Ok,

I have been looking into some options for car audio recently. and I want to build a system only using one amp. My first option was to find a 5 or 6 channel amp, but its either real cheap crap or way too expensive. So i'll be powering it with a 4 channel. Since all 4 speakers in the Falcon are the same size, I will be buying 2 pairs of them (i don't want splits), and one 10-12" sub.

So a little background on how i attacked this when I was young and stupid, I had a 4 channel amp running 1 sub and all 4 speakers in my pulsar. Though, people said i was nuts, I was told many stories, yet I never had one problem and it pumped hard.

The diagram shows how I used to have it wired up. (all 4 speakers running off 2 channels and the sub bridged on the rear output) Now, I am an audio engineer by trade so i understand wattages, filters and the like but the electronics side always seems to fly over my head. I know the sub and speakers that i will be buying are 4ohm. But if i connect the speakers the way i have done in the diagram it will lower the amp rating to 2ohm, therefore I need to buy an amplifier that can handle 2ohms.

THE QUESTIONS I NEED ANSWERED;
Since the front outputs will drop in ohms, will that effect the sub which is bridged?? And is there anything else that could go wrong?

I've had people tell me it won't, and people that have told me that if you drop one half of the amp to 2ohm, then the whole amp runs at 2 ohm, therefore if I'm running a 4ohm sub it will do damage to it

Now before any of you decide to attack. I do realise that the fronts and the rears will be at the same volume/frequency and that i can not control that anymore.

if you do do that the speakers will run at 2ohm?!?

you can get ohm really nice 2 ohm 6.5" splits that are on ebay, i was going to get them but they are 2ohm and no good for me


why not just power the fronts off the amp and the sub? just like most ppl and forget about the rears or run them off the deck..

or slot the V8 into the verada for the best of both worlds, c'mon you know you want to lol

if you do do that the speakers will run at 2ohm?!?

you can get ohm really nice 2 ohm 6.5" splits that are on ebay, i was going to get them but they are 2ohm and no good for me


why not just power the fronts off the amp and the sub? just like most ppl and forget about the rears or run them off the deck..

or slot the V8 into the verada for the best of both worlds, c'mon you know you want to lol
No, if you connect two set of 2ohm together like the diagram, that will bring the amp rating to 1ohm!! lol

And yes, if i knew how much the sprintex would of sucked on my car, i would of dropped an LS1 into it.. and keep it FWD :bowrofl:

Just do it, it will run fine.

Each channel has it's own amplifier, and each of those amplifiers on the front speakers will have 2ohms of resistance with two 4ohm speakers in parallel (as you know) this will not effect the rear, or sub channels that will be combined to power the sub.

OR

Do as Andrewd said, run the rears of the deck, thats what I would do.... (if I didn't have a 6chan amp)

Just buy a dual voice coil sub, run each coil off 1 channel (get a 2 x 2ohm sub).
I've done it before and it has run fine for ~12months. If the amp supports 2ohm why not, then you don't have to worry about particular ch's running at 2 or 4ohm, not sure how that works.

Just do it, it will run fine.

Each channel has it's own amplifier, and each of those amplifiers on the front speakers will have 2ohms of resistance with two 4ohm speakers in parallel (as you know) this will not effect the rear, or sub channels that will be combined to power the sub.
Thats what I've been thinking the whole time, but I just wanna clear the air. Thanks

Hey mate, if you run your speakers in parallel, they will drop to 2 ohms, if you run the speakers in serial, they will still operate at 4 ohms.

'caus your fully hektic amp (hehe nice one) is using 2 channels to run four speakers, if you run them in serial you'll have less power, but your amp will operate at 4 ohms, if the amp is 2 ohm (or less) compatible then run them in paralell as you'd be getting similar wattage to if you ran each individual speaker to a channel.

Mrmacomouto has the right idea, it will only affect the speakers you run in parallel, mind that you can't run the subwoofers in parallel unless you have 2 (or you could get a chunky ass 4ohm resistor compliant with the wattage or your amp and run it paralell to your sub) but that's rather dodgy lol.

Hope that helps man!

Hey mate, if you run your speakers in parallel, they will drop to 2 ohms, if you run the speakers in serial, they will still operate at 4 ohms.

'caus your fully hektic amp (hehe nice one) is using 2 channels to run four speakers, if you run them in serial you'll have less power, but your amp will operate at 4 ohms, if the amp is 2 ohm (or less) compatible then run them in paralell as you'd be getting similar wattage to if you ran each individual speaker to a channel.

