[dinu2506]

Excellent job, congratulations. I'm sure it must be satisfying. The tweeter pods look fab. Did you get it fibreglassed?
You could do something to get a better finish on the console around the screen edges. Looks a wee bit crude.
Congrats again for a great DIY.

[ST7677]

Thanks Dinu, yes it is very satisfying. This was a big project with lot of aspirations, and now that they are met, there is kind of a void questioning what next?

I am waiting to get the right paint to do final finishing of the dash panel. However the interim finish itself does not look that bad to the eye, it's the camera flash light which has highlighted the imperfections...

The tweeter pods are fiberglassed and covered with rexin.

Best part is that the start up time on this setup is hardly 3 secs.

[frankmehta]

ST, after using Centrafuse 3.0 on my home computer all these days, I feel it's interface is a TAD antiquated and pretty poor for for large music archives. Is this true? Or are you happy with it?

[ST7677]

I agree, Centrafuse's interface is not excellent for large music archives.
It is little difficult to get and play what you want precisely and quickly. You are finally able to do it but requires more clicks than what I would like to do.

Look you can change by trying different skins for Centrafuse. So far I have not bothered, after few months probably I will get bored and change it.

Navigation engine is also not up to my liking, I rather user Destinator 9 independently. (only disadvantage is that the music does not turn down automatically as with inbuilt Navigation).

Overall, these are small quibbles, and I am still very happy with it.

[mukeshgoel]

Hi.

Any idea what is the latest price for a 2-din dash panel kit like this (mirror image) for the Civic? Also if anyone knows from where Can I get it Delhi/NCR ?

[ST7677]

Earlier it was 12k, but now I hear that now it has become quiet cheap 3-4k, I guess.

[mukeshgoel]

Thanks.

I hope the quality has not gone down. Will try to find one in Delhi market in case I plan to change my HU about which I am quite confused.

[ST7677]

hey, by any chance would you have a pic of your pc mounted under the seat? I found out a case (with PCI) which is 288 X 295 X 64 and another one which is 252 X 88 X 230, I guess one of them would fit. wanted to see how you have mounted the case.

I do not have a pic of the CarPC under the seat, but I can describe it for you.
My case is 270x 265 x 90mm, which is just kept under the front passenger seat. 90mm is the max height you can squeeze in there without affecting the seat movement (or cutting the carpet).

The available space under the seat is about 343mm W x 178mm D x 90mm H. So in my case, the case shows out of the seat (is not completely covered by the seat) by about 3.5". Besides aesthetics, it is not a functional / practical issue as legs are anyway in front near the firewall and this space is unutilized. I have covered it with the carpet from front. The case could be squeezed into 7.5" depth (instead of 10.5" that I have) but since I am running a C2D proc and do heavy processing, so I wanted a well ventilated case. I have some 3" of space virtually empty inside, available for future hardware add-ons.


In your case, while both cases will fit under the seat, I would recommend the 252 X 88 X 230 size case, as height wise it will fit under the seat and it will be only 2" protuding from front.
From my experience, ideal case size would be 280 x 191 x 85mm, so try to get something closest to that.

Also before buying the case do plan what all you want to stuff in there and plan how it will fit in. Like PSU size, HDD mounts, Optical drive (if you want). Do check how all wiring will come out and space around for connectors (you want all connections going in and coming out perpendicular to car movement direction, i.e. towards the door, nothing towards car front or back sides). I overlooked that point and had to relocated my PSU due to this.

[ST7677]

I have started with Frequency Response tuning of my car.
I have IKMultimedia Advanced Room Correction (ARC) software and a pre-calibrated mike along with it. Using it with Rolls MP13 preamp. ARC has world renowned Audessey multi point EQ auto adjustment to flatten the room response of speakers.

Started the measurements last weekend and that's when I realize that process of measurements in car is extremely difficult and it will require lot of experimentation to get the right results. As a result of various reflections and nodes, the frequency response changes significantly with slight movement of microphone, so will have to research more of spacial averaging and gating window for measurements.

Anyway, since ARC is made for use by dummies, so started with that. My quick and dirty measurement with ARC turned out to be quiet dismal. The output VST plugin had a very early low frequency roll off and lop sided output. Though better imaging was upfront evident.

