Watts vs Decibels is it worth it?

Discussion in 'Amps and Cabs [BG]' started by Moordoom, Nov 24, 2016.

  1. You may be correct in that definition, but by defining it as you just did it is no longer unqualified.
    The db unqualified, is only used to make a comparison between two values under the same circumstances.
    It's unqualified use does not automatically imply any one unit (SPL for instance) over another.
    agedhorse and wcriley like this.
  2. MVE


    Aug 8, 2010
    Yes, do check the phase.

    I'm surprised it took us so long to mention that.

    Good catch, Staylow.
    Old Garage-Bander likes this.
  3. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    How is this blatantly lying? Most combos have specs that clearly define the load that the power is rated at. If an extension speaker is able to be supported, the power will be delivered, no difference than a head.

    I think you are in general confusing higher quality products with some specific lower quality products?
    Old Garage-Bander likes this.
  4. In my opinion, what some may think is a manufacturer "lying" about the wattage of an amp, is more a case of someone not understanding the specifications they read.

    As you mention an amp's power is rated with the amp operating at a certain, and in most cases, stated in the specs (aka Ohms, aka Impedance) load.
    Power is, in no uncertain terms the current drawn by the load multiplied by the voltage applied to that load, P=IxE.
    It is not practical to measure the power output of an amp while playing music through it. Some types of music are perceived by the human ear as being louder than other types. There is no such thing as measuring perceived loudness. Perceived loudness is what a particular person believes the loudness to be. Since it is basically a personal opinion, it can not be measured. Measured loudness is derived from an SPL meter.

    Consider that grampa's hearing is pretty bad due to years of rock and roll during his youth. Yet if he doesn't like your music, he's gonna yell at you to to turn that thing down, even though your hearing is better and you are sittin' right next to your boom box. He may perceive what he doesn't like as being too loud. What gramps really want's is for you to turn that damn thing off, and get off his lawn. You messing up his finely manicured lawn figures into his perceptions.

    Even the concept of tube watts vs solid state watts requires some qualification to be understood.
    Tubes and transistors both adhere equally to the laws of electricity as explained by Ohm's law.
    P=IxE regardless of amplifier design.
    The difference is in the harmonics of those designs.
    You can have class A amps in either Solid State or tube configurations.
    But the harmonic content is different between the two and the perceived tone and loudness will be different.
    By Ohms law they are putting out the same amount of power. Spectrally though, different harmonics are getting a larger or smaller piece of the power pie (no pun intended) between SS and a tube amps.

    The most accurate way to measure power output is to use a steady state signal, aka a single continuous tone.
    Preferably the tone used is a pure sign wave sans harmonics (as much as it can be as a practical matter).
    A single continuous sine wave will give a different power reading than a single, continuous square wave because they have different duty cycles and different harmonic contents. But no matter, a watt is a watt is a watt, P=IxE.
    Anything beyond a sine wave complicates the power measurements and adds subjective values for the user. One person may perceive the same amp at the same power level, playing the same kind of music to sound different than someone else. That perceived difference might equate to perceived loudness for each individual.
    Last edited: Nov 25, 2016
  5. ShadowImage

    ShadowImage Guest

    Jan 12, 2016
    The error in this statement is where you say "on stage", which is true but the crowd can't hear him. He isn't on the PA (although he should be) and 220 watts is not enough on it's own. It sounds like the clubs they are playing do not like to put him through the mains so he needs a more powerful amp. I would never gig with anything less than 350 watts 4ohms for medium/small venues if there was a chance they weren't putting it through the PA.
  6. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    To clarify my last post, I was explaining what he could do to solve his problem, given that the band has their own 1,000 watt PA but isn't running the bass into it, for whatever reason. The solution is to DI the bass head and let the PA do the work of filling the room.

    This is what I said:
    The PA is for filling the venue for your audience and it's really treated as a separate entity from your stage sound.
    DI your bass amp, and mic the guitar, vocals (obviously) and the kick and snare drum (if you want). Let the 1000 watts from your PA amp do the work.

    Not sure why you aren't currently running the bass through the PA. If you're afraid of blowing your PA speakers with low frequencies, then you should look to upgrade the PA's low frequency capability instead of wasting your time trying to use your bass amp and cab to carry the whole room.

