After 1600kms of listening to the stock system with one of the subs half-dead (rattling), its time for improvement...
At the moment i have the choice of replace the dead 8 inch driver for $54 brand new from holden or find a pair of "better" replacements.
Can anyone suggest any decent infinite baffle 8 subs to replace my factory 8s?

The term is "Infinite Baffle" and I would suggest something with a stiff mechanical suspension like a DD1508 would be a good option.

Make sure you Dynamat the rear shelf well too!

If you are going to leave the other equipment in there and not upgrade to a biger amp to run the 8s something more efficient like Rockford Fosgate P1 woofers would be the way to go

I think you mean infinite baffle. From memory its a Bose system, which means it is very possible it could have a extremely low impedence to extract the most power from the factory amplifier - the Bose system in some Audis have 0.5 ohm stereo drivers!

Then again, thats going off my memory and could be another system.

thanks i fixed the spelling up guys...
My particular car already has a Cadence Z3000 amp providing 150W rms to each of the 2ohm 50 watt holden subs. (part of the Eurovox Maestro system)

This is what the factory sub mount looks like. It is positioned over the top of the factory 6x9 hole, therefore the magent of the sub needs to be small enough to fit or be slimline enough to not protude deep enough to make contact with the shelf itself.

I would suggest (as i have many times ) a pair of H.A.T. L8 designed specifically for I.B.
here

You want to look for a driver with a qts higher than 0.4 ish, and also a low fs.

How's a qts of 0.765 and fs of 40Hz?

Does anyone know pricing on the Legatia L8 raw drivers and where to buy from?

You really need a subwoofer with a Qts of 0.6 or higher. 0.4 is too low. Sadly no one I can think of makes and 8-inch IB subwoofer. Actually IB subwoofers are very rare. The only one I've heard recently that impressed me was a 10-inch JL Audio Marine model which was amazing but costs $498 and won't fit in an 8-inch hole.

Legatia L8 Thiele-Small Parameters
Overall diameter: 215mm (8.5-inch)
Mounting depth: 92mm
Bolt Circle Diameter: 195mm
Mounting hole: 185mm
Pnom (without crossover) 75W (AES Standard)
Pmax (without crossover): 150W
Pmax (with recommended crossover): 250W
Frequency range: 40Hz – 2,000 Hz
Sensitivity: 87dB (2.83V/1m)
Mms: 31.5g
Cms: 454 um/N
BL: 5.99 T*m
Voice coil diameter: 35.55mm (1.4-inch)
Impedance: 4 Ohm
DC Resistance: 3.4 Ohm
Fs: 40Hz (free air)
Qms: 7.35
Qes: 0.693
Qts: 0.765
Xmax: 8.5mm (one way)
Vas: 26L
Sd: 0.02 m2
more
And here's a link to the Forum:

Cost : the RRP is around $600USD for a pair but Scott often has sales. They also Hand match their drivers now.
Also nows the time to buy in US as the AUD is strong at 0.90USD If your still interested contact Scott by email sales@hybrid-audio.com

Rainbow W200. they are sorta of a 8" midbass driver but can play sub duties extremely well. to play low they would need an enclosure otherwise they would bottom out to easy. but they are very slim very small and put out alot of bass for the size.

Where can i find price lists for them?

edit: just realised they are neither profi nor vanadium

Mate speak with George (icacha) at Precision in Sydney. They are the Rainbow distro, George is a great bloke and full of knowledge.

www.precisioncaraudio.com.au

Precision Car Audio Engineering are the NSW retailers, there is also a Victorian retailer for Rainbow. Check out http://www.mobilefidelity.com.au/dealers.htm for dealer contacts.

Ant

Ahhhhhhh cool, I didn't know Phatt were Rainbow dealers.

Call them then mate, otherwise I will talk to you further

Approaching IB conditions, the enclosure (boot) will have very little affect on the q of the speaker so qts will be very close to qtc. 0.5 is critically damped and 0.707 is maximally flat fr, anywhere between these figures is a fair compromise. Also keep in mind xmax with how much output is to be expected, especially with a small driver. Low end sensitivity is largely increased so power will not usually be such a problem.

DLS also have a range of subs that they specify suitable for IB. I think it is their classic series.

Just to clear that up. Its not DLS' classic series, but rather a model they have in their classic series. The model numbers at OA8, OA10 and OA12.

y dont you just make an enclosure underneath. Im using ID8v3 Subs in my Corolla 2 of them. Let you know how they go

for now, im just going to use one of my DD1508s running from 300w rms in a .8 cu ft box i have made (box came out of a vy) This will have to do until i can work out how i'm going to tackle the rest of the system

IDQ 8's!

I said exactly the same thing. Slaps Broadz.. now do et!

Just a bit of an update...
Installed one DD1508 in a .8 cu ft sealed box from 300w rms and imo, the stockers sounded better.
I then, installed the other matching 8 in a 1.3 cu ft ported box (from the jeep), with an estimated port legth of 330mm and sounds far nicer (and a lot louder) then sealed.
To put it simple the 1508s will not suit my application.... they require a box too large to suit the parcel shelf and require more power then i wish to feed them.

Who here has used or heard the IDQ8s?

My intention was to track down a pair of boston pro 8s

heard idq 8's - awesome.

After a few pms back and forth to drew, looks like i might give the ID8s a try...
Apparently IDQ8s are superceded and they are more a mid-bass driver wheras the ID8s are primarily sub-bass.

have you thought about using A.P. membrane??

OMG i aint heard of them in Ages are they the ones from USD Audio?

I.D. used to make an AP membrane. Might be hard to source now !!!
AP would mean competely sealing the boot from the cabin if the driver / membrane
is venting to the boot space, not easy to do with a ski port but very possible.

I'd also consider a Treo SSi 8", they're built for business...

surefire.... have a look in my other thread in the my rides section. There are pics of me trying to fit DD1508s. As the treo is roughly the same size, i doubt it would fit, and i doubt it would be much good running IB.

Blanky, nah havent even thought of AP, to be honest have never researched what AP is and how it actually works.... I'll go do some research and come back when i can understand it

What i'll probably do is start with everything else and leave stock subs until after first comp. That way i can have the judges oppinion on my sub bass and what kind of improvement i will need to do which i can then decide if IB will work or i will need to go camouflaged sub box with a larger driver.