Hi folks,

Wanted to consult the experts to make sure I'm going to get the wiring set up correctly. I am on a tight budget and am hobbling together a bunch of equipment I already have for a "budget" build. From the graphs below, I already have the amps, the rear 6 x 9s, the 12" sub and box, and I recently got the MB Quarts as a gift (per Vince's "recommendation" in this post, but I realized he moved on to Kenwood Excelons more recently -- Vince, hope I didn't goof by putting those MB Quarts on the wishlist!).

Anywhoo, it's been a while since the EE courses in college, so I wanted to confirm my wiring notions. I created two different pictorials to illustrate basically the same thing, but the question is:

On my Kicker IX1000.5 sub output (500W x 1 @ 2 ohms and 250 x 1 @ 4 ohms RMS), if I run two separate sets of wires from the Sub-out on the amp to the MB Quarts in the doors, each sub will be getting 250 W RMS since they'd be wired in parallel and constitute a 2-ohm load -- correct?

(And I'm assuming the same thing would happen for wiring the Infinity 3.5" door speakers and Infinity tweeters in parallel in the same fashion -- 65W RMS would be sent to each?)



Here is my overall potential setup. I'd love to know any pitfalls I might experience, so please fire away! Also, I might eventually replace that middle 3.5" speaker with an Infinity unit, but I read in other threads that it doesn't really make much of a difference, so I figured my limited money would be better spent elsewhere.

 

@VinceC5 is the guy to talk to about the C7’s, he’s currently in the process of doing his C7 right now, plus he knows a lot of stuff about car audio systems. His thread on his build. https://www.corvetteforum.com/forums...ert-build.html

 

1. The MB Quarts are dual 4 ohm, so you will be seeing a 1 ohm load, which will not work with the amp.
2. I ran mine in "stereo" as a midbass driver. The door cavity is to big and the woofer will make a popping sound with anything under 60 hz at high volume. I never tried running them mono.
3. I switched to the Kenwood because I saw that they could play up to 850hz where the MB could only go to 250hz. 60 - 850 is his I run them.
4. Insane amount of dynamat is required all over the doors.
5. 6 X 9 won't fit and are not worth the trouble of hacking up of the car to get them to fit. If they are sentimental, put them on the shelf so you can look at them everyday.
6. Disconnect the center speaker.
7. Disconnect your door microphones. You can do this at the door panel or at the factory amp.

Do you have all the amps already? If not, get rid of the Pioneer and go with a good size two channel. Run the 2 channel to the door woofers and the 5 channel to the rest of the system.

good luck on your build.

 

Atta boy Vince, I knew you’d come through.

 

1. The MB Quarts are dual 4 ohm, so you will be seeing a 1 ohm load, which will not work with the amp.
   1. damnit you're right. That totally skipped my mind. My current single sub plugged into that amp is a DVC, so that makes sense with the 500Wx1 @ 2 ohms. I guess if I'm outta luck with the MB Quarts (possibly out of the return window at this point), I could do this?
      1. Series-Parallel Wiring (4 ohms):
         1. Wire each voice coil in series, effectively doubling the impedance of each subwoofer. This means each subwoofer would have an overall impedance of 8 ohms.
         2. Then, wire the two subwoofers in parallel.
         3. This configuration would result in a 4-ohm load, which matches the 250 watts x 1 channel at 4 ohms rating of your amplifier.
         4. Each subwoofer would receive half of the amplifier's power, so they would each receive 125 watts.
2. I ran mine in "stereo" as a midbass driver. The door cavity is to big and the woofer will make a popping sound with anything under 60 hz at high volume. I never tried running them mono.
   1. Good to know. Hopefully I can return the MB Quarts and go back to the drawing board. I'm thinking perhaps putting the 6 x 9s in there instead, per your suggestion in my other thread.
3. I switched to the Kenwood because I saw that they could play up to 850hz where the MB could only go to 250hz. 60 - 850 is his I run them.
   1. $180 a pop is too rich for my blood, currently... But that would be awesome!
4. Insane amount of dynamat is required all over the doors.
   1. Will do! I have a whole box of it (36 sq ft) ready for under the seats, and we'll see what remains for the doors. Worst-case is I get another, smaller box ordered. Rear hatch and behind-the-seats area have already been covered.
5. 6 X 9 won't fit and are not worth the trouble of hacking up of the car to get them to fit. If they are sentimental, put them on the shelf so you can look at them everyday.
   1. You're selling me hard on those speaker boxes. I never thought about putting them in the boxes purely because I could see them. I'm just trying to prevent doing something janky-looking in the car, as I used to have cheaper 6 x 9s in speaker boxes in the past, and they rolled around the hatch area when I'd take turns. (But I understand I'm a big boy now, and can buy better boxes and tie them down so it looks nice.)
6. Disconnect the center speaker.
   1. Oh sweet that's an easy win -- will do!
7. Disconnect your door microphones. You can do this at the door panel or at the factory amp.
   1. Will do x 2! Just out of curiosity, how come?

