Replacement Cabin Speaker for Cessna?

You ever see a Farmall spin accident? It ain't pretty.

"Roy Smith" wrote in message
...

Jim,

You must be the only guy I know who owns a tractor with a stall
warning horn :-)

Yes, good idea!

Cessna is backordered for that part til late January, so I'm gonna have
to do something. For a stopgap I may just put in a standard speaker
and hook only the gear/stall horn to it. I use headphones for my comm
audio anyway...

Thanks,
John

What size is the original speaker? 4"x6" ? Find out if it is a common
automotive speaker size. Go to your local electronics closeout store or
online catalog place and find a 2-way or 3-way speaker that will fit in the
original opening. What I propose is similar in thought to Jim's idea.

With a little electronics know-how, you can electrically seperate the main
cone (woofer) from the tweeter. Use the main cone for the voice from the
comm, and the smaller for the stall horn. Since most car audio stuff is 4
ohm, you might want to put a resistor in series with the speaker so you
don't cook the audio amp in your radio.

--
Hello, my name is Mike, and I am an airplane addict....

"Mike W." wrote in message ...
What size is the original speaker? 4"x6" ? Find out if it is a common
automotive speaker size. Go to your local electronics closeout store or
online catalog place and find a 2-way or 3-way speaker that will fit in the
original opening. What I propose is similar in thought to Jim's idea.

With a little electronics know-how, you can electrically seperate the main
cone (woofer) from the tweeter. Use the main cone for the voice from the
comm, and the smaller for the stall horn. Since most car audio stuff is 4
ohm, you might want to put a resistor in series with the speaker so you
don't cook the audio amp in your radio.


Hello Mike,

Mine is round, 5.25 inch. My Radio Shack is a mall outlet, no components, but I found a speaker at-- get
this-- Walmart!

Thats a good idea about the 2 way speaker. By "electrically separate the main cone from the tweeter", do you
mean they will have the 4 teensy wires coming from the coils to 2 terminals on terminal strip, and I will just
need to snip the proper ones and provide separate terminal connection to it? I do think I could handle that!

I believe my existing speaker is 4 ohms also. At least it measures about 4 ohms with my cheap DVM-- but I know
that's just measuring its DC resistance, how can I tell what its impedance is? (My electronics experience is
mostly in digital!)


Thanks!
John

"John Clonts" writes:


Yes, good idea!

Cessna is backordered for that part til late January, so I'm gonna have
to do something. For a stopgap I may just put in a standard speaker
and hook only the gear/stall horn to it. I use headphones for my comm
audio anyway...


I was going to ask that next: does anyone listen to comm on
a speaker anymore?

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"John Clonts" writes:



I believe my existing speaker is 4 ohms also. At least it measures about 4 ohms with my cheap DVM-- but I know
that's just measuring its DC resistance, how can I tell what its impedance is? (My electronics experience is
mostly in digital!)

A) Use an impedence bridge.

B) SWAG it with a ~20 ohm pot and an audio generator. Put the pot in series and adjust it
until the voltage drop is ~equal across the speaker and pot. Shut down and measure the
pot's resistance.

Of course, the speaker impedence is nowhere near flat vs. frequency; and further, it's
never going to be close to what the label says.....

And if whatever works with a ""4 ohm"" speaker, a 8 ohm will work almost as well.


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

If your speaker is like most 2-way auto speakers, the tweeter is mounted on
a little plastic 'bridge' in front of the main speaker cone. The wires that
run to the tweeter will run up the legs of the bridge. So, yes figure out
where to cut those wires and solder your wires onto those. One other thing
to look for is a capacitor connected to the tweeter, it is the 'crossover'
basically it filters out frequencies below a certain point, maybe 5000 Hz.
Keep that in the circuit with the tweeter. So with a little work you will
have two speakers in one.
If your existing speake measures near 4 ohms you should be fine. Not like a
comm has a high-current audio amp in it.

"John Clonts" wrote in message
...

Hello Mike,

Mine is round, 5.25 inch. My Radio Shack is a mall outlet, no components,
but I found a speaker at-- get
this-- Walmart!

Thats a good idea about the 2 way speaker. By "electrically separate the
main cone from the tweeter", do you
mean they will have the 4 teensy wires coming from the coils to 2
terminals on terminal strip, and I will just
need to snip the proper ones and provide separate terminal connection to
it? I do think I could handle that!

I believe my existing speaker is 4 ohms also. At least it measures about
4 ohms with my cheap DVM-- but I know
that's just measuring its DC resistance, how can I tell what its impedance
is? (My electronics experience is
mostly in digital!)


Thanks!
John

David Lesher wrote:
: I was going to ask that next: does anyone listen to comm on
: a speaker anymore?

"WHAT? WHAT'S THAT YOU SAY? SPEAK UP"



-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

Mine is round, 5.25 inch. My Radio Shack is a mall outlet, no components, but I found a speaker at-- get
this-- Walmart!

Don't ignore the advice from a previous poster about checking the magnet.
Someone put a RadioShack speaker in my ol' Cherokee once and it definitely had
an effect on the compass. I took it out and put in a genuine Piper part (or
anyway one with a weaker magnet, I don't remember any more).

You get an audio generator and an AC voltmeter. (Be careful of the el
cheapo digital voltmeters that don't have a frequency response much above
500 Hz.) You also get a variable resistor of 25 ohms or so. You put the
generator on 1000 Hz. and adjust the resistor so that there is as much
voltage across the resistor as there is across the speaker. Remove the
resistor and read it with the dvm.

Jim


I believe my existing speaker is 4 ohms also. At least it measures about
4 ohms with my cheap DVM-- but I know that's just measuring its DC
resistance, how can I tell what its impedance is? (My electronics
experience is mostly in digital!)


Thanks!
John