Can Anyone Help?

[Wayne]

I have bought a subwoofer, just a standard 12" ripspeed sub in a boom box, on the cheap of course.

Now im wanting to link everything up, but i come to a bit of confusion when it comes to the amp.

I have an alpine stereo 4x 45, 2 front standard speakers, 2 rear Sony 6 x 9's in the parcel shelf. What channel amp do I need, and how can i get the best results, i.e. running the 6x9's and subwoofer on the amp, or the subwoofer alone.

Any help would be great guys, thanks.

Wayne

 

[Britto_1.3Si]

if you want one just for your sub you want a mono block amp prefferably class D as that has better circuitry and can push the sub harder, if you want to run your 6X9's and sub on same amp you will need a 4 channel amp what i did when i didnt know what to do is i emailed bass-junkies.com as they know there stuff !!! its better to put all of your front and back speakers through a 4 channel amp and sub through a mono class D AMAZING results thats how mine is set up

 

[Retepetsir]

if you want one just for your sub you want a mono block amp prefferably class D as that has better circuitry and can push the sub harder, if you want to run your 6X9's and sub on same amp you will need a 4 channel amp what i did when i didnt know what to do is i emailed bass-junkies.com as they know there stuff !!! its better to put all of your front and back speakers through a 4 channel amp and sub through a mono class D AMAZING results thats how mine is set up

From my experiance, Bass Monkies know naff all.

Now 'ideally' you'd want uprated aftermarket speakers in the front of the car, powered off an external amplifier. However, thats not possible in your case.

With your current setup, I'd just go with a simple 4-channel amplifier. Use two channels bridged into 1 to run the subwoofer, and the other 2 channels to power the 6x9's (ideally you'd use it to power the fronts, but as yours are standard, its probably not a good idea). Then just run the fronts from the headunit.

Otherwise, if you can, upgrade the front speakers, then use the same 4-channel amp and use the 2 channels to run those instead of the rear 6x9's (run these from the headunit). Your sitting in the front of the car after all, which is where you want most of the power to be.

You'll then just need an 8awg or 4awg wiring kit to connect up the amp.

 

[andrewb150]

If you want to do things on the cheap your best bet is to buy a 2 channel amp and run the subwoofer bridged over the two channels. If your HU does not have a dedicated subwoofer output where you can vary/limit the output frequencies then you will need to make sure the two channel amp has a variable crossover built in.

If you are feeling rich and want the best then I agree with Britto_1.3Si a Mono Amp is the way to go as they are designed to be used with a subwoofer. Then you should upgrade your front speakers and power both the front and back off one 4 channel amp or two 2 channel amps (better IMO).

However your HU will power the front and rears fine for now at 45wpc RMS. So if I was you Id buy an amp for the sub now and see if you are happy with the sound from the fronts and rears once the sub is installed.

Dont forget that installing a sub means that you no longer need to output all the low frequencies to the front and rear speakers allowing you to go louder without distortion (especially if not using component speakers) while also being able to fine tune the sound more to your liking.

Ive found www.caraudiocentre.co.uk very reasonable and you have more 'come back' with them if you get into bother than with most cheaper ebay sellers.

Im not saying that a 4 channel amp would not work for powering rears and a subwoofer, but...

- has anyone had any real success doing this?
- Can anyone recommend it?

I guess as long as the amp has two separate sets of phono inputs (in this case for rear and sub) and independant gain & volume levels for each input. It could be a good compromise if space is a serious issue or if one 4 channel amp can be obtained at a significant saving when compared to two 2 channel amps.

 

[Retepetsir]

If you want to do things on the cheap your best bet is to buy a 2 channel amp and run the subwoofer bridged over the two channels. If your HU does not have a dedicated subwoofer output where you can vary/limit the output frequencies then you will need to make sure the two channel amp has a variable crossover built in.

If you are feeling rich and want the best then I agree with Britto_1.3Si a Mono Amp is the way to go as they are designed to be used with a subwoofer. Then you should upgrade your front speakers and power both the front and back off one 4 channel amp or two 2 channel amps (better IMO).

However your HU will power the front and rears fine for now at 45wpc RMS. So if I was you Id buy an amp for the sub now and see if you are happy with the sound from the fronts and rears once the sub is installed.

Dont forget that installing a sub means that you no longer need to output all the low frequencies to the front and rear speakers allowing you to go louder without distortion (especially if not using component speakers) while also being able to fine tune the sound more to your liking.

Ive found www.caraudiocentre.co.uk very reasonable and you have more 'come back' with them if you get into bother than with most cheaper ebay sellers.

Im not saying that a 4 channel amp would not work for powering rears and a subwoofer, but...

- has anyone had any real success doing this?
- Can anyone recommend it?

I guess as long as the amp has two separate sets of phono inputs (in this case for rear and sub) and independant gain & volume levels for each input. It could be a good compromise if space is a serious issue or if one 4 channel amp can be obtained at a significant saving when compared to two 2 channel amps.

Most 4-channel amps are also designed to be used (bridged) for a subwoofer, they tend to be Class AB after all, which sound better than Class D.

Also, no headunit is 45wrms, that is peak value. They are more like 10-15wrms at best, so done expect much from them.

And yes I've had much success with that type of setup, its the best value setup around, and easiest to wire up (only one amp). Ideally you want two channels bridged for the sub and then use the spare 2 channels to power a set of front components.

I'm using a meaty 5-channel amp (4 class AB channels plus dedicated class D subwoofer channel), giving the fronts 2 x 150wrms bridged and the subwoofer 1 x 600wrms into 2ohm. I'm sure at least a couple of people from the MSC can back me up with how decent it sounds .

One 4-channel up will be cheaper than 2 decent amps, and will also save on wiring (no distribution blocks, etc).

www.caraudiodirect.com are my choice of supplier, and check out www.talkaudio.co.uk/vbb for the best car audio forums in the country

 

[andrewb150]

Cheers for the reply Retepetsir, I knew someone would comment on my 45wrms HU thing, but Wayne wasnt that specific and at least it got a reply!!

Im sure your setup's sweet and I agree 15wrms would be a bit weak, Some HU's must be louder than that. I hate manufactures going on about 1,000,000W MPO

www.caraudiodirect.com are very good but it depresses me abit when some of their amps cost more than my car like the Steg Masterstroke MSK3000 a snip at just under £3,000.

I thought Class D was best for subwoofer due to its efficiency and Class AB The best of both worlds with good efficiency and better high frequency reproduction (less distortion). Although after a quick google of the subject it seems that alot of people are saying that they prefer/use Class AB.

At the end of the day this is really a therotical discussion as you can get good amps and bad amps irrellevant of class. The overall sound depending upon so many variables (speakers, environment, input, cabling, etc).

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Check out http://www.audiodesignline.com/howto/177102531 for anyone wanting a brief explaniation between the different types of amp classes

 

[Retepetsir]

Class AB tends to sound better, but Class D is more efficient (less current/amps drawn), hence why Class D tends to be used for bigger power (i.e. subs).

I'm looking at swapping to a Class AB amp for my subwoofer now, as SQ is my aim