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Power amp RMS vs. Speaker RMS for subs

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  • #16
    Here is one of the specifications from a BBE 482i:

    Lo Contour: +12dBu adjustment at 50Hz, -10dBu input



    To those that think BBEs are a problem ... your biggest problem with this device is trying to use it with +4 gear. This model is a consumer level device and you can't run it in line with the output of a mixer. Everything else about it is an effect and just like a reverb there is a place for it and a place where it sounds bad. Operators make bad decisions all the time. It's a poor craftsman that blames his tools.
    Don Boomer

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    • #17
      You may consider running your subs mono bridged on a aux. It's personal preference, but from experience, it makes a difference. Since low end frequencies aren't directional, you really don't have to worry about a stereo image and thus both subs can hit with the same sound. BUT, be careful since you are dropping the subs and amp to 4ohms.

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      • #18
        So why would running subs bridged mono be a benefit?
        -------------------------------------------------------------------------------------------------------------------------------------------------------------------
        Former product development engineer: Genz Benz, a KMC Music/Fender Musical Instruments Company, continuing factory level product support and service for Genz Benz

        Currently product development engineer: Mesa Boogie

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        • #19
          Well one main benefit is the additional power. Under powering speakers can cause more damage than overpowering. And coupling subs is an added benefit. Like I said, it's personal opinion, but in this particular setup, I would recommend it so that he is not under powering the subs. There are pros and cons to both. I've tried both setups and have been much more satisfied with bridged mono subs. Also, running them on a aux is great for bands so that you can selectively send signal from specific tracks to the subs (ex. kick, floor tom, bass, a little keyboards) which cuts out on woofy sound from vocals and guitars hitting the top of your subs crossover point

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          • #20
            And coupling subs is an added benefit. Like I said, it's personal opinion, but in this particular setup, I would recommend it so that he is not under powering the subs. There are pros and cons to both. I've tried both setups and have been much more satisfied with bridged mono subs. Also, running them on a aux is great for bands so that you can selectively send signal from specific tracks to the subs (ex. kick, floor tom, bass, a little keyboards) which cuts out on woofy sound from vocals and guitars hitting the top of your subs crossover point

            Huge misconception.
            tlbonehead@yahoo.com
            www.myspace.com/tbone_tommy
            -For Sale:
            -set of GFS Dream 90s- gold and black pearl- $40 shipped in the cont. US
            -(2) Celestion G12M-70 16 ohm guitar speakers in good condition $40 ea. + shipping.
            - Vox VT15 Valvetronix very clean - $85 + shipping
            - Hughes Kettner Edition Tube 20 (the early Voxy sounding one) Sounds & looks good. $250 + shipping. SOLD
            - Crate Palomino V8 - 10" Celestion - Very clean - on Ebay (sold)

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            • #21
              I disagree. Many engineers and I agree that under powering speakers may cause more damage. But I don't wish to argue the point.

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              • #22
                But to add on, the reason I say that is, this person seems to be looking for a little more power out of his subs and he say's that he has heard popping. This leads me to believe he is pushing his amp near clip, which in turn does add distortion to the signal. Distorted signal is a major cause of speaker damage.

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                • #23
                  But to add on, the reason I say that is, this person seems to be looking for a little more power out of his subs and he say's that he has heard popping. This leads me to believe he is pushing his amp near clip, which in turn does add distortion to the signal. Distorted signal is a major cause of speaker damage.
                  I'd better quit using my fuzz pedals. They create square wave distortion. You seriously don't think the popping is a mechanical thing? Sounds to me like the VC is bumping against its limits. Bad!
                  tlbonehead@yahoo.com
                  www.myspace.com/tbone_tommy
                  -For Sale:
                  -set of GFS Dream 90s- gold and black pearl- $40 shipped in the cont. US
                  -(2) Celestion G12M-70 16 ohm guitar speakers in good condition $40 ea. + shipping.
                  - Vox VT15 Valvetronix very clean - $85 + shipping
                  - Hughes Kettner Edition Tube 20 (the early Voxy sounding one) Sounds & looks good. $250 + shipping. SOLD
                  - Crate Palomino V8 - 10" Celestion - Very clean - on Ebay (sold)

                  Comment


                  • #24
                    I know you know what I mean by this. This is sad. I just wanted to recommend a way to boost overall performance here. I've used those particular subs before in both stereo and mono setup, needless to say any type of sub for that matter. If you believe running them in stereo at 8ohms is better, then please say so, otherwise, if it were me, I would run them bridged mono at 4 ohms as does most major venues across the US. If he plans on playing music were low end frequencies will be panned hard left and right and that effect is wanted, then I see no reason why not to stay in stereo. But otherwise, I don't see a reason not to run mono. Every major setup I have worked on (minus only one that I can think of where a stereo image for the subs was wanted by the FOH engineer) we have run our subs mono.

