Amp bridged mode question

[Shaun]

Hopefully the tech savvy among you can help an old man out. I've used mostly active systems so just need clarification on a passive query.

I have an amp that can handle 4ohms on Bridged mode. Is there any problem in running 2 passive bass bins in parallel (both are 8ohm bins)? [ AMP (bridge mode 4ohm) into Bass Binn (8om) thru to another Bass Bin (8ohm).

I have a spare amp sitting that would be suitable if running as above. However, in normal (unbridged mode) it doesn't have the power I would need for the these cabs.

[Excalibur]

As long as the amp is happy to run at four ohms bridged ( which in effect is two ohms per channel, so youy manual should state that it is two ohm stable in stereo) there ought to be no problem. Don't overdrive it, cos things may get hot. Allow plenty of ventilation

[Shaun]

As long as the amp is happy to run at four ohms bridged ( which in effect is two ohms per channel, so youy manual should state that it is two ohm stable in stereo) there ought to be no problem. Don't overdrive it, cos things may get hot. Allow plenty of ventilation

Power at 4 ohm: 2 x 950 W
Power at 8 ohm: 2 x 550 W
Power at 2 ohm: 2 x 1250 W

Bridge mode 1 x 4000 W at 4 ohm, 1 x 2800 W at 8 ohm

So all looks good. :) Thanks Peter.

[djeddie]

Power at 4 ohm: 2 x 950 W
Power at 8 ohm: 2 x 550 W
Power at 2 ohm: 2 x 1250 W

Bridge mode 1 x 4000 W at 4 ohm, 1 x 2800 W at 8 ohm

So all looks good. :) Thanks Peter.

Eh??? If the power is 1250W per channel at 2Ω, then the [bridged] power will be 2500W at 4Ω not 4000W. An amp can't just add 1500W simply by bridging! Something says to me they're not true power ratings. What's the make and model?

[Shaun]

Eh??? If the power is 1250W per channel at 2Ω, then the [bridged] power will be 2500W at 4Ω not 4000W. An amp can't just add 1500W simply by bridging! Something says to me they're not true power ratings. What's the make and model?

https://www.thomann.de/gb/behringer_ep4000_europower.htm

[djeddie]

Ah, I see. The Berry EP4000 is actually an EP2500 that they decided to re-badge and use peak ratings instead of the RMS output. The Ep2500 was also a copy of the QSC RMX 2540... but using a smaller transformer. The new power ratings are also taken at 1KHz, not anywhere near the LF section of audio, so they will be nowhere near that power when used as a bass amp.

The actual power ratings of the 2500 (and 4000) in real-world measurements are roughly 450W at 8Ω per channel, 750W at 4Ω, and 900W at 2Ω, so 900W at 16Ω bridged, 1500W at 8Ω bridged and 1900W at 4Ω bridged. You can see the result of the small power supply here, as it should be double the power as you halve the impedance. The power supply cannot deliver the current at lower impedances.

I know from a band PA perspective that they do work on LF applications but... never let it get anywhere near clipping, especially if you're using it at 2Ω per channel (the same as 4Ω bridged).

[Shaun]

Ah, I see. The Berry EP4000 is actually an EP2500 that they decided to re-badge and use peak ratings instead of the RMS output. The Ep2500 was also a copy of the QSC RMX 2540... but using a smaller transformer. The new power ratings are also taken at 1KHz, not anywhere near the LF section of audio, so they will be nowhere near that power when used as a bass amp.

The actual power ratings of the 2500 (and 4000) in real-world measurements are roughly 450W at 8Ω per channel, 750W at 4Ω, and 900W at 2Ω, so 900W at 16Ω bridged, 1500W at 8Ω bridged and 1900W at 4Ω bridged. You can see the result of the small power supply here, as it should be double the power as you halve the impedance. The power supply cannot deliver the current at lower impedances.

I know from a band PA perspective that they do work on LF applications but... never let it get anywhere near clipping, especially if you're using it at 2Ω per channel (the same as 4Ω bridged).

Very helpful indeed. Thanks Eddie. :beer1::beer1:

[djeddie]

:beer1: No problem at all.