    The OP is being given advice to get a more powerful amp to compete with the guitarist's amp. This is the exact wrong approach. The guitarist is already way too loud for the stage and making the bass louder will only create more problems than it solves. The drummer will have to beat the crap out of his kit to be heard and the vocal monitors will have to be turned up and this inevitably creates feedback.

    The correct solution is to run the bass into the PA that they already have. If their PA is inadequate, then they should spend their resources on upgrading the PA, not the bass head and cabs.

    For what it's worth, I've been playing the last 15 years with a 250 watt solid state head into a 1x15" cab and have never had to turn up past 5. Any gig we've ever done has been with PA support for the bass - if the house doesn't have a PA then we bring our own.
    Cirk likes this.
  7. ficelles


    Feb 28, 2010
    Devon, England
    You caught me :)
  8. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    By your same argument, if the guitar is too loud and turning the bass up is the wrong approach (i.e. bigger amp) then turning the bass up in the PA to make the bass louder will result in exactly the same result...
    wcriley and Old Garage-Bander like this.
  9. Ooh! Ooh! Can I be in a band where they can't hear the bass?
    That would be a great match for my skill level! :laugh:
    tattooSAM, S-Bigbottom and agedhorse like this.
  10. Cirk


    Jan 16, 2011
    Panama City, Florida
    Sounds like me. Don't put me on camera either. I have a face made for radio.
    Old Garage-Bander and agedhorse like this.
  11. BadExample


    Jan 21, 2016
    Ain't got no T-bone (got mashed potatoes). Ain't got no T-bone...
    Cirk likes this.
  12. Cirk


    Jan 16, 2011
    Panama City, Florida
    Po-ta-toes. Boil 'em, mash 'em, stick em in a stew.
    agedhorse likes this.
  13. ubernator


    Oct 30, 2004
    lost angels
    Give it to us raw and wriggling! You keep nasty chips!
    Cirk likes this.
  14. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    The PA is for filling the venue for your audience and it's really treated as a separate entity from your stage sound. DI your bass amp, and mic the guitar, vocals (obviously) and the kick and snare drum (if you want). Let the 1000 watts from your PA amp do the work.

    I'm not making this stuff up. This is accepted practice for performing bands everywhere.

    People. This is not 1965 anymore. We have ways to make shows sound good all the time.
    This is acoustic science. Not voodoo.
  15. ShadowImage

    ShadowImage Guest

    Jan 12, 2016
    Your points are valid, but why should they upgrade their own already adequate PA just to support one more instrument? You said it yourself, most venues should have their own PA and if they don't the stringed instruments should be able to support themselves. They will have to add bass cabinets to their PA, possibly a crossover and overall there are many instances where they wouldn't be bringing their own PA. What about road gigs where the bassist just wants to bring a head and use a backline cab? I don't mean to be rude but his amp head sucks. It was mediocre in 1997 and 20 years later, 35lbs of 220 watts just isn't cutting the mustard even compared to a cheap class D. It's worth $100... I'm sorry but it's time to upgrade.

    It's great that you get by with a small set up, but you shouldn't be giving bad advice to other musician's who may not be able to do the same. Advising a bassist that 220 watts into two 410 cabs is faulty advice period
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    So before things get too deep here, know that I am coming from decades of handling PA for national acts.

    Your argument against balance on the stage is fine but why wouldn't the same argument apply to the guitar? Balance is balance, right?

    So applying acoustic science to the situation, you are correct in your assessment that it's not 1965 anymore. This means the guitarists should have grown up enough to turn down and restore balance to what is coming off of the stage... which I suspect will eliminate a big part of the problem facing the bass rig, the volume was against the guitar rig that can not be won at reasonable stage volumes.

    A typical 1000 watt pa is not an adequate tool for restoring balance against a too loud guitar rig without running out of headroom to get everything else up to that level including the bass. Even if it could, the result would be too loud of a mix for a venue that a 1000 watt PA sound be suited.
  17. They should put that warning on most of their products.:smug:
    WaynerBass likes this.
  18. foolforthecity

    foolforthecity Supporting Member

    Up mine my 1 dB, please (db= double burger).

    Better yet, 1dBc (double with cheese)
    S-Bigbottom, shawshank72 and Cirk like this.
  19. bo0nfavpnatkizblhhx8.jpg
    Bass not loud enough????????
    Problem solved.:thumbsup:
  20. JohnMCA72


    Feb 4, 2009
    They did. I own/have owned several ACC cabinets & all have/had that label.
    agedhorse and tattooSAM like this.
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