4x50w

howett · Post by **howett** » Mon Aug 01, 2005 10:52 pm

If a headunit is described as 4 x 50w. Will this work ok in a car with only speakers in the front?

razvwpolo · Post by **razvwpolo** » Tue Aug 02, 2005 12:20 am

yes it will which means the head unit will power 4x50watts or for example if you had a amp and 6x9 in the back you would have to put/add components to the front speakers in order to get full power from the speakers or you would only get the head unit power which is 4x50w.... if you look on the back of head unit they wiil be 2 phono inputs which are for the rear speakers but if you havnt got any you can add to that later ie 6x9...well i think so ha ha

Tigz · Post by **Tigz** » Tue Aug 02, 2005 8:35 am

razvwpolo wrote:yes it will which means the head unit will power 4x50watts or for example if you had a amp and 6x9 in the back you would have to put/add components to the front speakers in order to get full power from the speakers or you would only get the head unit power which is 4x50w.... if you look on the back of head unit they wiil be 2 phono inputs which are for the rear speakers but if you havnt got any you can add to that later ie 6x9...well i think so ha ha

What was that?

4x50w is normaly the max rateing.
Alpines '60w' internal head unit amps give around 17wrms.
If that is powering standard speakers then yes it will be fine.
They are pretty low powered/highly sensitive speakers so dont need loads of power to move them.

The "Inputs" are not imputs.
They are RCA Outputs.
This takes a low power signal from the headunit to an amplifier.

stuart_hatch · Post by **stuart_hatch** » Tue Aug 02, 2005 12:16 pm

See if you just run two speakers off the head unit, and fade the balance too them will that give 2x100w max?

polocoupcl · Post by **polocoupcl** » Tue Aug 02, 2005 8:25 pm

basically in a headunit you have a small four channel amplifier. each 'channel' will power one speaker with the stated power eg...50w if you was to only run two channels or 'two speakers' you would still only get 50w to each channel. My advice. Got yourself a good quality amp and components

the louder, the better!

stuart_hatch · Post by **stuart_hatch** » Tue Aug 02, 2005 10:59 pm

polocoupcl wrote:basically in a headunit you have a small four channel amplifier. each 'channel' will power one speaker with the stated power eg...50w if you was to only run two channels or 'two speakers' you would still only get 50w to each channel. My advice. Got yourself a good quality amp and components the louder, the better!

Which i have done, just thinking for my rear speakers (for surround sound for the dvd player)

Tahrey1043 · Post by **Tahrey1043** » Thu Aug 04, 2005 12:50 am

if i was running it with only two outputs connected i'd feel safer about the arrangement if i fadered the control all the way to the front (assuming thats where they are) just so the amp isnt trying to blat 50 watts at a connection that isnt there and overheating

if you want 2x100w you could bridge the connections ... maybe? im no electrician, i think it would work, connecting the left speaker to both FL and BL, the right to FR and BR, but who knows .... it might explode

be sure your speakers can handle this of course! and that you're not trying to drive them louder than the amp can handle, if their own rating is ample in comparison.

far better to save up for a second set of cans at the same time as saving for the head unit though, and enjoy the full output. particularly if the two speakers you're referring to are the ones already installed by VW, as they're likely to be quite poor and 50w will frankly be overkill for them. However, unless things in your car are still as bad as the state of play in a 1990 mk3, they should work fine as backup for a decent set of rears (better yet if you can swap them round??)

PS Tigz has a good point also, car speakers are usually only 4 ohm impedance, to a home stereo's 8 ohm or higher. Means they lack the same refinement (you wont notice tho! i cant...) but can produce more volume for the same power - so dont worry about it being loud enough. A 4x40 would do for most uses unless you want bleeding ears from the treble, or more importantly, ground shaking bass.
((put 4-ohms up front and 8s in the rear to hear the mismatch... lol))

bass mekanik · Post by **bass mekanik** » Fri Aug 05, 2005 12:22 am

stuart_hatch wrote:
polocoupcl wrote:basically in a headunit you have a small four channel amplifier. each 'channel' will power one speaker with the stated power eg...50w if you was to only run two channels or 'two speakers' you would still only get 50w to each channel. My advice. Got yourself a good quality amp and components the louder, the better!
Which i have done, just thinking for my rear speakers (for surround sound for the dvd player)

for proper surround sound in car you will need a centre channel and a 4.1/5.1 decoder as well. expensive.

Tahrey1043 wrote:if i was running it with only two outputs connected i'd feel safer about the arrangement if i fadered the control all the way to the front (assuming thats where they are) just so the amp isnt trying to blat 50 watts at a connection that isnt there and overheating

if you want 2x100w you could bridge the connections ... maybe? im no electrician, i think it would work, connecting the left speaker to both FL and BL, the right to FR and BR, but who knows .... it might explode

be sure your speakers can handle this of course! and that you're not trying to drive them louder than the amp can handle, if their own rating is ample in comparison.

far better to save up for a second set of cans at the same time as saving for the head unit though, and enjoy the full output. particularly if the two speakers you're referring to are the ones already installed by VW, as they're likely to be quite poor and 50w will frankly be overkill for them. However, unless things in your car are still as bad as the state of play in a 1990 mk3, they should work fine as backup for a decent set of rears (better yet if you can swap them round??)

PS Tigz has a good point also, car speakers are usually only 4 ohm impedance, to a home stereo's 8 ohm or higher. Means they lack the same refinement (you wont notice tho! i cant...) but can produce more volume for the same power - so dont worry about it being loud enough. A 4x40 would do for most uses unless you want bleeding ears from the treble, or more importantly, ground shaking bass.
((put 4-ohms up front and 8s in the rear to hear the mismatch... lol))

the ohmage is also the reason you WOULDNT be able to bridge the head unit amp.

when the channels are bridged each channel would see 2 ohms individually sharing the 4 ohm load. for this, the amp would have to be 2 ohm stable in stereo. there are VERY FEW head units that do this. pioneer did a range a few years back where a sub could be run off the bridged rear channels on on the head unit- but it was dropped, basically coz it was crap!

stuart_hatch · Post by **stuart_hatch** » Fri Aug 05, 2005 12:36 am

My h/u has dolby prologic built in, i suppose your right i would need a proper surround sound amp, but ive tried the h/u in my mums 306 and the surround is still quite good

Tahrey1043 · Post by **Tahrey1043** » Sat Aug 06, 2005 2:56 pm

prologic head unit?

i'd have some of that.....

my dvd player has an option to enable it when playing audio CDs thru it, and there's quite a few discs ive run across which have encoding "hidden" on them. niiice

are 5.1 decoders really that expensive any more then? even my Â£80 DVD player has one after all