help with buying a system..

[Tyler]

alright, i am completely new to the car audio world. i have a 240sx hatch and i want to outfit it with some new audio stuff, because right now it has no music at all in it.

i would like to have new door speakers, headunit, and a single 12" sub and amp. now when i search around for these parts i get confused on stuff like how many channels my amp needs to be and WTF are ohms? and is having 2 or 4 better?

sorry for being a complete dumba** about this but if anyone could clear up those things and possibly recommend some good brands or a setup that would work well i would greatly appriciate it!

[krimsonviper]

Until you tell us how much you're willing to spend we cant really tell you what to get. a simple saying will help you in the decision though "you get what you pay for"

since you're just trying to have one sub and one amp to power the sub, you just need a monoblock amp(1-ch amp and the preferred is a class d because its specific for a subwoofer). you can always have another amp for your fronts and rears for more clarity and a less of a chance of blowing them out during low notes. the direct definition for ohms is "electrical resistence to current", but in lamemans terms the lower the ohms(1 or 2)the harder the subwoofer is going to hit(SPL) but with the loss of SQ(sound quality).

if you want crisp highs, sweet lows, and great mids, get 2 amps: a 4-ch to power front and rear and a mono to power the sub. make the 4ch a slave to the mono(meaning you connect an RCA from the output of the mono and connect it to the 4 ch) what this does is send all of the sound the subwoofer IS NOT going to use to the slave(4ch)<---dont do this if you're going to push 2 subs or if you plan on using the cross-over(XO) in the head unit.

[Tyler]

Thank You! that helped a ton. Now im thinking i can spend about 600 on the whole thing (amp,sub,headunit) is this very realistic or not?

[PoorManQ45]

That's the exact budget I used.

I'm going to recommend speakers and a sub:

DLS RS6 two pairs at 119 per pair.TC SOunds 12" TC9 at ~$160.

Hm... This may put you about $100 over budget.

I'd put about $100 towards a HU with the features and layout that you like.

And $200 towards amps.

To save a little you could use just a pair of DLS RS5s up front an coaxials in the back

[Tyler]

sounds good! will it sound odd if i put 6.5's in the doors up front but keep the 4x6's in the back? and what about a box for my sub? what should i look for? also how many watts should my amp be?

[krimsonviper]

keep the 4x6's in the back?

you cant really tell what you have in the rear, so i'd run those til you get a spark coming from them lol

what about a box for my sub? what should i look for? also how many watts should my amp be?

zerothread/263278Your amp should have enough power to power the sub at its constant power rate(RMS)

[Tyler]

thanks a lot! this has really helped me

[Looneybomber]

since you're just trying to have one sub and one amp to power the sub, you just need a monoblock amp(1-ch amp and the preferred is a class d because its specific for a subwoofer). you can always have another amp for your fronts and rears for more clarity and a less of a chance of blowing them out during low notes. the direct definition for ohms is "electrical resistence to current", but in lamemans terms the lower the ohms(1 or 2)the harder the subwoofer is going to hit(SPL) but with the loss of SQ(sound quality).

WErrrrrr *screetching of tires*Wow, hold up, let's fix this real fast. Class D is not subwoofer specific, it just tends to be used only for subs due to the increased cost of high quality components required to make it suitable for full range use. Without getting into a profound physics based answer, of which is even outside my realm of explaining, suffice it to say, Class D amps can be used for anything so long as the manufacture specifies it.

1, 2 or 4 chan amps can be used for a single sub. It all depends on the impedence, in ohms, of the voicecoil (VC) and how many VC's it has. For example, if your speaker has a single 4ohm VC, you could take a two chan. amp, bridge it and double each channels output power, which is then combined to one. If the amp put out 100x2 at 4ohm, you will now get 400w to that one speaker. More on this later.

Ohms, power and sound quality. Two are mutually inclusive, one is has nothing to do with the other, can you tell me which one?

Let's discuss ohms. A speakers VC is wrapped in wire, of which has a certain amount of resistance. If it has a one ohm VC or dual eight ohm VC's, for all intensive purposes, it will sound exactly the same. As for power, if an amp is rated at 200w/chan at 4ohms, and you hook it up to a 2ohm speaker you should get 400w because the resistance is cut in half, so the power doubles. If the speaker is 8ohms, the resistance is doubled, so the power output by the amp gets cut in half to 100w.

