noob audio Q's

[PaulPDX]

Also please invest in a good active crossover (3 way) that can be set for front rear and sub

Not necessary if he is using a two amp set up. Most amps come with x-overs.

 

[Attack Eagle]

yes they do, but the points are set points and usually not exactly what you end up needing.

Coustics had gain controls in addition to adjustable crossover points.

as opposed to having to dig out the amp to get to the controls, or finding that you need something inbetween or even above or below the settings on the amp itself.

when running stereo I would have an adjustable xover set the low pass on the amps to the lowest setting (too low) and on the sub amp set the high pass too high and use the crossover to set up the system.

generally amps don't have aggressive enough slopes on the built in xovers, generally 6-12 dB per octave, and with mixed speaker types and ratings like he has I believe the adjustability will be very beneficial (plus the bass gain knob is great for adjusting between radio /cd or various forms of music). Not every amp has this feature, and at less than $100 dollars sometimes less than $50 it is very beneficial for getting everything set/leveled correctly. at least in my opinion.

 

[theycallmebruce]

my head unit comes with 4v high/low/sub pre-outs.
I was just gonna run the sub pre-outs to an amp to a sub and leave the other speakers alone for now.
I'm not sure what the crossover points are, but gonna give that a try first. if it fills the void and the quality of the audio is decent enough, i might stop there.

i'm probably gonna go with the kicker 10" preloaded enclosure i posted a link to above.

the whole ohm/load/bridged thing is confusing. i'll have to look that up some.

as far as 4 gauge wiring, that's for the amp to the battery? do i need to use that to the speakers too? (if i decide to amp the rest of the system later on)

i'm gonna have to find out how to wire up an amp too. is it just straight wire from the battery with a fuse inline?

 

[PaulPDX]

Well, what can I say. I've had several systems with or without add-on x-overs over the years, and the ones with out did just fine using the x-overs of the amps. Bruce isn't going to enter his car in hi-fi competitions and really isn't into the ICE stuff to be able to discern the difference (probably?)... given that, the extra $50 to $100, as affordable as that is, is still extra $50 to $100 he doesn't absolutely have to spend.

Bruce... if you plan on adding another amp to power the speakers... do this:

Run 4 gauge power from battery (make sure you install an inline fuse near the battery-amp install kits come with this fuse and fuseholder) to wherever you want to mount the amp(s), cut the cable to length and install a distribution block (like this one: http://www.cardomain.com/item/LITBD1X2, 4 gauge in 8 gauge out to amp +12v). The dist block will handle power and ground per block. For now, until you get another amp, you can ground the sub amp directly to a good ground in the chassis.

Powering speakers w/deck is good enough for now. And yes...use the decks sub preout to send signal to the sub amp.

 

[Redmachine]

Well, what can I say. I've had several systems with or without add-on x-overs over the years, and the ones with out did just fine using the x-overs of the amps. Bruce isn't going to enter his car in hi-fi competitions and really isn't into the ICE stuff to be able to discern the difference (probably?)... given that, the extra $50 to $100, as affordable as that is, is still extra $50 to $100 he doesn't absolutely have to spend.

Bruce... if you plan on adding another amp to power the speakers... do this:

Run 4 gauge power from battery (make sure you install an inline fuse near the battery-amp install kits come with this fuse and fuseholder) to wherever you want to mount the amp(s), cut the cable to length and install a distribution block (like this one: http://www.cardomain.com/item/LITBD1X2, 4 gauge in 8 gauge out to amp +12v). The dist block will handle power and ground per block. For now, until you get another amp, you can ground the sub amp directly to a good ground in the chassis.

Powering speakers w/deck is good enough for now. And yes...use the decks sub preout to send signal to the sub amp.

Good choices, I went with the schoches 4 guage kit from walmart, has a 100amp inline fuse and a nice goldplated distr. block for up to 3 additional amps, its no stinger but works good. My wife went with a stinger 0/1 guage and it really sucks down the power.

 

[theycallmebruce]

amp:
http://www.cardomain.com/item/SONXMD500X

woofer/enclosure:
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=13326
OR
http://www.cardomain.com/item/KIC03TC10

the amp i chose will hit the max rating at 4 ohms for the kicker. according to http://www.polkaudio.com/car/faqad/advice.php?article=powerup that's a good thing? if that's the case, will it be too weak for the MTX? about the same price, which should i choose?

don't want to blow a load on this, but get the best bang for the buck (no pun intended).

 

[theycallmebruce]

actually, this looks like a better amp for the money:
http://www.acaraudio.com/product_info.php?products_id=303

 

[PaulPDX]

Re-read my reponses on the amp and power rating. Already answered your questions.

