Info on tuning the car please

[TDot 10+ year member]

Ok, I'd like specifics on how to tune the car. I have everything set up, just have to swap out the focals for the hertz when they get here next week.

I'll have a dmm, computer, and mic.

1/ how loud/low should the pink noise be when I'm eqing the car with the mic. Since individual freq response will be different at different spl, should I do this at mid volume, or average listening volume.

2/ do I need individual freq tones if I'm using pink noise overall? If so, why?

3/ do I tune/eq each speaker individually, front and back individually, all speakers minus sub, or all speakers and sub together?

4/ besides this question seemingly dumb, should my main eq and t/a be with the mic at the center console or at the drivers head rest?

5/ my sub is in the trunk, should I point it up, towards the seat, or towards the back? I'm looking for a tight hit. I kind of doubt it, but does it make any kind of difference?

6/ my front stage I'm cutting at around 150-250hz, I don't know yet, how much of a difference is the factory 18G vs upgrading to 16G wire? And please don't just regurgitate "it'll make a huge difference", "it will sound better", "you need to do it". What are discernible and audible difference? Will the highs sound brittle, will it distort, will it crack, will bass (if I was to use it) not punch through? It's running 8 to 10 ft. (I just can't imagine a discernible difference)

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[keep_hope_alive Premium Member]

Ok, I'd like specifics on how to tune the car. I have everything set up, just have to swap out the focals for the hertz when they get here next week.I'll have a dmm, computer, and mic.

1/ how loud/low should the pink noise be when I'm eqing the car with the mic. Since individual freq response will be different at different spl, should I do this at mid volume, or average listening volume.

2/ do I need individual freq tones if I'm using pink noise overall? If so, why?

3/ do I tune/eq each speaker individually, front and back individually, all speakers minus sub, or all speakers and sub together?

4/ besides this question seemingly dumb, should my main eq and t/a be with the mic at the center console or at the drivers head rest?

5/ my sub is in the trunk, should I point it up, towards the seat, or towards the back? I'm looking for a tight hit. I kind of doubt it, but does it make any kind of difference?

6/ my front stage I'm cutting at around 150-250hz, I don't know yet, how much of a difference is the factory 18G vs upgrading to 16G wire? And please don't just regurgitate "it'll make a huge difference", "it will sound better", "you need to do it". What are discernible and audible difference? Will the highs sound brittle, will it distort, will it crack, will bass (if I was to use it) not punch through? It's running 8 to 10 ft. (I just can't imagine a discernible difference)

excellent questions!

1. i keep my pink noise around 70-80dBA. test at various levels to look for linearity.

2. after using pink noise for years, i'm going to start using sweeps. i developed tracks that sweep slowly. then i'll monitor with the RTA on "Peak Hold" and see what curves I get.

3. i do all speakers separate. then i start combining. with TrueRTA you get 20 presets. I save each run, taking notes, then compare and analyze. if you see a dip appear when you combine then you have phase issues.

4. you put the mic where your head is. you also want to sit in the seat (quietly) and move the mic around your head during the measurement. figure-8 patterns, ear-to-ear, etc. to take an average over the listening area.

5. makes a huge difference. placement is everything. where it faces determines what interference you will hear. keep in mind that you don't just hear the sub directly, but every delayed reflection also. rear facing in the rear corner yields the flattest response. forward with a baffle to totally seal off the trunk also works great and is my favorite.

6. wire won't make a difference. i run my front stage down to 50Hz. but i have a 3-way active setup so my midbass is dedicated and midbass excursion doesn't affect upper midrange. this is not a concern with underhung drivers which can handle both midbass and upper midrange. you want your front to run as low as possible to get bass to sound like it comes from the sound stage. there is a lot of kick drum information above 120Hz.

 

[TDot 10+ year member]

1/ great, another test tool i have to buy for this task lol. does the truerta show dba/spl level, or do i have to buy one of those tools.

2/ why?

3/ that is a great idea of how to see phase issues. how often do you see phase issues in particular frequencies vs the whole speaker? and how would you go about fixing frequency phase issues? that doesnt really seem fixable to me.

4/ great point! i would have never thought of that even though i really notice differences in tone and level when shifting from side to side in the seat.

5/ roght now i have it facing up. im going to try it facing forward.

6/ true the kick frequencies do go above 120, even 300, but right now im experimenting with the stage and im kind of liking the front with no bottom end. different from anything ive beard before and really making the vocals stand out. right now im playing with the rear stage picking up the mid bass of things...the to end of the kick and base.

 

[TDot 10+ year member]

Bump

....Also, when setting the voltage do I need to have the full load on the amp? If so, how do I do that without speakers connected?

 

[keep_hope_alive Premium Member]

thanks for the heads up, anyone can PM, quote, or mention me if they want my input. i can't see every thread and i don't go back and look at them (not enough time).

1. TrueRTA is an RTA - so it shows a plot of dB vs. frequency.

2. pink noise is just that - noise. i expect sweeps to identify resonances and phase issues more clearly.

3. phase issues always present at specific frequencies - either from constructive or destructive interference, or phase issues with crossover points/slopes. you can fix the latter with polarity. the former requires adjustments to aiming or the environment.

you can set gains with the amp unloaded