Another dumb question for the ages

[POST]

How can i tell when my subwoofer is at or past its max and its getting damaged ....ie "redlining the woofer"....?

I know you're going to say one of the things is "when it gets distorted" but its not getting distorted and i keep putting it up but i have to stop because it sounds like its shaking all the screws in my altima loose. How esle would it be getting damaged? I just like these subs and it took me a day to put them physically inside my trunk... So if they blow out or die within the next year and a half i'm going to be pretty upset.


Also, whats the best way to take care of your subwoofers? to prolong its lifespan while still being able to turn it up loud every once in a while..?

[Notladstyle]

How can i tell when my subwoofer is at or past its max and its getting damaged ....ie "redlining the woofer"....?

I know you're going to say one of the things is "when it gets distorted" but its not getting distorted and i keep putting it up but i have to stop because it sounds like its shaking all the screws in my altima loose. How esle would it be getting damaged? I just like these subs and it took me a day to put them physically inside my trunk... So if they blow out or die within the next year and a half i'm going to be pretty upset.


Also, whats the best way to take care of your subwoofers? to prolong its lifespan while still being able to turn it up loud every once in a while..?

if you want your subs to last forever, buy an amp that has a peak output that is less than or equal to the subs RMS power handling.

I know my subs bottoming out when the surround makes a kind of sputtering noise over the bass.

[POST]

uhhh, i thought you were supposed to get at or ABOVE the peak output, reason being that distorted sound volume thats tried to be played more than the amp could accurately handle damages the subs more than having accurate but slightly more excessive power

The sputtering sound, how long can you have that going on before it really screws the subs up? so when im testing i can go from front of the car and back

[Bumpin Expo]

when you hear ding ding or sputters the bass

[TJElite]

uhhh, i thought you were supposed to get at or ABOVE the peak output, reason being that distorted sound volume thats tried to be played more than the amp could accurately handle damages the subs more than having accurate but slightly more excessive power

The sputtering sound, how long can you have that going on before it really screws the subs up? so when im testing i can go from front of the car and back

To answer your question, if your amp is not clipping, you run very little risk of damaging your woofer, even at 2-3 times its rms rating of musical power (no 5 minute sine bombs, etc.)

Mechanical damage is different, and can kill a woofer very quickly. How much power will damage a woofer mechanically is dependant on many variables, including box size and design. Sometimes you can hear the damage (bottomed out voice coil) sometimes its harder (torn surround). Unfortunately, in either case, damage occurs very quickly. Again, I need more info (speaker, box size and design) before I can really even guess at the mechanical damage possiblity.

Now, if you, or others reading this want more on the subject, scroll down...






There are two common failure modes for a sub...thermal failure of the voice coil or mechanical failure of the moving assembly.

Thermal failure can come from too much power, but more often comes from over driving the amp, causing clipping, which basically sends a square wave to the sub. This makes lots more heat than a normal, unclipped wave. This is why I prefer to put people into bigger amps, rather than smaller ones. Bigger amps will get louder, cleaner, with less chance of the owner driving them into distortion. The RMS power rating is a continuous rating, and is almost useless. Unless you listen to nothing but sine waves, you'll never need to worry about it. You can give the sub 2-3 times (often more) its RMS rating in bursts, which is what most music looks like to the sub. This is why you often see 'peak power' or 'musical power' ratings that are much higher. You could blow a 500 watt rms woofer with 200 watts (or less) of distortion, while a 200 watt rms woofer will probably survive at 500 watts of clean, music power.

So, even at 2-3 times the RMS power (in the form of music) you're really pretty unlikely to damage the voice coil thermally. What's more likely is mechanical damage, and things like box size and design play a role in this. For example, a woofer in a smaller sealed box will take more power to reach its mechanical limits than the same woofer in a larger sealed box. Many people interpret this to mean that smaller boxes are louder, but this is not always the case. Since larger boxes allow the woofer to move further on the same amount of power, they are more efficient...the woofer will play louder on lower power. For the same woofer excursion, a smaller box will see more pressure, as well. This can lead to failure such as surround damage. This does not mean build the biggest box you can, though, as the air behind the woofer acts like a spring, an keeps bad things from happening, like voice coil former damage.

