v12

This is a straight copy from a UK car audio forum i'm on.
Perhaps someone here will benefit from this.

The standard audio in the s class is better than most cars but still far from any good. The weakest point is the complete lack of any sort of bass.
Having turned into an IB junkie over the past 8 years, i've just picked up a few Haxo LXU10's to fit in.
The s class has 10" Nokia sub mounted in the rear shelf already. I want to build a decent baffle and replace that directly with a LXU.
Since i could pick up more than 1 sub I got wondering where else i could mount one.
For some stupid reason i completely forgot about the ski hatch until i went to have a measure up.
Anyway, ski hatch is 230mm tall x 240mm wide and is sloping so depth is 350mm at the bottom and 270mm at top...PERFECT for fitting another LXU in.

First question in this build is...will the 2 subs facing different directions cause me any grief?

Will be getting 500w RMS between the pair and i'm more worried about accuracy than output.
Using an Audiocontrol LC6i to convert the factory high signal for now.

My last few IB builds have been twin subs mounted on a beefy baffle on the rear shelf but i've always had to cut a certain amount of metal. I can't bring myself to cut this car!

Some pictures of how it looks :







Couple more just for fun...

v12

Went down to the breakers today to get some pieces so i can start on the baffles. Here's some pictures of all 4 mids, tweeters and the sub.
Read on the MB forum that the rear shelf is impossible to remove, guess none of them flipped the little black clips...what a doddle.









All of the speakers are bizarely pointing downwards?


Here's the boot carpet i got that may come in handy for some trimming


Some general pictures of the stripped out area








This car unfortunately didn't have the ski hatch so had a full metal tank behind the rear seats instead like most of the s-class's on the road.




Let me know if you have any other thoughts/ideas i should consider.

v12

Some of the gear which i had previously, the subs arrived today:

Audiocontrol LC6i


A/D/S speaker selection


Stitched Cone


Haxo LXU10" Underhung Motor Design
Formally known as the Crystal Comp 10




One spare, we'll see if i need 2 or if 1 will be adequate?

jbondox

build a sealed enclosure and port through the opening up top... or suspend from the top of the rear deck, and still port through rear deck... I did a few of those back in the day, and a maybach which is similar

v12

sealed
for
- easier to get right
- increased power handling before hitting xmax
- more output because of the above

against
- frequency response isn't as smooth
- extension isn't as low
- will need a bigger amp to supply more power
- more trunk space used

IB
for
- better extension
- better response
- less power needed
- less trunk space required

against
- difficult to get it sealed completely
- less output before hitting xmax

v12

Ran into a hiccup this weekend.
Stripped the boot trim to reveal the ski hatch setup.
It's not going to be possible to mount a sub there without removing the fuel tank then lots of fibreglass/expanding foam/body filler or i could mount the sub from the cabin side of the ski hatch but then i would need to cut the rear seat.

Neither option seems appealing.

I'm going to fit the rear shelf sub and see how it sounds with just the one.
Have picked up the MDF to start some cutting tonight.

grane

Consider a slot loaded enclosure.

v12

is that just a ported enclosure with a rectangular port?

v12

Stripped







Sub Amp



Quickly thrown in for testing, sub location will affect amp position so playing with the sub first to see what i like the sound of.



Quick bodge up underneath to keep things tidy.



Alu panel removed and 32mm MDF baffle made



Sub fitted



Then i got sidetracked fitting LED sidelights





One comparison shot for fun



And the sound...rubbish to be honest.
Have loads of holes to seal off still, i suspect these to be the problem as certain frequencies hit really well but on normal listening it just blends in and you have to give the sub a lot of juice to get it going.

bfisher

Ugh, hate when that happens. Appears you have the right foundation in place though to build it up into something good. I've been watching yours for my w211 (I know, not the same, but similar enough in many aspects).

jbondox

with an awesome front stage down to 50hz (most of mine) the sub is just the last part of it to round it out. sealed always seems the best for me, though my components are the Hertz Mille gear. single 10" sounds like 2 10's and is a .5 enclosure then drop the woofer in.

never had any complaints

v12

jbondox, i agree with you, in a stationary car your theory is a good one. Add road noise and you quickly need to dial the sub 60-70hz frequencies up a few db's!
Have you tried IB before?

bfisher, my dad has a 211, it certainly is very similar in regards to the audio setup!

