[makkan00]

Audio upgrade is a bug like modding bug and when it starts, it hardly finishes. Some people use their brain and limit themselves to reasonable audio upgrade, but when you have DIY bug and you can add / replace drivers / speakers/ components out of BMW, audio upgrade hardly stops. And unfortunately, I fall into that group (other than Kaigoss, Rudz & Mob17).

My journey of audio upgrade is very lengthy and I’d like to share it as if somebody wants any information on the stuff which I have used in the past.

Mak Stage 1:
I started my Audio upgrade with JUST hi-fi coding and L7 under seats subs. Later, I upgrade my front and rear mids to different brands including vibe slick V4, L7 mids and some good German mids with the addition of Kenwood amplifier. I also replaced L7 under seats with earthquakes (SWS-8s). That was my stage 1 upgrade and it ended with the addition of JL XD 400/4 instead of Kenwood amp. I moved to JL amp as it could take differential balanced input (low noise) with no requirements of LOC.
During stage 1 upgrade, what was different to standard system?
HU coded to hi-fi
Addition of amplifiers
Addition of different speakers
Addition of different under seats
Outcome learnings:
Use those amplifiers which can accept differential balanced input to avoid any noise in your sound system and stay without LOC.

Mak Stage 2:
During the stage 2, I replaced XD400/4 with 600/6 and powered the rears speakers. I added JL 12W7 (as Infinite baffle) with JL Slash 1000/1 V2 amplifier and 2 Farad capacitor. It all worked great and sound was great for a stereo system. However my car lacked time alignment and suffered fromSQ loss.
For experimentation purposes, I bought JL MS-2 (2 channel DSP) and that worked great in my car. One of the forum member tested it my car and commented that MS-2 really tweaked my sound system to its optimal level. The outcome was to go for DSP.

Along with the DSP, I wanted to go active (all crossovers setup electronically and not with passive crossovers). So, I thought of changing the HU for stage 3 upgrade.

During Stage 2, What was different to Stage 1?
6 channel amplifier
Addition of subwoofer with dedicated amplifier
Addition of Capacitor
DSP trial
Outcome learnings:
-I have tried different methods of subwoofer installation and IB worked excellent for me.
-Having stereo sound system is great, but DSP is good addition to your sound system if you are audiophile.
-1000/1 V2 and 12W7 is way too much for my sound system (considering IB installation.) I could have lived with a sub having 700-800W RMS.
-With all these upgrades, I needed better mid drivers.

Mak’s Stage 3:
Now, this is where we are. My stage III kit consists of
HU: Pioneer P88RS

Compatible Ipod adaptor

Front Mids: Focal 100 KRS

Front speaker adaptors

Under seats: Earthquakes (SWS-8)

Steering wheel control stalk adaptor and Fakra harness for aftermarket HU
JL XD 600/6

JL Slash 1000/1 V2

JL 12W7 as IB

I have tested pioneer HU extensively to establish its clip free abilities and made that as a reference to set the amplifier gains.


My installation started with fitting the HU in the network mode where it gives you HI, MID and LOW signals from HU and I fed that to amplifiers. Aftermarket Fakra / harness worked without a fault (PS: I do not have reverse parking sensors).
Next task was to setup the door speakers with adaptors. Although the adaptors are good in size, but their holes fitment for screws are poor.


I have to widen the screw holes so the screws can sit square / flat against the adaptors.


This photos shows your different ways of fitting screws


I used the HU output to run front tweeters, 2 channels of XD 600/6 to feed Focals (50-60W each and they get bloody loud) and other four channels (in bridged mode) to feed SWS-8s (150W each). They were setup with Oscilloscope (O-Scope) and multi-meter.

I had to use the LP filter on sub amplifier and HP filter on SWS-8 to separate their frequencies. (Semi- Active Sound system)

I have used pioneer auto time alignment and auto equaliser, and HU took approx 5 minutes to setup this for me.



Sound changed drastically after this and with fine tuning following are parameters;
Tweeters: HP @ 4KHz with 24db / oct slope and normal phase
Mids: Band passed for 200Hz- 4Khz
LP @ 4KHz with 24db / oct slope and normal phase
HP @ 200 Hz with 24db/ oct slope and normal phase
Low / Sub:
SWS-8; band passed for 70-160Hz
LP @ 160 Hz with 24db / oct slope and reverse phase
HP @ 70 Hz with 12db / oct and reverse phase
JL 12W7 LP@ 70Hz with 24db / oct and reverse phase
Infrasonic filter on at 30

After setting up the system, I must say that this is the best sound system I have ever heard IMO both in terms of SQ and SPL. Fidelity of sound system is excellent.

During Stage 3, what is different to stage 2?
Upgraded mid drivers / speakers
Aftermarket HU with built in DSP
Learning outcomes:
-DPS made the sound best considering my drivers and BMW internal dimensions
-Aftermarket HU worked way better than BMW HU
-Earthquakes can also play mid bass if you feed them properly but within 160-180Hz max. You can go further up but they do not play with the authority there.
-Fidelity of aftermarket HU is way better than BMW alpine HU.
-Hole in the BMW doors are big and 5.25 speakers with customized spacers may fit there. How much are you going to gain by additional 1.25 inch? This is a good topic for discussion considering the dispersion factors of the cone area at higher frequencies especially when OEM speaker location is off the axis.



