Did i just fry my amplifier?

[YarisSedan]

So i was trying to bridge the rear channel to my speakers. Looking up online it says to take the positive of the left rear channel and connect it to the negative of the other channel. After doing this all my speakers started to clip really bad when the bass would hit. So i quickly disconected everything and put it back to the way it was. Now my rear channel has highs but no lows its like its stuck on high pass filter. But when the music is loud it sounds like the speakers are blown out like they are underpowered now.

I put in my other speakers in the rear and no change so i know its not the speaker. I checked all the amp fuses and they are seem fine.

I read that some amps are bridged internally and you can not bridge them.

My front channel seems perfectly fine just rear seems effected. Is it safe to say my deck is probally okay and all the wiring i just need to put in a new amp?

I tried looking up the specs for my amp but couldnt find any information even after emailing the manufacture. So i figured if it wouldnt work and the amp went bad i was planning on upgrading it anyways.

[Astroman]

Hm I dunno... I would say check the fuses but you already did that... I had a old amp years ago that did that, I ended up junking it. (Bought it at a pawnshop anyway).

[sqcomp]

Did you get THE smell from the amplifier? What amplifier is it? Are you sure none of your speaker wires are grounding out? ...I mean SURE!

I killed a $1000 amplifier last week because my negative wire on my mid bass was too close to a mounting bolt, being pinched. Thank the lord I bought it new and the rep advance shipped me a new one.

Just checking all your bases first.

[bzinn 1]

make sure to set the gain and crossover points back to lowest settings before bridging any thing.......the speaker may of ran well the way it was set up before but when you bridged it you most likely changed the Ohms or at least the power going to the speaker.

put is back to the way it was originally and see what you get,may of toasted the speaker,did you smell anything......you will usually know when the amp goes.....it tends to have a small stink for a few seconds.....lol

[sqcomp]

Hell with it, open that bad boy up and take a look. Beware, it may look like a nuked FET or two:



Remember, the gains on an amplifier are NOT a volume control!!!!!!! They are more of a sensitivity control. The higher you turn the gain on the amplifier, the more sensitive it is to the deck's Voltage that is coming into the amplifier. If you crank the gain up and wonder why your speakers sound like crap, you're into clipping. It's easily seen on an O-scope. Most of us don't have access to a scop so we can set our gains correctly. It took me an hour or so to meter my deck and set two amplifiers correctly.

Now, you did the right thing by turning everything off and not continuing to drive the amp. My advice is to take your system to a GOOD shop. Not any of the big box stores or chain stereo shops...most of those knuckle draggers couldn't tell their a$$ from a hole in the ground. I consisently see issues with installs from those places. There's NO friggin' way you'd get me into those places.

What we need to see (or at least know about) is the equipment you're running. Deck, amp(s), and speakers.

*disclaimer*

I apologize about the rant on big chain stores. Some of you probably have friends that work as installers in some of those places. While I will not say they're okay or not, the crap for work ethic and end result work product that comes from those places is horrible. Everyday I hear and see rat's nests and horror stories...it's too common not to be true to some degree.

[YarisSedan]

My gain is set very low. Slightly less than the front. I just ordrered a new amp. I figured my old one was underpowered anyways. Once i unplug the old one im gona unscrew the cover and look inside. Maybe its just a burnt solder joint that i can fix if not ill throw it on craigslist and see what i can get. Might have to post it as a 2 channel amp not 4 now lol.

[swidd]

How loud do you guys play while driving around? With my 300W alpine pdx 5 driving a single 10" type r, I hardly use 3/4 of full volume even when "rocking out". Any louder and it hurts!! Do you guys use ear plugs when listening to music??

[sqcomp]

Swidd...that has a lot to do with the output Voltage of your deck juat as much as the amplifier. For example, I have three amps in my signal chain. I contsistantly listen to it at around 80% and up. Why? The voltage from the deck doesn't kick up to dynamic levels until that point. That being said, I've adjusted the amp gians so that NOTHING ever clips no matter what volume I have it.

So...what amp are you replacing it with?

[YarisSedan]

Alpine MRP-F300
V-Power Series 4-channel car amplifier

[bzinn 1]

Hey has anyone done a thread on how to properly tune an amp with DMM.....it is so easy to do you will be amazed you've never done it before.......

Honestly it is one of the best things I ever learned to do for a system.

[YarisSedan]

Originally Posted by bzinn 1

Hey has anyone done a thread on how to properly tune an amp with DMM.....it is so easy to do you will be amazed you've never done it before.......

Honestly it is one of the best things I ever learned to do for a system.

I dont think so but i do own a DMM maybe you could post a DIY on how to do this.

Mine is currently set up the old fasion way. Turning volume up to 3/4 way and then adjusting gain till it clips.

[sqcomp]

Yeah...when audible clipping occurs, you're already well into the bad $hit. What DMM do you have? Also, I didn't use a DMM to read the waves...still, I'm sure that there are DMMs out there that have the capability.

[YarisSedan]

Originally Posted by sqcomp

Yeah...when audible clipping occurs, you're already well into the bad $hit. What DMM do you have? Also, I didn't use a DMM to read the waves...still, I'm sure that there are DMMs out there that have the capability.

