16 ohm speakers: any amp sounds better with more resolution. speaker cables less critical.

+1 @atmasphere and
@lewm
Impedance matters on the load presented to the Amp, as Lew said there is no free lunch, the autorformers yes work if you have the problem but it is best to avoid it.As @charles1dad explained and he is very fond of low power SETs you can benefit ALOT from the 16 ohm Impedance.

Chuck's post as much as I respect and sympathize with his opinions it could be misleading, it depends on which specific experience he might have, IIRC he has Pass amps?
My own experience with several tube amps (especially SET) you would want if possible 16 ohms. Atmasphere amps are a special case have MA-1s myself and they can work with 8 / 6 ohms but 12 and 16 ohm are definitely better

Just my 2c

@elliotb  

That video also ignores feedback, distortion, current requirements. easy to be misinterpreted.

That was the whole point of the video was to be misinterpreted in order to bias the viewer into preferring a 4 ohm speaker design - always, because it will be louder (all things equal, which of course they are not). Eric does make the completely worthless disclaimer at the beginning of the video that his viewpoint is only through the perspective of a speaker builder and doesn't consider the amplifier whatsoever.  Why is this worthless?  Because there is always an amplifier and speakers respond to amplifiers differently depending on the amp design.

Can you even imagine a video where an Andrew Jones or Nelson Pass plays photon torpedo noises through 4 ohm and 8 ohm speakers while claiming the one producing the loudest noise is the best - always - categorically....and even to go as far as claim the 8 ohm is obsolete?  It's laughable and goes to show the market Eric is largely targeting. This doesn't mean his speakers don't sound decent - it just means his marketing methods can be off-putting because he assumes people are stupid - at least in a video like this.   

atmasphere

thanks for your clarity of these issues. I'm sticking with 16 ohm tap.

remaining questions:

1. how importance is bias to sound? (I don't care about heat or tube life).

......................

2. speaker cable inductance ..... gauge ____ awg

mijostyn said

" the wire you are using probably has high inductance. You should use 18 gauge wire that is a jacketed twisted pair like this".

Guage: Cat 5 8 strands is 15 awg. Two Cat 5's, 16 strands, is 12 awg.

https://www.wirebarn.com/Combined-Wire-Gauge-Calculator_ep_42.html

I don't really understand inductance. If speakers are high efficiency (mine are), and I/you have more than enough power from the amp, speaker

3. equiv 15 awg, is inductance an issue?

Inductance (Back EMF) might increase amount of current needed, but

4. enough power: does it have any effect on the music's frequencies? 

..............................

atmasphere

Voltage/Current

I read and re-read your paper you linked,

http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html

quite interesting. The Tekton video about using 4 ohm in lieu 8 ohms, 'getting more volume from 4 ohm' plays directly into your distinction between sensitivity and efficiency, which I never understood clearly before, thanks for that. That video also ignores feedback, distortion, current requirements. easy to be misinterpreted.
................................

Level Controls

Electro-voice AT37 Attenuator's spec says 16 ohm; AT38 spec says 8 ohm.

https://products.electrovoice.com/binary/AT37%20and%20AT38%20EDS.pdf

EV instructions say start at 0 and cut from there. Zero as start, and positive numbers indicating more or even more attenuation (not boost)

My level controls were evidently custom via Fisher: innards: exposed copper wound ceramic; exterior bronze finish recessed cup/handle for flush mount. A centered position, then boost or cut from that.

The level controls are after the electro-voice 16 ohm crossover X336. Electro-voice crossovers were contained in a can filled with tar (smaller x36 shown), mine are 62 years old.

https://products.electrovoice.com/binary/X6_X8_X425_X825_X36_X336_X2635_Engineering_Data_Sheet.pdf

this shows X336 crossover and electro-voice attenuators AT37 used in various Electro-voice 3 way Speakers.

https://www.ebay.com/itm/VINTAGE-EV-CROSSOVER-X336-2-PONTETIOMETR-CENTURION-VERY-CLEAN/274619211421?...

