Best mounting position for self powered and enclosed sub in trunk?
 

Hi,

I decided to buy a kenwood KSC-WA62RC WooX subwoofer for my 83 300D. Its a really small unit that is self-amplified, self enclosed, and has gotten a lot of good reviews.

I have heard of two possibilities: on the parcel shelf near the rear windshield or in the trunk.

-If I put in on the shelf by the rear windhsield, won't summer sun ruin it? I have to imagine its not good for this sort of stuff to be in direct sunlight (thus the relatively thick speaker grilles on the cars).

-If I put it in the trunk, what is the best way to point it? I have read that sometimes this sort of sub is best located as far forward in the trunk, with speakers pointing away from the pasenger comaprtment. I assume this is so it can vibrate the maximum volume of air in the trunk the easiest. I think this would also be the easiest for me to mount. Any comments/suggestions on how to mount it?

-Finally, wiring. I got this sub because I can attach it into the wiring for my rear speakers. However, I worry about the power wires. Apparently it needs a constant and a 'turn on' wire. I figure I can get constant somewhere in the trunk, or else run it straight from the battery, no biggie. However, how do I signal it to turn on? My original becker europa doesnt have an amp that I know of, nor an output to signal an amp to turn on. Will I have to set up some sort of a switch to give a momentary power spike to the unit to tell it to turn on? Or does the power antenna get this spike to tell it to extend/return when the radio goes on?

Any help would be great.

Thanks,

JMH

JMH,

I faced a similar dilemma after I purchased a Clarion powered sub, roughly the same size as the WooX. It would not fit under the seat of my '84 300D, so I decided to take drastic measures. I will try to post some pics, but here's what I did:

I cut a hole in the hat shelf (not for the faint of heart) the size of the sub, and a matching hole in the fabric shelf cover. I then sunk the unit about halfway down and mounted it with some custom-made hardware. The sound is pretty good, but the flimsy steel of the rear deck needed some reinforcement in order to improve bass response. I sprayed some noise killer on the surface underneath and also placed (read: crammed) lots of foam between the fuel tank and the shelf. This greatly improved the sound.

Of course, the downside to all this is that I have modified the body of my car irreversibly...but I plan to keep her awhile.

I made a simialr modification to the front doors, where I installed 6.25" MB Quarts, powered by a PPI amp in the trunk (mounted on MDF). There are 2 more amps powering more speakers, so my system sounds fairly impressive. Pictures to follow...hopefully.

Hi JMH.


When living in Europe I had a 82 VW jetta
and I mounted a simular sub to the bottom
of the parcel shelf(in the trunk).

I would power the unit directly from the battery.

I don't know if that sub comes with any wires.
If it does then make sure the inline fuse on the
power wire is as close as possible to the battery.
If you have to wire it yourself then buy an inline
fuse to protect your car,and the fuse should be
of a lower value than the one on the sub,this way
the inline one will blow first and prevent a possible
fire.

Experiment with placement until you are
satisfied with the sound,then mount it in
this position.
It will sound better in the passenger area
then in the trunk but the trunk is bigger and
offers more options.

Yes speaker don't take to well to sunlight.

To turn the unit on,you can patch in to the antenna
energizing wire,this way when you turn the radio
on(assuming that the antenna still goes up when you
turn the radio on)the amp will come on to.

Hope this helps.

Louis.

Thanks!

One more questiuon about the antenna turn-on wire... If I have the antenna switch in the full down position, does the antenna not get the energizing signal? Often when using my CD chganger, I leave the antenna down all the way. Id hate to have my sub turn off because I put the antenna down...

Would I have to wire the turn-on wire in before the antenna switch?

Thanks,

JMH

JMH.

What you could do is just get one of
those automotive relays and wire it into
the ignition so that the amp is on whenever
you start the car.

Louis.

JHZR2,

First, be prepared for the fact that if you put it in the trunk, you will not hear a thing. I installed a powered Bazooka into an '85 300D and was all thrilled until I turned it on. Nothing, nada. I walked around to the trunk and could hear a slight rattle and put my hand on the top of the trunk and felt tremendous vibration. Opened the trunk and the neighborhood could hear the bass. Those 300D trunks are practically air tight. I ended up drilling holes into the metal shelf to let sound thru. It worked to some degree.

