Touring high power subwoofer replacement

[Superthermal]

Hello forum!

I have taken and exhausted the possibilities to get decent clear base from a woofer in the stock position of our 2016 Honda touring civic sedan. From the factory, the stock subwoofer not only lacked real base but the plastic rear deck cover in the area of the 3rd break light would rattle uncontrollably against the rear window and lower steel deck. I have taken many steps to minimize this vibration and have had great success in removing the horrible noise in this area… HOWEVER due to the sock steel deck being so flimsy… when I say flimsy I mean that when I placed my Kicker 8” CompRT8 400WRMS sub into this and played a bit of bass the entire deck had a deflection of no less than ½”! I thought it was going to rip apart! WHOOOA! I have since coated it with sound deadener which added to the overall mass of the deck and did a good job to minimize this deflection at most frequencies but due to the weakness and flimsiness of the deck it was by no means gone. I then purchased… now don’t laugh a 12 ¾ x 10 3/8”x 4” 24 gauge steam table pan and mounted this on the underside of the woofer to provide a .23 cu/ft sealed enclosure for the sub.(my sub needs .2 to about 1 cu/ft for a sealed box) This “box” provided additional rigidity to the rear deck to minimize deflection but still not surprisingly did not eliminate it. Due to the movement, still present, the rear steel deck deflects causing the attached plastic deck to vibrate even more as if it was a large speaker causing alternate frequencies than what are desired making tones at specific frequency rates. This drives me NUTS!

Additionally to try to control this "woofing" of the rear plastic deck panel I drilled out the plastic welds of the subwoofer plastic speaker grill and removed it. ( I needed to do this also for the Kicker needs more space for its throw than the stock unit and with it removed the speaker face is perfectly placed..) This is a horrible design and has a perforation pass through rate of I'm thinking about 40%. Speakers need 60+. So as the woffer woofs (LOL) the plastic is pressed away from the woofer face due to the air trying to bleed through the plastic grill, the air is then sucked back through causing it to cavitate back and forth. Since removing this the problem is much better but the bigger problem is the speaker being mounted on what is just a little better that a piece of cardboard or is it silly pudy? or is the metal just painted plastic and no one told me?

The only way I can see getting the vibration out of this rear deck is to massively reinforce the steel deck using who knows what. More steel? Angle iron? Bracing between the wheel wells?

I have considered removing the sub entirely from the deck and using a subwoofer enclosure that holds the speaker in the trunk and directs the air movement up through the removed woofers hole. This would remove the weight vibration of the speaker when it is doing its thing so only air/sound would pass through this area. However, this is undesirable due to loosing trunk space which is a priority for me. I can’t stand base that is hidden away in a truck. Muffled and missing its…. Definition. I am beside myself that the steel on this car is so flimsy. My self tapping screws go into this stuff like butter hardly turning a full rotation before sinking in. Wow. If I had considered this is where I would be I would have purchased a 10 or 12” sub and gone for the directed woofer method. Still considering what to do. Anyone else run into this?

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[inv4zn]

Ima just leave this here, since I wrote it.

http://www.civicx.com/threads/cheap-permanent-touring-rattle-fix-insulation-foam.4272/

 

[josby]

Interesting - I had wondered if there was enough room under the sub grill to accommodate the excursion of an upgraded sub. I'm not too surprised to learn there isn't.

How about ditching that spot for a woofer altogether and put two 6.5" woofers (e.g. JL 6W3v4) in place of the 170mm midranges in the rear deck? You'd get slightly more total cone area than with one 8", and less moving mass at each speaker flexing the deck. Plus they'd be over closer to the edges of the deck where there should be less flex than in the center of the deck.

 

[Superthermal]

Thanks Josby for your interest. and you too INV4ZN.


First INV4ZN, After the first day i began looking into fixing the rattle... By day three of having the car I already tried the wedge fix you have posted and it worked well but there was still no serious base and the mid and mid low were lacking to my preference. With the rattle the wedge is forcing the center light and center plastic deck assembly up against the glass of the back window. This is a great fix for the stock sub and I could see others using it with success. In my case though the best fix of this flopping of the plastic deck was slitting a back window wide piece of http://www.homedepot.com/p/M-D-Buil...Rubber-Foam-Weatherstrip-Tape-06635/100353487 weather strip tape slit in the center of the adhesive side about 2/3 deep lengthwise which is pressed onto the entire length of the plastic deck. When the deck is slid back into place it pinches tightly the plastic deck equity between the glass and the lower deck THIS made the biggest difference of all items I tried for just rattle noise. Additionally I removed the 3rd break light and padded under where the hard polycarbonate body of the light meets the softer plastic decking. Also the rear deck has several drop-in tabs that rest the rear edge into the lower steel deck to create a type of pinch point. I padded these as well. Wire vibration control was also needed. All of these steps + sound deadening + sub grill removing has made the plastic deck almost bearable with the aftermarket sub. All of these steps controlled the plastic deck issue vibration against the window and lower steel deck wonderfully, however as I mentioned in the opening tread it is the steel deck that is made out of is just outright flimsy steel that will not stay in one place when any sub with actual power is screwed down to it. This causes the entire assembly (Steel and plastic deck) to vibrate undesirably. So for my application the trusty wedge didn't work.


