Low pass filter for rear sub?

[tangcla]

Just wondering if I'm right in my assumption - that there's no lowpass filter for the sub on the parcelshelf, right?

Has anyone fitted one?

[cpitts]

Given what I'm hearing during speaker replacement, I'm tempted to suggest that it may have a band pass on it already.

I think (much to my dissappointment) that the amp may well have some form of cross-over network in it. The door channels just don't sound right on their own and when you fully fade to them (eg: full front, full left) there's a certain vocal range that sounds lacking, but the centre channel is quite strong. I suspect that there's a similar thing happening for the sub.

I suspect the centre channel is a freq mix from the Left and Right and possibly there's some form of HPF on the doors to allow the fade up to the centre channel to give artificial height/stage.

I'll hook up a full range speaker to the sub cable and see what sounds come out, soon tell if there's treble there or not.

[tangcla]

I'll hook up a full range speaker to the sub cable and see what sounds come out, soon tell if there's treble there or not.

Thanks would love to know. The bass does sound muddy, it wouldn't surprise me if there was a LPF but it's probably set too high

Are there any adjustments at all on the amp? I doubt it...

[Boxer]

Probably only muddy cos its cheap and is a free-air sub. I put a boxed (selaed) 12" on mine and got much tighter bass.

Free-air and to a lesser extent Ported subs on average amps is a recipe for muddiness. A sealed box will mask the poor damping factor cheap amps have. Poor damping factor= lack of control over the cone excursion and resonant harmonics create the muddiness or lack of detail.

[cpitts]

The amp is a fully sealed unit. I've pulled it appart as much as possible and haven't found any variable pots. Without drilling out rivets or spot welds, I'm gonna say it's fixed.

Deadening the parcel shelf and all doors makes a massive difference to the quality of the bass. It's not tight and clean as from a decent unit though, and if you look at the tiny little factory sub speaker, it's easy to see why.

Agree with Boxer on the decent amplification issue as well. There's only so much you can do with the supposed 50W being sent to that little cone. It probably pretty poor down at the very low freq end that's required for the sub to do a clean job.