Headroom: Shuttle 9.0 into 8ohm Schroeder 12PL vs 4ohm Mesa PH212

Discussion in 'Amps and Cabs [BG]' started by TideSwing, Dec 3, 2015.


  1. TideSwing

    TideSwing Supporting Member

    Oct 31, 2014
    Las Vegas
    My current rig is a Shuttle 9.0 into an 8ohm Schroeder 12PL for two bands - 80s cover and 90s influenced hard rock original. Sounds great for both although I'm looking for more headroom with the hard rock band. My original plan has always been to add a second 8ohm 12PL but looking used right now at a 4ohm Mesa PH212, but I'm pretty open to other cabinet combos that would increase headroom. Would I increase volume significantly with more speakers? The Schroeder is so efficient, I'm not sure how it compares to other brands in a band context. Any suggestions?
     
  2. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Either a second 8 ohm 112 or the 4 ohm PH212 will make a very substantial difference to both volume and low frequency extension.
     
    B-string and barrybass33 like this.
  3. TideSwing

    TideSwing Supporting Member

    Oct 31, 2014
    Las Vegas
    Thanks, was hoping you would chime in. Does adding the second cab or single 4ohm make the amp "work" less hard? Forgive my ignorance - I suppose that is what adding headroom means?
     
  4. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    The amp will work "harder" to deliver the additional power, but this is not a problem because it is designed to do so safely.
     
  5. TideSwing

    TideSwing Supporting Member

    Oct 31, 2014
    Las Vegas
    OK got it, thanks.
     
  6. bucephylus

    bucephylus Supporting Member

    Aug 18, 2002
    Lots of experience with the Shuttle 9.0 with various TB'ers shows that the amp really opens up and does its thing into 4 ohm loads.
     
  7. TideSwing

    TideSwing Supporting Member

    Oct 31, 2014
    Las Vegas
    Great to know. I was close to trading it because I wasn't sure how much difference a 4ohm load would make. I'll just have to find the right cabinet(s) that fit my budget.
     
  8. B-string

    B-string Supporting Member

    "Headroom" gets misused a lot. Headroom is the additional sound pressure (in this case) over what you are currently using. If your amp is capable of outputting 500 watts and your cab can use all 500 watts then when not playing you have 500 watts of headroom, playing at about 100 watts you have 400 of headroom. Using a more powerful amp or a cab that take more power while one is still at the 500 watt level adds no more headroom.

    If you are in a building, note how much room you have between your head and the ceiling. That is the headroom you have, not the space between your head and the "ends of the universe". :)
     
  9. TideSwing

    TideSwing Supporting Member

    Oct 31, 2014
    Las Vegas
    I think I was trying to say something like that. I run all my knobs at noon on the Shuttle, but lately have had to push my Master Volume up to 2 or 3 o'clock with the hard rock band. That's with the 1x12" Schroeder running at 8ohms(600 watts) on the Shuttle. I was hoping that running at 4ohms(900 watts) would allow me to keep the Master Volume at noon or below. To me, it seemed like the amp is therefore "working" less cause the volume is lower but as agedhorse answered, "The amp will work "harder" to deliver the additional power".
     
  10. B-string

    B-string Supporting Member

    Chances are excellent with the added speaker you will actually use less power from the amp head. That means the amp overall doesn't work as hard, but can or will work harder if you need it.
     
    late80s likes this.
  11. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006
    Montreal
    Switching from the 12PL to the Mesa PH212 will also provide more lows on tap, in addition to the overall volume increase.
     
  12. Razman

    Razman

    Feb 10, 2005
    Orange Park, FL
    Adding speaker area increases overall efficiency so you will be louder at the same amp settings (generally - don't flame me!!) With my Mesa 400 I can keep adding cabs and it becomes quite the monster.

    The PH212 is a beast - excellent cab. I had the combo version with an M6 carbine. It could level buildings. if you like your cab tho, get a second one.

    Raz
     
  13. DC3

    DC3 Supporting Member

    Mar 30, 2005
    Atlanta
    I'm currently carrying 2-12PL's
    and a Black Jag 900. They cut through like nothing else I've tried and go down to 35hz
     
  14. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006
    Montreal
    35 Hz is..... a published claim.....and in any event, there's absolutely, positively nothing "cutting" about 35Hz.
     
  15. With ample amp, headroom is determined by cab power handling and sensitivity. Headroom is how much louder you can go for dynamic

    With 600 clean watts available into 8 ohms you are looking at maximising the potential of a 112 well before the amp. Adding another 112 cab still won't tax the amp and you would add 6dB headroom to roughly zero headroom. That's well and good but it sounds like you really are in negative headroom zone presently ( not nearly loud enough ) so you might only gain a couple of dB worth of actual headroom for dynamics.

    I would be looking for an 8 ohm 212. Then if it is not quite enough you can stack two. 900w available into that should have you turning down quite a bit.
     
  16. 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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