Onto Josby


I need the mid range speakers in the rear deck due to having many passengers and only two door speakers to cover the rest of the interior would be inadequate for my taste. Thanks for the suggestion and I have started to contemplate cutting the entire deck out and placing a new steel piece in place with a custom speaker layout but... not there yet. I think it would be very hard with pretend massive speaker perforation areas in the plastic deck to make it look nice.

With the speakers ... Well The 6.75" replacement speakers 2 of Rockford Fosgate P1675 Punch 6.75-Inch 3-Way Coaxial Full-Range Speaker I purchased for the doors and the rear deck just barely "fit" into the rear deck with a little modification (bending of the sheet metal) to allow the lower cage of the speaker to drop in and drilling new screw holes. The doors needed adapters American International Honda Speaker Adapter Kit - HSB524 + a little cutting near the tab clips. The factory head unit is driving the amps through speaker level inputs. The 6.75s are capable of doing most mid to low mid frequencies but the stock EQ for those door and deck speakers is taking a good chunk out of the mid frequencies and more of the lower mid frequencies out and has only about 5% (i am guessing leakage of their circuit) pass of anything that even is close to 250 HZ. So if I went that route I would have what I would see as insignificant base but would need to purchase first an AudioControl LC7i to be able to mix the base sub woofer channel back into the door and deck channels and then use my amps Rockford R300X4 Prime 4-Channel Amplifier adjustable cross over to keep the deeper HZ out of the 6.75s so they dont... melt? LOL. I am considering jumping over the LC7i for the DQ-61 so i can have some eq control as well seeing the huge holes in the factory eq. It is sad that no one has been able to talk the Honda guys to have a pass code where you can go to a dealership and have them remove the EQ'ing of the factory head unit. Oh wouldn't that be nice!!! OW. Not going to happen I think.


I am going to try a box hung below the rear deck to mount the sub in. I should have it in and tested Monday or Tuesday.

Thanks for the input. Anyone have any other ideas? or used the LC7i in the Touring Civic? or the DQ-61?

 

[josby]

I need the mid range speakers in the rear deck due to having many passengers and only two door speakers to cover the rest of the interior would be inadequate for my taste.

Yeah, that's understandable. I was actually looking at the door panels from the new Civic hatchback:



...wondering if it'd be possible to put them into the sedan to add some rear door speakers, but it looks like the hatchback rear doors are a slightly different shape so it wouldn't fit.

Other ideas: Have you considered an underseat sub (e.g. JBL BassPro SL)? I don't know if there's room under the seat for that or not though.

Or maybe take the tool holder thing out from inside the spare tire and fiberglass a sub enclosure into the area inside the spare? You'd have to relocate the jack and tire iron somewhere, but they're pretty small. I bet you could fashion something to hang them up under the rear deck in the area where the factory sub was.

Or, how often do you need both rear seat passengers AND the full trunk space at the same time? If it's not too often, you could put a small sealed box in the trunk and make the wires from your amp long enough that you could relocate the sub to the back seat whenever you need full trunk space.

Thanks for the suggestion and I have started to contemplate cutting the entire deck out and placing a new steel piece in place with a custom speaker layout but... not there yet. I think it would be very hard with pretend massive speaker perforation areas in the plastic deck to make it look nice.

Yeah, if you do that, I think you'd be better off making your own new rear deck cover out of MDF, grill cloth, and vinyl wrap. But ugh, I wouldn't envy you that task.

The 6.75" replacement speakers 2 of Rockford Fosgate P1675 Punch 6.75-Inch 3-Way Coaxial Full-Range Speaker I purchased for the doors and the rear deck

Out of curiosity, why did you put 3-way coaxes in your doors, instead of doing a traditional midrange and then replacing the tweeter in the sail panel?

would need to purchase first an AudioControl LC7i to be able to mix the base sub woofer channel back into the door and deck channels

Unfortunately I don't think it would do that. Look at the block diagram for the LC7i:


It appears the AccuBass only affects the subwoofer output.