.......................................

Components (anybody still awake?)

All my speaker's components came from my uncle's Fisher 'President II Console I inherited, using electro-voice drivers and crossover. I have all the components, burned the wood in my fireplace.

https://www.radiomuseum.org/r/fisher_president_ii_console_3000m.html

Electro-voice speakers used their 15WK; Fisher chose the 15W

https://www.ebay.com/i/114584280677?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&am...

https://products.electrovoice.com/binary/15W,%2015BW,%2015WK,%2015BWK%20EDS.pdf

Monster magnet, they weigh 37 lbs each. I've re-coned the woofers twice, I just checked, paper/cloth cone/coil kits still available. I have a spare 15W downstairs also.

I replaced the original T35 horn with T350 which is +3db efficiency, useful as we age, nice to have the level control.

http://www.cieri.net/Documenti/Istruzioni/Electrovoice%20-%20Tweeter%20T35,%20T35B,%20T350.pdf

spare pair downstairs.

the midrange is this crazy compound diffraction horn

https://products.electrovoice.com/binary/847A%20EDS.pdf

it looks like hell, but sounds terrific.

spare downstairs

...............................

These Level Controls give a lot of flexibility, BUT, it takes a lot of work getting both sides properly matched, the various sound positioning options of the McIntosh Mode Switch is the key my success. As frequencies change, i.e. you don't want certain piano notes left, others centered, others right. Imagine a singer's voice wandering. it's a big sigh of relief when you finally get it.

The Zero (Speltz) Autoformers are not a free lunch. As with any transformer, they trade off current and voltage. So if you mate an amplifier with a high-ish output Z to a speaker with a low input Z, via the Zero, you lose voltage in direct proportion to the gain in impedance seen by the amplifier. This affects apparent amplifier power. It does work, but it’s not a perfect world. I happily used the Zeros for many years as an interface between my Atma-sphere amplifiers (OTL amplifiers with a high output Z) and my Sound Lab M1 speakers, which had a midrange impedance dip down to 2 ohms and was under 5 ohms impedance across a considerable portion of the midrange. The Zeros made it possible to drive them. Then I traded my M1s for a pair of Sound Lab 845PX speakers. The match was just barely acceptable, because the 845s + Zeros were sucking more amplifier power than the M1s, but with the intellectual input of a guy in Australia and by changing one of the two audio step-up transformers in the SLs and ripping out the crossover components, I was able to completely eliminate the impedance dip typical of SL ESLs. (Ralph knows this story very well.) In fact, my 845PXs now present an impedance that is never lower than 20 ohms from around 200Hz to 5kHz, and they are also much more efficient, for technical reasons too arcane to go into here. The load presented by the Sound Labs is just heaven for my Atma OTLs, and I don’t need autoformers. So, use ’em if you need ’em, but it’s still best to select either a speaker suitable for your amp or vice-versa, in terms of impedance.
To the OP. I advise you to set those controls the way you like them, then measure R across each rheostat, then substitute discrete resistors of that value, one for each rheostat (if I am correct that each speaker has 2). This will get you a big upgrade in clarity. When you do that, select very high quality resistors of very high wattage rating; that also pays off.

I usually wire mids and highs at 8-16 ohms. I use small planars, or ribbons, both like the higher impedance on valve amps especially.

SS a little different, Pass design puts a smile on my face at just about any impedance.. Not often I wire with a single driver, bass, mids or highs.. Subs, I still wire at 8 -12 ohms. Just less distortion..

Regards

i wonder why there is no move to democratize 4-ohm equipment, why it continues to be very expensive and exclusive.

very cool product @tvad   I was unaware of it and it would fun to experiment with. I will say, it's nice that my amplifier has 4, 8, and 16 ohm taps and I have spent a lot of time testing various taps along with differing NFB settings.

