Jump to content
Second Skin Audio

18 sierra crew box help with port area and direction


YukonXL04

Recommended Posts

Hey guys so I currently have 2 f8l ported on my DD m2a. Never really liked how my box turned out so I will be building a new box to hold 3 of them.

Current box is 1.4 net with a 3.75x6 slot port. Sounds really good and slams for 2 8s. Subs are forward fire and port is out the drives side.

 

New box will have 3 on the face and thinking about a flared 6" aero where a "4th" sub would be to create a uniform look across the front baffle.

 

Questions:

1. Is a flared 6" enough port area for the 3 8s. Seems like alot for a 2 cube net box.

2. Should I say screw looks and run the port out the drivers side like it is now? It would be easier but probably wouldn't look as good.

 

I have roughly 3 cubes gross to work with. After the 6" flared port, sub displacement, bracing and other deductions I should be right around 2 cubes net @34hz and running at .67 on my DD m2a around 2k rms.

 

What do yall think?

I will attach pics of my existing box, the big hole was a storage cubby for tie downs and such. Wont be there on the new box

Id1FiMf.jpg

0PPyFUG.jpg

iDxdov6.jpg

Hhu2Wpj.jpg

18 Sierra 6.2 Z71 : 3 F8L's, DD M2a @.67, 1.95@33

05 TL build log SOLD

04 YukonXL : jvc kw-v51bt , RE 6.5c, 4 jbl gt5 12s, Memphis pr1000.1 5.5 cu.ft. sealed

Link to comment
Share on other sites

This is what I built for my silverado, my port is side firing on the driver's side, driver is down firing on passenger side. The bass is night and day better in the driver's seat compared to front passenger. Do you not have that problem with your current box? I'm typically the only one in the vehicle, at least my seat's the better sounding one. It sounds great on both sides but the driver's side sounds amazing. When I upgrade trucks again, I won't be doing a side port.

 

http://www.southpad.com/silverado

 

 

Link to comment
Share on other sites

7 hours ago, CorNut said:

This is what I built for my silverado, my port is side firing on the driver's side, driver is down firing on passenger side. The bass is night and day better in the driver's seat compared to front passenger. Do you not have that problem with your current box? I'm typically the only one in the vehicle, at least my seat's the better sounding one. It sounds great on both sides but the driver's side sounds amazing. When I upgrade trucks again, I won't be doing a side port.

 

http://www.southpad.com/silverado

 

 

Yea I saw yours on the other page.

Honestly I dont know what it sounds like on the passenger side. But I know everyone who has been in my truck has been extremely impressed. So must not be bad on the passenger side.

 

Triticums calculator says I need between 34sq in to 52 sq in. At 52 for a 34hz tune the port is stupid long like 52" long LOL

18 Sierra 6.2 Z71 : 3 F8L's, DD M2a @.67, 1.95@33

05 TL build log SOLD

04 YukonXL : jvc kw-v51bt , RE 6.5c, 4 jbl gt5 12s, Memphis pr1000.1 5.5 cu.ft. sealed

Link to comment
Share on other sites

5 hours ago, YukonXL04 said:

Yea I saw yours on the other page.

Honestly I dont know what it sounds like on the passenger side. But I know everyone who has been in my truck has been extremely impressed. So must not be bad on the passenger side.

 

Triticums calculator says I need between 34sq in to 52 sq in. At 52 for a 34hz tune the port is stupid long like 52" long LOL

It's hard working with small boxes. My port is too small, it was a compromise between port size and net volume. In hindsight, that might be part of my problem since I was too stubborn to raise my backseat on a (at the time) brand new truck. People that ride in my passenger seat are blown away as well, the box itself looks like a bench for the backseat unless you know what you're looking for, it catches people by surprise. Certain notes do get vent noise, I'm ok with it but I'll do things better next time. I'm thinking when I get a new truck, I'll go forward facing port if it has adequate port area, if not I'll try to do a rear facing slot port in a nonrestrictive way if it's possible. It's hard doing under seat boxes unless you go sealed but that's limited in its own ways. 

Link to comment
Share on other sites

  • 1 month later...

So here's how my box turned out. I wanted it to follow the seat better, but needed the build it how it is for airspace requirements.

I did build and install a 2" seat lift btw.

 

I ended up at 1.95 net at 33hz with a 6" port. Could only flare the outside though 

Wired at .67 on the M2a

 

I still need to make the pressed grilles to cover the subs though.

 

mjl0uNM.jpg

VJ4yUQp.jpg

2K6zjsL.jpg

qAJEGUv.jpg

 

18 Sierra 6.2 Z71 : 3 F8L's, DD M2a @.67, 1.95@33

05 TL build log SOLD

04 YukonXL : jvc kw-v51bt , RE 6.5c, 4 jbl gt5 12s, Memphis pr1000.1 5.5 cu.ft. sealed

Link to comment
Share on other sites

11 hours ago, Scotnemily said:

That turned out looking really nice. How does it sound now?

Oh it bangs. Shocking for 8s. But now it's time to upgrade the alt and add a second battery. Having voltage problems at .67 so I have just been running it half volume or so. 

 

I built a seat lift for a buddy ext cab like 6" or so. Put 2 12s ported on 1600w and mine is atleast as loud. Its amazing how much these 8s love the lows.

18 Sierra 6.2 Z71 : 3 F8L's, DD M2a @.67, 1.95@33

05 TL build log SOLD

04 YukonXL : jvc kw-v51bt , RE 6.5c, 4 jbl gt5 12s, Memphis pr1000.1 5.5 cu.ft. sealed

Link to comment
Share on other sites

Awesome thanks! I am not sure if you saw my thread or not, but a friend of mine asked me to help him pick out subs for his 2018 2500 GMC Crew cab. he wants subs under the rear seat with a lift also. We were thinking 4 8" subs. I really like the ways yours turned out though. I am going to show it to him and see what he thinks.

Link to comment
Share on other sites

34 minutes ago, Scotnemily said:

Awesome thanks! I am not sure if you saw my thread or not, but a friend of mine asked me to help him pick out subs for his 2018 2500 GMC Crew cab. he wants subs under the rear seat with a lift also. We were thinking 4 8" subs. I really like the ways yours turned out though. I am going to show it to him and see what he thinks.

Yea I'm really not sure how people are getting 4 8s with proper air space and port area under these seats. I pretty much maxed every dimension I could and ended with 1.95 net which is slightly high for these 8s, but with the 6" port is a little low on port area for 3. Let alone 4. So I'm thinking the 4 8 boxes are really low on port area and bare minimum on airspace. 

 

I always prefer to go on the high end of recommended airspace as apposed to the minimum.

18 Sierra 6.2 Z71 : 3 F8L's, DD M2a @.67, 1.95@33

05 TL build log SOLD

04 YukonXL : jvc kw-v51bt , RE 6.5c, 4 jbl gt5 12s, Memphis pr1000.1 5.5 cu.ft. sealed

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Who's Online   0 Members, 0 Anonymous, 1180 Guests (See full list)

    • There are no registered users currently online
×
×
  • Create New...