iamsam

Hi all, 1st post. Just got an 11 xB a couple of weeks ago and have been browsing the forums looking for sub ideas. I've got the alpine HU and low expectations so I want something small, stealth and decent. I think of it as OEM+.

My first thought was to rock it like beef with an underseat sub (did you see what I did there, haha), but I want this installed in the next two weeks and elemental designs is 3 weeks out on a box. That led me to a local car audio place and they recommended I consider the passenger side trunk space where the OEM or JL stealth box goes. His reasoning was that the underseat sub would feel punchy whereas the sub in the hatch would sound more balanced. I've read on here that people think the sound is better balanced with an underseat sub, so I was looking for opinions. Especially on the punchiness of a sub right under the passenger seat.

I'm using one elemental designs 3.8 and will have about 150-165 good watts going to it. Price of either location is within $75 of each other. The underseat sub would definitely be more stealth, but I think this tiny sub in the rear would be pretty stealthy too. It needs .2-.35 and rockthebeef had about .31 iirc.

I don't have any plans to change out the stock speakers, amp them or enter any sound offs. Back in the day I ran some pretty decent systems, but that was then and this is now - with a kid, etc.

So, any and all input appreciated on the pros/cons of either location or what either one sounds like. Also, loving the xB. Coming from an STi it is quite a change, but I like the more relaxed ride.

/sam

Greg S

iTrader: (1)

I've got to disagree with that shop. I've got subs right up front between my seats in my Odyssey and they sound great there. Also the sound from all the speakers hits at the same time giving you a better sound stage and more cohesive sound. It's all a matter of how it's tuned and what the sub is crossed over at. I would recommend crossing the sub over at around 60 Hz. and letting the other speakers take over from there. You would be better off getting an amp to run the other speakers though. It'll make a world of difference in how clear everything sounds. I had planned to go under the seats with my 8s but they got turned in to mid-basses and put in the and I ended up with a 12" sub in the rear hatch door.

iamsam

Thanks for your opinion. I have heard both opinions, which is why I was curious about experiences from xB owners. My concern with putting an 8 in the back was how it would sound considering I won't be upgrading the other speakers too. I've also never heard any subs in an xB before for reference.

I actually have a second amp, an older Alpine F305. It matches the sub amp, an Alpine T302. The 4 channel amp is 30x4 @ 12v and 50x4 @ 14.4v. I read in the manual for the stock Alpine HU that it has 50x4 max. So, I'm guessing 20x4 rms, which isn't much less than the amp. By adding the amp I would gain better xover settings and some power, but would it really make much difference? I think of the Alpine HU as having similar power/quality to one you might buy after-market, is that not a good assumption? My original plan for the amp was to sell it to help finance the rest of the system, but I surely could keep it although I wasn't looking forward to having to make an amp rack and run wires for the speakers.

Thanks for the comments.

/sam

Greg S

iTrader: (1)

Keep the amp, it is infintely better than teh power in the headunit. That 50 x 4 rating on the headunit is at max power with tons of distortion. You're looking at more like 10-15 watts of RMS power, also the amp has a lot more headroom for peak transients. Also remember that when on the car runs at about 13.6 volts so you'll be running about 40 watts RMS.

KaneoheKoa

The greatest thing about adding a sub (underseat like mine or rear mounted) is the increased clarity and fullness in the sound. Adding an amp to the main speakers increases your clarity, sharpness and overall spaciousness.

But warned be, once you start tinkering and adding to your system/car, down the path to the dark side go will you. Lost forever, shall you be!

iamsam

Based on this and the fact that I already have the amp anyway, I think I'll put it in. Can't hurt right? Question: In the past when I've amped my mids/highs they have been higher quality speakers taking in about 75+WRMS. I ran 12GA from the amp to the mids/highs and bypassed or removed the factory speaker wiring.
For this application (less power/stock speakers) can I just run speaker wire back to the head unit and pick up the factory wire there with a t-connector or something?

Thanks.

iamsam

Definitely looking forward to it. Should be done by end of next week.

