Hey guys so I think I messed up :(

I have 4 Behringer B212XL speakers. The woofers in the speakers had blown so I decided to upgrade them to more powerful woofers. The out of box woofers were 200W continuous, so I upgraded them to Delta 4A 400W woofers. I think this was big mistake.

The highs out of the speakers sound much louder than they should. This makes sense I imagine as the woofers need more power now. Additionally, I imagine that the circuit/driver in the speakers is not made to work with the bigger woofer.

Is there anything I can do? Can I build some type of low-pass-amplifier to even out the sounds (when I try this on a mixer it seems to distorte the sound)? or is the circuitry in the speaker not sufficient for the woofer. Is there any rewiring I can do in the driver? Or buy a new driver?

Thanks for your help.

2 Answers 2


This makes sense I imagine as the woofers need more power now.

That doesn't make sense because your new woofer although 400W has a sensitivity of 98dB 1W/1m compared to the old one at 95dB. which means it only takes 0.5W to drive the new one as loud as the old one.

It is recommended that the amplifier has a power double the continuous wattage. So your problem might not be the new woofer but the power amplifier you are using may only be a 5-6 hundred watt per channel amp?

  • Thats true. My amp is about 750W and im running it at about 70%. I didn't think about that. Jul 29, 2018 at 0:09
  • Also, what is the circuit in the speaker? The input goes to the circuit which appears to have some resistors, capacitors, and inductors. Then it splits +/- to the tweeter and woofer. Is this just a passive low/high pass filter for the woofer and tweeter respectively? Is there any down side to powering the woofer and tweeter individually direct from the amp and doing my own EQ with a mixer? Jul 29, 2018 at 0:10
  • @HurricaneDevelopment I would guess it’s just a simple crossover. What you are talking about it bi-amping and you could but you would need a separate output for each woofer and tweeter. It can’t be done with just a channel EQ through the main LR. So you’d need to use 2 channels of the amp for one speaker Jul 29, 2018 at 0:27

Have you wired both woofers with correct polarity (same wires to red connector as previously, and both wired in the same manner to the amp)? If they are out of phase with the other woofer, the bass is very much reduced.

If they are wired out of phase with the tweeters but both in the same manner, matters are a lot more subtle and mainly concern the crossover frequencies.

Have you soldered/made the connections well? Speakers take a lot of current: a bad connection can reduce that.

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