Hello,
I know we have lots of audio experts so i though i'd ask here.
The SUV is a 2001 nissan xterra with a stock 6 CD changer and 6 speakers(two of those being the tweeters up front.)  The front speakers are 6.5'' front and  are 6X9''rear .  I cannot find reliable info but the max output from the stock 2001 6 cd changer receivers is 100 or 180 watts. which will be close to 45X4? maybe.

The sound system is very weak and has little bass to it. I read that this was common with 2000 and 2001 Xterras  which had later upgraded their systems and speakers.  Some folks have even said that just upgrading the speakers helped.  Im wondrering how much of a difference would it make just to upgrade those.

Say i do decide to upgrade just the speakers to some higher output ones. like those rated at 40watts min and 220watts max for the front 6.5''s and a similiar deal for the rear 6x9's.  Will the stock stereo/cd changer have trouble powering those speakers up?

Now say i got a 4 channel amp to increase the power(lets say a 400-500watt amp).  And get upgraded 6.5''s front and 6x9''s rear. would i only get high sound and not bass or will the bass be improved too?  also would i have to upgrade tweeters with the extra watts added.  
Will a sub and seperate amp be needed to balance it all out? like say a 300 watt sub and amp.  

Are there any 5 or 6 channel amps designed for 4 speakers and a sub? just to have it all in one amp.  Scratch that. just saw the prices on 5 and 6 channel amps. I noticed that some of the newer Xterra models(2003s) had a sub enclosure built in the back area. So if i did go with that i'd probably check junk yards and pull one out just so it will fit on the side of the rear area and be low profile.  The custom fiberglass thing looks like a pain in the ass to do. Plus i dont know much about it like how to mount it .

Being that the stock system has tweeters, i guess it must have cross overs too? Would i need to upgrade those maybe?  and RMS watts is normal hearing volume level as opposed to max output ratings that are the max right?  since this system is maybe 4x45watt it operantes normally in about 24 or so regularly? so adding 50watt min 220watt max speakers will probably not be a good idea?  Im not sure.   Im not looking into a crazy ass dual sub system, Just something much better than the crappy sound that it has now. Let me know what im doing wrong here.
Share your ideas on this.   Edited to add. i want to keep the 6 CD changer so ill try and avoid getting a different head unit for this.
Thanks in advance.

I had a '01  P/U with the same setup,
You can add anything you like to that stock changer.
Replace all the speakers and a add an amp ( I got two in the EE BTW)
On subs that depends on what you want to listen to / spend.
10's are a bit better for rock and roll and some country, where 12's are more for hip hop ( JMO).

I would 86 the stock speakers, they suck

Make it real easy.

Upgrade the fron 6.5's with the best you can afford, Tear out the rears and forgetaboutit. Buy a 2 channel amp that gives good power in line with what the 6.5'2 are rated at.
As a side note, I prefer to overpower my mids and highs as much as possible. DONT do this unless your knowledgable on what your doing. I like about 2-300 watts per side for mids and highs, I recommend you buy an amp rated to the speakers.

Get a good 12 or 15" sub with a amp for it.

2 components, 1 sub, 2 amps.

To address your specific questions....

Quoted: The SUV is a 2001 nissan xterra with a stock 6 CD changer and 6 speakers(two of those being the tweeters up front.)  The front speakers are 6.5'' front and  are 6X9''rear .  I cannot find reliable info but the max output from the stock 2001 6 cd changer receivers is 100 or 180 watts. which will be close to 45X4? maybe.

Dont worry about it. Stock recievers are always way the hell overrated. From your reciever I'd guess 10 to 15 watts give or take.

The sound system is very weak and has little bass to it. I read that this was common with 2000 and 2001 Xterras  which had later upgraded their systems and speakers.  Some folks have even said that just upgrading the speakers helped.  Im wondrering how much of a difference would it make just to upgrade those.

Speakers are the heart of the system. They will make or break it. Ok, actually thats install, but speakers are more glamorous then MDF so....
Short answer, yes upgrading speakers alone will make a noticable improvement. To get the most from them however you should get an amp to drive them with.

Say i do decide to upgrade just the speakers to some higher output ones. like those rated at 40watts min and 220watts max for the front 6.5''s and a similiar deal for the rear 6x9's.  Will the stock stereo/cd changer have trouble powering those speakers up?

Your stock reciever can power anything, including a massive 18" sub if you choose. The question is how efficiently. You have X amount of watts, and thats that. You can use those watts on anything, but without more watts or more efficient speakers it wont change the overall volume to any noticable degree. Also, dont worry about speakers max rating. Just worry about the RMS ratings.

Now say i got a 4 channel amp to increase the power(lets say a 400-500watt amp).  And get upgraded 6.5''s front and 6x9''s rear. would i only get high sound and not bass or will the bass be improved too?  also would i have to upgrade tweeters with the extra watts added.   Will a sub and seperate amp be needed to balance it all out? like say a 300 watt sub and amp.

