Rockford Fosgate 800.2 Problems...

 

New member
Username: Djflipnautikz

Miami, Fl United States

Post Number: 1
Registered: Sep-04
Aight guys i am new to this forum which i came acroos and i need a lil suggestion from some people that know thier stuff... i have a nice little set-up for 2 12" subs with an older model of a Rockford Fosgate 800.2 amp. its 800 watts and has 2 channels. i have blown already FOUR 12" subs. i had 2 pioneers 600 watts max blow in 20 min, then i had 2 kicker comp's parelle wired dropping it from 4 ohms each to 2 ohms and then bridged the amp and blew those in about an hour. then i just finished buying 2 audiobahn aw1251t dual voice coil 400 watt rms brand knew and after baout 3 - 4 days i blew those. can anyone tell me whats wrong? too much power amp is messed up? thanks in advanced
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 214
Registered: Sep-04
Sound like too much amp for not enough speaker(audiobahns don't count).

Is that amp stable bridged into 2 ohms(1 ohm stereo)?

-Fishy
 

New member
Username: Voodooi

Post Number: 5
Registered: Sep-04
You have the same problem as me. I blew out my 1 10" RF in 10 days then another in 15 min. Then i switch to 2 10" PG Octain , blew those in 10 days, now i have 2 12"PG xeon 12D4, but now my amp 80v melts and now i have it on 70v, but it can last me only 2 hour before it is too hot(amp). I have MB quartz AMPS RAA2400.
 

Silver Member
Username: Fishy

Tamarac, FL USA

Post Number: 217
Registered: Sep-04
Are you guys melting the voice coils or physically destroying the surrounds or somethin?

I have a feeling you all may be running running your amps at too low of an impedance.

-Fishy
 

Silver Member
Username: Pat_l

Tucson, AZ USA

Post Number: 597
Registered: Apr-04
YOU DONT NEED BIGGER SUBS. You have your gain set a max, or all the way up. This is causeing the voice coils to get really hot, which in turn blows subs. If you have blown 4 subs already then it is your gain. Turn that down. It only needs to be around 3/4 max and under that.
 

New member
Username: Djflipnautikz

Miami, Fl United States

Post Number: 2
Registered: Sep-04
ok my 2 audiobahns are dual 4 ohms voice coils. and the amp is 400 wats x 2 @ 2 ohms. the guy wired them connecting the positive and the negative on one voice coil to the other one and from the other voice coil 2 one channel.so i am guessing he dropped the ohms from 4 to 2 in which it is stable. the amp was not bridged when i blew the audio bahns. i have blown a total of 6 speakers and it sux. =(
 

Bronze Member
Username: Saosin

Post Number: 28
Registered: Sep-04
hmmm, maybe your amp is clipping? to know if it is i need to know the voltage of your pre-outs and the gain setting to your amp
 

Silver Member
Username: Pat_l

Tucson, AZ USA

Post Number: 602
Registered: Apr-04
CHECK YOUR GAIN
 

Bronze Member
Username: Decde

Canada

Post Number: 48
Registered: Sep-04
CHANGE YOUR FACKING AMP
The problem is FOR SURE the amp. Thrash the damn thing and buy a new one. I don't know how u keep it after blowing 6 sub (for a total of a grand in a half btw) when a new amp is like 3 brownies. My opinion is change your amp, you'll be better off
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1879
Registered: May-04
If you're listening near full volume it would explain it anyway. Subwoofers need to be broken in, and especially if you have your gain set too high, you'll destroy them very, very quickly. You HAVE to break subs in for at least 20 hours, I usually break in for 40-60, of course I never go full blast anyway. When subs are first being used, you have to loosen up the suspension, the surround, the voice coils still have glue on them that has to burn off (this glue also cuts a little of the heat dissipation) etc. The fact that you blew a subwoofer in 15 minutes tells me you're not a casual user, you need to be conservative with the volume knob. Set the gain correctly if it hasn't been done, then break the subs in for a couple of weeks (yes, weeks). After that, you can crank the volume up higher. If the subs still blow, then get your amp replaced. You probably need better subs as well, those all have tendencies to blow fairly easily.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1880
Registered: May-04
Also, what kind of enclosure were you using?
 

