infinitebass

Um, like I said, you're more likely to blow a speaker by running less power than more. How were they wired up deified?

Blake

deified

From what I understand:When changing your ohms you are increasing the current your using by a cetain percentage. The guy said something about bridging his amps channels. I was saying "IF" you are going to bridge you should use a less powerful amp because your changing that current to the speaker. If the amp is continually giving the sub more watts than it can handle it will eventually give out, or burn out. So, I guess I don't really understand, when you say give it more power. How do you blow a speaker with less power from an amp? I don't think I've heard that before. Isn't the speaker designed to take a certain amount of power (peak wattage) and has an ideal wattage to use? Like mine is 800w-1200w peak. so I have a 4-channel 1000w bridged 2 channels per sub. This would actually put my power below 800w. I haven't had any problems and I use the hell out of them. I may have missed something here so please explain it to me again. I don't mind taking critisism as long as someone can explain what I've done wrong. Thanks.

infinitebass

This is usually more noticeable when running mids and highs, and doesn't apply as much to subs, since they are more forgiving.

What happens, and this usually occurs when running speakers off of a head unit, is when you push the power of the source, whether its the head unit or an amp, it goes into clipping. I don't know how much you know about audio, but that means the signal goes from a nice smooth sine wave to a square wave (if you know this, I apologize). The square wave causes the speaker coil to leave the magnetic gap, which causes the the coil to heat up A LOT, much more than too much power causes it to. Why this happens, I forgot. I'll try and figure it out. But regardless, if your source has started to go into clipping, you're much more likely to blow your speakers.

And so, when you have more power, you get a much cleaner signal. Granted, you have a 1000w going to a 500w speaker, turn the power all the way up, it will blow the speaker.

What kind of subs do you have? On the one you blew, did you have both voicecoils wired in? And don't forget, peak power is not RMS. RMS wattage is much more important. If your sub has a 8-1200w peak power rating, the chances are its RMS rating is around 250w, maybe up to 350w. And if your amp isn't running full power, then you probably aren't getting nearly the full wattage out of it.

BTW, can you give me a link to info on the amp you were running? And how did you have the voicecoils wired? Did you have the voice coils of one sub wired in parallel to one channel, or were the voicecoils wired in series? I'm assuming the subs were dual 4 ohm voicecoils, correct?

Blake

deified

I thought you were saying to get an amp that would push more watts than your speakers peak wattage. Nevermind, I'm dumb. Now I get what your saying. I had to bridge to get this amp to work my subs.

Yes, dual 4ohm voice coils. Both voice coils were bridged to one pos/neg terminal on the box(one for each sub). then I have that terminal bridged to two channels giving it around 500 (dispersed so a little less) per sub. less than peak, more than rms. My ohms tested at bout 1.5 I believe which really makes the 12"s kick hard. I really need like a 2000w amp then bridge to get better potential out of my subs.


I thought clipping just made the speaker sound funny, not blow it. Also, I thought it was just with cetain head units. Huh, thanks for the heads up.

Sorry if I miss led anyone, you should never have your amp power less than rms. But the ohm trick should still work, just make sure your not pushing more watts than your speaker at limited ohms. KABLOOEY!!

infinitebass

I'm still trying to figure out how it was running at 1.5 ohms.

You have one sub on two channels. That channel was bridged, which doesn't change the ohms. But you had to 4 ohm voicecoils run in parallel to each channel (two channels bridged to one), which would make it a 2 ohm load.

Is that right?

Blake

deified

Yes, that is what was weird to me too. I came up with the same math you did but when I checked it with an electronic Ohm device it said 1.5. I checked and rechecked and just assumed that it must have been right, because everything was working properly the way I set it up. The sub seems like it has a different ohm set up than I thought. I'm gonna have to go back and check.

infinitebass

I forgot...you can't exactly measure the resistance of a speaker using a multimeter, I don't think. I assume you had it playing at the time, right? Because if you look at the graphs they should give you with decent speaker, the actual resistance varies in conjunction with load, power, etc.

Blake

KeithC

Your measuring the speakers DC resistance with a multi-meter. Different speakers will vary but most 4Ohm speakers will have a DCR of around 3.8Ohms. 1.5Ohms for two in paralell sounds low but possible. Make sure your not measuring the speakers with them hooked to the amp. That will change the reading.

The Impedance of the speaker is what is different at different frequencies. The load that the speaker presents to the amplifier is more closely related to Impedance.