[[email protected]]

My receiver(as well as most built in the last 20 years) calls for 8-16ohm loads.

[Trevor]

On 29/11/2014 12:35 AM, wrote:
My receiver(as well as most built in the last 20 years) calls for 8-16ohm loads.


And many decent amps built in the last 20 years can handle 2-4 ohm
loads. But the rated impedance of speakers is only a VERY rough guide
anyway.

Trevor.

[geoff]

On 29/11/2014 2:35 a.m., wrote:
My receiver(as well as most built in the last 20 years) calls for 8-16ohm loads.


"6" ? I guess they couldn't decide on 4 or 8, so split the difference.

Many amps of this era work down to 4 ohms. 16 ohms is pretty much only
valve (tube) and antique solid-state amps, though of course 16 will in
fact work with any output lower.



geoff

[[email protected]]

geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!

[Trevor]

On 2/12/2014 12:19 AM, wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!


Many cheap receivers with limited current capability specify 8 ohms or
more, regardless of age. Conversely many good amps can handle loads as
low as 2 ohms without a problem.

Trevor.

[Mark Zacharias]

"Trevor" wrote in message
...
On 2/12/2014 12:19 AM, wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie
then!


Many cheap receivers with limited current capability specify 8 ohms or
more, regardless of age. Conversely many good amps can handle loads as low
as 2 ohms without a problem.

Trevor.




Speaker impedances have not really changed - they are rating them a bit more
accurately these days.

Mark Z.

[[email protected]]

Thanks Trevor! Everyone who visits my place think I have a nice sounding system, cheapo receiver aside. smh...

http://www.hifiengine.com/files/imag....prev iew.jpg

[Trevor]

On 3/12/2014 10:28 AM, wrote:
Thanks Trevor! Everyone who visits my place think I have a nice sounding system, cheapo receiver aside. smh...

http://www.hifiengine.com/files/imag....prev iew.jpg


As always, as long as it can drive your speakers, the speakers and room
(and quality of source material) determine the sound quality, NOT your
receiver! And your friends probably have no idea what good sound is
anyway. Most don't.

Trevor.

[Trevor]

On 3/12/2014 12:21 AM, Mark Zacharias wrote:
"Trevor" wrote in message
...
On 2/12/2014 12:19 AM, wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an
oldie then!


Many cheap receivers with limited current capability specify 8 ohms or
more, regardless of age. Conversely many good amps can handle loads as
low as 2 ohms without a problem.



Speaker impedances have not really changed - they are rating them a bit
more accurately these days.

Mark Z.


Partly true to the second part, mostly no to the first part. Some
manufacturers use the impedance minimum fairly closely these days.
Others are just an estimate of what they think the amp rating should be.
But speaker impedances HAVE generally dropped over the last 50 years or
so. First with the change from valve amps they generally went from
~16ohm to 8ohm. Then with the improvement in current handling of
transistor amps (and the increase in multiple small bass drivers vs one
larger driver), many have dropped from ~8ohm to ~6 or 4 ohm.
In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but the voice coil *resistance* of
many drivers has decreased. That affects the system impedance, and is
easy to measure. And some manufacturers still produce their drivers with
voice coil resistance options, or even custom make them if you buy enough.

Trevor.

[[email protected]]

Trevor wrote:

"On 3/12/2014 10:28 AM, wrote:
Thanks Trevor! Everyone who visits my place think I have a nice sounding system, cheapo receiver aside. smh...

http://www.hifiengine.com/files/imag....prev iew.jpg


As always, as long as it can drive your speakers, the speakers and room
(and quality of source material) determine the sound quality, NOT your
receiver! And your friends probably have no idea what good sound is
anyway. Most don't.

Trevor. "

Well, perhaps we could arrange for you to come and listen to my cheap, crappy receiver & speakers and decide for yourself, thank you very much.

[[email protected]]

Trevor wrote: "In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but"

So given that, the question should be, are mfgs listing the avg, max, or min impedance on the cabinet spec sticker?

[chuck]

On Thu, 4 Dec 2014 05:10:48 -0800 (PST), wrote:

Trevor wrote: "In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but"

So given that, the question should be, are mfgs listing the avg, max, or min impedance on the cabinet spec sticker?