New member
Username: Ericaraudionut

Post Number: 4
Registered: Sep-04
I sell/install car audio at a major corporation (think yellow tag). We sell rockford and unless its team rf or power, i wouldn't touch it. and even at that it's overpriced considering the quality you get. Try something else we have tons come back defective. just aint quality stuff. it could be the ohm load you're operating at or the gain...if the amp wasn't a rockford i would say oherwise, but NEXT AMP.
 

New member
Username: Djflipnautikz

Miami, Fl United States

Post Number: 3
Registered: Sep-04
well truthfully i do not have enough money just to buy a neew amp like dat. i wish i could but it isnt that easy. i have not checked the gain yet but it is the first thing i am going 2 check when i get the new subs. i get new subs today because i have warranty on them. and i did not know you have to break in the subs, i aint a proffessional so thanks for the tip. these subs i am going 2 break in and adjust the gain. where should i set the gain and how should i wire up these speakers? they are dueal voice coil and i have a feeling i could wire them up better then what these people are doing. if you guys have any suggestions on how 2 wire up these 2 aw1251t audiobahns...dual voice coil and where should i set the gain at??..well thanks in adnvaced...
 

Bronze Member
Username: Ericaraudionut

Post Number: 12
Registered: Sep-04
sorry man didn't mean it about the amp, you could have done alot worse. trust me... the first subs i ever bought were made by a company called kracko. talk about young and dumb i cut the cake at one time. anyway, you're gonna want to keep you're gain at about halfway for the first couple of days. then keep it at a hair below 3/4 of the way up. that will give your subs a healthy workout. Here's whats up with your wiring. when you had your comps, you had the subs wired right at the box end but when you bridge your amp you cut your ohmload in half again making that a 1ohm load , that amp doesn't like that. wire youre new subs parallel but this time run each sub to it's own channel. do not bridge it. you should get great sound operating at 2ohms like this, assuming you have a good enclosure.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1897
Registered: May-04
The gain setting is totally dependant on your head unit. Turn the head unit up to about 3/4 volume, then turn the gain up until you hear distortion, and then turn it down until it just stops. After this, just don't turn the volume past 3/4. Of course, the most accurate method is with an oscilloscope, but most people don't have one lying around. Personally, I'd wire the voice coils in series, wire the subs in parallel and bridge the amp that way the subs can be mono.
 

Bronze Member
Username: Ericaraudionut

Post Number: 14
Registered: Sep-04
bridging amps kills damping factor, which kills s.q.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1904
Registered: May-04
Damping factor has to be taken with a grain of salt anyway. Running a 2 ohm load will degrade it as well. A stereo signal running to 2 subs will kill the imaging. SQ doesn't primarily come from damping.
 

Gold Member
Username: Jonathan_f

GA USA

Post Number: 1905
Registered: May-04
Damping from a 4 ohm bridged load is exactly the same as a stereo 2 ohm load. Remember damping is measured by the speakers impedance divided by the amps internal impedance. An amp bridged to 4 ohms will perform exactly the same as an amp running a 2 ohm stereo load. An amp with a damping factor of 1000 at 4 ohms will have an internal resistance of .004. At a bridged load, this doubles to .008, this is because when you bridge you're adding the two channels, and the impedance combines in series, doubling the impedance of the amp. 4/.008 results in a 500 damping factor. If you run a 2 ohm load, 2/.004 is 500 as well. Same results for bridged and 2 ohm, just the bridged load will be in mono. What I meant by taking it w/ a grain of salt is this: Most manufacturers don't even specify damping, and most who do specify it measure in a situation that is a single tone(1 khz is typical) and with a specific resistive load. There really is no accurate way to assure you a specific damping factor because the load they used will differ from your application(the speaker you're using). When you that amp on a sub that's 100hz and below, results will dramatically differ. Damping is totally dependant on the load presented and the frequency it's done at, because both the amp and speakers change impedance with frequency. If looking for an amp, look at those that are rated ats >(whatever factor is) from 20hz-20khz. It assures you this much with a certain impedance load.
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