New speakers first or amp first?

I going to add an amp that will I fear might be too powerful for my car's factory speakers.  Will also be adding new speakers that will not be supplied enough power by my car's factory radio.

I will need to do one at time, possibly weeks apart.  I'd prefer to do the amp first, that way the wires for the new speaker will be there ready when I do the speakers. 

Since, if I understand correctly (and contrary to what many believe), it is UNDERPOWERING speakers that cause damage, that would be the way to go?   I can always turn down the gain on my amp to keep from blowing out the factory speakers and even if that doesn't work I'd be putting in new speakers after that anyway.

Audiobass is right on.  The "underpowering" thing is one of the great horrible myths of car audio. 

My answer is going to be one that you'll hate, but one that some of you won't be surprised by; that is: it depends.

What shape are your current speakers in?

IF they are in good shape, THEN it might be good to buy the amplifier now if all you're looking for is more distortion free volume. 

Why?  Because most 4-channel amplifiers have high pass crossovers built in.  A quality and correctly set high pass crossover will greatly increase the power handling and sound quality of your stock speakers.

That isn't what I would do first, however.  Here's my priority list / guide in car audio budget system design:  (assuming nothing factory is broken or complete junk)

1) Subwoofer / Subwoofer Amplifier!

      This is the number one best addition you can make right away from a stock system.  Why?  Because it actually adds frequencies to your stereo that you are unable to hear unless you have it.  Most people push their car stereos to distortion / blowing / etc. because their current system doesn't have enough emotion or completeness.  So, what do they do? They jack up the bass and they jack up the volume.  This is what makes factory systems sound like complete junk.  Improper use.  By getting a subwoofer you can add the emotion and frequencies WITHOUT abusing your mids.  You may say, "subwoofers are only for high school kids," but they aren't.  You don't need the 2 12" chrome junk pair from Best Buy to add some bass.  A single unflashy woofer in a small box with small power will add quite a bit to a factory system.

Tip:   Buy a 4-channel amplifier at this stage.  You can bridge 2 of the channels to the subwoofer and use the other 2 for the front stage.  Budget system design at its best.

2) Head Unit

      Get yourself a good source.  A decent head unit, while a poor excuse for an amplifier, can add significant power and clarity to your factory speakers.  Most new head units also feature high pass adjustable crossovers.  Look for this feature if upgrading in steps.  Also look for one with three sets of pre-outs, one for the sub, front, and rear. 

3) Front Speakers

Now that you have OK head unit power and won't be abusing the speakers (because the subwoofer will provide the punch), it is finally time for the most important upgrade.  Speakers.  Plan to spend as much money as possible on the front stage.  This is where 90% of your system sound will be shaped.  Let your ears guide your pocket when auditioning speakers.  Bring your own music.  Pay attention to the installation.  Get a good seal around the speaker.  Make sure the baffle is as solid and leak free as possible.

4) Additional Amplifiers

These should be easy to implement since you have all the other equipment now.  Just make sure you have large enough power wire run to the amplifier's location and you're ready to go.  My number one piece of advice for amplifiers:  if it seems too good to be true, it probably is.  Seriously, be suspicious about amplifiers that give way too many watts for the money.  Unfortunately, demoing amplifiers is difficult.  To some extent you'll need to go off manufacturer reputation.  Ask here about amplifier brands folks respect.  If professionals respect a brand, the brand probably rates its amplifiers honestly and doesn't have serious reliability issues.  Shoot for an amplifier with RMS power anywhere UNDER the RMS power of whatever speaker or subwoofer you plan to drive.

5)  Everything else. 

Priusguy wrote:

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How would such distortion and thermal abuse occur?

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Distortion and thermal abuse happens when people (idiots?) fly off the handle with the volume or bass knobs and push their amplifier into severe clipping.  If your speaker's power handling capability is close to the rms output of the amplifier, then your speaker will eventually go buh bye. 

See https://www.bcae1.com/    ---> the page on "Too Little Power"

Priusguy wrote:

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Ok, but please keep in mind when responding what my question is really about.

I'm definitely replacing both the amp and all the speakers. Have already purchased a Kenwood 8542 and Infinity components for the front and three ways for the rear passenger (no subwoofer is planned.)

I was planning to do the amp first, based on both what's more practical with the wiring and b/c of that "myth" that underpowering, not overpowering (which I THOUGHT was the myth) is what blows speakers.

So my question is whether even though my factory speakers were not designed to handle the power the Kenwood is capable of putting out, will it be ok to do the amp first as long as I set all the levels on everything low until I replace the speakers. And am I correct no big deal anyway b/c worst case would be blown speakers I've already bought replacements for?

