest from the trees. |
^Let's start with these links 1st:
"If sound quality is your goal, it will be best served by a speaker that is 8 ohms or more, all other things being equal." If you want greater **sound pressure** there is a slight argument for 4 ohms if you have a transistor amp. IOW, there is no argument in support of four ohm speakers in high end audio.
FWIW these days there is little argument for 4 ohm speakers in high end audio. This because regardless of the amplifier technology (transistor, tube or class D), the amplifier will sound better and perform better on higher impedances. Of course, if you are unconcerned about sound quality, and more interested in sound pressure, than 4 ohm speakers will be more attractive if you also own a solid state amplifier. The other argument against 4 ohms is the speaker cable- they are extremely critical for best results on 4 ohms, while at 16 ohms they are not nearly so. Making a speaker to be higher impedance, all other things being equal, is an easy way to make the speaker appear that it is smoother with greater detail, always a desirable combination.
Atmasphere (Threads | Answers | This Thread)
http://forum.audiogon.com/cgi-bin/fr.pl?
cspkr&1356668050&openusid&zzAtmasphere&4&5#Atmasphere
The point is; speaker designers have to make many considerations when designing speakers and sometimes for the greater good compromises have to be made, and rarely is it so black and white that a design choice is either good or bad. Even what might appear to be a less than ideal choice might actually have some positive attributes.
BTW, I don't agree with your assessment of George either. Like most of us here, he's shared his experience and his points and advice seem to have merit. |
There are many, many speaker cables to choose from. I'm confident that one would find many (if not most) will work just fine with a 4 Ohm load speaker. |
Atamsphere, here's another link:
12-28-09: Audiokinesis
Unsound, obviously I should have
made it clear which part of my
response was about things an owner
of existing speakers could do, and
which referred to something that
would have to be done during the
design stage.
In my opinion using an autoformer is
something a speaker owner would do
to make his speakers more compatible
with OTL amps.
If we're just looking at the design
stage, then yes it is easier to
smooth the impedance curve by
lowering it. But if the end goal is
compatibility with OTL amps, for
example, lowering the impedance
curve can be counter-productive.
Some of the design choices that lead
to a medium to high, and smooth,
impedance curve need to be made
before the crossover design stage.
For example, I can't expect to build
a 2.5-way system using two 8-ohm
6" woofers and end up with an
OTL-friendly design.
Audiokinesis (Threads | Answers |
This Thread
I'll try to find more as my time
permits. |
Atmasphere, I included the quotes as per your request.
The first two from you to support my premise that I wasn't putting words in your mouth.
The ones from Duke (AKA: Audiokinesis) with re: to it being easier to steady an impedance by lowering the impedance (and ergo make for a smoother frequency response).
I'm having trouble with my old memory as to whom might have suggested that lowering the impedance could help with bass response (and ergo increase frequency response), so the search for that link might be considerably more difficult. Then again if we can extrapolate the words from a very articulate, very well respected (especially here on Audiogon) amplifier designer; that one can get greater sound pressure into a 4 Ohm load with a ss amp, then we can use that extrapolation to suggest that as frequency response is measured in dBs, one can extend bass response and therefore extend frequency response.:-) |
Atmasphere, Ah ha, I found one, I'm confident there is at least one more from a different source. I'll keep scratching my head.
04-05-11: Lrsky
Soundlock makes a good point.
Jim Thiel, starting in 1988, while developing the CS5's discovered that, by using bass drivers that drop precipitously in resistance, that this had a side effect of pulling more current from the amplifier--acting 'almost' as an equalizer on the bottom/bass region.
I have not discussed this, but it seems plausible, AND if Jim said it to be true, I don't need much else to bolster this opinion.
So...with that said--an amp with lots of balls, doubling as the impedence drops more and more, as they do get into the 2 ohm region with the THIEL 3.7--should mate well with a 'Krell-like' bass performer. I don't ascribe to the Magtech amp, as I haven't heard it...yet, he's right on the mark in his assessment. THIEL's need current.
As a side note--one very hard earned lesson by Jim that year was, that virtually everyone exaggerated their current delivery on the amplifiers--very few did what the manufacturers claimed.
Good listening...