Do you have all the amps already? If not, get rid of the Pioneer and go with a good size two channel. Run the 2 channel to the door woofers and the 5 channel to the rest of the system.
Yup I already have the amps, subs, 6x9s and possibly some wiring stashed in the garage. I like your idea of getting a 2-channel for the doors, but IIRC the 12" sub in the back is a 4-ohm single-coil design, so I'd only be putting 250W into it through the 5-channel amp. The Pioneer amp and the Kicker 12" were a previous install in one of my sister's cars that she no longer needed, so they were matched up in terms of spec. So then I'd get into replacing the sub as well, and all of a sudden we're a solid $1K more than the "budget" currently allows

good luck on your build.
Thank you! I wholeheartedly appreciate being able to bounce my ideas off of someone, so thank you for taking the time to reply!

 

I still would not run the door woofers as you have them. Running them the you have them means only 200hz and down will go to them. I don't think you'll like that sound.

 

I was able to return the MB Quarts, so that problem is solved (thanks again for catching that, @VinceC5 ). New audio setup below, which is markedly simpler and easier on the budget.

I'd love your assistance for a few questions:

* I'll run both 3" (3.5 ohms nominal) and the 6x9s (4 ohms nominal) through the front 2 channels of the amp. The amp is rated for 65W RMS at 4 ohms and 125W RMS at 2 ohms per channel. Given that I'm running those two pairs of speakers in parallel, will each speaker see ~65 watts, or ~125 watts? I'm getting differing answers depending on where I look things up.

* I'm assuming there's no way to also hook up an aftermarket pair of tweeters in this setup, correct? The amp is only stable to 2 ohms, if that matters. I'm assuming I *could* potentially hook up tweeters to the rear channel that is powering the 6 1/2" rears, but I'd think that would mess up the fade controls...

* I thought the stock speakers in the back are 5 1/4", but looks like lots of 6 1/2" speakers also fit, according to Crutchfield and other sites. Is that correct? The Kappa 62IX should go in without issue? And they appear to be 2.5 ohm nominal impedance, so I assume they'd be seeing more than 65W per speaker?

* I'll get rid of the Pioneer amp as you suggested, and put it in my other car (where I'm taking the Kicker out of). The only downside there is that most likely I'll only get 250W RMS running to that sub, unless somehow it's magically a DVC. I'll need to go dig it out of its box in the garage and verify the model number. Worst come to worst, I can always upgrade it later to a DVC setup, but the thing will be right behind my head, so maybe it'll be fine as-is

Overall, I like this setup way more, since it's only one amp to install, one set of wiring for it, etc. And I think it'll still be a marked improvement over the stock Bose system.

As always, I appreciate your help and any thoughts you may have.

 

Do you already have the Lc6i?
Here's what I would do:
1. Replace the Lc6i with Lc2i (this has the bass restoration) Use the front door woofer signals as the input because it's a full range signal.
2. Run the amp in 3 channel mode (connect to just the 6x9 and sub)
3. Run the rest from the factory amp, including the dash tweeters.
4. Rear speakers are 5 1/4.

if you use the factory wiring, the dash tweeters are connected in parallel to the door woofers, so #3 can be a little tricky. You can get to the patch point in the kickpanels or at the tweeter. If you go to the trouble of getting to the dash tweeter, you might as well upgrade it.

 

I don't have the LC6i, and TBH it was a placeholder for "an AudioControl device." Looking at the LCXi line, a better fit would be the LC7i or the LC7i Pro.
However, I do already have an LC2i Pro in the other car, so I could potentially take that out to at least try this proposed setup, and then buy another one for the old car.

Combo question for your points 2 and 3 above -- how come? Does the amp stability get dicey with my 2nd plan (3" and 6x9s wired in parallel), or is something else driving the recommendation? And relatedly, does the Bose system provide enough wattage for the new Infinitys? Looking at some other threads, it appears it only puts out 23W RMS at 4 ohms / 38W RMS at 2 ohms, which isn't exactly trivial, but definitely not 65W/125W per channel.

And for #4, does that mean 6 1/2s don't fit at all, or might require some adapter/ modification?

Thanks for the heads-up on the tweeters/woofers being connected in parallel. I'll do some digging on how to best solve that problem.

