Need help tuning audio - I am getting fed up.

[frankenberrie]

My setup
Vehicle: 2010 Altima Sedan
HU: Sony CDx-GT930UI
AMP: Alpine M500
SUB: Alpine Type-R SWR-1042D 10" Dual 4-ohm
BOX: Sound Ordnance BB10-75V Single 10" Vented
FRONT: Polk Audio db 651s (not amp powered yet)
REAR: Disconnected

I need help guys! I am not sure where I should place the sub or how I should face it - toward the rear seats or the trunk license plate?

Also I tried configuring the amp by lowering the gain and raising the volume on the HU 1 click at a time till i hear distortion. I have the Bass EQ on the amp off but and the LP was set to 100 default. Any recommendations on these settings?

I am have trouble finding a sweet spot for my setup. I know I should be getting a nice thump but I cannot find it at all.

Thanks (if I left anything out let me know, I really wanna get this going - been messing around for a month)

[AppleBonker]

Tuning is a pain. I feel you on that.

Sub orientation shouldn't matter too much. If the sub is firing directly into the rear seats, you might lose a bit of volume. I've always pointed my subs toward the trunk lid from the rear seats until this car. Now it's in a corner near the tail lights and firing in the general direction of the rear seats.

For the sub, make sure there isn't a HP filter set, or if there is that it is around 20 Hz. Also, use a multimeter to gauge the output of the amp before connecting the sub. I think there is a brief explanation in the FAQ at the top of this forum. That should help you put out the maximum amount of safe power from the amp. Other than that, I would make sure the RCA preouts you are connected to are configured for the subwoofer. I'm not sure if I'm missing anything else here. But, you should get a decent thump from that sub. It's not going to shake the car apart, but it should add nice low-end to the system. I don't recall, is your enclosure sealed or ported?

[frankenberrie]

Thanks apple... its a vented box

This is what my amp settings are at right now:

[AppleBonker]

It looks like there is some subwoofer control in the settings of the HU. Make sure the sub doesn't have a cutoff frequency less that about 75 (that's what it looks like your amp is set at). And make sure the level in there isn't all the way down. I can't think of much else off hand, least not without playing with the actual car anyway.

Your setting for LP filter on the amp looks fine (I think mine might be crossed around 65-70 Hz ish for reference). The Bass EQ should always be set to zero, IMO. All it will do is boost a given frequency (I think) and keep your frequency response curve from being flat. The gain I can't tell much about without hearing the car and/or using a multimeter. I wouldn't expect you'd be able to dial it all the way up to the max without distortion, so I'm guessing the setting is probably about right. That is what led me to believe something may be slightly mis-configured in the HU.

[frankenberrie]

Everything on the HU is set to 0 with no enhancements - I am gonna try moving the sub to different positions in the trunk.. When I pop the trunk the bass is really loud - it doesnt seem to travel into the vehicle.. I even put the rear seat down... very fustrating

[DJ_B_Easy]

What is the resistance on the amp? I would guess its 2 ohms or less? If this is the case, did you wire both voice coils on the sub? If you didnt, then you are running a 4 ohm sub on a 2 ohm amp. If you did wire both coils, make sure you did it in parallel and not series. Parallel will bring the sub total resistance to 2 ohm, series would kick it up to 8 ohm and then you have big problem.

Apple correct me if I mixed that up, I know what it should look like but I get my terminology messed.

[frankenberrie]

The sub is wired correctly.. It came with 2 little wires to connect negative to neg and positive to pos on the sub

What I did last night was moved the sub to the front left side (near plate) of the trunk facing the seats. Turned the gain up slightly and set the LP to 75. I also opened the rear seat on the right side. This seemed to the do trick.