To give you an example, I have a customer with 4 crossfire 12's in a big ported box, on 4 1000 watt amps. He beats on it pretty hard, and has yet to hurt a woofer. My installer has one of the same 12's on a 600 watt amp in a smaller, sealed box. He has had the surrounds blow out on 2 woofers so far. BTW, this particular woofer only has an RMS power rating of 375 watts.

Ported boxes present a slightly different problem. Contrary to some people's belief, a woofer in a ported box does produce pressure inside the box. As you go up in frequency vs. the tuning frequency, the pressure builds. On the other side, as you go below the tuning frequency, the woofer 'unloads' or essentially loses the air spring of the box. Bad things can happen here, like the above mentioned voice coil former damage.

In short, amp power, on its own, doesn't mean as much to woofer longevity as people often believe. Its just one factor that must be considered.

Toby

[POST]

wow Tjelite, it was a good read, very informative, thanks.

I can tell you exactly what i have... but before i do no one make fun of me or tell me my purchases were garbage or whatever, it was best i could do on budget at the time and after what i've gone through with it i like it a LOT and consider it a good buy.
sooo. --

Subs Polk - db212-2 -- Link -- http://www.crutchfield.com/S-vGZXhwHPjSr/cgi-bin/ProdView.asp?search=107db2122&i=107DB2122

Amp - Boss Riot GT2500D -- Link -- http://www.cardomain.com/item/BOSGT2500D

Also everything is wired completely properly, i did wire it myself and it was my first time wiring anything but it sounds great and runs great, grounded perfectly.

So.....yeah you can get the specs from the links.

Thanks again TJelite, i appreciate everything much =D


btw heres what it looks like in my car =X

http://myspace-931.vo.llnwd.net/00622/13/92/622642931_l.gif
:D :nerd: :cool: :P :roll:

[rys]

I would mount that amp somewhere but I think that setup looks pretty cool, I like the box (aesthetically speaking)

[Notladstyle]

wow Tjelite, it was a good read, very informative, thanks.

I can tell you exactly what i have... but before i do no one make fun of me or tell me my purchases were garbage or whatever, it was best i could do on budget at the time and after what i've gone through with it i like it a LOT and consider it a good buy.
sooo. --

Subs Polk - db212-2 -- Link -- http://www.crutchfield.com/S-vGZXhwHPjSr/cgi-bin/ProdView.asp?search=107db2122&i=107DB2122

Amp - Boss Riot GT2500D -- Link -- http://www.cardomain.com/item/BOSGT2500D

Also everything is wired completely properly, i did wire it myself and it was my first time wiring anything but it sounds great and runs great, grounded perfectly.

So.....yeah you can get the specs from the links.

Thanks again TJelite, i appreciate everything much =D


btw heres what it looks like in my car =X

http://myspace-931.vo.llnwd.net/00622/13/92/622642931_l.gif
:D :nerd: :cool: :P :roll:

with the gains set right theres no way u will blow those subs.

[POST]

I would mount that amp somewhere but I think that setup looks pretty cool, I like the box (aesthetically speaking)


yeah it looks nice.

Unfortunately i dont know anything about mounting anything anywhere =/

the amp is literally sitting there not screwed or bolten down to anything. Amazingly, it doesnt move around at all (think of the same concept of radio towers being held up by steel cables) it stays pretty suspended in the same spot.

Any ideas of how to mount that thing?

thanks

[POST]

with the gains set right theres no way u will blow those subs.


how would i set the gains wrong...? :crack: :oops:

[rys]

yeah it looks nice.

Unfortunately i dont know anything about mounting anything anywhere =/

the amp is literally sitting there not screwed or bolten down to anything. Amazingly, it doesnt move around at all (think of the same concept of radio towers being held up by steel cables) it stays pretty suspended in the same spot.

Any ideas of how to mount that thing?

thanks

My back seats have zippers on the back, I unzipped them and slid in some 3/4 MDF (cut to fit) and then screwed my amps into that.

[POST]

My back seats have zippers on the back, I unzipped them and slid in some 3/4 MDF (cut to fit) and then screwed my amps into that.

errr, wouldnt that get poor ventilation?

but i dont think it'd affect my amp much, it runs surprisingly cool, but that may be BECAUSE it is out in free air haha, though i have to keep it generally in the location where it currently is, the grounding cable isnt the longest (which is for the best) and i am not planning on buying another one.

