2005 W203 Subwoofer

[John]

I have a "REM" connector on the amp which goes to the blue "Remote" on the back of the head unit (blue wire)
What is "LPF"?
I've read the amp instructions about setting the "gain" but not really sure what it means - I'll plug it all in and see how it sounds!
Can I do any damage to anything??

Low Pass Filter.

Allows the low frequencies through but cuts the higher ones.

So it starts from 150Hz and goes down but I personally don't like my subwoofer doing 150Hz as I feel it is too high.

Gain is literally that. An amplifier amplifies the signal from source to output. Adjusting a gain control is increasing that amplification. Think of it along the lines of a volume control.

One way of "tuning" a system is to play music through it all with the gain at zero and the LPF at highest (so 150Hz), then raise the gain until the sound meets the same volume as the rest of the system and then adjust the LPF until it sounds like the rest of the speaker are doing what they should and the sub is doing the lower order that you can't hear from the other speakers.

There are other ways but this is normally the way I do it.

That's why having a control is useful as you will mostly hear the music from the driver seat and that's where you want to be making the adjustments.

You can't really damage anything unless you wire up something wrong spectacularly or drive the volume up too loud.

I'd always triple check what you have wired to where to ensure you did it right though.

 

[Bemmy]

OK, everything is in at last (except the gain controller) but I have no sound out of the sub. The amp is turning on and off as it should and I can hear the fan running so I guess that is working. I'm sure everything is plugged in correctly but I suppose it's pull everything out and triple check all the connections.
Is there anyway of testing the sub?

 

[John]

OK, everything is in at last (except the gain controller) but I have no sound out of the sub. The amp is turning on and off as it should and I can hear the fan running so I guess that is working. I'm sure everything is plugged in correctly but I suppose it's pull everything out and triple check all the connections.
Is there anyway of testing the sub?

Not a great start is it...

What are the specifications for the amp you bought (namely the impedance capabilities)?

On the back of that subwoofer, it has 4 / 4 Ohm, which means a 2 Ohm load bridged (which is how you have wired it i.e. in parallel).

Maybe amps at the lower end of the spectrum can't handle 2 Ohms-bridged so I wonder if there is a problem there.

Impedance (measured in Ohms) is the "load" of the subwoofer i.e. the load the amp needs to be able to drive.

We wired in parallel because you want the speaker to be loud enough but if the amp cannot drive a 2 Ohm-bridged load, it won't work.

We can't easily tell how it was wired in the first place as the 4 wires just run off back to the amp - and I would presume parallel from that but don't know for sure.

In a nutshell, the higher the impedance, the easier something is to drive but the quieter it is.

So you could try wiring it in series as the load would then be 8 Ohm.

To wire it in series, you wire amp+ to sub+, sub- to the other sub+, sub- to amp-.

Before you do any of that though, do you have a speaker you could wire the outputs of the amp to to test it is working (even a speaker from a house stereo)?

You can use any old speaker (not tweeter unless it has a capacitor / HPF on it) to test it - just loud enough so you hear a sound.

It could be the sub is knackered if you've never known it working - and in all honesty, just looking at it it's not great anyway!

One thing you can do, with it off, is gently use multiple fingers all around the cone and push the speaker down to hear if it is "smooth" or whether is "crunches".

If it crunches, the voice coil is probably burnt out.

I would never assume anything is working until you have tested it as you can waste a lot of time with assumptions. Ask me how I know that...

 

[Bemmy]

I know what you mean with the crunching - this is what started it all off! The rear passenger door speaker went "fuzzy" intermittently gradually getting worse so I swapped that out (and the driver side rear) for some small Alpine speakers which work perfectly but I lost some bass. The duff speaker does crunch when you flex the cone. I've done the flex test on the sub and cant hear anything rubbing or crunching.

The Amp is a Fly Underground 360 watt with the following spec:
Class: AB.
4 Ohm Stereo: 2 x 70 Watts RMS.
2 Ohm Stereo: 2 x 90 Watts RMS.
4 Ohm Mono : 1 x 180 Watts RMS.

Ive got the good rear door speaker still so I'll see if I get any noise out of it when I've got 5 minutes I'll also get the head unit out and make sure everything is still connected up behind that

 

[John]

4 Ohm Stereo: 2 x 70 Watts RMS.
2 Ohm Stereo: 2 x 90 Watts RMS.
4 Ohm Mono : 1 x 180 Watts RMS.

Hmm, that confirms my suspicions then.

It can only do 4 Ohm bridged!

It's not what I would call a strong amp but it should be more than adequate to drive a single 8" DVC woofer acting as a subwoofer!

So try your good door speaker with the setup as you have it now as that will either be 4 Ohm or 6 Ohm I would think and it should work.