The bass will be improved. Depending on exactly what you get it could be improved anywhere from a little bit to quite a good degree. Smaller speakers just arent all that good at playing bass regardless of how its set up (It can be done very well in certain applications but thats outside the scope of this thread by a large margin).
For good bass you need 2 things, lots of cone area and lots of power. You can trade off (More cone area, less power, more power less cone area) but thats the real ingredients. Even 6.5" speakers can have decent bass though so dont think you HAVE to have a sub. A good component set with a nice amp would give you a well rounded system.

Are there any 5 or 6 channel amps designed for 4 speakers and a sub? just to have it all in one amp.  Scratch that. just saw the prices on 5 and 6 channel amps. I noticed that some of the newer Xterra models(2003s) had a sub enclosure built in the back area. So if i did go with that i'd probably check junk yards and pull one out just so it will fit on the side of the rear area and be low profile.  The custom fiberglass thing looks like a pain in the ass to do. Plus i dont know much about it like how to mount it .

Custom fiberglassing is indeed a pain in the ass. Its not impossible to do, its really not all that difficult. You just have to be very patient and very thorough. Finding the sub box aat the junk yard would make things alot eaiser.
As you found out, good multi channel amps get pricey fast. Additionally, I dont care for them as they always seem to be a compromise in one form or another. I either dont get the features I want, dont get the bridgibility I want or dont get the power I want.

Being that the stock system has tweeters, i guess it must have cross overs too? Would i need to upgrade those maybe?

No easy answer. You dont NEED to replace the crossovers, however crossovers (good ones) are matched to the speakers. You dont just swap crossovers willy nilly. One advantage to buying a component set, it includes a matched crossover. Additionally, the crossovers have to be rated for the power your driving your subs with.

and RMS watts is normal hearing volume level as opposed to max output ratings that are the max right?

No. RMS is root mean squared watts, or the constant power available. Max is peak, what the equipment can hit but not sustain. Additionally, max power usually comes at the cost of greater heat output and degradation of sound, so personally I only look at RMS ratings.

since this system is maybe 4x45watt it operantes normally in about 24 or so regularly? so adding 50watt min 220watt max speakers will probably not be a good idea?  Im not sure.

It operates wherever you have the volume set at. Thats about it. Dont get caught up on watts, dont get caught up on max.

Im not looking into a crazy ass dual sub system, Just something much better than the crappy sound that it has now. Let me know what im doing wrong here.

Except for focusing on watts tooo much, your doing nothing wrong. As I said in my first part, keep it simple. Get a good component set, a nice sub and 2 amps. I say axe the rears because I do not like rear speakers, and in competitions it will get you dinged hard. But ultimately its personal preference. If you want them, keep them!

Share your ideas on this.   Edited to add. i want to keep the 6 CD changer so ill try and avoid getting a different head unit for this. Thanks in advance.

See my first reply.

Quoted: Being that the stock system has tweeters, i guess it must have cross overs too? Would i need to upgrade those maybe? No easy answer. You dont NEED to replace the crossovers, however crossovers (good ones) are matched to the speakers. You dont just swap crossovers willy nilly. One advantage to buying a component set, it includes a matched crossover. Additionally, the crossovers have to be rated for the power your driving your subs with.

 

With an amp installed. Are both the tweeter and front speaker will be connected to the same channel?  If so i might just try it out w/o the tweeter.  Then maybe install one later that comes with a specific cross over for it. Depending on what type of cross over it needs.

I also noticed that the stereo has no pre-amp outputs so i guess ill need one of these www.crutchfield.com/S-T1sWcXZDiss/cgi-bin/ProdView.asp?g=721&I=142SLC4
It looks simple enough. just connected the correct speaker wires to this instead and out to the amp.

thanks again.

Quoted: Quoted: Being that the stock system has tweeters, i guess it must have cross overs too? Would i need to upgrade those maybe? No easy answer. You dont NEED to replace the crossovers, however crossovers (good ones) are matched to the speakers. You dont just swap crossovers willy nilly. One advantage to buying a component set, it includes a matched crossover. Additionally, the crossovers have to be rated for the power your driving your subs with.   With an amp installed. Are both the tweeter and front speaker will be connected to the same channel?  If so i might just try it out w/o the tweeter.  Then maybe install one later that comes with a specific cross over for it. Depending on what type of cross over it needs. I also noticed that the stereo has no pre-amp outputs so i guess ill need one of these www.crutchfield.com/S-T1sWcXZDiss/cgi-bin/ProdView.asp?g=721&I=142SLC4 It looks simple enough. just connected the correct speaker wires to this instead and out to the amp. thanks again.

