Bridging vs $2000 amps
Bridging vs $2000 amps
I went to an event recently and looked into the sound system. They had 3 dual 18" horn loaded subs on each side for 12 subwoofers total. These were powered by Crown amps that were bridged and provided bone shaking bass for a crowd of about 150 at any given time. Ive always read that bridging is bad. But, how do I get to the proper amount of power without spending a shitload of money? My BFM box has dual 15" drivers in it asking for 900w. I hooked up an amp that provided 950w @ 2 ohms and it was obvious that it was underpowered. It was suggested that I needed more overhead power for the drivers which puts me up to something like a Crown 6002 at $1600. But is that necessary? Why not bridge? What would I be risking with bridging? Bridging is made out to be bad but it seems like it is impossible to power some drivers without bridging... whats the deal?
- BrentEvans
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Re: Bridging vs $2000 amps
OK Class... everyone repeat it.... WATTS ARE MEANINGLESS.
I do believe you're comparing apples and oranges. Each driver has a thermal rating in watts at a given impedance in ohms. Amps are rated for watts at multtiple impedances. 950 watts at 2 ohms is 43 volts. You can't measure watts, but you can measure volts. If your drivers are "asking" for 450 watts at 8 ohms, and are wired in parallel, you need an amp capable of 60V of output to reach that amount of power.
There is nothing inherently wrong with bridging to get to the voltage you need, as long as you deploy a limiter to prevent over-voltage.
As to the gig with three double 18s and loads of power.... there's no replacement for displacement. 6 decent 18s will move more air than 2 remarkable 15s, regardless of the cabinet configurations. A BF cab will make the most out of those 15s, though.
I do believe you're comparing apples and oranges. Each driver has a thermal rating in watts at a given impedance in ohms. Amps are rated for watts at multtiple impedances. 950 watts at 2 ohms is 43 volts. You can't measure watts, but you can measure volts. If your drivers are "asking" for 450 watts at 8 ohms, and are wired in parallel, you need an amp capable of 60V of output to reach that amount of power.
There is nothing inherently wrong with bridging to get to the voltage you need, as long as you deploy a limiter to prevent over-voltage.
As to the gig with three double 18s and loads of power.... there's no replacement for displacement. 6 decent 18s will move more air than 2 remarkable 15s, regardless of the cabinet configurations. A BF cab will make the most out of those 15s, though.
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- Bill Fitzmaurice
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Re: Bridging vs $2000 amps
Speakers don't ask for watts. They do require a specific voltage to reach full output.tuna wrote: My BFM box has dual 15" drivers in it asking for 900w
What maximum voltage output did you measure?I hooked up an amp that provided 950w @ 2 ohms and it was obvious that it was underpowered.
Re: Bridging vs $2000 amps
So I was wrong. I do believe I meant 900 @ 4ohms. The drivers are Eminence 3015LFs. I have not measured the output voltage but rather set my limiter settings based upon a calculator I found linked on this forum and which was discussed as a method of setting it all up to properly protect my speakers. With my own system I found that when I did this I the subs would quickly start clipping my amp resulting in me having to turn the limiter voltage down so that the subs hitting would hit the limiters but would not clip the amps. I figured the solution to this was a larger amp/more headroom and thus my original question.
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Re: Bridging vs $2000 amps
tuna wrote: I have not measured the output voltage
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Re: Bridging vs $2000 amps
You cannot set voltage limits with a calculator. You must use a volt meter. They are cheap.....get one. Everything gets easier...and it actually works.tuna wrote: rather set my limiter settings based upon a calculator I found linked on this forum
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Re: Bridging vs $2000 amps
Ok. I have one. I will give that a shot.