That being said, I am in the final stage of installing an Infinity Basslink powered sub in my SDL. I agree with the comment to wait to mound the sub until after you experiment a bit. I have checked and the trunk of the SDL is no where near as tight as the 300D (at least visually) but I will soon find out as I connect wires tonight.

What I am thinking is that I will rig this with quick connectors so I can mount on the floor in the rear seat during the 90% of the time there are less than 4 people in the car. With quick disconnects, I can quickly remove and relocate the unit to the trunk for trips with a full car.

Of course, if I hook it up tonight and it works and sounds great in the trunk, it will stay.

As for the remote turn-on, I do not think the antenna lead will work unless you keep the antenna up. I am sure this is why the newer units have a seperate lead. However, the Infinity unit I have says that if you use the direct speaker connections instead of the pre-amp RCA feed to the sub, this is enough voltage and you do not need a remote lead.

I am also fairly certain you will need to run a large positive lead direcly to you battery (fused of course). Depending on the power of your amp, this wire might need to be quite substantial.



Curious about the Kenwood unit.

As promised, pics of my system:

And another:

Last one:

Hi Matt.

Very nice system.

One thing to remember is that some people
don't like cutting into trim and metal panels,
me included.

For the front speakers custom kickpanel can
be made from the original kickpanels and
keep the OE's,for when you sell the car.

For the subwoofer you can use the first
aid kit space as a vent or even as a mount
for a subwoofer and hang the enclosure
from the parcel shelf.


If you need to cut up or into a panel,a fiberglass
copy can be made and wrapped in a fabric of your
choice/to match.
Thus preserving the original panel.

Enjoy your system.

Louis.

Well, the experiment is somewhat a failure. It appears that the Infinity has far less "uumph" than the Bazooka in my 300D. I can barely hear a thing with this in my trunk. I have tried several positions and it makes not much difference.

I am back to the idea of quick disconnects so I can mount this in floor at the rear sear but quickly move to the trunk when I have guests.

Damn Mercedes are too well built!

Very interesting... This fellow had great success with hix kenwood woox (same subwoofer I got, 5 1/2 powered, 6 1/2 passive radiator, self amplified and enclosed) in the trunk of his 85 380SE, mounted sideways:

http://www.peachparts.com/shopforum/car-audio-multimedia/68283-mounting-idea-kenwood-powered-sub-woofer-380se.html

JMH

But personally, Im liking the idea of sticking my sub, which has a really small footprint in the cutout for the armrest (kind of into the seatback when the armrest is down). Sure the armrest would be down all the time, but so long as the sub facing forward in the cabin won't be too overpowering for front or backseat passengers, all is well. AND, I can take 4 passengers anytime.

JMH

I don't get it. I have a remote gain switch on mine and when I adjust I cannot tell any difference.

HOWEVER, I just realized that I had not told the head unit that I now have a sub. I just this am found an online users manual to figure out how. This might make a huge difference. I will let you know.

Duh, SMACK!.....Duh, SMACK!........
 

Well guess what, turning on the subwoofer in the head unit makes quite a difference ! Duh, SMACK!

It is not thumping bass like many people like, but it is there. Now I need to tune it properly and enjoy. I will still play with positions before a final mounting, but the option to move into the cabin is on hold for now.

Hi JHZR2. I'm the guy with the WOOX mounted sideways in the trunk. I see that the picture in the post (link provided above) showing the unit mounted has disappeared. But the 2 bracket pictures I added later are at the end of the thread.
Anyway, 2 things for you to consider:
1. I get lots of bass with no holes cut in the package shelf. It's not necessary, so hook it up first and try it. The 2 plastic trays and thin shelf masonite don't block much of the low frequency bass waves to matter.
2. The WOOX can be driven from the speaker leads going to your rear shelf speakers (line input), or from an RCA output on the head unit (low-level or sub-out). I just spliced mine into the wires going to the speakers on the rear shelf in the trunk.
As far as power, you can run that off the power antenna lead, or any switched (ign) 12V source. Since I always have the radio on, and usually listen to FM, my antenna and WOOX effectively get 12V anytime the car is running.

Donbryce,

When you say power, are you referring to the main power for the amp or just the remote turn-on? If I recall, the Kenwood has a 50 watt amp so I am just curious if the antenna power is enough.

