Complete guide of speakers in the B9 B&O system

[Bobby Kinstle]

I originally posted this in the audio forum but a user suggested I post it here too. I investigated the characteristics of every driver in the B&O system as separately as I could without you know going to an anechoic chamber and then running really long wires to my car parked outside. I used a good quality microphone along with some software designed for testing speakers. I also removed most of the drivers and measured them for size, depth, hole patterns, impedance, etc, and finally tried to determine a power rating based on the stickers on the back sides of the drivers and some SWAGing

https://www.audizine.com/forum/showt...B-amp-O-system

Or here's a direct link to the spreadsheet

https://docs.google.com/spreadsheets...it?usp=sharing

I hope this data is useful for anyone looking to make some modifications to their stereo system. I'll update the sheet as I go along, but this is a side/hobby project so it may go weeks without updates if I'm just plain busy with other projects or the kids.

[Yabi]

I will admit that I was the user who recommended Bobby post a link here. His research on the B9’s audio system is unprecedented. Truly pro-level effort in his research and documentation.

[roro]

This is amazing. Thank you so much for all your work on that.
Do u have any recommendations for rattling subwoofer plastic cover? It’s driving me nuts. Most people recommend just taking the cover off or putting rubber underneath the edges, but maybe you have better insight since you’ve unboxed the drivers yourself.


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[Bobby Kinstle]

This is amazing. Thank you so much for all your work on that.
Do u have any recommendations for rattling subwoofer plastic cover? It’s driving me nuts. Most people recommend just taking the cover off or putting rubber underneath the edges, but maybe you have better insight since you’ve unboxed the drivers yourself.

Take out the rear deck, dynamat the metal shelf, and add some foam strip tape, like the kind you put around windows and doors in the places that are close to the metal. This wasn't much of a problem on mine except at very specific frequencies but it went away entirely after I swapped the sub and added dynamat.

BTW here's a guide I wrote on that other forum about how to take the rear deck all apart.

https://www.audiworld.com/forums/s4-...e-b-o-2972479/

[roro]

Take out the rear deck, dynamat the metal shelf, and add some foam strip tape, like the kind you put around windows and doors in the places that are close to the metal. This wasn't much of a problem on mine except at very specific frequencies but it went away entirely after I swapped the sub and added dynamat.

BTW here's a guide I wrote on that other forum about how to take the rear deck all apart.

https://www.audiworld.com/forums/s4-...e-b-o-2972479/

Thanks!!

[Bobby Kinstle]

I added a page to the spreadsheet called "My Car" which shows the work I've done to my own car so far.

[Bobby Kinstle]

Jorge GS from Audiworld tracked down the pinout for the 38 pin connector on the B&O Amplifier and I've added it to the guide. See the tab marked Amp wiring chart

The original thread is here:

https://www.audiworld.com/forums/s4-...trunk-2973498/

[Bobby Kinstle]

I did some measuring today with the problem of overlapping bass between the new front door woofers and the subwoofer. The door woofers now play clean down to 45Hz, Roll off at 44Hz and are almost gone at 43Hz.* SO this leaves me with a couple choices.

1. Install a 14 mH inductor on each coil of the woofer to block frequencies above 45Hz.* SOunds easy but the only parts I can find are 4.5" long x 1.5" diameter, weigh 1.5 pounds, and cost $37 each
2. Set the crossover point to 53Hz which drops the inductor price to $11 each but then requires an exotic (expensive) capacitor on the front door woofers
3. Set the crossover point to 60Hz which means I can use a commonly available capacitor on the front door woofer.

Do you think 60Hz is too high to transfer from the door woofers to the sub?* I'm afraid this will make the bass too strong if I really crank it up.

Alternatively I could buy an amp with a built in low pass filter but that's the most expensive and convoluted of all.

[Batman0424]

This is a great write up and valuable information.

One thing I noticed, the B&O system in the S4 sounds better then the system from the RS5. I believe these are the same systems, so maybes it’s the interior size, exact speaker placement, trunk size, something. But, it definitely, to me, sounds much better.


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[Burrcold]

This is a great write up and valuable information.

One thing I noticed, the B&O system in the S4 sounds better then the system from the RS5. I believe these are the same systems, so maybes it’s the interior size, exact speaker placement, trunk size, something. But, it definitely, to me, sounds much better.


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Absolutely agree. I had the B&O in both my 18 S5 and 19 S4, and the S4 sounds so much better. I have no idea why as I believe they have the same amount of speakers. Maybe because of the more rigid boxy design of the S4?

[Bobby Kinstle]

The deeper I get into this particular bass overlap problem, the more I think the solution is to put the sub on it's own amp that has a built in low pass filter that can go down to 45Hz.

[Yabi]

The deeper I get into this particular bass overlap problem, the more I think the solution is to put the sub on it's own amp that has a built in low pass filter that can go down to 45Hz.

I like this too. It seems like the right way to do it

[Bobby Kinstle]

Update:

I finished trimming the plastic behind the front door woofers so now I can put the panel back on properly. The bass response is noticeably better either because the door panel isn't touching the woofer frame anymore, or because the grille is 1/4" closer to the driver. Either way, I'm happy for it.

Ordered a sub amp today. I finally found one that can turn on with speaker level inputs and can set the low pass filter below 45Hz. Pioneer GMD8701

[jgtripleog]

Wow this is amazing work! Thank you very much for taking the time to not only do the work but also put together the report.

[Bobby Kinstle]

You're welcome. I know a lot of folks are really frustrated by the stereo. I'm the kind of person that if I don't like something, I fix it, and if it doesn't exist, I'll make one. It's my sincere hope that others find the information useful if they decide to make changes.

