08 Dodge ram single cab

[JoshC 10+ year member]

Almost done with my build, heres what ened up in the truck.

The Truck

View attachment 26530214

Set up

HU is a Alpine CDA-105

Front stage is Hertz 165 midwoofers w/ DD T2 tweeters

Rears is a pair of Fosgate 3-ways (40wrms)

powered by a db drive Okur A5 90.5

As for the sub ive went with a JBL originally, wasnt laoud enough/never got box right. Ened up changing to a Obsidian 12 D2, box is under way(had to remove rear tray, cut wood to shape vs just dropping a box into the tray like the JBL)

Will be powered by a Memphis PRD1000.1

Have kicker 4gauge runs, stock 136amp alt, and original batt. Also used 25ft of Audio Technix 60mil for front doors, this is my first real build.

Few pics of what we got done today with the box, will get pics of rest of equipment final install day.

Box is going to be around 2cu ft @ 33Hz using 2 3' precision ports, using 3/4mdf and 2 gallons of fiberglass resin to make inside smooth and rounded

View attachment 26530204View attachment 26530205View attachment 26530206View attachment 26530207

Click to read more...

 

[THATpurpleKUSH 5,000+ posts]

Those ports should be around 16 1/4 long including the flare for a 33hz tune. You posted something a while back that made it seem like your box builder wasn't tuning things correctly so just be aware.

 

[JoshC 10+ year member]

Those ports should be around 16 1/4 long including the flare for a 33hz tune. You posted something a while back that made it seem like your box builder wasn't tuning things correctly so just be aware.

Really? He said they need to be 12in long each for 32-34Hz, 2 3in ports in 2cuft

 

[THATpurpleKUSH 5,000+ posts]

Put the numbers in yourself to verify it: Products Menu

 

[JoshC 10+ year member]

Put the numbers in yourself to verify it: Products Menu

You are correct sir, thanks alot. Ill make sure hes not making them too short

 

[THATpurpleKUSH 5,000+ posts]

If he designed the box with the shorter ports, the volume will be incorrect if you lengthen the ports. The volume of the box will need to be increased to compensate for the added displacement of the longer port. I wouldn't go to that box builder any more. He may be able to build, but if he can't calculate things correctly, then theres no point.

 

[JoshC 10+ year member]

If he designed the box with the shorter ports, the volume will be incorrect if you lengthen the ports. The volume of the box will need to be increased to compensate for the added displacement of the longer port. I wouldn't go to that box builder any more. He may be able to build, but if he can't calculate things correctly, then theres no point.

Yea i just asked him but he said we changed the volume from his original design so he needs to recalculate. But he said he will make sure its correct, ill be sure to post the final specs he uses and going to get some more progress pics up tomorrow when he lays some fiberglass. I told him before he started that on this box he needed to step his game up, so well see what he ends up doing. Im planning on making a few vids of the Obsidian in action once its done too, so ill see what you guys think as well.

 

[pro-rabbit 5,000+ posts]

What all is he glassing? If he has incorrect measurements with basic math I'm not sure how he will do with trying to figure a more complicated situation.

Anyway, hope all goes well. I'm sure at the very least he can make the ports a mile long and cut em down to give the sound you want.

 

[JoshC 10+ year member]

Just got this pic from him, this is how he got the total volume down. Ports are 12in each and im not positive about total volume but according to his program its at 33Hz

He used Winisd to get these numbers

View attachment 26530375

Back plate will be mdf except fiberglass around the pillar. Also glassing all the edges to smooth roundness. Should finish up tomorrow or friday so ill get more pics up tomorrow

More equipment pics

View attachment 26530378View attachment 26530379

 

[THATpurpleKUSH 5,000+ posts]

If the ports are 12in long and tuned to 33hz, then volume should be around 2.2cu/ft

 

[JoshC 10+ year member]

If the ports are 12in long and tuned to 33hz, then volume should be around 2.2cu/ft

Yes and with port displacement and sub displacement it should be right at recommended volume. (1.75-2cu^ft)

 

[THATpurpleKUSH 5,000+ posts]

Yes and with port displacement and sub displacement it should be right at recommended volume. (1.75-2cu^ft)

If its any less than 2.2 after displacement, then I guarantee your tune will be higher than 33 with 12inch long ports.

The box I just built for my winter beater is 1.85cu/ft with 2 3in pvc ports 17inches long and that gives me a tune right around 32. Your box will have about the same volume and port area but around 5in less of port length. Everything is pointing to a high likelihood that your box will not be tuned to what you want it to be and instead its pointing to something between 35 and 38.

This just keeps going in a circle. I give up. I will wait to see the finished product and the sound it produces.

edited as my thoughts came together more.

 

[JoshC 10+ year member]

If its any less than 2.2 after displacement, then I guarantee your tune will be higher than 33 with 12inch long ports. This just keeps going in a circle. I give up.

Like i said idk he put the numbers into winisd. idk what the volume is, and neither you nor that web site stated if you were to use gross or net volume. just sayin lol i never said i ran any numbers

 

[THATpurpleKUSH 5,000+ posts]

Well maybe you should learn to run the numbers to verify that other people are or aren't doing the job correctly. I just have a bad feeling about it, from what you have said so far and your posts in the past about subs in boxes this guy built as well.

 

[JoshC 10+ year member]

Well maybe you should learn to run the numbers to verify that other people are or aren't doing the job correctly. I just have a bad feeling about it, from what you have said so far and your posts in the past about subs in boxes this guy built as well.

Yea i know what you mean. There just wasnt really any options in this town and he did it for an amp. But i did find another builder here very recently that looked to do good work, but he had some odd things to say too lol told my 90rms isnt enough for comps i needed to go coaxial if i wanted them to sound good.

EDIT: I just talked to him, the box has a volume of 2.4-2.45cu^ft so its going to be right about 2.2cu^ft after all displacement.