You are correct Sir. I've been down this path before, so I'm aware of the slippery slope Even now I've been leaning towards putting the sub under the seat in case I want more later I can use the space in the back for a 10/12! Planning for something like that is the first indication I've already started slipping!

iamsam

So, anyone with direct comments on the differences in sound of a small rear-mounted 8" w/ 150WRMS vs. under the seat with that same config?

iamsam

Look what FedEx brought me today:



And b/c pics are fun, here is one of the 4CH amp mentioned earlier, an Alpine MRV-F305 circa 2001:

ScionFred

iTrader: (1)

I'm running the stock HU with Infinity 6.5 coax in the front doors, a Kenwood 120W rms mono amp (160W rms @ 2 ohm) feeding a 2 ohm ED SQ10 in a .3cf sealed down-firing box under the passenger seat. Before this I had a Pioneer 10" sub in a .66cf sealed box in back powered by the same amp. There's really no comparison at these power levels. The rear-mounted sub needed a lot more power just to keep up with the stock HU and front speakers. Another big advantage of the underseat sub is that you can crossover higher while still blending into the front sound stage.

iamsam

Thanks for the feedback - exactly what I was looking for since I can't actually hear any to sway me either way. Any pics of your setup? I can't imagine how an SQ10 is setup so it can downfire, but I'd love to see it to work out some more details on my setup.

I think I will end up putting it under the seat for the reasons ScionFred brings up and a couple of others. Will post pics when done.

Thanks everyone.

ScionFred

iTrader: (1)

If you search the XB2 section for 'under+seat+sub' you'll find a bunch of threads with some great ideas on box dimensions, design, sensor relocation, etc. Here are some pics of my setup: https://www.scionlife.com/forums/sho...8&postcount=18

My box was very easy, I bought it from ebay and added feet and a grill. Others have built custom boxes that really maximize the available space. In actuality my box is a little under .3cf and filled with poly.

Good luck.

iamsam

Thanks Fred. I actually did search quite a bit for those terms, not sure how I missed your thread from 2007, but a helpful read just now. I'll be going on Wednesday and see how much they can get down there with fiberglass. I'm even going to throw in the requirement of not relocating the sensor just to see if it can be done.

Thanks again.

ScionFred

iTrader: (1)

You're welcome. FWIW, relocating the sensor and wire harness is very easy. Just remove the push clips, bend the bracket arms flat with pliers and reinstall the sensor and wire harness on top of the bracket. There's plenty of room to move these up and provides about 2" more clearance for a sub box.

Good luck with it and be sure to post some pics when done.

iamsam

Thanks to everyone in this thread who provided feedback and those whose threads I got inspiration from like rockthebeaf and Darksides7. Link to Darksides7 thread that includes rockthebeafs stuff is a great start and mostly complete on the subject: https://www.scionlife.com/forums/sho...highlight=dark

As for mine, it turned out great. The darn thing is tiny. It goes back into the rear passenger well just enough to cover the edge of the floor mat like others, but ends at the front hump just before the heat vent. The top and sides feel like wood, but the bottom is definitely all fiber glass.

I did not need to relocate the sensor, I just had to zip tie the wire to the sensor so it wouldn't move left or right and get stuck between the sensor and the surround. The seat moves all the way back just fine.

The shop that did it said it is .35 w/ some polly fill added and it sounds really nice. It integrates with the factory speakers perfectly and sounds like a complete system now. I have about 160WRMS from an older alpine amp and it sounds nice. A bigger amp could certainly push it more, but as it is I don't have the gain all the way up and the subwoofer level is set to 2 on the HU.

I can tell that the sub is a better speaker (warmer, smoother, etc.) than the factory ones and as Greg S said in this thread, ampping them would be better. He was right and maybe I'll do that in the future.

All and all I am totally happy with the setup and recommend it to anyone. Using fiberglass a proper 10" could likely fit assuming you moved the sensor.

I'll try to get some pictures. My iPhone wasn't cutting it just now and I'll need to find the digicam with a flash.

Thanks again.

/sam

iamsam

I'm reviving this old thread to bring the story back around full-circle. The xB is gone (almost three years ago now) and I've had the underseat sub sitting since then. Just hooked it up and it still works great.

If anyone is interested in purchasing, DM me. It's also for sale on CL in Los Angeles, CA: Scion xB Custom 8" Underseat Subwoofer

/Sam