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in reality 1000w isnt *that much* louder than 350w

Discussion in 'Amps and Cabs [BG]' started by ::::BASSIST::::, Jun 17, 2005.

  1. ::::BASSIST::::

    ::::BASSIST:::: Progress Not Perfection.

    Sep 2, 2004
    Vancouver, BC Canada
    I have a stewart pr 1000 poweramp. I tried it tonight bridged at 1000w 4ohms and also with one channel 350w @ 4ohms with my schroeder mini 12+ (4ohms). Though 1000w was louder than 350w it sure didnt seem like over double the volume to me.

    I think i read on TB that if you have 100w you would need 1000w to double the volume. That seems true.

    So aside from the headroom issue, does it really matter if you have 400 or 700 watts if the volume difference is negligible?

    Or is headroom the only issue?
  2. playmybass


    Mar 28, 2004
    Tucson, Az
    To double the volume, you have to times it by ten. so for your amp to be 10 time slouder, it would have to be 3500 watts.
  3. I like watts
  4. thesmallprint


    Jan 4, 2005
    i think you mean twice as loud or 437 500 watts
  5. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    Just one thing to point out.

    350 watts into a single 12 won't be much quiter than 350 watts into a single 12.

    However, 1000 watts into two 12's would be alot louder.
  6. Secondhandloser


    Mar 28, 2005
    You mean 1000 into a 12 won't be much louder than 350 into a 12, right?
  7. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    It is all about headroom. For the most part amps of adequate size for the application run at around 10% of their actual rating, so ideally your 350 watt amp is cruising along at perhaps 35 watts average output. However, transient peaks can easily run 10dB higher than average output, so having the ability to handle those peaks without the amp farting out requires 350 watts.

    But if you're playing outside, for instance, and have to crank the amp up higher, to maybe 100 watts average output, that leaves you 650 watts shy of being able to handle your transient peaks. That's when having 1000 watts available is of benefit. It certainly has nothing to do with being able to provide a constant 1000 watt signal into a twelve, as that would only serve to cook the voice coil.

    As to one versus two 12s, parallel wired you'll get an additional 6dB output doing so with the same amp assuming the amp can handle the lower impedance load.
  8. yup, headroom it is all about!
  9. It's true. That 87 Celica I used to have didn't have much headroom, and I'm not exactly huge.
  10. BassJunkie730


    Feb 3, 2005
    IF i bridge my PLX to the full 1600w?

    That would be just shy of double the reccomended RMS power for the cab. I'm pretty sure I have the components to do it (12 AWG Speakon Cable), Or better yet should I combine a another cab (8ohms) to drop the impedance to 2.67 ohms RMS and still use one side at nearly 700 something watts? Could I induce thermal shut down?

    My delimma is that I'm clipping my amp all the time to get the volume I want. (500w) But I like being able to run two cabs.

    I'm starting to think that the way to go is a tuba 24. that way I'd still run the rig stereo but I'd free up a lot of watts by crossing the schroeder 1210 at about 100hz and let the Tuba take over from there.
  11. Go ahead and give it a shot with the full amp wattage. BE CAREFUL!! You will find time and again on this board reccomendations to run with an amp rated around twice the speaker rating. Only rule of thumb is to turn it down if it sounds bad.

    Clipping is much worse and headroom.
  12. How many ohms is the 1210 cat, and what ohm ratings is the 1600W at? If 1600W@4 ohm bridged amp drives an 8 ohm speaker, its only putting out around 1000W @ 8 ohms.

    So if the 1210 is rated at 800W, and its an 8 ohm cab, you're barely over the RMS value of the cab. 1000w into a 800w cab some would say is not enough power (for transients, headroom). Doubling the power of your cab isn't that excessive anyway, as Bill said, between peaks and lower volume notes, plus especially space between notes (@0 watts) tend to bring the long term avg down.

    I just thought of this also, could you guys make sure I'm not nuts if you don't mind..... Here's my new theory.

    Don't underestimate the benefit of space between notes either. Imaging a car ride @ 60mph. Take a 15 min break every hour (0 mph). Your avg speed plummets to 45mph. Thats equivalent to only inserting a 1/16 note rest every beat. So a 600W amp playing real live 600w notes on the "1 e and" then resting on the "a" is only averaging 450W. Now imagine space between songs. Between sets. RMS rating of cab is the "long term avg", not sure how long term they mean, but I believe its hours. Cause its measuring heat buildup in the voice coil causing damage.

    Thinking your 1600 W RMS amp will put out 1600W RMS while you're playing is like thinking you're going to drive cross country with a station wagon full of 3 year olds drinking soda pop and average 80 mph for the trip, when you're only able to go 80MPH when you're driving to avoid tickets.

    What do you guys think? Good analogy?
  13. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    Well, yeah...
  14. Joe Beets

    Joe Beets Guest

    Nov 21, 2004
    To double the volume of a stinking little 350 watt amp is easy. PLX3402, bridged. To double the volume of a puny little 500 watt amp is a little more weight, RMX5050. ;)
  15. Funky Doctor

    Funky Doctor

    Aug 28, 2003
    But double the volume of something is stupid louder. I want to be in headroom city when i play, and i am.
  16. BassJunkie730


    Feb 3, 2005
    The Schroder 1210 is Rated at 850W RMS at 4 ohms.

    Would you all still reccommend bridging the PLX 1602 to 1600W RMS at 4ohms?

    I'll defer to Beets since he seems to be the High Wattage Junkie around here. :D
  17. I'm not Beets, but I would say yes to that question. Like wurmhole said, just turn it down if it sounds bad. I don't think you'll have a problem as long as you back off a little on the power amp gain and not play stupid loud. If you need more volume, you need more speakers to help you move more air.
  18. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    Yes. I run 900W into each of my 350W rated Low-B2 cabs and they're very happy with it.

    If you see the amp clipping/limiting turn down. If you hear the cabs farting (over-excursing) turn down. (Or reduce your lows).

  19. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    The general rule of thumb, and I will emphasize that it is both very general and only a rule of thumb, is that your target amp power point would be about double the loudspeaker system's continuous power rating. That's because of the dynamic nature of music and other typical audio; if you avoid significant clipping, you can almost always be pretty well assured that the amp's average output power will be somewhat below the continuous average power rating of the loudspeakers.

    I exceed that 2:1 ratio a bit, though; I run my PLX 1602 in bridged mono into an EV 1150M cab. It's an 8-ohm system rated at 200 watts continuous. Except for turn-on and turn-off muting, I've only seen the clip LEDs flash two or three times in seven years. ;) My usual playing style probably helps, too, because I find that thump, punch, etc., depends not only on the notes I play tight with the drummer but also at times on how much space I put between them. I don't play legato unless the song requires it. ;)
  20. wyleeboxer

    wyleeboxer Supporting Member

    Apr 28, 2005
    Orange County, CA
    I like watts

    Thats funny stuff!

    Real simple, I got a SWR 350watt head while my GK 1000watt head got repaired. I really like the SWR and pretty much all I need. However, when I got the GK back and relized that a 1000watts of head room sounds huge not necessarily louder, I put the SWR on the reserve team.

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