subwoofer

[EoH 904]

i have a 97 318ic and i want to get a bass system for my car but i was wondering where is a good place to put it. I looked at bavariansoundwerks.com and they have a system that goes in the little storage thing behind the middle cushion in the back but they want like $600 for it. Any suggestions?

[Haelo]

http://i4.photobucket.com/albums/y142/haelo/garage/94BMW325IS/100_0833.jpg Mine's in the trunk

[InSepsis]

I am building one from plexiglass later today, but I still need an amp and it should be working. I want to make the box as good as possible and sounding as good as possible with it taking as little space as possible in my trunk.

[Mary99]

.... I want to make the box as good as possible and sounding as good as possible with it taking as little space as possible in my trunk....

As oppose to me and everyone else who wants the box as big and ugly as possible, extending into the cabin area and perhaps preventing my trunk from closing properly; all the whilst producing sounds that resemble dying elephants.

[Haelo]

Well, yeah. Just remember that if you bolt something to the back of the back seat and fold the seat down accidently it will rip the cords out or something horrible like that :)

[EoH 904]

well the seats dont go down, there is a cushion that you can remove in the middle that is about a foot tall and wide and behind it is an opening that goes to the wall of the trunk. i visited bevariansoundwerks.com and they have a unit that sits in this square hole (for like $600) but i guess you have to cut a hole in the trunk fabric wall b/c the pics they showed of it had it bolted to the inside of the trunk but the speaker sat in this behind cushion hole. Im thinkin it would sound better if i do it like this because its moving the air inside the cabin and not the trunk

[bboyvek]

i did what soundwerks do but instead i used a square kicker sub, and god the thing sounds good.
tomorrow nite ill post some pics if u want me to.
by the way i hooked my sub to a 900 rms kenwood amplifier

[EoH 904]

thanks, yeah i was thinkin of putting a square one in myself. and if you could post pics that would be awesome

[BMWredneck]

i did what soundwerks do but instead i used a square kicker sub, and god the thing sounds good.
tomorrow nite ill post some pics if u want me to.
by the way i hooked my sub to a 900 rms kenwood amplifier

WOuld you know what the peak ampage is?

[bboyvek]

1800 watts

[Mary99]

.....by the way i hooked my sub to a 900 rms kenwood amplifier

P = I x V therefore I = P/V
I = 900Watts/14.4V
I = 62.5 Amps

In a perfect world where your amplifier is running 100% efficient, where there is absolutely no loss of energy due to transitional loss, no loss of energy due to heat production, no loss of energy due to electrical components and thousands of other little things that eat away at your power before it can be converted to amplify a sound wave,...you would need approximately 62 amps of power from your alternator just to maintain the Root Mean Square power consumption (aka RMS or average)

In the real world where amplifiers are less than 50% efficient, unless you are one of the lucky Joes who can afford the 100K + amplifiers netting efficiency numbers in the mid 60%, than you will be requiring double the amperage to produce the 900 Watts RMS.

BMW and it's OEM partners doesn't make an alternator that will supply the car, charge the battery and leave 130 amps spare for your convenience. In fact, it's rare to find a car manufacturer that does.

[Haelo]

It's only slightly annoying to have your headlights dim every time the bass kicks.

[Mary99]

It's only slightly annoying to have your headlights dim every time the bass kicks.

Lights dimming is the visual aftermath of a larger problem......car electronics taking a voltage drop followed by a spike because of a poorly outfitted car audio.

Kind of like being kicked in the nards I guess, slightly annoying, perhaps painful, rarely causes permanent damage....prolonged though it's a different story.

There are capacitors of various sizes installed in every piece of sensitive electronic in these cars to absorb and protect from voltage drops, surges and spikes. Intentionally causing havoc to them by forcing them to perform beyond their load capacities, aka dimming lights, whilst believing this is only slightly annoying to the car's electronics is.......

I :dunno: I don't have nards for test kicking every 5 seconds or so.

[Haelo]

I was joking. it's -very- annoying to have your headlights dim every time the bass kicks :P

[bboyvek]

Lights dimming is the visual aftermath of a larger problem......car electronics taking a voltage drop followed by a spike because of a poorly outfitted car audio..

or it could be that u need a new battery... :)

"charge the battery and leave 130 amps spare for your convenience"

130 amps omg, my car only has an 80 amp alternator, and i can run everything at the same time including my kick ass subwoofer, no dimming lights or such, imagine what i can do with 130 amps!! i could install lambo doors and open them by means of a door strike..lol..

"I don't have nards for test kicking every 5 seconds or so"
dont recommend it, not a fan myself...

[djnv325i]

JL Audio 13 W7 the only way to go!

[Mary99]

Lights dimming is the visual aftermath of a larger problem......car electronics taking a voltage drop followed by a spike because of a poorly outfitted car audio......

or it could be that u need a new battery......

The role of the alternator is to supply electric power to the car, all its appliances and charge the car battery.

The role of the battery is to start the car. It operates best with a good solid discharge followed by a long slow recharge. It does not operate well with instant discharge/recharge in a frequent manner.

If the lights are dimming, it is because the alternator is inadequate for its demands. This has nothing to do with a strong or weak battery since the role of the battery was not designed to supply electricity to the car once the car is running. Although it is not uncommon for the battery to periodically supply power when the car is running to deal with unexpected surges, that isn't it's designated role. If a new battery with more capacity is required after an audio installation is performed, it is done so to extend play time after the engine and alternator are shut off.

