Originally Posted by caslca
Being one of the people who did the HW mod, I'd say both. The HW is definitely not properly made, most notably the speaker hosing is sealed which doesn't allow the speaker to move air efficiently and so makes for a very lousy sound. There also have been some success in SW which makes me think that with 5min spent to do the HW mod and decent SW update the phone can finally become borderline usable as far as speaker goes.
Vibration is another issue...
there is a reason speakers have a sealed back. it's to keep the sound on th erear of the speaker from cancelling the sound on the front. dipole speakers don't have a sealed back and they drop a very regular decibel every octave below the wavelength of the baffle. there isn't much room for a large baffle in a phone so the back is sealed instead to try to preserve what little bass a small speaker can create. but the bass the speaker can create is soo little you may not notice the loss and instead notice some gain from increasing speaker excursion and effectively having double the cone area.
there are also ported/bass reflex boxes that phase shift the rear sound wave through a resonant chamber and a port to extend bass by putting the rear wave in phase with the front for a small frequency window.
there are other designs. but not much that will fit in a phone. i wouldn't say the design of the phone is faulty, just ineffective on such a small scale. maybe a trasmission line design where there was a channel that snaked around all the free space in the phone would be better. a rear loaded horn would be louder but takes up a lot of space.
as far as software, well there is only so much voltage that the internal amp can drive the speaker with. they have to find a gain ratio where there is enough headroom at full volume for most content to play without clipping. music is very dynamic and the louder something is the more extra energy you need to create an equivalent apparent change in loudness. you can raise the gain on almost any well designed system and not experience clipping on 90% + of a song but there may be a section of a particular song where you lose headroom and drive it into clipping. they probably went on the safe side with the hardware gain to preserve the quality of the music. but by all means if you prefer more loudness use a software mod.
there are some things that you could do, like software compression where the gain drops on the parts that exceed the max loudness. but it can make the music sound less lively. or you can just let it clip and maybe eventually damage the amp and/or speaker but that's probably not even a problem on such a small scale.