The problem I guess has largely happened as ARC seems to bypass the entire Virtual Audio Cable (i.e. bypassing all volume controls) and blasts sound sweeps at full volume. After the first four sweeps, I had to literally use ear plugs before taking 20 additional sweeps and still I had ear pain that night.
I was also worried about burning up my speakers, as I could feel the components vibrating at my leg with each sweep, and smell the voice coils getting hot!

ARC suggests to run the measurements at normal listening levels, this was obviously much much more than that. The speakers were playing beyond the limit, screwing up all the measurements! So no more using ARC till I figure out how to control the volume...

[ST7677]

Inquisitive as I am, my mind was wandering, and I decided to do the measurements and calibration manually (that's where all the fun is). After doing some short reading on spatial averaging and time windowing, I started taking measurements of what’s there in my car.
Now, without sounding like bragging, my car does have some good equipment and is installed & tuned by one of the best person available in Bangalore, so I was expecting a good outcome, that is till I read about the limitations in the car and in reality how bad is what we normally think is good

Below are the 3 power response curves of Front Left Component, Front Right Component and the Subwoofer. The graph is smoothened to 1/3 Octave. As one would expect (after reading up on car audio) there are huge holes in the frequency response.

[ST7677]

I took the Front Left Component channel (which had largest variation) and started equalizing it. The image below shows the before and after frequency response after using 31 bands (out of 64 available) for equalization. This was only a trial attempt and I am still learning to use parametric equalizers, so I am sure it can be better than this.
I would have like to share how the equalizer looks, but unfortunately I do not have Print Screen button on my portable CarPC keyboard, so that will have to wait.

I decided to take -18db as the center point and eq-ued everything around it. Started from left side and moved right. Looks like I have managed to get most of it under +/- 2db range.
That drop at 135Hz was not there when I was passing that band but seems to have got sneaked in later and got missed. The high pass crossover for front is set at 92hz.

All measurements are Single gated 1/3rd octave smoothed frequency response with time gating of 10ms to reduce reflections.

[ST7677]

This is the right side response before and after correction. Do note that the level matching between right and left is done using another plug in which is not active in these images. (I had basically turned all other plug ins off).

[ST7677]

Previous post was a 1/3 db smooth graph, I am next going to attempt 1/24db smoothening for a bench flat response!

The correction equalizer for that is in the image below. I had to use 128band equalizer to map this correction curve! Yet to hear how this will sound. Did this while sitting at home while controlling my car pc and taking in car measurements over internet.

BTW, This stuff is amazing - I can switch on my car PC, set up the measurement equipment and lock the car and come back home. From convenience of home over internet I can take measurements, do tuning, etc, monitor the battery discharge and when done switch off the whole setup from home itself.

[ST7677]

So what are the listening impressions? (not applied the 1/24db correction yet)
1. One thing that is immediately noticeable is that the hole in the frequency response which I could feel earlier (and was very very evident in the uncorrected plots) are now covered.

2. And moreover the sound imaging has just opened up so well. I can now close my eyes and consistently point in the direction the instrument in playing from! It's awesome improvement, considering that in Civic stereo imaging is really difficult to get (due to the cab forward design and the speaker placements).

3. The sound has become more smooth and buttery, pleasing to ears, (this can purely be psychological also. As the moment I saw the raw uncorrected graphs, suddenly my audio started sounding so crude to me), lol


Next I am planning to add a 4th equalizer for the sub-woofer. The three ones already there are.
1. Master Eq - to set the target curve (listening flat is not fun, is it?)
2. Left side front component equalizer to make their response flat
3. Right side front component equalizer to make their response flat

Will be adding 2 more eqs for rear speakers later. That will make total of 6 equalizers - 4 of 64 bands and 2 of 128 bands.

I am wondering what frequency to transition from Components to sub woofer? As you can see the components can really play down to 50hz flat. (so far I have not equalized them below 100 hz as my current cut off is 100hz, but I am planning to go down to say what? 83hz???

[ST7677]

Not a single response in last 40 days, not sure if this blog interests any one???