terrible sounds speakers

lately my stereo sounds terrible. I have screwed with settings.
My stereo consists of

jvc double din

Rockford fosgate speakers all around
jl audio stealth sub box with kenwood shallow mount sub
1000 watt amp

it sounds good quite but when i turn it up loud the speakers get very distorted and crackly. They sound great when they are low but as soon as its cranked even remotely it sounds shitty.

Is it time for new speakers?

 

are you speakers rated for the correct power output? Whats the RMS output of your amp and the RMS of your speakers?

 

rockford fosgate fanaticx 4 ohm speaker rms 8.70
http://www.crutchfield.com/S-a27gSScMAm4/p_575FNX2614/Rockford-Fosgate-FNX2614.html#details-tab
deck
http://mobile.jvc.com/product.jsp?modelId=MODL029180&pathId=133&page=3

 

the amp is not hooked to my speakers. speakers hooked to deck. amp is for sub only.

 

would these work for me?
http://www.visions.ca/Catalogue/Category/Details.aspx?categoryId=338&productId=9509&sku=ES60

 

built in amp

• Maximum Power Output
• 50W x 4

• Continuous Power Output (RMS)
• 20W RMS x 4CH at 4 ohms and no more than 1% THD+N

• MOS-FET Amplifier
• Yes

• Audio DAC
• 192kHz/24bit

• Equalizer

• 3-Band Parametric iEQ
• Yes

• Easy EQ Setting
• Yes

• High-Pass Filter/Low-Pass Filter
• Yes/Yes

• AV Input Terminals (Video + L/R)
• Yes

• Front AUX Input
• Yes

• Video Input (Camera)
• Yes

• Line Output Terminals (pair)
• 3 Pairs (Front + Rear + Subwoofer)

• Subwoofer Output with Level/Frequency Control
• Yes

• Composite Video Output
• Yes

• Frequency Response
• 40 - 20,000Hz

• Load Impedance
• 4 ohms (4 - 8 ohms allowable)

• Pre-output Level/Impedance
• 4.0V/20k ohms

• Pre-output level/impedance
• 4.0V

• Video Output Level/Impedance
• 1.0Vp-p/75 ohms

• Video Input Level/Impedance
• 1.0Vp-p/75 ohms

• Audio Input Level/Impedance
• 1.5V/20k ohms

 

I would invest in a

$290 Alpine KTP-445u Universal Power Pack

Alpine KTP-445u at 45x4 per channel or a mids/high 4 channel amp for the speakers.

 

Its time for an amp. what is happening you are reaching the peak of the radio "chip" not amp. Find a good amp rated for the speakers RMS handeling and tune accordingly with crossovers and set the gain properly.

 

What settings have you "screwed" with? I assume it's bass and treble settings, or the internal EQ, either way, yes, you can make your speakers sound like crap. If you were happy with the sound before, then try to find the settings you messed with, and reset them to what they were before, or read the manual, and see if there's a reset button on the deck. As mentioned, you may want to consider an amp as well, as the power from an amp is much cleaner than any deck. You have to consider the space and cost options though, as it's a bit of an investment to get an amp set up properly, wiring, fusing, RCA's, etc. Then you need to consider the power draw of an extra amp on your battery and alternator. As mentioned the

$290 Alpine KTP-445U Universal Power Pack

Alpine KTP-445U power pack may be the way to go. Only draws 15 Amps, can be hidden behind the deck, and what I would do is run it in 2-channel mode, and run the rear speakers off the deck with the sound faded forward, so as to get better imaging.

 

Its simple, your feeding your 70W speakers only 20W and then clipping the signal because they are not getting enough power.

You need an amp rated at 4 x 70W or more @ 4 ohms for the four door speakers.
Also you need to tune your system.
Use a Digital Multi Meter, watts of the driver x the Ohms and then find its square root. So for your 70W speakers x 4 ohms = 280 and its square root is 16.73.
So to tune the amp youll set your head unit to 75% of its maximum volume setting, make sure the EQ is set to flat, and turn your amps gain all the way down. Then set your DMM to Voltage and read the positive and negative terminals as you start to turn up the gain, continue turning it up until you reach your reading of 16.73 or 16 if your DMM isnt that specific.
You now know that your speakers are getting the 70W of power they need, then use a tone test CD to verify that your speakers are not clipping at any volume setting (on the head unit) and DO NOT go over the 75% of volume setting you used while tuning.
This ensures your head units amp is not being stressed, that your speakers are getting proper power, and you are not clipping at any Hz range.
High crossover for sub should be about 80-100hz and low for speakers should start just above the same range