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

mijostyn

thanks for your comments.

turns out eight 24 gauge is equiv to 15 gauge. any other factors of cat 5 involved with 'inductance' concerns?
chakster

thanks. as usual, I wish you lived next door so I could hear your variety of speakers, equipment, ....

160 ohm resistor across the terminals. any idea what/why?
three_easy_payments

thanks, we agree about the video and advantages of 16 ohm reduced distortion.

In the beginning, when 4 ohm speakers showed up, some sounded very good, however they were small enclosures, and it seemed to me they needed a heck of a lot of power, the complete opposite of my goals. I didn't know about amount of distortion involved.

I encourage trying tube amps, and the way to save money/size/heat/cost of tube rolling/replacing, is to start with efficient speakers, thus you can stay in the 35/30/25 wpc world of tubes, even less if you use horn speakers or other highly efficient speakers. My friends system uses 8 wpc tube amps.

I remodeled my office recently, my friend has an unused pair of KEF's, I remember them sounding great, I was going to use my Carver Cube 200wpc, enough power for them. However they are 15" deep (to get more box volume, avoiding port(s) I suppose), sadly too deep for bookshelf use.

charles1dad

Thanks for your reinforcement of Ralph and other's comments.

I knew the speakers were very high efficiency (horns), and needed little power (16 ohms is easier, I knew that), but I was unaware of the inherent advantages to the amp regarding lower distortion.
Roger Modjeski always recommended "light loading" his amps and gave numerous reasons why this was beneficial. Some were mentioned by @atmasphere in a previous post. On a pair of 8 ohm speakers I run my RM10 off the 4 ohm tap. The difference is very noticeable versus the 8 ohm tap. Roger often opined why 16 ohms speakers went out of style. Oddly enough in cleaning things up around Roger's shop I ran across a set of Chartwell speakers that are 15 ohms. Going to give them a try on my RM10.