Also, if you play a tape or cd, does the sub cut off?

The way I set this up may not work for you, since I thought I read where you turn the antenna switch off to keep it down when using the CD player. I don't use that switch. It's designed to bump the antenna up or down to optimize the mast length for reception. Great idea in 1985, but not very useful for today's receivers.
But on the subject...The Kenwood will run just fine off the 12V supplying motor current to the antenna. It draws 12A at maximum current, and comes with an in-line fuse anyway. The 'trigger' wire for an antenna is designed to provide 12V constant (but very low amps) to put and keep the mast up. Removing this voltage (as when the antenna sw is off, or in a conventional set-up, when the radio is turned off or power to it removed) reverses the motor direction and the constant 12V source powers it down.
To sum up, you can use the main antenna power wire for your Kenwood safely. If you want to have the unit powered up whenever you run the car, irrespective of the antenna, you'll need to connect the trigger wire (PCont) to a switched (ignition) source.
I can't remember what's in the antenna harness, but you should be able to find an ignition switched 12V wire that will see 12V regardless of the antenna switch position....assuming that you want to retain the ability to have the mast down when playing CD's. IMO, having the antenna down while driving serves no useful purpose, as long as it goes down when I turn the car off, mainly to discourage vandals.

I have the woox, and am preparing to install it. Mounting position is unknown, but as I said, either in between the two rear seats (the armrest cutout in the seatback, or most likely and preferably the trunk, by where my CD changer is mounted (hanging down), because it is wasted space anyhow most of the time.

The unit's power cords are as follows:

-14AWG main power line (yellow) with 15A fuse inline - connects to two 18 AWG short power jumpers so that the power line can be integrated with the small wires in the harness that attaches to the unit itself.

-18AWG on/off line (blue)

After figuring out my plan and talking with crutchfield, I have decided the following:

-I will run 12AWG wire from the positive terminal on the battery, through the firewall, but the driver's feet.
-Under the kickpanel, I wull use a crimp connector to attach the 12 AWG wire to the (yellow) 14 AWG power wire that goes to the unit, AND the 18 AWG (blue) on/off line that also goes to the unit.
-On the 18 AWG on/off wire, ill put an inline fuse (It is supposed to be attached to fused accessory power, and since my 12AWG line is coming straight from the battery, ill put a 7.5A fuse in there to serve the same purpose)
-In this on/off line Ill have an illuminated on/off switch ($6, available at truckstops). This way ill have ultimate control over whether the amp is on or off, no matter what configuration i'm using.

Ill wire the unit right into the rear speakers, and be good to go. Ive read in many places that the w123 trunk is tighter than the w126 trunk, so Ill have to see about placement for bass to get through. but Im hoping the trunk will be the best place. I think that the armrest in the seatback will make the sound stage too far forward and be too boomy for everyone. On the hump in the floor between the two rear footwells would probably be the same, but at least it would first radiate up instead of at people and the front windshield.

donbryce: What did you do with regards to the speaker wiring connections? Thge wiring on the kenwood is all male/female pin type (round) connectors, and I am guessing, but most likely the speakers are spade connections... I think the connectors on the kenwood wiring look to be of great quality, so Im going to sut into my speaker wiring (leaving the connections to the actual speakers in place), and attach male/female pin connectors as needed. Is this what you did, or how did you deal with the speaker wire connections, as Ill bet they are the most important part ofthe setup, since they can really effect sound quality.

Thanks!

JMH

Remember, you can also control the sub's bass level. With a 123, I really think you will have trunk issues. You could remove the first aid kit. but even with an 8" or 10" bazooka, I had trouble getting any bass in my 300D.

Im a little worried about manipulating the sub's bass level much. i think the lower (with nice clear audible bass response) level the better. If I have to put it high (in order to get through the trunk, for example), i fear there will be too much vibration and not enough good sound.

Im just going to play it by ear... I think Ill probably start out seeing if there is a suitable spot int he cabin. this way I won't even have to worry about issues in the trunk, and if it fits in one of the spots Ive said, then all is well. Plus, this way i only have to run a ground wire into the trunk (antenna groundin point looks best/easiest), rather than all the speaker and other wires into there.

I need to get my car back from the shop tomorrow so I can start experimenting... This is exciting!