Mrmacomouto has the right idea, it will only affect the speakers you run in parallel, mind that you can't run the subwoofers in parallel unless you have 2 (or you could get a chunky ass 4ohm resistor compliant with the wattage or your amp and run it paralell to your sub) but that's rather dodgy lol.

Hope that helps man!
Yeah cool i know the ohms will drop for the front channels but I was worried the rear would drop aswell as the amp is one unit.

I won't be running anything in "series" as that is mega dodgy!

People think I'm trying to be a cheapskate but it works the same principal as most dual voice coil sub setups. Just gotta make sure I get the right wattage amplifier.

as long as the amp is 2ohm stable then that will work fine
will also be bloody loud
also afaik if you run 2 4ohm speakers in series you get an 8ohm load

also afaik if you run 2 4ohm speakers in series you get an 8ohm load
Correct!!

Forgot about that, thats why i never connect in series. Its pointless for car audio purposes.

Ah, just like my audio setup. Blew the front speaker connections, so had to run the fronts into the back connectors, along with the back speakers. lol

It works fine, the system just distributes the load evenly. I got told that I may need to run them at higher volumes to get the same sound, but after connecting them up all 4 ran fine, no loss of power or sound quality.

I previously had a 4chan amp running my fronts and sub and the rears off the deck, works fine, just have to remember to tune your sensitivity so your rear fill isn't completely lost or it'll sound too bright.

just do it, whats the worst that can happen.
just wait till someone smacks up their car and buy a new amp cheap ^^

hehehe unfortunately...that amps most likely to come off my new car :P

Run the rears off the deck...

Problem solved.

ummm does the stock ford h/u's come with pre-outs? or do you have to buy those in-line converters?
cause in that case you can run any speakers off of the deck

Run the rears off the deck...

Problem solved.
Exactly what I was about to say.

I doubt you'll even notice the difference, after all, you are in the front.

ummm does the stock ford h/u's come with pre-outs? or do you have to buy those in-line converters?
cause in that case you can run any speakers off of the deck
I'll be getting an amp that has high level-ins

no, don't.

http://www.fordforums.com.au/showthread.php?t=24724

Yeah cool i know the ohms will drop for the front channels but I was worried the rear would drop aswell as the amp is one unit.

I won't be running anything in "series" as that is mega dodgy!

People think I'm trying to be a cheapskate but it works the same principal as most dual voice coil sub setups. Just gotta make sure I get the right wattage amplifier.

Yeah that's it mate, just make sure the amp can handle 2 ohms and even better 1 ohm (as you will get better sound quality) the reason why is because the speaker can and will change it's impedance depending on the frequency it is producing, this happens differently with different speakers and subs exc, and often even 4ohm subs can go down to 1.5ohm exc. It's not a big deal, but if your unlucky enough to have a noticeable sound degradation every so often then it may bother you. However 99% it shouldn't be an issue as an rewiring the speakers is going to get them sounding better anyway!

If you want to know, just type speaker impedance curve into google or wikipedia.

Cheers man!

Yeah that's it mate, just make sure the amp can handle 2 ohms and even better 1 ohm (as you will get better sound quality) the reason why is because the speaker can and will change it's impedance depending on the frequency it is producing, this happens differently with different speakers and subs exc, and often even 4ohm subs can go down to 1.5ohm exc. It's not a big deal, but if your unlucky enough to have a noticeable sound degradation every so often then it may bother you. However 99% it shouldn't be an issue as an rewiring the speakers is going to get them sounding better anyway!

If you want to know, just type speaker impedance curve into google or wikipedia.

Cheers man!

Name me a 4ohm sub that can go down to 1.5ohm, and then supply me the graph. Most subs suffer impedence rise as there frequences drop, not indepence drop.

Name me a 4ohm sub that can go down to 1.5ohm, and then supply me the graph. Most subs suffer impedence rise as there frequences drop, not indepence drop.

Yeah, and the opposite likely happens when they get into their higher frequency range (200hz exc) I've found a few before, if you look like i did i'm sure some will turn up!

It doesn't just happen with subs either!

Get an amp that will handle the load your subs are wired at, amp ratings already factor in impedance changes. It's when you load your amps below this that they will go into protection

With amps you want headroom for good SQ. Headroom comes from lots of power.

Correct the more you load it down the less control your amp has over your speaker, but this is negated by the benefit of having extra power at your fingertips for all practical purposes

Get an amp that will handle the load your subs are wired at, amp ratings already factor in impedance changes. It's when you load your amps below this that they will go into protection

With amps you want headroom for good SQ. Headroom comes from lots of power.

Correct the more you load it down the less control your amp has over your speaker, but this is negated by the benefit of having extra power at your fingertips for all practical purposes

I second this!