To your first question.
Ha. You asked for it.
Simple answer, yes. Essentially what you do is treat your crossover as the "speaker" and wire the amp to the crossover, then the crossover out to the tweeter and mid.
Unless your using an active crossover, in which case you place that in line before the amp. Which allows you to run an amp per tweet and an amp per mid. Or, you can use a crossover per speaker and run a channel per speaker rather then a channel per side (Side being midrange and tweeter).
So you could either run 1 amp per speaker set (1 amp for tweeters, 1 amp for midrange) or you could run 1 channel on the amp per speaker (4 channels, 2 for tweets and 2 for mids). Or, if your amp allows you could get funky and bridge all of the above together on 1 channel. I dont know how to do that off the top of my head, but I'm sure it could be done.

Make sense?

Most of that is well beyond the realm of just "upgrading" though. So, for all practical purposes and what 99% of the people do is run 1 channel per side, with a side being 1 tweeter and 1 midrange. Run the channel to the crossover inputs, then on the crossover outputs run those to the respective speakers.

A bit more info on crossovers. They are not "one size fits all" if you want a proper crossover. How the crossover is designed is based upon the speakers used, crossover points desired, expected power and the design of the crossover itself. For example, you might have a crossover that is set to...ohhh...say 3000 hertz. If you swap the tweeter, just by the different specs on the tweeter you might change the crossover point to  say 4500 hertz. Now you end up with a nasty hole in a critical range of sound. Or you might alter it to 2000 hertz which sends too much bass to the tweeter and blows it.
I love crossovers, because they are SO overllooked and SO taken for granted when in fact a good crossover is a work of art in and of itself.

Back to simplicity though. You can tinker around with whatever however, just dont drive them hard while you are.

Personally, I recommend just buying a decent component set from the get go and be done with it. I like CDT's although I've heard the midrange takes a bit of TLC to get good bass out of. JL Audio makes very good components as well. Infinity is always a very good neutral set as well.
I dare say anything else I would mention may be more then your willing to pay (And most likely you dont want to drop 1000+ for CDT's highest end component set either).



As for the other point. Yes, you will need either a line level converter (The box you linked to) or an amp that accepts speaker level inputs. The LLC gives you more options as it allows you to use any amp on the market.

Quoted: Quoted: Quoted: Personally, I recommend just buying a decent component set from the get go and be done with it. I like CDT's although I've heard the midrange takes a bit of TLC to get good bass out of. JL Audio makes very good components as well. Infinity is always a very good neutral set as well. I dare say anything else I would mention may be more then your willing to pay (And most likely you dont want to drop 1000+ for CDT's highest end component set either). As for the other point. Yes, you will need either a line level converter (The box you linked to) or an amp that accepts speaker level inputs. The LLC gives you more options as it allows you to use any amp on the market.

Wow, my head hurts.  Now i am wondering whether i should get the component set or just get the tweeters out of the picture.   If I didnt have full time credit hours this semester to study for i'd probably do more research on this cross over stuff.  
In your guy's opinions, just how important are tweeters?  Worrying about cost vs quality, i'm almost at 50/50 here with that issue.  [insert head exploding animation here]

Quoted: Quoted: Quoted: Quoted: Personally, I recommend just buying a decent component set from the get go and be done with it. I like CDT's although I've heard the midrange takes a bit of TLC to get good bass out of. JL Audio makes very good components as well. Infinity is always a very good neutral set as well. I dare say anything else I would mention may be more then your willing to pay (And most likely you dont want to drop 1000+ for CDT's highest end component set either). As for the other point. Yes, you will need either a line level converter (The box you linked to) or an amp that accepts speaker level inputs. The LLC gives you more options as it allows you to use any amp on the market. Wow, my head hurts.  Now i am wondering whether i should get the component set or just get the tweeters out of the picture.   If I didnt have full time credit hours this semester to study for i'd probably do more research on this cross over stuff.   In your guy's opinions, just how important are tweeters?  Worrying about cost vs quality, i'm almost at 50/50 here with that issue.  [insert head exploding animation here]

Tweeters are important, very important.

Just get something like This
If thats too much do the TR's. Or some Infinity's.

That will set you up nicely.

As for crossovers, just do a google search for "Crossover design calculator" or "homemade crossover" or something like that.
Theres alot to it, but if your into audio it makes for a fun research project.

Got it. Components it is.  

I've been looking at a couple of amps and i like one with
"Preamp-level inputs (speaker-level to preamp-level adapter included) "
That way i just connect to the amp using a factory head wiring harness and avoid the trouble of the RCA converter.

Now i want to figure out what materials i need to create a wiring harness like this one.  It looks well isolated so that it doesnt have any issues with bad noise.
xterrafirma.com/modules.php?op=modload&name=Subjects&file=index&req=viewpage&pageid=26

In that case, can you explain high/low level input?

thanks