Uncovering the Physics Behind X Mini Speakers

[paulfr]

Does anyone know what physics is behind the incredible sound that comes from the X Mini speakers ??

https://www.amazon.com/dp/B001UEBN42/?tag=pfamazon01-20

How are they able to produce such volume from so small a package [the size is midway between the size of a tennis ball and a golf ball] ??
They actually replace computer speakers that are 20x their size.
It is amazing !

And it does this while retaining very reasonable fidelity when playing music.

When was this technique or technology discovered ?

 

[Mech_Engineer]

Loud doesn't mean the have good noise fidelity. They're just little speakers, and they certainly don't replace larger speakers when you take into account things like bass response.

 

[Greg Bernhardt]

edited title, bump

 

[Studiot]

This is a duplicate posting that was already answered

https://www.physicsforums.com/showthread.php?t=508461

 

[berkeman]

(Two threads merged)

 

[paulfr]

Loud doesn't mean the have good noise fidelity. They're just little speakers, and they certainly don't replace larger speakers when you take into account things like bass response.

I never said they replace them
And, I said they sound nearly as good as one 20x their size
Of course a larger speaker will most likely have better fidelity.

Have you heard one personally ?
If not, I predict that unless you work for Bose or Lansing, you will be impressed

I am a teacher and my school does not have speakers in the classroom. So I have to lug a box of computer speakers to each class [in Asia, teachers go to the students room, not students to the teacher's room]. These speakers save me a cumbersome task up and down stairs many times a day carrying that box along with other materials. It is exactly what I need.Does anyone know the physics behind this remarkable achievement ??

Also I posted to 2 sub forums because many people who read General Engineering do not read Electrical Engineering and I felt a wider audience might more likely get me a good answer to my questions. I wanted to be sure some ME's read my post. Speaker technology is as much Mechanical and it is Electrical. In fact, I almost made a third post to the ME sub forum. I do not see any harm in having 2 threads. Electrons and memory are quite inexpensive.

Thanks

 

[berkeman]

Also I posted to 2 sub forums because many people who read General Engineering do not read Electrical Engineering and I felt a wider audience might more likely get me an answer to my questions. I do not see any harm in having 2 threads. Electrons and memory are quite inexpensive.

Thanks

Multiple posting is against the PF rules (see the Rules link at the top of the page). But you know that now...

 

[uart]

I haven't heard them paul, but are they passive or are they powered?

It is possible to have some clever inbuilt equalization in a powered speaker that compensates very well for what would otherwise be the poor frequency response due to the small size.

 

[berkeman]

Here is a video review by CNET:

http://reviews.cnet.com/mp3-player-accessories/x-mini-max-ii/4505-6519_7-33888611.html

They appear to give it pretty high marks. I don't have time to watch the video now, but it may talk some about how the sound is being modified/produced...

 

[paulfr]

I haven't heard them paul, but are they passive or are they powered?

It is possible to have some clever inbuilt equalization in a powered speaker that compensates very well for what would otherwise be the poor frequency response due to the small size.

Good observation, thanks

Yes there is a battery in the little thing and it can be recharged via the USB port of the computer.
It advertises 11 hours of operation on a charge but I doubt that is at full power.

Active equalization does explain the good fidelity

I tried them today in class using 2 wired in series [they advertise using as many as 6 at a time]
It worked well in a classroom of 30 ft x 30 ft but was a bit weak when the kids were talking too much.
JFYI I do recommend them.

Cheers

 

[DragonPetter]

Does it have any chambers built in it? Hard to tell from the picture, but there could be some type of acoustic chamber inside it that helps the sound.

 

[Mech_Engineer]

I never said they replace them

Please re-read your original post:

How are they able to produce such volume from so small a package ... They actually replace computer speakers that are 20x their size.

Have you heard one personally ?
If not, I predict that unless you work for Bose or Lansing, you will be impressed

Yes, my brother got a pair of these for a door prize. They're little battery speakers that have an exapndable resonating cavity and can be chained. I'm not easily impressed by speakers, and these are just little battery-powered iPod speakers. They're not technologically different than the hundreds of other varieties available online.

I am a teacher and my school does not have speakers in the classroom. So I have to lug a box of computer speakers to each class [in Asia, teachers go to the students room, not students to the teacher's room]. These speakers save me a cumbersome task up and down stairs many times a day carrying that box along with other materials. It is exactly what I need.

Good, sounds like they're a good match for you.

Does anyone know the physics behind this remarkable achievement ??

There's nothing special about them, they're just speakers like any other. They run off of batteries so they have a small built-in amplifier, and they have an expandable resonating cavity for slightly better mid-tones.

Also I posted to 2 sub forums because many people who read General Engineering do not read Electrical Engineering and I felt a wider audience might more likely get me a good answer to my questions. I wanted to be sure some ME's read my post. Speaker technology is as much Mechanical and it is Electrical. In fact, I almost made a third post to the ME sub forum. I do not see any harm in having 2 threads. Electrons and memory are quite inexpensive.

Multi-posting is against the forum posting guidelines because we don't want to have a bunch of duplicate threads with different conversations floating around. Keep it to one thread in the future.

 

[Studiot]

What is an expandable resonating cavity please?

 

[AlephZero]

What is an expandable resonating cavity please?

Apparently it's just collapsible (telescopic?) box, to reduce the size when you want to carry it around - but the reviewer here says it sounds no different whether it's collapsed or expanded!
http://www.macworld.com/article/140117/2009/05/mini_ipod_speakers.html

 

[kppanic]

I never said they replace them
And, I said they sound nearly as good as one 20x their size
Of course a larger speaker will most likely have better fidelity.

Have you heard one personally ?
If not, I predict that unless you work for Bose or Lansing, you will be impressed

I bought one of these, a black one, for my girlfriend's laptop.

At the end of the day, it does the job, and it is definitely much better than internal laptop speakers. Small size is a convinience as well.

However, regarding the sound quality, it is just mediocre. I didn't buy the speaker for quality, i bought it because my girlfriend thought it was cute and she'd rather have this one than a square, blockly looking thing.

If you wanted to know the physics behind speakers, basic rule of thumb is: SIZE.

The bigger a speaker, the better sound. I am not just talking about the "loudness". There needs to be enough space in there for sound frequency reproduction and resonance to occur. Small speakers just cannot do that better than larger speakers.

Now, you speak of Bose speakers. They are in fact, not very good at sound reproduction. They are absolutely great at what they do: they are small, aesthetically pleasing and comes with a "brand" recognition. However Bose speakers are never considered "audiophile" grade. Bose do, however, make some nice speakers at an ultra- high fidelity level (for stages, concerts, etc) and although I've never had direct experience with Bose equipment at that level, I was told that they are competitive.

I am a teacher and my school does not have speakers in the classroom. So I have to lug a box of computer speakers to each class [in Asia, teachers go to the students room, not students to the teacher's room]. These speakers save me a cumbersome task up and down stairs many times a day carrying that box along with other materials. It is exactly what I need.

These speakers are then suitable for your needs.

Does anyone know the physics behind this remarkable achievement ??

There is nothing strikingly remarkable about these X Minis nor a milestone achievement has been achieved.

 

[DoggerDan]

Loud doesn't mean the have good noise fidelity. They're just little speakers, and they certainly don't replace larger speakers when you take into account things like bass response.

The latest in earbuds tells me my chest is being thumped by a 12" woofer, even though it's just the earbuds fooling my brain.