3 subs in a box

[Alex JB 10+ year member]

As above, you need to understand how wiring a number of subs effects the load the amplifier sees.

Look at

http://www.crutchfield.com/App/Support/KnowledgeBase.aspx?ifs=subwoofer+wiring+diagrams

Plus, are the subs single or dual voice coil? (one or two sets of terminals on each one?)

 

[amp roach 10+ year member]

Heres a link to the amp.
http://www.sonicelectronix.com/item_9103_Rockford+Fosgate+Power+T500-1bd.html#

dude you can get more power for cheaper

http://ikesound.com/alpine_mrp_m1000

 

[White Rider 10+ year member]

dude you can get more power for cheaper
http://ikesound.com/alpine_mrp_m1000

Im not entirely sure if these subs really need that many watts. I think the RMS is 350 of my subs. I might eventually up the amperage, unless you know something i dont?

 

[White Rider 10+ year member]

As above, you need to understand how wiring a number of subs effects the load the amplifier sees.
Look at

http://www.crutchfield.com/App/Support/KnowledgeBase.aspx?ifs=subwoofer+wiring+diagrams

Plus, are the subs single or dual voice coil? (one or two sets of terminals on each one?)

Yea i need to do more research and just look over my amp and figure it out too. The subs are single voice coil

 

[White Rider 10+ year member]

I figured out all of my dimensions for my box size. The cubic feet I will have for each sub is .743 instead of the reccomended .8. The box is the full width of my cab and I have 2 dividers inside, to seperate the 3 subs.

So heres my question...would it be better to just run the three subs I have and them be under-boxed a bit, or just go to 2 subs and one divider in this enclosure? Also, If I ran two subs, that would get me back to 1 ohm instead of 1.33.

If I'm looking for the extra cubic feet with the three sub idea, and I move the subs closer to the back of my seat to make the box slightly bigger, will the performance of the sub go to hell being that close to the seat, or is this not a good trade off?

 

[White Rider 10+ year member]

bump

 

[Onebadsrt 10+ year member]

with that minimal of space i would prob run two subs in a ported but if you do the three i would def do sealed. As for the 2 bringing it back to 1 ohm. you need to check and see if you amp is 1ohm stable?

 

[White Rider 10+ year member]

with that minimal of space i would prob run two subs in a ported but if you do the three i would def do sealed.

This is where I was unsure as to the best route. I obviously want it as loud as I can get it, but if two subs in a ported box with slightly more amperage (because of the one ohm instead of 1.33) would outperform three subs in a slightly to small sealed box, that is what I'll do. I've got the box all cut out right now and would like to get started puting it together, if I need to port this box I'll have to rethink this a bit. Also, how close can you run a sub to the back of your seat before you lose performance? I would think that if it were a hard object, the air would bounce, but since the seat is permeable, won't it just transfer through?

As for the 2 bringing it back to 1 ohm. you need to check and see if you amp is 1ohm stable?

I'm not sure what you mean by this. The amp is advertised 500x1@1ohm, is there something else I should be looking into? Thanks

 

[Alex JB 10+ year member]

Take a look at the thread I posted about the response of my 2 sundown E8's

http://www.caraudio.com/forum/showthread.php?t=379353

take the same space and go from a tuned ported set up to a sealed enclosure and the curve is very different.

If you want loud and don't care about where in the freq range you could probably port your available space to 35-40Hz and make a lot of noise...

Bewarethough that whatever you play below the tuning frequency can damage the subs (over excursion) if you are over zealous with the volume.

I liked the loudness of my ported enclosure for about 10 mins then I missed the low frequency extension that sealed gave me (below the tune freq I had of 32-34Hz) so I've gone back to sealed for now.

If you have the right volume for 2 ported you should have more than enough for 3 sealed.

If you upped the power you could probably get as much out of the 3 sealed at the desired freq as the 2 ported... will take much more power to do it though.

 

[White Rider 10+ year member]

If you want loud and don't care about where in the freq range you could probably port your available space to 35-40Hz and make a lot of noise...

Bewarethough that whatever you play below the tuning frequency can damage the subs (over excursion) if you are over zealous with the volume.

I liked the loudness of my ported enclosure for about 10 mins then I missed the low frequency extension that sealed gave me (below the tune freq I had of 32-34Hz) so I've gone back to sealed for now.

Yes I do want loud but, not at the cost of continuously killing speakers. This is my first system so I guess I also need to say "correct" is my target. I think I will be a little over sub'd until I get more speakers in the front, I just wanted to build the box one time. The more I read, it sounds like a sealed enclosure is what I need. I'm still unsure if it is possible to get the speakers to close to the back of my seat, anybody????//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

If you have the right volume for 2 ported you should have more than enough for 3 sealed.

This is another area I'm having problems with. The spec sheet that came with the subs said they go in a .8 box. Then they tell you the specs on the port, which is pictured as internal, so wouldn't that mean less area than a sealed box? So why is this backward from everybody's opinion on here? Could it be because these are shallows? Thanks

 

[Alex JB 10+ year member]

Yes I do want loud but, not at the cost of continuously killing speakers. This is my first system so I guess I also need to say "correct" is my target. I think I will be a little over sub'd until I get more speakers in the front, I just wanted to build the box one time. The more I read, it sounds like a sealed enclosure is what I need. I'm still unsure if it is possible to get the speakers to close to the back of my seat, anybody????//content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

As long as you have an inch or two from the speaker surround to the seat you should be fine, don't want them to rub and wear out the foam.

This is another area I'm having problems with. The spec sheet that came with the subs said they go in a .8 box. Then they tell you the specs on the port, which is pictured as internal, so wouldn't that mean less area than a sealed box? So why is this backward from everybody's opinion on here? Could it be because these are shallows? Thanks

Unless the subs are only recommended for either sealed or ported use, there will be two values for the volume... 0.8 cu ft for a 12 i'd guess is the sealed volume, look for a figure of 1.5 cu ft or more in the specs for ported.

Usually the ported spec is NET volume, this is after you deduct the speaker's volume and the port itself and bracing if you plan any.