Some System Tuning Questions

I am in the process of retuning my system, setting eq's, gains, you get the idea.
But while I feel I have researched a lot and have a pretty good understanding of things, I am also getting spun around and lost.

The components:

WS420SQ (no deck used)
PPI 900.4 (tower)
PPI 600.2 (inboat)
Memphis 500d (sub)
Rev10 (1 pr)
Db651 (2 pr inboat)
Alpine Type X (1 under helm)

So here goes my list, placing the questions in a manner as to try to work through the system as it flows

(1) I run a WS420sq, so the input is solely based on the aux 99.9% of the time from a phone signal. What I am getting frustrated with is trying to contain this apparent variable of the phone signal output level. I know that if it is turned all the way up- the speakers distort very quickly. I presumed it was because the signal was clipped from the phone. However I hooked up the output to an oscope and ran 0dB test tones from 20Hz to 10kHz and with the phone volume at 100% it never clipped the sine wave? So it would seem to me it’s a clean waveform output even at full tilt. So why then does it seem to immediately sound like crap when played through the system?

That said- how can I if at all “safeguard” my tuning under consideration that it will see music from various devices with presumably different levels of output amplitude into the WS420? I assume that if I set the all gains with my phone at say 80% then anything above that from a different device will nullify the gain structure and run the risk of distortion and failure. Is this true? Is there any work around or advice on this?

(2) Does the WS420 have a maximum volume before clipped signal like a normal head unit does? Or does it only attenuate the input so it is clean to full volume output?

(3) When setting the amp gains- what level should I have the volume(s) on the 420 set to? The master, tower, inboat & sub (each has independent amp)

(4) Following the volume settings for gain matching- do the 4 crossover channels (tower, inboat) matter while doing this? If so, where should those be set to?
Say the gains are set with the crossovers on the 420 centered (at 12:00 visually) then do I run a risk of blowing the speaker if I turn the eq’s up after the fact? In that notion, would you recommend using the amp xovers to “safeguard” the speakers in a worse case volume with the 420 turned all the way up on the 4 settings? Or does that not apply like that.

As you may be catching on to- my biggest concern is to have everything set in a manner to get max output when I so please, but in a safe and clean manner to minimize speaker destruction. Last summer I fried one of the rev10s which I am most certain was the result of running for a hard day with a badly clipped input signal. So I really want to understand things and not repeat this mistake.

And yes I realize I am a new member, so I have no real credibility per say. I have been reading this site for years, just didn't seem to have much to contribute in the past. Certainty could use some input / experience / suggestions now though

I'd turn your 420 volumes up per zone as your setting gains per amp obviously do them all separately so you can hear distortion per zone and I would do this all with your device,phone,all the way up. That's how I figure it would be easiest.

http://content.abt.com/documents/546..._WS+420+SQ.pdf

Page 5 and 6 on there tell how to tune the EQ. As far as a phone input goes, I'd say use your phone as if it were the head unit. Just turn the phone up to about 85% of the volume, and know not to go above that. No kids touching the stereo.

If you're this concerned about tuning, I"d recommend a SMD DD1. That's a distortion detector, but at the same time requires a cd player for the test tone disc.

An easy, very shortly worded explanation here is this:

Start with amp gains all the way down.
Turn phone all the way up, turn pre-amp volumes to about 3/4, all tone controls flat, EQ on phone or device turned off.
Start adjusting the amp gains by ear. It sounds like you know what distortion is, so that's what you go to.

Xover - sub should be low pass, around 80hz and down. Boat speakers should be 110-150hz on high pass, Rev10's should be around 100-110hz high pass. That's generally around where I tune most systems we do. 99% of it is by ear - but still assuming that somebody's gonna **** it up when they get drunk - so there's a little compensation there as a precaution.

I second what JONYB said however, if you would like to use the DD1 and do not have a CD player, you can always download the test tone tracks online and load them into your phone. There are tons of sites that have them.

Originally Posted by jonyb

If you're this concerned about tuning, I"d recommend a SMD DD1. That's a distortion detector, but at the same time requires a cd player for the test tone disc.

An easy, very shortly worded explanation here is this:

Start with amp gains all the way down.
Turn phone all the way up, turn pre-amp volumes to about 3/4, all tone controls flat, EQ on phone or device turned off.
Start adjusting the amp gains by ear. It sounds like you know what distortion is, so that's what you go to.

Xover - sub should be low pass, around 80hz and down. Boat speakers should be 110-150hz on high pass, Rev10's should be around 100-110hz high pass. That's generally around where I tune most systems we do. 99% of it is by ear - but still assuming that somebody's gonna **** it up when they get drunk - so there's a little compensation there as a precaution.

Thank you for the tips. I must have forgot to mention but I am using an oscope to check the sine wave. So far I have used a set of tones from Spotify through the phone