There's two ways to do this.....

[willwren]

Keep in mind I have a very nice JVC DVD deck in both cars. Other than that, the SLEeper is stock with the dual-voice coils, bass amp and gain control.

The Zilla has JL Audio all the way around (Evolution TR series front and rear), which ditched my dual-voice bass. I built a box for the trunk that held the originals (and still allowed access to my passthru), and re-gained some of my lost bass through the factory bass amp and gain control.


Now:

Looking at a single 10" sub to improve my bass AND control over it. The factory sub setup just isn't cutting it buried in the trunk like it is. Here's the sub and amp:



Remember I said there's two ways to do it? Because BOTH cars have the bass gain control, I like to keep them as similar as possible (both run the same JVC Deck as well). I can either run the output of the factory amp to the input of the JL Audio amp to retain the bass gain control (isolated of course, and the wires are already in the trunk), or I can ditch it, do some interior 'body work' on the old slider slot in the dash, and place the JL Audio gain control knob in the same location.

My installer likes one way (I'll actually do the whole install in all likelyhood), but the owner of the store likes the other way.

Pro's and con's?

[J Wikoff]

I really liked keeping the slider when I did mine. Different sources (radio, CD, different songs) had different bass levels. The slider provided super easy adjustment. When grandma was in the backseat, slider down. When fraternity pledges were in the backseat, slider up.

Keeping the stock slider was super simple. Factory wiring for woofers went into HI-IN on the sub amp.

[willwren]

I've re-wired my slider/factory amp to work with both JVC decks in the cars, but keep in mind the other option is to also have the bass gain, but by using the JL Audio supplied gain control KNOB.

Both options have the same basic result, they just do it in different ways.

[J Wikoff]

I don't see any disadvantage to keeping the stock slider. It should be less work, too.

[willwren]

You or anyone else see any issues using the factory amp's output for the JL Audio amp's input rather than the sub out from my JVC deck?

[J Wikoff]

I do not. The power levels of the stock amp seem to be fine for input into another amp. I don't get any extra noise. I cannot attest to any distortion differences there might be with your headunit/stock amp combo, though. However, mine sounds pretty clean with the stock HU and amp going into the bigger amps.

[willwren]

What I LIKE about doing it that way is that the stock amp samples all 4 channels and determines sub level based on the volume/balance/fade of the 4 channels.

Then I can adjust the JL Audio amp's gain to get me back in the 'range' of the slider that I prefer. As I adjust deck volume, the factory bass amp adjusts itself normally, and sends that as the input to the JL Audio amp.

[Bugsi]

Question: What is the JL Audio knob-based volume control? Can you check it out electrically to see if it's just a glorified dual potentiometer? Because if that's all it is, you could easily put a sliding one from either Mouser or Digikey in the location where the stock bass slider is. -And also, is the stock bass slider anything more than a glorified dual potentiometer too? (Is there other circuitry with it, etc.)

-I really like the idea of keeping the stock slider and taking the stock amp's outputs into the JL amp Hi inputs. One big advantage I see here is that it's all already there and connected, so you could simply *just try it* once you have the JL woofer and amp. If you don't find anything objectionable with it hooked up that way, then I don't see any reason to mess with it any more than that. -It has the possibility to work great without any extra effort, so I say give that a try *first*.

Then if you have some spare time and want to experiment, you can do your thing with the JVC's sub out to the slider and try that too. I don't have the slider at all, so I take all separate outputs from my head unit to separate amp channels. RF, LF, RR, LR go to a 4-channel amp to drive the doors and 6x9's in the rear deck. Head unit's Sub out L & R drives a bridged 2-channel amp to a JL 10" in the trunk. All my controls are with the head unit. The head unit's Sub out tracks the volume up/down knob. Bass level adjustments are on the head unit. You've got much better flexibility with that bass slider. If I had one, I'd use it. As it is, I have to go through a "menu" system to select bass and then use up/down buttons to adjust it. (That's a big pile of suck compared to grabbing a slider and dragging it left or right.)

