Question about car amps

[tontod]

I bought a pair of JBL speakers ($50), I think peak power handling is 70W, 92dB sensitivity. I was thinking of hooking up an amp to those. The guy that installed the speakers says that I wont be able to install an amp because if I do I'll blow the speakers. Is that true? Can I get a low end amp that wont blow those speakers? I'm not looking to spend a fortune here. At least those speakers are better than factory default ones.

 

[Spoooon]

You can install an amp and not blow the speakers. Get an amp that matches the RMS rating of your speakers. And read up on clipping, etc.

 

[tontod]

Ok, so the rms of the amps has to be equal to or less than that of the speakers, right?

 

[divinemartyr]

With speakers that only handle 70 watts max, you really shouldn't be putting an amp on them, your installer was telling you what's best for the speakers. Use your deck's power (generally between 8-30 watts RMS). That's really about all the speakers should be able to handle if they're maxing at 70 watts. RMS is generally about HALF what the peak power is, so if an amp is rated for 25 watts RMS, it will probably peak at 50-60 watts, meaning you'd be very close to the speakers power rating even then.

You really COULD find an amp that would power these speakers without blowing them, but I can guarantee you that it won't be worth the money you spend on the amp. Cheap speakers can only be made to sound so good. Buy yourself some better speakers first, THEN get your amp.

dm

 

[DonNiggera]

if that's 70W RMS, and you get a 50-60w RMS amp for it, then you would have a very low chance of blowing them. But get a high quality 50-60w RMS amp, not no pyramid crap.

 

[divinemartyr]

<< if that's 70W RMS >>



You must have missed this part:



<< I think peak power handling is 70W >>



These speakers weren't really intended to have a power amp on them, stock power from a deck will probably be more than sufficient for these speakers.

dm

 

[tontod]

Yeah, its around 70W-80W peak.

 

[kcklla]

How many Wts does your deck put out?
I doubt you would need an amp

 

[tontod]

Deck puts out 19W RMS, 50W peak (per channel).

 

[Emulex]

yeah thats fine.

a decent 50x4 amp would destroy those speakers. I run pioneer compression horn 6x9 3 way's and my 50x4 pushes them near the limits even though pioneer rates them up to 200watts peak.

remember more power isn't necessarily better, cleaner will always prevail in audio.

25 watts rms of clear power is 10x better than 250watts of pyramid distortion

 

[tontod]

I have this head unit.

Edit: So when i see the wattage rating for a deck, its usually rated in RMS not peak, right?

 

[divinemartyr]

<< So when i see the wattage rating for a deck, its usually rated in RMS not peak, right? >>



No, if the deck says 50x4 then it's 50 watts max, probably anywhere from 15-25 RMS (Root means sqaured, or AVERAGE wattage). The RMS is the TRUE watts of the deck but because of the way advertising goes these days, they can advertise that as 50x4. Your deck is MORE than enough for the speakers you have. If you want an amp to power some speakers, you're going to have to get some speakers which handle at least 150 watts peak.

dm

 

[tontod]

I meant to ask that when you see power ratings for an amp, they're rated at RMS or peak?

 

[divinemartyr]

<< I meant to ask that when you see power ratings for an amp, they're rated at RMS or peak? >>



Companies which market great products (high end) will tell you BOTH the RMS and max power ratings. Generally companies like Jensen, Pyramid, Malibu, or other brands like you'll see in Best Buy and other lo-fi stores, will show the amp's MAX power, so if it says 400 WATTS!! It might be 100x4, but the actual RMS is probably somewhere around 20x4. When they do this they're also assuming that your car is always going to be running at 14.4 volts, rather than the standard average of around 12.5 volts. This is as much as a 60% increase in useable amplifier watts! My car runs at about 15 volts somehow, but most on average do not.

If you look closer at specs, reputable manufacturers will list it like this:

25x4 watts RMS @ 12.5 volts
40x4 watts RMS @ 14.4 volts

There are voltage regulators out there which can increase your car's voltage to always be 14 or 16 volts, depending on how much you want to get out of your audio equipment, but this is a long way off from where you're at it looks like.

If a company doesn't specifically list RMS next to the power rating, it's MORE THAN LIKELY a max power rating. Look for full specs whenever possible.

dm