Nismo audio upgrade- critique my planned setup

2fast4thelaw

I had to heavily paraphrase to keep it from being a book but I will touch on your notes.

What i first was trying to say is I did not change the slope of the crossovers. Also Phase and slope only directly affect each other in simple passive crossovers without phase compensation. Any decent passive crossover will have phase compensation. In my Focal crossovers they compensated for that shift so I had to alter them.

Also since I have my own software I calculate time alignment by distance between tweeter and mid woofer becasue its a more stable constant since once the drivers are installed they will never move.

A Zobel network is already designed into the Focal passive crossovers because the Focal tweeters are actually 8 ohm and the woofer is 4 ohm. I altered the values in an attempt to undue the phase compensation that was designed into the crossover which put me exactly where I wanted to be at 270 degrees off-axis.

I left the mid woofers as they were (off-axis) as I only needed to alter the tweeters in my installation. I did this to keep it less complicated becasue I knew I could use my eq to blend them.

I wasnt using the EQX to tame individual speakers but to tame the peaks at each octave. I also first tune the system by my ear as what sounds best to me. I then record my settings as my reference point. If and when I have my car RTA'd for competition I can record those settings as a competition reference point so I can go back in forth. Perfectly flat is not always ideal for all music for everyday listening at least for my tastes.

Remember, there are a hundred ways to skin a cat. What I did made a big improvement and greatly enhanced my imaging and overal tonality of the system. If I could have in hindsight I would have used the 3-way Focal poly kev set and had even more improvement. I wanted to keep the stock appearence and that would have been nearly impossible.

__________________
To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.

speedfreak28

LOL funny you use the metaphor theres more than one way to skin a cat, It was exactly my thought when typing my last response. It just seems that you're taking the longest way to achieve the results, I was under the impression you had the car RTA'd. You can calculate all you want but without figuring out the vehicles internal volume and resonant frequency the crossover design was just a guess. This is why I prefer an electronic crossover. Essentially all the componets you changed in the crossover usinga program are a guess without measuring in car with an RTA. You cant figure out the phase diffence form the reflective materials without one.
Id scrap the passives all together and maybe use a DQX for all your tuning. There are som any in car variables that effect overall phase and stage height that in a competition SQ vehicle you have to be able to make small adjustments. In my truck I had been running a Clarion DRZ9255 and a DQX to take care of those issues. Now for a non competition vehicle, the passives will do the job just fine.
I would be interested in hte program you use Ive used a few different programs but theres always more to learn which was the original point I was trying to make to you...

2fast4thelaw

My methodologies may not be very efficient and you are correct, I have no way of calculating the inside of the car or measuring the refraction of sound from different materials. Much of what I have done is an educated guess and I am no where near exact but I am in the ball park.

The reason I chose to retain and modify passives is becasue I have years of experience playing with them and I enjoy doing it. Most of my experience comes from home audio which follows the same basic designs, but car audio enviornment throws a twist which makes it a challenge I couldnt resist.

As far as software is concered, I didnt like anything I found so I wrote my own software and over the years built upon it. I would be more than happy to share it with you but its not compiled and I dont have a compiler so I can't package it into a neat little installation file.

I have some really old programs that are more basic that were done in excel that are usefull. The crossover calc is only 1st and 2nd order crossovers and its basic but its usefull for building custom passives.

__________________
To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.

2fast4thelaw

This site will not let me upload .xls, or .rar files. If you want them, pm me with your email and I will send them to you.

__________________
To the optimist, the glass is half full. To the pessimist, the glass is half empty. To the engineer, the glass is twice as big as it needs to be.