BF2S Forums Car Audio

Never heard of Infinity, but the rear speakers and the Subs looks good.
The amp is a good choice as well.

Crutchfield is a good place to start, showing you exactly what size speakers your car requires, and if you buy a deck from them, they include tools and a wiring harness to plug into your factory one. (just advice for beginners)  Alpine makes very good decks, and you can't really go wrong with one. 

If your door speakers are decent, can play at high volume without distortion, I would leave them alone and focus on the deck and an amp/sub setup.

I have junk 5 1/4's in the front doors and back hatch of a jeep, with a crappy deck.  But my MTX thunder running 2 JL Audio 12'' subs in a bandpass box absolutely pounds, and you can't hear the crappiness of my door speakers over them.  Get some bass blockers to put in-line with those and you should be fine.  Also, bandpass sucks in my opinion, get a decent ported box from a local audio shop, a guy quoted me about 100-129 for a decent one, and I agree - 10X better.

Also don't bother with an alarm.  Detach the faceplate when you're not there, because any decent thief will either disable your alarm or just fuckin smash your window, rip out your shit and be gone in 30 seconds.

This is all speaking from personal experience, but if you have some extra grip, I'd go with some Infinity kappas for the doors.  Good luck.

Edit:  just saw the post above for those JL W7's.  If you're Mark Cuban, go ahead and get those, but for those on a budget (like me), the cheapest JL Audio subwoofer (the W0) are around a hundred bucks apiece and to the untrained ear will sound better than any other similar-spec sub.

Last edited by HaywoodJablowme (2007-04-21 12:03:17)

ThomasMorgan wrote:

sithao wrote:

Wont disappoint you if you can afford one of these suckers. Also you're better off going to your local audio shop then going to a store like Bestbuy.

http://mobile.jlaudio.com/products_subs … ?page_id=3

Thanks, but as far as I know, I don't have a local audio shop.

Plus, Best Buy has free installation...which I need...since I have no clue how to even start installing this stuff.

Seriously, when I was just starting out like you, I just bought a cheap deck off sony, they had all the schematics and step-by step, with harnesses.  Save yourself 50 bucks and do it that way.  Don't waste your money at Best Buy.  Plus crutchfield has a good selection of Alpine's and their customer service is top-notch.  Honest to god it will take you 30 minutes or less to swap a deck.  Super easy.  The hardest part will be the dash trim, but still a piece of cake.

And if you live in Chicago, there are a shitload of local car stereo shops.  I lived on the southside, and there's a bunch on Harlem.

Nice setup, What kind of car is that system in?.

I would keep the same head unit since Nickleback is still in heavy rotation, therefore you will not to supply your own.

The link to the CD Deck did not work, which is it?

Since I've got a free minute, I figure I'll elaborate a little on the ohm ratings/impedence/resistance issue....as it is very important to car audio and I feel that everyone who wants a nice system aught to have a basic knowledge.

A speaker is a resistor.  Sending an audio signal to a speaker requires power (from the amp) and the speaker, depending on its rated resistance will limit the AMOUNT of power that can pass through it.  Think of it as a door to a busy supermarket.  There's a lot of people outside that want to get inside (power), but the door is only so big (resistance)....it can only let so many people (power) through at one time.

So, in simple terms, a speaker's resistance (given in the measurement of OHMS, ie, 2 or 4 or 8 ohms) will essentially determine the power of your amp.  A lower resistance speaker will be putting out more watts than a higher resistance speaker all else being equal.

But, we have to take into account the power ratings of your amp.  MOST amps are rated to produce the highest wattage at 2 ohms per channel (ie, per speaker hookup).  So, if you hook up a 4 ohm speaker, you cut your wattage in half.  So for instance, you have a two channel amp (so it has two speaker hookups) and it is 1200 watts total, 600 per channel at 2 ohms per channel.  If you get two 4 ohm speakers and hook one up to each speaker input, each speaker will only utilize half that (300 watts per channel, so only 600 watts total).  That is leaving a lot of potential power from your amp untapped.  So, in this case, you'd want to get two 2 ohm speakers to get the fully rated power. 

