Watts vs Decibels is it worth it?

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

  1. Linnin


    Jul 19, 2012
    Linningrad, Earth
    BadExample likes this.
  2. Shpigel


    Sep 19, 2016
    More 7db = about x2.3 loudness (more 6db=x2, more 12db=x4, more 18db=x8, etc ).
    Last edited: Nov 24, 2016
  3. There's no shortage of bad information on the forums this week. The Tim the Toolman Taylor approach (more power! urhh, urhh, urhh) fails far more often than it succeeds.
    Is each Carvin 4x10 cab 4, 8 or 16 ohms?
    Is each cab plugged directly into one of the speaker output jacks on the amp or are they daisy chained?
    Do you stack the cabs vertically, place them side-by-side or put them on opposite sides of the stage?

    I don't know where you got those numbers but they are incorrect and they'd be meaningless even if they were correct.

    I'll grant that a 150W bass rig will rarely keep up with a 100W guitar rig, even with the guitar playing at reasonable volume. OTOH if the two cabs are 8 ohms apiece, with both plugged into the amp, the BH220 will put out 220W. 220W into eight tens ought to rumble the walls at any gig shy of stadium rock. The eight tens are the real tool here and it seems you just need to figure out the settings of your bass and amp to work them properly and pop out in the mix. BTW, is there any reason you're NOT using the DI?
    hrodbert696 and pudgychef like this.
  4. ShadowImage

    ShadowImage Guest

    Jan 12, 2016
    I would say the OP is due for a new bass head. The Crate BH 220 is outdated and underpowered at only 220w at 4ohm on a 35lb head :oops: For about $150 you could get a cheap class-D amp that outputs 350w at 4ohm and weighs only 8lbs.
  5. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    There are some interesting replys here in thread...

    While the example is in dBw, the math is ok relative to power.

    Given the power levels involved, the speakers are almost certainly currently being driven well within their power limitations with plenty of reserve available. This means that for each additional dB of added electrical power adderd, there will be close to an additional dB of additional SPL ( operating within the linear region)

    So IMO, adding 6dB of power would result in a useful increase in volume.

    Other things that affect the impression of volume are the voicing of the amp, and the inclusion of an effective high pass filter above say 35-40Hz.

    This means that an amp capable of delivering ~800 watts (RMS) into 4 ohms would be a good approach. Beyond 800 watts, the assumption of linearity may not apply.
    HolmeBass and One Drop like this.
  6. ficelles


    Feb 28, 2010
    Devon, England
    Just in case anyone still thinks this refers to the sound pressure level you get from a bass rig, maybe I should mention that 60dB is normal speech, like not even shouting. My iPhone can push out more than 60dB SPL.
  7. I've had 2 of the crate bx220's I ran mine with a 4ohm trace 210 and 8ohm crate 115.

    I was able to get more than enuf volume out of it. My band consisted of a two guitars and a hard hiting drummer. I'm not sure how much stress I put on the head running a 4&8 ohm cabs with it but it has been one of the most reliable heads I've ever owned.
  8. StayLow


    Mar 14, 2008
    Too many unknowns and red flags.

    1. Crate ... not exactly quality gear, and unlikely the claimed output wattage is accurate.
    2. Two 4x10 cabs run at 8 Ohms .. how? I don't think Carvin makes 16 Ohm cabs. Unless they're guitar cabs maybe?
    3. Guitarist's 100w head, mic'd?!? Is that 100 Crate "watts" too? What cabs is he using, two 4x12 or a 1x10 or...?
    4. EQ'ing of bass and guitars. What genre are you performing?
    5. Variables such as room acoustics. Is the stage a bass trap? Is the venue filled with very loud people? Once you start pushing a typical 300+ capacity room, unless it's cozy you probably want to be in the PA to get any kind of balance throughout the room, especially if guitars are in the PA, but it really depends on the actual size & shape of the room, the genre, and how well you're projecting (EQ, if there's a wall behind your rig, etc.).


