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OT - Help me understand Hi-Fi speakers

EPAIII

Diamond
Joined
Nov 23, 2003
Location
Beaumont, TX, USA
I did not mention speaker impedance before, but it is an important factor. And it is not just the lower, the louder.

What is important is that the impedance be properly MATCHED. The cable from the amplifier to the speaker(s) is what is known in electrical circles as a TRANSMISSION LINE. It is no coincidence that the amplifiers are rated in their power output. This has been so from the days before stereo, not to mention four, four, six, eight channel audio and their fractional channel bass. And there is a very basic principal that says that ANY electrical/electronic transmission line will transmit a maximum amount of power when the SOURCE and DESTINATION impedances are the same. That simply means that an amplifier with an eight Ohm output will transmit the most energy to an eight Ohm load (speaker). And, by the way, that maximum amount of energy is 50% of the energy being consumed by the amplifier's output stage. The other 50% becomes heat in that output stage and is the reason for the heat sinks usually found there.

Now ff a four Ohm speaker is connected to an eight Ohm amplifier output, then this transmission line is not properly terminated and there will be an impedance mismatch. Between Voltage and current, one will be greater than the optimal value, but the other one will be less and the product of the two which gives the amount of power in the speaker will be LOWER. So the full power of the amplifier will not be transmitted to the speaker. Worse yet, transmission lines are frequency sensitive so different amounts of power will be transmitted and converted to sound at different frequencies. That super flat amplifier response curve that the audio nuts just brag about will not appear at the air in front of the speaker and all that engineering effort and expense will be for naught.

If multiple speakers are connected to a single amplifier output, then the same principle applies but the overall effective impedance of the several speakers must be the value used. So two, eight Ohm speakers connected in parallel to one amplifier will act as a single four Ohm load and would be connected to a four Ohm amplifier output. Likewise for other parallel combinations. Series connections add so two eight Ohm speakers in series would be a 16 Ohm load and should be connected to a 16 Ohm output.

The problem of connecting multiple speakers to a single amplifier output, such as would occur in a PA system, is solved by using what is called a constant Voltage output with proper impedance matching transformers (and volume controls) at each individual speaker. That way large numbers of speakers can be connected to one amplifier while preserving good audio fidelity. These constant Voltage lines are NOT low impedance as this post would imply. In fact, they are HIGH impedance lines and only those individual transformers at the individual speakers bring the impedance down to the common speaker levels of 4, 8, or 16 Ohms.

Oh, and a 4 Ohm amplifier output impedance was NOT unheard of at that time. In fact many tube amplifiers, which had inherently high output impedances, often/usually had output transformers that supplied a choice of low impedance outputs, including 4 Ohms. Again, this goes back even before the days of stereo. Can you say "monaural audio"?

To a certain extent, modern, solid state audio amplifiers do employ feedback techniques at the output stage in order to deliver good quality audio regardless of the impedance of the speaker that is attached. This, again to an extent, makes the impedance matching of less concern. In effect the amplifier's output senses the load and effectively adjusts it's output impedance to match. But there are limits to this and if you want the best possible audio quality, then some attention to the combined speaker impedance is still called for.



So many questions, for you, I have.

That receiver is legit. I had one.
The power output is rated at rms, not peak, as all new garbage is.

I'd use the internal amp, fuck that yellow tooth shit.
As stated above (gustafson), you have to pay attention to impedance (ohms). It's resistance. (pm me if you'd like to understand this better, as with series or parallel wiring, you can cheat)
If I remember correctly, I didnt skim that spec link, it's rated for 8 ohm speakers, but is stable down to 4ish. That's basically unheard of, for it's time.

So without boring you with alot of bullshit, the lower the impedance, the more power is output, as long as the amp is stable at that impedance. That receiver gives you SOOOOO many options for speakers.

I've built more than a few car systems that have been in magazines, and some home systems that cost more than all my houses, and the dudes I've worked with have forgotten more than I'll ever know.
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
disclaimer: political comments inserted for the sole reason of inflaming those butthurt by political comments;)

NOW yer catchin' on. It's medical mental therapy "pro bono commune".

The public service to our brethren... of "pre-stretching" their tiny-tighty parts..... so the ruder-yet shocks to come don't kill the poor sufferin' bastid's OUTRIGHT!

