Jeff_Hunt

Going to build my first DIY sub

Long post, sorry.

After lurking here in DIY for awhile I think I'm finally going to go for the gusto and build a sub. But first, a few questions.

I'm basically looking at building a sealed sub with a mid-Q (.707) using plans from www.adireaudio.com. Though I haven't done any in 2-3 years I have a pretty good background in wood working and MDF fabrication so I'm not really concerned about that part of the process, unless anyone has tips that are speaker-building specific that is.

My question is this, which to buy? Initially I was looking at getting the PartsExpress 120 W plate amp and a Shiva Mk IV. As I look around I see that PartsExpress sells a 250 W amp for only $130 and that seems like it wouldn't be a bad idea to go ahead and get it, I'm trying to keep this cheap, but $30 isn't too much more.

Next I notice that the Shiva is $125 from Adire and that the behemoth Tempest is only $150. Once again, maybe that's a good upgrade?

Do you guys have any opinions on Shiva vs. Tempest? Do they basically sound the same?

I'm building this mostly for home theater use, but I do enjoy listening to music from time to time. I'd say 80% HT and 20% music. I listen to alot of rock, but also a good bit of classical. Initially I wanted to build one of the lower Q enclosures, around .6 because I like the idea of accurate bass but I've recently decided on the mid-Q because it should have better crowd appeal (lots of friends come to watch stuff on my system) and better SAF ("why does it have to be so big?"). High-Q is right out for me because I'm not really into the overly "punchy" bass thing.

So now falling down my slippery upgrade slope I've gone from $225 in parts to $280. Is that $55 well spent? That's before my building and finishing materials and tools. Although I think the only tools I'll need are my own circle jig and a new router bit. I'm trying to keep costs down as much as I can, but it seems like it might be worthwhile to go a little bigger.

Any advice, comments, thoughts?

Stephen Hopkins

The shiva and tempest are both great drivers. Just remember that for the tempests you're going to need a noticably bigger box. Since you listen to about four times as much HT as music I think a ported sub would be a better choice since there's alot of LF and subsonic in movies that goes well below the FR of a sealed Shiva or Tempest.

I think a better use of your $$ would be a Stryke Audio SAE 1201. It was designed to be a Shiva clone and does it nearly exactly... and for only $99. That paired w/ a 380W plate amp from Rythmik Audio for $155 in any of the Adire reccomended ported alignments would make you very very happy for movies and music for around $255 + SH. If you think you want to go bigger, the Tempest for $150 is still a great driver and a great price. I would still go with they Rythmik amp, but if $305 + SH is too much, you'll still be extremely happy with the SAE1201/Rythmik combo.

Either way, a larger ported box will serve you much better for your heavy percentage of music listening (you can fairly easily reach 20hz w/ either driver in the right enclosure, especially in a smaller room). The ported Adire alignment is still only about an 18" cube so don't think all ported DIY subs have to be huge. The Adire alignment also has a very low group delay so you won't be sacraficing much accuracy from the sealed enclosures and you'll be picking up quite a bit of extension and probably some output as well.

Patrick Sun

Go with the Tempest, it's more forgiving on low end bass than the Shiva. Stick the Tempest in a 5 ft^3 sealed enclosure, or a 8 to 9 ft^3 ported enclosure, tuned to 18Hz.

"I am a leaf on the wind, watch how I soar!"
Patcave | 2006 Films | 2007 Films | Dragon Con 2008

Adam Demuth

Check out apexjr (.com sorry, new member), he's super nice to deal with. He has overstock amps from the Cerwin Vega CVT-300S sub for $125. I can't comment on this amp as I haven't heard it yet, but i've herd decent reviews on the sub that they were originally in.

Andrew S-

Welcome yo DIY. DIY subs are very simple and a great way to start out.


How large of a room is this going in? A shiva off the Rhythmik amp should be more than enough for most rooms for movies. Should also be a nice accessory for music.

Definately go ported. If you do not port you will not get the subsonic bass extension that gives the impact on a lot of movies. Get a program such as WinISD and model up the drivers you plan on using in different boxes. Try and get your F3(-3db point) down as close to 20hz as possible while maintaining a smooth frequency response.

