So I've got my 8W7 and 250/1v2 all hooked up and looking clean but I'm really dissatisfied with the sound. It seems to be missing notes and is very inconsistant with the volume. One note will hit hard, then the next couple notes, of the same note, will be much softer. I have a couple ideas but could use some input.

-I tapped RCAs into the rear subwoofer (6x9's in the rear deck) speaker wires and plugged them directly into the JL amps built-in LOC.

Is the cutoff of the BOSE amp too low? Should I use the rear door speakers instead to get some mid signals in the mix?

Or maybe should I disconnect and remove the 6x9s as maybe they are eating up some of the signal when they hit? Taking them out would also make a nice pair of ports into the trunk... with the seat back the insulation does a pretty good job of attenuating some of the bass.

I havn't propery tuned the JL amp yet, but I have it pretty close. It should be sounding ALOT better than it does at the moment. Do you think I'm on track with either of these options? Is it common practice to leave the stock woofers connected or should they be removed?

I've never integrated a sub into a stock system before, I've always gone the whole nine yards and replaced everything at once.

Thanks for the input.

 

I would agree, integrating into the factory system is slightly disappointing! I assume you are using a rear-channel signal splice as well? In any event, I left my factory speakers all connected (woofers included) and I don't really have any issues with volume. I suppose my main grievance is with the accuracy of the bass. But, this is par for the course when you wired using a rear channel signal. I want to think that the factory Bose system uses some sort of cross-over as I believe I recall seeing them in the rear-deck. I suppose this means your not getting the full signal if you splice post cross-over. I would contemplate running up the amps internal cross-over all the way up (rendering it useless). The woofer does a pretty decent job of responding to whatever frequencies it can without the need for a amplifiers cross-over. I imagine a 8" could probably benefit from some mid-range bass as well. I also left the Bass adjustment on the radio at mid-level so as not to ever over-exert the factory woofers. Good Luck!!

 

Ok so apparently I jumped the gun a little bit. I should have finished tuning the amp before I started fishing for advice. Like the JL manual says, the input sensitivity must be adjusted so 27.4 volts are output for the 3 ohm sub. I did that and now it is night and day. It hits hard and fast and is SUPER clean - yet remains musical and not obnoxious. I still need to mess around with the LF Boost, but it sounds exactly as I hoped it would. I can keep the bass/treble down low now and get more mids and more accurate highs from the Bose speakers.

I am beyond satisfied.

 

I am looking to do this also.. Do you have pictures of the sub in your trunk?

 

I will post pics once I have everything ironed out and the components are in their final resting places.

The trials and tribulations of working with a modern car continue... I checked all my connections and adjusted the input sensitivity yesterday as I explained in my previous post. At that point I thought everything sounded awesome. This morning, not so much. I am still missing notes and the volume is still rather inconsistant. I am tempted to try two things:

-Tap into the INPUTS of the bose amp rather than the outputs (thanks choice89)

-Disconnect and possibly remove the OEM woofers from the rear deck.

The way I see it, why keep two sub-par woofers if you just added a top of the line one? Removing them would improve sound quality as well. Not sure how it would effect the acoustics of the cabin though... It could end up being a horrible idea. As for the wiring.... looks like more fiddling is in my future.

I am still pleased with the overall performance, I just know it should sound even better.

 

I would be scared ****less tinkering with the factory woofers bro. I suppose I would worry about the effect (or lack there of) on the others speakers. Is there a separate amp for the woofers alone or is it multiple channel amp (for all the speakers)? My assumption is that it is a single amp running the interiors plus the woofers. Food for thought...

 

I hate to tell you to spend more money but what you may need is a line level converter. This would take the speaker level input you are tapping into and convert it to a line level input for you to run to the amp.

 

Thanks for the input guys,

imcgjh84 - You are correct. It is one amp powering everything....Looks like one giant aluminum heat sink. After soldering my leads to the inputs after work I determined that I am not touching the bose system. I tapped into the amp rear inputs but that's as far as I will go. That sh*t could get messy quick I think.

Boone- I have a nice aluminum Stinger adjustable Line-Out converter floating around somewhere in my toolchest, but I was told I don't need to use it because the JL slash series amps have one built in.

