TY for the help need more for a friend

[Coupe 10+ year member]

Recently I had help from this board on my install. I must say the recommendations have been so good that I need more help and I came here first.

My friend has a 98 Jeep Grand Cherokee Limited. Its a 6 speaker setup with a sub woofer. Presently he has a set of Infinity Reference 6.5 component in the front with 6.5 References (non component) in the door and another set on the back. He is going to upgrade to the Reference component on the back in the future.

His 4 channel amp that was powering all six speakers recently blew out. He has another 4 channel amp bridged powering the amp. He wants to keep a 2 amp setup and use the existing 4 channel amp that is still working.

What can he do to power the 6 channel of speakers he has? Is powering 6 speakers on a 4 channel amp bad? I was thinking of getting a 5 channel amp to power the 2 rear sets and the sub and bridging the 4 channel amp to power the components.

What are your recommendations? What would be a good amp to purchase? If you think you have a better idea PLEASE help. I am at a loss trying to help and keep him in a $500-800 budget and sending enough power to all the speakers.

He also has a problem that his amplifiers are under the rear seats and they are probably getting too hot and that is what was messing his amps up. He uses the trunk so its difficult. A friend of his recommended getting an overpowered amp and running it so it would stay cool cause its not using too much power. I was also thinking of using computer fans to circulate air under the seat.

Sorry for so many questions its just I want to help my friend out but not make him waste money.

Maybe he could forget about the middle speakers and spend the money on getting the component set for the rear and just use a 4 speaker and sub setup.

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Argh I dunno what to do!

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[Coupe 10+ year member]

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[audioholic 5,000+ posts]

Many people on here will advise against running rear speakers, let alone 'middle' AND rear speakers. Frankly, Im a bit confused how he has a comp set up front, a non comp set in his doors, and then another set of speakers for the rear. Where is the 'front' set mounted, if not the front doors? Or is the 'middle' set you are referring to actually mounted in the rear doors? Your description of speaker location is confusing. But even so, Id tend to suggest amp'ing the front speakers alone, and pushing any other speakers off the deck power.

 

[Coupe 10+ year member]

Many people on here will advise against running rear speakers, let alone 'middle' AND rear speakers. Frankly, Im a bit confused how he has a comp set up front, a non comp set in his doors, and then another set of speakers for the rear. Where is the 'front' set mounted, if not the front doors? Or is the 'middle' set you are referring to actually mounted in the rear doors? Your description of speaker location is confusing. But even so, Id tend to suggest amp'ing the front speakers alone, and pushing any other speakers off the deck power.

Its front door and dash for the comps. Rear doors by your feet have one set of 6 1/2. In the back where the hatch is there is a factory mounted speaker housing on the top, mounted to the roof liner.

It is the Infinity system for the Jeeps.

Why should you only run one set of speakers in the front only?

 

[audioholic 5,000+ posts]

Mount the comp set in the front doors exclusively, do not reflect the tweeters off the windshield like most dash installs, if you can help it. Amp the front doors.... and the rest you can push via the deck power, or turn off completely. If he really insists on a 4-channel, amp the front and rear doors, heavily bias towards the front, and run the rear rear speakers off the deck, if at all.

 

[oldschool4me 10+ year member]

switch to a midbass in the rear and rear doors.

 

[Alpineforever 10+ year member]

so he has mids in the door,

tweets up on the dash firing into the glass

and 6x9's or 5x8 coaxials in the back?

I think that's what you're trying to say.

Before you look at getting an amp your going to have to figure out how they crossed over the tweeters and mids. I have no clue how they normally do it factory, but if they have inline crossovers then you'll have two sets of wires per side and you could power the frotn with a two channel one mid and tweet perchannel, assuming they are 4 ohm speakers they'll probably end up at a 2 ohm load per channel, but once again, that's not definite, I'm just assuming they're using 4 ohm speakers. The other possibility is a single crossover per side like how most component sets come, and then you would have one wire per side, and once again a two channel would get the job done.

To power the rear's you could either run them off of head unit power, or get a 4 channel and just run all 6 speakers off of that.

if you have two sets of wires on each side, just make sure he gets a 2 ohm stable amp just in case, hopefully some more people chime in

 

[audioholic 5,000+ posts]

switch to a midbass in the rear and rear doors.

The problem with that idea is, midbass is easy to localize, so it should be part of your front stage. If you run dedicated midbass in the rear, the tendency is to let the front midbass setup suffer, many times even turned down or off (high passed too high), pulling the sound stage to the rear.
But we are discussing a 6-speaker full-range system here, for a friend. He probably just wants it loud, and wont even notice the poor imaging characteristics, so maybe your suggestion isn't so bad. *shrug*

 

[Coupe 10+ year member]

Mount the comp set in the front doors exclusively, do not reflect the tweeters off the windshield like most dash installs, if you can help it. Amp the front doors.... and the rest you can push via the deck power, or turn off completely. If he really insists on a 4-channel, amp the front and rear doors, heavily bias towards the front, and run the rear rear speakers off the deck, if at all.

I would consider the rear doors are useless since they are so low. The rear top mounted speakers are angled to the front with room for a tweeter setup too, which I believe would really fill out the car.

I have no way to change the way the tweeters in the front are mounted without too much modding. I really don't understand why you should do front only?

 

[audioholic 5,000+ posts]

I would consider the rear doors are useless since they are so low. The rear top mounted speakers are angled to the front with room for a tweeter setup too, which I believe would really fill out the car.
I have no way to change the way the tweeters in the front are mounted without too much modding. I really don't understand why you should do front only?