Now, if you offer LESS resistance than what the amp recommends, then you run the risk of frying your amp, because now you are drawing even MORE POWER from your amp than it is rated to produce at a stable level.  For instance, your amp is rated to produce its max stable power at 2 ohms per channel, and you give it 1 ohm per channel.  Expect your amp to go up in smoke.

That seems fairly straighforward, but it gets more confusing when we are talking about different speaker combos and different types of amp, etc.  For instance, let's say you have a single channel amp (ie, it has only a single speaker hookup), and this amp is rated to put out its max stable power at 4ohm from that one channel.  BUT...you want to run TWO speakers off this single channel amp.  It can be done, but you have to apply a little physics to make sure it is done right.  We now have to BRIDGE the speakers/amp so that we achieve the proper resistance for the amp.  This means that basically, we are connecting TWO speakers to a single channel (speaker hookup).

There are TWO ways to do this: in series, and in parralel.  Let's go back to the "door to a busy supermarket" analogy.  You want to get those people in and out quicker.  What happens if you put one door in front of the other (ie, you must walk through one set of doors, and then another to get in/out)?  You INCREASE the resistance and slow down the flow of people (power)....this is equivalent to bridging two speakers in SERIES.  If you place the doors side by side, then people can go through either set of doors and eneter/exit faster, because you have lowered the resistance.....this is equivalent to bridging two speakers in PARRALLEL.

That's all well and good, but how do you figure out what your total resistance is going to be when bridging to speakers?

There are simple formulas for both parralel and series applications.

For series, it is simple addition:  R(total) = R1 + R2 .....etc  (so the total resistance equals the resistance of all speakers in the series added together, so two 2 ohm speakers in series produce a total resistance of 4 ohms).

For parrallel, it's a tad more complicated, but nothing major:  1/R(total) = 1/R1 + 1/R2 .....etc.  So, if you run two 4 ohm speakers in parrallel, you get a total resistance of 2 ohm.

So back to that hypothetical of hooking up two subs to a single channel amp rated to produce max stable power at 4 ohms for that channel.  How would we want to run our subs, and what resistance would we want?  From the examples above, we know that two 2 ohm subs run in series would give us what we want (4 ohms total).  So, we would buy our speakers accordingly.

But what does it mean to run speakers in series versus parralel.  For a series application, you'd have the negative lead of ONE speaker attached to the negative input on the amp, then you'd attach to positive lead of the same speaker to the negative lead of the SECOND speaker.  You'd finish it off by connecting the positive lead of the second speaker to the positive input of the amp.

For parralel wiring, you'd attach both negative leads from both speakers to the negative input on the amp, and then both positive leads from both speakers to the positive input.

Here's a graphical representation:


Now here's where it gets EVEN TRICKIER.  The speakers you posted are DUAL VOICE COIL speakers....that means, instead of each speaker being a single resistor, each speaker is actually TWO resistors in one.  That means that the individual voice coils of the speakers can be bridged in either series or parralel to produce a single resistor of different resistances.

For example, you posted dual voice coil speakers that are 4 ohms PER voice coil.  So, each voice coil could be bridged in series, producing a speaker that is a total of 8 ohms of resistance.  Or, each voice coil could be bridged in parrallel to produce a speaker that is a total of 2 ohms of resistance. 

Continuing with the products you posted as examples, if you want to get the maximum power out of your amp, you'd get two of these speakers, and bridge the voice coils in parrallel so that each speaker was a total of 2 ohms.  That way, you get the maximum power per channel from your amp (600 watts to each speaker).
This taken from the specs on the amp you posted:
Max Power Watts per Channel (4 Ohms)     300 x 2
Max Power Watts per Channel (2 Ohms)     600 x 2
Max Power Watts per Channel (4 Ohms Bridged)     1200

What happens if you run each in series?  Well, you get 8 ohms of resistance per speaker/amp channel....and you get nowhere near the maximum power from your amp. 