It's not as important when working with subwoofers and the like because the audio frequencies they produce are very limited. I Wouldn't go running front or rear speakers of 1ohm as you would likely lose a lot of sound quality!

Well after some careful deliberation, I have bought myself the following;


- 2 x sets of Alpine Type S (5x7") splits... yes 2 sets of splits!!
http://www.alpine.com.au/products/product.asp?modelID=169

- Alpine 4 Channel Amp (MRP-F450)
http://www.alpine.com.au/products/product.asp?modelID=250

- 12" Kicker CVT slimline sub in slimline box.
http://www.hookedontronics.com/show_product_details.jsp?cid=40202



All this from my mate who works at JB for $900 (normally be around $1400-1500)

I will be wiring it like the diagram in the first post. I was really against getting splits as i think they are way too happy up top, but I think its better to break up the frequencies (I'll just turn the treble down). The reason I got 5x7s all round is that all falcons from AU onwards only have room for that size and i don't wanna use spacers or cut anything.

Another thing is I'm not going to connect the second set of tweeters (rear) as I believe there will be excessive amounts of treble, I really just wanted to have mid range in the parcel shelf. This will make my system more versatile in the fact that if I think there isn't enough high end, its as simple as wiring up the tweeters to the crossover.

Also I know I'll be under powering this sub by half but I've heard this sub work off this particular amp and let me tell you I know that I won't be punching any louder than that.

Thought you were all for the JL Audio 5x7"s? You confuse me, I thought you hated splitslol

Do the BA's have a spot for the tweeter stock or do you have to do some custom mounting for that?

I Wouldn't go running front or rear speakers of 1ohm as you would likely lose a lot of sound quality!
The only thing that changes in sound quality is the Total Harmonic Distortion (THD)

Depending on brand and components used an average 4ohm car amplifier will have 0.01% THD,
dropping that down to 2ohm will make the THD to 0.3% and making it lower (1 ohm if you amp can handle it) will make it go to around 0.9%.

So whether you are running a speaker 16ohm or 1 ohm, the sound quality loss you get is inaudible to the human ear.


Thought you were all for the JL Audio 5x7"s? You confuse me, I thought you hated splitslol

Do the BA's have a spot for the tweeter stock or do you have to do some custom mounting for that?
JL's are overpriced and they pretty much had the same sound quality.
And yes I still hate splits but i didn't want the coaxial speakers.. they looked a bit cheap and nasty.

There is enough room to mount them on the opposite side of the side mirrors.. otherwise ill cut the trim away from the door and mount them flush.

cool demo next thurs night????

haha not going to punch the system that loud LIAR!!

cool demo next thurs night????

haha not going to punch the system that loud LIAR!!

Nah demo will probably be the week after that, my mate had none of that stuff in stock so its all on order.

I must be getting older dude because I hate turning it up too loud. Like those stickers you can buy from autobarn "if its too loud you are too old" lol

Nah demo will probably be the week after that, my mate had none of that stuff in stock so its all on order.

I must be getting older dude because I hate turning it up too loud. Like those stickers you can buy from autobarn "if its too loud you are too old" lol

I'll eventually wear all the little hairs out in my ear one day cause my stereo gets an absolutle raping...

Man i would hook the tweeters up no doubt. i mean i have NFI what they sound like but you get some sets that sound VERY harsh up top and then you have some which sort of blend in nicely. not to harsh like mine....so i would hook them up regardless...you can always turn the treble down..

']I'll eventually wear all the little hairs out in my ear one day cause my stereo gets an absolutle raping...

Man i would hook the tweeters up no doubt. i mean i have NFI what they sound like but you get some sets that sound VERY harsh up top and then you have some which sort of blend in nicely. not to harsh like mine....so i would hook them up regardless...you can always turn the treble down..
Yeah I "might" connect them up and fit them flush into the rear doors

The idea for that came from my mum's A4. The stock standard BOSE system has 2 sets of splits for both front and rear doors, 6x9s in the parcel shelf, and I think a mini sub in the center of the dash. Kind Of a strange setup, plus all the speakers have a dampening protectors as its very hard to distort them.

new car audio is crazy... cant really compare to after market gear... one dude was telling me about the set up in the front of some beemers where there is like 50 drivers lol but seriously they have tweeters in the rear view mirror in some models :shock:

new car audio is crazy... cant really compare to after market gear... one dude was telling me about the set up in the front of some beemers where there is like 50 drivers lol but seriously they have tweeters in the rear view mirror in some models :shock:

When i rock up next to them at the lights ill probably make that rear view shake off from my "good vibrations"
tweeters in the friggin rear veiw pfff