The cute 'lil guy project - Being different is good... or is it

[s_ribs]

Threats of coming off sale pushed my impulse buy and created this project. After finding my Exile 12" sub and 1000 watts of power a bit too much, I began looking for a new stereo set up.

Initially I thought going subless would be the answer, but we all know it's a spendy battle to create enough bass fill in E30's without them.

Solution: Elemental Design e3.6 6.5" sub and my first audio forum build thread.

3 reasons I decided to try this route:
1) What I really wanted was bass fill, not pounding. After spending a weekend in my dad's '04 S4 I realized how much I like a very full and surrounding sound to a stereo, so I had to figure out how to get that. Add to that how little I listen to rap these days.
2) At $39.99/per they are cheap! Even more, going back to full retail of $84.99/per soon I had to do it.
3) Most importantly though, found a few recent builds with them for SPL and found that they can put out some serious dB's with the right set up. My biggest concern was that positive reviews were fanboy hype and presence would be lacking. http://forum.edesignaudio.com/showth...3-3-73024.html Not concerned about that anymore.

Well, 4 reasons - it's different.


Pics-







Size comparison pics-
Keys:


Exile 12" sub, kicker zx750.1, 1.25cF box:

[george graves]

Small woofer is small! Subscribed!

[s_ribs]

With the intro out of the way...

These are the dual voice coil 2-ohm units.


Specs:

Qts: .29
Qes: .30
Qms: 10.5
Fs: 28.00Hz
Re: 3.2
Vas: 22L
Mms: 50.0g
Bl: 13.30T*m
SPL: 85dB
Sd: 114cm²
Xmax: 13.0mm
Voice Coil: 38.0mm

Magnet Width: 5.000"
Cutout Diameter: 5.700"
Mounting Depth: 3.518"
Weight: 7lb
Total Height: 4.000"
Displacement: .04 ft³
Outside Diameter: 6.75"

Plans:
Will need power:
-Thinking Phoenix Gold RSD300.1 Why? It's inexpensive ($130) and allows better sub tuning than a 2/4-channel. If there's a better option (similar price range) I'm open to something else.
-They like power, this will be in the moderate to upper range. Should move them quite nicely.

Box:
-Thinking I'll have to do ported. Never built one so I'm a bit cautious on designing and executing the build.
-Per eD specs, intend to have 1cF volume and tune to 30Hz.
-Will be sealed to and fired through the skipass.

Couple of things to consider:
-What diameter port tube? From reading, too small can create air noise. But bigger means longer length - and it needs to be one tube, not two, or calculations get screwy. It doesn't need to be straight from what I understand though.
-Are those eD specs best or not. Going for SQ not SPL. Looking for bass presence and fill, not boom (woulda kept the exile in if I wanted to rattle everything loose and wake neighbors).


Hoping to get started in the next week or two as school/other projects allow. Will keep this thread updated as I go along!

[s_ribs]

Small woofer is small!

[bmwman91]

The boominess might have been due to a setting on the amp, or just the cabin gain of the vehicle. It depends on a lot of factors.

The enclosure should be made from 3/4" MDF, minimum. Bracing is not really optional. If you plan to run 100W peak to it, you shouldn't use less than a 2.5" ID pipe, and it will need to be ~13" long at that diameter. Flared/flanged ends help with the extra noises. Even with that, you will get a lot of extra noise below 40Hz, but usually music has very little content down there.

Vented boxes reduce the damping on the driver cone, so over-excursion is also a concern. You should really have a low-pass filter on there set at ~50Hz too. The group delay on ported boxes is terrible around the port frequency anyway, so you want to start cutting it off around there.

Download WinISD Pro. It is free and very useful. You will want to pay attention mainly to the transfer function plot, the rear port air velocity plot (keep it below ~15m/s in the range of frequencies you plan to play) and cone excursion. You can adjust the rear port velocity by changing the port dimensions & tuning frequency. The other stuff is affected by box/port design parameters.

Good luck, speaker building is fun!

Oh, and one last thing...avoid installing amplifiers on the enclosure. Electronic devices and vibration are not the best mix, usually.

[s_ribs]

The boominess might have been due to a setting on the amp, or just the cabin gain of the vehicle. It depends on a lot of factors.

That came off wrong: Exile wasn't boomy. In fact, it's one of the best 12" subs I've heard. It was just a lot, and more than I want in this car. While it can be turned down... why run a engine built for 1000 hp at only 500 hp? Over building can be good for durability, but only to an extent is it worth it. I'd rather sell that set up or save it for later use. My point was I a) boomy set-up's suck; b) am not looking for a SPL drag racing set-up.

Download WinISD Pro. It is free and very useful. You will want to pay attention mainly to the transfer function plot, the rear port air velocity plot (keep it below ~15m/s in the range of frequencies you plan to play) and cone excursion. You can adjust the rear port velocity by changing the port dimensions & tuning frequency. The other stuff is affected by box/port design parameters.

Already did a few weeks ago. Not a clue how to use it properly though. Will likely spend more time figuring it out before I start cutting.

