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Headroom?

Discussion in 'Amps and Cabs [BG]' started by Vinpaul, Sep 27, 2005.


  1. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus
    Can I please get some opinions on this issue. How big a part does it play in your tone? Im most likely going to buy a GK 1001rbII head, 700 at 4 ohm. Th other amp Im considering is a Genz Benz, 420 at 4 ohm, 600 at 2. Now the guy working trying to sell me the GK is saying its headroom will be way beta then GB, but how much will this effect me? If I can get enough volume out of either one (and I need a loud amp which both are from what Ive heard) then how much of a big deal is the headroom? thanks heaps Id appreciate any input.

    BTW as I understand it headroom is the difference between what the amp is putting out and what it can put out, ?
     
  2. Lot's of discussion on this if you do a search. You will get some great info on the impact of higher wattage, etc.

    A couple of things that I learned through experience and also from other TBers on this site.

    1) While 'a watt is a watt', published watt spec's are hard to compare across manufacturers. There are 'loud' 300 watt amps, and 'soft' 400 watt amps, based on the quality of components, how the preamps are voiced, etc.

    2) You have enough headroom in any amp if you are not pushing it past its safe operating zone.... so its hard to say if 700 watts will give you more headroom than 400, all other things being equal (which in this case they are not!). The 700 watts will give you more headroom in an absolute sense, but not if you are only pushing each amp below their maximum power.

    3) The sensitivity of your speaker(s) has at least as much to do with volume and headroom as the absolute wattage.... 400 watts into a high efficiency speaker like an Epifani, Schroeder, etc. will sound very different than 400 watts into a low efficiency speaker like an Acme, for example (low efficiency speakers aren't bad, by the way, they just need a lot of watts... but you get a more extended low end for the trouble!).

    I find the GB stuff to be very conservatively rated, so in this case, I would make my choice based on which amp sounds the best to you, versus pure wattage.

    I'm sure other TBers will chime in with specific comments on the two amps. I really like the sound and features of the GB myself.
     
  3. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus
    thanks mate, yeah Ive read that bout GB too fact they are sposed to be conservatively rated so its down to the tone I guess. I just found out that schroeder cabs are being distributed here in OZ :bassist: so I will almost definetely be ordering one of those, either 410 or 21012. Another questions arises though, will the 2 heads Im looking at have enough power to drive these schroeder cabs? The cabs are roughly 1000 watts at 4 ohms, GK is 700 GB 425, so no headroom I spose? Or if I say only turn my head a third of the way Id have a little?
     
  4. Hello. I really like my 1210, and it is very efficient (i.e., it gets very loud based on the wattage you put in).

    Remember, the cabinet power rating is based on the maximum power suggested for the safe operation of the cab, it has nothing to do with how much power the cab needs or how many watts you 'need to put in it'.

    Given that Jorg's cabs multiple speaker cabs are 4ohms and very efficient, either of those heads would be great with the Shroeder's.
     
  5. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus
    well then it sounds like Im gonna have a much improved rig in about amonths time :) Didnt see that ur a schroeder owner, and another happy one at that, cant be coincidense :) gonna go down tomorrow and try both heads again, see how they go
     
  6. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Adequate headroom helps you maintain your tone at higher volumes by not distorting. It doesn't effect your tone directly.

    The CLEAN difference. In general, yeah, that would be how much headroom you have.

    I would get the GK. I own a GK 700RBII and I love it. Great tone and LOUD.

    Because I am a GAS addict I am constantly wanting to get the 1001RBII but cant really justify it because this head works so well! I am sure that one day I will own one.

    :D

    Joe.
     
  7. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus
    yeah, i looked at the 700rbII but for a little more spose its worth the extra 250 watta or whateva it is.

    I realistically would never need to turn my amp more than halfway I dont think when playing with the schroeders, so take it they would be powerful enough so I can still get a good clean tone? Sorry bout these questions by the way, its not an issue I knew much about but Ive been getting some great answers here and am reading other threads about this stuff as we speak so I think Im getting somewher getting a hang of it...slowly :p
     
  8. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    If I could do it over again I would definitely get the 1001RBII! At the time I bought the 700RBII I was still learning alot about amps and headroom. Hindsight is a wonderful thing aint it?

    I don't own any Schroeder cabs so I can't say for sure but I'm willing to bet that the 1001RBII will be plenty of power for most applications. 700w is alot! (assuming a 4 ohm cab)

    It's o.k. to run a 100w amp with a 1000w cab as long as you realize that all you really have is a 100w rig. If you get the 1001RB you will have a 700w rig and like I said, that's alot!

    :D

    Joe.
     
  9. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus
    thanks joe, yeah good thing this guy at a store turned me onto this whole headroom deal. My current head is a hartke 350! :bawl: not just lack of headroom though, I just dont like it. And yeah the schroeders are 4 ohm so Ill get the whole 700 out of it
     
  10. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Not turning your amp more than halfway doesn't mean you're guaranteed to be using only half the power. Under the right (or wrong) circumstances, you can be driving an amp to its full power with the volume knob on 50%, or less.
     
  11. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Cool. That means that with the GK head your new rig will be twice as loud!

    Congrats!

    :D

    Joe.
     
  12. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    If you're asking about MY tone, I'll say "not much", but that's because as of now I don't really go for a punchy 'headroom-tone' for what I've been doing.