That's confusing enough for now......I won't get into multiple channel, multiple speaker combos (ie, if you wanted to run 3 subs off a 2 channel amp).

Anyway...hopefully you were able to at least begin to grasp the concept of resistance and its importance to proper car audio install and performance after this novel of a post.

KiL

Last edited by FeedUsYourFetus (2007-04-23 13:24:42)

I have two Infinity kappa perfect 10's in the back of my car, and i love it. They are being pushed by an MTX amp, and controlled by a Kenwood head unit, which is also of very good quality.


If you are getting subs in the back, try to pick a deck that has a high voltage subwoofer output. The higher the voltage, the cleaner the signal, the better the sound. Generally speaking, 5 V is a good number.

Also, if you want your bass to hit precise, make sure you get the subs put in a sealed box. I have that set up. I listen to lots of fast beats, and my subs keep right up and don't get muddy like a ported box would offer. Conversely, a ported box will give you much louder bass, but as i mentioned, can get a bit muddy when a lot is going on. A band pass box is a bit of a combination of the two.

Hope this was a bit helpful, but you really want to listen to Feedusyourfetus, he knows his shit, much more than me.

heggs wrote:

you really want to listen to Feedusyourfetus, he knows his shit, much more than me.

Thankee.

Just a quick (not really) bit on boxes....elaborating on what heggs posted (but I won't get into bandpass boxes).

There are "essentially" two box designs (some will argue there are more, but whatever, these are the two main staples of box designs): sealed and ported.  Each has its place, and what you choose will be determined by the speaker you choose (sometimes, ie some speakers are designed to utilized a sealed enclosure, and some designed to utilize a ported, and some designed to be more versatile), and the application you are going for.

The meat and potatoes of it is this:

A sealed enclosure is smaller, and usually results in tighter, cleaner bass that is more versatile when it comes to a variety of applications and the smaller box makes install easier without giving up too much room.  Often, people who just want some bass but not to have their guts liquified opt for the sealed enclosure (ie, you listen to all kinds of music, but still like some kick to it).

A ported enclosure is typically much bigger, and results in very powerful, boomy bass, often more suited for songs that focus on deep baselines (ie, you love gangsta rap).  The other application is SPL competitions where the object of the game is to produce the most and loudest bass possible.....but that's not relevant here.

What is the physical design difference of the two?  Well, a sealed enclosure is exactly that......sealed.  There are no ports or any access for air to escape the inside of the box.  This prevents the cone of the speaker from  over excursion (ie, the negative pressure behind the speaker prevents it from protruding out TOO much while hitting a bass line).  This is basically why the sound is snappier, cleaner......but less boomy.

A ported enclosure utilizes a tuned port (more on what tuned means in a sec) to maximize the air displacement of the speaker (ie, the front of the speaker displaces air, and so does the back, through the port).  This typically requires a lot more internal airspace for the box to maximize the effectiveness of the enclosure.

So what does "tuned mean"?  Well, a speaker emits sound waves from both the front AND back of the speaker.  The sound waves emitted out the back of a speaker are usually negated in a sealed enclosure....they are aborbed by the inside of the box and for the most part don't leave.

The idea of a ported enclosure is to utilize these sound waves (and the air displacement created by the rear of the speaker).  However, sound waves are a crazy thing.......they can help each other or hurt each other.  A sound wave can either amplify another, or cancel it out/distort it.  The idea of tuning a port on a ported box is to ensure that the soundwaves coming out of the port compliment and amplify the sound waves coming out the front of the speaker.  An improperly designed ported enclosure can distort your sound, and lead to a really piss poor listening experience w/ terrible bass.

KiL

Last edited by FeedUsYourFetus (2007-04-24 07:43:38)

I'm gonna give a rundown of my system just to give a real life example of setup.

