Speaker Quality?

Headphones work really well with laptops.

 

The MBP speakers aren't great, but you can use headphones or external speakers.

 

While headphones or external speakers will obviously get much better sound, the built in speakers really are pretty good, especially when compared to allot of PCs, or even older macs. The speakers in my 15" uMBP are much louder & bassier than the ones in my 15" Pre-Unibody MBP. The speakers in the 13" are almost exactly the same sound as the ones in the 15", only difference is the sound comes from under the keyboard as against the grilles in the 15".

 

That will unfortunately make a world of difference, since the keyboard/casing isn't by any means acoustically transparent. It will cut or muffle the mids and highs quite a bit, which will make for poor sound quality for especially for audiobooks.

 

The 13" will be more than enough for audiobooks I'd imagine. A cheap set of headphones is money well spent compared to going to the 15" just for dedicated speaker grilles.

 

i own both a unibody macbook pro 15" and the black macbook.

there really isn't a difference in the quality of sound. they are both mediocre.

external speakers on the unibody seems a little better

 

They are fairly loud compared to other laptops I've tried. I've seldom had the problem where you just can't turn the volume up high enough.

 

Using the MBP 13", 15" and 17" along with iMac and MacBook Air, I find the 17" have the best sound quality. The iMac has the loudest.

 

It really doesn't. The sound is exactly the same. If anything, the grilles would let out less sound as the holes are much smaller than gaps in the keyboard. I'm big on audiobooks too & you can hear every word clearly from the other side of the room.

 

Another option...

Here is another interesting option...

You could get a really tiny, high quality Bluetooth headset, and select it in OSX as your audio output, it's not ideal for listening to music, but for books it would work quite well, no cables, no fuss!