In this recording of "Come On In This House" by Junior Wells from 1996, there is a low, rumbling sound and I'm wondering what instrument makes it. It sounds almost like vibes but there are no vibes listed on the album.
Here's a link which should go right to the spot, but if I've fumbled it, it's at about 1:19 and lasts until 1:26 where he sings "I'm begging yooo-ooo".
The sound repeats elsewhere in the song and is a low rumbling sound. You may need headphones. I don't think it's the bass because I hear the bass playing at the same time. I think only acoustic instruments were used on this recording.