 

[theycallmebruce]

gotcha. better overdrive than underdrive.

not necessary to get a 4 ohm sub since it'll be powered seperately from the rest of the system correct?

will actually drain less power if i get lower resistance?
more efficient at the expense of a little barely noticable noise?

 

[Attack Eagle]

General rule of thumb. stereo amps have to run a 4ohm load, mono amps can run a 2 ohm load.


you can either do a sub with two 4 ohm voice coils (wire + to + and neg to neg to get 2 ohms), or a sub with just one 2 ohm voice coil.
since the amp you were looking at produces 500W into 2 ohms and is a mono amp
a class D is the way to go as it draws less amps than a regular amp.

I am only hesitant about xplod just cause they tend to live up to their name...
unlike ES, they aren't really highend stuff, more like entry level/inexpensive?

I have been doing Kicker comp VRs for about 130 and boxes for about 40-50 at the shop I work at.


Have you tried checking with a local specialist? If you are buying several items they will generally work with you on the price some...

Remember that items purchased over the internet are generally not warrantied by the manufacturer (unless the dealer is an authorized internet dealer)... thus my hesitancy on the xploding amp.

my old kickers only had a 70 and 125 hz option which was not enough for what I was doing, and neigther did my old fosgate an alpine amps.

I defer to my peers judgement that you probably don't need one now... internal xovers have gotten a lot better in the last 2-3 years

 

[PaulPDX]

not necessary to get a 4 ohm sub since it'll be powered seperately from the rest of the system correct

No. Most speakers come with 4 ohm resistance. It's when you wire up a pair in parallel, they become 2 ohm resistance. If you wire them in series, they become 8 ohm. Running a pair of subs or a dual voice coil sub at 2 ohm with a 2 ohm stable amp means you can spend X dollar and get twice the power out of the amp at the expense of amp heat, and noise.

For now, just buy yourself a 4 ohm single voice coil sub, and a 4 ohm stable amp and call it good. Later, do some leg work on your own and research on the web and read about dual voice subs and basic electronics. Crutchfield.com, mentioned very early on in this thread contains lots of helpful FAQs. If you had gone there as advised, you'd be less confused.

will actually drain less power if i get lower resistance?

Less resistance means more current draw not less. Just stick with 4 ohm. Lower resistance also means higher current flow = more heat, which means larger gauge cable. Too high of a current draw can melt wires together. 4 gauge cable is fine for your application. Period.

 

[theycallmebruce]

thanks guys and sorry for being a pain in the ass. i do search and read what i can. it's just that sometimes getting some questions answered for clarification will spark some light bulbs and point me in the right direction of what to search for to read about. also, sometimes inside advice from 'real-life' experts is more useful than reading articles directed at a more general audience. so thanks again for the help and i'll try and keep the 'lazy' questions to a minimum

i've come to a decision on the woofer/box to get and will get an amp to match. since i hate having to continuously remove and replace the damn plastic panels, i might just get an amp for the 6 speakers as well and do it all at once. if this proves too much, i might just get it professionally installed. haven't decided yet.

woofer/box:
Kicker Comp HC12
amp:
undecided - class D amp between 150 and 300 watts RMS @ 4 ohms

amp for speakers:
undecided minimum 75x4 @ 4 ohm

http://www.crutchfieldadvisor.com/S-eiadL7muQRP/learningcenter/car/amplifiers_wiring.html

what does the capacitor do in the diagram and do i need it?
EDIT: nevermind. i clicked on the link below it and read. seems like it's a sort of mini-battery. doesn't look like it would hurt to have one, depending on cost.

the link paulpdx gave me http://www.cardomain.com/item/LITBD1X2
that device includes the distribution and ground block and i don't need seperate ones like in the diagram?

i understand i'll be wiring a bit differently (amps won't be in sequence like in the photo as i have 3 sets of pre-outs and won't need to pass signal from one amp to another).

speaker wire: i want to upgrade the wire while i'm in there. i'm assuming i can get the correct size spade connectors to attach to different wires. they looked pretty standard on all the speakers i've installed so far (one fat and one skinny). are these the 5-way binding posts? should i be concerned about the material these connectors are constructed from? i'm assuming 16ga speaker wire should be good enough for my proposed setup? if i'm planning on setting up the amps in the trunk, should i get thicker gauge due to power loss over distance?
i also understand that speaker wire and power wire to amp should not run in parallel if possible to minimize noise.

woofer and amp mounting: what are the best ways to secure these in the trunk?

i'll probably try and dynamat some as well. probably mostly in the trunk and the area behind the panels in the rear seats.

those crutchfield videos are awesome!