Today's Update.
On the back of the baffle i have used some carpet underlay which seals between the baffle and the 9" square tube that goes through to the cabin side of the ski hatch.

I experimented today with it a little.

Test 1 - Rear shelf sealed with a make shift mdf plate with underlay on and arm rest down with the sub rear firing into the cabin, adjusted phase on the A6 and it sounded OK at best. Adjusted the gain a little and tried a variety of music to get a solid picture in my mind of what it sounded like.

Test 2 - Removed plate from rear shelf to allow venting into cabin. Sealed off ski hatch at cabin side with mdf plate and closed up factory hatch and arm rest to give a pretty decent seal. Measurements come up as just about 0.52cuft, within crystals recommended specs.
Had to flip the phase again and up the gain but overall the sound is much better. Louder, 'cleaner', drops just as low. Perhaps this sub really hates IB like everyone told me from the start?!

Going to knock up a 0.5cuft sealed box tomorrow and experiment with positioning, maybe just bolted straight to the rear shelf.

v12

Managed to get hold of a space saver spare which is half the width of my full size spare accommodating the amp nicely.



Sub sounded best in a sealed box shooting through the ski hatch. I propped it up on a stack of 2 x4 for testing but needed something a little more solid and removable if needed for kiddie things.

This is what i've come up with for now.



And in place





From the cabin



The fixings I added for the straps





Need some black ratchet straps now.

On music listening it's very punchy, very musical and fills in the bottom end ok but has limited extension. I fear the standard amp may have a high frequency sub sonic filter. I have the sub low passed at 50hz with no sub sonic filter and it misses notes that i was used to on my last system. It may be that i'm comparing 2 x 12s in IB to 1 x 10 in sealed though.

When i get a chance i'll get my db meter and play a couple of test tones through my ipod straight into the amp and then through the factory stereo and see if i can determine anything. Really i need to book it in to be RTAd.

v12

Well, it's been a few months of listening and using the car and 2 things happened.
- Wife got fed up of the box taking up valuable trunk/boot space.
- I missed an authorative range down to 20hz.

The 0.5cuft box ended up behind the drivers seat on the floor and i built a copy of it for the other side. Ran it for a few weeks with a sub each side behind the front seats.
The drivers side one stayed in the whole time (little one doesn't need leg room), the passenger one had to be removed a couple of times for passengers. Either way, it sounded nice, but i guess i'm a bass head at heart and i wasn't satisfied. It had output and was nice and tight, but just didn't extend like IB.

So I went back to the original plan and got some carpet underlay and gaffa tape out...Sealed every hole everywhere to the cabin and knocked up a 36mm baffle to the shape of the contours on the alu panel.

Have had it in 1 week now and it is mental...effortlessly shakes the car and reinforces those all important ultra low notes. It far outdoes the 2x sealed combo it terms of extension.
SQ wise, hard to tell them apart for me, the sealed was marginally tighter i think?
Raw output - 2x sealed was better at high volumes but IB has great output even at low listening levels.

Very happy here. I'll shut up and show some pics of what i'm living with and once i'm really happy i'll get the original carpets fitted back in and looking nice







Am i tempted to put the other sub in the rear shelf still?...yes, do i need it?...no.

v12

After months of listening and tweaking and with all the holes sealed and the carpets back in...it sounds awesome.
The bass end of things is exactly where i want it to be.
Now just need to get the 2nd amp sorted out and the door speaker pods made up.

Just need a little cover made up to protect the sub and keep it looking standard.






Sealed that top hole with multiple layers of underlay, then a mdf plate and then the carpet which you can see.