looking arround in the market and got some statement that sound quality is need EQ and some say EQ is an obligation. need your comment regarding this. is it true we can only rely on passive x over?

If you want SQ in a car, 31 band Eq is a must. Provided you have the experience to tune it. Passive or active is always fine. For me always love Passive. Won't want to waste too much time tuning a active set up.

in an ideal car, you don't need EQ... hahahha
but no car I have seen is ever ideal, whilst still being driveable,
get a good quality EQ (no noise, no distortion, high level signal capable) at least 31 bands, or 10 band parametric per channel (important to balance left+ right separately) or both in one )
tuning is careful and takes time to get right, but all worthwhile.
but remember EQ will not 'fix' a bad install, only help a good install sound great.

31 band? it means the only choice is pxa 701 hah? is it audio control not good enough? thing it time for me to look arround eq in the market . If i'm using PXA, does the is ti going to be digital sound isnstead of analog? i like analog sound since so natural. need your expert experinence guys

careful because when you shift the EQ setting too much, you change the phase of the frequency..

http://harada-sound.com/sound/handbook/process.html under "to eq od not to eq"

And Arvus speakers are linear and are available to the public now.. let me know if you want some - very competively priced

LOL the speakers might be linear - but that doesnt allow for room (or vehicle in this case) accoustics does it you might like to get your hands on an RTA and check you might find that a 10 band parrametric eq is good enough because you only need something with a very high Q or else you might need something with a very narrow Q so a 1/3 octave 28 or 31 band eq might be the only option.

In regards to the x-over well active x-overs are more sterile and probably more correct - but most of us preffer valve amps and passive devices because of their analogue warmth / coloration

they have been RTA'd in my car and have come up near linearity with a drop after 20k due to silk dome tweets and a nice big hump at 50hz due to infinity sub and enclosure..

and i have a PG 1/3 octave equaliser with a 7 band parametric on the headunit.. when i go competitions i have it on straight flat.. and the equaliser has not been hooked up yet.. i haven't needed to use it yet

behringer EQ (see tag line) is fully digital 24 bit/96kHz, 1U rackmount
It does the A/D internally with Burr-Brown (Texas) converters.
has dual 31 band EQ, dual 10 band parametric EQ, as well as many more tricks, and no noise.
you can get for about $450 or so.

I use a jaycar sine-wave inverter at the moment - no noise from this either.

Pulse-R the only problem with that is that its Behringer. Nothing against Behringer - I love their gear great value for money usually pretty good quality and no issues with warranty claims (use there rack units allot in Pro audio) - However they are known for being "noisy" units. Behringer tend to copy other brands designs using cheaper parts and make the units in say china instead of japan or USA for a cost saving - this in turn leads to a slightly lesser quality unit and if you are wanting to be winning SQ comps prehaps the additional possible noise is something you wish to avoid.

That said I know Marc looked at using one (if he ended up using it or not i dont know) a while back in his BMW and i have been looking into using one but I dont want to loose the cross over capabilities of my HU at the same time - decisions decisions

The unit you recomend and use does that have the FBQ system on it and if so do you use it - it would look pretty cool going like a g/a

well, I challenge anyone to measure the noise added to the system by the EQ.
I'm getting around -112dB noise from the H/U, and the EQ is well below that.

Audiocontrol, PG, Orion make digital EQs currently I'm using a PG 215ix and TEQ4 1/2 din so I have 15 bands and 4 bands parametric all analouge though and I have no noise whatsoever induced by these. Though I don't know why I bothered as no one within 1600km of me has an RTA kind of makes it a bit pointless really but what really annoys me is I can't set the crossover accurately on the 215ix for the fronts to 80hz (where I want it) as it is infinately variable so have to settle for my front amps 110Hz HPF.

oh, and I forgot to mention, the Behringer has RTA 61 band built in, just plug in a measurement mic (not expensive) and away you go!

Pulse-R I was not stating that it "will" be noisy just that they are known to make noisy / lemon units due to the fact that they are aimed at the "bulk" of the mid-large sized PA use. I'm looking at using one my self just trying to work out whats better an inverter or building a dedicated 12v supply as was mentioned previously on this forum. I want the use of a full 1/3 octave not a 2/3 or parametric - thats what the HU is for. Mind you im also looking at a reverb unit but i havent decided on that yet - just to give the cabin some space and a bit of a more "live" tone but i want it to bypass the sub because cars have enough sub range resonaces. i actually more just want the reverb on 1k (prehaps as low as 500Hz though to catch that driving electric guitar) on wards till about 6.5k. Obviously it will be set very dry because i dont want to sound like im in a cave but this will all have to be arranged by seperating and rejoining processed freqs and behringer seem to make the best value for money stable in an ever changing environment. If i was setting up my studio i would choose other brands but most higher end stuff in pro audio is not suitable for touring.

I personally dont like Audiocontrols Eqs i think they are a bit too wanky and not bare bones enough to do the job efficently

yes, I know some EQs are noisy, that's why I was making the point that the DEQ2496 isn't noisy.
as for the reverb, split the signal, band-pass it, run it throught the reverb unit, then mix back in post-eq, before the cross-over
should work ok, since the reverb is low-level, should be fine to do it analog.

Pulse-R you are a genius!!! so but using a full active x/over band passing the signals to the effects unit then using a small console (ie DJ mixer of some form) my idea will actually work... ...well in theory (so far) any way.

And now to goto see some people about buying some equiptment (or atleast borrowing for testing)

You don't have to have an EQ in a top sounding SQ install. If you want one - go for it, but it'd be near the bottom of my list of things to buy and try.

Komodo, for splitting / mixing the signals, it may not be necessary to buy DJ mixers and things, by just using resistors and level controls (20k potentiometers ) you can do the mixing passively and very very cheap.