Is this a tuba or a synth?
 

Hi! What do you think this instrument is? Sounded like a tuba to me at first but then I tried to browse some tuba samples and I'm having doubts now. I'd like to use a similar sound in one of my songs. Thank you.
It starts at 0:06. Just the two low notes repeating.

Sounds all synth to me - except the singer (maybe :)).
Check out clarinet synths.

If it was a tuba, that player would need to be employing circular breathing... ;)

I'd say a tuba (or trombone?) sample on a synth.

Thank you both very much!!