Its a craftsman one with autoranging. I used to have a a real fluke meter but its somehow gone missing since i left my last shop.

[talnlnky]

Originally Posted by sqcomp

Yeah...when audible clipping occurs, you're already well into the bad $hit. What DMM do you have? Also, I didn't use a DMM to read the waves...still, I'm sure that there are DMMs out there that have the capability.

you don't have to read the waves like a scope. How you set it with a DMM is by reading the voltage.

Here we go...

Clipping is an increase of power going to the speaker without an increase of cone movement/sound production. Power = voltage * amperage, and each amplifier is limited to how much voltage they can produce. I want to say that a 1200w amp will be somewhere in the range of lime 70v... But I could be WAY off on that... Been a long time since I was into that stuff, doesn't matter really anyways...

So... if an amplifier reaches is max voltage, but you continue to turn up eq/bass boost/gain or volume on the deck you will in turn just get more amperage going to your speaker, but the voltage will still be the same.

So... what you need is...
1) a speaker/sub (it'll be crazy loud unless the speaker is playing free air).
2) DMM
3) A cd with sine waves/test tones that don't change pitch/frequency.(have sine waves that the speaker would play, i.e. if its a sub, 50hz is good, if it is your midrange speakers, 500hz.
4) some ear plugs or gunmuffs, it might get loud.

Now:
Deck clipping:
1)Turn gain down all the way.
2)have deck volume down all the way, put your cd in, set it for repeat-continues play.
3) Grab friend to control deck
4) hook up DMM to speaker wires or speaker terminals on amp (SUB HAS TO BE HOOKED UP)
5)slowly turn the volume up on the deck and watch the A/C voltage rise. keep increasing the deck volume until you notice the A/C voltage isn't increasing anymore. Once you find that point remember what volume setting you're at on the deck. Most decks start to clip around 80% of full volume when playing cd's. So... don't be surprised if it stops increasing somewhat early.

Amp clipping:
6) now set your deck for 1 or 2 clicks below where you saw it start to clip with the dmm.
7) use the gain knob to slowly increase volume just like you did before with the deck. Remember to have the sub hooked up, and watch for the voltage to peak.
8) once you find where the voltage no longer goes up any higher, dial back just a tiny bit.

Now you know approx. where both your deck & amp clip, If you then dial in any eq/bass boost or even crossovers you change how early or late the audio signal will start to clip.

Like I said before, this can be a loud process, so try not to be a douche and find a vacant field to do this at because it might take a few minutes and pure sine waves can travel very long distances.

[bzinn 1]

that says most all of it......there is also a formula watts x ohms then take the square root of it.......

So say my sub is 1000w and I want to run it with clean power I take the 1000 and multiply it by the ohms I want to run it at.....lets say 2.......so now I have 2000.....take the square root of 2000 and you get 44.721.....that number is basically the number in this case you want to be reading on the DMM.

The 44.721 is AC voltage,so you with tone disk in,I use a 50hz tone disk for my setup....play the disk and turn up the gain till you read 44ac volts.....now you are supplying 1000w to the sub.

Of course these numbers are differant every setup,follow the instructions on how to set the deck eq flat,loudness off,play tone disk and turn up volume to around 80% of full on deck......

By doing this it is much harder to blow up amps and subs........

Now to set crossover points.......this part is easy.....

Say I want to run my sub up to 50 hz before crossing the signal over to the comps....

PLay 50hz tone disk,I usually put deck volume on about 40% for this,I am deaf and it is easier to hear the change point when it is a bit louder.

Turn up the crossover knob,from 0 to where you hear the volume start to get louder,when you hit the crossover point you will hear it start to fade off in volume....that gets you in the ballpark within a few hz of your crossover point.

Now I like to set crossover points first,my reason is that way the sub is only getting power at the ranges I want it to play at.....helps get rid of some of the clipping in frequencys I dont want the sub to play.

Now to tune comps it is about the same thing,except use a differant tone disk,I use 400hz to tune them and follow the same process

Think me and the guys will have to get together and write up a how to and post up pictures,I am gonna install my amp and such in a few weeks,I could take some pictures of step by step so to speak......

It really is super easy to do this and from what I have seen by those that do it their music is clean,clear,and loud....their equipment such as amps really dont get hot,fuses dont blow,and subs dont go whap and buzz...

[bzinn 1]

Also these steps are also a bit limited to the quality of equipment,for instance not all decks clip at 80%,have seen some that can go to like 95% of the volume before they clip.

Seen subs clip at differant levels as well,mostly seen subs under powered and over powered.....I try to run them in the RMS the manufacture recomends......so say you have a 1000w sub and the RMS is 600,I try them powered at 600w and see how they sound and then try a bit more power,you can push it a bit but will hear when it starts to clip.

[sqcomp]

...and some can go full tilt without clipping...I'm smiling nice and wide on that one.

The issue I have with not looking at a wave is that you can actually see the plateau start to happen on the scope BEFORE the Voltage peaks. I'll have to double check the Taln method while looking at a scope. I'll report any variances, oddities, or whatever might come up that is notable.

I'll do this when I dial in the last 2.9.

[JumpmanYaris]

Yaris Sedan did u fry ur amp or still dont know?