shagged MY05 McIntosh sub

[SegR]

Well it looks like my sub may be shagged. I can't see anything obvious with it physically (wiring looks ok at the amp and sub ends, cone intact and it seems to be physically secure in the parcel shelf) but after the last service (suspiciously) it's producing a very faint sound and now has added buzz and crackle when the bass of music kicks in.

I've disconnected it because it's bugging the crap out of me. (is this likely to have any ill effect on the amp? Driving an output which is not connected?)

Is this likely to be anything other than the sub itself? Might it still be an amp or HU problem?

Also if I take this to a place specialising in car audio are they likely to be able to source a replacement sub (assuming they find it to be at fault) or would I be better off sourcing this myself? (hell if it's just the sub which needs replacing I could do it myself; I just may not have the skill to diagnose which part is at fault).

[garbo41610]

Sounds like the sub is buggered mate. It is probably the voice coil. But its a great opportunity to upgrade now. You're in queensland so if you are anywhere near northfield car audio then I'd suggest giving them a call. They do great work and should be able to give you advice on a decent replacement free air sub, if that's the route you want to go down. Otherwisde you could look at putting in an efficient 10" or 12" sub.

Disconnecting the sub is probably a good idea and make sure the cables don't short out on the car body etc obviously.

[SegR]

Yeah I've tied the cable away from stuff and it has a plastic plug which protects the conductors pretty much anyway.

I wasn't that impressed with the stock sub anyway but who knows, maybe it was already on its way out. Can anything be done regarding an acoustically improved enclosure under the rear parcel shelf? Or might a different sub perform slightly better?

I don't see an air-filled boot being optimal!

[garbo41610]

The sub will be designed to work in a free air set up. I wouldn't bother making up an enclosure for it, just replace it with another sub that is suitable to be used IB (infinite baffle)/free air.

You want to find a sub with a high Qts, low Fs and a high Xmax. Infinite Baffle isn't the ideal set up as you lose output from the sub but there are speakers designed to work quite well in this situation. Look for something with stiff suspension... Coupled with some dynamat on the top and bottom of the parcel shelf and a good solid mounting will give you some decent results. You have to remember, most if not all 6.5" splits are designed to work in an infinite baffle set up and you can get some very good mid bass out of some 6.5" drivers even without using dynamat.

Something like the Vibe Space8 would do nicely like in Mihai's set up but there are possibly some issues with Vibe's build quality of late.

Email Marty from fhrx studios here in sydney or a lot of queenslanders are happy with the work done at Northfield Marooka (http://www.northfieldcarsound.com.au/) so perhaps email them for some advice on suitable subs. Otherwise you can look at getting a small enclosure made up for the rear wheel arch and putting in a 10" or 12" sub.

[Gambit]

i have one for sale:

viewtopic.php?f=3&t=11397

[garbo41610]

I thought you sold it already LOL... If the OP doesn't want it, I'll take it

[SegR]

Thanks garbo, very helpful. It's good to have some background to validate what the sales guys throw at me

Gambit thanks for the pointer to that. Looks like garbo was in first anyway and he has been helpful so he can have first crack at it and I'll consider it in a week if that falls through.

Will get on to northfield but flat out this week with work.

[SegR]

Northfield recommended the vibe space 8 to replace this. Any comments?

[garbo41610]

Mihai slapped one in his car and he was pretty happy with the results.

They are a very nice driver.

[SegR]

What a retard... I don't know what was going through my mind, but I just checked my notes and it was an ARC 8 they recommended, at $279 plus installation. D'oh. Anyone familiar with this one? A bit of quick googling indicates generally positive comments.

Audio Express can do a Rainbow 8 or Rainbow 10 in an enclosure for less than this so... I just need to figure out what I want to do! (wasn't keen on losing boot space)