okie...today i had my system on RTA tuned. What suprised me is that after tuned my system sound damp nice. When got back to home and check the amp setting !!!! I was in shock, both of my sub amp (Xtant) and my front amp (Tube driver blue) gain are at minimum. No gain up at all. I call back to the shop and talk to the installer. He told me that my system is tune by the Xtant P500 and for SQ RTA which no gain is needed.

But....can u guys explain if he is correct ? This is the first time i heard the gain is at minimum. even the sub gain is at min. however, when i turn my deck volume up i can hear very crystal sound and tight bass.

[ August 10, 2003, 13:00: Message edited by: noidea ]

What was the problem again? Amp gains should ideally be at the lowest setting possible from a signal to noise perspective, it sounds like whoever tuned your car did an excellent job!

I have 4 amps in my system and all have gains on absolute minimum, all sounds fantastic running a set of Focal Utopia 165W3's and Soundstream SPL 160sub (and some rear fill)..

RTA issue: In the CAAASQ format there is no mention of RTA measurement. I have a DSP with a 31band EQ in it but also bought a 32 band EQ just so I could fine tune system for RTA measurement under old IASCA system, it allows me to get a 37 every time. I wish i'd known that there wasn't going to be this measure, i could have saved $1k and made install eaiser.

Why did they take this measure out of the new format? I would have thought a system with a a flat frequency response would have been a good measure to have in a SQ event (even though I know a flat response doesn't actually sound all that good)

37/40 is actually not too bad....my system achieved 31/40 on the RTA....I lost 3 points at the low frequency <100Hz and 2 points around the 800Hz. I wish i could have borrow the RTA and tune it myself....The shop tune for me seem busy and that day alot of car booking for doing other stuff....so this only limit 2 hrs for tuning my car....i know if i have the RTA and tune it myself i can have better result...i wonder if i can loan a RTA machine or something.

Hutch, Yes the gain is in absolute minimum....but i wonder when the gain is at min will the amp produce any power at all. Nowaday, there is no competition based on the RTA. Today for an SQ competition only based on ears rather than RTA. Which from my experience i would think that by using RTA is the best measurement for SQ.

The problem is the RTA does not tell you the difference between the on and off axis response, as well as all of the many reflections you will get in a car.

If those problems were removed, then yes a flat RTA response would sound wonderful..

noidea - If it sounds good, then whats the problem?

BTW, these days with higher voltage preouts and amplifiers that can put out more power than the speaker really needs to get loud, then it is quite common for people to set the gains at minimum.