Hi folks,

 

I'm getting ready to upgrade the sounds in my car. It's got a normal MY16 MIB2 Amundsen. I've already bought a small Vibe 4 channel amp to power 16.5cm Focal Access components that will be going in the front doors.

 

I was not really thinking about adding a sub until I found the amp above will give me RCA outs if not connected to speakers, so suddenly I have the choice of easily using the rear channel for bass  

 

But I have a few options, and I can't decide

 

1) I have, from previous installs, a shallow box mounted RF 10" punch sub (http://www.caraudiodirect.co.uk/subwoofers/rockford-fosgate-p3s-1x10), which would fit OK in the boot... but have to be taken out sometimes. This would be powered by either:

1a) a matching JBL 300w mono amp I already have... it's chunky and so there's nowhere obvious to hide this, maybe just about under the driver's seat, and would need a full fat feed from the battery.

2b) Vibe do a micro sub amp, pushes 400w @ 1ohm. This would also need a full fat battery feed to run my 1ohm sub, but much easier to mount it out of the way in the boot, under a seat, or even behind the dash somewhere.

or,

2) an underseat sub. I like this JBL one http://www.caraudiodirect.co.uk/subwoofers/amplified-sub-boxes/jbl-basspro-sl-8-200mm-compact-amplified-car-audio-woofer and Alpine do something similar. Either would fit under the driver's seat pretty well, and only pull 10A so can be tapped into the fusebox (maybe the heated seat fuse location as mine aren't heated: if the wires are there, they should take 10A ok).

 

Edited to add: 3) Decent quality woofers in the rear doors with low-pass filters on, powered by the 4-channel, just for extra mid-bass fill... I mainly listen to rock/metal, so there isn't much in the way of very low lows.

 

 

I'm not looking for earth shaking bass, I like a clean, balanced sound.

If the underseat is likely to give enough, and makes for an easier install, then it might be worth splashing out (and maybe selling on some of the pile of kit I have accumulated over the years!)

Otherwise, it's picking an amp and then taking the whole car apart again, just like the last few... but I'm not entirely sure I can be bothered...

Edited 23 December, 20196 yr by Defblade

If you only want a 10", could you get one of those ebay boxes that moulds into the side recess of the boot? Might reduce the need to remove it. 

 

If you're going to amp the door speakers, presumably you're willing to run speaker cables to them from the boot? If so, you might as well run a power cable from the battery to the boot while all the trim panels are off. 

The amp for the fronts is tiny and will be going behind the dash; it connects with a T patch lead (like a bluetooth/handsfree module). And I'm not looking at massive power (65w RMS per channel), so the OE speaker wiring will be fine

 

On the whole though, budget and some sense suggests that using the kit I already have is far and away the cheapest option, and likely to be the best SQ result too, so probably the one to go for. I'm planning on the amp going under one of the front seats to limit boot space used; and then I'll just have to run the one speaker wire to the boot. If I have trouble tucking the JBL amp under, I'll buy a micro one like the Vibe I mentioned above.

 

I have been considering cutting up my parcel shelf (or making a new frame) and recovering with acoustic cloth to let more bass into the cabin... but then I might end up having to deaden all the boot panels to keep the road noise down, too... we shall see (or hear?!)

In case it is any use, I have had and used the amp in question.  The RCA's are not very well grounded which gave me all sorts of problems connecting to another amp for the sub (in this case the sister Vibe sub amp).  65w is not a lot (and tbh the power rating is probably a bit optimistic anyway) for a sub.  You potentially risk damaging the sub AND the amp due to clipping.  This amp isn't designed to be bridged either, unlike the Pioneer equivalent.  That means you will be stuck with 1 channel delivering 65w at 4 ohms (this amp is only designed for 4 ohm output).  While theoretically this amp can run off head unit power, do remember you will be limited by the fuse.  If you are running a sub off this amp it will demand power (at volume it also gets quite hot).  I have no idea what the stereo power fuse in your car is rated at, but the Vibe 65.4 has a 20 amp fuse. The 400.1 (which from the top of my head puts out 175w on a single channel at 4 ohms) ships with a 35a fuse.  Wire thickness is also something to consider - is the stock wiring to the stereo loom designed for and additional 20a running through it?

 

In short you would probably be better buying one of those underseat sub kits as 65w isn't going to do much with a sub woofer.

 

Personaly I ended up with a Pioneer DSP to get me a clean signal and ran the two amps separately off a proper power feed and earth.  I had good results with a Hertz compact 8/10 inch sub.  This was in a fiesta though.

23 minutes ago, Tarby said:

In case it is any use, I have had and used the amp in question.  The RCA's are not very well grounded which gave me all sorts of problems connecting to another amp for the sub (in this case the sister Vibe sub amp).  65w is not a lot (and tbh the power rating is probably a bit optimistic anyway) for a sub.  You potentially risk damaging the sub AND the amp due to clipping.  This amp isn't designed to be bridged either, unlike the Pioneer equivalent.  That means you will be stuck with 1 channel delivering 65w at 4 ohms (this amp is only designed for 4 ohm output).  While theoretically this amp can run off head unit power, do remember you will be limited by the fuse.  If you are running a sub off this amp it will demand power (at volume it also gets quite hot).  I have no idea what the stereo power fuse in your car is rated at, but the Vibe 65.4 has a 20 amp fuse. The 400.1 (which from the top of my head puts out 175w on a single channel at 4 ohms) ships with a 35a fuse.  Wire thickness is also something to consider - is the stock wiring to the stereo loom designed for and additional 20a running through it?

 

In short you would probably be better buying one of those underseat sub kits as 65w isn't going to do much with a sub woofer.

 

Personaly I ended up with a Pioneer DSP to get me a clean signal and ran the two amps separately off a proper power feed and earth.  I had good results with a Hertz compact 8/10 inch sub.  This was in a fiesta though.

Most importantly perhaps, the amp in question doesnt have a low pass filter - you will be feeding the sub a full range signal which is a sure way to kill it unless you put an LPF in somewhere!

10 hours ago, Tarby said:

In case it is any use, I have had and used the amp in question.  The RCA's are not very well grounded which gave me all sorts of problems connecting to another amp for the sub (in this case the sister Vibe sub amp).  

 

 

I've no intention of running the sub directly from the Vibe 65.4... but I am planning to use its RCA output from the rear channel to take the signal to another amp (and that's where the high gauge wiring will be! Also, has LPF on it; already matched to the sub from two previous installs  ), so could you expand on the RCA problems you mention, please?

13 hours ago, Defblade said:

 

 

I've no intention of running the sub directly from the Vibe 65.4... but I am planning to use its RCA output from the rear channel to take the signal to another amp (and that's where the high gauge wiring will be! Also, has LPF on it; already matched to the sub from two previous installs  ), so could you expand on the RCA problems you mention, please?

I had trouble getting a clean signal from the RCA out.  Was the classic grounding whir/humming on acceleration.  Tried putting in an isolator circuit, improving the grounding of the car, changing the leads, replacing the cabling, etc but to no avail.  I also tried wiring the amp with its own dedicated power and ground from the battery / chassis but there was no improvement.

 

As soon as I took the 65.4 RCA’s out of the equation the problems stopped.  I could have just got a slightly defective unit, but I’d suggest that the internal grounding of the amp (bearing in mind it is a cheap unit) isn’t the greatest and it maybe doesn’t have the best noise suppression circuitry in the world.  Perhaps because the RCA’s are both and input and output on this amp?  Interestingly if I removed the RCA’s from the sub amp but left them connected to the 65.4 the issue was still there on a reduced level.  TBH the problem reminded me of issues with cheap line level converters.  It definitely wasn’t the subwoofer amp as it ran great once not connected to the 65.4 via RCA.  
 

I ended up putting in a pioneer DSP anyway which was a great decision as it also cleaned up the factory butchered audio signal and gave me a nice clean out.  Not the cheapest option though but saved having to fiddle with line level converters and the like and potentially adding more sources for noise into the chain.  I have to say I was impressed with the Vibe amps, the above issue aside.  If you are running a 12v feed into the car anyway I’d suggest connecting the 65.4 to it as well instead of relying on the stereo loom to provide the power.  For the length of cabling in the 65.4 loom I was surprised how thin the power and ground cables really where!

Adding to this and having re-read your original post, if you are using a T-harness anyway an underseat sub like the pioneer and kenwood ones available just about everywhere will come with a loom similar to that used by the 65.4.  Theoretically you should be able to sort of chain them together though will need a bit of re-wiring on your part as you really don’t want to be feeding power to everything from the factory loom.  
 

If you go with the small sub that needs to be removed now and again along with the Vibe micro amp (it’s about 2/3 the length of the 65.4 btw) I highly recommend the Vibe fast fit connectors.  You could mount it to the sub box quite easily I imagine then it’s a case of remove the connector and remove the RCA’s and you are done!  
 

I forgot to say in my last reply.  When you connect RCA’s to the 65.4 there is a noticeable drop in audio volume from the speakers (front and rear).  I suspect it simply splits the stereo input into two!  Might help explain the noise issue too.

Edited 8 March, 20206 yr by Tarby

I think I'll have to check if my sub amp takes speaker line-in inputs as well as RCA, might be easier to split them out from the 65.4's loom.

 

You're right, of course, I probably should run a new live and earth to the 65.4 as well as my sub amp, if I'm doing it at all... more work, but worth it in the long run.