JMH

Yea, I hope it does what you want. I am still playing with mine now that I have it turned on. I am hoping to have it right soon. I did install a remote adjustment for my Infinity that I think will be useful. There are just far too many things to tweak.

Well, no offence to either you or Crutchfield, but the 12 guage power wire from the battery is really not needed for this unit. As I said, and this is from the KSC-WA62RC service manual, it'll draw 12amps max on a 15amp fuse, and seems like a lot of work for nothing if you are going to trunk mount it. Your choice, though. I've had no problems at all running mine off the antenna power wire.


For the speaker connections, I just bared about 1/2" of each of the 4 rear speaker leads (without cutting them) and spliced the req'd lengths to connectors to plug into the 4 input leads on the plug harness. I also soldered and taped each connection.

Thanks for the info... I like the idea of having a beefier wire going in from the battery, because Im supplying power to other stuff as well (CB, extra power outlet, etc) and I want to put it all on one wire instead of having two wires at the batery terminal (instead of one for thesub, one for the rest of the extras)... Plus I like to overdo things a bit :cool:

Just to get it straight... youre saying that the main power line at the antenna can be used regardless of if the antenna is up normally, max, or off and down completely? I ask this becuase you said that with radio off, or switch is down, there is constant 12V to keep the antenna motor in the down position. This means that the trigger that upplies voltage to move the antenna up or down is seperate from the power source that actually moves the motor. Do I have it right? If so, I'll just use that and use the currently in place wire that I'm using to power my CB.

Also, I have to assume that that if there is 12V to move the motor, then also a trigger input as well, that the 12V isnt really constant, but rather it is switched with the accessory key, since it is part of the radio system. That said, couldnt I wire the on/off into the same constant 12V and then have power to the sub only when the accessory position or better is chosen, rather than having to put hte blue on/off wire into something else??

I wont be blasting the subwoofer anyway... So I doubt Ill be pulling full power anyhow.

thanks for your help,

JMH

Partly. The wire that supplies constant 12V is separate from the 'trigger' 12V wire, but it doesn't "keep the antenna motor in the down position". I didn't say that. When you turn on the radio, 12V is applied to the trigger wire, which connects the constant 12V to the motor. Turn the radio off, 12V is removed from the trigger, the motor is powered in reverse from the same constant 12V wire. How the motor turns off at the end of the mast's travel, up or down, is another subject.

In the Kenwood, the 12V fused input doesn't connect internally until the blue wire sees 12V. Take away the 12V, and you disconnect the power to the unit, internally. It doesn't matter that the 12V yellow is direct off the battery or switched from ignition, except that if it were switched, and ignition off, applying 12V to the blue wire wouldn't turn the unit on.

So, you have an ignition-switched 12V source already for the antenna, the CB, and the CD changer, any of which could probably serve as the switched 'constant' source for the fused lead. I guess the issue is how to switch the current to the blue wire, to get it to turn on and off with the radio or the CD player.

OK, thanks very much, makes plenty of sense to me now...

besides the CB and power outlet, which was very simple and straightforward, ive never really messed with wiring things up before, particularly not audio stuff. But I think Im going to try it your way and I'm sure itll work out nicely.

I have the radio on 95% of the time Im in the car... But do you think having the sub powered without the radio on/in use will be bad for it (I think Ill attach the blue and yellow wires together, so whenever there is accessory power for the antenna, the sub will also be on, and I dont have to worry about switches or anything else).

Thanks again,

JMH

Alan: I'm glad you got your Basslink fired up nicely. I have one of those too, mounted in the trunk of my streetrod, complete with remote gain control. I actually never found the remote all that effective, unless the gain on the unit was turned up. And, like your experience, I had to configure the HU (Pioneer) to output properly to the sub. The rod also has an MTX 250W amp and 2 10" subs working with the Basslink. I had quite a few interesting discussions on the car audio forum about this setup!

As to a comparison, the Basslink is much more beefy than the Kenwood, but it depends on the mounting and the degree of isolation of the trunk from the cabin. It's also quite a bit larger. I've not had any experience with the Clarion unit, nicely mounted by Zoonhollis, and that appears to be about it for self-powered compact subs out there. I tried a 'tube' unit, but they don't have the internals of any of these, and are too big for my taste.

