Originally Posted by countrybassman
I know this subject has been threaded before, but here is my issue. I have recently purchased a Reeves 225 tube amp and gigged out with it this weekend. I ran it thru my current speaker cabs, (Eden 212 and Eden 210), both 8ohms into amp set at 4 ohm load. This amp is top of the line amp as we all know, but there is so much boomy bottom coming out of my current speakers. I tried different settings but could not get that tight blooming tube sound that I know this amp can produce. When I did some slap style playing I thought I was going to blow my speakers. This is my first tube amp as I am used to solid state power amps. Reading some posts on TB forums got me thinking my ported speaker cabs might not be the best choice for my new amp, as the sealed cabs might be a better choice (ex. Bergantino HD112 or HD212) to get the best sound out of this amp. As for the slap style playing, I know tube amps aren't the best choice for that, but my band does do some songs that require it. Any suggestions would be helpful........thanks TBers
May be it is not boomy but rather a washy and undifferentiated sounding at the lows which causes the problem.
KT88 tubes provide a little bit more bass bottom then 6550.
Whereas 6550 tubes do a little bit more focus at the midrange band especially at higher levels at the edge of max. output power.
Regarding to the Ohm matching, sealed cabs tend to fit better to tube amps because Zmax at cabs system resonance is sweet-tempered. Whereas a lot of vented cabs are pushing a significant high Zmax at system resonance.
May be that a "nominal" ohm mismatching can help to moderate such a problem.
Sealed cabs provide a better step response at the lows then vented. So vented cabs in general demand an improved controlling by the amplifier output stage which some tube amps can't provide in adequate way.
Tube amps like the SVT come with a sufficient strongly closed-loop gain which allows this amp to work well even on some "critical" vented cabs, whereas tube amps like the bassman very probably demand some detailed considerations which cab should be used.
I would contact Revees regarding to the possibilities of:
1) 6550 instead of KT88
2) cab selection (damping and Zmax)
3) Nominal Ohm mismatching