Best mounting position for self powered and enclosed sub in trunk? - Page 2 - PeachParts Mercedes-Benz Forum

donbryce · #16 02-25-2004, 12:18 PM

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.

Alan Hamm · #17 02-25-2004, 12:34 PM

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?

donbryce · #18 02-25-2004, 01:15 PM

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.

JHZR2 · #19 02-25-2004, 02:18 PM

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

Alan Hamm · #20 02-25-2004, 02:33 PM

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.

JHZR2 · #21 02-25-2004, 02:50 PM

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

Alan Hamm · #22 02-25-2004, 03:01 PM

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.

donbryce · #23 02-25-2004, 03:32 PM

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.

JHZR2 · #24 02-25-2004, 04:17 PM

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

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

donbryce · #25 02-25-2004, 07:34 PM

Quote:

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?

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.

JHZR2 · #26 02-25-2004, 08:07 PM

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

donbryce · #27 02-25-2004, 08:38 PM

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?

JHZR2 · #28 02-25-2004, 09:40 PM

Quote:

Originally posted by donbryce
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!

donbryce · #29 02-26-2004, 07:33 AM

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).

Alan Hamm · #30 02-26-2004, 08:21 AM

Quote:

Originally posted by donbryce

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.

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.