                    If you prefer it that way, then I have no problem with that, I tailor to peoples wants.

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                    • #25
                      For that matter I've never understood how you'd do crossover with the subs on a (post fader ?)aux or sub. I see folks post about it once in while but haven't seen a detailed description of how it's "done". I normally run subs off the mono sub output of my Behringer xover but running them stereo with the pan pots centered is the same thing, no?

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                      • #26
                        Everybody knows that square waves open up a direct portal to Hell and the flames blasting though the portal are what burns out your drivers .

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                        • #27
                          For that matter I've never understood how you'd do crossover with the subs on a (post fader ?)aux or sub. I see folks post about it once in while but haven't seen a detailed description of how it's "done". I normally run subs off the mono sub output of my Behringer xover but running them stereo with the pan pots centered is the same thing, no?


                          You just need another channel of crossover. You would send you normal mid/high signal to one crossover or one channel (depending on your setup) and then send the aux output to the other crossover or channel.

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                          • #28
                            For that matter I've never understood how you'd do crossover with the subs on a (post fader ?)aux or sub. I see folks post about it once in while but haven't seen a detailed description of how it's "done". I normally run subs off the mono sub output of my Behringer xover but running them stereo with the pan pots centered is the same thing, no?
                            If you run them off of an aux out you control what and how much low end come through on each individual channel by adjusting the corresponding aux knob on each channel.
                            tlbonehead@yahoo.com
                            www.myspace.com/tbone_tommy
                            -For Sale:
                            -set of GFS Dream 90s- gold and black pearl- $40 shipped in the cont. US
                            -(2) Celestion G12M-70 16 ohm guitar speakers in good condition $40 ea. + shipping.
                            - Vox VT15 Valvetronix very clean - $85 + shipping
                            - Hughes Kettner Edition Tube 20 (the early Voxy sounding one) Sounds & looks good. $250 + shipping. SOLD
                            - Crate Palomino V8 - 10" Celestion - Very clean - on Ebay (sold)

                            Comment


                            • #29
                              Well one main benefit is the additional power. Under powering speakers can cause more damage than overpowering. And coupling subs is an added benefit. Like I said, it's personal opinion, but in this particular setup, I would recommend it so that he is not under powering the subs. There are pros and cons to both. I've tried both setups and have been much more satisfied with bridged mono subs. Also, running them on a aux is great for bands so that you can selectively send signal from specific tracks to the subs (ex. kick, floor tom, bass, a little keyboards) which cuts out on woofy sound from vocals and guitars hitting the top of your subs crossover point


                              +1 on the aux fed subs. As far as bridging the amps, the OP just needs to make sure he will have adequate AC power available as the amp will draw more current when bridged, especially is he is hitting it pretty hard.

                              Comment


                              • #30
                                +1 on the aux fed subs. As far as bridging the amps, the OP just needs to make sure he will have adequate AC power available as the amp will draw more current when bridged, especially is he is hitting it pretty hard.
                                Very true. But if the VC s on the woofers are already bumping against their limits, I'm pretty sure more power is only a solution to getting new subs cuz the current ones will be dead.
                                tlbonehead@yahoo.com
                                www.myspace.com/tbone_tommy
                                -For Sale:
                                -set of GFS Dream 90s- gold and black pearl- $40 shipped in the cont. US
                                -(2) Celestion G12M-70 16 ohm guitar speakers in good condition $40 ea. + shipping.
                                - Vox VT15 Valvetronix very clean - $85 + shipping
                                - Hughes Kettner Edition Tube 20 (the early Voxy sounding one) Sounds & looks good. $250 + shipping. SOLD
                                - Crate Palomino V8 - 10" Celestion - Very clean - on Ebay (sold)

                                Comment



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