Help to explain some basics?

[AJ]

Hi guys.

Can anyone help me explain this to a friend of mine. He has just bought a head unit that is 4x52W and he is looking at getting 400W 4 way 6x9's. I don't think he will need an amp but he's not so sure. Is there some conversion between what the head unit puts out and what the speakers need putting in when it comes to watts?

Also, can you explain the difference between 2 and 4 channel amps please?

Thanks.

[scarecrow]

That sounds like BS watts to me, I doubt any 6x9's actually make 400w and decent brands wouldn't claim it, so i'm just going to assume he's gone and bought sh*t.

In such a case then his headunit will be perfectly adequate in powering them, however better sound quality can be had from using an amp that outputs at a wattage closer to what the speakers are rated for.

2 channel amps output to 2 channels at x watts; ie. they can power left and right front speakers at x watts each, or they can power one subwoofer in bridged mode at 2x watts.

4 channel amps output to 4 channels at x watts; ie. they can power left and right, front and back speakers at x watts each, or they can power front left and front right each in bridged mode at 2x watts per speaker, or they can power left and right front speakers at x watts each, and a subwoofer in bridged mode at 2x watts.

Bridged mode effectivley joins the output of two channels.

[kid_dynamite]

Channels: literally one channel per speaker. A two channel amp can power two speakers. A four channel amp can power four speakers. Some amplifier channels can be 'bridged' turning two output channels into one (with more power). E.g. a four channel 200W amp (4x200W) may be able to be bridged to a 2x400W amp (supply 400W to two channels).

Note that headunits generally CANNOT be bridged.

I highly doubt those 400W speakers are actually 400W. They are usually marketed at the maximum possible output they can handle e.g. Pioneer TS-A1671s speakers (for example) are a 220W speaker, but that is max power they can hand;e for a short time. Their 'nominal' power rating is 35W, and a more correct representation of the capacity. So for that 4x52W headunit they would probably a bit small (if you are not using an amp).

If you choose to use an external amplifier you would be bypassing the headunit's internal amplifier.

//edit: crap! too slow!

[khunjeng]

i.e RMS is really the most important figure to look at for normal operation.

those speakers would fall apart at 400W RMS...they are most likely 70-80Wrms

[Dr_Jones]

And the head unit itself probably only does about 15wrms.

[khunjeng]

yep exactly...my head unit is 35w (peak) per ch ~15Wrms I guess. some pioneer double din pice of junk that cost the rpevious owner 1k...I have speakers from Jaycar that are rated at 80w RMS...its still too powerful for my car...

I find...and ppl may argue..u need an amp for either sh*t quality speakers and/or a Sub...def. for a sub. and I have look at a lot of big brand name speakers that are sh*t quality...with sh*t sensitivity ratings...hence u need an amp to drive them.

If your just running some std 6x9s...don't bother with the amp...its will be good enough. U will get a gain from the amp...but in my opinion the gain isn't worth it for a normal setup. Not to mention all the extra dramas with install and the alternator (potentially).

KJ

[sublime19]

yep and if it's "400W", thats the maximum amounts of watts, normally he'd be running at a third of that

[AJ]

Thanks guys, that really helped out!

[Robbie]

My pioneer 6x9 (TS-A6972E) specs are :
max music power:400w
nominal power: 80W

[I8A4RE]

My pioneer 6x9 (TS-A6972E) specs are :
max music power:400w
nominal power: 80W

Dude this thread is about 4yrs old

[Robbie]

yeah, i realised after...