:D
 

Yan Wo

Hot Rolled
Joined
Jan 22, 2014
Location
South Jordan, Utah, USA
[lots of good info trimmed]
... The audio purists will lecture you all day long about the advantages of their favorite speaker wire which is made with pure gold (or better) and costs millions of dollars an inch due to some highly proprietary process. But I have actually conducted BLIND tests with such wires against regular lamp cord as purchased at the local hardware and THEY can not reliably tell any difference. They then claim the test was not fair for some reason. But it wasn't. They just did not know which was which before hand so they were just guessing. ...

When I was more into this subject, I had fun asking the audio store salesman if speaker cable made a difference. They invariably said it did. I'd then ask, "Would it be better to spend $100 on speaker cable or $100 on better speakers?" The answer was always spend it on better speakers.

I was highly amused at the "unobtanium" cables that had directional arrows printed on them so you wouldn't hook them up backwards. :)
 

MCMLXIX

Aluminum
Joined
Dec 20, 2016
They are still making music in this century.
There are still a few breeders left that can carry a tune without injuring or killing any auto tunes.

Some current events for those who like the sound of cheese eatin surrender monkey.

Je suis malade Lara Fabian French and English subtitles - YouTube

For the pasta loving fascist cult members.

Lara Fabian Caruso digital clarity YouTube - YouTube

Something for 'Mericans living in the past.

Dream On - Postmodern Jukebox ft. Morgan James (Aerosmith Cover) - YouTube

Don't want to leave out those who claim the self appointed moral high ground.

Creep - Vintage Postmodern Jukebox Radiohead Cover ft. Haley Reinhart - YouTube

A little hope for the future generation amid this dark winter of discontent.

Angelina Jordan - Summertime / KORK - YouTube

The wings of destiny can be broken.
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
They are still making music in this century.
There are still a few breeders left that can carry a tune without injuring or killing any auto tunes.

Some current events for those who like the sound of cheese eatin surrender monkey.

Je suis malade Lara Fabian French and English subtitles - YouTube

For the pasta loving fascist cult members.

Lara Fabian Caruso digital clarity YouTube - YouTube

Something for 'Mericans living in the past.

Dream On - Postmodern Jukebox ft. Morgan James (Aerosmith Cover) - YouTube

Don't want to leave out those who claim the self appointed moral high ground.

Creep - Vintage Postmodern Jukebox Radiohead Cover ft. Haley Reinhart - YouTube

A little hope for the future generation amid this dark winter of discontent.

Angelina Jordan - Summertime / KORK - YouTube

The wings of destiny can be broken.

Lovely!

What can I say?

You have taste THAT discerning?

WTF are you still doing ... hostage.. in the Kaliphoneyah, SSR?

:D

As to "surrender monkey"? France had foolish leaders with 3-day delay HQ to field. That did not stop a valiant front line from bringing a serious measure of pee on "Schneller Heinz' Guderian's head - nor rear-guarding the extraction at Dunkirk the hard way.
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
Lamp cord is good. Watch the ribbed side for polarity when connecting. This does matter. You do not want one woofer going the opposite direction of the other.
For the shop I just went to Home Depot and bought 50 and 100 foot extension cords and cut the ends off as it was even lower cost for the long runs and no need to "hide" the wiring.
Never a believer in all this gold stuff or super heavy gauge in speaker wire as it seems to make no sense.
There is an argument to be made for gold plated RCA interconnect cables between stuff in a stack over very long use and life span and where it has to live.
Much good talk here from member EPAIII even if it a bit or a lot confusing. JST also one here with lots of chips in his shoes in sound systems.
Bob
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
Lamp cord is good. Watch the ribbed side for polarity when connecting. This does matter. You do not want one woofer going the opposite direction of the other.
For the shop I just went to Home Depot and bought 50 and 100 foot extension cords and cut the ends off as it was even lower cost for the long runs and no need to "hide" the wiring.
Bob

Works well. Lasts a long time.

My only "concession", "back in the day" was to buy a larger gauge, more long-lived jacket, and the "all-over tinned" flavour of zip cord!
 

CarbideBob

Diamond
Joined
Jan 14, 2007
Location
Flushing/Flint, Michigan
Works well. Lasts a long time.
My only "concession", "back in the day" was to buy a larger gauge, more long-lived jacket, and the "all-over tinned" flavour of zip cord!
Have a big stereo system rack at home not turned on for well over a decade plus with all this new stuff we have now.
Oh my, Where did I accept any less. This with BIC venturi six speakers. These good but not top end by any means.
Sound fill is one thing. Liking or loving it is another personal matter.
 

JST

Diamond
Joined
Jun 16, 2001
Location
St Louis
This is a huge example of "overthinking".

