In Car Entertanment?

[Radfax]

Hey all,

Well i will tell you all my story about how i have got myself into this situation. About 2 months back now i bought 2 JBL 12" GT4's sub's thought it was great, i chose a 12 because speeking to the bloke in the shop he said they were better than avarage gave great bass and was more than enough so i thought ah ill settle for the 12's but now i have sold my 12's to buy 2 of the same subs just 3 inches bigger because i have heard these subs will tear a car apart and i just need to have some(you know what its like when you want some thing, you dont give up no mater how ridiculus it might seem).

I was ging to be running. 2 12" jbls off of 2 JBL GTO4000 amps but now i have decided to change my mind. I would preffer to run both of my amps off of one single amp or a mono-block, but i am absoloutely usless with amps so my question is what is the best value for money amp i can buy and still get alot off OMPH from my subs?

I also thought that if i was going to run 2 amps id need a head unit with a 2 ampage output or some thing i dont know what i mean but hopefully some one will and they will be able to set me down the right track.

Thanks in advance!

[CurtisRider]

im confused by some of that, but it may just be me....whats wrong with the 12s?

you cant really use a monoblock amp to power both the subs, seeing as its only got 1 output, so ermm, you would need 2 monoblocks, or an amp with at least 2 outputs, otherwise you would be splitting the power of the monoblock?

to run 2 amps, you will need 2 pre outs, im unsure as to whether there is a product that can double a single output, but i guess its possible to make 1, then again, if your headunit only has 1 preout, its probably pretty shit anyway....get a decent one it makes a difference

[Radfax]

there was nowt wrong with the 12's i just wanted 15 they gave a depper bass and were pure shex.

thanks alot for that so i might aswell just run 2 amps and i need a headunit with a minimum of 2 pre outputs to run 2 amps.

thanks loads Mr paul oliver.

Whats the minnimum watt amp i should runn with 2 1000 peak watt subs?

Tom

Edited August 20, 2006 by Radfax

[CurtisRider]

could run a feck awf powerful 2 channel amp? means you only need 1 preout on the headunit then

by 1000peak, you mean pmpo yeah? not rms, just 1000pmpo sounds rather small for 15s

its not so much how small an amp you can run, its how big a one you can get away with, overpowering is when you will get problems

[Radfax]

oh damn, 1000 was the peak watt on my old 12's i dont know what they are like on 15's because i havent got them yet. i just want some amps that arent to exspensive but will happily power my 15's

EDIT: and yeah it must be pmpo

Edited August 20, 2006 by Radfax

[CurtisRider]

use your existing amp/s then? if they powered your previous ones fine and they are the same peak as these, then itll be fine? personally, i dont see the point in running 2 15s, when will you ever need that much bass, the car will rattle like fag and make it sound crap before you ever really get near their full potential, although it does look cool i guess

[Radfax]

haha, I never bought an amp for my 12's my friend gave me a 700watt amp that was recovered from a car crash and this powered one amp fine and the bass sounded loverly.

[CurtisRider]

haha, I never bought an amp for my 12's my friend gave me a 700watt amp that was recovered from a car crash and this powered one amp fine and the bass sounded loverly.

did you mean sub?

gonna have to start saying whether it was rms or pmpo wattage dude, cos its getting confusing!

as for amps, well, i reckon somebody else better help you choose 1 there, cos im still pretty new to this game, but you really cant go wrong with alpine or jbl

[george_seamons]

You don't have to have 2 amps to power 2 subs. I used to run 2 JL Audio subs of an Alpine monoblock, and it sounded ok. The amp itself wasn't particuarly powerful though, so it didn't sound as good as it could, and it did make the amp work quite hard.

You can easily run 2 amps with only one pre-out. All you need is an RCA splitter. They're about £6 for 2 channel's worth.

As a rough idea, an advertised 1000W sub will probably have an RMS power of about 300 or 400w. Ideally you want an amp that will match this. Try and go with a dedcent named brand, such as Alpine, JBL, JL Audio, Infinity etc, they will always sound better than the cheaper, no named ones.

...Its actually worse to underpower a speaker than it is to over power it...as wierd as that sounds.

[The enchanted broomstick]

as said by george you really dont need two pre-outs from the headunit if you purchase two of these

then you shall be fine for splitting the output which in turn can go into two seperate amps.

However two amps is a huuuuuge drain on battery resources. I would recommend either 1 decent amp powerful enough for the lot or buy a power capacitor which are about £40 from ebay.

