Hey everyone. I found 2 headunits that I really like but do not know if they are worth the money.

The only difference between the P80MP and the P8Mp is that the P8MP has a 6.5V Pre amp..... versus the 4V on the P80MP...


Other than that they seem to be exactly the same.

P80MP = 270 shipped
P8MP = 315 shipped


What does the pre-amp voltage do? For now I will not be running an amp, possibly in the future but who knows.



Both are 27RMS....60W output... I think Pioneer discontinued the 80 and made the 8 the new model.


Any help would be great. Cuase for 45 bucks I can get the wires, din converter, and all the things necessary to install it correctly.

 

If you're not planning on running amps, it wont make any difference.

If you do run amps, the higher pre-amp voltage will allow you to run your amps with a lower gain with the same power.

Essentially the lower your gains are, the lower the chances are that you will amplify other noise or intereference in your stereo. That's all there really is to it. I have used non premier decks in the past, and have had great results.

It's really up to you, but if running amps and if you can swing it, get the premier.

ravi

 

ditto,

honestly, you shouldnt hear much of a difference, 4 volt is pretty high and with a well installed system, there shouldnt be much noise, 6.5 is better but you have to decide if you need it, if you get the p8mp, and want to maximize your potentila, make sure you get an amp that can accept a 6.5 volt input or more

b

 

quick question for you audiophiles, i have a Kenwood 8017 with 5V preouts going to a JL 500/1...where should i have my Input Sensitivity set at? or do i really need to get a voltmeter and a Sine wave CD to set that?

 

You can use the tutorial at JL to do it
http://mobile.jlaudio.com/products_a...php?page_id=30

Test Tones Link

However I would suggest instead of setting your HU to 75%, set it to the maximum level you would generally listen to the HU. The reason for this is because each HU will have different clipping levels.

Use the formula to set the voltage instead of the chart that JL provides:
Sqrt(Power*Resistance) = Voltage

So it's
Sqrt ( RMS of sub * Ohms you will be using) = Voltage you will need to set for gains

Now thats the proper way to set the gains on the amp.

Now if you usually use the eq like bass +2 and treble +1 in your HU you might want to leave it at that when setting the gain instead of setting it flat. The reason being that if you set the gain to the correct volts then turn up the bass you could cause clipping.

An oscope can also be used to best determine when there is clipping, but isn't really required.

 

so what would you guys get? I mean its a pretty big difference. I will get an amp later on...but not right now (prob in the summer....hopefully)


I have aftermarket speakers.... so i was hoping a nice headunit will be good enough

 

hey thanks for that website, it'll help me out greatly...so since i'm using 2 10w6v2 subs on a 500/1 amp i'll be aiming for 20V or 28.3V? each sub is 400w RMS and wired in parallel...on JL's website it says impedence then becomes 1Ohm...so sqrt(400*1)= 20 or do i take both subs into account, ie. sqrt(800*1)= 28.28V?

 

4v preamp is still pretty high IMO.... im not gonna go for a amazing setup....


Debating weather or not to spend the extra 45-50 bucks

 

Kabs: I would just stick with the 4V preout. You most likely won't notice a difference in 6.5V preout vs 4V preout. Its usually just to avoid interference from noise. If you wire your car correctly for the amp and use the right wires then there shouldn't be any problem with a 4V preout. If you do get noise often times its the RCA's, and I found twisted pair Cat5e cables to work to get rid of my noise in my old car. Some say it restricted certain highs, but it was like 20khz+ so I didn't notice a difference between those and my other so called "high quality" rcas. The twisted wires in the cat5 seem to protect against interference, while the shielding on most car audio rcas are some sort of foil that seemed to actually pick up noise. Odd thing was the car audio rca's worked better in my dad's home theater room

Rasengan:Sorry I mixed some stuff up. There's two things to the formula. JL has the right voltage for their amps in the manual. So basically if you want max clean power from your amp you would take the formula and put:

Sqrt ( RMS of amp * Ohms you will be using) = Voltage you will need to set for gains

When the amp has a higher rms than the sub(s), you would then go with:
Sqrt ( total RMS of sub(s) * Ohms you will be using) = Voltage you will need to set for gains

This is to either provide max clean output from the amp without clipping, or to make sure the subs are not overpowered.

I just read up on the JBL 500/1 manual and it states it will go into safe mode and lower the power if put into 1ohm(most amps can't do 1ohm reliably). Another thing that JBL has put into the 500/1 monoblock amp is a thing they call RIPS which basically means the amp outputs 500watts from 1.5ohms to 4ohms. Unlike most amps where if you drop the ohms in half you should technically be able to gain double the power, but because of the increased strain the amp is usually rated at a lower rms than double. So your best bet is to wire it in series at 4ohms as no matter what ohms you pick you'll still get 500watts.

In this case the voltage you'd need would be 44.7 which is in the manual. The subs might be a bit underpowered, and the JBL might be underrated, but you'd need an oscope to know exactly where the JBL is clipping, and to know if you can go higher on the voltage. If the subs do seem underpowered, try lowering the highs/mids to match the sub instead of bumping the gain higher, or you could raise the gain higher but sounds like the JBL is going to try and keep it right at 500watts.

 

thanks man


What is everything that I need for the install???


Just the din converter, and wires right? I know circuit city sells the wires that plug into your stock ones and then plug into your HU... so thats not that hard to install


Im trying to figure out what is so hard about installing...

 

Well if circuit city has a wiring harness, then the hardest part of the install I'd say is removing the dash.

I haven't changed out my HU (maybe in the future) for this car, so I can't really comment on if there is an adapter or not. If there isn't then you'll need to read the faq for the wiring chart and match up the wires with the new HU, which just requires a bit of a soldering.

Other than the wiring, installing headunits are pretty basic.

 

yea i took apart my dash before so thats not a prob... then its settled im ordering my headunit friday =)