Good luck and have fun.

GrahamT

Download Lspcad from Adire. It already has the drivers loaded in. Also going with the plans from Adire will ensure good performance.

Bob K

As the owner of a sealed, downfiring "mid-Q" Tempest (design right off of the Adire website) with a 250W plate amp, I can attest that that design is bone-jarring for home theater and subtly fills in the bottom octave on classical music (e.g., Mahler's Sixth). A satisfying combination.

Adire Tempest Construction Pix: http://www.audiocircle.com/circles/m...view_album.php

Jeff_Hunt

Bob, that's a nice looking sub!

I think ultimately what I build is going to depend completely on how much money I can scrape together, but I'm going to shoot for the Tempest and see what amp I can afford. Coincidentally, I may have a thread with LaserDiscs for sale soon over in Software for Sale...

I definitely hear what you guys are saying about ported subs, but I really want to hear what a sealed box sounds like, and this being my first foray into DIY speakers I'd like to keep it as simple as possible.

Wayne Ernst

Jeff, If you are following one of the "tried and true" plans for a ported box, you should be fine. A 5 foot section of 4" PVC pipe only runs about $5.00 at Lowes. Plus, there is just one more hole to cut - for the port.

I can understand how you would like to keep it simple. However, also bear in mind that 3 months from now, you don't want to *wish* you had done it a little differently. Then again, I guess all of us get that feeling - which is why we keep coming back for advice on our next upgrade.

\"My reality check ... just bounced\"

Geoff L

Building a many number of both, unless music is your main listening preference (99%) and your willing to go with a bigger box, (Q-.600) and the Tempest, I really belive when all is said and done, you may very well wish you'ed gone ported-12 regardless of the drivers mentioned for use.

I do prefer sealed for most music, but even with 2 sealed 12's that are flat in room to 21-22Hz, nothing replace the EBS or even a slightly smaller 4th order ported, for bass duty "in movies". The impact seems just better and the ported just crusies along untill really pushed..
The ported 12 uses the PE-250, plenty of power, and the sealed subs use Rythmiks-380's with their toggel goodies. All are room fixxed/flattened with a pari-EQ.

If only you had both alingments "using the same driver you might choose" (sealed & ported) in your room to compare, the choice might be much easier to make.

I thought my sealed 12's did an excellent job for movies! Untill I built a 12" EBS (same driver) tuned to 19~20-Hz and then heard that doing LF duty for movies!
The EBS is definitely no slouch with music either, but man, movies are some'n else....

Bottom line:
If I had to make a choice and only keep the two sealed 12's, or the one EBS ported 12 sub, ~{take my sealed subs please}~....

Theres advantages to both type subs sealed and ported, and I certainly understand trying to keep the budget in check. You can always build a ported sub later if you did choose a sealed design to start.

Got to go with the majorty here, even tho you like your music and think the lower Q might be best, I belive a ported lower tuned 12", would make you happiest over all...

Could be wrong tho...

Good luck choosing
Geoff

Jeff_Hunt

Geoff (and others),

I understand what you're saying, and there's a good chance that you're right. The catch is, I know myself. Actually building a ported sub isn't really the problem, deciding what to build, how to build it, how to tune it, etc. is. I'm the kind of person who will get so caught up in the details that I'll get mired down and never get it done. It's more parameters for me to obsess over. That's the main reason I wanted to stay sealed, to keep it simple.

More than anything I really just want to build a sub for the experience of doing it and to improve the bass in my system over the Energy e:XL S8 that I'm using right now.

More details that might help: a good bit of my listening happens at low volume levels because I have two very young children and my main time to watch something is when they're both asleep. That's not to say I don't crank it up and play, I do and I really savor those times, but the majority of the time I don't. I didn't really think to include that tidbit in my original post, but I think it's important. I don't actually know what design is best for that, but, like I said, I'm looking at this as more of a learning process. I'm pretty sure anything I build will be leaps and bounds better than what I'm currently using.

Oh, and the room is pretty big. I don't remember the exact measurement, but it's something like 12' x 22'

Again, thanks for all the responses, advice, and info. I'm going to have a tough time actually making the decision. If there's anything else to add, keep it coming!