If it does, re-wire the sub in series as per my last post and it will work, assuming the sub actually works.

No crunching is a good start!

I would hang on to your old "good" door speaker for future use too.

I have a little speaker I use for testing stuff like that not that I use it a huge amount these days.

Comes in handy though if you intend to dabble again!

 

[Bemmy]

Your advice and knowledge is invaluable! As soon as the weather lightens up I'll give it a go - will keep you posted

 

[Bemmy]

4 ohm door speaker wired to amp and it works so I know everything up to the Sub is working - back of the car out now to get to the sub to re-wire it

 

[Bemmy]

Right, Sub out and wired as above, everything put back in and working.....sort of!

I can feel the sub vibrating but there's no definite improvement in bass in the car. The vibration of the sub is detectable but not substantial. I know the amp works with a 4ohm rear door speaker so I guess the sub is past it's best so it's hand in the pocket time for a new one?

I'd like to mount one on the shelf as OE so as not to take up boot space. I haven't got a massive budget so any suggestions would be appreciated (don't mind a used one as long as it works!).

 

[Bemmy]

Found a Boss Phantom 10" Sub on eBay - any good?

Boss Audio D10F - 10" Shallow Mount Car Subwoofer 800W Max Power

• Slim, compact 10" (25cm) shallow-mount subwoofer
• Maximum output power 800 Watt
• Nominal output power 400 Watt
• Cone Material: Poly Injection
• Magnet Structure: 60Hz
• Frequency response 35Hz-2.2kHz
• Sensitivity (1W/1m) 94 dB
• Impendence: 4-ohm (Single Voice Coil)
• Mounting Depth: 3-3/8"

I wouldn't mind fitting it as you have done yours but would prefer fitting it as the OE one.

 

[John]

Right, Sub out and wired as above, everything put back in and working.....sort of!

I can feel the sub vibrating but there's no definite improvement in bass in the car. The vibration of the sub is detectable but not substantial. I know the amp works with a 4ohm rear door speaker so I guess the sub is past it's best so it's hand in the pocket time for a new one?

I'd like to mount one on the shelf as OE so as not to take up boot space. I haven't got a massive budget so any suggestions would be appreciated (don't mind a used one as long as it works!).

Yes, I'm not hugely surprised by that. I think MB sometimes get their speakers from a jumble sale and then ask a top audio specialist to do something with them.

Well, at least you've reached a stage where you have tried what you already had and you've lost nothing but a bit of time but gained a fair bit of experience.

Found a Boss Phantom 10" Sub on eBay - any good?

Boss Audio D10F - 10" Shallow Mount Car Subwoofer 800W Max Power

• Slim, compact 10" (25cm) shallow-mount subwoofer
• Maximum output power 800 Watt
• Nominal output power 400 Watt
• Cone Material: Poly Injection
• Magnet Structure: 60Hz
• Frequency response 35Hz-2.2kHz
• Sensitivity (1W/1m) 94 dB
• Impendence: 4-ohm (Single Voice Coil)
• Mounting Depth: 3-3/8"

I wouldn't mind fitting it as you have done yours but would prefer fitting it as the OE one.

Never heard of them but to be honest so I would guess they are at the budget end of the market - so I couldn't comment on whether they are any good or not.

Nothing wrong with that sort of thing and for the money, you may as well take a punt on something like that as the amp is not premium either.

Sometimes budget stuff can produce good results and you've spent bugger all which is nice.

I had some great results with budget 6" x 9" eliptical full range speakers, running from a fairly decent head unit, in a MK4 1986 Escort (my 2nd car back in 1995 on a budget!). So many people thought I had a subwoofer but I couldn't be bothered to install one so that was nice...

Anyway, the key thing here is your amp produces 1 x 180 Watts RMS @ 4 Ohm mono and the subwoofer is rated at 400w RMS @ 4 Ohm impedance.

This, as a general rule of thumb, is a good place to start i.e. amp is about half the power of the maximum of the speaker(s).

It's quite a high sensitivity which is also good as it will be louder than say an 87dB (1w/1m) subwoofer.

The only thing I am not sure about is whether it is suited for an enclosure or not. When you are installing a subwoofer on the parcel shelf with no box but you are mounting it like I did, it is known as "infinite baffle" (the pieces of MDF are the baffle). Subs work best in the setup they were designed for so you want an "infinite baffle" or "open air" subwoofer ideally. "Open air" just means you mount it without the baffle. These terms relate to not having an enclosure (box).

By the way, what I've explained previously about mounting the sub on the parcel shelf is what I had in my W211 E55.

