can a head unit at full volume blow db401's and db651's?

ahardy17

serious question. i believe it's a pioneer premier head unit in an accord and it blew the factory speakers. my friend is reluctant to buy these speakers only to have his sister blow them out while he's away at college. he's too cheap to spring for an amp by the way so they'll be running off the head unit's power.

zarrdoss

probably did not blow from to much power but from distortion, same thing will happen with above mentioned speakers connected to head unit played over the clean power limits of the head unit. Get a amp and a sub and wait till he comes back form college.

MacLeod

Distortion doesnt hurt speakers - overpowering them is the only thing that does.

Id generally say no. Even at full clip I doubt a head unit could muster up much more than 30 watts per channel which shouldnt be enough to blow these.

But I guess if you were listening to very bass heavy music like rap, and at full volume it might be enough to pull the suspension loose.

ahardy17

hmmm well the sister happens to be my girlfriend and i know she does listen to some rap and likes her music loud....i might try to get the brother to spring for a cheap 4 channel amp. he's very budget-oriented. if i did that the set-up would be comprised of my db651's and some cheap kenwood 6x9's because i'm using my db690's if i get him to buy a sony 4 channel amp pushing 60 watts per channel could any damage be done to either pair? considering the kenwoods can handle 80 rms?

Toxis

distortion doesn't hurt speakers? That's a first. I've overpowered a hundred speakers and never had one go bad. Different methodology I guess.

I say the radio at full volume will blow the speakers and will blow pretty much any speaker. The better the speaker, the more abuse it'll handle but still can and will blow. It'll just take longer to do so.

ahardy17

i'm with toxis come to think of it i've read a million times that dirty power and distortion is worse for a speaker than too much power. i mean i know too much power blows them too i've blown 2 pairs with my receiver...but the 4 channel amp should provide enough volume to satisfy without blowing them right? as an upgrade from factory?

MacLeod

A speaker doesnt care how clean or dirty the signal its getting is. As long as its within its thermal limits itll be fine.

The ONLY 2 ways to kill a speaker (not counting physical damage or manufacturing defect) is to overpower it. You either build up more power in the voice coil than it can dissipate or you force it beyond the limits of the suspension. The only ways to do this is by overpowering. Hook up a head unit channel to a typical 8" sub and then turn the volume to full tilt max. I guarantee you that little 8 will play all day long. Why? Because that measly 35 watts coming from the head unit is neither enough to build up excess heat in the voice coil or overdrive the suspension even tho its almost pure, clipped distortion.

There are 2 reasons people associate distortion with fried speakers. First off, when youre overdriving your speakers to their suspensions limits, theyll start distorting. This isnt necessarily the signal distorting but the speaker itself. Also, most speakers are fried when an amp is driven into clipping. When this happens the amp sends out a signal at a wattage limited only by its input voltage. The signal is pure distortion but its also 2-3 times the normal rated power of the amp and if youve got a 50 watt amp hooked up to a 50 watt speaker....well you do the math.

So the distortion in both these cases isnt the cause, its just a symptom. Kinda like if I shoot you with a gun, its that pesky bullet thatll cause all the problems. That loud BANG is just coincidental.

ahardy17

soooo wait if the head unit's amp is really being pushed (full volume) even if it's only rated at about 17 watts rms it could blow say, a pair of db651's if it starts clipping? i need these speakers to NOT be blowable essentially

ebumdude

MacLeod wrote: »

A speaker doesnt care how clean or dirty the signal its getting is. As long as its within its thermal limits itll be fine.

The ONLY 2 ways to kill a speaker (not counting physical damage or manufacturing defect) is to overpower it. You either build up more power in the voice coil than it can dissipate or you force it beyond the limits of the suspension. The only ways to do this is by overpowering. Hook up a head unit channel to a typical 8" sub and then turn the volume to full tilt max. I guarantee you that little 8 will play all day long. Why? Because that measly 35 watts coming from the head unit is neither enough to build up excess heat in the voice coil or overdrive the suspension even tho its almost pure, clipped distortion.

There are 2 reasons people associate distortion with fried speakers. First off, when youre overdriving your speakers to their suspensions limits, theyll start distorting. This isnt necessarily the signal distorting but the speaker itself. Also, most speakers are fried when an amp is driven into clipping. When this happens the amp sends out a signal at a wattage limited only by its input voltage. The signal is pure distortion but its also 2-3 times the normal rated power of the amp and if youve got a 50 watt amp hooked up to a 50 watt speaker....well you do the math.

So the distortion in both these cases isnt the cause, its just a symptom. Kinda like if I shoot you with a gun, its that pesky bullet thatll cause all the problems. That loud BANG is just coincidental.

This is exactly what happened to my two sets of db6501's that i have gone through. Both took about 5 months each to blow. Since, just upgraded to mm6's. The sound is a lot better.

MacLeod

ahardy17 wrote: »

soooo wait if the head unit's amp is really being pushed (full volume) even if it's only rated at about 17 watts rms it could blow say, a pair of db651's if it starts clipping? i need these speakers to NOT be blowable essentially

I suppose its possible. I doubt it could build up enough power to fry the voice coil but it could generate enough temporary bursts to eventually wear out the suspension. Even at full clip tho Id be surprised if a head unit could muster up much more than 50 watts. That might be enoug to take out the 4's but I would think the 6's would take more. But if theyre blown then it mustve been enough.

And there is no such thing as not blowable. If you dont want to blow your speakers by an appropriately powered amp, set the gains properly and use common sense with the volume knob and your speakers will last.

ahardy17

MacLeod wrote: »

And there is no such thing as not blowable. If you dont want to blow your speakers by an appropriately powered amp, set the gains properly and use common sense with the volume knob and your speakers will last.

well considering the sister won't be tampering with anything other than the volume knob, i think it should be safe to set the gain appropriately on a 4-channel amp running the db651's and a set of 6x9's. i mean if the gain is way down she'll be able to crank it full volume and not know the speakers can do any better...at least that's the plan

danger boy

the distortion must have been unreal off that head unit.