But why would anyone need this when Einstein above tells us that 4 ohm speakers are always best in every application?  The YouTube video of some guy (possibly a wizard?) proving that a louder a noise can be made by presenting a 4 ohm load to an amp compared to an 8 ohm load was like magic.  That guy is a genius - he figured out that halving the load impedance will double the power output of an amplifier and make louder noises.    

Hello Elliot,
I don’t believe that you’ve missed anything. The Eric Alexander video wasn’t particularly compelling but was more about volume differences.
Ralph’s explanation to you regarding the advantages of high impedance speaker load was more thorough, reasonable/logical and I feel better supported by listening experiences. Less distortion as well as diminished demands on the driving amplifier (Power/current) seem like unquestionable positive factors.

Ralph concludes that the sound quality becomes more relaxed and with increased detail rather than etched or lean, he is right.
Charles

I the irony of MC complaining about being insulted isn't lost on me. lol

Holy crap! Coulda sworn you were on the list but not yet. Oh well, give it time. Anyways, not being on the list yet allows me to say: That's an insult not an argument. Which is more response than it deserves.

one time at bandcamp our speaker designer became an amplifier expert...not !

my $ is on Ralph

of course, it’s an unfair advantage when the amplifier is designed for the load and the load is designed to be relatively easy....by the same mindful designer.... Vandersteen M7 or M5, there are of course other designers doing both, MBL, ATC, etc...

i believe there is an exception, keeping the amp in class A by light loading..ala Roger Modjeski

And yet, the guy who designs some of the most fantastically successful speakers made anywhere in the world today says nevermind 16 ohms, even 8 ohms is obsolete.

Nearly all legendary TANNOY speakers are 8 Ohm

Zu Audio speakers are 16 Ohm and they are very popular TODAY 

Those 8-16 Ohm speakers are HIGH EFFICIENT SPEAKERS

Who’s the guy in your video ? It’s nonsense

Did MC miss the part where the OP has 16 ohm speakers driven by a Cayin tube amp? Of course the sound quality is likely to be best when you are matching the impedance of the speaker to the value of the output transformer tap. The higher ohm tap results in less distortion, increased bandwidth and better efficiency. Apparently MC loves distortion and small bandwidth trying to drive 16 ohm speakers from a 4 ohm tap. Oh and there will likely no bass left at all in the speaker output let alone impact and texture. This actually explains a lot of his advice.

And yes, looking at Eric's video and the premium he places on volume I understand why he leans towards 4 ohm designs.   Lower impedance designs are simply an approach to get more power out of solid state designs....not getting lower distortion. sheesh....

Am I missing something?

In the video he didn't mention sound QUALITY at all. Nor any comment on AMP performance/distortion differences.

His comments are about the SPEAKER, not the amp. He emphasizes, it's his choice for his high performance, high efficiency SPEAKERS . His demo is about loudness, saying 4 ohm will produce 3db more VOLUME than 8 ohm. IOW, it helps him with efficiency.

the guy who designs some of the most fantastically successful speakers made anywhere in the world

Really?

B

Nevermind Tekton speakers. It is getting nauseating that an answer to everything starts with "Eric". Pushing too much sometimes pushes away.

And yet, the guy who designs some of the most fantastically successful speakers made anywhere in the world today says nevermind 16 ohms, even 8 ohms is obsolete. https://www.youtube.com/watch?v=tMAO9LPsups

My amp has 4, 8, and 16 taps. If my speakers are 4, what strain, if any, on any of my amp tubes will that have? 

They don't. It does change the sound and in making it more lean and etchy it can seem to be more detailed. Its not.

This isn't how it works.

What's going on is how the amp interfaces with the speaker, how the amp behaves when its driving a higher impedance.


And how the amp behaves is that it will make less distortion, and this will be heard as 'more relaxed more detail'; IOW neither 'lean' or 'etchy'; quite the opposite.