I think if the Kenwood is hung right under the package shelf, facing down, it should sound just fine.

JHZR2: I was thinking that too, just wiring the blue and yellow to an ignition switched source. Just be sure it is switched, though, or the unit will be on all the time and would likely drain the battery. It wouldn't matter a hoot that the radio (and CD player too for that matter) were off while the unit was on. That'd be like turning on the CD player and not putting in a CD.

Let us know how you made out. I'm curious about the original radio and the trunk CD changer. Are these completely separate, so you put CD's in the trunk unit and control it with a remote?

Its a JVC RF modulated CD Changer- 12 disc unit. hangs off the ceiling of the inner trunk, kind of under the rear parcel shelf. It just has one wire going through the cabin under the floor, its a thin wire thats enough to provide power, all the outputs, etc. Feeds to the power connector and RF modulator, which sits behind my becker europa in the dash.

Despite only running on RF modulation of FM audio, the sound is actually quite good. Depending upon the type of music, you can often tell when using burned CDs from MP3 files. But its not bad, sounds like typical FM radio. Using professional original storebought CDs, the sound is really clean and clear, despite being the original 21 year old components and an FM CD player. Great investment for $150 or so.

JMH

P.S. The constant 12V at the antenna, which you used for power... Isnt that switched when you put the key to the accessory or on positions? I cant imagine that there is always 12V to put the antenna up/down, even when the radio cant possibly turn on... Where did you connect the blue wire, to your headunit? Thanks!

Yes, the 12V wire is switched by ignition. Sorry I can't recall the color code for the wire, but it probably wouldn't match yours anyway. As such, it is fused at the fusebox, so the in line fuse on the WOOX yellow wire is probably redundant (but safe) .
And yes, the blue turn on wire is connected to the head unit's antenna trigger wire (Blaupunkt Denver).
As an aside, I'm using the original Hirschmann antenna unit, but the electronics have been replaced with those from an aftermarket antenna, and thus uses the more common 3 wire set-up (12V power, 12V trigger, ground) (that's another reason why my dash antenna switch isn't used).

Don't forget Bazookas. I have an older one in my 300D. If I had to guess, I would say the bazooka has more "thump" than my Infinity. But I am still tweaking. There are so many possible settings on the had unit alone that I have not gotten through those yet. I have easy gain control on the head unit , plus the remote. I do notice a difference on the remote at the high end, when the head unit gain is pretty high. Biggest reason for it is those super bass (ie) songs where you start to get a little distortion, you can lower the level quickly using the remote.

This is fun.

Now I see you said you tried "tube"units. Not sure what you mean by not having the internals. My bazooka has a built in amp, but I forget how powerful.

Hi. What I was getting at is the relative size of the bazooka tube and its output, compared to the size of the Basslink or Kenwood. I tried a unit with, I think, 8" speakers, and wasn't impressed compared to the Kenwood. If you go up to a tube with 10" speakers (they have 1 active and 1 passive, right?) the sound improves, but the size gets bigger too. As to power, the Koss MSP8200 has '200W maximum' power, which might be 50W rms, who knows, but takes up the space of 3 Kenwoods. Let's not get into discussing sub enclosure design here, though. I'm just pointing out the space-to-bass merits of these compact units.

No, I do not want to debate the merits of the designs either. I actually stayed away from the bazooka because of the size. Only reason I installed one in my 300D was because it came in another car and I hated it there.

Seriously, how does the Kenwood compare with the Infinity in terms of output? They are comparibly priced.

Difficult for me to provide hard data there, because my Basslink is running along with 2 10" MTX subs and a 250W MTX amp, in a different car. Also, the power output of the Kenwood is stated at 50W/2ohms+50W/2ohms Maximum (dual voice coil drive), the Basslink is 200W RMS. So, based on the rated power output, the speaker sizes, and my subjective ear response, I'd say the Basslink is the winner of the SPL level competition, but the Kenwood gets the nod for the most sound out of the smallest 'box'. We're comparing the Kenwood with a 5 1/4" active woofer and a 6 1/2" passive radiator, to the Basslink's 10" driver and 10" passive radiator.

The Kenwood just intrigures me, if it works in that it uses less power, is smaller and could be in the cabin, perhaps under a seat. That unit, in the cabin might be better than the Basslink in a trunk.