    1. If the gear is legit, two 4x10 cabs will be extremely loud even with 200w.
    2. You'll get much more volume by adding speakers than amp in most reasonable circumstances, but if you already have two quality 4x10 *bass* cabs that's far more than enough for any gig unless you're trying to fill huge rooms without PA which makes no sense.
    3. A quality amp, far smaller and lighter, will be more than enough with *one* of those cabs in virtually any situation.
    4. Two of my bands are extremely loud. One features two guitarists with a lot of low end in the "brown" sound, down-tuned, with 100w tube heads each luckily "only" running into one 2x12 cab each, and with a 4x10 and a 500w MarkBass I can juuuust get by in rehearsals in a smallish room or live with help from a professional venue PA. In another loud band I have no problem with "only" a 300w amp and a large 2x15 cab despite both guitarists using 100w Marshalls into two 4x12 cabs each. I use a very mid-forward sound in that band and a bass with a lot of mid punch, and just because they have massive rigs doesn't mean they'll crank them (usually).
    Last edited: Nov 24, 2016
    Munjibunga and monsterthompson like this.
  9. shawshank72


    Mar 22, 2009
    I love burgers!
    Cirk and Linnin like this.
  10. monsterthompson

    monsterthompson The Eighth Note Wonder Of The World Supporting Member

    Nov 25, 2008
    ...though, in the OP's case, he's got two 410 cabs, so the issue here could be solved with more watts. Either that, or the cabs are terribly inefficient, and better ones would help out.

    I'm assuming each 410 is 8 ohms, so the amp sees 4 ohms, and the head puts out 220w at 4ohms. Each cab is getting 110w. I'd certainly consider snagging a better head that can push those cabs closer to their rating.
  11. Cirk


    Jan 16, 2011
    Panama City, Florida
    Just an idea... SansAmp RPM and a Carvin DCML 1000 run at 4 ohms bridged. 500 watts RMS into each cab. Your guitar player will beg for mercy.
    If you feel uncomfortable running the Carvin at 4 ohms bridged, you can run both channels at 325 RMS into 8 ohms each.
  12. AaronVonRock


    Feb 22, 2013
    Not trying to derail the thread, but I'm interested in your 210 and 112 set-up. What are you using exactly?

    I usually use a Hartke Hydrive 410 with an Orange Terror Bass 500. I have a Hartke Hydrive 112 that is not getting any use at the moment. After reading your post, you got me thinking of getting a Hartke Hydrive 210 to go with the 112. What is your experience with this setup vs using a 410 only? Or two 112s? Thanks.
  13. Cirk


    Jan 16, 2011
    Panama City, Florida
    If both cabs are the same impedance, the power would be equally split between them. Your 12 would be working 4 times harder than your 4x10. If it was starting to blow, you wouldn't hear it until it was too late. See the many threads on using a 4x10 with a 1x15.
  14. AaronVonRock


    Feb 22, 2013
    I'm not talking about using a 410 and a 112. I'm talking about using a 210 and a 112. Both cabs being Hartke Hydrive. The 112 is 300 watts with a 4/8 ohm switch, and the 210 is 500 watts at 8 ohm.
    Last edited: Nov 24, 2016
  15. ficelles


    Feb 28, 2010
    Devon, England
    If the cabs are the same impedance and the 112 has similar power rating to the 210 and the total rating is adequate for the amp, there is absolutely no issue as far as power split between the two enclosures is concerned. The number of speakers in a cab is irrelevant, it's the total power handling.

    Whether it sounds good or not of course is up to you!
    AaronVonRock likes this.
  16. lamarjones

    lamarjones Supporting Member

    Aug 27, 2002
    Raleigh, NC
    This, the difference pointed out in those values, even though the translations for different amps are questionable, is much more different than what you are thinking.
  17. SanDiegoHarry

    SanDiegoHarry Inactive Supporting Member

    Aug 11, 2008
    San Diego, CA
    Tecamp Puma 500
    Bergantino CN112 + Berg CN210

    Stunningly full / loud. I credit the cabs more than the head - they are simply huge sounding.
    I've also gigged a similar setup with two CN112s and had zero issue with volume - even out doors (I replaced one of the CN112s with the 2x10 to get more beefy bottom)
  18. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    For that size venue I'd go with an 800-watt head and at least one good 410 if you don't have PA support.
  19. Moordoom


    Feb 8, 2016
  20. StayLow


    Mar 14, 2008
    1. That is by far the most common speaker output setup on bass amps.
    2. Two 8 Ohm cabs connected one each into those two speaker outputs will results in a total load of 4 Ohms, as per your amp's manual.
    3. There's something very wrong somewhere if you're having trouble being heard with two 4x10 cabs. My guess is there's some form of user error given the posts so far (EQ'ing perhaps) or gear issue (Crate). Possibly the cabs are out of phase? Were they purchased new or used, and if used from the same source?

    Gotta give more info. in order for people to help you. Best bet is a live video of the band, or someone local who actually knows their stuff helping you out. Experienced gigging bassists can give lessons in playing bass *and* in setting up your live sound, so even paying someone to help out can be well worth it.
    Last edited: Nov 24, 2016
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    Jun 13, 2021

Share This Page