First off, box choice:  I went w/ a sealed enclosure because I listen to a variety of music first off, and second of all I have a very small car w/ very small "trunk space" (Scion XB, see pics posted earlier).  Oh, that and, a sealed enclsosure is much easier to build properly.

Components:
AMP:  Rockfor Power 800a2 2 channel amp rated at a max power of 950 wats w/ max power at 2 ohms per channel.
Subs:  Two Kicker L7 Solobaric dual voice coil subs (4ohm per voice coil).
Capacitor:  Lightning Audio 1 farad cap (why this one?  it was FREE from a friend, can't go wron't there).
Wiring kit (yes, important too):  Scoche kit from Walmart....surprisingly high quality.  The power cable was 0 guage (bit and fat like I wanted), and it came w/ a big fuse to go between amp and battery (you want this too....better to fry a fuse than an amp).

Anyway, did all the wiring myself.  The annoying part came because I used the stock deck, which doesn't have amp outputs, so I had to tap into the rear speaker outputs to set up an RCA adapter so I could send a signal to the samp.

But anyway.......I digress.  Remember I have a two channel amp that puts out max power at 2 ohms and I have two dual voice coil subs (4 ohms per coil).

So, of course I bridged each individual subs voice coils in parallel so that the total resistance for each sub was 2 ohms.  This way, I could hook each sub up to each channel and get MAX power output from each sub.

Why this post?  So I could give a real world example of how this is done.

Now, is this the ONLY way I could have done it?

NO.  Remember, most dual channel amps can be run in stereo (you hook each speaker up to each channel....simplest).....OR mono mode (you bridge the speakers and then hook BOTH speakers up to BOTH channels....so for instance, both speakers are hooked to the negative hookup of one channel, and both speakers are hooked to the positive lead of the second channel....this leaves two hookups on the amp without a speaker attached to them).  Now, when an amp is bridged in MONO across two channels, the lowest stable ohm rating bridge is double the individual channels (so if my amp was stable down to 2 ohms per channel in stereo mode, if I bridge it in a MONO application the stable ohm rating for both channels combined is 4 ohms.......still with me?).

So, I COULD have set up my speakers/amp differently.  If I wanted to bridge the amp/speakers I could have bridged each voice coil in series (giving me two 8 ohm subs).  Then, i could bridge the speakers together in parallel giving me a total resistance of 4 ohms and run the speakers in MONO mode bridging the amps channels together (ie, I hook both lead from both speakers to the negative input of ONE speaker channel, and then both positive leads of both speakers to the positive input).  This would give me the same overall power output.

Why didn't I do this?  Dunno......simplicity.  And the other fact is that if you have two subs in sterio running individually off the amp, versus two subs bridged in mono..........you're not gonna notice a difference (as far as I know, there is no benefit to one over the other).

KiL

ThomasMorgan wrote:

http://img.mercadolibre.com.pe/jm/img?s … pg&v=P

...eh?

Those there decibels be in yo trunk shattering yo windowz.

Marlboroman82 wrote:

omg sensory over load. also look on ebay you can sometimes score some great deals. where i bought all my stuff. polk momo's for half the price of what you pay at a store.

Rgr that.......I got BOTH my subs (brand new) AND the box for $300 on ebay.  That's saying something because at the time an individual 12" Kicker L7 was going for about $300 from retailers.

However, a few days later......the person I bought from had his account deleted.  I don't know what to make of that (hot merchandise?  God I hope not!).  However, I actually think his account was deletd because Kicker is VERY strict about "authentic retailers" and don't look kindly on others selling their products new.  At least that's what I tell myself so I don't have this nagging feeling that my subs were jacked from someone.  BUt......they did come newly packaged in full retail boxes, so if they stole em, the stole em new.....and not from someone's trunk.

KiL

ZOMG.......i make all teh posts in this threads.

KiL