Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Thanks,

Vasilis

In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4 Ohm
ones may draw more current, and that some amplifiers may not like this.
However the specific 4 Ohm speakers in a given case may not require as
large a voltage to play at a given sound level as some other 8 Ohm pair,
and you amplifiers may be quite happy to drive them. Hence even this
general comment isn't necessarily relevant to models you have in mind.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

"Jim Lesurf" wrote in message
...
In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4 Ohm
ones may draw more current, and that some amplifiers may not like this.

By the way, some manufacturers offer near-identical speakers in 4-ohm and
8-ohm versions, with otherwise similar specifications.. Does anyone know
how they do this ... is there some simple trick to it?

Tim

On Tue, 17 May 2005 12:36:17 GMT, "Tim Martin"
wrote:


"Jim Lesurf" wrote in message
...
In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4 Ohm
ones may draw more current, and that some amplifiers may not like this.

By the way, some manufacturers offer near-identical speakers in 4-ohm and
8-ohm versions, with otherwise similar specifications.. Does anyone know
how they do this ... is there some simple trick to it?

Tim


Fewer turns of thicker wire on the 4 ohm unit.

d

Pearce Consulting
http://www.pearce.uk.com

"Don Pearce" wrote in message
...
On Tue, 17 May 2005 12:36:17 GMT, "Tim Martin"
wrote:


"Jim Lesurf" wrote in message
...
In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4
Ohm
ones may draw more current, and that some amplifiers may not like this.

By the way, some manufacturers offer near-identical speakers in 4-ohm and
8-ohm versions, with otherwise similar specifications.. Does anyone know
how they do this ... is there some simple trick to it?

Tim


Fewer turns of thicker wire on the 4 ohm unit.


Yes, production cost-cutting exercises mainly - I've been thinking that and
waiting to see someone else post it....

On Tue, 17 May 2005 12:36:17 GMT, "Tim Martin"
wrote:

"Jim Lesurf" wrote in message
...
In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

*In theory*, a 4-ohm speaker can be more efficient, but that may not
apply in practice. What *is* universally true is that, since the
'official' dB/w/m sensitivity is measured with a 2.828 vrms input - a
nominal 1 watt at 8 ohms - a 4-ohm speaker immediately gains a 3dB
hike in its spec-sheet sensitivity compared to a true 8-ohm speaker.
Some manufacturers like the look of this in the sales blurb.

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4 Ohm
ones may draw more current, and that some amplifiers may not like this.

Very few decent SS amps have a problem with a 4-ohm load. Tube amps,
of course, always have a problem, as they are rated to put out the
same power pretty much regardless of load, so you get 3dB less sound
level with a 4-ohm speaker, if you use the 4-ohm taps rather than the
8-ohm taps on the output transformer.

By the way, some manufacturers offer near-identical speakers in 4-ohm and
8-ohm versions, with otherwise similar specifications.. Does anyone know
how they do this ... is there some simple trick to it?

Different motor assemblies in the drivers, with fewer turns and/or
thicker wire on the 4-ohm units.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

On Tue, 17 May 2005 14:50:04 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
...
On Tue, 17 May 2005 12:36:17 GMT, "Tim Martin"
wrote:


"Jim Lesurf" wrote in message
...
In article .com,
wrote:
Hi,

Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

Depends entirely on the speakers in question, the equipment you use them
with, and your personal tasts/circumstances.

The only general comment is that *for the same applied voltage* the 4
Ohm
ones may draw more current, and that some amplifiers may not like this.

By the way, some manufacturers offer near-identical speakers in 4-ohm and
8-ohm versions, with otherwise similar specifications.. Does anyone know
how they do this ... is there some simple trick to it?

Tim


Fewer turns of thicker wire on the 4 ohm unit.


Yes, production cost-cutting exercises mainly - I've been thinking that and
waiting to see someone else post it....

It also makes the coil lighter in most cases, which can lead to
genuinely immproved efficiency. It's not *all* about cost-cutting, and
of course it gives you a bigger number for the spec-sheet sensitivity,
which automatically goes up by 3dB.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Owain" wrote in message
...
wrote:
Can you please tell me the advantages and disadvantages of 4 ohm
compared to 8 ohm loudspeakers?

An amp(lifier) will deliver more power into 4 ohm speakers than into 8
ohm speakers.

An amp will run hotter when delivering more power into 4 ohm speakers.
Most amps will cope.

Owain

[1] Assuming lots of assumptions about speaker impedance here.



I didn't know about an amp running hotter when delivering more power into 4
ohms. A worryingly obvious lack of knowledge on my part. Good news when
you've got a 70's monster receiver that loves to impersonate a "bar element"
heater and perform significantly better(as an amp, not better than a bar
heater) when doing so.