Since there is no standard, the manufacturers can list whatever
impedance they want; within the range of impedances that the speaker
has in its frequency range. For example, some speakers rated at 4
ohms dip below 2 ohms at certain frequencies.

[[email protected]]

chuck:

That's the problem: No standards. I was told about some standard for audio(measurement) that was abandoned in the '70s or thereabouts. Forgot the name of it.

[geoff]

On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

geoff

[geoff]

On 5/12/2014 4:40 a.m., chuck wrote:
On Thu, 4 Dec 2014 05:10:48 -0800 (PST), wrote:

Trevor wrote: "In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but"

So given that, the question should be, are mfgs listing the avg, max, or min impedance on the cabinet spec sticker?


Since there is no standard, the manufacturers can list whatever
impedance they want; within the range of impedances that the speaker
has in its frequency range. For example, some speakers rated at 4
ohms dip below 2 ohms at certain frequencies.



Some do specify a 'minimum impedance', and some even at what frequency
that occurs. And the minimum *is* the most relevant.


geoff

[[email protected]]

geoff wrote: "On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

geoff"

My dB Plus 880s are speced 8ohms. Not all that outlandish.

[Trevor]

On 5/12/2014 12:10 AM, wrote:
Trevor wrote: "In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but"

So given that, the question should be, are mfgs listing the avg, max, or min impedance
on the cabinet spec sticker?

The simple answer to that is no (unless by chance), no, and some.

Trevor.

[Trevor]

On 5/12/2014 2:42 AM, wrote:
chuck:

That's the problem: No standards.
I was told about some standard for audio(measurement) that was
abandoned in the '70s or thereabouts.
Forgot the name of it.


The great thing about standards is there are so many to choose from! :-)

Trevor.

[Trevor]

On 5/12/2014 12:08 AM, wrote:
Trevor wrote:
"On 3/12/2014 10:28 AM, wrote:
Thanks Trevor! Everyone who visits my place think I have a nice sounding system, cheapo receiver aside. smh...

http://www.hifiengine.com/files/imag....prev iew.jpg


As always, as long as it can drive your speakers, the speakers and room
(and quality of source material) determine the sound quality, NOT your
receiver! And your friends probably have no idea what good sound is
anyway. Most don't.

Well, perhaps we could arrange for you to come and listen to my cheap, crappy receiver & speakers and decide for yourself, thank you very much.

I seriously doubt that's gonna happen, but the real question is "why do
you care what others think anyway"? As long as YOU are happy!

Trevor.

[Trevor]

On 5/12/2014 10:00 AM, wrote:
geoff wrote: "On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

You can still buy "16ohm" drivers. But yes, very few domestic HiFi
speaker *systems* are specced at 16ohm these days.


My dB Plus 880s are speced 8ohms.


So just like the majority of speakers made in the last 40-50 years then.

Trevor.

[geoff]

On 5/12/2014 12:00 p.m., wrote:
geoff wrote: "On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

geoff"

My dB Plus 880s are speced 8ohms. Not all that outlandish.



Read again .

geoff

[[email protected]]

On Friday, December 5, 2014 11:10:29 PM UTC-5, geoff wrote:
On 5/12/2014 12:00 p.m., .com wrote:
geoff wrote: "On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

geoff"

My dB Plus 880s are speced 8ohms. Not all that outlandish.



Read again .

geoff


Read what again, geoff? I'm not psychic.

[Mark Zacharias]

"Trevor" wrote in message
...
On 3/12/2014 12:21 AM, Mark Zacharias wrote:
"Trevor" wrote in message
...
On 2/12/2014 12:19 AM, wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an
oldie then!


Many cheap receivers with limited current capability specify 8 ohms or
more, regardless of age. Conversely many good amps can handle loads as
low as 2 ohms without a problem.



Speaker impedances have not really changed - they are rating them a bit
more accurately these days.

Mark Z.


Partly true to the second part, mostly no to the first part. Some
manufacturers use the impedance minimum fairly closely these days. Others
are just an estimate of what they think the amp rating should be. But
speaker impedances HAVE generally dropped over the last 50 years or so.
First with the change from valve amps they generally went from ~16ohm to
8ohm. Then with the improvement in current handling of transistor amps
(and the increase in multiple small bass drivers vs one larger driver),
many have dropped from ~8ohm to ~6 or 4 ohm.
In any case ALL speakers vary wildly in *impedance* across the frequency
range, especially ported speakers, but the voice coil *resistance* of many
drivers has decreased. That affects the system impedance, and is easy to
measure. And some manufacturers still produce their drivers with voice
coil resistance options, or even custom make them if you buy enough.

