Witch one will be loudest?

Discussion in 'Amps and Cabs [BG]' started by jock, Jul 17, 2001.

  1. jock


    Jun 7, 2000
    Stockholm, Sweden
    Two 15" cabs with SPL: 94db 1w@1 mtr OR one cab with 15"+6" with SPL: 103db 1w@1 mtr?
    Any Ideas? I read somewhere that when you stack two speakers opposed to putting them on each side of the stage you gain 3dB. Is that something to consider?
  2. Not that I'm much damn help, but I listen to those that I'm comparing.

    My ears never let me down. Spec's have.
  3. I ignore SPL ratings.

    I pay attention to the tone.
  4. Aaron


    Jun 2, 2001
    Seattle, WA
    parle englais?!! Hey man, specs don't mean a thing, just let your ears guide the way!!!
  5. MikeyD

    MikeyD Guest

    Sep 9, 2000
    Not to refute what the others say (I respect their opinions, and what you hear should definitely weigh heavily in your decision) - sometimes it's hard to really do a fair audition on cabinets. Some stores don't have both models you're trying to compare. Even if they do, they might be far from each other and subject to the acoustic conditions in which they are placed. Ears can be fooled. Easily! One cabinet could be sitting in a quiet corner made of cinder block walls while the other is sitting in the middle of the noisy floor surrounded by 20 other cabinets, 3 of which are being auditioned by others at the same time. This can drastically affect what you hear.

    Anyway - to the technical question. If you stack those two 94 dB cabinets, their loudness at frequencies below 1/4 wavelength (as bgavin has been stating elsewhere) - which is *roughly* 100 Hz. for typical cabinet sizes (what did I say? this is ROUGH!! okay?), then the effective sensitivity goes up by up to 3 dB. I don't think it will go up much above that frequency. However, if the two cabinets mean half the impedance of the other one, then they will receive more power from the amp as well and sound louder. But even at double the power (+3 dB) and mutual coupling at low frequencies (+ 3 dB), the result would be 94+3+3 = 100 dB. This is still shy of the 103 dB figure of the other cabinet. Seems like the 103 dB cab would be the winner.

    However, I don't know how the manufacturers actually measured their cabinets' sensitivities. Did they do it at the same frequency? Does the presence of the 6" driver help one cabinet achieve its higher figure? Did they both ensure each cabinet received the identical wattage - or did one of them use 2.83 volts instead? These things can throw the whole thing off, which is why you must also try to audition them as well. My guess would be that the 103 dB cabinet would be a bit louder than the pair of 94 dB cabinets.

    - Mike