I've had many audio interfaces over the years from Audient, Focusrite, Apogee (an old Rosetta 200 with X-firewire card), Motu etc...I have to say this Apogee Boom has truly excellent sound quality for it's price wow. It's DAC is SO good it replaced my Cambridge Audio DAC Magic 100 USB DAC. Now the downside, it isn't plug 'n' play so it won't work unless you have a Mac computer or Windows computer with the Apogee Control 2 software installed or a latest generation iPad with the Control app installed on it.
I was gutted it wouldn't work on my Android tablet and I think Apogee need to make an app to be able to use it because millions of people have Android phones and tablets so Apogee are potentially missing out on even better sales from customers who don't want to have to buy an iPad, Mac or Windows pc but do want to use the Boom.
But anyway, vocals are very, very clean and clear, the bottom low frequency end is clean too the amount of detail the Boom reveals is absolutely great. It's well worth it's cost.