can i power 2 x 400w speakers from my car radio's 4x50w amp?

Question

Hi-

I have got two 25cm coaxial speakers which state 400w max (100w nom) and an impedance of 4ohms. My car head unit states that it is 4x50w and my question is whether it will be ok to power these speakers from my head unit? I am running two smaller front door speakers with two of the channels from the amp so that leaves the two remaining channels at 50w each...

if i needed to add an amp, what kind of power rating should i be looking at?

Answer 1

Yes, but you obviously wouldn't get that amount of power from them. I'd say install a seperate amp to utilise their purpose.

Answer 2

Sure you can power the speakers but you'd only be getting 50 out of the 400 watts. Remember that the larger number is the max watt power. What you want to look at is the RMS (continuous power). Theortically, no speakers can ever continously produce sound at its max watt output, you'd blow your speakers in a short time.

An amp would provide more power to the speakers with putting stress on them as well as your head unit. "Concept" makes very good amps. I suggest a 90 watt x 4 channel amp to power your rear deck and door speakers.

hope this helps!

Answer 3

helo mate. i can tell you the same answer as d others but the truth is your battery is not that strong and u can loose power speccialy during the night. the best thing u can do is : buy a 400w amplifier or over,buy a large battery suply wire with about 3/4 metters long,and another one with the same legth black{neghative} and follow the instructions on the book provided inside the box of the amp. and make sure that when u connect the wires of the speakers you use+and negative correctly.if you follow this instructions you 'll hear your music much better,without taking the power from ur battery.

Answer 4

http://spkrbox1.spaces.msn.com/ for real "sound" advice.

Your system won't mean squat without a well designed box to put your subs in. Some manufacturers have recommendations as to dimensions of various types of boxes. It is best to find someone who builds boxes if you go with something other than a sealed box.

You should always match up RMS (Root Mean Square) watts of Subs and amp per channel as well as impedance's(resistances). When a sub has rating of 600 Watts MAX it really has an RMS rating of about 200 Watts RMS. RMS is the nominal wattage your most likely going to get out of it. Remember, a 200 Watts RMS amplifier has more power output than a 200 Watt MAX.


If your amp is rated at 4Ω don't subject it to 2Ω, it will fry.

Here is the formula for subs in parallel:

Z = 1 / (1/sub1 + 1/sub2 + 1/sub3 + ....)

For series, just add them up (sub1 + sub2 + ...).

You can mix and match these equations to get the right impedance required by your amp.

Example 1: Amp is 2 channel and rated at 4Ω, 4 subs @ 4Ω each. If I connect two in parallel and the other two in parallel and connect the two pairs in series, I would have a total impedance(resistance) of 4Ω. So to the amp, it's just one sub.

Example 2: Amp is rated 1Ω mono, 2 subs @ 4Ω each dual voice coil. If I connect two voice coils in parallel and the other two voice coils in series and connect the two subs in parallel, I would have a total impedance of 1.6Ω. Which would be perfect for a 1Ω stable mono amp.

You should use a capacitor as well.

Recommend for every 500 watts MAX you use a .5 Farad cap
Example: 1000 watts MAX - 1 Farad cap

You will also need what's called a "line level converter" if your stock head unit doesn't have RCA outputs or your amp doesn't have high-level inputs.

Try http://www.soundomain.com/shop you can find some really good deals, and this site is manufacturer certified. VERY IMPORTANT WHEN SHOPPING ON-LINE!!!

If you like I can send you some plans for reference. My plans are for a 4-th order band-pass bass box (A.K.A. bass-reflex) that holds two 12's.

Also included are java calculators you can use to figure parallel and series values given Ω values, tips on box building and types, calculating port diameter and length(if used), calculating box dimensions for types of boxes (sealed, wedge, cylindrical, etc.), materials needed and even how to make a jig for cutting perfect holes for your subs.

Just e-mail me [e-mail]

My system

Blaupunkt TSw1200 subs with a Sony Xplōd XM2200GTX.
My amp is 1200 watts (200 Watts RMS X 2), subs are 600 watts (200 Watts RMS) each, cap is 1.5 Farad

SPL is about 112 db each sub

Total cost(so far) = $410

Answer 5

25 cm? By converting that into inches, those are small speakers. For those to handle 400 watts in incredible. You should be fine running them off of your radio. The radio may state 50x4, but more realistically, the radio has an RMS output of about 18x4.

Answer 6

all that will happen is your stereo will sound quieter,, you could get a bigger amp.. and if the speaker says 400 max. 100 norm,. find out if it is RMS or PMPO... any amp rated at 100w RMS should be fine... you only ever get a problem if the amp is too powerfull for the speakers.... always look for RMS rated equipment,,

RMS: root mean square,, ie;continous power
PMPO: highest peak of the music at full whack....

Answer 7

yes and if 4x50 is more then enough for the average system... id you do not need a super loud bass system do not waste money on amps... if you want the extra kick buy a 4x400 amp (or 350 to be sure you want have distorsions when you play it loud!)

Answer 8

yeah - go for it and enjoy.
The clarity would be better too because the speakers can more than handle the wattage from the amp.

Answer 9

you could but i wouldnt give your radio long you realy need to get an amp about a 500w should do it

Answer 10

yes