Interior lights and speaker

[Mooney5]

I am searching for the cabin speaker and cabin lighting for a 1970 Mooney M20c. Any suggestions? 

[N201MKTurbo]

5 minutes ago, Mooney5 said:

I am searching for the cabin speaker and cabin lighting for a 1970 Mooney M20c. Any suggestions? 

I would look over your head.

[N201MKTurbo]

Sorry, I couldn’t help myself….

[EricJ]

22 minutes ago, Mooney5 said:

I am searching for the cabin speaker and cabin lighting for a 1970 Mooney M20c. Any suggestions? 

I replaced the speaker in my J model a couple years ago and had to just get a rough equivalent of the original, which was a Radio Shack (Realistic) generic model that is no longer made.  A modern speaker will be much better, anyway.   It really just needs to be the right size so that it fits, proper impedance, and comparable power capability.

This is what I wound up using, but your airplane may be different.

https://www.amazon.com/gp/product/B01N4NY1KE

 

[Utah20Gflyer]

I don’t know for sure but the speaker in my plane looks like a generic speaker you would buy off Amazon,or could be a factory Mooney speaker.  I have no way of knowing the difference.   You might ask your mechanic what they think of potential sources for speakers.   They may be fine with any speaker that matches the specifications of the original.  

[Hank]

9 hours ago, Mooney5 said:

I am searching for the cabin speaker and cabin lighting for a 1970 Mooney M20c. Any suggestions? 

Why? Do you not use a headset? Nothing comes out of my speaker, the stall warning and gear warning have their own tiny units (sonalerts).

[GeeBee]

Headsets, and their jacks can fail. A wired in speaker is your back up.

[wombat]

Everything can fail. What the cost of and success rate is of a backup or convenience of having the thing compared to your personal budget for cost (Including weight and complexity) and risk of the various outcomes plus any legal requirements dictate if you need a backup of a thing.

 

Do you personally value the extra 3/4" (or whatever it is) of cabin height that the speaker consumes, and/or the weight penalty and extra wiring and potential for failure a lot?

Or do you place a higher value on the convenience of being able to listen to the radio prior to putting your headset on, or having a different way to listen to radios if your audio system has some relatively specific types of failures?

 

If there is no legal requirement, then you get to decide!  What fun!

 

When I'm feeling risk-averse, I won't fly anything with less than 17 engines where each engine has it's own parachute plus a backup parachute.    But sometimes I am willing to accept risk and I'll just go fly with only the left wing and one prop blade, because I just can't deal with the performance hit of all that drag.

 

More seriously, if there is no requirement one way or the other, then do whatever you think is best!

[Hank]

1 hour ago, wombat said:

Do you personally value the extra 3/4" (or whatever it is) of cabin height that the speaker consumes, and/or the weight penalty and extra wiring and potential for failure a lot?

Or do you place a higher value on the convenience of being able to listen to the radio prior to putting your headset on, or having a different way to listen to radios if your audio system has some relatively specific types of failures?

The speaker is above the headliner, so ceiling height is not affected by its presence or absence.

I carry a handheld radio as my backup in the event of another total electrical failure, or just the intercom crapping out. It works well for pre-start radio listening, too.

I was curious why @Mooney5 wanted a new speaker. Until recently, I didn't even know my C had an interior light, always having used flashlights at night if the red heaters in the ceiling didn't throw enough light around for me.

[wombat]

On my 182 the speaker pushes the headliner down, so if I removed the speaker, I'd gain some space.  I didn't know what the headliner situation in a M20C is regarding the speaker.   If you took it out you might be able to shove the  headliner up into that newly-empty space?   Or maybe the speaker is mounted behind a piece of sheet metal?  I don't know.

But the comment about the space it takes up was really a stand-in for any factor that makes a thing less desirable.   Maybe it takes up space, maybe it takes time to preflight or maintain, maybe it just adds weight or expense.

Edited May 25, 2023 by wombat

[Hank]

12 minutes ago, wombat said:

On my 182 the speaker pushes the headliner down, so if I removed the speaker, I'd gain some space.  I didn't know what the headliner situation in a M20C is regarding the speaker.   If you took it out you might be able to shove the  headliner up into that newly-empty space?   Or maybe the speaker is mounted behind a piece of sheet metal?  I don't know.

But the comment about the space it takes up was really a stand-in for any factor that makes a thing less desirable.   Maybe it takes up space, maybe it takes time to preflight or maintain, maybe it just adds weight or expense.

No, the headliner is formed plastic like the sidewalls, and the speaker is mounted between the front overhead air vents--no space savings from removal. Mine is still there, I just don't know how to make it work, I'd have to play with the intercom and see.

The old microphone clip is still one the A pillar, and is a good storage location for hanging a AA Mini Maglite.  

[Marc_B]

I seem to remember seeing this at Lasar. Not sure the PN of what your looking for…

https://lasar.com/electrical-instruments/cabin-speaker-pyle-plx-32
 

might be worth a call to Lasar to see if they can confirm part number and availability. 

[Pinecone]

13 hours ago, Hank said:

Mine is still there, I just don't know how to make it work, I'd have to play with the intercom and see.