You could mount the tweeters braxially (tweeter directly in front of mid, like a coax). You could either make a bracket to do this, buy a comp set that has the option already, or just say screw it its for your friend anyway, and bounce them off the glass. *shrug*
People say fronts only because music is recorded in stereo. Stereo means 2 channels, not 4, not 5.1, not 6, etc. This means the sound is recorded in such a way that is meant to be reproduced back to you in... yes... 2 channels. One left, one right, in front of you. Many people argue having speakers all around you sounds better. It may fill the space in your vehicle better due to poor acoustics and/or poor front speakers/mounting locations, but it adds a fundamental flaw to your reproduction of the original recording... extra channels of information not designed to be there.

So you may wonder, if the right front and rear are both playing the same thing, what's the problem. Well for one, again the system is meant to be placed in front of you, to create a sound stage. A properly dialed-in system will allow you to close your eyes and picture where each instrument in the band is, on stage, when the recording took place.

Stereo recording allows for spacial depth information to be stored, and reproduced. Just as you have two eyes to see with 3 dimensions, you have 2 ears to hear in 3 dimensions, and 2 speakers can reproduce sound in 3 dimensions. But when you start adding speakers all around you, behind you, etc... it interferes with the systems ability to place the sound stage 3-dimensionally. Are the front speakers trying to place the sound stage in front of you, across the dashboard? Or are the rear speakers trying to place the sound stage behind you, across the rear parcel shelf? the answer is both, and the will each demand your attention. So much so that they will interfere with each other, your sund stage wont be on the bash, or the parcel shelf, it will be smeared throughout the car with no real coherence. But how many people do you know who would realize this, when all they are use to is listening to local FM stations on their Panasonic boom box? So people hear those rear speakers fill a void in the rear of the car that the front speakers, due to physical limitations of their mounting position, listener position, and seating arrangement, cant fill themselves... and they think 4 speakers is superior to 2.

The purist wants only 2 speakers in his ride. The every-day person thinks they want 48 speakers. Somewhere in the middle is where most people end up compromising with.

 

[Coupe 10+ year member]

You could mount the tweeters braxially (tweeter directly in front of mid, like a coax). You could either make a bracket to do this, buy a comp set that has the option already, or just say screw it its for your friend anyway, and bounce them off the glass. *shrug*
People say fronts only because music is recorded in stereo. Stereo means 2 channels, not 4, not 5.1, not 6, etc. This means the sound is recorded in such a way that is meant to be reproduced back to you in... yes... 2 channels. One left, one right, in front of you. Many people argue having speakers all around you sounds better. It may fill the space in your vehicle better due to poor acoustics and/or poor front speakers/mounting locations, but it adds a fundamental flaw to your reproduction of the original recording... extra channels of information not designed to be there.

So you may wonder, if the right front and rear are both playing the same thing, what's the problem. Well for one, again the system is meant to be placed in front of you, to create a sound stage. A properly dialed-in system will allow you to close your eyes and picture where each instrument in the band is, on stage, when the recording took place.

Stereo recording allows for spacial depth information to be stored, and reproduced. Just as you have two eyes to see with 3 dimensions, you have 2 ears to hear in 3 dimensions, and 2 speakers can reproduce sound in 3 dimensions. But when you start adding speakers all around you, behind you, etc... it interferes with the systems ability to place the sound stage 3-dimensionally. Are the front speakers trying to place the sound stage in front of you, across the dashboard? Or are the rear speakers trying to place the sound stage behind you, across the rear parcel shelf? the answer is both, and the will each demand your attention. So much so that they will interfere with each other, your sund stage wont be on the bash, or the parcel shelf, it will be smeared throughout the car with no real coherence. But how many people do you know who would realize this, when all they are use to is listening to local FM stations on their Panasonic boom box? So people hear those rear speakers fill a void in the rear of the car that the front speakers, due to physical limitations of their mounting position, listener position, and seating arrangement, cant fill themselves... and they think 4 speakers is superior to 2.

The purist wants only 2 speakers in his ride. The every-day person thinks they want 48 speakers. Somewhere in the middle is where most people end up compromising with.

Sounds like a very valid point and it does make sense. Much like one light source you can illuminate a whole room with good position and reflection.

Unfortunately, it has nothing to do with screw him he's just my friend. You are an audioholic and I'm just a slightly above mainstream listener. Sure I spend about an hour or two adjusting EQs and gains. I rewired his whole system to make sure its hooked up right, but I am not as much as a fanatic as you, to start modding his whole vehicle. I am not that skilled or experienced enough where I could physically mod and then have the ears to make sure its right. I try using fade and gains to keep most sound in front and I do a pretty decent job of making it sound good.

Also to mount like a coaxial is counter productive to me because the speakers are about shin high. People will block the audio reflection with their legs.

I would like to keep the setup as even as possible because it was designed by professional engineers and Infinity as a premium sound system. So why reinvent the wheel?

HOWEVER, I must say I do like your idea about wiring one set on the radio. Apparently I got ahead of myself and didn't think of the obvious solution. What do you think about mounting the amps under the rear passenger seats? I thought it would get too hot. I was thinking to take some computer fans and trying to get air to circulate under there. Would that work? Should I build a vertical mount in the trunk to save space and give proper air?

What 4 channel amp would you guys recommend? It will power comps in the front and far rear.

 

[audioholic 5,000+ posts]

In most cases, mounting an amp under a seat works just fine. Unless you are running the amp at its lowest possible impedance, and it will be crammed in so tight it has no air space around it, I wouldn't worry about it too much. Try it, if over heating becomes a problem, then add a fan. Chances are, it wont be necessary.