Thats it for the time being till I get sometime and play more with under seats.

[Hopeful]

Don't you normally sandwich the speaker between the adapter ring and the door card?

Did you need to remove the grilles or was that just to illustrate the fitment?

[makkan00]

Originally Posted by Hopeful

Don't you normally sandwich the speaker between the adapter ring and the door card?

You do especially if your speakers are deep.
Problem was these adaptors, as they did not allow the front mounting on these. (holes are small) So I ended up having rear mounted speakers.

Originally Posted by Hopeful

Did you need to remove the grilles or was that just to illustrate the fitment?

Just for illustration purposes. I wanted to see and compare.

[kaigoss69]

Good job and nice write-up! You know what's next... replacing those Earthquakes!

[makkan00]

Originally Posted by kaigoss69

Good job and nice write-up! You know what's next... replacing those Earthquakes!

Thanks buddy. You are spot on.
I bought some Rainbows 6.5 mid bass to fit but earthquakes played so better with proper power so I did not go for rainbows underseats.

I may go for 8 or 9 inch underseats....hunting is on

[sohlman]

Well done you.

I look forwards to my next listen

[nelson29]

Nice write up! I have a pair of the 8" rainbow midbass for sale on the classifieds.

[Hopeful]

Originally Posted by makkan00

You do especially if your speakers are deep.
Problem was these adaptors, as they did not allow the front mounting on these. (holes are small) So I ended up having rear mounted speakers.

That's a shame. I don't suppose that you made a note of the internal diameter of the adaptors did you?

[808MGuy]

Those adapters seemed like a very poor attempt at copying the one I used to make. The issues about the screws was something I ran into during testing which is why I used undercut machine screws which have flat surfaces both at the top and the bottom. I'm not sure how the alignment of the holes could be messed up since the spacing is common.

[kaigoss69]

Hey Mak, just wondering, was the phase adjustment manual or did the auto tune algorithm do that? As both the midbass and sub are phase reversed, they are in phase with each other, but out of phase to the mids/highs. The underseats and sub being in phase makes sense since that is what I have found works best with the IB setup. The midbass to midrange reversal working better however is news to me. Can you please elaborate on what difference in sound you noticed (if any) with that adjustment? Thx!

[mistryn]

how much power are you feeding the earthquakes?

[makkan00]

Originally Posted by nelson29

Nice write up! I have a pair of the 8" rainbow midbass for sale on the classifieds.

Nelson
If I was in your country, I may have given them a try.

[makkan00]

Originally Posted by Hopeful

That's a shame. I don't suppose that you made a note of the internal diameter of the adaptors did you?

I was in a rush to listen to Focal, so didn't consider measuring the diameter.
You can send a message to this seller and ask him.

[makkan00]

Originally Posted by 808MGuy

Those adapters seemed like a very poor attempt at copying the one I used to make. The issues about the screws was something I ran into during testing which is why I used undercut machine screws which have flat surfaces both at the top and the bottom. I'm not sure how the alignment of the holes could be messed up since the spacing is common.

Your spacers are far better than what I have bought. The are centainly a copy of your design.


Has anybody tried to fit 5.25 inch speakers?

[makkan00]

Originally Posted by kaigoss69

Hey Mak, just wondering, was the phase adjustment manual or did the auto tune algorithm do that? As both the midbass and sub are phase reversed, they are in phase with each other, but out of phase to the mids/highs. The underseats and sub being in phase makes sense since that is what I have found works best with the IB setup. The midbass to midrange reversal working better however is news to me. Can you please elaborate on what difference in sound you noticed (if any) with that adjustment? Thx!

Kaigoss
HU has abilities to tune and equilise the whole system. I read a post by VP electricity where he used RTA and found that underseats were louder when fitted in reverse phase, as they complemented the sound waves of mid better in reverse phase (I guess).
I was going to try it but though to do it with stage 3 upgrade.

To my surprise, this HU has reversed the phase of underseats automatically and that has happened each time I tuned it.
I guess due to being under seats, and playing lower frquencies, sound waves from underseats (in reverse phase) are more in sync with mids and reach to listener at same time as frquencies of mids reaches.

Since sub is fed by the same channel as underseats, it is also reversed.

As my HU allows me to reverse these settings, I have done following further experiments.
Mids: normal phase
Underseats: normal phase (reversed set by HU)
sub: normal phase

There is a delay in mid bass / bass if I do that, more noticeable from the rear sub. To sum up, sound is not coherent.

I have done the same as above but with the sub in reversed phase (from the amp settings). Sounds get terrible. Tansition of sound from underseats to sub is messed up.

I read somewhere that time allignment matters upto 2Khz and after that it become meaningless due to high frequencies. I am not sure how true is that, but it clearly emphasis the importance of time / phase allignment b.w mids, underseats (mid bass) and sub bass.

Hope it answer your question.

[makkan00]

Originally Posted by mistryn

how much power are you feeding the earthquakes?

