Miniature Speaker Selection

[JoshuaGates]

Hi Everyone,

Just working on a new project with a probe that will be inserted into a void space (maybe defined as a 2m cube).
The probe will be inserted through a 35mm hole so that is the definition of miniature speaker I am going for.
The operator will be able to use a microphone from their laptop which will be outputted to the miniature speaker in the void which I will probably just hook up to a 3.5mm audio jack.

The question then becomes how do I select the miniature speaker?
I was looking on RS Components for speakers within the size requirement with the highest rated power (1.5W best I could find)
however the frequency range is then limited to 7kHz and I understand audible sound goes to 20kHz. I'm trying to avoid obtaining sound similar to that of earbuds on max where it's too quiet so more toward like a cellphone on speaker phone hence was looking at the rated power. Any advice on this project would be brilliant.

Trying to google my queries just brings about links to do with public speaking so thought making a more detailed post in the right environment could help me out.

 

[Alec_t]

Could you use a larger speaker plus a funnel-shaped adapter tapering to 35mm diam? That would give you a bigger choice, higher power rating and greater bandwidth.

 

[BobK]

Can you explain a little more about the configuration? Does the speaker mount outside the box over the 35mm hole, or is the speaker inserted into the box through the 35mm hole, and hence must be smaller than that in diameter?

Are you aware that a speaker with the back open has very limited bass response? You must enclose the speaker such that sound cannot get out from the back, or, at lower frequencies, the front and back waves cancel each other.

Bob

 

[JoshuaGates]

Hey have considered a funnel-shaped adapter with the larger conventional speaker but am more looking toward having the system embedded in the probe. So yes the speaker will be inserted into the box through the 35mm hole so diameter must be less than that. I was not aware of that characteristic so if I were to make this probe to insert into the box I would have to enclose the speaker in a casing of some sort for insertion correct?

Have looked into my options a bit and have selected this speaker with this amplifier (links below). I chose the amplifier due to its size and being pre-built and providing up to 1.4W and the speaker due to its 28mm diameter and 1.5W rated power. Are these valid thoughts behind the selection of the above two components?

https://www.sparkfun.com/products/11044

http://nz.rs-online.com/web/p/miniature-speakers/7564618/

Would the incoming signal from the laptop microphone port just be sent using an audio jack with open connections to attach to the amplifier board? Or could I achieve the same thing with an off the shelf microphone, cut off the audio jack connection and then attach that to the amplifier board? I'd want to make it press to talk so I could either do that via software or a button depending on the option I choose above correct?

Sorry for all these questions but am rather new to all these concepts and if the questions don't make sense or you need more information just let me know as I realise it makes sense to me when I ask but I might not convey that all too well. Also sorry if I am not allowed to post those links but just wanted to give reference as to what I was describing.

Thanks