As for what hits and what doesn't, it all depends on your enclosure and power available, assuming a quality sub driver is used.

*edit* fixed a couple important spelling errors, primarily a "not" to "now"
Modified by Looneybomber at 3:23 PM 7/10/2007

[Tyler]

wow looney, your the man! thanks for explaining everything in terms i could understand

[PoorManQ45]

I personally run 4 ohm subs.

I couldn't find an amp that was in my price range that put out the required power. Either 800watts at 2ohms, or two amps each putting out 400watts at 4ohms.

So what I did what bought two class A/B two channel amps. Each one when bridged puts out a claimed 800w @ 4 ohms(more likely ~500w RMS). This worked perfectly for me

I think what he was referring to about lower ohms equals lower SQ he's referring to the main speakers. Every Halving of ohms causes a doubling of distortion. Now, that may sound liek alot, but in reality it's not much distortion. It actually depends on the quality of your amplifier(s)

[krimsonviper]

Well I guess i got caught with my pants down, I kind of did stick my foot in my mouth by saying specific amp are for specific things, but in reality to a noob, they can use it as a guide book to pick up something that was built to do, what its suppose to do, not have to guess and guess wrong. Amp are pretty much universal, you just need to know how to wire things correctly to get a certain ohm load, or buy speakers with a specific ohm load to get a targeted ohm load.

I do type corrected on the whole VC's, Im young and Im still learning things, I dont presume to know everything. Therefore I didnt want to approach the subject, though I should have. I've been meaning to edit my OP by adding in "I will add things to this post as I learn them or come across to address them"

And to Q45-Thank you for backing up what I was stating. You dont really notice the difference of SQ, but it is something to keep in mind, just in case someone tries to bring down ohm load just to get a huge amount of power the sub cannot receive, therefore receiving distortion

[Looneybomber]

No problem, we're all learning. I just wanted to get the stereotypical notion of "class D is only for subs" out of the way, though to be quite honest, with the high %THD and S/N ratio's of these full range class D amps (Alpine PDX to be exact), I personally would only use them for subs. However, with as much as the PDX amps cost, it'd be a waste to spend money on them for sub duty.

As for the ohm vs distortion. I have never heard of this, or maybe I am reading it wrong. If you had a speaker with a single 8ohm VC and the same speaker, but wound with a 1ohm VC, all with the exact same TSP's in identical enclosures, with the same amount of power, you're telling me the 1ohm speaker will have 8x more distortion just because?

Now if that 1ohm speaker was receiving 8x more power too, I would agree with the increased distortion. With all things being equal though, I refuse to believe that a speakers VC will determine it's %THD

[Tyler]

alrighty!

so im gettting paid tomorrow and i stared looking for the pieces of my system.... so of course i have some questions...

first, would this be a good sub for what i wanna do? which honestly is i just wanna have some bumping bass in my 240.

http://www.cardomain.com/item/JBLGTO1204BP

second, would this amp be a good match with that sub?

http://www.cardomain.com/item/JBLCS3001

and last, if anyone has any other ideas or suggestions i am completely open to hear them... thanks again!

[krimsonviper]

to looney-IDK what THD or TSP is. its hard to notice distortion when it comes to subs, unless they're hitting past its limit. right now isnt the time i should be posting a response to this, sleepy and drunk right now, but yes you do get a "dirty" sound from the subwoofer when you cut the ohm load, its hard to explain

TJG- that amp doesnt have enough peak power, try and find an amp that get a higher peak power. chances are one with a higher warrs rms will do the trick, i would rather overpower the sub than overpower the amp, the amp costs more than the sub alot of the time

[Looneybomber]

I'm sorry. I tend to speak in accronyms.

THD = Total Harmonic Distortion.TSP = Thiel Small Parameters.

To the OP: If you want a bandpass enclosure, go for it, but I usually see a trend with people moving away from bandpass due to the increased complexity to build and the fact that all it does is boom.

[PoorManQ45]

As for the ohm vs distortion. I have never heard of this, or maybe I am reading it wrong. If you had a speaker with a single 8ohm VC and the same speaker, but wound with a 1ohm VC, all with the exact same TSP's in identical enclosures, with the same amount of power, you're telling me the 1ohm speaker will have 8x more distortion just because?

No, the amp puts out more distortion The sub just plays what it's fed within its physical limits.

[PoorManQ45]

To the OP: I personally wouldn't go with that sub and box.