    ..Far from it: I've been aiming for more of a synth-y or organ-like tone. I have a CS-3 compressor squishing everything right from the get-go, and THEN an Aphex low-freq compressor (Big Bottom) right after that. On top of all that, I often run a light overdrive next in the chain, and THEN I've got the preamp gain AND the boost up pretty-good on the 700RBII head. (!) ...So as you might imagine, all the headroom in the world wouldn't do my tone much good.

    Not-for-everyone, for-sure...

    I'll probably grow out of it, I imagine.

    Joe
     
  13. The difference between as loud as your rig will go cleanly and the volume you want to play at is really your headroom.

    You don't just look at "the speakers are 400W and my amp is 800w so i have 400W of headroom". Your 100w combo has plenty of headrooom for a coffeehouse gig.

    Having said that, one aspect of headroom IS that your power amp can put out more wattage than the cab can handle continuously. Your 400W RMS cab can certainly handle peaks of 800, or even 1600 W occasionally. That's +3dB and +6dB respectively, or the "Music power" rating of the cab (subjective as hell, by the way).

    Making sure your amp can handle those "extra" wattage peaks cleanly without clipping allows you to get the max out of your speakers, without clipping ruining the dynamic range, and potentially blowing tweeters.

    If you're at the edge, say averaging nearly 400w into your 400w cab, you're better off doing it with an 800W amp than a 400w amp, since the 400w amp will be clipping on the peaks.

    The problem is it is very difficult to know when you're at that limit. Listen for distortion, back off. Cause certainly with an 800w amp, you surely CAN avg more than 400W into the 400W rms speaker and blow it.

    So having extra amp headroom (amp RMS output > spkr RMS power rating) makes you MORE and LESS likely to blow your speakers... :D :eek: :confused:

    More likely to melt the voice coils, less likely to pop a tweeter. You pays your money, you takes your chances.

    But generally, I would guess the avg power is probably less than we think it is. If you have meters on your power amp, I think you'd be surprised how low the actual avg power generally is. Lots of transients in live music, and the "avg" level is way under those. Not so true for recorded music, its compressed, the avg is much higher, the peaks less severe than live.

    Randy
     
  14. nysbob

    nysbob

    Sep 14, 2003
    Cincinnati OH
    I like lots of headroom - I play a passive Fender and I've found by using pretty powerful tube amps that are operating well within their "comfort zone" I have an amazing amount of dynamic range available. No matter how hard I dig in or smack the bass, the amps & cabs can handle and reproduce it. :D
     
  15. David Vega

    David Vega

    Aug 28, 2002
    Puerto Rico
    ok! good thread,

    I have a SVT4PRO, sometimes I run this puppy on bridge mode, in a BXT410HL4, that handle 600watts rms. I have this set up about 1 year, I have the SVP-BSP conected to the SVT4PRO. The SVP preamp have a lot of gain, I am using all master volumes halfway (12 o'clock setting)

    REcently, 2 speakers were blown!! same setup, same setitng. I dont know if using this SVT4PRO in bridge mode cause a gradual degradation on the speakers.

    I am in the process of getting a QSC PLX1602, and this thing is high wattage!!

    So any recommendation suggestions on how handle this, "headroom" thing, is very welcome

    thanks
     
  16. Basically any signs of distortion is a warning to turn down.

    The best way to handle headroom isn't looking at having enough "amp headroom" to drive the speaker to the brink of destruction...

    If you have enough speakers to handle the volume you need for the rooms you play, you never have to drive them so hard that the amp is nearing the point where damaging the speakers is a problem.

    You need adequate power, and adequate speaker area. Putting a ferrarri motor on a scooter doesn't do any more good than putting racing slicks on a yugo. You need power AND traction to get anywhere. Getting enough speaker to easily handle the volume you need, AND enough power to drive that speaker, including transients, so its done cleanly, is your best defense against blown equipment.


    People focus on "twice the amp power for the speaker", trying to maximize what you get out of the speaker, thinking that is the right approach. But not if you try to take that optimized single 10" cabinet/amp combo and play a large gig with it...

    Volume requires power and cone area. Find what you are weakest, correct that problem. Sometimes its more speaker, sometimes more watts, sometimes both, sometimes its a tossup.

    Randy
     
  17. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    ASSUMING that you're running a 'clean rig'.

    I can goose-up the Boost knob on my 700RBII, and just let'er quack-away! It's MADE to do that.

    I can even run up into like all-out 'lead guitar' distortion with it, if I want (at low volumes, even, using the master ("woofer")-volume), but pedals work better for that.

    Joe
     
  18. Who is the distributor? Got a website/email or anything??
     
  19. True... and there's nothing wrong with that, I was referring to safely going with more amp power than speaker capacity... if you like distortion, last thing you need is more power than the speakers can handle, unless you also like replacing speakers with your distortion! :D

    Randy
     
  20. Vinpaul

    Vinpaul

    Aug 24, 2005
    Melbourne, Aus

    www.greensquare.net Its not on website yet, but e mail em. They said theyll be getting some stock in bout 3 weeks. All these responses are great, but so would u all say even at 425 watts at 4 ohm amp like a GB 600 would be enough to go with an efficient schroeder 410?