To bridge or not to bridge

[louisiana21v]

That's one thing I was worried about. My buddies new (2010) Centurion Enzo is running three of these amps and I was impressed with them, so I ordered one to run my new tower speakers. Mabey I jumped the gun a little. I usually over analyze everything.

So if I just run them of 2 of the 4 channels would that be under powered?

[wolfeman131]

JMvotto is correct. They sure are. My Buddy just got his new Mojo yesterday and it's running at 2 ohms for the rear cockpit speakers.

What? Gisepi doesn't own a camera or did I miss the pics?

[WaterBullDawg1980]

What? Gisepi doesn't own a camera or did I miss the pics?

I think our kumputers are broken. I don't see no piks eeether.

Sent from my bag phone using Tapatalk Dos

[louisiana21v]

So the Kicker 350.4 was waiting at my door when I got home from work. The certificate said 425 watts total. I hooked it up straight not bridged and measured the ohms at the amp while running, it read 3.0 exactly. Considering the actual output and the 3ohm load I figure its close to 100 watts per channel this way (or is this wishful thinking), that's about double what my old amp was pushing. It was too late for a good test, but considering I have less than $400 in this upgrade I think this is gonna be a good bang for the buck deal.

[501]

I would definitley try bridging it. If it goes into protect, then wire back. only takes a few minutes to try.

[newty]

Maybe I'm missing something but if you bridge a 4ch amp two channels with 1 speaker to each channel, you get a 2 ohm output from each of the 2 channels (roughly doubling the amp output). You add a second speaker to each channel now you've doubled the output again and dropped the impedence load to a 1 ohm which will likely send the amp into protect and/or cause the amp to overheat. Assuming the amp is not 1 ohm stable, it will not last long.

Be sure to check the owners manual on the amp to insure the amp is up to the task.

There is a learning curve to this stuff and I encourouge folks to research this stuff before commiting. It will cost you more in the long run if you dont.

[louisiana21v]

That's what I always though too, bridged equals 2ohms, but that is based on using 4ohm speakers right? The manual states bridged power is 175 watts at 4ohms not 2ohms, that confused me. I think they mean 4ohm speaker load. These speakers are 3ohm which would present a 1.5ohm load. Correct??

[cab13367]

Maybe I'm missing something but if you bridge a 4ch amp two channels with 1 speaker to each channel, you get a 2 ohm output from each of the 2 channels (roughly doubling the amp output). You add a second speaker to each channel now you've doubled the output again and dropped the impedence load to a 1 ohm which will likely send the amp into protect and/or cause the amp to overheat. Assuming the amp is not 1 ohm stable, it will not last long.

Be sure to check the owners manual on the amp to insure the amp is up to the task.

There is a learning curve to this stuff and I encourouge folks to research this stuff before commiting. It will cost you more in the long run if you dont.

That's what I always though too, bridged equals 2ohms, but that is based on using 4ohm speakers right? The manual states bridged power is 175 watts at 4ohms not 2ohms, that confused me. I think they mean 4ohm speaker load. These speakers are 3ohm which would present a 1.5ohm load. Correct??

Guys, this is not the way it works. I think you guys are confusing wiring speakers in parallel with bridging an amp. Wiring two speakers in parallel does reduce the total load that the amp sees (for example, if you wire two 4 ohm speakers in parallel, the amp sees a 2ohm load).

But the load that the amp sees (measured in ohms) depends on the speakers being used, NOT on whether or not the amp is wired bridged or standard. Most amps I know of are stable down to a 2 ohm load when wired one channel per speaker, and down to a 4 ohm load when wired bridged (two channels per speaker). I am not an electronics engineer so I don’t know why that is. But I know for sure that if you wire your 350.4 bridged to drive your pair of 3 ohm speakers, your amp will see a 3 ohm load per side which it is not designed for.

So if I were the OP, with two tower speakers rated 100W continuous, I would return the 350.4 and look for a 2 channel amp that is rated at least 125W RMS per channel. This will give you a bit of headroom on the amp so that you are not running it full tilt when you want to crank it up.

Also, if your goal is to hear your music while wakeboarding, be forewarned that you WILL be cranking it up and you still will not be able to hear it that well over the wind and engine noise.

BTW, the 350.4 is rated 60W @ 4 ohms, and 90W @ 2 ohms, so with your 3 ohm speakers, you are probably getting somewhere around 75W rms out of your amp to each speaker if you wire it one channel per speaker (this assumes an inverse linear relationship between resistance and power, which I am not sure is correct). But for sure, it will be somewhere between 60W and 90W.

Hope that helps.

[louisiana21v]

That makes sense. Thanks man. I may have another use for this amp, but I'll have to run it for now. Definitely don't think I'm gonna bridge it.

[501]

Well although the speakers aren't "exactly" 4 ohms, they aren't a 2 ohm speaker and are just 6.5" Co-axials not 15" Subs. I would bridge it myself. You won't "break" the amp. The worst thing that it could do it go into protect mode and I'd bet it wouldn't even do that. I have bridged amps to a 2ohm load many times without issue even if it doesn't spec it. In this case since it's driving small full range speakers I would bet it would be fine. Its double the power from the same amp for your tower speakers.