There's another guy over on AudiWorld that's trying to decode the optical signals and put in his own signal processor so he can define his own crossover points and amplifier channels. Even I think that's a crazy effort.

https://www.audiworld.com/forums/s4-...trunk-2973498/

[vsaudi]

I am in process of swapping out my B9 B&O and this is great info.
will share pics when I get started.
planning to hook NAVTV Zen V to MOST output then TOSlink to Mosconi DSP 8to12, then RCA to Mosconi 5/30 and 4/10

[Bobby Kinstle]

I am very interested in your work on the signal processing side. When you have it working I'd like to add it to the guide.

[Bobby Kinstle]

Has anybody mounted an amp in the trunk? If so would you mind sharing photos of the installation? I'm looking for a place for a sub amp.

[vsaudi]

Has anybody mounted an amp in the trunk? If so would you mind sharing photos of the installation? I'm looking for a place for a sub amp.

I have a b9 RS5 sport back and looking for a place to put 5 channel amp.


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[Bobby Kinstle]

I found this one from a B9 avant in the spare tire well

[vsaudi]

Thanks
I am looking at that area but amp is a mosconi 5/30 and is about 20” long.


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[vsaudi]

It actually might fit


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[Bobby Kinstle]

Do you have room to get the cable connections out? That would be a really clean installation there.

[Yabi]

Not mine, but an alternative to hiding the amp could be to showcase it...

[Bobby Kinstle]

I can showcase the amp right below my collection of child safety seats.

[Bobby Kinstle]

The amp does fit under the spare tire, but it also covers up the bolt for the battery hold down bracket which means the amp will need to be removed when I change my battery. Though in all fairness that won't be very often. Its too big to fit in the side compartment, and under the rear deck is still on the table.

As a side note when connecting your amp, don't connect the ground wire to the terminal tightening screw on the battery. Connect it to the end of the cable that is bolted to the chassis. The reason is because there is a device that disconnects the ground lead when your airbag deploys and connecting to the screw will bypass this.

[vsaudi]

Bobby
I got install done.
Had same issue with rear bolts on battery
Will post more pictures

Install is:
Nav TV Zen V (MOST input)
Mosconi 8-12 DSP Pro (TOSLINK input)
Mosconi 5/30
Mosconi 4/10
Focal KX3 3-way active fronts
Focal PS165 2-way passive rear
Focal KX25 subwoofer.

In process of tuning it.





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[Bobby Kinstle]

Bravo! Yes please post more pictures.

Mine had to go on the shelf for a while as I had to deal with my mom's estate over the past couple weeks but I hope to get the final connections made in the next week or so and then I'll have some pictures of my own.

[vsaudi]

Here are some pics
Sorry for iPhone camera.




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[Yabi]

If it sounds half as amazing as those installation pictures look - I'm sure the system kicks butt!

Well done!

[Bobby Kinstle]

Have you been able to get the front pillar tweeters to play above 10KHz?

[vsaudi]

If it sounds half as amazing as those installation pictures look - I'm sure the system kicks butt!

Well done!

Thanks
Really happy with the sound. Need to finish tuning.
Thanks to Bobby for the pictures of his system. Really helped spec adapters and depth of speakers.


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[vsaudi]

Have you been able to get the front pillar tweeters to play above 10KHz?

Yes but they are the Focal tweeters
I took out the upper pillar tweeters out of principal and installed the Focals with new wiring all the way to amp.


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[vsaudi]

Still working on speaker grill holes.
A lot of drilling and grinding.



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[BrockDM]

How hard is it to remove the door panels? I don't plan on upgrading the sound system but I've been leaning towards laying down some Dynamat to help with any rattles and road noise.

[Bobby Kinstle]

Still working on speaker grill holes.
A lot of drilling and grinding.

When I did mine, I just sanded off the back with the top curve of my belt sander. That was decently easy, just time consuming. Don't go too fast or the plastic will melt. Even then stop ever minute or so, let it cool and break off the plastic wads that bunch up. Sand some more...

[vsaudi]

How hard is it to remove the door panels? I don't plan on upgrading the sound system but I've been leaning towards laying down some Dynamat to help with any rattles and road noise.

Door panels are easy
Start in front of trim with trim lever
Remove three Torx screws
Levers around edges at bottom
Lift up
Unhook cable for door latch
Disconnect a few cables.




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[vsaudi]

When I did mine, I just sanded off the back with the top curve of my belt sander. That was decently easy, just time consuming. Don't go too fast or the plastic will melt. Even then stop ever minute or so, let it cool and break off the plastic wads that bunch up. Sand some more...

Thanks
Was melting plastic with grinder. Will try with more patience.
Drexel is too fat for gaps

I would like to fix the tweeter grills as I think they don’t look very sound conducive.



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[Bobby Kinstle]

How hard is it to remove the door panels? I don't plan on upgrading the sound system but I've been leaning towards laying down some Dynamat to help with any rattles and road noise.

It's very easy. Pop off the trim pieces, take out a few screws, pop the snaps along the bottom edge of the door, and lift up. Can be done in less than 60 seconds.

[Bobby Kinstle]

Thanks
Was melting plastic with grinder. Will try with more patience.
Drexel is too fat for gaps

I would like to fix the tweeter grills as I think they don’t look very sound conducive.

Mine look pretty ugly on the back side, but hey you can't see that. You only need to remove enough material to open the back side. Then I cleaned up the edges of each hole with a SHARP exacto knife. I probably spent 3 hours working on the pair.

Do you have pictures of the pillar tweeter installation?