Cab Power Handling (solid state vs. tube power)

Discussion in 'Amps and Cabs [BG]' started by bishop55, Jul 27, 2009.

  1. Hello fellow thumpers,

    I am fortunate to have the Fender Bassman 300 pro, all-tube 300 watts. I run it through an Ampeg SVT 8X10 HLF, rated at an astounding 1600 watts, 3000 peak (!) It sounds great, but even with all that power the head can drive the speakers just at 3 or so on the master volume, not distorting, just clearly pushing them.Thing is, I would like to try 2x15's with the head.

    I have always heard (as in been told and actually heard with my own ears) that tube power is stronger than solid state. But how does this relate to the manufacturer ratings of cabinet power handling? I have found that many 2x15's are rated at around half what my 8x10 can handle, so they are like 800 watts, 1600 peak. Does this mean 800 "solid state watts" or what?

    Thanks, I'll hang up and listen.
  2. SpankyPants

    SpankyPants That's Mr. SpankyPants to you.

    Aug 24, 2006
    Brooklyn, NY
    *punches self*
  3. SpankyPants

    SpankyPants That's Mr. SpankyPants to you.

    Aug 24, 2006
    Brooklyn, NY
    Alright, just being dramatic.

    The long and short of it is that a watt is a watt, regardless of the medium used to produce it. The natural progression of tube amps into compression and overdrive as they increase in volume gives the illusion that they can push more power before distorting. In reality, the distortion is just more pleasant. Distortion is defined as any change to the signal that was pumped into the power amp, so the natural tube nuances (even when clean) still count as "tube distortion." Solid state distortion is just a lot more noticeable and crappy (generally).

    Most cabs, on the other hand, will generally blow up if they're actually driven with their rated power wattage.
  4. MIJ-VI

    MIJ-VI Inactive Supporting Member

    Jan 12, 2009
    To suppliment what SpankyPants said...

    Due to tube compression, tube amps sound louder than transistor amps of equal wattage, the same way the compressed audio in TV commercials sounds louder than the sound track of a broadcast movie, even though the audio in both cases is peaking to 0 dB.

    When it comes to cabs which are to be used with all-tube heads for over-driven rock bass, I became a big fan of overkill power handling after frying a few speakers.

    BTW bishop55. An 8x10 can handle more power than a 2x15 because it has four times as many voice-coils to dissipate heat.
  5. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    If you're planning to stay clean with it, a 215 cab that can "handle" 800w should be fine (power handling is one of the most bogus specs out there). It would also probably take some distortion, maybe not turned up all the way, but a good enough amount for most. Just remember an SVT can put out over twice as much wattage as its RMS wattage on peaks. Won't be much of an issue if you play clean, though.
  6. When a speaker starts to fart, you've reached its power handling limit. No way to know where that is until you try a given cab with a given head as the manufacturers don't list mechanical power handling.

    Thermally, you have 300w of heat generating power going into a cab capable of displacing 800w worth of heat from a continuous signal. Even distorting the tube amp you would have to have peaks in output over 1600w to overheat the voice coils, and you will hit mechanical limits before this. The thermal limit in this situation (2x15 vs 8x10) is a non issue.
  7. Thanks y'all.
  8. experimental bassist

    experimental bassist

    Mar 15, 2009

    Don't y'all just love our Virginia accents? :smug:

    (Props and respect to Beefkake!)

    Peace. :bassist:
  9. SpankyPants

    SpankyPants That's Mr. SpankyPants to you.

    Aug 24, 2006
    Brooklyn, NY
    Cher, I'm frum sout louisiana. Our accent so flat y'all. compro mais la?
  10. greenboy


    Dec 18, 2000
    remote mountain cabin Montana
    greenboy designs: fEARful, bassic, dually, crazy88 etc
  11. That Fender 300PRO is a POWERFUL beast of an amp... I think I could EASILY 've blown UP my old SVT410HLF EASILY with it... SUCH a loud amp!!
  12. RobbieNuke


    Jan 22, 2008
    Solid state or tube, it is the same amount of power regardless. ​

    I've been hearing a lot of younger musicians lately make statements about the power rating of amps (i.e. 100 watt tube amp is more powerful than 100 watt SS amp). Back in the late 60's/early70's, some of the older musicians in my area were saying that the British (or European) amps were more powerful than they're USA distributed versions... in particular reference to the Vox AC-30. I speculate that they were somehow equating line voltages instead of watts!
  13. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Bunch of what makes valve heads louder is the more limited bandwidth, the output transformer filters out lows which keeps cabs even happier.
  14. BassmanPaul

    BassmanPaul Inactive

    And this thread is three years old. :(
  15. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    You ain't kidding bassman paul, after all its quite a long time since Victor Wooton looked like this.:D
  16. oinkbanana


    Oct 20, 2011
    what is this cab? I'm very curious.