amp set ups

kev s

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hi this is my first post and i need a little help

i need some advice on how to set up 2 amps in my car, on my old system my 4 channel amp and my sub amp were bridgable, so basicly i had one power cable which went into a fused split box which then had one power cable going to the 4 channel amp and one going to the sub amp to power 2 subs, then the 2 amps were joined together by a rca cable then one rca cable from the 4 channel amp to the headunit

now my new 4 channel amp is not bridgable so how do i set these up? can i do it the same way as above?

the 4 channel amp ill be using is a directed audio a1004, not sure on which sub amp just yet but will be a directed/alpine etc.... and will be powering 2 subs


cheers kev
 
What headunit are you using? If aftermarket i always go for ones with 3 pre-outs (front/rear/sub) and run 3 leads to the back giving headunit control over the amps.

The directed audio a1004 does have a line out you can connect to your subs amp.
 
Hi Kev, welcome to the forum.

Please state what you have with model numbers
 
cheers guys

this is what i have

directed audio a1004 amp

Number of Channels4 RMS Power (4 ohms)90 watts x 4 channels RMS Power (2 ohms)125 watts x 4 channels RMS Power (1 ohm)Not Stable Bridged RMS PowerNot Bridgeable Total RMS Power Output500 watts Peak Power Output1000 watts Minimum Impedance Unbridged2 ohms Minimum Impedance BridgedN/A THD at Rated RMS Power1.0% Speaker Level InputsYes Preamp OutputsYes Built-in Crossover2-Way Butterworth/50 Hz - 500 Hz High-Pass Crossover FrequencyN/A Low-Pass Crossover FrequencyN/A Subsonic FilterVariable Signal-to-Noise Ratio>98 dB Channel SeparationN/A Bass BoostN/A Bass/Gain RemoteN/A Fan CooledN/A


2 jl audio w3v2 12in subs


Nominal Diameter: 12 inches (300 mm)
Continuous Power Handling: 300 Watts
Voice Coil: 2.25" diameter, 4-layer, Kapton former
Dual 2 ohm
Xmax (one-way, linear): 0.46"-0.51" (11.7-13.0 mm) depending on specific model
Sealed Enclosure Range: 1.00-1.50 cu.ft. (28.3-42.0 liters)
Ported Enclosure Range: 2.00-3.00 cu.ft. (57.0-85.0 liters)
VRCT Technology: YES
Elevated Frame Technology: YES

the headunit is alpine one with front, rear speaker and sub outputs

sub amp is undecided at the mo


cheers kev
 
I'm not sure what you are meaning with the configuration, sorry.

I'm assuming the directed amp is driving full range or components and that you will have a seperate amp to drive the subs. The bridging of an amp is the outputs to a speaker, effectively taking the left and right stereo outputs and making one large mono output to a sub. Generally you only bridge a sub output (although you can bridge a 4 channel into a 2 channel)

Both amps can be run as you do now, off one power feed with a splitter providing that suitable guage wire and appropriate fuse is used.

edit:
Ah just twigged... you have the 4 channel working as a preamp of sorts for the other...

How many speakers you driving? etc. If the pass through is more for convenience, you can get RCA splitter cables if fitting another set of RCA's is tricky.
 
the directed amp will be powering 4 speakers, 2 front and 2 rear, then another amp for the 2 subs

so i can run both amps off a the fused splitter box i have, on my old set up the amps were also bridged with a rca cable, now as the directed amp im gonna use is not bridgable what difference does this make?
 
Just to check, your 12w3 subs are they defiantly Dual 2Ohm and not Dual 4Ohm? There are 2 configurations for this sub.

If it is the Dual 2 then the amp to have is a Genesis Profile Sub. One of my friends runs the same subs as you in a sealed box. He has the Dual 2Ohm versions and wires both to 4 ohm (both 2Ohm coils wired in series) and then joins the 2 subs together giving a total load of 2Ohm. This means he can have the amp giving its maximum output of 550W RMS and has been able to hit 143 DB+ and thats in a sealed box!

If you can stretch to the Profile Sub Ultra i would recommend this as it will give you more overhead too. The Profile sub and be picked up on eBay from as little as £100.

As for bridging your amp you have no need, Run your power cable through the splitter as you always have (Minimum cable gauge 2-4 and Preferably 0Awg (Autoleads do a good kit for this)) You will then need 3 rca cables from your HU front and rear to the Directed and the sub to the Sub amp.

That should mean everything works as you want it to.

Hope that helps

Andy
 
cheers for the replies

not too sure on the subs ohm rating just yet as they havent arrived from the guy i bought them off

so i can set up everything exactly the same as my old set up and i dont have to bridge the amps, thats great:thumbsup::thumbsup:

cheers
 
Yep that's it, Just remember to make sure your wiring is up to the job, If it's not you could overload the power cable and set fire to your car!