Why a Basslink together with the other subs? It seems to me it would be dwarfed. Don't want to beat this subject to death though. Just curious.

I was off reading about the best placement for subs in a car, and the opinion of most is in the trunk, not in the 'cabin', but I haven't been able to find a clear explanation of why. I did try the Kenwood sitting on the package shelf, and it wasn't 1/2 as good as in the trunk. I think it's because the sound waves cancel each other out when the unit is in the same enclosed space as the listener.

Here's a link to a good study of mounting options in the trunk http://www.installer.com/tech/aiming.html

Well, on the idea of combining the Infinity with the 2 MTX's, it's still an experiment. I've had lots of back and forth with the car audiophile crowd on this. My theory is that if all three cones are moving together, as in 'in phase', I'll get more SPL since I'm moving more air. Combined, I'm running 450W RMS, no big deal really, with 3 10" active speakers and 1 passive radiator. All technobabble aside, it just sounds better, with more punch, with the Basslink than without.

Here's a link to my rod site, go to the sound system pages:
http://bryceandbernie.homestead.com/BrycesRodWebpage.html

Great links. Great job on the street rod. I tip my hat to you. Would love to have the time and skill to do that someday.

JHZR2 - Did you get the car back today, and how goes the install?

I would suspect that the reason for all the suggestions of putting the sub in the trunk is because low end frequencies are non-directional.

Don.

Cancellation only happens when the soundwaves
bounce back off of a surface and interfere
with the ones coming from the subwoofer.

Also an enclosure works best when securely
mounted to a solid surface(floor of the trunk)
This transfers the bass to the entire vehicle.

In some cases like the Bazooka it needs to
be corner loaded to achieve the best result.

Bass is like the ripples in a lake after you
chuck a pebble in it.
The ripples go in all directions.
Unlike a tweeter,which sound patern is narrow
and focused in a small area,like a flash light.
That is why you can mount a subwoofer in the
trunk and still hear/feel it inside the cabin.
The trunk usually amplifies the compressing
of the air(a subwoofer is basicly an airpump)
but sometimes some experimenting has to
be done to find the best mounting position.

It is a common misconception that bass is
only heard,it is also felt and creates richer
music.

In your case Don the rear glass most likely
caused the cancellation.
Or even the placement.

Louis.

Thanks for the really well worded explanation Louis. I think it would be ideal to put the sub inside the cabin, but only if it is mounted properly to minimize cancellation by reflected waves, or absorbtion by upholstery. So, since this is usually impractical, they end up in the trunk, with as large an opening into the cabin as needed to let soundwaves through directly.

Got the car back this evening... Will attempt to begin install tomorrow. I'm going to scout out mounting positions in the trunk and in the cabin, then start wiring it all up.

JMH

Install complete
 

Finished the installation!

Started by wiring the speakers up. I was originally intending to leave the sub in the trunk, so I had full cabin space. But alas, as everyone has said, bass just doesnt get through the w123 trunk.
I wired the on/off to the antenna switch, and the power to the antenna constant, and tried turning it on and off at various situations, speeds, types of music. Besides on very bass heavy music, with the car off or at idle, there was no notiucable difference, and even in those situations, it was hard to tell if it was actually noticable or if it was my imagination.

So I decided to put it in the left rear footwell. I figure its sitting on the carpeting, and it wont really go anywhere, so I dont even have to drill holes. I left enough slack so that I could sit it in the middle of the rear seat if I had 4 passengers, or even pull it up on the rear parcel shelf if needs be

I decided that instead of stripping the antenna harness, I just attached the power right up to the battery. For the switched power, I got a $6 illuminated switch and wired it into the system from the wire I have for my CB and spare power outlet. Ground does go to the antenna grounding screw in the trunk, as that seemed the closest/most convenient.

All the wires hide nicely under the seats/carpets, and the sound from the rear footwell is really good. The kenwood unit puts out just enough bass to make a noticable improvement to the music, but it isnt sloppy or unclear. Its a great unit, wouldnt need it any bigger.

So Im happy. So long as I dont get any shorts or electrical problems.

Thanks for all the help!