Trevor.




What I meant to suggest is that so-called "8-ohm" speakers have always
actually been closer to 5 or 6 ohms. Should have been clearer.

mz

[Peter Larsen[_3_]]

"Mark Zacharias" skrev i en meddelelse
...

What I meant to suggest is that so-called "8-ohm" speakers have always
actually been closer to 5 or 6 ohms. Should have been clearer.

And this is because the loudspeaker impedance spec still just tries to tell
you what tap on an output transformer it is suggested that you should use.

It does however appears to be so that some manufacturers "slide" some of
their "8 ohm" designs down in load impedance to get them just a wee bit
louder in practical use because it allows them to use less magnet or because
more magnet does not fit the chassis well, as could be the case with the
Coral 8F60.

Unfortunately it didn't have the powerhandling to match the increased power
drawn from the amplifier and/or was optimistically spec'ed by Coral, be
warned ye that gather Coral stuff, divide its powerhandling spec by 2 or 3,
there are no more repkits, even if the 2420 kit will fit a M100 physically.

I don't really know whether they also get away with using less copper, that
would be a win win. But I wonder, I remember Dick Pierce explaining how
design parameters fit in a way that suggests that a nominal 8 Ohm design is
the most cost & power efficient.

On a more serious note: transistor amplifiers should be able to drive half
the nominal loudspeaker load because that is how the real world loudspeaker
load is likely to look anyway once phase between voltage and current is
allowed for. Note that this phase angle issue between voltage and current
means that the zero crossing in AC is an unplesant place to be for an
amplifier with current being ordered from the loudspeaker and no output
voltage available.

mz

Kind regards

Peter Larsen

[geoff]

On 7/12/2014 2:44 a.m., wrote:
On Friday, December 5, 2014 11:10:29 PM UTC-5, geoff wrote:
On 5/12/2014 12:00 p.m., .com wrote:
geoff wrote: "On 2/12/2014 2:19 a.m., wrote:
geoff: My 1995 JVC receiver specifies 8-16ohms. Guess that's an oldie then!



Certainly pandering to people from a different era. Probably said that
to avoid tech-support calls from the elderly. Doubt there have been any
(domestic hifi) speakers sold since mid-70s that spec at 16 ohms !

geoff"

My dB Plus 880s are speced 8ohms. Not all that outlandish.



Read again .

geoff


Read what again, geoff? I'm not psychic.



Or good at readingf comprehension, it seems!

"16 ohms". SIXTEEN !

Seen any in the last 40 years ?

geoff

[geoff]

On 7/12/2014 1:01 p.m., Mark Zacharias wrote:

Trevor.




What I meant to suggest is that so-called "8-ohm" speakers have always
actually been closer to 5 or 6 ohms. Should have been clearer.

mz

That is equally false. An 8 ohm driver will often have a DC RESISTANCE
often around 6 ohms, but it's impedance will likely be very different,
and change with frequency.

Then throw in a crossover network and you'll have even wider variation.


geoff

[[email protected]]

geoff wrote: "- show quoted text -
Or good at readingf comprehension, it seems!

"16 ohms". SIXTEEN !

Seen any in the last 40 years ?

geoff "

I am not always reading this from a desktop. All I did was state the range of acceptable speaker impedance(8-16) listed on the back of my receiver.

Who has this "reading comprehension" problem you repeatedly point to?

[Peter Larsen[_3_]]

"geoff" skrev i en meddelelse
...

"16 ohms". SIXTEEN !

Seen any in the last 40 years ?

Lowther comes instantly to mind and back in my roadie time in the 1970'ties
we spec'ed all loudspeaker units at 16 Ohms for optimum amplifier usage and
to minimize cable loss.

geoff

Kind regards

Peter Larsen

[geoff]

On 7/12/2014 11:14 p.m., wrote:
geoff wrote: "- show quoted text -
Or good at readingf comprehension, it seems!

