I just got 2 12" Audiobahn Sound Qs, (ALUM12Q). They are rated at 1000 RMS a piece. I used a PowerAcoustik 1800DB to power them which gave each sub about 625-700 watts, (1.5 ohm load). Now, after just a week of running one has already gone. It didnt over exert the cone and there was no audible distortion before it went. The coils inside burnt up. (Tap the cone and it sounds like a chain link fence). Using an ohmeter i measured no resistance at all on the coils.


My question is, is this a manufacturer defect or did I mess this one up? Or has Audiobahn produced a sub that cannot hold what they say it can?

Don't know if it matters, but these subs were in a sealed enclosure made out of 1" MDF with 2.5 cubes of air space each.

I highly doubt the sub was rated for a 1.5 Ohm load. Most subs are only capable of 4 Ohms. Running it at such low resistance would burn it up.

Originally posted by Silv Blt
I highly doubt the sub was rated for a 1.5 Ohm load. Most subs are only capable of 4 Ohms. Running it at such low resistance would burn it up.

The ohm rating of a sub notes what resistance the sub places on the amp. Placing subs in different configurations creates an ohm load on the amplifier, you can't create an ohm load on a sub....just doesn't work that way.

I've never liked Audiobahn subs so my first instinct is to tell you to stop buying junk, but that's just me.

The Sound Qs have dual 6 ohm coils. Two subs paralleled with their coils paralleled will give you a 1.5 ohm impedance at the amplifier.

Personally I don't think the products Audiobahn is coming out with is "junk". Maybe I blew this one from under powering it, even though I did not hear any distortion from any clipping from the amplifier or speaker distortion.
I remember back in 97 when they first came out they weren't anything in quality when compared to Stillwater/Kicker or Soundstream. But now Audiobahn is decent. (I still love my Kickers though).

Has anyone else ever heard of a sub overheating or blowing from being under powered but not from over exursion, amp clip or speaker distortion?

Distortion will kill a sub faster than too much power. Distortion causes much more heat in the voice coils, which can burn them up. The ability for a sub to "handle" a lot of power(1000 watts is alot of power handling), the sub needs a way to dissipate all the heat generated from all that power. Vented pole pieces, and ferro fluid cooling help greatly, but only to an extent. Since these were sealed boxes, then getting cool outside air to the voice coils is pretty much non existant, esp when the air inside the box is already heated. What is the cone material made out of? I have the Eclipse aluminum cone 15", and I've put well over 1000 watts to that sub, and it takes every last watt of power i can put at it. Since this sub is all aluminum, it can dissipate the heat generated very well, very quickly. I can actually feel the heat on the cone of the speaker. I'd be willing to bet that your subs just cant dissipate the heat generated, quickly enough, esp when listening to them loud for extended periods of time.

Also, really low frequencies, like 20-40 HZ, can generate LOTS of heat, because it takes the most amp power to reproduce these frequencies, esp when you want them "loud" Play a bass CD at 20 HZ for like 10 seconds, and you can feel the heat in the cone of the speaker already..This can kill a sub's voice coil VERY quickly, esp when it can't dissipate the heat fast enough. If you want to push that kind of power on a sub, and like to have it loud for long time frames, get a sub that has a aluminum cone, and a motor structure that is vented very well. Audiobahn's subs aren't that bad, but there are many higher quality choices out there..When it comes to car audio, you always get what you pay for. A sub that can truely handle that kind of power, and continuously take it, isn't going to be cheap.

The power akoustic amps are somewhat over-rated power wise also. On am amp like that, figure about 75% of its rated power is actual "clean" power

Good point. I was tired when I posted and was thinking backwards. lol

I would recomend actually reading up on the speaker before you talk about it. Sound Qs have a solid one piece spun aluminum cone, cast aluminum basket and the coils have black aluminum wrapped around them for better heat dissapation and a vented pole piece. I also posted on the first post that there was no sound distortion.

