Tuning/Install help w/ Alpine Components
 

Hi,

I'm not really sure how to explain the problem I am having so I will dive right in.

Setup:
Type-R 8” (SWR-823D, 4Ω) (Inside a ported box made by Alpine)
Alpine MRP-M500 Mono Power Amp CEA-2006 Power Rating (40hm@14.4V = 1%THD+N), S/N 75dBA (Ref. 1W into 4Ohm):300W x 1
Alpine CDE-133BT Head Unit
8 Gauge Wiring Kit

HPF/LPF are both set to 80

Vehicle: 2007 Ford Ranger FX4

Everything is wired in and the head unit works and runs the four component speakers really well. The amp turns on with the head unit. I've got all the dials on my AMP at 12 o'clock. In the advanced settings on the deck I have the subwoofer set to "on" and the pre-out selection to subwoofer 2 (even though I only have one set of pre outs...weird). Oddly when it turn the setting to "subwoofer off" there is no noticeable difference. Its as if I have no control over the sub whatsoever (even though it is clearly getting info from the head unit).

The Subwoofer setting is set to level 6 out 15. The sub works; however, it acts as if it is really under powered. This being the case I have to turn the Gain up just shy of full power to get any noticeable bass out of the sub. When its turned up like this it sounds tinny (sort of hollow) and weak/distorted. I have a friend with the same sub and its pretty amazing the deep bass he can get out of it.

I've tried a new inline fuse and it didn't make a difference.
I've tried messing with all the setting I could find on the head unit without any difference.

If the amp ground was terrible would the amp even turn on? Could this be the cause?

I'm not really sure what to do next. Any help would be greatly appreciated.

Firstly, I feel for you man... Nothing worse than having you gear installed, only to have it not work as intended.

I am running an 8" Cadence sub in a sealed box, running at 300W @ 4 ohm, off a mono Kenwood amp. Your TypeR is a better sub than mine, and the fact that its in a ported box means you should be getting plenty of base. With that said, I'll see what I can do to help.

From what I can tell from the sub's model#, its a 2 ohm DVC driver. The coils are probably wired for a 4ohm load, to get 300W from the amp. That would be the only way to properly match these two components...

Just for shits and giggles, try turning your Gain setting to a more appropriate level, set the amps LPF to 120Hz, and turn OFF the HP and LP filters on the head unit and see if that does anything to help...

If you're anywhere near Brantford, Ontario, I'd be glad to help you in person...

Thank you for the reply.

Yesterday I talked a friend into letting me test my amp/sub in his vehicle. He has a similar Alpine head unit. He's running a 10" sub (rockford fosgate I think and an amp I didn't recognize: "Boss?"). Anyway, I plugged my amp/sub in and powered up the system. Same issue occurred. I then plugged my sub into his amp which has a 200w rms and with the gain set pretty high I finally got some bass out of it. I came to the conclusion after all of this that the amp was suspect. So I just exchanged the amp for another one.

I will turn the gain to a more appropriate level and set the LPF on the amp to 120hz as you suggested. You're correct in assuming that the sub is operating at 4 ohms.... at least that's what Alpine says.

Thanks again for the input.

When your Alpine sub was connected to his amp, you say that the gain had to be "set pretty high" to "get some bass". Without knowing exactly what his amp was set at, it seems strange that the gain has to be increased in order to start getting bass from your sub...

That's the instructions straight from the owner's manual. I would set the head-unit's volume with the subwoofer output OFF, to determine maximum volume without a distorted signal. It should be easier to hear any distortion without the subwoofer pounding away. Then turn the Subwoofer output back on, and slowly bring the gain up. With a 2V pre-out, my guess is that you would be at the 11oclock position on this particular amp.

Not to point out the painfully obvious but one or more leads on the subwoofer could have come loose in shipping/handling. Test the ohmage on each coil while playing with/moving the appropriate/attached coil leads.