Samps

Is the Pi cooling plug effective? Haven’t seen it used anywhere else which leads me to believe it’s not very effective.

Here’s the rest of that system. The sub is behind the tv. I built everything here that’s made of wood.

Size next to a sofa chair.

This box used two 4x8 sheets of 3/4” arruco ply from Home Depot. About $100. Cut one sheet into the four sides then the other sheet for the top, bottom, port, and bracing. I’m still using this sub, which is saying something considering how many I’ve tried. Crazy thing is, I have not seen the red light on the inuke yet. Even when I think i’m really pushing it, I’m still only seeing the third light flicker. But I don’t watch many movies in this room so it rarely gets the 20hz content. For music it’s silly inside a normal sized house.

I should probably know this but is the name: La-vo-chay La-vo-say La-vo-see

Can the impedance sweep be done at low level, or does it need to be done with an amp?

Looking forward to the single driver cab. I bet it's a popular design if it's easier to build than the othorn.

Thanks. I haven't decided on whether to build the half skhorn or try to modify my existing ported cab. My theory is that I already have the ported section and it performs exactly how I want it to. Seems simple enough to just add the horn section onto it. Biggest difference would be that the mouth would not be adjacent to the port. I could actually build the mouth as big as I want if it would help any.

How does the time alignment work on a design like this? Wouldn't the horn path delay the HF output longer than the LF output from the port? Or is it close enough to not matter much? Or is that part of the design that needs to be factored in somehow during the design process? I was considering an attempt to add a horn section onto an existing BR cab, but wasn't sure what all needed to be accounted for.

Forgot to update this thread. Sub has been up and running for a while. Turned out exactly how I wanted it to. Subjectively I'd say it sounds better than my previous diy subs at the same spl. It can dig low enough but still has that impact that seems to be missing with some of the high excursion drivers. Good all around performer. Currently it is firing directly into a corner. I spun it around to get a pic. Sweep is at mlp with no eq other than the hpf bw12 @20hz. 6th smoothing. Pretty good response to start with before any eq. Thanks for all the help guys! Learning to take impedance tests has and will change all of my current and future builds.

Minor update: It's black now. Hopefully making noise soon.

Lol, that desk is not stable at all. Cheap IKEA type construction. I added some braces to it just so I could make it useful, but I wouldn't call it stable in any way. Maybe I'll try sitting it on the floor. I'm also planning on making my own grill for this, since nobody makes a damn 21" speaker grill. I guess all the pro audio guys using these either have them in horns or make their own grills. So, question is, how much clearance should I leave above the surround?

I ran the slowest sweep REW allows and the result was exactly the same. Not sure where that waviness comes from. It didn't show up in any of my tests of other speakers around my house. Possibly still some air leaking out, I didn't use any gasket material under the driver since this is still under construction. I'm pretty confident this is working out as planned, so I'm going to move forward with sanding and paint. It won't be a show piece, but decent anyways. Thanks for all the help!

Looks better screwed in and standing up. The trace has more wobble in it, but the impedance minimum came down to 21.27hz. And the lower peak is a bit higher and sharper. Also added a comparison between unscrewed laying down and the screwed standing up.

I thought the peaks would only be the same height if the tune was at the drivers FS? Winisd predicts similar lopsided peaks as I'm getting, but the lower peak is not quite as bad. Hopefully it all works out once I add screws and stand it up.

Thanks, I'm going to put in a few screws tonight, and test it upright to see if that changes things.

Took a impedance sweep. Looks like it's currently around 23hz. Not sure if that might change once the driver gets broken in? It may shift a little lower when the cab is standing upright. It's currently laying on its back because I didn't want to screw in the driver. Once it's standing up, the port may act a little longer since it's on the very bottom. I was hoping for a little lower but not sure if I want to mess with it. 22hz in the model works out pretty well with the inukes 20hz HPF. Adding length to the port isn't a problem, I left myself plenty of room to extend it. I did add the corner deflector in the back corner, but didn't get the impedance test of the before and after.

Yeah, that's what I was thinking. Now that I can do the impedance test ( thanks Mike ) I feel like I can test things and make useful decisions. I doubt it will make a big difference unless I'm pushing things pretty hard. But it's simple enough to try.

Test from a random htib speaker.

Would there be any benefit to adding a deflector to the back corner of my port? Currently there is a pretty big difference in volume of that corner vs the rest of the port.

I built and sold two THTs that were never finished. I figure you have to test it before you spend all that time finishing, but then it never gets done. My impedance jig isn't working correctly. It will make a sweep but the level is super low and the graph doesn't look anything like what I've seen before. Pretty sure I built the jig correctly, but not sure I'm using the correct settings in REW and or computer. Been testing a little bookshelf for practice.

About half way done with my ported DS21. Thought I'd share some pics. 23.5 x 23.5 x 49.5. = good use of ply. 13.4 internal -1.0 for port -.5 for driver -.15 for bracing = about 11.75 net cubic feet port is 8 x 8. Length is a guess at this point. It's 22.75 in actual length, but the effective length I'm sure is going to be longer. Hoping for 20-22 hz. I built a jig to measure, but can't get a good reading yet. Going to be painted. Bridged on a 3000dsp.

Awesome! 12 is perfect for the space I have. Even if I have to cut a bit down low, that should only help the amp.

Thanks. I'm pretty sure 20 is way more than needed. 12 makes a nice model without a HPF. 14 looks great after the HPF is added. But once it's in a room, in a corner, that 12 cube model might be perfect.

I got a DS21-4. Going to build a ported cab tuned to 20hz. Models suggest roughly 12ft3. Going bigger just seems to create a larger hump at tune. Any advice on the best size for 20hz? I could go up to 20ft3. The WW cab is around 11ft3, but I can't tell if that was for best performance or to keep size reasonable.