A tube amp will make less distortion (assuming that it has a 16 ohm tap if using an output transformer) and so will have less of the lower ordered harmonics. In this way it will simply sound more neutral. Because there is less distortion, there will be less to mask detail.


A solid state amp tends to not have much of the lower ordered harmonics- their distortion signature tends to be more of the higher ordered variety. But again, they will make less of it, so they will sound sound smoother (since these harmonics are interpreted by the ear has brightness and harshness) and more detailed; the latter simply because there will be less distortion to mask detail.


So we see that in both cases we have the same benefit. Now if its between 4 ohms and 8 ohms, the 8 ohm solution will have lower distortion than the 4 ohm. Again, less distortion (though not as low as with 16 ohms). This BTW is easily seen in the specs of any amplifier. Being that we really are talking about high end audio, where the goal should be to get the music to sound as real as possible, lowering the distortion should be part of that solution :)

As far as the speaker cables go, its a simple fact that at 4 ohms, the DC resistance of the cable can play a role in the damping available to the speaker. The same speaker cable on a 16 ohm speaker is simply going to have a negligible effect on damping.


Now this depends largely on the assumption that the higher impedance speaker is simply higher impedance, and otherwise has the same breakups and other anomalies that it would have if 4 ohms or 8.


If your speaker has level controls or level adjustments, they are there for one reason only- the voltage response of the amplifier is unknown, and the control is there to allow the speaker to be adjusted to that voltage response. This is indicative of the speaker being built for amps that behave as power sources rather than voltage sources (for example, any tube amp that runs zero feedback). For more on this topic see:
http://www.atma-sphere.com/en/resources-paradigms-in-amplifier-design.html

My speakers are 16 Ohm (Zu Audio Druid).

There is a simple trick recommended by Nelson Pass (First Watt):

Put 160 Ohm (5w) resistor across the cable terminals on the speaker.
Some reviewers love it with 16 Ohm speakers.

Hi Elliot,
The "rheostat" has nothing to do with the impedance of the speaker. It is just a potentiometer that varies the amount of power going to either the tweeter or midrange horns.
16 Ohm speakers are more efficient. Not much current is required to drive them so heavy gauge speaker wire is not necessary. But, the wire you are using probably has high inductance. You should use 18 gauge wire that is a jacketed twisted pair like this, https://www.parts-express.com/belden-6300ue-18-awg-2c-cable-plenum-rated-in-wall-speaker-wire-100-ft...
Always use the 16 ohm tap. If you do not have one the 8 ohm tap will do. 

1. why/how do 16 ohm speakers make amps sound better, with more resolution?

They don't. It does change the sound and in making it more lean and etchy it can seem to be more detailed. Its not. 

Because of the way they are wired its very easy for Eric Alexander to make his Tekton Moabs in either 8 ohm or 4 ohm. Everyone following the advice you mentioned told me to order 8 ohms. It will be so much better. Especially since I have a tube amp. They made all the same technical arguments you have undoubtedly heard. I talked with Eric and went with 4 ohms. Hard to imagine how these speakers could be any better.  

But if you want stories, here is the antidote to the 16 ohm story: 
https://www.youtube.com/watch?v=tMAO9LPsups  

2. why speaker cables less critical? perhaps this is why I/we don't hear cable differences in my system?  

We have no idea why you don't hear differences in your system. Could be the wires you are comparing are so similar the differences are so small its too hard to hear. The differences are there, guaranteed. My first experiment was with ordinary 14 gauge lamp cord, two runs shotgun vs one. Not much difference but it was there. Everything from that point on has been orders of magnitude greater and easier to hear. So its there, just waiting on you to find it. 

I'm using my homemade twisted pair of cat 5 now (8 individually insulated small diameter solid core).

The good news is this is so far down the scale you have nowhere to go but up.
Forget impedance. Forget construction. Focus on sound quality.