You have 170watts or so of output, which the amplifier can deliver. Get some speakers which you like the sound of, and which can take your 170 watts.

Check the speaker impedance, and be sure the amp can deliver full power into the speaker impedance.

Get some 16 or 18 ga zip cord for connecting the speakers, enough to reach from amp to speakers.. Try not to make that distance more than 25 feet or so. The longer you make it, the bigger the wire should be. System design DONE.

I did not mention speaker impedance before, but it is an important factor. And it is not just the lower, the louder.

What is important is that the impedance be properly MATCHED. The cable from the amplifier to the speaker(s) is what is known in electrical circles as a TRANSMISSION LINE. It is no coincidence that the amplifiers are rated in their power output. This has been so from the days before stereo, not to mention four, four, six, eight channel audio and their fractional channel bass. And there is a very basic principal that says that ANY electrical/electronic transmission line will transmit a maximum amount of power when the SOURCE and DESTINATION impedances are the same. That simply means that an amplifier with an eight Ohm output will transmit the most energy to an eight Ohm load (speaker). And, by the way, that maximum amount of energy is 50% of the energy being consumed by the amplifier's output stage. The other 50% becomes heat in that output stage and is the reason for the heat sinks usually found there. ........................

There is no speaker output in the world that is a transmission line, nor is it "matched". That's "techie-bunkum", pure and simple.


It's not a transmission line for the same reason that 1" of RG-58 is not a "transmission line"... Because the wavelengths used are much much longer than the line, and the characteristics of a transmission line do not develop.

As for the "matching"........which is not done.......

Have you ever heard of the term "damping factor" (DF) as applied to speakers?

That term is a measure of how much LOWER the amplifier output impedance is than the speaker impedance.

It is usual to have a DF of at least 20, meaning the amplifier output is 20x lower impedance than the speaker. A DF of 100 is not unknown.

By the way, while "matching" is sort-of done for open-back guitar speakers and amps, you would really hate how it sounds if the speakers were actually matched by the amplifier. Speakers are optimized for a low source impedance.

So much for matching...... and transmission line action.
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
This is a huge example of "overthinking".

You have 170watts or so of output, which the amplifier can deliver. Get some speakers which you like the sound of, and which can take your 170 watts.

Check the speaker impedance, and be sure the amp can deliver full power into the speaker impedance.

Get some 16 or 18 ga zip cord for connecting the speakers, enough to reach from amp to speakers.. Try not to make that distance more than 25 feet or so. The longer you make it, the bigger the wire should be. System design DONE.



There is no speaker output in the world that is a transmission line, nor is it "matched". That's "techie-bunkum", pure and simple.


It's not a transmission line for the same reason that 1" of RG-58 is not a "transmission line"... Because the wavelengths used are much much longer than the line, and the characteristics of a transmission line do not develop.

As for the "matching"........which is not done.......

Have you ever heard of the term "damping factor" (DF) as applied to speakers?

That term is a measure of how much LOWER the amplifier output impedance is than the speaker impedance.

It is usual to have a DF of at least 20, meaning the amplifier output is 20x lower impedance than the speaker. A DF of 100 is not unknown.

By the way, while "matching" is sort-of done for open-back guitar speakers and amps, you would really hate how it sounds if the speakers were actually matched by the amplifier. Speakers are optimized for a low source impedance.

So much for matching...... and transmission line action.

Gross MIS matching once ruled the day off ignorant scarce resources!

Son of a prominent RCA Engineer Alan S__ and I had co-founded our HS "Hi Fi Club", "stereo" still being a novel item.

When we hosted a HS dance?

One channel had a a 6L6 push-pull-parallel home-brew rig driving a borrowed James B Lansing US Navy surplus speaker once used to play cinema sound-tracks on carrier decks.

The OTHER channel had a DIY pair of KT-88's driving Alan's home brew speaker system executed in one-inch Marine plywood with about 60 pounds of common red bricks bedded in white "play sand" between the walls of the bass-reflex section.'

45 RPM record player had to be sat atop a six-inch slab of open-cell neoprene foam to NOT pick up feedback at the silly needle and bounce clear out of the groove!

"Primitive" it may have been, but "BFBI" primitive. A 2 Hz "wetted head" kettle-drum test record would blow out a match at four feet.

When he cranked up "409" at full-gallop and the front doors well over a hundred feet at the other end of the auditorium shook in time? We got threatened with arrest or expulsion...

.... and I knew we had a winner!

Had to rope-off four feet out from the edge of the stage, ten feet from the speakers.

Folk's chest cavities were resonating!