It is sad that no one has been able to talk the Honda guys to have a pass code where you can go to a dealership and have them remove the EQ'ing of the factory head unit. Oh wouldn't that be nice!!! OW. Not going to happen I think.

Yeah, I don't think that will happen. It's annoying that older Honda head units had a "flat" mode you could enable, then it seemed they switched to having that but the setting wouldn't hold after you turned the car off, and now here we are with our car not having a setting like that at all for us.

 

[Superthermal]

Yeah, that's understandable. I was actually looking at the door panels from the new Civic hatchback:



...wondering if it'd be possible to put them into the sedan to add some rear door speakers, but it looks like the hatchback rear doors are a slightly different shape so it wouldn't fit.

Other ideas: Have you considered an underseat sub (e.g. JBL BassPro SL)? I don't know if there's room under the seat for that or not though.
I have the powered seats, My wife is 5'2" and Im 5'10" so we move the seat around a bit. I haven't looked into this deeply. The JBL is an option but lacks some power for the price $249.. hmmm I would need to hear one in person first.

Or maybe take the tool holder thing out from inside the spare tire and fiberglass a sub enclosure into the area inside the spare? You'd have to relocate the jack and tire iron somewhere, but they're pretty small. I bet you could fashion something to hang them up under the rear deck in the area where the factory sub was.

We have the spill pan in the trunk and so everything will need to stay up top.


Or, how often do you need both rear seat passengers AND the full trunk space at the same time? If it's not too often, you could put a small sealed box in the trunk and make the wires from your amp long enough that you could relocate the sub to the back seat whenever you need full trunk space.

My babe-OOOOO-lishous wife and I have 6 kids so we do lots of store runs etc... with passengers and hauling food.



Yeah, if you do that, I think you'd be better off making your own new rear deck cover out of MDF, grill cloth, and vinyl wrap. But ugh, I wouldn't envy you that task.

Yes, no envy there. Removing the rear window for the weekend/week and putting in whatever I dreamed up would be more than I think I can do.



Out of curiosity, why did you put 3-way coaxes in your doors, instead of doing a traditional midrange and then replacing the tweeter in the sail panel?

1. I was trying to keep below a budget total price for the amps and speakers.
2. I expected to just detach the tweeter in the sail panel knowing it is a cheep unit but ended up keeping them connected for now.
3. I looked at a lot of other quality speakers but compromised on these due to the cone type (sound type) that I prefer.
4. I knew they had way better sound than anything that was going to come out of the stock speakers. After break-in doing some sweeps (frequency sweeps) they play very nice and plenty loud to damage anyone's hearing. Way clear.
5. I was also trying to match the power output to the amp I had settled on as well.
6. As a bonus they would take care of anything down to the 60hz (speck of range) if needed with the power the amp would be sending. (I would never send anything that low to them... but down to 90 or so they should play hard.)


Unfortunately I don't think it would do that. Look at the block diagram for the LC7i:


It appears the AccuBass only affects the subwoofer output.

Dang!!!!!!!!!!! I am so glad you pointed that out. I had only watched the videos on how well the Accubase worked.... bummer 4me. I guess at best with the mixing of the signals at least the LC7I would give back some of the mid and mid-low even if it disappears as the volume increases. Have you seen anything around here in the talk on just how much the head unit is quenching the mid-lows and base in relation to the volume? How much does it roll off? I haven't measured this and it is annoying thinking they did this without having a setting to shut it off.



Yeah, I don't think that will happen. It's annoying that older Honda head units had a "flat" mode you could enable, then it seemed they switched to having that but the setting wouldn't hold after you turned the car off, and now here we are with our car not having a setting like that at all for us.

Ill Let you know how the little box turns out. Hope I like it. So this can be over because if it doesn't I will be over-killing on any solution to fix it.

 

[Superthermal]

I guess I need to learn how to parce out your post so my responses look like yours... It this the insert bookmarks function?

 

[StarCreator]

I guess I need to learn how to parce out your post so my responses look like yours... It this the insert bookmarks function?

I don't think so. I would just copy and paste the "QUOTE" start and end tags as needed to split up the post you are replying to.

 

[Superthermal]

In re-visiting the LC7i. I see at second look the Accubase leveling on the subwoofer circuit happens before the summing circuit. This would seem to me that the base re-leveling would be for all speakers. This is followed by the base knob adjustment by the user. But on the DQ-61 the summing circuit is before the Accubase circuit so as to think the Accubase only affects the sub circuit and then the final base knob adjustment by the user. This would leave out any intelligent re-leveling of the mid-low and low frequencies in the front and rear deck speakers. I will call and talk to one or more of the three local Accubase dealers in my town about it so I get what I am looking for. All channels filled with all frequencies so I can use my amps to tune what is best for the final speaker sound and performance. Thanks again Josby for helping me not miss something.