In general, batteries supply current at a rate too slow for audio applications so capacitors (cousin of battery) are installed to handle periodic spike conditions. If a new battery appears to help with light dimming after an audio system upgrade, it is a coincidental revelation that the old battery was dying to begin with. It may appear to reduce dimming lights at first but certainly it does not address or eliminate the real problem, inadequate power from the alternator. In time, the new battery will stratify (bulge at the bottom half) because of the improper use and ultimately fail prematurely at an accelerated rate.

The more dramatic the light dim and the more frequently it occurs is directly proportional to the length of time associated with car electronics faulting, alternator failure, and battery replacement.

[Mary99]

i have a 97 318ic and i want to get a bass system for my car but i was wondering where is a good place to put it. I looked at bavariansoundwerks.com and they have a system that goes in the little storage thing behind the middle cushion in the back but they want like $600 for it. Any suggestions?

Low frequencies require distance to form the sound wave (on average 5 - 15 feet). You will notice this in a car with subs and you lean forward towards the windshield to gain that extra two feet of length. What a difference. :yikes: Having that $600 sub in the ski cubby hole isn't a bad idea except it doesn't allow for too much distance between you and the sub to really hear the low frequencies it can pump out. You hear sound before the low wave is properly formed hence you can never hear the low frequencies. Everyone outside your car will hear it, but you certainly won't. Not a very good investment if you ask me, entertain everyone except yourself. :rolleyes:

A better setup for sure is to place the subs in the trunk. This will maximize the distance between you and the subs so that you can hear the low wave after it has formed. If you are a huge bass fan and am willing to part with the spare tire, fiber glassing an enclosure in the spare tire with a false floor can house 2 x 12". That will definitely vibrate your ride.

If you don't want to lose the spare, and still would a some low end, flip the spare around and fiber glass an enclosure for an 10" sub inside the rim. That will improve the harmonics of your music but not vibrate your ride.

[TwomSixer]

Off-topic (sorry), but Mary99, since you seem to know a lot about car electronics, got a question for you.

Ever since I reset my cars computer (may be related or not, but it happened the first time I started it up after doing this), my gauges are funky. All of them. They all read to a certain point then read backwards. IE, my speedometer Goes up to 30, then goes back down. Still seems to go at the normal rate, so I can semi-judge my speed by doing some math. If I'm going faster than 30, and my speedometer is reading 15, Im actually going 45. Starts to get innacurate when it goes below zero and then starts going back up cause it seems it stays at the peg limit on the gauges for a good 8-10mph, then starts going back up again. My RPMs read up to about 1500, my fuel gauge and temp gauges go up to a qaurter. So if my fuel is reading empty and the light isnt on, I either have a half or a full tank.

Seems that all of my gauges think that a quarter way is the limit. Ive talked to all of my car-sauvy friends and they really dont have a clue. Any idea?

/done hijacking

[bboyvek]

well i still need to work on it to make it look good but these are the raw results...

[Mary99]

Off-topic (sorry), but Mary99, since you seem to know a lot about car electronics, got a question for you......../done hijacking

Like 2 help u, but start a new thread so you'll have a proper responses from entire community

:)

[TwomSixer]

Like 2 help u, but start a new thread so you'll have a proper responses from entire community

:)

I actually did include it in my "problems" thread, but didnt get any responses:

http://www.bimmerfest.com/forums/showthread.php?t=262147&highlight=TwoMSixer

Very end of my last post. I went into much more detail in this thread though.

[BMWredneck]

just upgraded to a kenwood 1800W(as in peak) 500RMS? amp. It supplies my 2 kenwood 12" 1100W(peak) subs just fine without lights dimming and such. And it sounds great compared to my old 900W(peak) amp. It hits alot harder and deeper, just like the ladies like it. haha. sorry just a little irony there. I can turn it up halfway and feel my nuts shake.

Next item on the list is to figure out where the rattle in my trunk is coming from. But it sounds great on the inside. Gotta go to the doc today cause my ears are killin me. haha.

Have fun with yalls systems, just try to do it right the first time.

Also if you experience the whole problem with your headlights dimming, buy a capacitor. It will prevent your lights dimming in most cases. But make sure you have a suitable size Nothing that will melt your amp. All it basically does is supply your amp with the power it needs when it is starved on power. (when it hits its peak wattage) Simple to install unless your the retard monkey of the group.

[Just Bryce]

just upgraded to a kenwood 1800W(as in peak) 500RMS? amp. It supplies my 2 kenwood 12" 1100W(peak) subs just fine without lights dimming and such. And it sounds great compared to my old 900W(peak) amp. It hits alot harder and deeper, just like the ladies like it. haha. sorry just a little irony there. I can turn it up halfway and feel my nuts shake.

Next item on the list is to figure out where the rattle in my trunk is coming from. But it sounds great on the inside. Gotta go to the doc today cause my ears are killin me. haha.

Have fun with yalls systems, just try to do it right the first time.

DynaMat the trunk and then add a 1farad cap and feel the bass ectension on long drops :thumbup:

[BMWredneck]

Where would i put this dynamat though? Would i have to take out my current insulation?

I cant afford the cap yet, but it might be in the werks later on. I still plan on upgrading the amp and subs when i get tired of this. But thats like a 3000W amp too... itll be nice:)

[Just Bryce]

This is what you want to go for, I know Tommy and this truck is INSANE !!!!!

http://www.youtube.com/watch?v=OStXTxZxd1Y