I don't have that car any more and in my current steed I have one of these:

HO112-W6v3

It kicks rse! It's setup so I can remove it should I need the whole boot for anything.

But, if you don't want the hassle of removing something to use your boot, mounting on the shelf is one way of doing it.

This is how I did it previously:

I used 18mm thick MDF.

Measured the diameter cone edge to cone edge (i.e not including the mounting rim of the subwoofer with the holes in it - so if you put the MDF on the sub, all you would see is the cone), drew out the circle on the MDF.

Cut that out with a Jigsaw and then cut out a square around that - maybe with an 1" from the edge of the square to the circle at the 4 thinnest points.

Did the same thing twice and initially created 2 to put together (I discovered the throw of the sub meant it actually hit the parcel shelf so I did a third!). As the sub you are considering is shallow-mount, it should mean the throw of the cone is not as far. Although don't forget, you won't get quite as much bass pound for pound because it's the throw of the cone which creates the sound waves!).

I used a piece of paper and a pencil sideways up underneath the parcel shelf to create a replica of where the holes were - this gives you a template of where you want your bolts to stick out of the top layer. If you look in my earlier picture of the parcel shelf in a W211 E Class, you can see a larger hole which becomes a smaller channel (you can see one clearly and the sub is clearly mounted in one with something black there - you can almost see the second one to the right of that a bit further round albeit obscured by the foam) and there are at least 4 of these all the way around albeit I am not sure they were a uniform distance apart but matters-not.

I used bolts through drilled holes in the top layer of MDF (drill bigger holes to counter-sink the bolt heads into the top layer so it fits flush to the second layer) so they stuck out enough out the top and with a nut on the end.

I didn't mount MDF direct to the parcel shelf - I put something in between which I think was foam to create a more forgiving gasket as the parcel shelf is not flat.

I then bolted each layer to the upper layer but offset the bolt and nut positions each time so they didn't touch existing bolts or nuts.

I then screwed the sub into the bottom layer I think.

I put the whole thing together first and I could lift the whole subwoofer with MDF mounts up into those larger holes, then rotate, then do up the nuts from the top to bring the whole lot up to the parcel shelf.

I put sound deadening all over the parcel shelf. It could have done with more in the boot lid and inside of the outer rear quarter panels of the car. You want to cover up all the holes on the parcel shelf with it as you don't want any sound waves from the front of the sub cancelling-out those from the rear of the sub.

There may well be easier ways of doing it but I found this straight-forward to do.

 

[John]

Something like this is shallow-mount but also an open air subwoofer (and I've heard of it!):

Infinity Reference 1200S Car Stereo Audio System 12 Inch (300mm) Slim Subwoofer - Black: Amazon.co.uk: Electronics

Don't rule out subwoofers in an enclosure...

You do save all the hassle of messing around like I did before and if you get a smaller one, you can easily remove if required if you install using "banana plugs".

I heard one of the following subwoofers (8") in a Golf when I had my install done and it sounded incredible. They've really come on a long way:

MicroSub+™

 

[Bemmy]

I think I'm going to ditch the idea of resurrecting the OE sub after everything and go for an enclosed sub and connect as you suggested so that it can be removed when I have a boot full of grand-kids stuff!

I've found a JL Audio 10w0v3-4 10 Inch, 300 Watts, 4 ohm Subwoofer + 10" Bass Box on fleabay for £120 so I think that'll be the route I'll be taking.

 

[John]

I think I'm going to ditch the idea of resurrecting the OE sub after everything and go for an enclosed sub and connect as you suggested so that it can be removed when I have a boot full of grand-kids stuff!

I've found a JL Audio 10w0v3-4 10 Inch, 300 Watts, 4 ohm Subwoofer + 10" Bass Box on fleabay for £120 so I think that'll be the route I'll be taking.

I did consider doing the parcel shelf install in my current steed but I couldn't be bothered...

I still found things that wouldn't fit in the boot with a 10" sub magnet hanging right down not that I often had to do that - but I couldn't remove it easily if I wanted to.

I was on a tighter budget when I bought my AMG a decade or so ago so I wanted to keep the costs right down and I was happy with the existing system.

I think a box is better because you have the total space again.

Also, the box has been designed by the manufacturer in my case with optimal size, possible dimensions, wood thickness and porting - which are all important.

If you want the most bass at the lowest frequencies, short of going for a # order bandpass box, go for ported unit.

It's still quite tricky getting bass into the car in a saloon but with an amp chucking out 180w RMS bridged (hopefully that is what it is delivering) and a sub rated at up to 300w, that should be a good match.

The box is important to get the most bass out of a subwoofer but if you aren't spending much cash on a box, you can take a punt.

Ideally you want it made from thick MDF (heavy) so that it doesn't resonate.