Sixty years ago this very year.

No fool like a young fool, whilst each in their turn still thinks THEIR generation is "the one" ... as will be "the first" ..... to invent immortality ...... and no one will ever again have to die!

409-the Beach Boys - YouTube
 

MCMLXIX

Aluminum
Joined
Dec 20, 2016
Lovely!

Thought you might like to update your play list.
Nothing better than a woman who can actually sing, without jumping around with their junk hanging out.

What can I say?

All of them currently active and interpreting the better of the past, while writing, arranging, producing and performing new material.

You have taste THAT discerning?

More eclectic and appreciative of the few who can stand up to a mic and emote an exceptional performance without a flashy distracting show.

WTF are you still doing ... hostage.. in the Kaliphoneyah, SSR?

Just an optimist hoping for sanity, common sense and self determination to come back into fashion. There is still a chance our "Leaders" will get out of the way and allow it to happen.

:D

As to "surrender monkey"? France had foolish leaders with 3-day delay HQ to field. That did not stop a valiant front line from bringing a serious measure of pee on "Schneller Heinz' Guderian's head - nor rear-guarding the extraction at Dunkirk the hard way.

I like the French and the Italians.
I only poke fun at those I like.
I thought I took a subtle jab at most all the sides with my selection.
The French under ground did a pretty good job of tossing wrenches into the German machine and never forget the Eiffel Tower still stands because the French special forces thwarted the precursor of 911 air liner attack against it.
 

GregSY

Diamond
Joined
Jan 1, 2005
Location
Houston
OK...here's my first speaker-specific question.


Looking at Cerwin Vegas....they now sell two lines, the SL and the (presumably) better XSL.

Why do the SL series have an 8 ohm rating and the XSL have a 6 ohm rating? Isn't 6 ohm kinda oddball?

Why do the SL series have 29hz low end and the XSL is higher at 43hz?CV12.jpgcvx12.jpg
 

tnmgcarbide

Diamond
Joined
Jul 6, 2004
Location
N. GA- 33.992N , -83.72W usa
don't confuse "hi-fi" and "sound" . they aren't the same , and shouldn't be confused.
in a shop environment, you probably want "Sound", which implies volume, clarity , dispersion ....PA type
stuff . it doesn't have to sound balanced and accurate as much as it needs to be listenable and un-distorted from most positions in the room ..

"hi-fi" could be a pair of 300B monoblocks pushing 5 WPC into a pair of Focal 6.5" fullrangers in TL

enclosures . solo cello, Django trio, mozart chamber music , beatles .. stunning...you can almost see the music.

great for the home listening room .... probably won't make it over that cnc lathe and 4" carbide shell mill. since you are entering the world of public address- go the music- store route .

you will get much more bang per buck with self powered pa speakers, and run the thing mono or stereo.
you probably won't notice in the din of tools.

good luck
 

thermite

Diamond
Joined
Sep 21, 2011
Location
Sol, Terra
don't confuse "hi-fi" and "sound" . they aren't the same , and shouldn't be confused.
in a shop environment, you probably want "Sound", which implies volume, clarity , dispersion ....PA type
stuff . it doesn't have to sound balanced and accurate as much as it needs to be listenable and un-distorted from most positions in the room ..

"hi-fi" could be a pair of 300B monoblocks pushing 5 WPC into a pair of Focal 6.5" fullrangers in TL

enclosures . solo cello, Django trio, mozart chamber music , beatles .. stunning...you can almost see the music.

great for the home listening room .... probably won't make it over that cnc lathe and 4" carbide shell mill. since you are entering the world of public address- go the music- store route .

you will get much more bang per buck with self powered pa speakers, and run the thing mono or stereo.
you probably won't notice in the din of tools.

good luck

"Mono" actually makes good sense. "Muzack" style.

For a shop, warehouse, even cubicle-ation-ated "office", the listener(s) ain't hardly EVER in a favourable position for anything more complicated to work as intended via ear, going through a sophisticated audio pre-processor nerve system - especially with any sort of industrial noise, or even rather mild obstructions such as pillars or columns.

Our HEARING senses are first and foremost a crucial warning system for survival, enhancing success when hunting food animals, avoiding becoming food when in turn being preyed upon. And not-only. Navigation in the dark. Etc.

Human has more than a few active signal processing tricks that surpress sounds under certain circumstances, enhance under others.. all to tilt the survival balance in favour of the human.

Complex system.

Scary capable.

"Music" is sort of an afterthought, though.

Like water-skiing behind a missile-armed destroyer?

:)
 
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