SQ and nothing but. Being cheap isn't an option.

**reallyxxxxxxloud** · 05-08-2011, 10:39 AM

This is bits and peices from 3SI that I answered for some of my fellow Aussies. I'm sick of seeing the same dribble stated by people with some knowledge but not quite correct. Basically this is about your base setup - later I'll go into what you should be hearing as you tune it.

I want to put 6" splits in my front doors at some stage and was wondering is it worth replacing the rear 6"x9" with another set of 6" splits? I am running a sub 1200w Sony in low profile ported box running off a 400WRMS mono block Audiobarn [Dub Audio???] amp. Speakers running off the head unit.
Seriously You need the music to come from infront of you not behind (a sub is different as its non - directional).

You will get it loud but not staging nice with rears.

The money and time saved not buying/installing rears put into sound deadening and diffuser pads in the doors. This will increase sound quality and double your gear in output (no bullshit). Its not that hard - A winning system will be a powerful amp and fronts, plus a sub, sub amp and sound deadening. Plus with less gear you can buy better gear.

I learnt from day one @ 18 I bought my first set of speaker at $1000.00 and still use them 19 years later!!!! Diamond Audio Hex (Eton made). It took me about 6 months to find what I wanted by listening to a shit load of speakers.

I had a friends 8 yo girl get in my car the other day, she looks at the 18" sub then the fronts and says "the bass is coming from the front speakers, you would think it would come from the sub being that big" and then she laughed. What she didn't get was the car has no rattles and the brain can't localise the bass but it hears the fronts and thinks oh it must be coming from there!!!! With the 18" in my Hilux theres not much in the way of vibration. I like it when someone says how it takes your breath away... But its not a spl driven stereo more leaning towards clean sound but it still goes hard... Unfortunately I like SQL and its harder to achieve than just plain SQ. I like Mostly Heavy metal (Doom, Industrial, Black, rock), Electronic (Hardcore/Gabba, Speedcore, Terror, Hardstyle, Splittercore), Blues, Crunk, Reggae and well most thats not mainstream.... So its also hard to set it up for just one style. I have to compromise just a little.

I can get nearly any car to sound good, immaging, Staging, height, depth and width. But it could cost you a bomb to pay me to get it right for you, or it could just work straight out of the box... There is tweeking to do. For your 600awhp 3000gt you don't just buy a AEM ecu and it works perfectly when you have installed it. Same goes you have a base to build from.

well, I don't listen to bands really...and I've always liked it when a band has felt like they are sitting in my head (like when I have headphones on)

Well your not really into Stereo Hi Fi, you are more into surround sound. They both use a stereo system but are totally different and if you set the rears up with a 14ms delay you will get this awesome rear ambrient sound like its being reflected from about 5m behind, 30ms will give you 10m.

Why is SQ so hard to get - the reason being is most and I mean 90% of people have no fucken Idea, including most installers. I've heard two cars in my whole life that were perfect. Not one was mine.... I get close but not perfect.

I use to be Tech support, Rep, Service manager and built their demo cars for Fusion, was with them for 3 years. And Fusion has had some good sounding products (the cast basket powerplaint splits were great sound for the money (if your wanting cheap), not perfect but extremely good for the money especially for the average jo blow. Their old First series Jonah amps were to die for (Korean made) and their Jonah splits were quite good too but way over priced. The Encounter (I think theres a new lower range now, didn't know you could get worse than encounter yuk). Encounter (green cone) is cheap nasty shit and would even say it is worse than a factory speaker as far as sq. But because it has more power and with an amp you can drive it louder - people think its an improvement.

Old school selling trick I use to use when Managing Northfield car sound in Queensland Australia. Show the customer a set of speakers, then let them listen to the set you want them to buy but play it a little louder. 80% of the time they will choose that set because the brain thinks louder is better....

Now your stereo may sound good to you and your mates and thats probably because you all have really no real idea. Again no offence... And in saying that though sometimes being naive about something is good. Its like you'll enjoy way more concerts than me if we went to the same ones because I'll be upset by the sound at most of them.... Mostly because I'll pin prick all the engineers holes. And secondly you have a rear speaker that is more efficient, again pulling sound stage behind you. Third your bass will localise from your 6x9s not your fronts (that is if your sub is done correctly otherwise you will localise it at the sub)... And then theres Psychoacoustics...

Psychoacoustics is what its all about and I've studied it for 14 years - even bought lots white papers on research of the matter. Read Psychoacoustics - Wikipedia, It wont be easy for most to follow but it will give you a very good fundamental idea how it all works.

This is where the tuning comes into place. Its got nothing to do with setting up the gear (as thats a very very small!!! but still important part of it). ITS PLACEMENT, PLACEMENT, PLACEMENT.

Well...Your fucked straight off the bat, if you you wanting the sound for both you and the passenger. Reason is your not at home with the speakers miles in front of you with with minimal parthlength and arrival time differences . I always have set it up for myself (driver) as this will yeld the best you can get results... I paid for the stereo I should be the one enyoying it... but if your still determined to give it a go try this!!!

