Sub excursion

[ND13]

Have any of you ever had a sub "lock up" playing a certain tone, if the sub wasn't allowed to fully move to its max excursion due to something impeding it(no grill)? It's firing into the back of the seat, BTW. I'm getting a grill tonight.

[MacLeod]

Off hand Id say that if a sub has stopped moving its exceeded its suspension limits and is now a fancy paperweight.

[ND13]

Originally posted by MacLeod
Off hand Id say that if a sub has stopped moving its exceeded its suspension limits and is now a fancy paperweight.

No it works just fine, it was just hitting the back of the seat, so a grill will have to be installed. I've just never heard one do that before.

It hadn't stopped moving, it was stuck at a certain frequency(for lack of the correct term), and was moving most freely. It was almost like a test tone.

[neomagus00]

i'm not entirely sure what you're describing, but it sounds pretty interesting... could you go into a little more detail, just to satisfy my curiosity?

[ND13]

Originally posted by neomagus00
i'm not entirely sure what you're describing, but it sounds pretty interesting... could you go into a little more detail, just to satisfy my curiosity?

It's really hard to explain without actually seeing it occur. I would equate the sound to a test tone being played at somewhere in the 60 cycle range at about 100 db. It would occur at about 1/2 to 2/3s volume, when the sub would throw into the seatback. The seatback wouldn't allow full excursion which would throw the sub into "that mode". We looked at every connection, amp settings, etc., etc... and found no other reason for it. Just to be safe, though we wired up both sets of terminals(dvc) directly to the amp instead of jumping one to the other. We also put a grill cover over it to keep it from hitting the seatback. Hopefully this helps clear it all up. I've installed probably 150 car systems back in the day, and had never seen this happen. The only reason I didn't install this myself is due to time constraints and my lack of patience when it comes to new toys.

[neomagus00]

okay, so you'd be playing music, then at a certain volume level the sub would begin to hit the back of the seat, and after that point it'd only play the ~60 Hz note? is that right?

how did you get it to stop? did turning the volume back down fix it?

[ND13]

Originally posted by neomagus00
okay, so you'd be playing music, then at a certain volume level the sub would begin to hit the back of the seat, and after that point it'd only play the ~60 Hz note? is that right?

how did you get it to stop? did turning the volume back down fix it?

That's about as close of an explanation as I can come up with. Like I said, it's something you'd have to see/hear for yourself. So far since the MMC6500s were installed, the sub was wewired and a grill installed, no problems(fingers and toes crossed). The Polks were finished this morning and sound great, but I still haven't fine tuned the system yet. I've got to turn the gain on the amp that goes to the Polks and adjust the crossover. They'll handle alot more bass than the KW coaxials would and I'd love to get more midbass in the soundstage.

[MacLeod]

Dont forget to take into accoun the MMC's will need a little break in time.

I noticed my MM6's fleshed out nicely after about a month.