I built my own box once back in the 90s having no clue it was important about the dimensions of the box although I did know the port length was important.

I literally made it the size of an Astra GTE 16V boot and put two Kenwood 8" paper subwoofers in it and two large ports.

I roughly copied one I'd seen but didn't separate the subs.

It actually worked incredibly well...

Which box are you looking at?

 

[Bemmy]

I'm guessing that as they are being sold together they are made for each other?

JL 10WOV3-4 Specifications:
Free Air Resonance (Fs): 32.09 Hz
Electrical “Q” (Qes): 0.640
Mechanical “Q” (Qms): 10.752
Total Speaker “Q” (Qts): 0.604
Equivalent Compliance (Vas): 1.095 cu. ft. / 31.01 liters
One-Way Linear Excursion (Xmax)*: 0.45 in. / 11.4 mm
Reference Efficiency (no): 0.154%
Efficiency (1W/1m)**: 84.07 dB SPL
Effective Piston Area (Sd): 48.909 sq. in. / 0.0316 sq. m.
DC Resistance (Re): 4.280 ohm
Nominal Impedance (Znom): 4 ohm
Thermal Power Handling (Pt): 300W
Driver Displacement: 0.034 cu. ft. / 0.96 liters
Net Weight: 7.50 lbs. / 3.40 kg

T1 Audio subwoofer speaker box
Black carpeted finish
MDF construction
Designed to fit a 10 inch subwoofer
1.1 cuft
Ideal for use with car stereo boot builds & installations
Side connection for connecting speaker cables
Sealed box design

Bass Box Approx. Dimensions
Height: 32cm
Width: 34cm
Depth Top: 19cm
Depth Bottom: 25cm

 

[John]

That depends on how you define "made for each other".

The subwoofer will fit in that box and it looks reasonably well-made from what I can see.

It's not the "optimal" size for it though and appears to be a "generic" box aimed at fitting the boot well (which is fine but not ideal).

The optimal size for it you can see here if you click on Specifications and then choose Sealed or Ported:

10W0v3-4

You could certainly buy that box and try it (it's sealed by the look of it as the exhaust ports are usually on the front of that type of box btw).

If it were me, I'd go for a JL Audio box instead and spend a little bit more (I did!).

Something like this where they have laid the inside out in a more clever way so you don't need such a large box for optimal performance (and it will urinate all over that generic box):

JL Audio CP110-W0v3 10" Enclosed BassWedge Ported Car Sub Subwoofer 300WRMS | eBay

(If this is spending too much, it might be worth going for a cheaper sub and purpose-box rather than a generic box.)

Why isn't it this JL Audio enclosure the same dimensions as JL Audio recommend for their sub?

Because it looks like this the below image inside - what they have done is allowed a lot more space behind the baffle (the "face" of a speaker i.e. the piece of MDF in this case that the subwoofer is screwed-to) for the lower frequency sound waves fired behind the sub to develop so that when they emerge from the exhaust slot, the lower sound waves are more audible:

 

[Bemmy]

Agree, I should go for the wedge enclosure you suggest. Looks good and will fit in the boot nicely. Bit more than I wanted to spend but the sub and enclosure are matched. I'll get that ordered up asap (don't tell the wife!)

 

[John]

Agree, I should go for the wedge enclosure you suggest. Looks good and will fit in the boot nicely. Bit more than I wanted to spend but the sub and enclosure are matched. I'll get that ordered up asap (don't tell the wife!)

I've been through the exercise of buying and trying stuff over the years and some stuff works and some doesn't.

I've learnt to aim for the best you can afford at the time within reason.

By the time you bought the JL Audio sub on it's on and that box, I doubt you would be a million miles from the JL Audio wedge and sub.

You can take the sub with you and use in future cars too (and the amp).

 

[Bemmy]

At long last all installed and working superb. The small amp and sub add just the right amount of bass without thumping the windows out.
Thanks to John for all help and advice (and patience!)

Now, do I remove the shelf sub to allow more sound in to the cabin or just leave it in place?

 

[John]

No worries - looks like a neat install so you've done well there.

I'm not sure it will make a huge difference because the weedy cone on that OEM stock woofer won't be stopping much bass passing through into the car.

The bass will be passing through all materials in the boot into the car as bass frequencies are not directional unlike higher frequencies.

As the parcel shelf is not acting as a baffle (i.e. you didn't mount the sub to it), it won't matter if you do remove it.

If it is something you will ponder, remove it and find out.

You can always put it back if it makes no odds (or launch it!).

 

[Bemmy]

I think I'll leave it for the time being, if I get bored one day I might just take it out but it's a lot of hassle if it isn't going to make much difference.