JMH

where to put a sub
 

i faced a simular situation, I had a all plexi glass sub with a kicker solobaric and it slid around in the trunk so i took it out and had a custom trunk done with two rockford fosgate 12's fireing back, the rest of the trunk was all did so that the amps are sunk (above the tire, a rockford 800.2 and 400.4) and the sides were done, left side houses the clarion cd changer, right side houses the rockford digital cap and behind a pannel that pops off is a hidden vcr. to the guy that says you can't hear it, it is true with the benz trunk they are harder, perhaps you need more amp or speaker or both. mine pounds my ears off. i can find the pics and upload them if you'd like? good luck

Still playing with location
 

Turns out the Infinity is capable of very good bass and the trunk of a Mercedes 126 seems to be far less air tight than a 123. I drove a lot this weekend and did a lot of tweaking to the point where I was able to achieve too much bass. I know some people believe there is no such thing as "too much", but I am simple after good clean bass which makes up for the rather smallish speakers that one can fit in the rear deck without major modifications.

Adjustments to the head unit are one of the keys. It helps to have a newer style head unit that understands subs and has adjustments to compensate for them.

I'm curious about why the trunk of a W123 is so much 'tighter' than the W126. On my '85 380SE, if you lifted out the plastic tray for the first aid kit, and'or the storage tray, you'd be looking right at the top of the gas tank. There doesn't seem to be anything except the carpeted panel in front of the tank separating the trunk from the interior. And since the plastic of the trays is thin, and the panel in front of the tank isn't anywhere near air tight, maybe that's why my Kenwood sounds fine from the trunk.
Does the W123 have a steel panel under the tray, separating the trunk/tank?

Yes,

I pulled the first aid kit, which has a thick foam gasket to keep a seal around the edges. Right below you can see into the trunk, and see the top of the fuel tank. But everywhere else, there is a metal shelf below the parcel deck. Evben the rear speakers have only a small hole at the bottom of the metal shelf to allow wires to pass through from the opening between the tank and the metal layer. To keep a tightness between the metal layer and the board parcel deck, there are tight fitting thick plastic cylinders, whichj I think help the speakers to send the sound out into the cabin, and also keep that tightness.

Driver's rear footwell is great. I keep my seat almost all the way back so I have a little bit more flexibility for stretching my legs on long drives. So that footwell is nearly nonexistant anyway. I rarely have more than 2 passengers in my car, and the sub is easily moved. Best of all, it is really stable and fits well in the footwell, without even needing to mount it. I am very happy.

My headunit (which I totally plan to keep) is proving to be the weakpoint, I think. It sounds really great and clear without the sub, but with the sub on, I have to change the sub settings a lot for various types of music. For people talking, it can get a bit too boomy. Fortunately, the bass ios very clean and clear, so its not annoying. It just seems to require a bit more tweaking than the fully custom setup in my GF's integra.

Seems like halfway on the level, and 80 or 120 Hz is the best setup for most everything... Sub on for music, off for talk. I dont quite understand the need for changing the phase yet, and havent decided what sounds best to my ear, but 0° seems best so far.

JMH

On my 123, I actually emptied the First aid kit and mounted my cd changer so it is accessed by opening the lid at the rear deck. Now that I think about it, that was pretty cool. I kinda forgot because my son drives that car now.

But basically the changer is in the trunk, vertically mounted but the front pokes up through the bottom of the first aid drawer. Then I sealed around the penetration.

I then had to actually drill 5/8" holes (about 30) into the deck from the underside to let the sound through into the cabin. I was carefull not to penetrate the carpet. This worked. Before this you could hear almost nothing. After holes, much better but not perfect.

My 126 you can hear fine without modification, but you can see that it is far less tight than the 123. You can actually see light through the storage and first aid trays.

I was actually thinking of trying that... The space between the metal layer and the cardboard parcel deck is not airtight. But the parcel deck seems to make a nearly airtight barrier. I was considering putting holes and either re-carpeting that whole thing (the blue is starting to fade a bit), or just drilling lots of small holes.

I took the lazy route though, and am happy with the footwell instalation. It gives me the ultimate in flexibility for cabin mounting, as I can stick it anywhere in the cabin and get great sound now. The trunk would probably be very slightly preferable to me at this point but not worth the effort for me, IMO.

JMH

With what I have seen of the Kenwood, I think the interior makes sense. Believe me, I was prepared to move mine inside until I figured out all the controls.