The two most common mistakes are bass and treble

To Atmasphere: I’m on my third pair of low impedance, super-inefficient Magnepans. I’ve had many other brands of speakers - Altec, Allison, Advent, AR, B&W, Definitive Technology, Elac, KLH, Klipsch, and Wharfdale.
In my opinion, Magnepans are the most neutral speakers made, as well as fantastic bargains.

You can imagine with Manapan in my town and being on a first name basis with the owners (one of them called me last summer when my stolen bicycle turned up on Offerup, for which I am grateful) that I’ve heard them a lot . ’Some of my best friends own them’ although a trope is actually also true. They are good speakers no doubt. Imagine though what they might sound like if higher impedance: They would be less sensitive to speaker cables. The amps playing them would have less distortion. In a nutshell, you’d experience more impact in the bass (owing to the speaker cables not robbing you of impact) and smoother, more detailed sound through the mids and highs (owing to lower distortion from the amps).

I think @erik_squires is correct that planars suffer less thermal compression than lower efficiency cone drivers.

In my collection, my best speakers are not the high efficiency Audio Note AN-e or my DIY single driver using an Audio Nirvana driver, they are my Spendor 1/2e, Quad ESL, Acoustat Model 2, and Analysis Audio Omega. None of which should be confused with high efficiency.

@clio09 Its always important to be careful about conflating personal anecdote with how things are: just because you have one efficient speaker that is bested by others of lessor efficiency does not mean that what I’m saying is incorrect. I have a similar anecdote- a set of desktop Coral loudspeakers that I bought at a garage sale for $5; they are 98dB but sound pretty mediocre; the cabinets resonate and they lack definition and bandwidth, entirely because they simply weren’t built to be anything other than cheap. Obviously the Audio Notes are not that but you get my point.


The Quads and Acoustats are not as inefficient as they appear on paper; generally speaking add 6dB to any planar’s measured values to sort out where they actually sit (some amps have trouble driving ESLs which is unrelated to their efficiency). This is because when measured, the microphone is placed at 1 meter. At that distance, a good deal of the output of the speaker is not picked up by the mic. You have be back from the speaker a good 10 feet to really understand its efficiency. ESLs do not suffer thermal compression as they have no voice coils.


Efficiency and impedance are important, but like class A vs AB in amplifiers, a lot has to do with execution. As an amplifier manufacturer that makes both class A tube amps and class D amplifiers, I see how distortion plays out in systems all the time. In solid state, you lose power as the impedance is increased but you also lose distortion. Now if sound quality is your goal then your amplifier dollar will be best served be a speaker of higher impedance; if *sound pressure* is your goal then you have a weak (3dB) argument for 4 ohms.


Higher efficiency speakers require greater precision in their construction, which makes them a lot more expensive. They were the only game in town when tubes were King; speakers had to make the most of amplifiers whose power is expensive. OTOH when solid state became practical, amp manufacturers realized the benefit of no output transformer and no filament circuit- so they could make an amp of the same power that cost 10% of the cost of a tube amp and sell it for 90% of the price of that tube amp. Speaker manufacturers saw this and realized that if they went to 4 ohms and less efficiency the lower cost to build the speaker meant they could make more money too. Solid state amplifier power is cheap, so this has worked great market-wise but its been one of the barriers between sounding like real music as opposed to a really good stereo.

Its always important to be careful about conflating personal anecdote with how things are: just because you have one efficient speaker that is bested by others of lessor efficiency does not mean that what I’m saying is incorrect.

@atmasphere I don't believe I was indicating your statements are incorrect. I actually said you made good points regarding distortion and speaker efficiency. My anecdote was strictly to illustrate my subjective preferences. In learning from one of the best engineers in the business who touted that greater benefits could be achieved from his amps if they were light loaded due to lowering distortion, making the amp work more efficiently, and extending tube life, that obviously aligns with your comments. From an engineering and design perspective, this is just the way it works, there is nothing otherworldly about it. That same engineer designed OTL amps. His preference would have been using them with 16 or even 32 ohm loads and he often lamented the lack of speakers being manufactured with those specs. As I told him and as I'll state now, unfortunately the audio world we live in isn't going to change course. We're not going to see a huge spike in the manufacturing of high impedance, high efficiency speakers anytime soon just because it's the better method.

@clio09 I wasn't really saying you were wrong, nor did I feel that you were saying that I was either, but I felt from your comments that I should flesh some things out a bit more. I agree with everything Roger states from your comment above. Despite conversations like this nothing is going to change; although people reading this might be a tad more careful.


Older solid state amps tend to run too little feedback which is why they can sound bright and harsh. Driving higher impedances helps with this simply by reducing distortion, which is the source of the brightness.

I think Roger didn't like that we run no feedback in our OTLs but the reason was I knew that if we used feedback, the phase margins of the amps would never permit enough to be applied. That's actually true of every tube amp. So to prevent the dreaded brightness coloration we ran no feedback at all and relied on other means to keep distortion at bay.

IMO to many people do not have a clear understanding of what bass actually is. Bass should be what the artist and producer have made it as part of the whole sound. Most artist have what I would call tight bass guitar that harmonizes with the drummer. This is where you need to separate bass into the multiple categories that it is. A kick drum I want to feel like a punch to the gut, a bass guitar I want to provide a solid tight rhythm to the track. What really confused most listeners was when Tool and others introduced drop D tuning. This lead listeners to think all songs should play down there, but they don’t. To many time people want to over produce “all” bass and you end up with mud or a lot of uncompressed vibrations. This is very common in hip hop as it masked over the crap sound of everything else that is all just over sampled tracks they borrow. Then you also run into the track production. If the artist and produce did not put the bass in you can’t make it appear out of thin air and expect it to sound good. Yes different speakers make bass in different ways but in the end you want to hear what the artist gave us. Everyone wants to be or thinks they are “producers” and can or could have done better. I think speakers and their numbers should best the main type of music you listen to. If a Marshall bottom is running 8 ohm and 90 db on most music I like I want my speaker to try and reproduce the sound the artist has made.

You're a legend in your own mind.