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

First,
  
Thanks to anyone who responds with whatever answers/opinions/advice comes from this. I'm retired, covid bound, Donna is taking care of everything holiday related, too much time, always curious.
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I happened across this in an old thread started by Ralph (atmasphere)

"Sixteen ohms, BTW is a very simple means for getting more resolution out of your system, as nearly every amplifier made sounds better on 16 ohms than it will on 4 or 8 ohms. Speaker cables become far less critical too."

My speakers are 16 ohms (Electrovoice horn tweeter, horn mid, 15" woofer, crossover, rheostats, from 1958).
Extremely efficient, I have more than enough power. Amp, now and in the past all had 16 ohm taps.
Of course I can hook them up to my Cayin's 8 ohm taps now and listen, but facts, opinions, advice, to learn is good.
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Lots of Questions? 

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

2. why speaker cables less critical? perhaps this is why I/we don't hear cable differences in my system?
I'm using my homemade twisted pair of cat 5 now (8 individually insulated small diameter solid core).

3.  to get exterior bias control: use 8 ohm tap for my 16 ohm speakers? (get alternate amp 4/8 no 16 tap,)

lose advantage(s)? 'sounds better'; 'more resolution'; 'speaker cables less critical'? 

this says slightly more mids:

http://blog.hughes-and-kettner.com/ohm-cooking-101-understanding-amps-speakers-and-impedance/

I can fine tune my speakers via their two rheostats: 'presence' and 'brilliance', so not really an issue for me.

4. Importance of Bias Control

how important is Bias? (I don't care about heat, power output, or tube life, just as bias affects sound). Frankly, using vintage tube receiver Fisher 500C, 800C and Fisher Mono Blocks 80Z, I have never checked or adjusted bias. I just put the control in the center position when cleaning insides/controls.

I have always used 16 ohm taps of various vintage tube and SS amps and newer current tube Cayin A88T. (original version, the only one with 16 ohm taps). It's bias control is internal, versions with safer external bias do not have 16 ohm taps.

5. replace their two rheostats? ('presence' and 'brilliance': copper wire-wound on ceramic body, mid/neutral position).
I have them in neutral position now, l/r frequency response equal.   

do I need to keep rheostats 16 ohms? use 8 ohm rheostat with 16 ohm drivers?

sales sheet says 16 ohm, but data sheet shows range 1.0 to 5k ohms. 

https://www.mouser.com/datasheet/2/303/controls_rheostats-1228697.pdf

does that mean, the drivers will draw whatever they draw (varies thru frequency range anyway), doesn't matter as long as rheostat range starts 1.0 ohm, extends past say 100.0 ohms?

https://www.mouser.com/datasheet/2/303/controls_rheostats-1228697.pdf

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thanks, Elliott











elliottbnewcombjr
atmasphere's avatar
atmasphere
11,756 posts
 
I messed about with them for quite a while. It is again clear to me that these speakers were designed with the control of mid to woofer and tweeter to mid in mind.
@eliottnewcombjr A little trick you can do is mark the correct position with a bit of tape. Then about once a month or so work the Lpads back and forth to clear corrosion, and reset them to the original level you marked.


BTW I'd be careful about using an analog mulitmeter when setting the bias on a newer amplifier (a vintage amp's bias procedure might expect that you are using a multimeter). A multimeter has a lower resistance than a DVM or VTVM (Vacuum Tube Volt Meter) and that can affect your reading a bit, how much depends on how high the voltage is (the higher the voltage, the more accurate they become) and the impedance of the circuit. Multimeters a nice to look at in a post-industrial world so to speak, but DVMs are actually easier to use and more accurate unless you get a junky one. If you want to use vintage stuff to do this task, get a VTVM and have it serviced out and calibrated.

lewm
12,858 posts
 
Ralph, I am not sure what you are saying, because the terms "multimeter" and "DVM" are so often conflated with one another.  VTVM is a clear acronym, because you are talking about a vacuum tube voltmeter.  But let's take my Fluke 87 meter.  It is a "multimeter" in the sense it can read DC and AC voltage, capacitance, DC and AC current, and it includes a diode checker.  But it is also a DVM in the sense it is digital and solid state.  On voltage settings, it offers 20Megohm resistance across the leads.  So, what is a "multimeter" and how do you distinguish it from a DVM?  Or, why isn't my Fluke a multimeter?  Folks like Elliot might benefit from this clarification even more than I. For sure, any respectable voltmeter can measure the -10V to -50V range of the grid bias voltage that is typically seen for most tube amplifier output tubes.
elliottbnewcombjr OP
5,304 posts
 
I made a nice long wooden screwdriver, but Steve's doing it the first time, it's an excuse to meet him.

I will bring my toy multimeter for him to throw in the trash or teach me how to use it for bias.
speakermaster
738 posts
 
A 16 ohm speaker was designed for high efficiency and damping when the amps did not have high damping factors because of high output impedance so they made the speakers that way to control the sound themselves and not rely on an amp to do it for them. the main benefit of that is that the speakers respond very quickly to the input from an amplifier in the micro dynamic sense because of this, they have a tendency to make the music come to life and breathe the air in the room turning your room into the studio where the recording was made. the key is to find the best recordings to play on them and when you do you will know it because the sensitivity of the mic that was used will match the sensitivity on playback and you will hear what you have been missing.
atmasphere's avatar
atmasphere
11,756 posts
 
Ralph, I am not sure what you are saying, because the terms "multimeter" and "DVM" are so often conflated with one another. VTVM is a clear acronym, because you are talking about a vacuum tube voltmeter. But let's take my Fluke 87 meter.
If it has a digital display its a DVM and should have a similarly high impedance like a VTVM does. A multimeter is an older analog device with an analog meter. Its impedance is much lower and so its voltage measurements in sensitive circuits will be lower than actual (Ohm's Law after all...). I agree that 'multimeter' and 'DVM' are often conflated.
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