Oh, and one last thing...avoid installing amplifiers on the enclosure. Electronic devices and vibration are not the best mix, usually.

I'm new to a lot... but I'm not that much of a newbie. I plan on letting them slide around the trunk floor, of course. ;)

No commentary on the tuning specs you mentioned at the moment. My brain is a bit distracted with fun statistics formulas and time to study!

Appreciate the input.

[bmwman91]

That came off wrong: Exile wasn't boomy. In fact, it's one of the best 12" subs I've heard. It was just a lot, and more than I want in this car. While it can be turned down... why run a engine built for 1000 hp at only 500 hp? Over building can be good for durability, but only to an extent is it worth it. I'd rather sell that set up or save it for later use. My point was I a) boomy set-up's suck; b) am not looking for a SPL drag racing set-up.



Already did a few weeks ago. Not a clue how to use it properly though. Will likely spend more time figuring it out before I start cutting.



I'm new to a lot... but I'm not that much of a newbie. I plan on letting them slide around the trunk floor, of course. ;)

No commentary on the tuning specs you mentioned at the moment. My brain is a bit distracted with fun statistics formulas and time to study!

Appreciate the input.

Good times. Get to know WinISD. It will be your best friend.

[s_ribs]

Did some cardboard mockups of the box yesterday. Took a while to find dimensions and shape that allow everything I want to fit with the smallest depth possible. Quick paint drawing of what I'm thinking of-




At this point I'm rethinking things and planning on trying them in a sealed box. Can't screw it up and not sure I feel like the risk of screwing up the port details. Plus, sealed will bring out more really low end than ported. Winisd shows ported being much flatter but dropping off drastically on the low end.

Curious if that power will be far too much... we'll see! Power specs on eD's website are pretty vague so I'll have to call them.

[rhett325i]

Cool project, but you could get the sound you are looking for with a 10" Luke box and any 10" sub.

[Van Westervelt]

The whole concept here is less space and less weight. I am excited to see how this project comes out. I might need to copyright that "T-box" concept, lol. And you better not get any sawdust in my paint!

[bmwman91]

That T-box is not going to sound good. Internal reflections will be trememdous, and it will sound bad.

[s_ribs]

Cool project, but you could get the sound you are looking for with a 10" Luke box and any 10" sub.

So... lowered, BBS's, S50 swap. What else does everyone do? :p

Fun project and trying something different! If I'm going the boring been done already route I'll stick with the Exile 12 and not waste my time with a little 'ole 10.

That T-box is not going to sound good. Internal reflections will be trememdous, and it will sound bad.

I'm completely fine being wrong here, but... any real data to add?

If this were a ported box I might agree with you. Every bit of research I've done says volume is volume - shape is irrelevant. In theory waves will cancel themselves out in anything but the perfect box design. But even if that theory is true, it will never be realized within the dimensions of a cars interior (wavelengths at these frequencies are loooooong). The box for my Exile was 'L' shaped and worked just fine. Only complaint I had with it was not being sealed to the cabin.

I have wondered how more volume by one and not the other could be an influence though (variances with running 2 subs in one box, vs. 1 sub). If I find a reason that it could be then I will move one section of the upper 'T' down to the bottom.

[s_ribs]

The whole concept here is less space and less weight. I am excited to see how this project comes out. I might need to copyright that "T-box" concept, lol. And you better not get any sawdust in my paint!

That assumes you will be painting sometime in the near future........ :yawn:


















;)

[bmwman91]

I'm completely fine being wrong here, but... any real data to add?

If this were a ported box I might agree with you. Every bit of research I've done says volume is volume - shape is irrelevant. In theory waves will cancel themselves out in anything but the perfect box design. But even if that theory is true, it will never be realized within the dimensions of a cars interior (wavelengths at these frequencies are loooooong). The box for my Exile was 'L' shaped and worked just fine. Only complaint I had with it was not being sealed to the cabin.

I have wondered how more volume by one and not the other could be an influence though (variances with running 2 subs in one box, vs. 1 sub). If I find a reason that it could be then I will move one section of the upper 'T' down to the bottom.

With low frequencies, shape is less of an issue. However, even with subs designers typically tend to avoid using extreme aspect ratios even in rectangular boxes since it can lead to issues with reflections interfering with performance. The T box will probably perform similarly to those bass-tube subs, which are a little boomy IMO.

Realistically, the T will probably be OK in a car since there is a ton of other road & engine noise anyway. If it is all that fits then go with it. As you said, ideal enclosures are generally impractical in cars. There are a variety of "non-car" brand drivers out there that will give super deep bass in small enclosures, but people are hesitant to put them in their car for some reason.

[s_ribs]

Appreciate the expansion of thought on it. I'll do a little more looking around regarding extreme shapes - decent chance that most "shape" discussions still orient around a basic cube rather than odd extensions.

Completely agree on the "non-car" brands! I'm planning on picking up some Dayton Audio speakers for the rear fill. As long as you can find 4-ohm, it's funny how much cheaper they are.