Are my subs blown/blowing?

Question

I have 2 12" Pyramid Royal Reds which are each 600 watts RMS/1200 watts peak. As an amp, I had a limited budget and purchased an Alpine 400W Mono. I noticed that it was much louder to just have one sub hooked up, so I unhooked the right woofer and let the amp push all its power into the other.One day when I was driving my sub just cut out, and I was left with no bass. I asked a friend of mine that works with subwoofers and he told me since he could push it in and it dind't smell or make any weird noises that it probably was not blown and that the wiring just came loose inside the box. My amplifier still powered up, and I didn't feel liek taking the sub out of the box to re-wire so I just hooked up my other subwoofer to the amp and called it a day. Lately I've noticed that the subwoofer is not as loud as it used to be, and makes a slightly weird noise when it's on low, like a rattling noise. Is there anything I can do to make sure my first sub isn't blown, and my second isn't going to?

Answer 1

everyone gave you some pretty good advice but i just want to tell you that you should take the time to LEARN about car audio before you start disconnecting and rewiring stuff

a subs impedance (ohms) is very important- for example: a sub that can take 600watts RMS @ 2ohms will be very under powered if you send it 600watts @ 4ohms (it will play distorted, melt the voice coils, and be trash), and by the same token if you send 600watts RMS @ 2ohms to a sub rated at 600watt RMS @ 4ohms it will be over powered

matching RMS wattage at the correct impedance is also very important- you dont want to over or under power you subs

If you send too much power to your sub, you risk damaging it. The cone of the speaker and the mechanical parts that make it move may break under the stress. Surprisingly, too little power can also damage your subwoofer — in fact, it's actually more common than damage caused by overpowering.

When the volume is turned up and the amp doesn't have enough power, the signal becomes distorted, or "clipped." This distorted signal can cause parts of the speaker to overheat, warp and melt. Not good!

You don't have to match speaker and amp wattages exactly. An amp with a higher output than the speaker's rating won't necessarily damage the speaker — just turn the amp down a bit if you hear distortion from the sub and don't run the speaker at extremely loud volumes for lengthy periods. Likewise, you'll be OK with a lower powered amp if you keep the volume down and don't feed a distorted signal to the sub.

the number or voice coils is also very important- DVC or SVC

with a single voice coil sub you can only get one impedance (ohms), but if you have dual coils you have the option of wiring it up for two different impedances

so depending on the impedance and number of voice coils a sub has it will determine the amount of wattage needed

also when you add or subtract a sub from your setup you usually end up changing the impedance at the amp, therefore over or under powering the sub

Answer 2

yes. you can take a multimeter for few bucks and measure the resistivity of the voice coil. if it is higher than 10 Ohm or infinite, your speaker is deaaad. You can measure the second one and again - gently push the center of the cone to hear if something scratches.

Answer 3

An easy way to tell if a sub is blown is if you can push it in and it makes really scratchy sound. That means you blew it up.  If it is a clean/ quiet motion, then odds are your sub is fine. I would say you have a loose wire somewhere.  Maybe inside the box.

Answer 4

i dont think the suc is blown like your friend said, sometimes you will geta rattle from loose wiring from the speaker to the box, or it could be air leaking from where the sub meets the box and you only hear it at low volume because otherwise the speaker is to loud