Line in and mic in

Archived from groups: comp.sys.laptops (More info?)

On Sat, 5 Jun 2004 14:18:55 +0100, "Cocklebury Farm"
<cocklebury.farm@virgin.net> wrote:

>Hi,
>
>Can anyone tell me if there is a difference between line in and microphone
>in sockets on a laptop? I've noticed that some come with both and some only
>have mic in. Is there a difference in quality when making recordings etc?
>
>Cheers,
>
>Richard
>
>

Line in will usually be stereo and about 10Kohm impendence.

Mic is mono and about 600-1Kohm impendence and expecting SIGNIFICANTLY
lower levels than the line, as it has a preamp to pick up the very low
levels present in a microphone.

Providing you get the levels right, there should be no difference in
quality and it will depend on what source you are recording from - If
line, would strongly recommend matching it to a line, thus avoiding
impendence mis-match and having to adjust levels.


Jim

Archived from groups: comp.sys.laptops (More info?)

On Sat, 5 Jun 2004 16:57:02 -0700, "Richard Johnson"
<richj@remove.this.tairedd.com> wrote:

>Line in is usually a low impedance input load. Thus requires an audible
>signal. (One that you would put to a standard set of stereo headphones or
>directly to a speaker.)

Nope. LIne In is usually on the order of a volt or so and at
impedance levels of a few hundred to a few K of ohms. This will not
drive speakers which are rarely more than 10ohms and many volts.

>The mic in is usually a high impedance input.

Generally, higher than speaker or line level.

>Meant for something with a voltage output but can't deliver significant
>power. So, they are not the same. Put a mic into a line in and you will
>not get much out of the speakers. Put it in the mic in and volume will be
>normal. Put a line into the mic input you risk overdriving your internal
>amplifier. Result will be distortion and possibly a fried internal amp (Not
>likely but possible.)

OK.

Kal

Archived from groups: comp.sys.laptops (More info?)

There is a difference. Line in is a relatively high-level input with no
(or "flat" ) equalization. Mic in could be for either of two kinds of
microphones, dynamic or capacitance. If dynamic, it's a very low-level
input (millivolts) and it may have a frequency response very different
from "flat". If it a capacitance input, it supplies a bias voltage to
the microphone, and accepts a different type of microphone (dynamic and
capacitance microphones are not interchangeable).

In general, a mic input should only be used with a microphone, although
with a suitable attenuating and equalizing network, it's possible to
feed a line-level signal into a mic input (note, however, ONLY with a
suitable attenuating and possibly equalizing network).

Since most laptops do not have line inputs (much to my personal
distress, I might add), if you want to do any serious audio work with a
laptop, you really need an externa USB sound system (I was going to say
"sound card", but that isn't really right).


Cocklebury Farm wrote:

> Hi,
>
> Can anyone tell me if there is a difference between line in and microphone
> in sockets on a laptop? I've noticed that some come with both and some only
> have mic in. Is there a difference in quality when making recordings etc?
>
> Cheers,
>
> Richard
>
>
>

Archived from groups: comp.sys.laptops (More info?)

Barry Watzman wrote:
> There is a difference. Line in is a relatively high-level input with no
> (or "flat" ) equalization. Mic in could be for either of two kinds of
> microphones, dynamic or capacitance. If dynamic, it's a very low-level
> input (millivolts) and it may have a frequency response very different
> from "flat". If it a capacitance input, it supplies a bias voltage to
> the microphone, and accepts a different type of microphone (dynamic and
> capacitance microphones are not interchangeable).
>
> In general, a mic input should only be used with a microphone, although
> with a suitable attenuating and equalizing network, it's possible to
> feed a line-level signal into a mic input (note, however, ONLY with a
> suitable attenuating and possibly equalizing network).
>
> Since most laptops do not have line inputs (much to my personal
> distress, I might add), if you want to do any serious audio work with a
> laptop, you really need an externa USB sound system (I was going to say
> "sound card", but that isn't really right).
>
>
> Cocklebury Farm wrote:
>
>> Hi,
>>
>> Can anyone tell me if there is a difference between line in and
>> microphone
>> in sockets on a laptop? I've noticed that some come with both and
>> some only
>> have mic in. Is there a difference in quality when making recordings
>> etc?
>>
>> Cheers,
>>
>> Richard
>>
>>
>>
>
Hi,
Most common mic. for PC is electret type. Line in is usually 600 Ohm
impedance. You can make a simple L pad(attenuator) and use mic. input
for whatever source. My boy uses Toshi Satellite PIII 850MHz laptop for
extensive music recording and I rigged up a simple L pad to use the mic.
input jack. Do a search on Google for L pad.
Need 3 resistors and simple soldering.
Tony, VE6CGX