Sub/amp question

I have said it before and I will say it again.

Read this.

http://www.bcae1.com/

It has EVERYTHING you need to know, and more.

 

Power handling of a subwoofer depends largely on the enclosure it's in. That being said, if you follow the specs that JL gives you should be just fine.

Never seen that before, looks good.

 

Cool thanks man

 

This actually irritates me because if you are directing this at me (which obviously you are with the last couple sentences), then you're talking shit on something you obviously only spent one half ass second of reading.
From reading this above, it's clear without a doubt that my basic points of interest for this guy went totally over your head to start with.

Meanwhile, I'm not gonna copy and paste shit in here as though I'm trying to teach the guy to become some electrical engineer....My posts were strictly to help an amp newbie find his way through the store a little better, because I've been there done that a lot more than just once since 1987.

 

Anybody who doesn't understand this must have a head like a brick. It's basic truth that can't be argued with.

And it has zero to do with the Bugatti analogy! Zero.

 

Anybody building a system should stay away from amps that will "max out" before the speakers do! Simple logic. Don't build a system and then under power everything with Mickey mouse amps with big bullshit wattage numbers on the box.

You get what you pay for <----- more basic logic that is impossible to argue with.

 

Now, go google "underpowering a speaker"


Lock thread

 

I actually haven't read a single one of your posts to be honest. The OP mentioned that he was thought he'd need "at least" a certain amount of power. Generally that comment comes when someone has been told they can harm a speaker by not sending it enough power. So don't get your panties in a bunch as none of it was directed at you or really anyone else for that matter.

I wrote a post/thread on power clipping and thermal limits of voice coils that is floating around here somewhere. It explains (in detail) why you'll never hurt a speaker by not sending it enough power. I own an oscilloscope for a reason.

I'm just trying to help the guy get what he needs. In my personal opinion I think he'd have been much happier with the PDX5 or the Kenwood XR5s. Both are one amp solutions that fit under the seats with plenty of poewer; why complicate things?

 

Yea, you don't want an under powering amp. You are someone who needs a good amp that won't run out of breath before the speakers do! Save a few pay checks and Stay away from the hype.

Besides, what is your personal, realistic budget for an amp anyway??

 

ive already bought one amp as i said earlier for my 13tw5 jl sub coming in next week, sub says it will handle 600 watts so i decided to go with a 600watt mono amp, which now sounds like im gonna underpower it and i have no real budget but i dont wanna go to audio shows with it so im not trying to showboat the hell out of this project, im just looking for something that will power all my speakers, so im guessing a 4 channel 500 watt amp would be good since all my speakers have a 100 rms rating ... dammit my brain hurts i work on electrical almost everyday but not the wattage side of things argh lol

 

If I may interject - I think the issue of debate here with not sending enough power to speaker is related more to the volume question. Sending low amounts of power to a speaker will not hurt it, which I think everyone agrees with. The problem comes when you have, for example, a set of 100W RMS speakers powered by a 25W RMS amp and decide you want to crank it loud. With the lower powered amp, you could send it into clipping at max volume, without coming close to the RMS rating of the speaker.

Now, power that same 100W RMS speaker with a 100W or 125W RMS amp and then decide to crank it...you could exceed the volume level generated in the previous scenario without sending the amp into clipping,,,in fact you may still not be approaching the RMS rating of the speaker. However, even the higher powered amp can be clipped at max volume.

The higher powered amp would allow you to drive the speakers at a higher volume with a lower risk of clipping/speaker damage.

I'm not an audio expert or electrical engineer - but I think this explains the disagreement. If I'm wrong - don't hesitate to educate me as I don't want to be misinformed myself.

 

you know what ill just message you blkturbo i dont wanna cause any disputes

 

Mike686 - read my above post - it may (if my thinking is accurate) clear up some items.

 

You're exactly right. That's pretty much what I wrote up explaining clipping in another thread.

The problem is people think they HAVE to get a 100RMS amp to match their 100RMS speakers. Truth is that they'll never listen to them that loud. 75RMS is MORE than adequate for loud listening levels. I don't think I've ever maxed out an amp on door speakers.