 

[Superthermal]

In speaking with a local distributor the Accubase circuit is centered around 60Hz. From his description for my system (and others like it) there is no benefit to having the Accubase circuit before or after the summing in that unless your speaker can play 60Hz you will never notice any "restoration" of the base as the volume goes up or down in the non sub speakers. So summing all channels before or after the Accubase circuit isn't going to make any diff unless those circuits will be running sub frequencies around 60hz which in my case is not likely at all. So using the LC7i or the DQ-61 are a as same same except for the additional EQ capabilities that are added in the DQ-61.

 

[Superthermal]

Added the box Single Car Truck Wedge Black Subwoofer Box Sealed Enclosure for 8-Inch Woofer 8F (from AMAZON) under the rear deck mounted with metal strapping (temp install) to verify the concept and so far I am smiling. The base is without question stronger and tighter and better ranged without the issues with the rattling deck. I was not able to place the box with the 8" woofer exactly aligned under the stock location but it is within an inch and a half. I am considering relocating the trunk key RF? sensor from the rear seat pillar to gain another 3/4" of alignment but so far I am not thinking it will be needed for performance enhancement. The Square 10" Q-series grill from Kicker will show up soon and then I will mount everything permanently. The only drawback in this is that if I had known that I could not use the original deck sub location and I would end up placing the speaker under the deck I would have purchased a 12" small box speaker to take its place and had a better low end and punch on base that just simply requires a large movement of air to reproduce. However maybe this isn't so bad due to the car if purchasing a 12 or dual 12's would need so much sound dampening I could go broke or I would never be done rattle hunting after each drive! LOL win and loose I guess.

 

[josby]

Cool! Post some pics!

 

[Superthermal]

Here is a pic of the back deck before giving up on vibration. The removal of the "Clogged" speaker grill was quick and as stated before will be replaced by a Kicker Q-series 10" grill. When it comes in (3-4 week order time apparently) I ll mount it up and post some picks.

 

[Superthermal]

Follow up. Running with the 8" in the trunk hanging with the straps I was still getting some vibration from the plastic deck at times (not very much, but enough). Tried moving the sub to lay on the trunk floor in various positions and it definitely reduces the amount of harmonics created by the back deck vibrating. Just a cleaner sound. However having the sub in the trunk does muddy the clear base which I was shooting for by using the deck location to start with. However I will take muddy base over rattle any day. I guess just having the sub even close (Straps were hanging from the deck) to the deck is just a bad idea anywhere if you dont want to hear the deck vibrating it's jelly like metal structure. At this time I have the sub facing upward from the corner of the drivers side and it is decent. Still regretting not having a pair of 12s however with a set of powerful 12s I would need to protect the 6 3/4 speakers in the deck from the pressure created in the trunk space. I have seen some baskets/baffles that look like they could do the job.

For now I am going to leave the system as is. If I decide to change up anything I will be looking for some 12s running 1200watts in a box about 36 x 15.5 x 11.5 deep.

 

[Superthermal]

OK, an update on the sub setup, trying out a Rockford Fosgate P1-2x12 500rms @ 2 Ohm setup. MMMMMUUUUCCCCHHHH increased base over the 8" CompRT. Base is way overpowering the front speakers for sure.(Feels as much as it sounds I think). Subs are facing the trunk. Tried it vertical thinking maybe the port facing the hole in the rear deck may let a bit more base enter the cabin but it only fired up that crappy deck rattle I cant stand the base was reduced. I placed my hand over the open spot in the deck where the old sub was mounted and surprisingly there was very little air movement. This was with the port facing the hole. Hmm interesting. Anyway I like the rear facing anyway and it seems at this power level the deck speakers are not in danger at this time.
The CompRT was wired at 4Ohms so it was pushing less rms, about the range of 335, but the 2 ohm box from RF can take the 575 that the amp was tested at. However I am loosing a lot of rms due to voltage drop which I had not noticed with the CompRT. Ill measure it later when I get more serious about matching the sub to the amp since the box isn't even broken in. Anyway I am seeing the light for the beauty mirror dimming when the sub hits even at "reasonable" volume levels when at idle which disturbs me. I'm thinking a 2Farad cap is going to be needed. Little hard to tell how bad it is without breaking out my meter.
By the way the size of this box for the dual 12 P1, P2 or P3 just barely fits into the trunk. Took a pick to show how close it is if anyone out there is considering to build their own box I would say 1 inch max larger or so if you dare. Seems to fit well once in place. Ill post the pic later.

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