The old microphone clip is still one the A pillar, and is a good storage location for hanging a AA Mini Maglite.  

I know mine works, when my shop installed my Landing Height System, they left it in Speaker on the audio panel.

My microphone is still in the clip.  It makes a nice place to hang the O2 hoses.

[GeeBee]

You only need to be NORDO once because of a jack short to realize the value of a speaker. Because with a jack short, even an extra headset won't bail you out, nor will jacking into another jack, because they are all on the same circuit. Had one in my PA-18. Not only are you NORDO, you can't communicate with your passengers .

It's cheap, it's light and it's easy. It is not like adding another engine.

[EricJ]

On 5/26/2023 at 5:17 AM, GeeBee said:

You only need to be NORDO once because of a jack short to realize the value of a speaker. Because with a jack short, even an extra headset won't bail you out, nor will jacking into another jack, because they are all on the same circuit. Had one in my PA-18. Not only are you NORDO, you can't communicate with your passengers .

That's not true with many of the modern audio panels.    They can route different music/entertainment channels to different stations, and isolate them separately, so they're on separate circuits.

[GeeBee]

The OP has an M20C

[Hank]

4 hours ago, GeeBee said:

The OP has an M20C

Depends on the intercom installed. My C doesn't have any factory electronics in it any more, and hasn't for decades.

[GeeBee]

So does it have a separate channels for each station?

 

[Hank]

3 hours ago, GeeBee said:

So does it have a separate channels for each station?

 

My C has separate headset plugs for each seat, and I think PS8000 intercom.

[GeeBee]

9 hours ago, Hank said:

My C has separate headset plugs for each seat, and I think PS8000 intercom.

From the PS8000 installation manual (FAA Approved):

 

EQUIPMENT REQUIRED BUT NOT SUPPLIED

Circuit Breaker: 1 ea.; 5 amp PULL TYPE REQUIRED for PMA8000G

Speaker, 4 ohm
Headphone Jacks (Stereo, as Required)
Microphone Jacks (as Required)

Headphones, 150  (Stereo), up to 6 as required
Microphones, up to 6 as required
Marker Antenna (75 MHz, VSWR <1:1.5, and appropriate for the airspeed) Interconnect Wiring

The manual further states:

Failure to follow any of the installation instructions, or installation by a non-certified individual or agency will void the warranty, and may result in an unairworthy installation.

[EricJ]

2 hours ago, GeeBee said:

From the PS8000 installation manual (FAA Approved):

 

EQUIPMENT REQUIRED BUT NOT SUPPLIED

Circuit Breaker: 1 ea.; 5 amp PULL TYPE REQUIRED for PMA8000G

Speaker, 4 ohm
Headphone Jacks (Stereo, as Required)
Microphone Jacks (as Required)

Headphones, 150  (Stereo), up to 6 as required
Microphones, up to 6 as required
Marker Antenna (75 MHz, VSWR <1:1.5, and appropriate for the airspeed) Interconnect Wiring

The manual further states:

Failure to follow any of the installation instructions, or installation by a non-certified individual or agency will void the warranty, and may result in an unairworthy installation.

From the Op Manual for the PS8000:

Push button switches selects one of the communication transceivers for the pilot and copilot position, and allows radio transmission. In "Split Mode" the PMA8000 has the ability to allow the pilot to transmit on com 1 while the copilot can transmit on com 2. A fail-safe mode connects the pilot headphone and microphone to COM 1 if power is removed for any reason, or if the power switch is placed in the Off (Fail-safe) position.

...

The intercom system incorporates pilot isolate, all and crew modes, two independent stereo music inputs with "Soft Mute," and flashing LED indications for transmit indications. Intercom control is through two concentric front panel volume controls and a pushbutton intercom mode switch. The small volume knob controls the intercom level for the pilot and copilot, while the large knob controls the passenger intercom volume. Intercom squelch is automatic

Many modern audio panels have split modes and isolation modes and entertainment distribution that can be selected differently for different stations.    The G1000 does this, too.   This means that the headsets are wired independently, so a jack short or stuck mic on the pilot or co-pilot won't affect the other.

[GeeBee]

Still does not remove the requirement for a speaker, does it?

[EricJ]

7 minutes ago, GeeBee said:

Still does not remove the requirement for a speaker, does it?

Just clarifies it's not due to mitigating a jack short.

[GeeBee]

I'm not an EE nor am I privy to the details of the design, but clearly they want a speaker for some reason and I would guess they have identified that failure mode which none of us have considered. I would also add many newer flight decks like the G1000 require a speaker as a back up for the aural warnings such as stall and gear.

 

[EricJ]

2 minutes ago, GeeBee said:

I'm not an EE nor am I privy to the details of the design, but clearly they want a speaker for some reason and I would guess they have identified that failure mode which none of us have considered. I would also add many newer flight decks like the G1000 require a speaker as a back up for the aural warnings such as stall and gear.

The utility of a speaker is pretty obvious, and an obvious failure mode that it will mitigate is the failure of a headset during single-pilot operation.