my friend just happed to buy a corvette and he knows i know a lil about car stereo's.
he wants to have good sound in his car but there is not alot of room in the back because of his t-tops. up front i got him some 4x6 eclipse 2 ways, in the back i got him some infinity kappa 6x9 3 ways, we have these in boxes. as he wants it to sound good i told him that his door speakers sould be amp'd. i will be selling him my crossfire vr-404 witch is 50x4 RMS. we were thinking about maybe putting an 8" sub in the back to give it some lower end. but the sub may come later on.i was thinking we would go with a 4 ga wire kit.
the problem that i have is, his battery is mounted in the back not up front like most cars. how do u run the power wire to the amp? can i also ground the amp out on the neg side of the battery also ? would i have to make the wire from the alt to the batt bigger ?
any help is great thanks
chris
Replies (11)
SQLThump on 06/18/2008 17:24:42
This can make things much easier in fact. Is the battery in the little "slot" behind the seats? I am assuming yes, as there isn't a real trunk in 'vettes of that era. If possible, mount your amp under a seat if there is no clearance issues to save space.
Run a power wire directly from wherever the battery is mounted, and use as short of a ground as possible from the amp. DO NOT GROUND TO THE BATTERY!!! Your amp can probably be fine with 8AWG if you are using a single, modest amp. Your alternator cable should be fine as well as long as again, you use modest power. Sports cars are usually strapping above average, but not great alts, and if the battery is trunk mounted, cable is not cheaped out on either. A stout charging system affects nearly every aspect of a vehicle, and sports car designers fortunately know this, even if nobody else besides the truck guys care.
If you are planning to use that crossfire amp alone, it may be a bit weak for pushing all 4 speakers+an 8" sub. If something around 100RMS at 2 ohms is used, you can get clean power to all of the speakers a bit better, and can then use the rear channels bridged together for the sub to save on overallspace, and more importantly in a Vette, precious weight.
swez on 06/19/2008 05:16:55
This is a good challenge to any car audio installer for reason noted by SPLThump. However, having the battery mounted if the back can make it easier to wire up power cables for the amps used.
The 4x6 Eclipse speakers will have to be crossed over at midrange levels above 300 Hz. (If not higher) The rear 6x9's can be crossed lower and still have good MB/MR/HI's. This will take time and experimentation to determine the best crossover settings from this Crossfire amp.
As for the Bass Engine, one has to look at how much space is available for the sub enclosure and plan accordingly. (Careful measuring and placement options) Here, a single 8" or 10" sub is probably sufficient and powered at 150-250 watts is plenty. Sealed subs need minimal space for the box. Ported designs require more box space, but net better deep lows.
A #4 gage power line set is fine for this app. A #8 to the Crossfire and another #8 to the sub amp is fine as long as the ALT/BAT can deliver sufficient power to both amps.
There are a few tricks to consider as well. If you can add a 6.5" MB driver to the front stage, this would be a plus.
Comments?
Swez
UKinstaller on 06/19/2008 06:20:56
i disagree on not grounding to the battery. the entire car is fiberglass, you really only have a few choices. battery is going to be closest by a LOT. other option is grounding to bolt holding down driver or passenger seat, should be metal. I did a full system in a 1966 vette once and grounded to the battery, worked great, no noise or dimming lights whatsoever.
-UK
SQLThump on 06/19/2008 06:35:37
I didn't even think about that UK..........I probably would have been the only person wondering why the amp wasn't working when grounded to fiberglass.........GRIN
Ash on 06/19/2008 12:50:44
A couple of 8" subs would be perfect for the limited space. Getting them down to a lower Q sealed will be relatively easy with a still small box. Adding sloped downfiring to the mix will also help with the acoustics and stealthiness if chosen.
Agree with Swez on the 4x6".... Depending on the crossover's slope, a range around 250-300hz is good. This brings it just above the midbass bandwidth that will blend well with rears and sub, but will also tout much clarity.
The rears only need to fill in and may not necessary need full power. HU power with high pass passives (150hz) could work, but if they are amped, they may need to be turned down a little so as not to offset the front stage. A set of 4x6" plate comps may fair better with power, output, and overall performance if they are going to be the sole front stage providers.
The right 4 channel amp could run this setup easily as there are quite a few good 8" dual 4's out there. Something with about 75 rms watts per channel (250-300 bridged) is a good compromise that will keep the fronts clean and still have enough power for some decent subs.
ttocs on 06/19/2008 13:05:30
You don't need much in a hatch like that to have good bass, a single 8 would be ok, dual 8's great.