The market is tricking you into buying crap you don't need. I build home speakers (as well as car audio) and you know what I've been running my home audio towers on for the last year? A 10watt x2 amp. Yep, ten watts of power is more than enough to get my towers to ear splitting levels in my living room. If you think you NEED over 50 watts in the tiny cab of your truck you're out of your mind.


That being said, I'll be totally forthcoming when I say that I spent decent coin on a JL Audio HD900/5 amplifier about a year and a half ago. At the time the Kenwood XR5s didn't exist and the PDX5 still had noise issues. I bought the JL because it made more power than I needed and had the flexibility of impedance options meaning I could run a 4 or 2ohm speaker and get the same power. That and it was the size of a text book meant it was exactly what I needed.

 

I have a 5 channel amp, 1st n second channel are for the front. 3rd n forth r back speakers, and fifth is the sub. No problems so far. Having one saves space but it deffinatley heats up after a long ride. The first four are adjustable, and fifth is seperate which is nice.

If you get seperate amps doesnt matter the brand, its interchangable. try ebay n craigslist but research before you buy, ive seen alotta gimmicks!

 

One little detail I would like to throw in here (if it matters or makes any difference to anyone) is that "volume" has nothing to do with my posts. In fact, the volume knob on the radio has been the furthest thing from my mind in this thread.

Whenever and wherever I said "under powering", I wasn't referring to the volume being set low. I've been meaning that when the amp reaches it's fullest potential - running out of steam....whereas, the speakers are waiting to handle more power.

This all can get hard to verbalize I guess. So I will use my system as an example:
I know for a fact that my jl audio amps are much stronger than my speakers. Therefore, the gains on my amps are turned down to about 1/2 way! This is what I mean buying an amp that's considered overpowering. I can easily max out my speakers while using only 1/2 the amp's power.

 

I just read this post! Yes, this is exactly what I've been meaning and with this, if I continue to be wrong in anyones eyes....that's fine by me, because regardless, I will go to my grave being happier pushing a system with too much amp rather than too little

 

so i cant really get the pdx5 because the amp will be under powering my speakers and sub i know that the jl sub is 600 watt rms which by reading isnt accurate but the pdx5 is saying their rating for the mono side is only 300 watt so i know this is confusing but the sub will be underpowered correct?

 

Yes, you CAN use the PDX-5. You can also feed the sub more power, or less. After you complete the install you need to tune the system and set the gains and see what volume level you start to hear distortion in the speakers.

You could say that by having a mega power amp, you run less of a risk of clipping at the desired volume. Look at the JL web site, the "optimum" wattage for the sub is 250. Granted the PDX-5 is 300 RMS, so most of the time you will be driving significantly less than that.

One very important thing to note is the volume observed. By going from the PDX-5 (300 RMS) vs the other amp (assume 600W RMS) is a doubling of the power. With that doubling of power you will get only a 3dB increase of sound pressure level - some people (not all) may not even be able to distinguish a difference of 3dB.

So yes, you can go with the PDX-5 or the other amp. Bottom line is an improper install, or not paying attention to what the system is telling you can cause problems with either.

 

Well in this discussion, "cant" is a strong word.

That amp is an alpine amp with decent numbers so your system will sound clean I'm sure. Now, if you want this sort of detailed info and opinions, then let's focus in even greater detail what is is you want from your system.....so, that people in here or wherever can tell you more about what can and can't be done.

You said you want it loud, but you're not trying to compete in audio competitions.

So, what's important to you? Killer ass bass that can be heard from blocks away? Or really clean highs that you can hear just as clean from across the street? Maybe just normal, tight hitting bass that you don't need your friends to hear from blocks away?

Once everyone hones in on those details, you can more clearly be told what can and can't be done/purchased.
Because up to this point, I think your thread is still stuck in the numeric value of everything and the general opinions of the mass public

For me personally, I prefer a 2 amp setup managed by a nice preamp. Amp for highs and an amp for lows. But as you know, besides personal preference as I asked in the above paragraph, there's the limitations of vehicle size and your wallet.