And for your low frequencies cause more heat, YOUR WRONG. With a larger enclosure it takes more current to produce higher freguencies than low. If I was to adjust my crossover so that I could reproduce 100 HZ, i would burn up a sub like nothing. But at 20-40HZ i could play it for hours and not burn it up. Believe me, I've done it with Kickers and a large enclosure. Your theory would be true on an enclosure with limited air space. The enclosure type and displacement determines at what frequencies you will ge the best response and require less power and the frequencies at which you will require the most power and create the most heat.

I am not new when it comes to car audio. I've been working on car stereo for over 12 years now.

If you're such an expert then why the fuck are you posting here for a response? Go to a 12volt forum. Sorry, I hate audiobahn subs.

Uhh yeah, if you are an expert of 12 years, then why ask about a crappy blown sub? You should know exactly what caused it to blow, with your years of expertise! I've never heard anything good about Audiobahn..take it for what its worth. Go spend some real money on a sub that can take the abuse. After working in the audio field for 12 years, you should know what the "good" stuff is ;)

I've been doing audio for shops for longer than you have..I've competed in DB Drag Racing events, and have 4 trophies to prove it..then I got out of audio and into making cars fast..One thing i hated about car audio, is that everyone thinks they know everything :rolleyes

Originally posted by XtremeRS
Uhh yeah, if you are an expert of 12 years, then why ask about a crappy blown sub? You should know exactly what caused it to blow, with your years of expertise! I've never heard anything good about Audiobahn..take it for what its worth. Go spend some real money on a sub that can take the abuse. After working in the audio field for 12 years, you should know what the "good" stuff is ;) I've been doing audio for shops for longer than you have..I've competed in DB Drag Racing events, and have 4 trophies to prove it..then I got out of audio and into making cars fast..One thing i hated about car audio, is that everyone thinks they know everything :rolleyes

Yup, I've been doing it for 12 years too and I'm the first one to go "Really, hmmm, I didn't know that" cus I know I don't kow everything. I know a lot, but not as much as someone else sometimes.

Actually, what he is talking about is box resonant frequency. With a sealed box, is mostly up to the amount of airspace available, and sub characteristics. YOu can build and "tune" a sealed box to be the loudest at a certain frequency, with minimal amplifier power. This is exactly what i did when i competed in DB drag racing. I had a 96 Grand Prix, and used 2 of the Eclipse aluminum cone 15's, in a ported box, ported up through the rear deck, and speakers firing into the cabin, trunk sealed off from the cabin. With much trial and error, and MANY speaker box designs(Top Box computer design software), I found that the car's natural resonant frequency was around 42-43 Hz( I used an Audio Control SPL meter/analizer). I then used the top box software to design a ported box that was "tuned" for around 43 Hz. These subs were not designed to run in a ported box, and they didnt have a flat frequency respone at all, but damn, it was low, and it was LOUD. I believe my highest SPL score was close to 160db, using just the 2 15's, and 2 Directed 1100d's..ahh those were the days..eh, at least I still have my hearing :)

Originally posted by XtremeRS
Actually, what he is talking about is box resonant frequency. With a sealed box, is mostly up to the amount of airspace available, and sub characteristics. YOu can build and "tune" a sealed box to be the loudest at a certain frequency, with minimal amplifier power. This is exactly what i did when i competed in DB drag racing. I had a 96 Grand Prix, and used 2 of the Eclipse aluminum cone 15's, in a ported box, ported up through the rear deck, and speakers firing into the cabin, trunk sealed off from the cabin. With much trial and error, and MANY speaker box designs(Top Box computer design software), I found that the car's natural resonant frequency was around 42-43 Hz( I used an Audio Control SPL meter/analizer). I then used the top box software to design a ported box that was "tuned" for around 43 Hz. These subs were not designed to run in a ported box, and they didnt have a flat frequency respone at all, but damn, it was low, and it was LOUD. I believe my highest SPL score was close to 160db, using just the 2 15's, and 2 Directed 1100d's..ahh those were the days..eh, at least I still have my hearing :)

I'm about to make you cry LOL

We hit a 162 with a simple truck box and two 10" L7's running off a Memphis 1000D in a Civic CRX ;)

Since you guys are already off topic. What are your opinions on the best setup for a full size standard cab chevy pickup. I have a friend that wants to be very loud. Lemme know what u think.