 

When you wire speakers in parallel, they get the same amount of power. That means the 3" will be as loud as your 6x9. You don't really need that much power on a speaker that is almost at ear level. On my system, I have 100W to each set of 3" and tweeter, by only because I have a dedicated amp and dsp that can be adjusted to blend in with the midbass. You can try both ways and leave it however you like it better. Everyone is different.
Again, this is a Corvette not a Chevette that would not matter how much you hack into it... I wouldn't do it for just a normal speaker. If I wanted to put a high end speaker like a Focal Utopia, then yes, probably worth it. But then, you would need a better amp... like building a race car, there are always higher quality, more expensive options.

 

1) Quality over quantity. I would ditch EVERY piece of Bose garbage and run only good quality aftermarket parts to avoid letting the cheap speakers/amps/processors make your image muddy.
2) Take whatever you were going to spend on rear speakers and put that elsewhere in the budget. It will be plenty loud with a good front stage and subwoofer. Music is only recorded in 2 channels, so "rear fill" is just echoes and noise compared to the original master recording.
3) Instead of a generic line out convertor, I would invest in a real DSP like the DM-608. Time aligning the midrange, midbass, and subwoofer will have a HUGE impact on sound quality. Corvettes have a bunch of potential cancelation in the 60-120Hz range when multiple drivers are playing similar frequencies. You really want to fix this if possible. (Use the savings from #2 here!)
4) Other guys said it, I'll repeat. The lower frequency you want to play from the doors, the more important it is to reinforce and sound deaden them. Factory doors are significantly more flimsy than a good home speaker enclosure. Getting good sound requires that the cone is the only thing really moving.
5) A really good set of 6.5" front mids (properly installed) paired with a time aligned subwoofer in the back is really all you need to knock your socks off. I see lots of people over complicate this with mixed results and spending.

 

Thank you both Vince and Greg for the replies. Vince, good note on the speaker being face-level -- will take that into account.

I know there's lots of "but the soundstage!" folks on here, and I appreciate the concern. I think that because I've listened to music on headphones for years, I've developed a taste for equivalent levels of sound coming from the back as from the front, where sometimes the fader was set to -2 Rear bias in some previous cars. That's why I wanted to have the Eclipse 6x9s in the rear originally -- that's where they were in my '98 Accord. See some cool Eclipse pics below

Reading through other threads, I'm noticing some folks recommending a DSP like Greg mentioned, while others the PAC AP4-GM61 -- and others recommending both. I understand Greg's point about fixing the "BOSEification" that occurs with the stock system's audio signals, but would either one do the job? I know I mentioned this was a "budget" build, and a $400 doohickey is not exactly "budget", but either way I was thinking of getting an AudioControl LOC of some kind -- so the PAC isn't too far off. And from what I can muster, I can get the PAC and don't need a DSP or LOC, since that clean signal would go straight into the amp(s).

I'm totally going to Dynamat the snot out of the doors. I already covered the back hatch area and rear firewall behind the seats in butyl / foam liner. Cherry on top was one of the Blockit Deadmats from TKO Performance.

Greg, what do you mean by '6.5" front mids' in the doors? In the lower cavity where the 10" woofers currently reside? I'll be putting the Eclipse 6 x 9s in there

Also, any recommendations on a cheap 2-channel amp to power the 3.5" door mids? I'm seeing this Infinity Primus 6002A unit with decent power for $105. (I'd use the existing Kicker IX1000.5 amp to power the 6 x 9s and the rear speakers.)

And I still can't seem to get a straight answer if these would fit in the back. For whatever reason, both Crutchfield and Sonic Electronix show plenty of 6.5" speakers as eligible for that location. If those do not fit, would something like these https://www.crutchfield.com/p_091RCX130/Focal-RCX-130.html?tp=105 be recommended? Unfortunately the 5.25" Kappa is a solid $80 more, and I'd rather stick to the ~$100 price range if I also have to potentially get the PAC (and another amp) as well.

(I have no idea why the links appear goofy, everything looks normal when I go in to edit the post.)

 

Yes. I only run 6 speakers total in my Corvette. ...and that's only because I have a pair of subs, so it's 5 channels of amplification total. My Morel 6.5" mids are in the factory 10" location with a good stiff adapter plate and sound deadening. I have a set of large format Morel 1" silk domes in the factory 3.5" upper door location. No center channel, no rear speakers and the soundstage is phenomenal after time alignment, individual channel EQ, 24dB crossover slopes, and proper gain matching. There's no frequency that isn't adequately covered by these. Sometimes less is more.

Ironically, even my Kenwood Excelon head unit's "flat" output required some fixing from the DSP that I didn't event realize was in there before. I had always ***-umed that the high end pre-outs would be correct. The DSP's input RTA revealed they were not, and cleaning that up resulted in better sound to my ears in the driver's seat. Throwing a generic LOC on the factory head unit is likely to have similar results.