Kinetic

yes accordingly to the white paper of the SRs

arun1963

A speaker doesnt care how clean or dirty the signal its getting is. As long as its within its thermal limits itll be fine.

The ONLY 2 ways to kill a speaker (not counting physical damage or manufacturing defect) is to overpower it. You either build up more power in the voice coil than it can dissipate or you force it beyond the limits of the suspension. The only ways to do this is by overpowering. Hook up a head unit channel to a typical 8" sub and then turn the volume to full tilt max. I guarantee you that little 8 will play all day long. Why? Because that measly 35 watts coming from the head unit is neither enough to build up excess heat in the voice coil or overdrive the suspension even tho its almost pure, clipped distortion.

There are 2 reasons people associate distortion with fried speakers. First off, when youre overdriving your speakers to their suspensions limits, theyll start distorting. This isnt necessarily the signal distorting but the speaker itself. Also, most speakers are fried when an amp is driven into clipping. When this happens the amp sends out a signal at a wattage limited only by its input voltage. The signal is pure distortion but its also 2-3 times the normal rated power of the amp and if youve got a 50 watt amp hooked up to a 50 watt speaker....well you do the math.

So the distortion in both these cases isnt the cause, its just a symptom. Kinda like if I shoot you with a gun, its that pesky bullet thatll cause all the problems. That loud BANG is just coincidental.

While overpowering is the 'root cause' of blown speakers, distortion allows you to 'hear' that you are overpowering. Hence I had mentioned on ebumdude's post that sustained distortion will kill speakers. Folks who may not be well versed with gain setting, may (and do) use the gain knob as a 'volume knob' and hearing distortion is thus a ref point for them. I should have explained this better.

Mac is right that the sequence is overpowering-->distortion-->blown speakers. Hence overpowering is the root cause.

On gain setting, my understanding is as follows:

You should set the gains on your amp based on the rms volts of your hu's output signal. Hence for my pioneer p80prs HU which gives a 5v rms signal, I have the amp gain on my pa500.4 set at about 4.5 which is about 12 o'clock on the gain dial. (the gain sensitivity on the amp runs from 250mv = 5 o'clock to 7.5 volts = 7 o'clock).

The idea behind matching the hu signals and amps voltage, is that when you turn the volume of the hu to 80%, (to get the loudest 'clean' signal), the amp is also hitting its max clean output at the given voltage.

I hope the above is correct.......

arun1963

Just one correction on the gain setting mentioned above:

I am running momo comps upfront bi-amped of the 500.4 The gain on the rears (mids) is at 11'oclock and the gain on front ch (tweets) is just a touch under 11.

cadenceclipse

yeah we know
u match input voltage when maxing out HU volume. i always kept amp gains alll the way down to 8-9v. HU 8v preout. makes sense right? i also always maxed out volume(almost) 79 out of 80. just recently changed to 55 out of 80 and turned up gains bout half way. so yeah, 80% works pretty well

arun1963

wow did it play clean at 79/80? Didn't you have distortion at that level? how much does your 4ch put out?. Yeah the 80% rule works well. I can hear didtortion past 52/64. Normally play it at 50. This is with the amp gain at about 3.5v. I ran it at 4.5v and it sounded great at about 45-48. Above 50 there was just a hint of distortion, if i heard the mids alone w/o the sub. Turned the gain down as I was afraid of hurting the speakers.

cadenceclipse

yes very evry clean, no distortion. i hate distortion drives me bonkers(mmm, bonkers brings back happy memorys). 4 channel class A 75 x 4. to b honest i assumed it was cause of high preouts (8v). still got em(8v) but diff. HU from cd8053 w/ balanced output(16v, 8vrms?) to 7200mk(8v, supposedly rms). couldn't get same ish at full volume so just recently dropped to 55(must say after trying b4 but 2 no avail) and wammo!

MacLeod

The problem with setting your gains at zero is you could be missing out on some power. If your gains are at zero then, depending on your amp and head unit, your amp could only be at 50% when the volume is at 95%. This means youre missing out on some good clean power that can add dynamics to your music.

I prefer to set gains by ear. The tried and true method of setting the volume at 75-80% and turnning the gain up til it starts to distort, then back it down a tad and youre off.

This method gives you all the clean power your amp will put out AND keep the amp from making more power than your speakers can handle.

cadenceclipse

thanx mac. only issue is "down a tad" which seems like the common answer or phrase only just a bit too vague for me. guess the average joe listener can back up a tad (or not:o) and be happy or not even notice the difference. i know i have a sensitive ear but i also know the smallest tad seems to make quite a difference. as i was saying(or maybe meant to but my computer keeps freezing when i hit "submit reply". extemely annoying, but i keep trying:D) can't wait till amps have digital filters(actually mine does) but where u can set filter digitally to any freq. u know like HU but ANY freq. turning the nob seems rather old school ya know? how bout your processor mac. imagine thats not digital eh?

ahardy17

cadenceclipse wrote: »

yeah we know
u match input voltage when maxing out HU volume. i always kept amp gains alll the way down to 8-9v. HU 8v preout. makes sense right? i also always maxed out volume(almost) 79 out of 80. just recently changed to 55 out of 80 and turned up gains bout half way. so yeah, 80% works pretty well

8V preout? that's....impressive..i think. majority of them seem to be in the 4.5-5V range

cadenceclipse

eclipse budy . 5v is for wimps haha i kid