Impedance and amps
 

I'm looking at fitting some speakers I have lying around to my car. The
thing is, car headunits usually have wattage quoted for with 4ohm speakers.
The speakers I have at 6 ohm. Is this going to lead to a noticeable lack of
volume running a boggo head unit that nominally throws out 25-30WPC RMS, or
am I just going to lose the top end of the range of clipped distorted car
radio horribleness?

Impedance and amps
 

"Doki" wrote in message
...
I'm looking at fitting some speakers I have lying around to my car. The
thing is, car headunits usually have wattage quoted for with 4ohm
speakers. The speakers I have at 6 ohm. Is this going to lead to a
noticeable lack of volume running a boggo head unit that nominally throws
out 25-30WPC RMS, or am I just going to lose the top end of the range of
clipped distorted car radio horribleness?

**No.

BTW: The vast majority of head units deliver around 4 Watts or 16 Watts
continuous (aka: RMS) per channel. Only units which have internal inverters
can deliver more power than this. Usually, this would be an external power
amp. Manufacturer who claim more are usually telling fibs. The 4 Watt rated
units (rare today) use a standard push pull amp. The 16 Watt units use a
bridged output stage.

Trevor Wilson

Impedance and amps
 

Doki wrote:

I'm looking at fitting some speakers I have lying around to my car. The
thing is, car headunits usually have wattage quoted for with 4ohm speakers.

Indeed.


The speakers I have at 6 ohm. Is this going to lead to a noticeable lack of
volume running a boggo head unit that nominally throws out 25-30WPC RMS, or
am I just going to lose the top end of the range of clipped distorted car
radio horribleness?

You are going to lose about 1.5dB. In other words the loss in power will be
virtually inaudible.

If the 6 ohm speakers are more efficient (see the dB/W @ 1m figures) then it
might even be louder with them.

Speaker efficiency is far more important than a few ohms difference in the
impedance or a few extra watts.

Graham

Impedance and amps
 

In article ,
Trevor Wilson wrote:
BTW: The vast majority of head units deliver around 4 Watts or 16 Watts
continuous (aka: RMS) per channel. Only units which have internal
inverters can deliver more power than this. Usually, this would be an
external power amp. Manufacturer who claim more are usually telling
fibs. The 4 Watt rated units (rare today) use a standard push pull amp.
The 16 Watt units use a bridged output stage.

You could get more power by using an output transformer - Blaupunkt did
this when they were Blue Spot. ;-) Takes up rather a lot of room though.
Or, of course, use lower than 4 ohm speakers.

There's a DIN standard for fiddled power output. 45324. Allows you to
claim 26 watts when it's actually 18 at 1% distortion.

--
*Frankly, scallop, I don't give a clam

Dave Plowman London SW
To e-mail, change noise into sound.

Impedance and amps
 

"Dave Plowman (News)" wrote in message
...
In article ,
Trevor Wilson wrote:
BTW: The vast majority of head units deliver around 4 Watts or 16 Watts
continuous (aka: RMS) per channel. Only units which have internal
inverters can deliver more power than this. Usually, this would be an
external power amp. Manufacturer who claim more are usually telling
fibs. The 4 Watt rated units (rare today) use a standard push pull amp.
The 16 Watt units use a bridged output stage.

You could get more power by using an output transformer - Blaupunkt did
this when they were Blue Spot. ;-) Takes up rather a lot of room though.
Or, of course, use lower than 4 ohm speakers.

**Indeed. Which is why I wrote: "....vast majority of HEAD UNITS..."
(emphasis added). I used to own a transformer coupled power amp (for my car)
which was rated at 150 Watts RMS (sic). It delivered a fairly credible 60
Watts continuous, however. Of course, it sounded like crap.


There's a DIN standard for fiddled power output. 45324. Allows you to
claim 26 watts when it's actually 18 at 1% distortion.

**Like I said: 16 Watts continuous is about it.

Trevor Wilson

Impedance and amps
 

"Eeyore" wrote in message
...


Doki wrote:

I'm looking at fitting some speakers I have lying around to my car. The
thing is, car headunits usually have wattage quoted for with 4ohm
speakers.

Indeed.


The speakers I have at 6 ohm. Is this going to lead to a noticeable lack
of
volume running a boggo head unit that nominally throws out 25-30WPC RMS,
or
am I just going to lose the top end of the range of clipped distorted car
radio horribleness?

You are going to lose about 1.5dB. In other words the loss in power will
be
virtually inaudible.

If the 6 ohm speakers are more efficient (see the dB/W @ 1m figures) then
it
might even be louder with them.

Speaker efficiency is far more important than a few ohms difference in the
impedance or a few extra watts.

No idea regarding efficiency - they're coming out of a scrap Jag, and IIRC
efficiency is related to enclosure as well as just the driver. I do know
that they sound good, which I all I'm really bothered with.

Impedance and amps
 

Doki wrote:

"Eeyore" wrote in message

Speaker efficiency is far more important than a few ohms difference in the
impedance or a few extra watts.

No idea regarding efficiency - they're coming out of a scrap Jag, and IIRC
efficiency is related to enclosure as well as just the driver. I do know
that they sound good, which I all I'm really bothered with.

The enclosure will only significantly affect low fequency performance, not mid
or high frequency (unless it's a horn!).

Graham