I would definately recommend this amp if you want some power though.

http://thebassbin.co.uk/shop/product/products_id/1303.html

Understandably this is only a pro plus amp but its what i have in my car. Its capable of so much its unbelievable. I was running a pair of Vibe QB69's and a 1400 watt Sony 15" sub from it with no problems at all. It has great functions including a 3D surround setting which sounds great and the added bonus of a remote control for the amp which can be tucked into the sun visor. Giving you full control over the volume, bass and treble settings everything, without having to open the boot

[george_seamons]

However two amps is a huuuuuge drain on battery resources. I would recommend either 1 decent amp powerful enough for the lot or buy a power capacitor which are about £40 from ebay.

It's been proven that power caps are completly worthless in a car audio setup. If anybody is really that interested, I will find the link to the various articles. All they are any good for is looks.

I had 2 amps running off just one battery, and I never noticed any drain. I would quite frequently clean the car with my music on, and then start the car. With absolutly no difficulties whatsoever.

[Fish-Finger-er]

dont do power caps, the worst amount of money you could ever spend on car audio, unless your after looks, much better to just get a split charge system, an a second battery, or just a more powerful alternator.

as for the drain from 2 amps being bigger, not really that true. 2 x (200 watts total rms amps) or 1 x (400 watts total rms amp) - im using brackets as im sayin 2 amps vs 1 amp, not the outputs of one amp.

both solutions put 400 watts rms out to your subs. both systems draw- yes youve guessed it 400 watts power from your battery(lets not go into amplifier inefficienes,power loss etc). so works out the same really. just 2 amps take more wiring, gain matching on the 2 set equal, and more boot space. but then do often look more expensive.

[JTM]

Right, you currently have a one preout headunit. Which would suggest that you dont have your front comps amped (if you have even changed them?!?!?) and you probably dont have a very good head unit? So why oh WHY have you bought 2 subs, now sold them, and are buying two more bigger subs?!?! One 15 will hold enough power and drop low enough for your setup I garantee you. f**k me one 12 would suit you better! What front speakers etc do you have? Whats your full system? You really need to have a think what your doing!

[nmt_oli]

I agree with JTM here, i had one 10 in my golf and it was perfect, it is now on a shelf as i sold the box and i am making a flush mount bhox for it. in the mean time, i hooked up the 2 12"Infinity subs out of my van, running off a 600W (@ 2 ohms) kenwood mono block, and it really really hurts- it shakes the car to bits, and overpowers the other speakers, its too much in a hatchback (while good for a phat chevy van though).

Just one of the 12s is great, but my single JBL ten really surprised people. it was only running off a mutant amp, at about 200w RMS and was dropping seriously low for a 10, just ask prawn or tic.

sort the rest of your setup, and dont waste money and space on 15s. If you msut have a 15, just get one, and then get a 10" as well and have a staged sub set up, 15 for the really low stuff, ten for the higher bass.

[JTM]

Dont get me wrong, there is a time and a place for big high powered subs and lots of them. But they are usualyy accompanied by a high quality and equally high powered front end, something i dont think you have to be honest

[Radfax]

i have no head unit at the moment. so i was asking how many pre outputs i need so i can look for this when i finaly choose my headunit, i never said that i had a head unit with 1 pre output.

I am running 2 152 subs because they were the smae price as the 12's were because they had been reduced on sale. At the moment all i own (when the new order comes into the shop) os 2 15" jbl gt4's I do not have any amps headunit or wiring kit, I was asking for advice on what amps and headunit i should get?

Make sence?

Tom

[The enchanted broomstick]

dont do power caps, the worst amount of money you could ever spend on car audio, unless your after looks, much better to just get a split charge system, an a second battery, or just a more powerful alternator.

as for the drain from 2 amps being bigger, not really that true. 2 x (200 watts total rms amps) or 1 x (400 watts total rms amp) - im using brackets as im sayin 2 amps vs 1 amp, not the outputs of one amp.

both solutions put 400 watts rms out to your subs. both systems draw- yes youve guessed it 400 watts power from your battery(lets not go into amplifier inefficienes,power loss etc). so works out the same really. just 2 amps take more wiring, gain matching on the 2 set equal, and more boot space. but then do often look more expensive.

Im afraid to tell you mate that your not quite right there. I understand where you coming from that its an equal mass of power in RMS watts but you have to bear in mind the amount of amps that would be drawn from the battery. Im not talking about volts its the ampere drawage from the battery which would kill it. You can either be drawing out maybe 20 or 40 amps from one amplifier or you can double that by having two amplifiers.

And power caps are NOT a waste of money and i dont know how you could possibly say they are, they hold power for mass drains on the battery. You try driving down the road at night with your music blaring subs banging and whats happening ? Lights on the stereo, dashboard and headlights are dimming not to mention maybe having the heating on too - you not just draining the hell out of the battery but also the alternator. Wack a power cap on there and voila all them problems disappear......... and you tell me they are a waste of money?! ha ha ha ok.

Why go through the hassle of wiring a second battery or upgrading the alternator when £40 for a capcitor will do the same!

