Box chevy build.. disappointment

[sxpimpin 10+ year member]

Well I picked up a 1986 pontiac parisienne recently from my great grandmother and decided I would do a little sound in it. I picked up my old memphis mojo 2000d amp for power and decided to run 6 hifonics HFI 12's. I did 2 layers of deadener on the lid and a layer on all walls of the trunk.

Long story short I've tried subs up port back... LOUD outside, but no bass in cabin.. seriously sounds like a pair of 10s(with alot of flex).. I then tried a small 4th order bp to get the bass firing forward. A tad bit louder but still at least 10db's quieter than I expected. So now im trying to figure out what i need to do. Sale the subs and do something where i can fire subs and port back.. seal around the port completely into the cabin.. ect

I just need some help on the system design.. my HD3 15 on 1200 watts would dominate this setup right now..

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[Slo_Ride 5,000+ posts]

Well a first 1986 Pontiac is not a box Chevy. Second you need to give us a little more info; cubic feet of box, tuning frequency, port area, etc. Have you double checked your wiring to make sure your imp load is correct? I wouldnt expect miracles from the Hifonics HFI subs, it doesnt get much cheaper than that. But with six 12"s there should be more output than "two 10s".

 

[sxpimpin 10+ year member]

Parisienne and Caprice = same car different badging. It's identical to a caprice.

Box was 10 cuft with 90 inches of port firing back tuned at 35 hz. My wiring is fine. I'm really looking for input from people who have actually dealt with caprices, parisiennes, ect

 

[RAM_Designs 5,000+ posts]

10ft^3 net for 6 hifi's? That's cutting it kinda small. Do you have enough room around the box for the air to get into the cabin, or is it stuffed so tight the box itself blocks off air flow?

Is there a specific frequency range where you feel like you're lacking output, or is it pretty consistent across the whole range?

 

[branham1127 10+ year member]

Parisienne and Caprice = same car different badging. It's identical to a caprice.
Box was 10 cuft with 90 inches of port firing back tuned at 35 hz. My wiring is fine. I'm really looking for input from people who have actually dealt with caprices, parisiennes, ect

I'm not familiar with the vehicle, but sounds like you need some more port area... 10 feet of box should have 120-160 sq inches of port to perform nicely for a daily driver.

 

[branham1127 10+ year member]

10ft^3 net for 6 hifi's? That's cutting it kinda small. Do you have enough room around the box for the air to get into the cabin, or is it stuffed so tight the box itself blocks off air flow?

Hifonics recommends 1.75-2.5 ft for each of these subs ..So 1.66 isn't all that small, but still smaller than it should be. I think increasing your port area would help quite a bit, but getting more box space in there would definitely be a good idea if you could. I didn't think about the second part of what Ryan said though, make sure there's room for the bass to travel. If not, take two of them out and make the box 8ft and tune it to 35 hz with 96-128 inches of port. You'll be much happier with 4 of them in a proper enclosure than you will with 6 of them in a not so optimal enclosure.

 

[Slo_Ride 5,000+ posts]

well considering Ive owned several caprices and a tan parisienne I know that a pontiac is not a chevy. also I've owned the HFI's. But I'm sure that you know more than I do so I'll leave it with you. You can look for people who own the same car but if your install is crap then thats your problem. Your box is to small you need 15 cubes and you dont have enough port area. Good luck I'm sure you will fiqure it out.

 

[sxpimpin 10+ year member]

well considering Ive owned several caprices and a tan parisienne I know that a pontiac is not a chevy. also I've owned the HFI's. But I'm sure that you know more than I do so I'll leave it with you. You can look for people who own the same car but if your install is crap then thats your problem. Your box is to small you need 15 cubes and you dont have enough port area. Good luck I'm sure you will fiqure it out.

Not trying to make this a knowledge war man, I just want advise. What would you recommend? Less subs but better? a bandpass sealed firing in the cabin, or does firing a ported box back along with subs that much louder than up firing?

 

[twistedchild420 5,000+ posts]

Wall that bish

 

[ltr450racer690 10+ year member]

x2

 

[RAM_Designs 5,000+ posts]

make sure there's room for the bass to travel. If not, take two of them out and make the box 8ft and tune it to 35 hz with 96-128 inches of port. You'll be much happier with 4 of them in a proper enclosure than you will with 6 of them in a not so optimal enclosure.

This, and don't fire them up this time. Try everything forward or everything back at first, which you can obviously do with the same box.

 

[tez4life Premium Member]

This, and don't fire them up this time. Try everything forward or everything back at first, which you can obviously do with the same box.

x2, honestly, I feel you would be better off with 4 with a good size box, trying to cram 6 in there is why your lacking in output. Even though it hasnt be mention, have you considered cutting out your rear deck?

I know you said you tried a 4th order, but those can be very tricking unless their design correctly. Good luck.

 

[sxpimpin 10+ year member]

The problem with everything forward or back is that the height is only 12.5inches at the rear and only 45.5 wide...

I think im going to do a complete rebuild soon enough //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[mclerico83 5,000+ posts]

4 subs in a w shaped box with the port firing up through the rear deck you will have plenty of room

 

[sxpimpin 10+ year member]

hmm i think i see what your saying