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Ohm/Watts help needed

Discussion in 'Amps and Cabs [BG]' started by The Derwood, Jan 16, 2019.


  1. The Derwood

    The Derwood

    Jul 9, 2018
    Good Afternoon,

    I have two eminence CA1059s which are 10" drivers with 500 watts and 8 ohms
    I'm looking to make another cabinet with a 15" driver also 500 watts and 8 ohms

    Q1. Should I run the two tens in parallel or in series
    Q2. What power requirements should I look for with the amp head?

    Any help is greatly appreciated.

    Sincerely,
    Darren
     
  2. NKBassman

    NKBassman Lvl 10 Nerd

    Jun 16, 2009
    Winnipeg, MB, Canada
    If you combine the two 10" speakers in series the cab will be 16 ohms. If you combine them in parallel, the cab will be 4 ohms.

    What are you hoping to achieve by adding another 15" driver into the mix?
     
  3. mmbongo

    mmbongo Five Time World Champion Supporting Member

    Aug 5, 2009
    Carolinas
    Yeah those do not mix well. Best best is to get 16 ohm 10's, or a 4 ohm 15 and get a 2 ohm stable amp (Mesa Subway).
     
    NKBassman likes this.
  4. ThisBass

    ThisBass

    Aug 29, 2012
    Germany
    From where did you get this wisdom?
     
  5. It's pure Physics, the power distribution won't be even.
     
    Relsom, DiscoRiceJ and NKBassman like this.
  6. FunkHead

    FunkHead Supporting Member

    Mar 10, 2007
    If the 210’s combined are 8 ohms, then just daisy chain the 15 off of it. If the 210’s are total of 4 ohms then they will be louder than the 115 as they will see more power.
     
  7. ThisBass

    ThisBass

    Aug 29, 2012
    Germany
    With every speaker (two 8 Ohm 10"s and one 8 Ohm 15") wired in parallel the power distribution was equal.
     
  8. That's assuming the amp head can handle a load that's lower than 4 Ohms.
    I'm assuming the minimum load the amp is rated for is 4 Ohms, but the OP has not specified.
     
    NKBassman likes this.
  9. ThisBass

    ThisBass

    Aug 29, 2012
    Germany
    Honestly, the cabinet total Ohm number tells nothing about the number of loaded drivers.
     
  10. mmbongo

    mmbongo Five Time World Champion Supporting Member

    Aug 5, 2009
    Carolinas
    Yeah I'm re-thinking this. It's confusing.

    Usually when you see a 2x10 with a 1x15 you have two 16 ohm speakers and one 8 ohm speaker. The Ampeg cabinets I had last year are a perfect example. Each cabinet was 8 ohms. You don't have three 8 ohm speakers, that why I say they don't mix well.
     
  11. NKBassman

    NKBassman Lvl 10 Nerd

    Jun 16, 2009
    Winnipeg, MB, Canada
    Well it would be less than 4 ohms, for one. So depending on the amp that might not work.
     
  12. 500w for one 10'' driver is highly suspect, not much less for the 15 if it's a full range bass guitar speaker. Looking up specs for the 1059 its RMS is 250w.

    Seeing as you have the drivers you may as well build the cabs and see what you get. Eminence give suggested boxes for each driver.

    Series or parallel on the tens depends on what you have for amplification.
     
  13. JimChjones

    JimChjones

    Aug 6, 2017
    SE England
    Strictly they are 250W RMS drivers. Eminence would be worth asking, but there's a 4ohm 300W Ca154 in the same series. If you put the two 10s in parallel and the 15 in series with the pair you'd get a rig capable of 600W, but my rather uninformed look at the numbers suggests those particular 10s might not be the best mix with 15s.

    I think the safe (and talkbass conventional ) option would be to get two more of the 10s and build an identical pair of ported 2x10s. Put the drivers in series to make 16ohm cabs and they d run to 1KW and 8ohm.

    But your band cultivates a sensible on stage volume a 4ohm 500W 2x10 would be all you'd need. In your place I'd build the 2x10 and see how it goes. You could always find a broken 15 and construct a dummy 15 cab as an cab stand to both get the 10s near ear height and provide the look [grin]. Remove the magnet and you could build the fake cab out of nice cheap and light 4mm ply!
     
    Last edited: Jan 16, 2019
  14. AudioTaper

    AudioTaper Supporting Member

    Sep 23, 2018
    Make or Buy a 1x15 cabinet? I would suggest buying one, especially if power handing and Ohms law is getting the best of you.

    Depending on the amp you want to use (and if its 2 Ohm stable) I would get a 4 Ohm 15" cabinet. More power by itself and matches up with the 4 Ohm 2x10 cab (two 2 Ohm in parallel) if you play a 5-string, some sort of crossover/HPF might serve you well on the 2x10 to keep it clean.

    What about selling the current 2x10 and getting an 8 Ohm version and an 8 Ohm 1x15? I cant think of a head that wont handle 4 Ohm loads. As far as power requirements, that kinda depends on how loud you are going to be playing... Headroom is a good thing, so I would look for something in the 400-700 Watt RMS neighborhood. Always use RMS power ratings, not peak.

    I used to have an 8 Ohm 2x10 and a 4 Ohm 1x15 for a total load of 2.6 Ohms. Worked out well since I was using a 2 Ohm stable Peavey T-Max head.

    Edited to correct mistake -
     
    Last edited: Jan 17, 2019
  15. Relsom

    Relsom Supporting Member

    Nov 23, 2013
    The Old Dominion
    They will see more power but won't neccessarily be louder.
    If each 10 were 8 ohms and it were me I would opt for a capable 8 ohm 15 cab and parallel run the 2 10s in series. You won't get full power from the amp but distribution would lean towards the 15, since I suspect those 10s can't actually handle the power the OP stated.
     
  16. BogeyBass

    BogeyBass Inactive

    Sep 14, 2010
    It's ok man life is easy.

    You already have a pair of matching 10s
    Wire them in series for 16 ohms

    Then buy another pair and build a matching pair of 2x10s
    Also in series for 16ohms

    Then you have 8ohm load with both cabs in parrallel
     
  17. This is a good plan. Any of the modern gigawatt, I mean 800w, micro amps can give the 8 ohm 410 tower a good push, should be plenty loud with ''only 500w''.

    If I am reading between lines properly OP has only bought the two tens so far?
     
  18. Rip Van Dan

    Rip Van Dan DNA Endorsing Artist Supporting Member

    Feb 2, 2009
    Duvall, WA
    ***BEWARE***
    Hooking up a 4 ohm 115 and a 4 ohm 210 in parallel will give you a 2 ohm load not an 8 ohm load and will damage your amp if it has a 4 ohm minimum ohms rating. if his amp will do 2 ohms, he would be fine but he will be putting a 2 ohm load on his amp not an 8 ohm load by hooking two 4 ohm cabs together in a parallel connection (industry standard).

    Hooking them up in series would result in an 8 ohm load, but will require a special box or cable to do it.
     
    AudioTaper likes this.
  19. mmbongo

    mmbongo Five Time World Champion Supporting Member

    Aug 5, 2009
    Carolinas
    Killed_by_Death likes this.
  20. AudioTaper

    AudioTaper Supporting Member

    Sep 23, 2018
    You are completely correct, and I need to proofread my posts better.
     
    Rip Van Dan likes this.
  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.

     
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