Running two amps from one rca output

[lauriedatlen]

i waould like to run two or possible three amps to three subs but i have a head unit that has only one rca output. i can get splitter leads that can split the rca output but i was told the amps would sound crap if i did this. please could sum1 advise on this.

cheers

laurie

[bump]

you shoudn't have a problem with this. i know that epo runs split rca's.
http://www.maplin.co.uk/module.aspx?ModuleNo=9662&doy=19m6
that should solve your problem.

[epo]

yeah i do but i have noticed a bit of loss of power due to this so i am going to install a linedriver i think its called to cure this also i bought the splitters from motorworld

[Barnie@4D........WALES]

you shouldnt notice any loss of power, the gains will always match your headunits pre-out votage so even if theres a slight drop you will be able to compensate

the loss of power may be due to volage input from the battery, more amps = more current draw, measure your voltage at the amps inputs and youll see what your getting

[epo]

it deffo doesnt seem as powerfull \ loud me old hu had 2 pre outs :?

[Marc]

if your struggling for pre-outs i got a alpine head unit off www.bassjunkies.com for 150 with 3 pre-outs. its a great head unit will only try alpine first before i buy out else, really do like alpine :D

[Nick]

of course you notice a power loss.

the RCA is a set 2.0v max output sine wave (sometimes it's a bit bigger due to a better stereo)

this 2.0v power output will be divided by the two amps according to their impedance.

Thus, each amp would prehaps be amplifying a signal of half the power. which will lead the amp to have a tendenecy to premature clipping, depending how the amplifiers are made ( transistor, mosfet)

[epo]

of course you notice a power loss.

the RCA is a set 2.0v max output sine wave (sometimes it's a bit bigger due to a better stereo)

this 2.0v power output will be divided by the two amps according to their impedance.

Thus, each amp would prehaps be amplifying a signal of half the power. which will lead the amp to have a tendenecy to premature clipping, depending how the amplifiers are made ( transistor, mosfet)

yeah thought as much
that linedrive things suposed to cure this tho

[Barnie@4D........WALES]

of course you notice a power loss.

the RCA is a set 2.0v max output sine wave (sometimes it's a bit bigger due to a better stereo)

this 2.0v power output will be divided by the two amps according to their impedance.

Thus, each amp would prehaps be amplifying a signal of half the power. which will lead the amp to have a tendenecy to premature clipping, depending how the amplifiers are made ( transistor, mosfet)

not totaly true, will explain later

[Nick]

the RCA's output is limited

therefor when using more than one amp on the output, your going to be increasing the load on a limited voltage, it's not like the headunit is a powerpak lol. One factor stays the same, the other is inreasing.

[Barnie@4D........WALES]

would have replied soon but monitor blew up


the heaed units outpust only acts as a signal, so it doesnt matter of you have a higher voltage preout you amp will only put out the same if the gains are set up correctly as a lower voltage unit


the bast way to set up is on a scope, see if you can borrow one and set up on that

[Nick]

erm.

the amp, only amplifies the signal, lower input = lower oputput, it's all feedback related / biased related. to get the same output from a sytstem with a lower input, you'l have to crank the gain up higher, then you'l expirience easier saturation levels

And that is using both transistor amps and mosfet units.

[-tucny-]

the gain is designed for compensating for lost power between the hu and amp. its not designed to be used purely as a volume knob. every amp you buy will say this in the instructions, have a look.

so both arguments above are correct to some extent. yes you will loose some signal power but this can be compensated only to a certain limit by the gain. therefore after adding x amount of amps the singnal from the hu will be lowered to such a point that the gain cant compensate for this enough thus creating a loss of volume, which is when some form of preamp will be needed.