Want to change to liteweight speakers in my 15" cabs

Discussion in 'Amps and Cabs [BG]' started by blockinlay, Jul 24, 2009.

  1. blockinlay


    Feb 21, 2009
    Phila Pa
    Jamming through the band's practice amp is easy, as I just bring my bass, but I don't like it. The practice amp is a Fender Rumble 100. Sounds good till I have to turn up to hear over the loud drummer, then it loses the highs and the lows are muddy.

    I want to bring one of my 15" cabs and the Markbass LMII head I just got. I thought I'd make it easier by making the cabs maybe 20 pounds lighter, so I want to change out the EVM speaker for a neo.

    Either a Basslite 300watt, or Kappalite 450watt, but am undecided which one.

    I thought it best to do both my cabs with 8ohm, and may also use them with my SVT.

    Also thought about just doing one only with a 4ohm.

    My cabs are vented and are approx 3.3 cubic feet. Both speaker types will go as low as 1.8 cubic feet, with the basslite to 4.2, and the kappalite to 5.1, so my cabs are right in the middle.

    Any advice on which speaker type?
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    There's no advantage to the Kappalite unless you're pushing more than 250 watts, so let that be your guide.
  3. blockinlay


    Feb 21, 2009
    Phila Pa
    The LMII head is 300 watts at 8ohms and 500 watts at 4ohms.
  4. DukeLeJeune

    DukeLeJeune rational romantic mystic cynical idealist Gold Supporting Member Commercial User

    Nov 24, 2008
    Princeton, Texas
    Owner & designer, AudioKinesis; Auth. mfg, Big E (Home Audio only)
    Thanks for giving us the volume of your cab. That's very helpful.

    I made the assumption that your cab is tuned to 47 Hz; that's probably not the case, but at least it gives me a starting point for modelling so you can make comparisions.

    The Basslite 2515 is a 4-ohm driver whose calculated efficiency is 96.3 dB, based on T/S parameters. In a 3.3 cubic foot box tuned to 47 Hz, you get a +2.5 dB peak centered on about 90 Hz; -3 dB at 56 Hz; and -6 dB at 48 Hz.

    The Kappalite 3015 is an 8-ohm driver whose calculated efficiency is 97.7 dB. In a 3.3 cubic foot box tuned to 47 Hz, you get a gentle rolloff in the upper bass region with no peaking; -3 dB at 57 Hz; and -6 dB at 46 Hz.

    Another possibility is the Deltalite 2515, also an 8-ohm driver, whose calculated efficiency is 97.5 dB. In a 3.3 cubic foot box tuned to 47 Hz, you get a broad 1/2 dB bump centered on 110 Hz; -3 dB at 58 Hz; and -6 dB at 48 Hz.

    The above will hopefully give you an idea of how these three woofers would compare to one another in the bass region, even if your cab's tuning frequency is different. The Deltalite's curve looks the best to me, but that's just an opinion.

    You can eyeball the frequency response curves to see which looks the best to you through the midrange and lower treble regions:




    The Kappalite looks the best to me in the upper frequencies, but again that's just my opinion. Welcome to the wonderful world of tradeoffs.

    Excursion-limited power handling is proportional to the square of x-max, so we may assume that the Deltalite has 20% higher excursion-limited power handling than the Basslite, while the Kappalite has 70% higher excursion-limited power handling than the Basslite. What the exact power handling is depends very much on the tuning frequency of the cab so we can't go by my 47-Hz assumption; also on how your bass is tuned (low-E or low-B?); and probably on other factors that I'm not real familiar with (signal processing, playing style).
  5. blockinlay


    Feb 21, 2009
    Phila Pa
    I measured my cab to get the volume, but I just found my original plans and it's really 3.2 cubic feet. The printing was all blurry, so I looked it up and found the pdf file for my cabs online. Same exact plans I have. Awesome, I love the web.
    They are Electro-Voice TL606 plans.
    All the specs are there.
    I don't know much about Hz and dB, but I'm learning so I can make an informed decision.
    http://archives.telex.com/archives/EV/Builders Plans/TL606 Builders Plans.pdf
    I built mine around 20 years ago, but the plans are dated 1975.

    The Deltalites seem to be a better choice than the Basslites.
    Will they hold up to the SVT if I needed to turn up the volume?
    How about in the future if I decide to go with say a Thunderfunk TFB750-A?
    I will be using a bass with a low B string.
    Thanks for the help.
  6. rpsands


    Jul 6, 2007
    I would go with kappalites period, with that size box and rough tuning. The response is really nice on those things.

    They're not so much more expensive that you're saving much money going with deltalites or basslites. Maybe 30-40 bucks a driver.

    3015s can be had very cheaply here: http://www.speakerhardware.com/kappalite_3015-SPKNeoKappalite3015.php

    Basically it's +20 bucks to get a much superior speaker that'll be able to hang with much more power than you've got now. That is a no brainer imho.