what speakers to buy. keep blowing them.

[DAKSTER]

I think we are on topic, its not power thats blowing his speakers up..

 

[Beauzza]

Get hertz 250xl

 

[sweefu]

So my assumption from that is that your Alpine unit doesnt allow you to turn it up beyond a certain level, that which starts creating too much distortion.

Most factory units dont have that feature (neither of my Kias for a start, and one of them has less than 1000km on the clock so it should be a modern enough HU lol), and the volume knob/switches will push max power and distort horribly if you crank them up. I assume a lot of aftermarket HU's also behave the same.

You've used your system as a benchpoint, and possibly your head unit is helping out here. On the Pioneer system in the Berlina, the distortion comes in at around 40 on a scale of 50. give or take a few depending on whats being played. This applies from the HU outputs, or from amps via RCA, makes no difference.

Am I correct in thinking the HU preamp is what supplies the signal to the RCA outs in the first place?

No, this your thinking is incorrect. It has nothing to do with the brand of headunit I am using, it was the same situation with my previous Sony unit and the JVC unit before that, its about appropriately setting your gains and tuning the system as a whole. You could have crappy speakers and a crappy amp and crappy headunit, tune it properly have no audible distortion, though it probably won't be overly loud. Please note the difference between audible/harmful distortion and THD in general, there will always be some THD, but its a matter of keeping it low.

 

[one_and_only2004]

Dynaudio splits - they're delicious.

 

[vrollin]

No, this your thinking is incorrect. It has nothing to do with the brand of headunit I am using, it was the same situation with my previous Sony unit and the JVC unit before that, its about appropriately setting your gains and tuning the system as a whole. You could have crappy speakers and a crappy amp and crappy headunit, tune it properly have no audible distortion, though it probably won't be overly loud. Please note the difference between audible/harmful distortion and THD in general, there will always be some THD, but its a matter of keeping it low.

Simply running your amps at minimum gain and cranking your head unit to max is not tuning the system... And yes there will be clipping at max on the head units...

 

[Nic92]

why dont you just refer to the amp manual. and for subsonic and low pass, should be very easy (just ask an expert)

on my manual it says:

Level (GAIN) Control Setup:
Ensure that the Level is turned completely to the left prior to turning the system on. Next you should insert a CD or cassette that you are familiar with
to use as a reference, and turn the head unit volume control to about 80% of its full setting. The system sound level will of course be very low, and
the following procedures will help you to match the amplifier input sensitivities properly to the head unit output signal level.
It is important to match the amplifier LEVEL input sensitivity to the Radio/CD output sensitivity. This can be located in the Radio/CD manual.
If the Radio/CD output sensitivity is 2 volts, then adjust the amplifier LEVEL input to 2 volts.

If you are not sure what the Radio output sensitivity is, follow these general guide lines:
Turn the level control up slowly, till you hear distortion, then back off a few degrees on the control. If at any point your amplifier goes into protection,
you will need to turn the Level to the left a bit and then try again. If you reach a point where the output does not increase, stop turning the Level
control to the right as the amplifier/subwoofer combo has reached its maxx output in this application.

 

[sweefu]

Simply running your amps at minimum gain and cranking your head unit to max is not tuning the system... And yes there will be clipping at max on the head units...

I never said having zero gain and maximum headunit volume is tuning a system mate. I simply said I run zero gain on my speaker amp. You are taking what I said out of context, though the rule still applies that generally a lower gain is better for sound quality.

I am still a novice at car stereo, though I've been an enthusiast for over 5 years and have a few trophies for SQ competition, I built my whole system myself, my front stage consists of DIY components and I tuned it all myself - so I feel my input is still valid here.

 

[sweefu]

To the OP

Tutorial - Amplifier Gain & Crossover Adjustment - Forums - Mobile Electronics AU

Read this.

 

[MAG00]

It IS difficult for guys new to car audio. My mate's all thought they set their gains correctly and weren't listening to distortion but they were wrong. So many people can't hear minor clipping or mechanical speaker distortion and need to actually be shown it before they will learn.

If it's at the point where he is BLOWING speakers, then I'm fairly sure that the distortion would be very obvious.

Read the post that sweefu directed you to: read this.

 

[MAG00]

Dayum, beaten by sweef -.-