Also experiment with placement of the 10" sub cabinet when you get it. Your shop recommended placing the back of it against the seatback, firing to the rear of the car, letting the bounce return through the pass-through. (where either of your 6x9's are mounted in your photo in this post.) The physics of this should produce a 3dB gain -vs- firing forward through the pass-through. But physics be *dang*, mine sounds louder and tighter when mounted right in the pass-through firing forward. Actually mounting the *dang* thing so it stays right there has been challenging. I'm using mini eyebolts screwed into the sub cabinet and bungee cords, and it still slops around. If you come up with a good mounting solution, I want to steal the idea from you!

[willwren]

The box fits to one side or the other of the passthru without blocking it. It'll be firing toward the taillights.

The JL Audio gain control is a phone-style connection (RJ), and there's a small circuit board attached to the knob. Not a traditional pot or rheostat as far as I know. Bordering on proprietary. It modifies the gain directly to the amp. The cool thing is that it has an 18' cable and will work WITH the original Delco slider. So I can use the JL Audio gain control to get me in the right 'range' for my stock slider to sound right, then tuck the JL away out of sight.

If it doesn't sound like I want, it's a simple matter of running RCA cables from the back of the deck to the trunk. Simple enough to do BOTH and compare them.

Mark, wiring in the factory bass amp and slider is pretty easy. It would give you the flexibility. The only downside is if you want the thing to look right, you'll change your dash surround, and then you'll have another cutout for the HUD controls. Kinda out of sight, but still there. I tucked my boost gauge in that spot on the SLEeper.

[J Wikoff]

Wasn't there a dash bezel for non-hud cars with the slider/Bose label?

[willwren]

Could be. I've never really looked for 'em. I've always been after the earlier ones that had the slider and the HUD.

[willwren]

I also have the column-shifter with no center console, so I might be out of luck with regard to adding a bass slider.

The box fits to one side or the other of the passthru without blocking it. It'll be firing toward the taillights.

That positioning agrees with the best advice. But try it firing through the passthru anyway, and see if it sounds better/worse/same. I'm definitely looking for comparisons. I may re-try mine like you just described. If you use any system to keep it there (straps, bungees, what-have-you), let me know if you find something that works well. In your cars you might have to worry about the sub box launching to the rear under hard acceleration!

[willwren]

Mark, you'd laugh if you saw how my current box is held. Two bungees holding it at the top. It holds, but it's not heavy. In the new setup, I want the amp attached to the box. All connections will be quick disconnect for a fast 15-second removal. It may not happen on the initial install, but most definitely soon afterwards at least. Firing through the passthru may be something I TRY, but it's not practical to run that way with Dex in and out of the back seat 5 times a week at least. I don't even like to leave the armrest/storage down, much less the passthru door. Besides, Hua told me absolutely run it facing the rear and the passthru open or closed won't matter at all. Firing to the rear distributes the sound/waves better, especially when running a single sub like this.

Still hashing out the details, I haven't made my appointment yet. I'm actually not paying for this setup. It was just bought and paid for as a surprise for my birthday. Now keep in mind that I also write and host the website for the shop, and he's been giving me great discounts on stuff for some time now. I know he's cutting himself to cost or below, so I've tried to never let them install it. That's just more time and/or money out of their pockets.

I just sat down for the first time and priced out all my components in the ZiLLA alone, and hit $1270 for the best pricing I could find (not eBay). That doesn't count the matching head unit in the SLEeper.

So far, I've paid only $400 out of pocket for well over $1500 in components. It's a tough pill to swallow. I don't think my web hosting is worth that.

[Bugsi]

What a great deal. For what it's worth, I'm very happy with the work they did on my window tint and with the pricing they gave me on my JL sub and box. I might not have ever got a sub box if it wasn't for the nice club discount price they gave me on it. Very pleased with that!