Here's how I have it set up now, and I have fixed at least one of my problems:
RCA cables spliced directly into the Rear Right/Left INPUTS to the Bose amp. It is my understanding that this is a low-level signal, so the JL amp input setting is set to "low". Before I was using the high-level Bose OUTPUTs, and the "high" setting on the JL amp. I didn't have much time to test it out, but my initial impression is that I no longer lose the frequencies I was lacking before. It is incredibly quiet though. I did what the JL manual says, and got a 50Hz 0dB test tone, cranked the volume to 75% and set the AC current of the speaker outputs to 27.4 volts using the input sensitivity ****. With this setup, you would never know I did anything unless you CRANK the LF Boost on the amp.

My thoughts and plan for tomorrow unless someone else chimes in is to turn the volume up to only 50% and do the same thing, and if that doesn't work, or sounds bad, do the same thing with the bass turned allll the way down on the nissan EQ.

Whew..... Hopefully in the end anyone looking to add an amp will benefit from all this.

 

I am happy now. I cranked the bass and treble on the stereo all the way to the left and turned the volume more towards 2/3 full. Calibrated the input sensitivity and I think I'm in a happy place now... The bass is EXTREMELY accurate. It is tight and clean and sounds amazing. It is not a setup that will make every song a bass track. With some songs the woofer 'melts' in with the other speakers, which to me is a good thing. I'm not trying to make the star spangled banner bump. In songs that clearly have strong beats, like most Rap, you would never believe that it was an 8" woofer. With Rock songs, the bass lines are incredible and you can hear every note clear and tight.

So my final synopsis is this: If you are like me and are looking for something to round out the Bose system, NOT to rattle your trunk bolts loose, and value high fidelity sound and tight clean bass, then I highly reccommend this setup.

If you want some real thump, I'd step it up to the 12 or 13.5" W7.

I'll take some pics soon, I still have some loose wires to find hiding places for. My springtime project will be to build a custom box to fit in one of the rear nooks of the trunk.

 

Cool. I'm glad you managed to get everything sorted out. There is nothing like the satisfaction of a successful project.

 

Can u update and add pictures to see the results big man..?..thanks!

 

Here's some pics of my final (until spring/summer) install. I have since tucked the wires out of sight, but when I took the pic it was 11 degrees out. Its funny, when you see the woofer you really do think "Aww isn't it cute." Custom box to utilize all the room in the righthand trunk nook and get a nice flush install with the trunk is the next project, hopefully kick it off in the springtime.

 

Congrats, it looks like it will pop the trunk lid with all the air that thing is moving Nice thought on keeping the trunk space available but (if you never put anything in the trunk it wouldn't matter) it looks as though the cone is awfully exposed. Any thought on a small "cage" to protect the cone (or is that what you were refering to as the custom box?)

 

Thanks, I actually ordered the JL Grille today. Until that gets on, there will be NOTHING put in the trunk, lol.

 

I've got 4 Kenwood components (1 in each front door, 2 in back dash) running on a Kenwood 500w amp. And 2 Kenwood 12's running on a 1000w Kenwood amp. It's gotta pretty clean sound.

 

A few things bro:

1: should have ported that 8, sealed is ok but that 8w7 needs to breath

2: your way underpowered, why feed 250 when it can take 500rms? I was told these 8's can take 700+

3: if you where gonna go single sub and place it all the way in the rear you should have gotten a 10 or 12 that 8 is gonna get...........well you"ll find out!


Im installing dual 8w7's 2cf slot port tuned to 34htz on a PPI d3000/1, roughly 1200w @ 1.5ohms. Yea a whole lotta muscle, but thats what gains are for.

JL's are expensive as ***, anything other then an 8, I would have chosen another sub (DD, Sundownz, RD, IA, RE)

have you dynamated you trunk yet, if you havent you WILL....

 

Thanks for the input, now heres some questions for you;

I was considering building a ported box... Will it help that much with the 8w7? I am still in the concept stages, I plan to build one in the spring. Any input on that would be appreciated, as i've never built a ported box - only sealed.

The only reason I went with the 250 is because that is the "reccomended" amp that JL lists in their documentation. I was considering the 500, but went with the 250.
I'm very glad you said the things you did, because sure enough, I am feeding 250W to a 500W RMS woofer. You have opened my eyes to realize that it is underpowered.
I just ordered a 500/1, and actually for not much more than what I paid for the 250. Hopefully I can sell it to make up some of the cost. In that case, It was just a $30 investment. Basically a no-brainer.