For reference, following are the power rating of what each driver is getting;

Tweeter: Approx 20-22W each
Focals: Approx 46-50W each (and they get bloody loud)
SWS-8: 150W each
JL 12W7: 1250W initially (mega bass), but I have reduced it to approx 800W.

[taibanl]

so...

1) why do you have an underlap (gap) from 160-200hz?
2) interesting that you have a 12dB slope on the underseat HP but a 24dB slope on the sub low pass... the 12dB slope is a 180 degree phase shift.

[kaigoss69]

Originally Posted by taibanl

so...

1) why do you have an underlap (gap) from 160-200hz?
2) interesting that you have a 12dB slope on the underseat HP but a 24dB slope on the sub low pass... the 12dB slope is a 180 degree phase shift.

Ha, I read right over that! I'm guessing he did not want to bring the SWS up that high. Sometimes a gap is ok or even desirable, especially when you're having phase issues at the crossover point. In this case though I'd advise Mak to bring the Focals down to 160 - 175Hz, they can do that easily with a 24dB/oct cut-off.

[makkan00]

Originally Posted by taibanl

so...

1) why do you have an underlap (gap) from 160-200hz?
2) interesting that you have a 12dB slope on the underseat HP but a 24dB slope on the sub low pass... the 12dB slope is a 180 degree phase shift.

1) Do you really think that there is a gap? If you look at xover graphs, 160 and 200Hz are still meeting but possibly at -3 to -6 dB IMO. So technically, there will a sound in those frequencies but not as loud as other frequencies.

And, I am already in a process of changing my underseats to something different which may be able to play upto 200Hz.

2) I'd love to have 24dB slope on the underseats, unfortunately, XD600/6 can only provide 12dB slope only. And if I use the same slope (12dB) on sub LP, then both of these meet at cut-off frquency (usually -3dB, if 12dB slope used) where phase is reversed. In that case, I'd have to change the phase of the sub to normal (reversed to underseats). And it will get asynchronised again.

[kaigoss69]

Originally Posted by makkan00

Kaigoss
HU has abilities to tune and equilise the whole system. I read a post by VP electricity where he used RTA and found that underseats were louder when fitted in reverse phase, as they complemented the sound waves of mid better in reverse phase (I guess).
I was going to try it but though to do it with stage 3 upgrade.

To my surprise, this HU has reversed the phase of underseats automatically and that has happened each time I tuned it.
I guess due to being under seats, and playing lower frquencies, sound waves from underseats (in reverse phase) are more in sync with mids and reach to listener at same time as frquencies of mids reaches.

Since sub is fed by the same channel as underseats, it is also reversed.

As my HU allows me to reverse these settings, I have done following further experiments.
Mids: normal phase
Underseats: normal phase (reversed set by HU)
sub: normal phase

There is a delay in mid bass / bass if I do that, more noticeable from the rear sub. To sum up, sound is not coherent.

I have done the same as above but with the sub in reversed phase (from the amp settings). Sounds get terrible. Tansition of sound from underseats to sub is messed up.

I read somewhere that time allignment matters upto 2Khz and after that it become meaningless due to high frequencies. I am not sure how true is that, but it clearly emphasis the importance of time / phase allignment b.w mids, underseats (mid bass) and sub bass.

Hope it answer your question.

Thanks for the info. Interesting that the auto-tune reversed the phase of the midbass/sub channel. I have played a lot with sub to midbass phase, but never with midbass to midrange. I'll have to try that!

I wish the MS-8 had the capability to make those corrections during auto-tuning and would give the user the ability to make them afterwards as well. Same with sub TA. I don't care what anyone says, you can get the sub better integrated with TA. As I have pointed out, MS-8 users are stuck with reversal of speaker lead polarity and crossover slope as the only methods for integrating the sub with the midbass, which is often not enough.

[makkan00]

Originally Posted by kaigoss69

Ha, I read right over that! I'm guessing he did not want to bring the SWS up that high. Sometimes a gap is ok or even desirable, especially when you're having phase issues at the crossover point. In this case though I'd advise Mak to bring the Focals down to 160 - 175Hz, they can do that easily with a 24dB/oct cut-off.

You have explained the answer beautifully.
I have used Focal @160Hz HP as well and in IMO they are far better if I HP@ 200Hz.

[makkan00]

Originally Posted by kaigoss69

Thanks for the info. Interesting that the auto-tune reversed the phase of the midbass/sub channel. I have played a lot with sub to midbass phase, but never with midbass to midrange. I'll have to try that!

I wish the MS-8 had the capability to make those corrections during auto-tuning and would give the user the ability to make them afterwards as well. Same with sub TA. I don't care what anyone says, you can get the sub better integrated with TA. As I have pointed out, MS-8 users are stuck with reversal of speaker lead polarity and crossover slope as the only methods for integrating the sub with the midbass, which is often not enough.

You are welcome buddy.
I remember that VP was the first person to try phase reversal b.w mids and underseats and sound was coherent and louder on RTA.

Tell me about MS-8.... I am going to tweak sound system of Rudz (with MS-8) where you have to reverse the polarity manually or on the amp (if provided).