I'm right there with you on quick disconnects. I'm not using them right now, but I'm wanting to add them. I want to make sure that whatever connector I use coming off the amp to the speaker has the contacts of its connector protected. Touching the amp's speaker out + and - poles together while the amp is on (unlikely, but nevertheless possible) is the quickest way to blow an amplifier. Most amps don't have good shorted-output protection (many have NONE) and will blow under an output short condition in literally a fraction of a second. I'm looking at the "Speakon" brand of quick-disconnect connectors. Take a look at them. They sell them online at PartsExpress.com, but your shop may also be able to get them. They're kind of bulky, but I think they may be the best connector for the job.

I hear you about the passthru and Dex. I actually leave my passthru closed. I used to leave it open, but I caught my kids poking the speaker, and that's just not acceptable! I too, am using bungee cords, to try to keep the sub box positioned in the center just behind the passthru opening. (With the sub held in place by bungees, it's easy to unbungee and move it to the side if I need to load a long 2x4 or something through the passthru.

My amps are mounted to amp-boards that I cut to fit the shape to the sides of the passthru. I cut them from 1/4" plywood, painted them black, then contact-cemented a layer of automotive carpeting over them, and bolted them to the frame behind the seatback. I have two amps, the 4-channel Alpine on the passenger side of the passthru, and a 2-channel bridged Alpine amp for the sub on the driver side of the passthru. The amps and amp-boards are flush to the back of the seatback, so I can positiong the sub box on either side or in the middle. But I think I need to use stronger bungees, as my sub box still slides from side to side.

[willwren]

Put velcro on the bottom of the box. It works great. Just the hook side.

My amp will be mounted (hopefully) to the box so I can pull the weight out in one easy package for trips/loads/track.

Don't you have a grille on the sub? Wait on your disconnects, and I'll show you what I end up with. The hot leads will all be protected, even if I have to buy a dummy plug to protect them when the box is out.

Whether my sub comes with a grille or not, I'll be fabricating something up, and maybe even if it does already. I USE my trunk regularly. I'm also looking forward to coming up with some kind of unique retention for this setup. I need it in the trunk before I can start planning though.

[lewis26]

Speakon is a PA connector used in middle-upper level speakers. Very robust and can handle tons of wattage. We have a set of dual 18 subs with somewhere around 3000 watts going to each.

Speakon is usually used with large gauge wiring. Even a 1/4" TRS connector, or even a set of bananajacks.


One idea is to mount a dummy set of input jacks somewhere in the trunk so you can just plug whatever in there when the sub isnt in. That way the cables won't be sliding around every which way.

[willwren]

I'm not worried about the outputs to the speakers, the amp won't be in the car either. I'm worried about the high-current power feed. I have a line on a few different options.

[Bugsi]

Great tips, guys, I look forward to seeing what you come up with!

With the amp mounted to the speaker, quick disconnect will entail disconnecting RCA inputs, power lead, ground lead, remote turn on lead, and speaker outputs. If Speakon is really rated so high, you might even use it for amp power connections. Another thought that comes to mind is to rig up an AC power socket and plug, you could connect all three connectors: Power, Ground, and remote turn-on. Just don't ever plug it into an outlet!!!

[willwren]

No need to disconnect the speakers/amp outputs. The amp and speaker comes out together.

I only need to unplug two RCA's and a 3-wire connector for power, ground, remote. That's what I'm after. A single 3wire connector. I might settle for a large 2-wire and a small single, but as simple as possible is best.

[dpcookson]

You are going to need a significant size connector for the pos. and grnd. connections to the amp, ones that can handle high amperage (at the very least 8 gauge wire), maybe a quick connect like the 4X4 guys use on their winch setups would work well for you. The remote wire needs only to be a simple 16 gauge wire and you can just use a common shielded connector such as a male/female spade.

However I am confused about the RCA's. I was undestanding you wanted to keep the stock slider bar and amp setup going to the subs. For this to work you are going to have speaker wire connections to make from the car to the amp instead of RCA connections, so you will also need a four wire male/female connector.