[simon94]

97 gt
I got alpine amp, boom box, the sound cuts off after setting volume past 10,and it did not do this before.
so i bought new alpine cd player, still same problem, then took out amp brought it to get tested and they said its fine

any ideas?, and i read this,what does it mean?

Problem: The sound cuts out while the music is playing.

Possible Cause
The impedance of the speakers is less than the rating for the system.

Suggested Solution
Use speakers with the correct impedance rating.

[00redgt]

speakers have to match the ohm load of the amp,for instance ur sub is 4ohm ur amp haas to be 4ohm stable,two 4 ohm subs willl have to have a amp 2 ohm stable.dvc subs aare a little differ here a site that will help you JL Audio
what is happening is ur amps is cuttin out an goin into protection mode.when u turn ur volume back down it come back on,either change ur amp,subs,or if they are dual voice coils just rewire them to a diff ohm load.whaat subs do u have?

[simon94]

thanks let me check subs and get back to u

but the system was working fine for 3 years since it was installed by car audio shop why would the amp or subs sudenly now go into protecton mode?

and dumb question what are ohms?is it something to do with measure of resistance?

[simon94]

how do i tell if i got single or dual voice coils?

[CNASHGO]

yes ohms is the electrical measure of resistance

[00redgt]

look on the back of ur sub if it has 2 seprate hook ups it dual an it should say it on the magnet or around the hook up.what subs do u have

[simon94]

i hadnt had a chance to check yet but i think i have this set up 4 svc drivers with voice coils in parallel because i have 2 subs with 2 terminals to each of them and the 2 stock rear speaker subs are hooked up as well.

so i guess i need a digital multimeter and test resitence in ohms at amp terminals and sub terminals with power on and should get reading of?
2 Ohm Subwoofers: 0.5 Ohms

3 Ohm Subwoofers: 0.75 Ohms
4 Ohm Subwoofers: 1 Ohm
8 Ohm Subwoofers: 2 Ohms
12 Ohm Subwoofers: 3 Ohms

[simon94]

they are dual but they are hooked up single and its only 1 box with 2 subs

[Bullitt2445]

Try taking your readings again, only disconnect them from the amp. sounds like your readings were also seeing the amp's internal impedance.

[simon94]

no i did not take any readings, i just copied that from the jbl site, asking if that's the readings i'm suposed to have.

I dont' know how to take the readings, so what do i do 1st disconect battery? key on or off? disconect all wires from amp ? do i take wires out from subs and measure oms at all 4 terminals?i got 4 terminals at subs with only 2 wires going to them. and then how do i measure oms at subs? and what reading shoud i expect at subs? i guess i need to pull out 1 of the subs from box to check ohm rating at the back of magnet? so far i got my old 4 channell flex 4 alpine amp all disconected out of car at shop being tested , new 2 channel alpine head unit cd player out of car with conectors disconected and 2 jbl 10's dvc subs in box in trunk.

do i use digital multimeter on the wire or at terminals of the subs and which ones do i measure all 4 or just the two where the 2 wires go?

[simon94]

I got reading, on the back of magnet of jbl sub VRC 10w0-8 and the reading i got was about 4ohms with the bride conector on and 8ohms if i take it off(i'm not sure if thats what its called but its basically a piece of metal that conects the 2 terminals)

[simon94]

I meant bridge conector

[simon94]

so acording to the jl site my speakers are discontinued
jl audio 10w0-8
DC Resistance (Re) 6.43 ohms
Nominal Impedance 8 ohms
power handling continuous 125 w

what does all this mean and what type of 4 channel amp do i need to power for 2 of these 10 subs in box and 2 front speakers, my old amp was an alpine 4 channel flex 4

[Bullitt2445]

I can recomend 3 (from the one's I sell at work and know very well) would be the JL A4300, the JL 300/4 (each at 75x4 or 75x2 and 150x1) or the Kicker zx350.4 (86x4 or 86x2 and 175x1). I like the 300/4 the best (but it is a little pricey). Based on the readings you gave (assuming you translated the meter readings correctly and I understood what you said correctly) your subs should be fine. Before investing in a new amp, though, ask the guys at the local stereo shop to check everything for you again just so you don't waist money. If they are a good enough shop with good morals ( I would hope so) then they will have no problems doublechecking your readings.

[simon94]

thanks this helps a alot, how do test my amp to see if i'm really gettin 4ohm stable? the amp is still at shop and it doesn't look like i'm gettin it back(long story) but it was older 3-4years flex 4 alpine 4chanel amp what new replacement should i look for it powered 2 front speakers and the 2 rear subs?does this look like a good replacement from ebay Alpine Model: MRP-F550 4 Channel Power Amplifier 125W RMS x 4 90W RMS x 4
but if i do get amp back one test i was told to do-- to hook up only front speakers to amp and see if it still cuts out and if does replace amp if they don't cut out just add mono amp,--does this sound right?thanks simon

[simon94]

also originaly had a 4 chanel head unit with 4 rca jacks going in when the sound starting cutting out i went and asked for the lowest price alpine cd player and later i noticed they sold me a 2 chanel, i know i could use a splitter but that would cut off some power right i geuss its better to go and get another 4 chanel headunit?

[Bullitt2445]

Originally Posted by simon94 thanks this helps a alot, how do test my amp to see if i'm really gettin 4ohm stable? the amp is still at shop and it doesn't look like i'm gettin it back(long story) but it was older 3-4years flex 4 alpine 4chanel amp what new replacement should i look for it powered 2 front speakers and the 2 rear subs?does this look like a good replacement from ebay Alpine Model: MRP-F550 4 Channel Power Amplifier 125W RMS x 4 90W RMS x 4 but if i do get amp back one test i was told to do-- to hook up only front speakers to amp and see if it still cuts out and if does replace amp if they don't cut out just add mono amp,--does this sound right?thanks simon

In a way, yes. You may also want to check your front speakers to see if they are grounded out. Take your meter leads, with the positive to the 12v battery lead and the negitive to ech of the speaker leads and see if you have 12v on each. You will need to disconnect all of the leads from the amp, and don't touch the metal of the car while testing. If you DO read 12v, then you have a speaker lead touching metal. The only remody is to remove what is touching.

[simon94]

4-channel car amplifier(specs for mrp-F550 alpine) they seem wrong? 90 watts RMS x 4 at 4 ohms (125 watts RMS x 4 at 2 ohms) 250 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)

[Bullitt2445]

Not wrong, just a bit amitious. Keep this in mind- most amps are rated using sine waves (or pure tone signals) It may do 90 x 4 at 14.4 volts at 1 kilohertz. But you will listen to music at around 13.5 volts, so those ratings may be a little high. That amp, though, still puts out 65 watts into all 4 channels, which is still very respectable for it's price. My shop sold Alpine until the first of the year, and I cannot say anything bad about it.

[simon94]

do u think this mrp-F550 alpine would be okay to power my 2 125w rms subs at 4ohms paralel and front speakers--(not sure watts) but i asked crutchfield advisor, he said if front speakers are 70w rms its ok, but if they are 90 to 100w then i should go with something stronger like MRP-F600 which has specs of
CEA-2006 Power Rating @ 4-Ohm: 100W x 4
RMS Power @ 4 ohms: 100W x 4 (1% THD)
or ooredgt told me--you need to look into a 3 channel,that powers the front 2 speakeers an it has a sub out put,kicker,rockford,an hifonics is what i would look into,not much on the alpine amps