Thanks.

capable

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Yes. I already answered this at the top of my lengthy reply.  If you take care with the volume control, gain, and crossover, you won't have a problem.

Basically, unless you're careless, you should NEVER damage speakers - regardless of whether you run with 1 watt of 10,000 watts.

kfr

kfr01, you have written a great response to the question "New speakers first or amp first?".  Well done!  Here's hoping it gets the readership it deserves.  And I agree with your answer and learn continually from your logical mind.

Priusguy, try to put it (the post) into the context of your unique needs.  It may not apply 100% to your needs, but it does apply and you can benefit from the advise.  I take it you haven't gotten to the page on "Too Little Power" yet in your reading?  lol

Francious70 wrote:

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kfr01, don't you think a good solid front stage should be the first thing done, because the the sub/amp selection really depends on what's going on up front.

Paul

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Every system is different and should be approached differently.  Usually a HU, and a cheap sub/amp set up is a good start if the speakers are still playing fine.

In responce to the original post, i would say amp first.  Like before, once you hear distortion back the volume down a few notches and don't go past that for a max and you should not have a problem.  You will find the volume of your system will not increase much since your speakers cannot handle much in the first place.

Francious:  IF a person is going to complete a full system and has the budget to do it right, then yes, the front stage is #1.  No doubt.  I 100% agree that the front stage is the most important part of a system.

However, for someone on a budget, building a system step-by-step, I think a sub is the single best addition a new car audio person can make.

The best front stage in the world is going to be abused by most car audio folk w/o a sub to handle the lows.

I think it's time I add my 2 cents in here....eek!

Ultimately.....don't install anything until you have everything! But I understand the itchy sidecutter hand completly. I personally feel that you should replace the speakers first. This will increase your SQ, but it will not raise your volume by anything, in fact it could actually LOWER your volume....how so you ask? Efficiency, OEM speakers are usually high efficiency speakers, now, as you raise your efficiency you also raise/lift your lower frequency handling ability, as such a HE speaker will not go as low. HE speakers take very little power to get high volume, but they sound like A$$. Hence why it takes so much power to drive a subwoofer. To deliver such low notes, they need to be low efficiency. So by replacing these speakers, you will slightly lower your volume because they handle the lower notes better then what your OEM speakers will. But, never fear, because once that amp hits them, you will get it all back plus more!!!! WOOHOO!!!

Now my thoughts concerning the "myth." IMO both too higher and to little power can destroy a speaker pretty quickly. It all comes down to the mechanics of the speaker.

Too higher power can cause damage in several ways. One way is simply adding to much power into the voice coil and melting it down and causing the speaker to seize. To do this you need a massive amount of Overpowering to occur.I showed this to my apprentice by taking a 4inch woofer and plugging it into the wall! HAHA....240 volts at 50Hz....it was highly amusing if not extremely dangerous.  The other way happens over time.By feeding too much power, you force the cone of the speaker out to the limits of it's excursion and hold it there until the signal starts decreasing and heading into the negative, once it goes into the negative region, the cone is pulled back and held all the way back inside of the chassis until the signal starts going positive again. Remember this could be happening anywhere between 20 times a second to 20,000 times a second (subwoofers right through to tweeters included in this) now holding the cone of a speaker out for any period of time instead of it being allowed to move freely builds up resistance inthe voice coil, resistance equals heat, get it too hot and it will start to seize in sections if not altogether.

Now for the touchy subject of underpowering....don't shoot me please!!!

Someone mentioned earlier that Underpower damage occurs when the amplifier is sent into clippng "distortion" This is exactly correct!! Lets break down a clipped signal....it's a square wave, for all intent purpose, it has a flattened peak and a flattened trough. Now for the speaker to recreate those troughs and peaks it must be held in a one position for the duration of that "flatspot" Now bear in mind what I said earlier about holding a cone in one position, it builds up resistance in the voice coil, resistance = heat, and thus once again, you can cause overheating of the voice coil, causing sections to heat up and seize if not seize altogether.

Ok, I will breifly touch on distortion as I have rambled long enough....The human ear doesn't hear distortion until it is approxiamtly 5-10% of the full music signal, and that rating is for people such as us, who continually listen for distortion, the average person may not notice audible distortion until it is at 20%!!!! that means that one fifth of your audio signal is slowly damaging your speakers and in the case of underpowering, damaging your amplifier as well.

I hope this will clear up some confusion, to my fellow installers, please feel free to add, correct or criticise what I have said, these are only my opinions that I feel I have thought through well enough for them to be true.

Raymond Wilkinson-Reed