 

[PaulPDX]

thanks guys and sorry for being a pain in the ass. i do search and read what i can. it's just that sometimes getting some questions answered for clarification will spark some light bulbs and point me in the right direction of what to search for to read about. also, sometimes inside advice from 'real-life' experts is more useful than reading articles directed at a more general audience. so thanks again for the help and i'll try and keep the 'lazy' questions to a minimum

All lot of the questions can be answered by calling Crutchfield too. You don't have to buy stuff to ask them questions. The sales reps are very friendly (they have to be, that's their brand... it's what their entire business is built on).

Years ago I learned alot just by chatting with them and going to the local shop and bs'ing with the sales people and installers. Eventually made friends with some installers and learned even more. So do some leg work. You'll learn a lot more than asking people to spoonfeed you info, wipe your chin, dot your "i"s and cross your "t"s. No offense intended. Honestly, it's the best way to learn about this stuff.

the link paulpdx gave me http://www.cardomain.com/item/LITBD1X2
that device includes the distribution and ground block and i don't need seperate ones like in the diagram?

Yes... the one I used as an example has two blocks in one plastic housing. One side for ground the other for power. You don't have to use it. You can use a single block for just the power and ground directly out from the amps to the nearest ground like an existing bolt in in floor or metal panels in the car (this may be the best route since it's optimal to have as short of a ground wire as possible). Absolutely use a meter or test light probe to test your possible ground points to make sure they are good grounds.

If you are not pushing a lot of power with your amps and you have a decent alternator in the car (90 amps and up) you don't really need a cap. A cap is basically like a reserve battery. It charges up and holds the charge at a steady rate and can discharge quickly when the amp demands it (like a big bass hit). The cap eases strain on the car's electrical system. It's optional, not required. I usually use one. A full farad is not neccessary unless you are running a lot of power. Half farad cap is half the size, easier to install and conceal behind interior panels and is good enough for normal use.

Stock speaker wires are fine in the front. It's much easier to totally upgrade the wires for the rear speakers. Too much of a pain to run new wires through the dash through the door loom and into the doors. Overkill.

You should always try to keep power and ground wires as far apart from your RCA cables and speaker wires as much as possible. HOWEVER, good quality RCAs and speaker wires are shielded well enough where you don't really have to be paranoid about them picking up noise from the power cables. Have good grounds is much more crucial in respect to engine/ground loop noise. Seat belt anchor bolts and seat rail bolts can usually provide good grounds.

woofer and amp mounting: what are the best ways to secure these in the trunk?

Sheet metal screw if you are not paranoid about putting holes in a car. I am. I would build a false floor with wood and hide your audio gear under it. Make sure there is at least 1" of airspace all around the amp(s). You don't want the amps to overheat and fry. You can then secure the sub to the false floor with metal cabinetry brackets (Home Depot, Lowe's) or tie down straps... or even velcro.

i'll probably try and dynamat some as well. probably mostly in the trunk and the area behind the panels in the rear seats.

Good idea. One other thing most people forget... get some of those little clear round rubber stick-on appliance/furniature feets at Lowe's or Home Depot and stick them on the back of your license plate at the corners then bolt the plate back on as you normally would. Most people don't realize that most of the rattling comes for their license plate.

One last tip about speaker wires... to make installation easy... assuming you already got a harness adapter to mate your aftermarket deck to the factory radio harness...

The adapter is already labeled... so cut the speaker output wires and solder and heat shrink on your new speaker wires. That way you don't have to go through the trouble of running wires to the speakers.

1) install your RCA cables to the deck preouts and the amp inputs.
2) cut the speaker output wires on the adapter harness between the deck and the plug (leaving the stock plug and harness unaltered)
3) lay out new speaker wires to go from the amps' speaker outputs to the back of the deck
4) connect your new wires to the wires on the harness you had just cut with solder and heat shrink... to the harness side... not the deck side. You're feeding signal from the amp to the speakers.
5) mark and lable the wires Front Left, Front Right, etc.. as you go to make life easier. If you get mixed up... a trick is to touch the speaker wire pairs (+/-) to the ends of a AA battery. This will generate static with whichever speaker you've got the wires for.
6) finish wiring up the amps and you're done.