"16 ohms". SIXTEEN !

Seen any in the last 40 years ?

geoff "

I am not always reading this from a desktop. All I did was state the range of acceptable speaker impedance(8-16) listed on the back of my receiver.

Who has this "reading comprehension" problem you repeatedly point to?



8 would seem to be the new sixteen ?

geoff

[[email protected]]

geoff wrote: "2:54 PMgeoff
- show quoted text -
8 would seem to be the new sixteen ?

geoff "


In ENGLISH please.

[geoff]

On 8/12/2014 9:11 a.m., wrote:
geoff wrote: "2:54 PMgeoff
- show quoted text -
8 would seem to be the new sixteen ?

geoff "


In ENGLISH please.



In reply to my comment about the extreme rarity of (specifically) 16 ohm
speakers since the mid-'70s (probably earlier) , your comment seemed to
imply that I thought your 8 ohm speakers were some sort of rarity.

Whereas since solid-state days 8 have been *the norm*, 4 lesser so, and
recently a few 6s have cropped up.

geoff

[[email protected]]

geoff wrote: "3:17 PMgeoff
- show quoted text -
In reply to my comment about the extreme rarity of (specifically) 16 ohm
speakers since the mid-'70s (probably earlier) , your comment seemed to
imply that I thought your 8 ohm speakers were some sort of rarity.

Whereas since solid-state days 8 have been *the norm*, 4 lesser so, and
recently a few 6s have cropped up.

geoff "

Sorry if my comment in that thread was vague. Actually, I implied that you thought my 8-16ohm-accepting JVC receiver was some sort of rarity, or cheap.


So if I read your statement above correctly, it seems there is a centering of impedances between 6-8ohms recently, with 16 almost nonexistent and 4ohms becoming so.

[None]

wrote in message
...
... most built in the last 20 years ... calls for 8-16ohm loads.

Mostly the crap ones.

[gregz]

wrote:
geoff wrote: "- show quoted text -
Or good at readingf comprehension, it seems!

"16 ohms". SIXTEEN !

Seen any in the last 40 years ?

geoff "

I am not always reading this from a desktop. All I did was state the
range of acceptable speaker impedance(8-16) listed on the back of my receiver.

Who has this "reading comprehension" problem you repeatedly point to?

I bought a bunch mid 90s, and supposed to be for MTM which is what I used
them for. Parallel 16s.

Greg

[geoff]

On 8/12/2014 9:24 a.m., wrote:
geoff wrote: "3:17 PMgeoff
- show quoted text -
In reply to my comment about the extreme rarity of (specifically) 16 ohm
speakers since the mid-'70s (probably earlier) , your comment seemed to
imply that I thought your 8 ohm speakers were some sort of rarity.

Whereas since solid-state days 8 have been *the norm*, 4 lesser so, and
recently a few 6s have cropped up.

geoff "

Sorry if my comment in that thread was vague. Actually, I implied that you thought my 8-16ohm-accepting JVC receiver was some sort of rarity, or cheap.


So if I read your statement above correctly, it seems there is a centering of impedances between 6-8ohms recently, with 16 almost nonexistent and 4ohms becoming so.



No. 4 or 8 are the common specs, but the spec is for the minimum load
impedance, so ann amp specced at 8 ohms *may* have trouble with a 6 ohm
load on peaks, but a 4 ohm output won't have any problem at all..

And 16 doesn't matter - if your amp will do the lower ones, it'll be
just fine with a lesser load (= higher Z).

geoff

[Mark Zacharias]

"geoff" wrote in message
...
On 7/12/2014 1:01 p.m., Mark Zacharias wrote:

Trevor.




What I meant to suggest is that so-called "8-ohm" speakers have always
actually been closer to 5 or 6 ohms. Should have been clearer.

mz

That is equally false. An 8 ohm driver will often have a DC RESISTANCE
often around 6 ohms, but it's impedance will likely be very different, and
change with frequency.

Then throw in a crossover network and you'll have even wider variation.


geoff


Exactly. If you plot the impedance curve of an 8-ohm speaker, the impedance
will generally, but not always, drop below 5 ohms at resonance. This has
been true for over 40 years.

When I said impedance, I meant impedance, not DC resistance.

