The slam you get from the ear buds is because being in the ear canal they only need to move a very tiny volume of air. Much less than 1 cc I would think. The speakers you're using have to fill a volume millions of times greater.
Those ear buds by the way are crap. You're right, they boost the bass response. Ear buds that sit in the ear without making a tight seal around the ear canal are losing bass out the cracks, so to speak. Plus being free they are pure crap. So they boost the bass to warm up the sound hiding the fact they are awful in pleasing warm exaggerated bass.
What you want are some good IECs, Inner Ear Canal phones. The Shure SE-535 is a good solid bet and will blow away any ear bud with much deeper, flatter and more accurate bass, beautiful midrange, excellent grain free extension and incredibly more lifelike dynamics.
Those ear buds by the way are crap. You're right, they boost the bass response. Ear buds that sit in the ear without making a tight seal around the ear canal are losing bass out the cracks, so to speak. Plus being free they are pure crap. So they boost the bass to warm up the sound hiding the fact they are awful in pleasing warm exaggerated bass.
What you want are some good IECs, Inner Ear Canal phones. The Shure SE-535 is a good solid bet and will blow away any ear bud with much deeper, flatter and more accurate bass, beautiful midrange, excellent grain free extension and incredibly more lifelike dynamics.