 

[theycallmebruce]

thanks for the tip. i've already run wire from the headunit side of the harness to the crossovers under my passenger seat when i installed the component set and 6x9s. i'll probably wind up just cutting the speaker level source from the headunit and just running a new source from the amp to the crossovers. i took out the stock amp and connected to the speaker outputs from the stock amp harness.

if i have high-pass and low-pass pre-amp output from the headunit and i don't have either filter on, i can use either RCA set to source the amp correct? they should both run full range if the filters are off?

i think i have what i need to know to get this thing set up (thanks mainly to paulpdx, attack eagle, and countless hours of google and crutchfield.com). just a matter of getting the parts, some planning of fine details and the actual work.

thanks for the suggestion of the false floor. i don't know if i'll have the patience for it, but i'll at least lay down 1 piece of wood the shape of the trunk and carpet it and mount the stuff to that. don't think i'll go with the second piece over it for concealment. on that note, since i'll need to build anyway, i'm toying with the idea of constructing a sub box myself. i've done some reading on it and i think i can handle it. this way i can shape it how i want and stuff it if i choose.

it'll be a few weeks at least till i get everything worked out. i'll try and get as many pics of the install as i can. maybe throw together some kind of tech article so someone like me doesn't come along and start another one of these ridiculously long threads again =P

thanks again for the help guys. i'll definitely do some leg work and probably hit a car audio installation place this weekend and take a look at some work and talk to some people

 

[PaulPDX]

if i have high-pass and low-pass pre-amp output from the headunit and i don't have either filter on, i can use either RCA set to source the amp correct? they should both run full range if the filters are off?

I am a little confused by your question. If the headunit does not have x-over features, they are full range front and rear pre-outs + sub preout. Use RCAs to spend signal to the amps. The amps have x-overs. Since your front speakers have their own x-overs... you can set the speaker amp to full range. You'll want to set your low pass x-over on the sub amp and tune the cutoff freq. point to your liking.

thanks for the suggestion of the false floor. i don't know if i'll have the patience for it, but i'll at least lay down 1 piece of wood the shape of the trunk and carpet it and mount the stuff to that. don't think i'll go with the second piece over it for concealment. on that note, since i'll need to build anyway, i'm toying with the idea of constructing a sub box myself. i've done some reading on it and i think i can handle it. this way i can shape it how i want and stuff it if i choose.

Why would it be too hard to make another floor? You're making one already... the upper one is just a duplicate of the lower one with perhaps some trimming on the edges. Just screw in some blocks of wood inbetween as spacers to create room for the amps, carpet the top floor and you're done. It doesn't have to be fancy. The false floor isn't just for concealment. There is practical purpose too. It allows you to carry cargo without having the amps get in the way... and keep the amps nice... keep wires out of the way and avoid snagging on cargo and causing shorts.

 

[theycallmebruce]

my bad on the pre-out question. you are right. they are front/rear/sub. i guess i use the front for 2 channels and the rear for the other 2. they should be the same range of output though so i guess using both is for purposes of fading or imaging? my headunit has this 'dynamic sound organizer' with 3 settings. the higher the setting, the more the music seems to come from the front of the car. it also gets crisper as well, but at the highest setting, the pitch gets really high and you lose a lot of bass.

my concern with the second level of the false floor is that i'll lose another 2 or 3 inches of height for trunk space for the entire area of the trunk. maybe i'll build a partial 2nd floor, just enough to cover the amps and associated hardware. i'm aiming to keep whatever i can as close to the rear seats as possible. what about mounting the amps on the woofer box? is that advisable if i keep everything sealed properly?

on the installs i've seen, holes are cut out of the second floor to expose the top of the amp, i'm assuming for cooling purposes. is this the common way to go or do people cover it up entirely?

still tossing around ideas...

 

[Attack Eagle]

if you aren't sure whether or not you are going to add the f/r speaker amp yet...

run 4ga to the "trunk" and run all 3 sets of rcas... then you don't have to pull the covers again. You can use a simple distribution fuse block for the power and just a distribution block for the grounds... when you want another amp, everything is there except power and ground 8ga. which will go to the distribution blocks.

I got some electrical tape in 4 colors for $1 at the local dollar store... I use one color one the front rcas before i install them. just a loop front and rear, another color for the rears and a third for the sub (I don't use the red color). I use yellow front green rear and blue sub, ie the rainbow order and the order ofthe speakers front to rear.

When I connect the rcas to the head I use the same color tape to pass a loop around the joined rcas so no matter what the shell can't ground and they don't come loose. If I ever need to test anything I don't have to refer to the head's manual or pull the head all the way out to know which set of rcas I am looking at.

Don't screw an amplifier to metal... it can cause a ground loop if your ground is not up to par in the rear or at the battery. mount to wood instead.