[TBSpyder]

Generally if you hear a popping noise, your woofer is bottoming out, in which case it can be damaged. Too large of a box can also cause a woofer to over-extend, damaging and eventually blowing it. IMO, ported subs are much more prone to damage and failure due to this reason as well. Distortion can kill a sub, which is usually due to insufficient power, box design, and/or crossover points. Howver, too much power and/or excessive volumes can equally damage a sub by melting voice coils and such.


Definetly get that thing mouted up somewhere out of the way. The location you have it now, even if it was screwed down, makes it extremely vulnerable to something coming in contact with any of the terminals and possibly shorting something.

[Notladstyle]

how would i set the gains wrong...? :crack: :oops:

I couldnt explain that clippin sounds like but the goal is to have the amp gain set below the output voltage of the deck. like if the amp manual says that it goes to 8v and you have a 4v output deck you should be pretty near the middle or below on the amp gains.

some amps have it written on them - like it will say .2v on one side and 8v on the other - 8v is actually the lowest gain and .2 would be a crazy clipping signal. You shouldnt use the gain as a volume, it should be set based on what the hardware specs say the HU/amp are capable of handling.

[POST]

Definetly get that thing mouted up somewhere out of the way. The location you have it now, even if it was screwed down, makes it extremely vulnerable to something coming in contact with any of the terminals and possibly shorting something.

as you can see, my trunk is literally empty besides the two things, the only other thing i keep in there is a towel and its completely out of the way. All my car emergency tools are in the little compartment above it.

The only easiest thing i can probably do is make a little wall seperating it from anything i'd ever put back there.

thanks for the heads up.

ps what does 'bottoming out' mean? from what i can infer it means just getting to the max it can go, but what's it technically mean? =/

[TBSpyder]

as you can see, my trunk is literally empty besides the two things, the only other thing i keep in there is a towel and its completely out of the way. All my car emergency tools are in the little compartment above it.

The only easiest thing i can probably do is make a little wall seperating it from anything i'd ever put back there.

thanks for the heads up.

ps what does 'bottoming out' mean? from what i can infer it means just getting to the max it can go, but what's it technically mean? =/

Even if something does not come in contact with the amp, it could slide or be pushed and pull a wire out...shorting against the amp or something else. Besides the possibility of a short, the vibrations can easily kill an amp as well.

[POST]

I couldnt explain that clippin sounds like but the goal is to have the amp gain set below the output voltage of the deck. like if the amp manual says that it goes to 8v and you have a 4v output deck you should be pretty near the middle or below on the amp gains.

some amps have it written on them - like it will say .2v on one side and 8v on the other - 8v is actually the lowest gain and .2 would be a crazy clipping signal. You shouldnt use the gain as a volume, it should be set based on what the hardware specs say the HU/amp are capable of handling.


Hrm well... on my amp i have a switch that selects either 100mV-2V or 2v-8V. Currently i have it set to the first one; i THINK i tested the other one (2-8 ) once before but it didnt do anything or no sound came out... but i dont remember

Based off my hardware (btw i have an Alpine CDE-9845) is that what i should be running or did i screw up?


In response to tbspyder -

err so wtf should i mount it to!? my car's trunk is completely made of metal or something and i dont know where i would screw it to..
Only thing i've been thinking of was getting a big block of wood roughly a couple of inches bigger in each dimension besides thickness and putting it under my carpet thing and then i would screw the amp through the carpet and into the wood, would that work..? =[

[TBSpyder]

In response to tbspyder -

err so wtf should i mount it to!? my car's trunk is completely made of metal or something and i dont know where i would screw it to..
Only thing i've been thinking of was getting a big block of wood roughly a couple of inches bigger in each dimension besides thickness and putting it under my carpet thing and then i would screw the amp through the carpet and into the wood, would that work..? =[

There's several things you could do. The best would be to get a piece of thin wood (slightly larger than the dimensions of your amp), like plywood, and first mount it to the back of your seat, and then screw your amp to that. You could also mount it directly to your sub box. The vibrations of high output systems could damage the amp, but given the equipment you're using, I think it would be fine. You would then want to mount your box down as well so if the whole thing were to slide, the wires would not pull out. Thirdly, if you're really lazy and don't really care, you could velcro it down in the location you have it...although this would be my least recommendation.

