Uber

[Chevy350TPI 12]

Story:

2x 'drag event here June 4th.

Plan is to clean up, and there should be plenty of people there ... so I'll be representing TeamSSA to the max and push the site.

Uber is in 1.2 cubes sealed. Not even going to begin to guess what the hell it is running on the meter, but I'd say 135 or under. Remember, I'm in the middle of nowhere, where sealed Type R's with 500 watts and MTX 6000's rule.

I would have liked to get a 12" L7 or something to beat on, but I don't see that happening.

So, looks like I'll have to deal with what I have ... the uber, and the US Amps MD2 (~ 1500 watts). I do have a pair of older 9515's, but they're toast and there isn't enough time for re-cones.

So ... need a loud enclosure for the uber I guess. SQ ... recommended 2.5 cubes ported ultra-low.

Specs as follows:

Qms - 6.65

Qes - .41

Qts - .39

Vas - 78.2L

Sd - 0.072 sqM

BL - 31.5

Cms - 106.24 uM/N

Mms - 427.53g

Fs 23.61

Good for roughly 35mm one way linear, Xsus into the 40's.

Doesn't seem to model real well from what I have looked at so far.

Tough driver, not much real work experience.

Have 38W x 20H x 17D to work with ... I'd eventually like to just keep this as a daily box, so I might just limit it to 17W x 16H x 20D ... which is still a fair sized enclosure ... large enough to go ported ... woofer will fire up (top of the box, baffle, is therefore 20 x 17). If space needs to be added, it'll be added width wise.

I should just build something around 2.75 cubes or so, tuned ~ 32hz and call it a day. Just figured I'd throw up the specs to see if anyone has any bright ideas or insight.

[Eldorado 0]

If you are actually competing i would tune a bit higher than 32Hz.

2.75 seems a bit small for a 15 ported.

[Chevy350TPI 12]

Uber doesn't need a large enclosure to function at its best.

I'm debating building two enclosures ... one for daily, and then one for the competition - one sheet of MDF should be plenty.

[Eldorado 0]

If you wanted to be " uber" cool you would make a removable slot port

Daily and comp

Does it use a 3hp ?

[Chevy350TPI 12]

Comp box would be a lot larger than the daily box, and I'm going to be needing more trunk space shortly.

Good idea if I was just going to run the large enclosure all the time.

[Eldorado 0]

I dunno man

A 3HP ( or TC9PA) in 2.75 ft^3 still seems like you are choking it. RL-p's use a Tc9 and they are reccomended for that and larger ( 3.5)

HT drivers are made for big enclosures tuned low

[JimJ 11]

It's a relatively low Qts for a true HT driver, though...helps to explain the small enclosure size.

[Eldorado 0]

Qts of 0.4 or below indicates a transducer well suited to a vented enclosure

Doesnt really say anything about enclosures

[Chevy350TPI 12]

I'm talking in-car here ... been tried and tested that 1.2 cubes sealed and ~ 2.5 cubes ported is optimal for this driver. It's incredibly bottom heavy. HT, yeah ... you're looking at a large enclosure with two 18" PR's and 2500 watts.

I'll do a 2.5 - 2.75ish enclosure for daily, so let's just worry about the competition enclosure.

[Tirefryr 1,742]

Is this going on the Mazda?

First, I'd try and find a resonant frequency for the vehicle, and go from there. CRX style enclosures have proven to be very reliable and loud. Also might want to talk to Chad Hicks. They had some trick setup with a very small enclosure that provided a huge peak right at that frequency.

Remember though, I'm merely guessing as I know pretty much absolutely nothing about SPL.

Also, don't let Josh find out you're using his driver for SPL competition.

[Chevy350TPI 12]

I know ... I know ... I'm not proud of myself for using the uber, but I'll be careful and I won't run at full tilt, either. Hence why I would have preferred to grab an L7 or an old Tempest, or something.

I'll do my best at finding the res freq today, and yes, I'll use the hatch of the Mazda to my advantage (hopefully).

CRX style enclosure had slipped my mind - seems like it might be a good idea.

I'll have to ask around. I've never really dealt with the SPL side of things ... competition wise anyway.

[DBfan187 0]

2.77cF @ 32Hz looks good.

[Tirefryr 1,742]

I have a pair of 4" aeroports at 12" long if you need some. You're welcome to them if need be.

[CBFryman 2]

you only have 2.5cuft not including ports.

find the Fs of the vehicle with your current enclosure. Tune 5Hz less, have 2 seperate enclosures. i'd give it at least 2 4" aero ports. Round interior corners and resin all the walls. Brace with all thread to save space. Find someone with a TL SPL sensor. Do sweeps with your SPL enclsoure, shortening the port bit by bit untill you see a fall in maximum SPL. Use the same applied votlage with all the sweeps. in 30sec you can get 2-3 burps in. Start with a few Hz below your peak frequncy on the sweep, let teh coils cool, burp at your peak frequincy, let the coils cool, and if you have time try a few Hz above.

[Chevy350TPI 12]

you only have 2.5cuft not including ports.

I have much more than that available for the SPL enclosure.

[Aaron Clinton 2,372]

I am taking a guess here but for the mazda, the freq might be a little higher than I am used to, maybe tune around 48hz and burp @ 52 or so,

Chad^2 might know about a pressure box, and maybe Nick might have an idea what to do with that sub. Hehe josh is going to find out somehow. oh well.

[CBFryman 2]

Have 38W x 20H x 17D to work with ...

hell in that case, you got it made, If you can use external ports...less internal turbulance = better

[Chevy350TPI 12]

I am taking a guess here but for the mazda, the freq might be a little higher than I am used to, maybe tune around 48hz and burp @ 52 or so,

Chad^2 might know about a pressure box, and maybe Nick might have an idea what to do with that sub.  Hehe josh is going to find out somehow.  oh well.

Joshie poo ... ah well. Like I said, nothing full tilt ... because I've decided that after this, the uber comes inside, and some other little toy will replace it in the Mazda.

[jntar 15]

I am taking a guess here but for the mazda, the freq might be a little higher than I am used to, maybe tune around 48hz and burp @ 52 or so,

Chad^2 might know about a pressure box, and maybe Nick might have an idea what to do with that sub.

[Chevy350TPI 12]

Limited time, and it wouldn't be a TL.

I know ... it sucks.

[jntar 15]

My thoughts...

CRX style, use 2.5 with 3 4" aeros. Tune it at 36hz and go up from there. Your car is probly in the 50's range like most other cars I have seen. So once you get to 40+ in tuning you should be close to there. We were hitting 151 flat with a DD15 and 1 20.1 amp. In a bad car mind you.

If possible make the box as flowing as possible. Make the ports on the outside if possible. Sub on top and ports out the back or side. Keep the woofer and ports as far away from eachother as possible.

[Chevy350TPI 12]

It would have to be woofer up, ports firing out to the side.

Three ports eh ... hmmm.

I have to jump on my desktop and pull up BBP.

[jntar 15]

It would have to be woofer up, ports firing out to the side.

Three ports eh ... hmmm.

I have to jump on my desktop and pull up BBP.

<{POST_SNAPBACK}>

Atleast 15 sq.in. of port per cube so 3 should be plenty...Id rather have 4 4", but I didnt know how serious you were about winning.

[Chevy350TPI 12]

Looks like I'm going to have to pick up some ports either way then ... just flip them inside after, because this will just become my daily box after with a little port modification.

[Chevy350TPI 12]

BBP seems a little messed up ... I think it's just because the ports won't fit the enclosure - gives me 3 x 3" ports @ 16.17" long or 3 x 4" ports @ 163.9" long.