Larry
Lrsky (Threads | Answers | This Thread) |
Bruce, thank you for your thoughtful response. It's late for me now, I'll try to find time in the near future for a more deserving answer. In the mean time, you might want to reread the chronology of the posts above. I think you'll understand why I ended that post to Atmasphere with a :-). |
Atmasphere, My disagreement was and continues to be with your earlier post(s):
"Now it is a simple fact that there is no good argument for lower impedance (4 Ohms or less) in high end audio; that is to say if **sound quality** is your goal." |
Atmasphere, on the surface, I don't think anyone would argue that reducing distortion would be a good thing. But we have seen when distortion reduction specifically and unto itself with disregard for the whole can cause more harm than good.
From the above; it seems that Steve McCormack's thinks that the autoformers made his amp "happier". Well, I might believe that, but that unto itself doesn't mean a whole lot when considering the whole lot.
There is apparently more to low impedance than just "sound pressure" (I'm not putting words in your mouth, am I?). For many years in the past, and very much in the present, and I'll hazard a guess, that for many years into the foreseeable future there will be speakers with low impedances with high end aspirations. I would caution those considering acquiring loudspeakers not to dismiss loudspeakers that have low impedances. There are many, many superior loudspeakers that might be missed out on. There are many amplifiers capable of driving them just as they come from the factory.
With all due respect, we've going back and forth on this subject for years now. Unless there is a drastic change in the audio landscape; as long as you keep making the assertions:
"Now its a simple fact, that there is no good argument for lower impedance (4 ohms or less) loudspeakers in high end audio; that is to say if sound **quality** is your goal."
I will probably object. In an effort to save time and bandwidth, perhaps we can come to some sort of gentleman's agreement on how to deal with this in the future?
BTW, as I read it; George didn't call you stupid, he called one of your suggestions stupid, and that was after you called him a "troll", which was after he posted a link where he recommend your product. This line of posting is somewhat out of character for you. You're better than that. But, hey, we're all human.
Best Regards,
Unsound. |
http://www.stereophile.com/content/martinlogan-aerius-loudspeaker-measurements-1998 |
^The sensitivity while low, isn't terribly challenging, at least for the earlier model. |
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^Yes, someone should do it immediately, as they might be inadvertently garnering more sales.;-) |
It's only cruel to an amplifier if it's not up to the task. |
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Atmasphere, 04-03-14: "...George keeps pulling the thread off-topic by suggesting that a powerful transistor amp be employed; he also said that my suggestion of the ZERO was 'stupid', and did so without any experience whatsoever with their use...."
Georgelofi, 03-19-14:"...I have Ralph, and I stand by what I said, I have even put them on my system which definitely doesn't need them, and the sound took a big step backward...." |
I could be very wrong or just confusing the Manley with VTL, but I seem to remember that they came with 5 Ohm outputs. Caveat, I seem to remember that my memory was once better, but I could be mistaken about that too.:-) |
Thanks Al. You are too generous, the error was probably all mine.:-) |
Every once in a while I remember to use my memory :-).
One of the speakers used here was the earlier ML Aerius and not the OPs ML Aerius i, nevertheless it might be germane:
http://www.stereophile.com/reference/810/index.html |
"...IOW the ML ESLs are a low impedance Power Paradigm loudspeaker..."
Perhaps I'm missing something here, but do these graphs seem to suggest something else?
http://www.stereophile.com/reference/810/index.html |
Al, thank you. I thought I might have missed something. Still, the last paragraph seems to suggest what I think most could reasonably expect:
"...Figs.5-7 show the measured impedances of the 2Ce, Angelus, and Aerius. Note that the Sonic Frontiers' frequency-response deviations when driving these loudspeakers show the same general trends as the impedance magnitudes of each respective loudspeaker. That is, the peaks and dips in the responses correspond closely to the peaks and dips in the impedance plots. The impedance plot therefore gives a general indication as to just how a given loudspeaker's response will change when used with an amplifier having a high output impedance.—Thomas J. Norton"
Unless there is some sort of internal eq or the impedance actually compensates for the drivers-crossover/speaker systems inherent deviations from flat frequency response (something that has been done to some degree in crossover designs from other manufactures, but something I've yet to hear attributed to ML designs), I'd hazard a guess that it might be reasonable to extrapolate that the sound output to somewhat mimic the impedance/frequency graphs provided. |
Atmasphere, perhaps I'm not seeing the same things you are?
And, Bifwynne's post re: MLs amplifier recommendations seem to suggest amplifier characteristics that are at odds with your post
"...IOW the ML ESLs are a low impedance Power Paradigm loudspeaker." |