Besides the saftey factor, mounting the amp down securely (with screws) makes it just a little harder for a theif to steal as well. As you have it now, all someone has to do is pop your trunk and rip it out...gone in less than 2 seconds.

[POST]

There's several things you could do. The best would be to get a piece of thin wood (slightly larger than the dimensions of your amp), like plywood, and first mount it to the back of your seat, and then screw your amp to that. You could also mount it directly to your sub box. The vibrations of high output systems could damage the amp, but given the equipment you're using, I think it would be fine. You would then want to mount your box down as well so if the whole thing were to slide, the wires would not pull out. Thirdly, if you're really lazy and don't really care, you could velcro it down in the location you have it...although this would be my least recommendation.

Besides the saftey factor, mounting the amp down securely (with screws) makes it just a little harder for a theif to steal as well. As you have it now, all someone has to do is pop your trunk and rip it out...gone in less than 2 seconds.


Yeah i had that idea, but not to the back of the seats because my sub box is formed to lean against it completely so theres no room unless its sandwiched in there and then it'd get deadly amount of vibrations.. and im not screwing it to my sub box because i....just dont want to damage it... so im just sticking it to the floor i guess


As for the possibility of my subs being stolen... theres no way in hell they can get it out, literally...

the whole thing weighs 90 pounds, the trunk mouth is too small for it to fit, i had to completely remove the rear seats and spent hours fitting it thru there.. and my amp would have the highest and easiest possibility of getting stolen but then again it isnt the highest quality amp and not that expensive so it wouldnt be that great of a loss.

Although i'd really like to see someone try and open my trunk to steal something, that'd be funny.

[TBSpyder]

4 small screws isn't going to really "damage" your sub box you know, I'm assuming the sides are carpeted? Otherwise you could mount it to the side of your trunk, against the wheel well or something, using the same wood technique as the back seat. Just be sure to check the other side of where you're screwing to be sure you don't hit a gas line or something. Use short screws.

[POST]

=[

but wouldnt the thing MAKING the vibrations vibrate the most?

[TBSpyder]

=[

but wouldnt the thing MAKING the vibrations vibrate the most?

Yes, and it could damage the amp...but the equipment you're running shouldn't vibrate it to that extent. Setups I've seen that have killed the amp by mounting it to the box were usually like JL w7's on 1k watts. ;)

[Notladstyle]

=[

but wouldnt the thing MAKING the vibrations vibrate the most?

vibration robs power, your box shouldnt be moving enough to damage the amp at all. if it is your subs are not properly mounted of hte box isnt properly braced. I think your headunit has 4v outputs, no alpine has less than 2v so you should be on the second setting. using the first setting makes it possible for the headunit to send a signal that the amplifier cannot reproduce without clipping - as in it will attempt to amplify it beyond the hardware's electrical capacity to accurately reproduce.

That wouldnt happen unless you really cranked it up and If the subs were in a seald box you could hear it but since they are ported to the rear you would have a very hard time distinguishing the clipping sound while in the car. I would err on the side of safety if you like the subs and switch it back to 2-8v

**edit** I checked crutchfield and its a 2v output deck so the first switch is OK but only if the gain is turned very very close to the minimum(2v spot)

[POST]

That wouldnt happen unless you really cranked it up and If the subs were in a seald box you could hear it but since they are ported to the rear you would have a very hard time distinguishing the clipping sound while in the car. I would err on the side of safety if you like the subs and switch it back to 2-8v


Oh boy... =X thanks for the note =D. saved my tush

[Eclipse99RS]

Most of the alpine decks are 2v outputs. The 05 and 06 models that are higher were the cda-9855, dva-9861 and the dva-9965. The cde-9845 is 2v.

[POST]

Most of the alpine decks are 2v outputs. The 05 and 06 models that are higher were the cda-9855, dva-9861 and the dva-9965. The cde-9845 is 2v.

so then it doesnt make a difference?

btw i bought the 45 because i do not own an ipod nor am i planning on getting one in the future, save me a couple of bucks, i actually like this headunit quite a bit. super easy to read! =D