And yes there is nothing wrong with grounding to the battery. If I could do it easily on my system I would
ckoscin2 on 06/19/2008 14:04:03
i am selling him my crossfire vr404 the 4 channel and on ebay today i found a crossfire vr-402, 400 x 1 at 4 ohm. he likes rock for music, so i think we will not go ported. as far as a sub goes i think we may go a kicker L5 or L7. not sure just looking to see what he can pick up. but for now we have to find him a HU. he wants a 7" touch screen in dash dvd/cd player. i found a few used eclipse ones on ebay, but he wants a cheap $300-400 one from wal-mart. im trying to tell him that he can find better ones somewhere else
ttocs on 06/20/2008 11:53:49
I have never been a fan of kicker myself. Their subs tend to need too much power to sound good IMO.
swez on 06/22/2008 02:57:52
Kicker makes some solid amps and their subs L5/7 subs work best in large ported enclosures and lots of power from the amp.
Consider a smaller format enclosure and scale the system to meet the space this Vette has available. A 250-300 watt bass engine would be plenty in this car.
Am not sure how much ALT power this car has, but would not be surprised to see a 70-85A as the top limit for this vintage. Keep that in mind in this design.
Swez
ckoscin2 on 06/24/2008 06:24:35
off ebay i got him a new crossfire vr-402 400w x1 rms, and i used diamond audio m3 8" duel 2 ohm vc, so we can run the amp at 4 ohm. then he will be amping the door speakers with the crossfire vr-404. would 2 leads of 8 ga wire be good for the amps?
he wants to grab a 7" indash dvd player but he is not sure what one to get. and im not sure also.. he is trying not to go over 400 bucks. but i think the ones that are like 350 new off ebay wouldnt have a great display. what are some good ones to have him get or look into ? i was trying to find him a good used eclipse, pioneer one off ebay.
Ash on 06/24/2008 07:10:55
Not too keen on in-car dvd's, but I would be careful buying used headunits. No matter what brand, they still have wear & tear limits as there is mechanical components. The only used that I have leerily bought is amps. Mechanical gear (speakers & HU's) I tend to buy new when I can afford.
If you can find someone that bench tests or can prove that all functions normally, then I suppose it would be okay. However, off of ebay you have to be real careful and make sure that they have a feasible return policy.
he wants to have good sound in his car but there is not alot of room in the back because of his t-tops. up front i got him some 4x6 eclipse 2 ways, in the back i got him some infinity kappa 6x9 3 ways, we have these in boxes. as he wants it to sound good i told him that his door speakers sould be amp'd. i will be selling him my crossfire vr-404 witch is 50x4 RMS. we were thinking about maybe putting an 8" sub in the back to give it some lower end. but the sub may come later on.i was thinking we would go with a 4 ga wire kit.
the problem that i have is, his battery is mounted in the back not up front like most cars. how do u run the power wire to the amp? can i also ground the amp out on the neg side of the battery also ? would i have to make the wire from the alt to the batt bigger ?
any help is great thanks
chris
Replies (11)
SQLThump on 06/18/2008 17:24:42
This can make things much easier in fact. Is the battery in the little "slot" behind the seats? I am assuming yes, as there isn't a real trunk in 'vettes of that era. If possible, mount your amp under a seat if there is no clearance issues to save space.
Run a power wire directly from wherever the battery is mounted, and use as short of a ground as possible from the amp. DO NOT GROUND TO THE BATTERY!!! Your amp can probably be fine with 8AWG if you are using a single, modest amp. Your alternator cable should be fine as well as long as again, you use modest power. Sports cars are usually strapping above average, but not great alts, and if the battery is trunk mounted, cable is not cheaped out on either. A stout charging system affects nearly every aspect of a vehicle, and sports car designers fortunately know this, even if nobody else besides the truck guys care.
If you are planning to use that crossfire amp alone, it may be a bit weak for pushing all 4 speakers+an 8" sub. If something around 100RMS at 2 ohms is used, you can get clean power to all of the speakers a bit better, and can then use the rear channels bridged together for the sub to save on overallspace, and more importantly in a Vette, precious weight.
swez on 06/19/2008 05:16:55
This is a good challenge to any car audio installer for reason noted by SPLThump. However, having the battery mounted if the back can make it easier to wire up power cables for the amps used.
The 4x6 Eclipse speakers will have to be crossed over at midrange levels above 300 Hz. (If not higher) The rear 6x9's can be crossed lower and still have good MB/MR/HI's. This will take time and experimentation to determine the best crossover settings from this Crossfire amp.
