Amp selection with 2 6x9s and a sub?

[SpaceYam]

Ok, well here's the situation:

I have 2x 200w Sony Xplod 3ways, and a dual voice coil 500w (1000w max) (ha!) 10" BOSS sub. I'm guessing I'll need a four channel amp and a two channel amp? Ie. the 4 channel amp to power the sub with the bridged channels, and the 2 channel amp to power the 6x9s?

If I'm right, then I need to know - what would be the best value for money amplifiers I can get? I'm not out there to deafen myself, I just want good sound quality that isn't going to blow itself up after 2 weeks. I do understand the importance of good quality wiring, etc, so that's not a problem for me, it's just a matter of choosing the right amps.

And then, where is the best place to get amps from? There's a Jaycar near me, but they don't have much at all to choose from, there's also a couple of Dick Smiths, AutoPro, Autobarn, Supercheap and a couple of Repcos.

Last question - I want to semi-permanently secure my sub in it's enclosure (I have a friend who's going to make me an enclosure when I get dimensions) in the middle of the boot behind the centre seat with the speaker facing the front, ie. so if you open the middle seat, you can see the speaker there. Is the easiest way to do that with those good old bungee cords and a bit of foam or something to eliminate vibrations?

Thanks guys!

 

[Tasmaniak]

BUNGEE CORD IS NOT APPROPRIATE. Use brackets that are easily accesible. Now with that out of the way.....

You could simply use a 4 channel amp or 2 channel amps. A dual voice coil sub wired to two channels only (amp must be bridged) will produce a 2ohm load on the amplifier. Unless it is a uber cheap amp it will be just fine giving you plenty of power to drive the sub. You could also ideally use a monoblock amp for the sub and another 2channel amp for the 6x9's

 

[SpaceYam]

I've never heard of a monoblock amp before, I'm assuming that they're designed for driving subs? Also, I'm guessing the second voice coil on the sub is only really necessary if you want to get a LOT more power or something? I was never quite sure how/why they worked since there's only one speaker and I was thinking that differences in the audio signals between each coil might cause distortions.

 

[Tasmaniak]

Either way you choose you would bridge the amplifier to give you exactly the same signal going in.

A Monoblock amp is primarily designed for subs yes, they are a SINGLE channel amplifier.

If you don't use the second voice coil, whats the point of owning it in the start?

 

[Jeff T]

From what I understand, the most economical option would be to buy a 4ch amp. Then use two channels to run the 6x9s, and bridge the remaining two channels to run the sub.

There seems to be a lot of buzz around about the new Jaycar amps, and they have a reputation of being good quality and great value.

This year's model is just coming out, have a look at their website. The 4x100W goes for $300.

 

[Tasmaniak]

The 4ch amp will struggle to deliver enough for the sub, plus underpowering speakers is a dangerous idea, almost as much as overpowering a speaker.

 

[SpaceYam]

Ok, I'm a little confused here:

To drive the TWO voice coils, you would need four channels in total? That is, two bridged channels. So I'll need a total of six channels - four for the sub and two for the speakers. Have I got something wrong? I may be getting a little muddled up.

 

[Tasmaniak]

Two power the two voice coils you need one channel.

Whether you get this one channel from bridging two channels together or simply using a monoamp it doesn't matter. But you only need ONE channel.

Quick explanation..hopefully, I usually tend to draw them out a little.

(+) from amp goes to (+) on the first coil. then the (+) on the first coil goes to (+) on the second. You do the exact same thing with the (-) terminals as well. Doig it this way presents the amplifier with a 2ohm load if they are 4ohm coils. If they are 8ohm coils then they will present a 4ohm load. IF (heaven forbid) they are 2ohm coils then this method will present a 1ohm load, which is usely a little too much load on a lot of amplifiers.

 

[SpaceYam]

Wow, don't I feel like a complete git? I didn't even THINK of doing that :bop:

The sub says it's "dual 4 ohm" so I'm guessing that's 4 ohms/coil which would make the total loud 2 ohms. Fair enough! I'm really keen to get this amp happening now . Thanks for the help. I'm just having a look at the amps on the Jaycar site now, they've also got an amp which "helps to power those difficult 1 ohm loads", not that that's really significant for me .

Thanks very much for the help.

Now, I'm not sure how soon I can do the sound system in my car, but the one last thing I want to confirm (since it's probable I'll be doing the interior before the sound) is what wires I need to run from the head unit to the boot. I'm going to make my own cables being as I'd rather do the work myself and save a LOT of money, but without actually having a look at anything, I'm pretty sure I need two nice fat shielded audio cables with RCA connectors - ie. one cable for left, one for right. I know I'll need cables for getting power to the amp as well, exactly what do I need for that?

 

[HSV VN]

you'll need a remote turnon wire/lead, that only needs to be thin - basically lets your deck know it's there
you'll also need a power wire from Amp to Battery Terminal (+), lower "gauge" the better.
finally, you'll need an Earth from your Amp (also needs to be thick), and ground/attach that to a screw or something inside your boot (assuming thats where your amp is going), but make sure that screw is actually touching the shell of the car.
Goodluck.