I am a 60 year old bassplayer. I started playing in bands in the mid sixties and continued into the 70s playing in the later years 4-6 nights a week every week around CT-New York .In 68' heard the Jimmy Hendrix Experience play out in the middle of a local football field and even though I was in the bleachers far away - I could feel my chest vibrate from the 6 Sunn 200s bass amps that Noel Redding was using. They contained 2 JBL 1 5 inch speakers each in a unique enclosure. I ran out and bought a Sunn 200s for $685 (list around $850) and my whole world changed. When I played small to medium clubs in New York people said that they could feel the bass in their chest even at the bar in the other room. Some club owners told me that they noticed the front windows of their club shaking with my bass. Unfortunately I gave the Sunn to a friend when I left Connecticut. I now miss it like a lost family member. I recently bought into the current idea of a good 4 10 enclosure with high end speakers and a powerful amp with a tube in the preamp. Not the same. Sounds great but the 4 10 enclosure does not shake your chest. I know that the popular focus now is on hearing the bass leads and a more treble register but I honestly think many bass players now do not realize what it was like to shake the audience's bones . The Sunn had a bass boast button and when pushed down( which for me was always ) it shook the walls without being too loud. I never ran the amp over 4.5 on the volume. Tubes and a good enclosure with JBL 15s was the key. The JBL 15s are unique. They were like a giant piston pushing air at the audience in very powerful way. The 10 inch speaker thing started to became popular in the early 70s with Traynor amps but I never heard them move air and push the chest vibration like the JBL 15s in the Sunn Ampeg in those days were mostly the type that made good studio amps but I used them and they did not project well in a live situation. Accoustic had a weird speaker that was turning backwards to the front and was loud but again no powerful vibes. The Sunn amps were the amps of the day and were used by Noel Redding ( Hendrix Experience ), John Enwistle in the Who, and at times by Jack Cassady of the Jefferson Airplane. The 200s was only about 65 watts but the 2 JBLs made the difference. I hate to see that JBL stopped making the D140 15 inch just recently due to lack of demand. You younger bass players really do not know what you are missing.