ok, i was reading some posts and i became a bit confused. How do you compete for sound quality? I am a person that believes that SQ is subjective.. there is no 1 definition. Different people like to hear different things.. so how do you compete like that? just curious.
For SQ, you not only will need a system that can reproduce sound as close to the source as possible, you also need great imaging. You can't just slap on expensive parts and expect SQ. It has to be installed and configured properly. Since no car behaves the same to sounds, device such as RTA will be required to tune the system. You won't believe the equipments needed to produce great sound quality.
SQ catagories.. imaging, soundstage, noise floor, sound curve. These are mostly measureable factors, or easily audible and comparable. curve is measured on an RTA, as is noise floor imaging and soundstage you can tell simply by listening, and is mostly dependant on speaker positioning and aubible transparency.
Ideally, you use a reference system, and compare to that, looking for ideal transparency and realism from the system.
until glass breaks it all the way down (and corrects me): imaging is the audible transparancy that glass eluded to (starts w/good components), and the stage is from where the sound appears to be deriving. there is critical and annal attention to each of these in iasca sq. e.g., points awarded for how far in front of the windshield the signal seems to be originating and what instruments and vocals appear where in the stage. my positioning is in the doors and results in a sidebiased reproduction. it should hopefully be corrected by TA (time alignment), but that will likely be for the driver's seat only.
to reiterate what's been said, sound curve is a measure of response from 20Hz to 20JHz (audible frequency range for human hearing) at the driver's seat. This is measured using pink noise test tones, and an RTA, which graphs the response in your car to see if thee is any peak or dip points in the frequency range. Ideal response is "flat" where there is no coloration or overly bright or missing bands in what you can hear.
noise floor is basically turning the system volume all the way to zero and listening for any hiss or hum. If there is any non-musical sound in the system caused by interference, electrical issues like EMI/RFI, amp gains being mis-set, etc.. that subtracts from the score. Noisegates are often employed in studios or in high end systems to eliminate any sign of noise from the stereo system that isn't absolutely intended to be there.
imaging is fairly simple. This is your left to right stero separation. Good imaging should allow you to close your eyes and pick out where each musician was sitting during a recording session of a jazz track, or where a singer is standing during a recording session. If imaging is poor, you'll be able to pinpoint the location of individual speakers, or you won't get a good phantom center channel effect with a solo singing artist at center stage.. he or she will sound like the voice is coming from one side of the car or the other, or in the case of too much rear fill, stereo separation will float from rear right, to front left, making vocal location difficult to center on, audibly.
soundstage is the ability of an audio system to give you the impression that the band you're listening to is well in front of you, and slightly elevated as if on a stage. Poor imaging can draw the sound behind you, make it feel as if its in your lap, or down by your ankles, due to poor speaker balance, fading, or positioning.
Other factors that can affect SQ score would be audible distortion, or the inability of the system to produce a clean sound at volume, speakers bottoming out, coloration caused by enclosure ports or box tuning, overly accentuated bass from poorly designed or implemented crossover points and slopes, or overpowered subs in relation to the rest of the system, rattles or resonance in the car that's audible, ground loops or alternator whine, sparkplug clicking in the system caused by lack of suppression wires, a "live" sounding environment due to lack of sound deadening and reflections from large, flat surfaces like glass in the car... many factors can affect a good sounding system, or prevent one altogether.
It's a very different world from SPL events, whre all anyone cares about is how loud they can get regardless of musicality or if the system sounds good with music.
Well not as much as before. I removed my rears and used the holes as bass ports. Doubled up on the 6.5" components in the front doors as well as tweeters. If they're not tuned and balanced properly, it'll sound horrible. Speaker location is very important. My goal was to get as clear vocals and highs as possible, at the same time, clean and tight bass. So far, I can't complain. Any music with instruments sound very realistic.
"I am a person that believes that SQ is subjective.. there is no 1 definition"
It is subjective, but you'd be surprised how similar the top components sound when installed optimally. The best thing is choosing components that work well with your application, sounding good to you is important, but can only be achieved with a good install and that must be taken into account.