As for the Bass Engine, one has to look at how much space is available for the sub enclosure and plan accordingly. (Careful measuring and placement options) Here, a single 8" or 10" sub is probably sufficient and powered at 150-250 watts is plenty. Sealed subs need minimal space for the box. Ported designs require more box space, but net better deep lows.
A #4 gage power line set is fine for this app. A #8 to the Crossfire and another #8 to the sub amp is fine as long as the ALT/BAT can deliver sufficient power to both amps.
There are a few tricks to consider as well. If you can add a 6.5" MB driver to the front stage, this would be a plus.
Comments?
Swez
UKinstaller on 06/19/2008 06:20:56
i disagree on not grounding to the battery. the entire car is fiberglass, you really only have a few choices. battery is going to be closest by a LOT. other option is grounding to bolt holding down driver or passenger seat, should be metal. I did a full system in a 1966 vette once and grounded to the battery, worked great, no noise or dimming lights whatsoever.
-UK
SQLThump on 06/19/2008 06:35:37
I didn't even think about that UK..........I probably would have been the only person wondering why the amp wasn't working when grounded to fiberglass.........GRIN
Ash on 06/19/2008 12:50:44
A couple of 8" subs would be perfect for the limited space. Getting them down to a lower Q sealed will be relatively easy with a still small box. Adding sloped downfiring to the mix will also help with the acoustics and stealthiness if chosen.
Agree with Swez on the 4x6".... Depending on the crossover's slope, a range around 250-300hz is good. This brings it just above the midbass bandwidth that will blend well with rears and sub, but will also tout much clarity.
The rears only need to fill in and may not necessary need full power. HU power with high pass passives (150hz) could work, but if they are amped, they may need to be turned down a little so as not to offset the front stage. A set of 4x6" plate comps may fair better with power, output, and overall performance if they are going to be the sole front stage providers.
The right 4 channel amp could run this setup easily as there are quite a few good 8" dual 4's out there. Something with about 75 rms watts per channel (250-300 bridged) is a good compromise that will keep the fronts clean and still have enough power for some decent subs.
ttocs on 06/19/2008 13:05:30
You don't need much in a hatch like that to have good bass, a single 8 would be ok, dual 8's great.
And yes there is nothing wrong with grounding to the battery. If I could do it easily on my system I would
ckoscin2 on 06/19/2008 14:04:03
i am selling him my crossfire vr404 the 4 channel and on ebay today i found a crossfire vr-402, 400 x 1 at 4 ohm. he likes rock for music, so i think we will not go ported. as far as a sub goes i think we may go a kicker L5 or L7. not sure just looking to see what he can pick up. but for now we have to find him a HU. he wants a 7" touch screen in dash dvd/cd player. i found a few used eclipse ones on ebay, but he wants a cheap $300-400 one from wal-mart. im trying to tell him that he can find better ones somewhere else
ttocs on 06/20/2008 11:53:49
I have never been a fan of kicker myself. Their subs tend to need too much power to sound good IMO.
swez on 06/22/2008 02:57:52
Kicker makes some solid amps and their subs L5/7 subs work best in large ported enclosures and lots of power from the amp.
Consider a smaller format enclosure and scale the system to meet the space this Vette has available. A 250-300 watt bass engine would be plenty in this car.
Am not sure how much ALT power this car has, but would not be surprised to see a 70-85A as the top limit for this vintage. Keep that in mind in this design.
Swez
ckoscin2 on 06/24/2008 06:24:35
off ebay i got him a new crossfire vr-402 400w x1 rms, and i used diamond audio m3 8" duel 2 ohm vc, so we can run the amp at 4 ohm. then he will be amping the door speakers with the crossfire vr-404. would 2 leads of 8 ga wire be good for the amps?
he wants to grab a 7" indash dvd player but he is not sure what one to get. and im not sure also.. he is trying not to go over 400 bucks. but i think the ones that are like 350 new off ebay wouldnt have a great display. what are some good ones to have him get or look into ? i was trying to find him a good used eclipse, pioneer one off ebay.
Ash on 06/24/2008 07:10:55
Not too keen on in-car dvd's, but I would be careful buying used headunits. No matter what brand, they still have wear & tear limits as there is mechanical components. The only used that I have leerily bought is amps. Mechanical gear (speakers & HU's) I tend to buy new when I can afford.
If you can find someone that bench tests or can prove that all functions normally, then I suppose it would be okay. However, off of ebay you have to be real careful and make sure that they have a feasible return policy.
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