[nmt_oli]

And power caps are NOT a waste of money and i dont know how you could possibly say they are, they hold power for mass drains on the battery. You try driving down the road at night with your music blaring subs banging and whats happening ? Lights on the stereo, dashboard and headlights are dimming not to mention maybe having the heating on too - you not just draining the hell out of the battery but also the alternator. Wack a power cap on there and voila all them problems disappear......... and you tell me they are a waste of money?! ha ha ha ok.

Why go through the hassle of wiring a second battery or upgrading the alternator when £40 for a capcitor will do the same!

I'm afraid i fail to see how a power cap can suddenly prevent drain on the battery and alternator in a 'voila' kinda way.

A capacitor holds electrical charge, and can deliver it very fast when needed when compared to a battery, once discharged it needs to be charged again, this takes a LOT longer than the discharge period.

Unless correctly used they dont help that much at all, and will not in any way reduce power drain on the batt/alternator, they will just smooth it out somewhat.

Power caps are actully best used for the front speakers, rather than the subs as it prevents lack of power to these speakers, which is always mroe noticable.

[The enchanted broomstick]

I'm afraid i fail to see how a power cap can suddenly prevent drain on the battery and alternator in a 'voila' kinda way.

A capacitor holds electrical charge, and can deliver it very fast when needed when compared to a battery, once discharged it needs to be charged again, this takes a LOT longer than the discharge period.

Unless correctly used they dont help that much at all, and will not in any way reduce power drain on the batt/alternator, they will just smooth it out somewhat.

Power caps are actully best used for the front speakers, rather than the subs as it prevents lack of power to these speakers, which is always mroe noticable.

Ok so i would like to know where you get this information from? Have you actually personally tried any of these solutions or just going by internet pages and people's opinions? because i have actually tried and tested it all and have the results. If power caps were no good, why would they make them?! Its simple really, they make them because they do work.

[Fish-Finger-er]

yes once again, i see where your coming from on the amp front. but if hes using 2 small amps, compared to one big amp, both with the same combined total power output, then itll be the same. go back to your physics lessons in school,.

Watts = Volts x Amps

therefore watts/volts = amps.

so if you got a total output of 400watts rms.

400w/12v = 33.3amps.

and

200w/12v = 16.65 amps

+

200w/12v = 16.65 amps

16.65 amps + 16.65 amps = 33.3 amps.

therefore same draw. (note calculations wer done on pop tart packet so aint exact, but its close enough.)

wasnt referrin to the whole idea of havin 2 big amps vs 1 big amp, was talking about the difference between having the same power output from one or 2 amps. only difference is cost, wiring complexity etc, not total power output/battery draw.

as for power caps, they hold energy for such a small amount of time, its barely noticeable. and the time they take to charge up makes them not much use. aint sayin there completely useless, but would put my money in else where to my system, unless i was going for looks. in which case a power caps ok.

but they hold power to keep ur lights or the like on for about a second, its not like they store up ur unused energy all through the day, and let it out slowly over 10 hours during the night, its more like they discharge in a 1/4 second,then a 4 second charge period straight after, at which point the subs worse off than they wud be without them, as there losing a bit of available battery power as its going to be recharging the power cap.

[george_seamons]

Ok so i would like to know where you get this information from? Have you actually personally tried any of these solutions or just going by internet pages and people's opinions? because i have actually tried and tested it all and have the results. If power caps were no good, why would they make them?! Its simple really, they make them because they do work.

He's right Stu. They are shat.

All you need to do is wire a 10p capacitor inline with your headlights, and it will stop the dimming problem.

I'll have a look for the article that majorly disproved the power cap after work. It's an interesting read.

EDIT: Its not the one I was looking for...but it will do for the moment:

Power caps.....

Right a bit of info for you:

if you lights are dimming then you are drawing too much current from your charging system, that is your battery and alternator, and the voltage is dropping. Adding a CAP will not help, it may make things worse! caps are sold by retailers because they have a very good markup and can disguise the problem of light dimming but will put more strain on your battery and alt.

you alt makes the power (13.8V), you battery stores the power (12V) and your amp is using the power. providing you alt is makin more power than your amp is drawing you should get 13.8V at the amp power terminals. now when you amp draws more current than your alt can supply, the voltage drops from 13.8V, the extra power is taken from your battery which is at 12V! so you are now draining your battery and your alt cannot keep up. once you are drawing more power than you battery can supply the voltage drops below 12V and lights begin to dim! now if you voltage gets below 10.5V regularly things often start for fail.

A 1F cap will supply 1A of current for 1sec, so if you want 50A of current for you amp, after 1/50th of a sec your cap will have discharged (seriously simplified explanation there) and your alt will now have to power your amp AND recharge you cap putting even more strain on your battery and alt.

Edited August 22, 2006 by george_seamons