Mid bass in doors crossover at 200hz @ 24db to not drag down sound stage and high pass it at 125hz @ 6 db (80hz at 18db id no sound deadening) to blend it with Mid/Sub bass (Low pass sub at 80-100hz @ 24db, try different freqs as you may end up with a hump in some cars). Midbass/Midrange/Tweeter from the centre of the cone of each e.g. left to the drivers left ear (righthand drive car) then measure to the left ear of the passengers left ear, compromise between the two so both have a similar parthlength difference, then the same for the right (notice I didn't use the centre of the car, your not going to be driving around with both you heads in the centre of the car and the centre of the car will yeald different measurements again). You've just set up parthlengths for left and right but the arrival time will be out because for the passenger the right speakers will be further away than the left and this will cause phase shift-some freqs will be 180degs out of phase with each other, example- you have a parthlength difference of one foot between left and right midrange say at 500hz (wave-length of 2 foot) so one driver (the opposite diver for each listener) will be 180 degs out of phase at the listener causing a drop out in sound around this point, and this happens to be getting to a critical point in your imaging. If your path length for your tweeters are a shorter path length than the midrange you will pull the sound stage height down to your feet and if its to long it will raise it to the roof. If you do-not get this right you will not get the sweetspot... You cannot correct this easily, this is the point that kills it for a car let alone all the other problems like reflection, road noise and a yelling wife/kids .

Every fucken thing above gets thrown out the window now because of this below ... This can and will change its location for each driver. But above is written how you should start your system then go from there. Now you have set this up you will need to deal with the speakers on/off axis response. This no one can help you with this is to be done in car and is the make brake part of the install, as it has a lot to do with the cars reflections/speakers directivity and how good you are at correcting this by ear!!! Then you have eq tweeking to drop/up any small bumps/dips but really this sould be done via the install not the eq. Hope this helps Remember this is just a reference point (starting point) theres always to many varibles to deal with but its a good start!!! Heres some other shit about Active and Passive crossovers and how they affect it as well.

Passive, Active facts. - 3000GT/Stealth International Message Center

I'm going to be arrogant so don't try to argue me as I'll ignore you. If you have a question I'll answer it if I know. I'f I don't I'm only human and am not a know it all.

**reallyxxxxxxloud** · 05-08-2011, 10:42 AM

Part of why I hate oval speakers as the uneven cone distortion adds to the amplification of these effects...

Intermodular / intermodulation distortion

Intermodular or intermodulation distortion (IMD) is a form of distortion that introduces spurious signal components with frequencies that were not present in the original signal, based on the sum and difference products of the original frequencies. The introduced frequencies are often not related harmonically to the original frequencies, so the resultant newly generated frequencies are immediately perceived by human hearing as being non-musical; they generally sound annoying. Any system in the sound reproduction chain that is nonlinear - including signal processing - may introduce IMD to the output, but one of the most prominent physical sources are loudspeakers (and other pistone sound sources).

If a high and a low frequency note is played on a loudspeaker simultaneously, the effect can be heard most easily. A driver covering the entire audible frequency spectrum has a higher IMD than a multiple array of loudspeakers, each assigned to handle specific frequency ranges. Some high fidelity loudspeakers and headphones produce inaudibly low IMD. Also, when broadband signals are present, the IMD may be inaudible due to Masking effects of human hearing.
Causes

Harmonic Distortion

Any nonlinear physical source producing harmonic distortion also produces intermodulation distortion when there are more than one note is present. For example when there is a signal with two frequencies fa and fb driven through a system with a response H(t) which is a nonlinear function, such as a squaring circuit for example, the resulting output will contain the original (fundamental) frequencies and other frequencies as well that are some multiples of the originals: k_1 \cdot f_a and k_2 \cdot f_b. The order of distortion is the absolute sum of the multipliers.

Doppler Distortion

The Doppler effect is most commonly experienced when one hears a motor vehicle equipped with a siren or horn -- the pitch of the siren or horn drops noticeably as the speeding vehicle passes the listener. Doppler distortion in a loudspeaker sounds to the human ear as a warbling effect, usually of the higher of two frequencies generated in the same loudspeaker driver. A linear cause of this distortion is the Doppler distortion which occurs when two tones of largely different frequency are radiated from the same membrane. It is a linear form of distortion since its magnitude is independent of the amplitude of the higher frequency tone and the distortion increases linearly with the amplitude of the lower frequency tone. When the cone moves forward in the speaker due to the slow motion of low frequency sound, the pitch of the higher frequency component is raised and it is dropped when the speaker moves backward which is a kind of phase modulation distortion that causes:

Intermodulation distortion
Amplitude modulation
Phase shift

The maximum phase shift due to this effect occurs when the cone has a zero velocity at is maximum excursion while the maximum frequency shift occurs when the cone at its zero excursion but maximum velocity.