What you need is this Autoleads 2000 Watt 2 Amplifier wiring kit on eBay, also, Terminals Cabling, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 15-Feb-09 21:17:11 GMT)

Expect to pay around £50 for this kit. This is what you will need for running your amps, it will give you all the power you need plus some extra for future upgrades. This is one of the most popular kits so have a hunt round for the best price, Also don't forget you NEED to upgrade the battery earth cable. I.e. run 1 new cable from the negative on the battery to the car chassis, without this you will still struggle for power and may get dimming lights and loss of punch with your bass.

Andy
 
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cheers

dont worry about the wiring, i have all my old wiring from my last install and its more than capable of running what i have now:thumbsup::thumbsup:
 
OK, hope everything works out well for you and let us all know how you get on when it's finished.

Andy
 
Tbh I'm not a fan of the alpine amps, It will do the job but at that price don't expect too much.

Also make sure you will be able to get a 2Ohm final load otherwise you will only have 300w available at best and thats not enough for 2 subs. Remember the RMS ratings on the amp are done at 14.4v and normally cars only manage 13.5-14v with the engine running.

Andy
 
cheers for the advice so far andy

subs arrived today and they are jl audio w3v2-d2 subs and are dual 2 ohm voice coil subs

been looking at the genesis profile sub amp and am just waiting for one to come up in my price range
 
Dual 2 Ohm is great! Just what you need,

Are they in a sealed or ported box?

When wiring them up you will need to (if you don't already know)

Join the - of one coil to the + of the other (joining the coils together) and should then be left with 1 + and 1 - connection. When testing this with a multi metre it should read around 3.5 -4.5 Ohm approx.

Then do the same with the other sub, this then means you should have 2 subs with a load of 4 Ohm each. When you connect them to the amp connect both - to the - terminal on the amp and both + to the +. This then means you're running the 2, 4 ohm loads in parallel and gives the amp the ideal 2 Ohm final load you want to get the most from it.

Once you get the amp tweaked correctly you should be very happy. If you find the x over freq is too high, give genesis a ring and ask if you can have some filters (the x over on the profile is done by little plug in filters) just find a freq you like and enjoy.

Andy
 
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cheers andy, i was gonna ask you about how to wire them up but you beat me to it lol

they will be in a sealed 18mm thick mdf box
 
Sounds good, if it's a double box that has 2 separate chambers drill some very large holes through the middle so as the 2 boxes become one. This will guarantee they are not in 2 separate sized enclosures.

Andy
 
Sounds good, if it's a double box that has 2 separate chambers drill some very large holes through the middle so as the 2 boxes become one. This will guarantee they are not in 2 separate sized enclosures.

Andy

Can i just ask why this is better? Just recently installed 2x 12" cerwin vega vmax subs in my car. They are both in single boxes next to each other joined with brackets. If its the same principal if i were to this what would be the difference?

Thanks
 
the box does have 2 seperate sealed chambers so ill get the drill out and take a large section out but leave around a inch all the way round to keep the strength in the box
 
Can i just ask why this is better? Just recently installed 2x 12" cerwin vega vmax subs in my car. They are both in single boxes next to each other joined with brackets. If its the same principal if i were to this what would be the difference?

Thanks


It's much better to have the subs sharing the same air space as i guarantees they are performing the same and even more so when they are run bridged as Kev is doing.

If you have 2 single boxes there isn't much you can do without buying another box. Also if you’re not running both subs from the same output on the amp, have you measured the outputs of the amps?

Andy
 
right sub box is ready after removing a large chunk of the centre section and resealing all the joins due to the poor job done by the factory

now whats the best sort of wire to use on the subs, just some decent gauge speaker wire? will be soldering all connections

now when i come to wiring the subs up is below the best way to go

2_2ohm_dvc_2ohm.gif



on the amp front im still waiting for a genesis sub amp to come up on ebay for a sensible price, the last one on there i bid upto £135 and still didnt hit the reserve and now the guy wants £200 buy it now for it

so i need some alternatives which will be upto the job of powering the subs but preferbly not going over my £100 budget
 
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Yep that diagram is spot on, If you want to go a touch futher fibreglassing the joins inside the box is a good idea for a really solid box.

You don't need to solder the ends as long as the speaker wire clamps are good.

As for an amp i'll have a look round and see what i can find that will push enough power @ 2 ohm.

Andy
 
Right, I have been having a look and TBH i am struggling to find anything within that budget,

If you can wait and find some extra cash the Genesis profile sub can be bought new for £269 from Car Audio Direct for car stereo, navigation and audiovisual electronics. which is a real bargain but way above your budget.

Amps to consider/look for would be

Alpine PDX 1.600 (if you can find a used one)
Alpine MRP M1000 (found this on eBay ALPINE MRP-M1000 on eBay, also Mono, Amplifiers, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 04-Mar-09 13:35:48 GMT) not a good avdert or the best amp but does deliver the power you require at the budget)

Other than them 2 and the profile sub I'm struggling to find anything within your budget that has enough power to run the 2 subs. You could run a smaller amp with less power; however you may not be happy with the volume and if the amp is clipping due to being incorrectly set you may kill the subs.

I'll keep thinking and let you know if i can find anything else for you.

Ideally you could do with a higher budget but that's not as easy as it sounds.

Hope that helps

Andy
 
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