3- I'm not sure what you are saying, it actually sounds the best in the back corner. I've moved it around a bunch.

I agree with you on the price, especially after reading reviews. To me, for the sound I was looking for, anything other than an 8 would be a waste of money.

Yes, I put Stinger RoadKill on my trunklid. I still need to put some on the back of my licence plate. If I can figure out how to get the performance you are talking about then I will def have to use the rest of the trunk kit.

 

My 2 8w7 will be here tomorrow, and my box should be ready next week. I feel like a kid a week before Christmas!

I was initally doing a single Polk SR124 in a sealed enclosure, then an IB setup like (phxgold) on the deck, then I heard 2 JL 8's and it was game ova!

Now dont get me wrong we are dealing with 8's, but when I heard 2 of these in the trunk of an Accord I was shocked, he was running 2 off a JL1000/1.

Its just the look on peoples faces when they see the lill bulldog back there in that big azz trunk!

 

Thanks man, I will look into going ported, but I wana see how it sounds first. I like the idea of 'molding' the box against the edge and maximizing the remaining trunk space. We'll see though, when the time comes I may be lazy and shop around for custom jobs.

As for dialing in the gains... My plan was to multi-meter them to spec, see how it sounds, and then back off a little bit if need be. You think thats a good plan or do you think I should dial it in a bit below spec to be safe?

I am shocked at the quality of the 8's... and i'm just goin with 1... It is absolutly what I was shooting for, I just want it a tiny bit louder. The 500/1 should take care of that I hope.

 

The combination of the 500/1 and a ported box would be more than enough for your needs! Use the multimeter to set your gains to specs and you should be good to go.

Seriously look into a ported box to get the most out of the w7!

 

Have you ever heard the term "leaving money on the table?" Thats what your doing to a sealed 8w7, let the funk hit the fan man!!

 

Ok I'm sold.... not till spring/summer though.. or maybe when I sell the 250/1 I'll use that money...

 

Just got my 2 8w7's today!

Impressive lookin' lil buggers!

 

Congrats! Ya those little babes are crazy.

 

8's are the hottest thing right now and only JL, ED, Sundownz, & DD, are making them worth a damn!

 

Hell yeah. Def post some pics on here when you get your box all set.

 

proly a lil late but you got youre back seats to fold down??

 

Ya, only the premium and sport packages have the solid rear seat with arm-rest pass through. All others have split 60/40 folding seats. In the trunk there are two gray straps dangling down way up by the seats. You give one a yank, go back into the cabin and pull the seat forward. There may be a way to do it without going into the trunk but I havn't looked into it.

 

have the premium so i guess its a no go.. lol

 

Got the 500/1v2 in the mail yesterday and got 'er all hooked up. Sounds much better, with the 250 it sounded like the sub was struggling to get juice a bit. Not any more.

I can hear that the sub wants to move some air, I now believe all of you saying that ported is the way to go with these w7's. I may stop by someplace after work to get the gears turning on a nice ported box. I don't just want a rectangle. I want something cool. I also want to maximize trunk space. We will see...

Also, if anyone wants a JL 250/1v2 practically brand new, let me know. $225 + shipping and its yours.

 

i want a JL but my trunk has no space for it.

 

Thats what I thought too... but the 8w7 only needs a cubic foot. My custom box that I do should only take up the right hand nook in the back of the trunk (i.e. towards the bumper), leaving the rest of the trunk open for business.

 

I just had a 12" JL Powerwedge Max installed this weekend. It fits nicely behind the rear seats.

The Powerwedge max is nice because the 500 watt amp is mounted directly to the back of the sub box.

Now I'm considering replacing all of the factory speakers with JL component speakers.

 

got pics?

 

I havn't made the enclosure yet. It will be my springtime project. Pics of the standard sealed box is in my albums.

 

Ok guys, I've been off getting a custom enclosure built by the best box builder bar none. Check out the thread I posted in the audio section: http://forums.maxima.org/showthread....73#post7477073

 

box looks good sofar i seen the build on caraudio classifields i been along time member there and crazy into caraudio.

 

how did you run the power wires thru the fire wall anymore pics and what did you use for a loc hows the sq on the factory deck im thinking of running two digital designs 10s i have here on 2000w

 

Drilled a hole right next to the factory wire loom thru the wheel well and installed a heavy duty grommet for my my power wire.... as for LOC, I actually used a ReQ sound processor. Def. worth it.

 

New pics: