I am running two Type S 12" subs in a prefab box off a MRD-M1005 mono-block.

It sounds like mush when comparing the same sub/amp setup in the original Alpine ported enclosure that they were in first. Unfortunately, that enclosure was far too big and fit very poorly in the boot, necessitating the move to the prefab enclosure.

The enclosure is currently facing backwards in the boot with the box pushed up against the back of the rear seats.

I attended a reputable car stereo place in Brisbane today and spoke to a fella there who suggested that the whole shebang would sound miles better if the sub box was turned around to face the seats and a blanking/sealing panel installed across the back of the enclosure to seal the rest of the boot off rear of the bulkhead.

Anyway, long story short, I'd like some thoughts on this from those who know more about it.

Cheers......

Some people say facing forwards sounds nicer but you do usually lose a bit of volume due to cancellation that occurs in that position.

I found that putting it at the rear of the boot facing forwards give the best of both but that you don't really have a boot left.

Sound deaden your entire boot, I know it made a huge difference in my system...
Due to the size/shape of the box im confined to having them sit on the step facing rearwards (I have 2 x 12" Type-R's) and it also sounded a little "Mushy" as you say...
Probably not as bad as what your saying as the type-r's make up for mushiness with large amounts of raw power...
Anyway, pull your boot liner off and sound deaden EVERYTHING, I used Flashtac (Check the guttering section of Mitre10 etc) its hella cheaper then buying "brand name" sound deadener, and its actually made of exactly the same stuff.... Aluminium sheet over tar...

What I did with mine was to run the flashtac over all the raised bits in the back of the bootlid, you'll notice they have holes there to breathe through the metal, cover them all up...
I then also used some silicon based sealer (I used Sikaflex, a little bit messier then clear silicon sealer) around all the edges and seams of the bootlid.
The result - Same as sound deadening your doors, when you close the boot you get a satisfying CHUNK with no reverberation, and with the subs on it makes them much louder in the car, its like it uses the whole boot then as a big sub box, you'll be able to notice the difference in sound when somebody opens your boot and all the bass dissapears/sounds hollow...
Total cost of mod, about $25 for a roll of Flashtac and a tube of silicon sealer (ie. Sikaflex)

I'd recommend using proper deadener... I used Flashtac on my old car and it worked well after putting 2-3 layers on but that made it a lot more expensive than $25.

Also, Dynamat Extreme and the other top end deadeners aren't aluminium on tar, only the cheaper ones.

What about the spray on / brush on type sound deadener?
Looked fairly generic, black can, It can be found for about $30 for a 1Litre container from Bisset's Auto spares...
Saw it but wasn't too sure if it would be any good, didn't want to be painting thick black glue onto the insides of the car for no good reason.

EDIT:
Also, I found the Flashtac sat and moulded perfectly around the bootskin support structure, and was able to do the entire boot with a single roll, it made a noticeable difference.
Given I haven't even glanced at sound deadener since I actually used it last about 6 years ago, and at that time I was gobsmacked about the price (About $150) for a Stinger sound deadener kit from JB Hifi, which was, essentially, tar/roadbase over thick aluminium based backing...
Technology may have changed but regardless, tar/metal sheet does the trick.
At the same time my mate invested in an expensive sound deadener that came as small sheets and needed to be heated first with a hairdryer and then stuck inside a door for example (Cant recall the name), it made a noticeable difference, but given the amount he had to use, and the cost, the cheaper option would still win
(It still appeared to be tar based, but as far as I can remember didn't have any metal backing, was like a solid card of roadbase )

Firstly you answered your own question as to why they don't sound any good, it is the enclosure so try some things like turning the box around and see if it helps, maybe try a different enclosure style...

Thanks....... but,

You've just reiterated my OP and answered none of my ?'s

Of course I know why they are sounding avg. What I want to know is if they will sound better IF facing fwd with a blanking panel. Now, I could just try it but my current sit'n means that I can't do it myself, which means paying someone to do it. I'm dubious as to the liklihood of this already, hence why I'm looking for answers on here first.

Anyone able to shed light on this point?