Gabe

Originally posted by sek95GS
Since you guys are already off topic. What are your opinions on the best setup for a full size standard cab chevy pickup. I have a friend that wants to be very loud. Lemme know what u think. Gabe

Nah, start a new thread dude.

Originally posted by a_miller_76
Nah, start a new thread dude.

oh alright, heh

Originally posted by a_miller_76

I'm about to make you cry LOL We hit a 162 with a simple truck box and two 10" L7's running off a Memphis 1000D in a Civic CRX ;)


Miller, i have much respect from reading your posts over the years, but im calling you out on that one. I know you can make huge dbs with a crx but there is no way you hit 162 with that set up. Please tell me you were just busting this guys balls. Was the spl meter at the bottom corner of the windshield? Thats amazing if you really did.I would have loved to have heard. I've only heard 1 160+db vehicle and that was the Fosgate S10 Extnd Cab. With a wall of 8 12's Hx2's i believe. Dont know that was a while ago. Oh and by the way, My experiences with Audiobahn have varied, old stuff was shit, new stuff ok.

It sounds like a bad gain setting, or an amp that isn't rated to handle low ohms.

Try setting the amp's gains using a perfect sine wave output from the headunit (I use a CD with pre-recorded waves), use an oscilloscope to find the max clean output voltage of your head unit. Then use the oscilloscope on the amp's outputs with a 1.5 ohm load on it, but the gain turned to the lowest setting. You should still see a perfect sine. Only raise the gain up to a point where you see any distortion.

BTW This is a great calculator-
http://www.woodartistry.com/linkwitzlab/closed-box1.xls

You might not have heard the distortion, and it may not have been clipping at all, but if you were putting too much wattage into too little resistance, the speaker would turn into a nice little heater coil due to too much voltage.

Without diving into a science lesson, check out this chart-


You can see that if the resistance is way out of spec, you can have rediculously high voltage, the amperage output will be low (amp cant take it), you'll still have close to the rated wattage until your speaker coils melt.

Anyways, if you want a really simple answer, here you go: Buy an amp rated at close to double the power of the speakers you want to use, AT the ohm load listed in the spec sheet. Only look at RMS power ratings. It's expensive at first, but cheaper in the long run if your goal is to push serious power.

it sounds like he actually thought his audiobahn equipment could handle what it was rated for... take 25% of 1,000 watts RMS and you have the real RMS power of that shitbox driver. you didn't notice any distortion or anything because you just NUKED the coil from vastly overpowering the sub.
audiobahn = garbage

couple of things may have gone wrong here, one is that you bought audiobahn, thats the biggest one of them all, second is that if they are brand new you may not have broken them in properly, third is that the amps were not tuned right and distortion killed subs like it always does, fourth is that it is possible that you got deffective equipment

dont forget forth dude... he mentioned the was "NO DISTORTION" Bull shit... there is no such thing.. just because u cant hear it doesnt me its not there... if u have 0% distortion u much have a shit load of sq trophies bro! Whats your secret? (sarcastic)

02:19:18pm DarkOne> They'd have had to brought a whole fucking JUG of KY.
02:19:28pm InFiNiT3> lol no shit
02:19:39pm DarkOne> and a funnel.
02:19:45pm grain> have to get the ky with warming
02:20:00pm InFiNiT3> i feel sorry for the 18 y/o (one was 17 one 18) his name was plaster'd all over the news n news paper
02:20:06pm DarkOne> Yeah, has to be warming.
02:20:06pm BuckNutty> jus spit on it and it'll go in
02:20:17pm InFiNiT3> aye the ky w/ warming any good>
02:20:45pm grain> never tryed it
02:20:50pm grain> i applyed for a sample on thier website
02:20:56pm BuckNutty> evan didn't complain any
02:20:56pm BuckNutty> it felt nice
02:20:57pm InFiNiT3> lol
02:21:01pm grain> i use id glide whne she dries
02:21:06pm grain> good stuff
02:21:45pm InFiNiT3> thnx for the new sig guys
02:21:45pm DarkOne> Are we still talking about fucking dead chicks?