I recommended a TC SOund sub for you.

Also, if you like JL Audio I have a JL 12w3V2D4 i'm looking to get rid of. $100+ shipping. It was used for about 2 weeks lightly.

[Tyler]

thanks everyone for the replies!

i will keep looking for a sub and amp that will do what i need.

i kinda liked the idea of a buying a loaded enclosure because then i know it has the correct amount of cubic feet on the inside for the sub to sound right, because eveyone says the box is the most important part.

also, for the tc sounds subs. if i was to buy one 12" tc-1000 would i want to get a single 4 ohm VC or a double 4ohm VC?

[Tyler]

ok i had another question, say if i get a sub that can handle 400 watts RMS, but i only have an amp that can push 370 watts rms. would this hurt anything if i was to run it like this?

[0wn3r]

to be honest man, you have a hatch so I would go with a 10" sub. You'll save a small bit of $ but it will be worth it for sound quality. You could also do one 5 channel amp. If you're getting a new headunit, the majority of the time you wouldn't want to stick with factory speakers. Of course, don't forget about the cost of the wires.

I used to be the ricer who spent $1300 on his Accord sound system with 2 12" Kicker Comp VR's. It was one thing after another that I was getting. Replaced the headunit...and of course the speakers sound terrible so you get speakers...and now that the speakers are kind of tinny, you want bass...and you can't have bass without an amp. And if you are getting an amp for your sub, why not for your speakers too? And now that you have all these amps, you need a cap since you already replaced your crapped-out battery.

Believe me, I learned a hard lesson that sound systems suck.

People say if you listen to rap then get a bigger sub. Again, in all honesty, one 10" (with good but not rediculous power) in a hatch sounds perfect.

[krimsonviper]

to be honest man, you have a hatch so I would go with a 10" sub. You'll save a small bit of $ but it will be worth it for sound quality. You could also do one 5 channel amp. If you're getting a new headunit, the majority of the time you wouldn't want to stick with factory speakers. Of course, don't forget about the cost of the wires.

I used to be the ricer who spent $1300 on his Accord sound system with 2 12" Kicker Comp VR's. It was one thing after another that I was getting. Replaced the headunit...and of course the speakers sound terrible so you get speakers...and now that the speakers are kind of tinny, you want bass...and you can't have bass without an amp. And if you are getting an amp for your sub, why not for your speakers too? And now that you have all these amps, you need a cap since you already replaced your crapped-out battery.

Believe me, I learned a hard lesson that sound systems suck.

People say if you listen to rap then get a bigger sub. Again, in all honesty, one 10" (with good but not rediculous power) in a hatch sounds perfect.

SO TRUE! my bro's a bit dumb thinking that you dont really need a cap unless you need like a rediculous amount of farads, but IMO any help to lessen the stress on your battery is better than nothing. i wouldnt want to be stranded somewhere w/o jumper cables

[Looneybomber]

No, the amp puts out more distortion The sub just plays what it's fed within its physical limits.

Ok, I'll agree with that. I thought we were solely talking about the driver, when in reality we were talking about the amp producing the distortion.

Game on [/wayne's world]

[PoorManQ45]

to be honest man, you have a hatch so I would go with a 10" sub.

Explain this recommendation?

SO TRUE! my bro's a bit dumb thinking that you dont really need a cap unless you need like a rediculous amount of farads, but IMO any help to lessen the stress on your battery is better than nothing. i wouldnt want to be stranded somewhere w/o jumper cables

I'd recommend an alternator upgrade to actually correct the electrical problem instead of a cap

[0wn3r]

Explain this recommendation?

sound is clearer/easier to hear with a hatch as the waves travel right over the seats as opposed to have to travel through a wall of seats.

i picture putting your sub box, in a box (trunk). you don't put your surround sound inside your entertainment center, you leave it outside of it because it sounds better.

likewise, if you open your windows, the waves travel out of the car so you need to turn the music up slightly. if you shut your windows, the waves will bounce back.

[redtop91]

That's the exact budget I used.

I'm going to recommend speakers and a sub:

DLS RS6 two pairs at 119 per pair.TC SOunds 12" TC9 at ~$160.

Hm... This may put you about $100 over budget.

I'd put about $100 towards a HU with the features and layout that you like.

And $200 towards amps.

To save a little you could use just a pair of DLS RS5s up front an coaxials in the back

Exactly the budget I was looking to spend. I <3 you.