crazy space constrained speaker

[Thinktank]

I am making a prop weapon, and while I don't necessarily want it to be screaming loud, I would still like to produce good quality sound. I want to try to avoid the small speaker sound... while using a small speaker...

the microprocessor i am using has a class D amplifier designed to run a 8ohm 1W speaker, or a 4ohm 3W speaker. as far as space is concerned, I want to stay within a 1 1/2" diameter, which looks like it will generally be in the 40mm driver range.

in essence, I am making a toy sword and the only real place i think i have left to work with is the pommel.

my understanding of acoustics is incredibly limited, but the main thing i know is I cant just not put anything around the backside of the speaker, the question is how much space i must make at a minimum, whether i should put anything inside of that space, and whether i should create a port anywhere.

I'd love to explore other ideas, but i dont have much space above the handle for anything but a transducer? I doubt i really want to get into turning a polycarbonate sheet into a speaker.

 

[Lavane]

Have you looked at Partsexpress? They have all kinds of drivers from very small to huge.
https://www.parts-express.com/speak...s-subwoofers-midranges-tweeters/mini-speakers

 

[Lavane]

One example
https://www.parts-express.com/Dayton-Audio-CE32A-8-1-1-4-Mini-Speaker-8-Ohm-285-101

 

[Thinktank]

One example
https://www.parts-express.com/Dayton-Audio-CE32A-8-1-1-4-Mini-Speaker-8-Ohm-285-101

Thanks! refreshing to see a small speaker with some actual characteristics and specifications listed. ill see about plugging in those stats to one of those box volume requirement calculators. i think its a function of displacement?

 

[Lavane]

Yes.

 

[roger2]

...

my understanding of acoustics is incredibly limited, but the main thing i know is I cant just not put anything around the backside of the speaker, the question is how much space i must make at a minimum, whether i should put anything inside of that space, and whether i should create a port anywhere.

....

No...you can have a speaker without anything around its backside....i.e. an enclosure. Lack of enclosure will significantly affect bass output. Midrange and treble portions of the frequency spectrum will not be affected in the same way. Speaker design parameters involving enclosure size and venting have to do with tuning a (specific) driver to maximize bass its performance.

I don't know what your design goals are...or even what it is that you are creating to be honest. But if bass output is not important, then you may have more options than you are thinking currently.

Welcome to AK

 

[Thinktank]

No...you can have a speaker without anything around its backside....i.e. an enclosure. Lack of enclosure will significantly affect bass output. Midrange and treble portions of the frequency spectrum will not be affected in the same way. Speaker design parameters involving enclosure size and venting have to do with tuning a (specific) driver to maximize bass its performance.

I don't know what your design goals are...or even what it is that you are creating to be honest. But if bass output is not important, then you may have more options than you are thinking currently.

Welcome to AK

interesting. I dont know that i can put my goals for base performance in any quantifiable terms. the project is a toy sword, like a lightsaber, but with less stringent space restrictions.

one of the things i want to be able to do is play mp3 files with minimal distortion. sound accuracy means more to me than volume. after that I would like to look into minimizing the directionality of the sound. the open ended design i tried first sounded weird as you switched from getting the sound primarily from the front or the back, or at least i think that is what was happening. I think it would be best to make sure the sound is as ideal of a point source as possible, but I dont know that i would want to do anything much more involved than a simple deflector (maybe a cone pointed at the speaker?) if anything.

 

[elnaldo]

Check also laptop computer speakers. They are usually very small and some sound pretty decent for the size.