Should the speaker diaphragm face out or in to the sound chamber?

[Bill H]

Group;
I have read divergent opinions and seen differing images reflecting on whether the speaker diaphragm face out or in to the sound chamber. Others have opined it makes no difference? Thoughts and experiences?

Thanks,
Bill

[peteski]

We had fee discussions about this here some time ago. While not intuitive, it doesn't seem to make a difference.

https://www.therailwire.net/forum/index.php?topic=51356.0
https://www.therailwire.net/forum/index.php?topic=59060.0
https://www.therailwire.net/forum/index.php?topic=42483.0

There were probably few others too.

[Bill H]

Hi Peteski;
I remembered those discussions, I was sort of hoping that by now some sort of consensus had been reached as to best practice. Indeed it does seem counter intuitive.

Kind regards,
Bill

[kiwi_bnsf]

Hi Bill,

I did some fairly extensive (obsessive?) testing of speaker orientation and speaker chamber design options that are covered here:

          New Adventures in Loco Hi-Fi
          https://www.therailwire.net/forum/index.php?topic=55532.0

This thread includes comparison videos using the same controlled environment and microphone setup.

Many of these cell phone speakers have been explicitly designed to be mounted firing inwards — hence the smooth surround around the outside of the driver (sometimes with an adhesive tape strip pre-applied). The spring contacts or solder tabs face outwards for convenient connections without having to seal any holes in the enclosure.

Speaker testing is very subjective, but I'm convinced from my testing that inward firing is the best option, and I've been happy with the results from all my subsequent designs.

Hope that this helps.

Cheers

[Sumner]

Hi Peteski;
I remembered those discussions, I was sort of hoping that by now some sort of consensus had been reached as to best practice. Indeed it does seem counter intuitive.

Kind regards,
Bill

All of the ones I've installer in engines or other projects are faced in.....so from the posts so far a consensus has been reached 

Sumner

[tehachapifan]

I mount them facing inward as well. An added benefit in doing it this way is, if done correctly, the diaphragm is completely protected from damage or from something pressing on it.

[Bill H]

Thanks to all who replied. All my planned installations will be facing inwards.

Kind regards,
Bill