This is getting to be just tiresome nit-picking. You aren't even making a
distinction here, because I essentially said the SAME thing.


Mark Z.

[geoff]

On 10/12/2014 12:31 a.m., Mark Zacharias wrote:
"geoff" wrote in message
...
On 7/12/2014 1:01 p.m., Mark Zacharias wrote:

Trevor.




What I meant to suggest is that so-called "8-ohm" speakers have always
actually been closer to 5 or 6 ohms. Should have been clearer.

mz

That is equally false. An 8 ohm driver will often have a DC
RESISTANCE often around 6 ohms, but it's impedance will likely be very
different, and change with frequency.

Then throw in a crossover network and you'll have even wider variation.


geoff


Exactly. If you plot the impedance curve of an 8-ohm speaker, the
impedance will generally, but not always, drop below 5 ohms at
resonance. This has been true for over 40 years.

When I said impedance, I meant impedance, not DC resistance.

This is getting to be just tiresome nit-picking. You aren't even making
a distinction here, because I essentially said the SAME thing.


Mark Z.


"5 or 6 ohms" is a bit specific for impedance, - which could be over a
wider range. DC resistance is almost universally around 6.3
ohms....ish. But less "ish" than your impedance figure.

But we are splitting hairs, so let's drop it.

geoff

[[email protected]]

geoff wrote: "- show quoted text -
No. 4 or 8 are the common specs, but the spec is for the minimum load
impedance, so ann amp specced at 8 ohms *may* have trouble with a 6 ohm
load on peaks, but a 4 ohm output won't have any problem at all..

And 16 doesn't matter - if your amp will do the lower ones, it'll be
just fine with a lesser load (= higher Z).

geoff "

So you're saying that I can safely hook up speakers with a 4ohm sticker on the back to my 8-16ohm receiver, but not a 6ohm. Clear as mud to me, but I'll trust you on this.

[Peter Larsen[_3_]]

skrev i en meddelelse
...

geoff wrote: "- show quoted text -
No. 4 or 8 are the common specs, but the spec is for the minimum load
impedance, so ann amp specced at 8 ohms *may* have trouble with a 6 ohm
load on peaks, but a 4 ohm output won't have any problem at all..

And 16 doesn't matter - if your amp will do the lower ones, it'll be
just fine with a lesser load (= higher Z).

geoff "

So you're saying that I can safely hook up speakers with a 4ohm
sticker on the back to my 8-16ohm receiver, but not a 6ohm.

Your 8 to 16 ohm receiver is probably spec'ed like that because of the cost
of iron and electrolytic capacitors required for a proper powersupply.

I am however not making any guarantee of what it will and will not tolerate,
generally a transistor amplifier comes with circuitry to protect it from
excessive current demand. There are idiotic exceptions, but if the required
protection circuit messes unduly with the sound then the output transistors
were chosen to fit the budget from the sales department rather than the
design requirements.

Generally for an amplifier for home use I'd expect 60 percent more output
power specified for each halving of load impedance because that is the
design choice that _tends_ to allow largest unclipped peak power, no promise
made.

Way back in time somebody tested output power of a number of large power
amplifiers in real loudspeaker loads, I think the worst result was held by a
300 watt amplifier that went into current limiting at 11 watts in a real
world loudspeaker, I also think I remember the brand but they probably do
not make them like that now so it is intentionally omitted.

Clear as mud to me, but I'll trust you on this.

Lower Z = higher load (current demand).

Kind regards

Peter Larsen

[geoff]

On 10/12/2014 1:19 a.m., wrote:
geoff wrote: "- show quoted text -
No. 4 or 8 are the common specs, but the spec is for the minimum load
impedance, so ann amp specced at 8 ohms *may* have trouble with a 6 ohm
load on peaks, but a 4 ohm output won't have any problem at all..

And 16 doesn't matter - if your amp will do the lower ones, it'll be
just fine with a lesser load (= higher Z).

geoff "

So you're saying that I can safely hook up speakers with a 4ohm sticker on the back to my 8-16ohm receiver, but not a 6ohm. Clear as mud to me, but I'll trust you on this.


Clearly "clear as mud".

NO. You should not hook up a speaker with a lower Z than your amp is
specified to drive. Higher Zs are no problem.


geoff