Kyle

Sorry this took so long folks. I had to upgrade mongodb driver from v2 to v6. And nodejs needed to be bumped too. I think I'll move the code to github and make it opensource so more than 1 person can make pull requests Note: There are still some broken elements but thats all on the admin side.

anyone been in contact with josh recently? I have not been able to get a hold of him.

LOL, ya, it takes work to maintain or make money. nothing is easy, but I do want to try and limp this project along if I can.

Its not (which is good news), mongodb did an upgrade from 5 to 6 and the driver I'm using in nodejs is not working with the changes. I need to make several code changes to hook that up. the second issue is a refactor I did a while back but didnt correctly update the react UI to work with the new API so we can't create or edit any systems or drivers. Its a bit more work for figure that out, but my guess is about 3-4 days tops. I might be able to do it in this quarter.

@Ricci send me a message!

eh... need to update the mongodb driver, which is a PITA bc I really need to upgrade nodejs and react too. If you dont constantly update software, eventually it deprecates. I'll get on this

nt = notext

Hey folks, I think everything runs its course and since I have not been updating db.com, I have not giving much attention to the forums either. At this point, there is a ton of great discussion here. I think invision has a self hosted option, but I don't see a price for it. It might be expensive too. In any case, these forums are $30 a month and lately I don't see the value in keeping em going because we don't have a lot of activity. I don't want all the content deleted, but I'm at a point where $30 every month is getting old for me. Any thoughts? I'm also willing to transfer ownership if anyone wants to take these over.

Probably decent, the Lab 12 has great mms and BL for its size giving it a low Q so it would work well in a horn. I don't see any reason this couldn't.

Looks like a new driver, not half bad on paper. Reasonable BL, not too too high mms. Price is solid too. https://www.parts-express.com/Dayton-Audio-MX12-22-12-Max-X-High-Excursion-DVC-Subwoofer-2-Ohms-Per-Coil-295-166

https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-parallel-and-series-resistor

The speakerpower can do 2+2 so you'll want to try and land a 2ohm load per channel. Look for a driver with a ~5 to ~6 ohm DCR and if you take 3 of them in parallel you're gonna a be right at a 2 ohm nominal load. Perfect for each side of your amp. Are you set on have 6? 4 21's is still a lot and may be easier to deal with.

The size of the driver does not make it fast or slow. In this case, you have low delay because its a sealed box. The HS-24 would perfectly fine for music, but you do need to couple it with a large box because of its higher Q of about 0.5. A big sealed box would be perfect for this driver. Also, to understand why group delay is a much more apparent with a port / horn (compared to just a driver in a sealed box) because the port, unlike the driver acts like a spring mass system. When you apply a voltage to the driver, its ridge and starts to accelerate more or less as a rigid body. But when you apply a force to a spring-mass, then it acts differently compared to the input signal. I'm honestly not sure how group delay is perceived in terms of subjective sound quality -- I hope some others chime in.

Welcome to the forum. I have not looked at these designs in detail, but my 2cents. If you're using a high sens. pro style driver, I don't really see how the system benefits from putting that kind of driver into a 6th order bandpass because the bottle neck is still the low end and its not lacking in mid-bass punch. Using the same size box, you can make the simple 4th order with a larger port with more headroom. I would be interested to see if anyone has experimented with 6th order and compared it to standard ported boxes (same size) with these type of drivers.

I will agree to pretty much everywhere here. BB is nice for things that get big, even if you don't move it much. When you do need to move it (and you will) you won't regret the BB.

no, thank god! it was just a 12" TC-1000 / Epic. Good little driver, plenty loud for my small loft.

I don't add one on my sealed HT sub, then again, I made a mistake once with the amp maxed out and now I have a voice coil ring dent on my metal dish cone Still works fine tho!

Looks nice! I bet they sound fantastic!

I tend to think its a glue problem, or primer problem.

Hard to tell what that might be, best to return it if you can? The noise may be coming from the motor or voice coil. The phase plug won't likely be making any actual noise itself, but any number of things could be wrong with that driver, its very hard to tell sometimes what exactly it is.

Any small issue with glue or primor can lead to failure. Its a bit tricky and takes precision. Hopefully Eminence can get those fixed for you

Welcome! Are these new drivers or did they fail after some time?

Could be room issues. Its pretty easy to stuff your ports and get a sense of what a sealed box sounds like. The larger box volume won't negatively affect the midbass at all. Only really increases efficiency down low. Just make sure to turn off your high pass filter once you seal it... and go easy at first! But what you really might just need it to figure out if you have some standing waves in that room that negatively affect the bass. Just move the subs and see what happens. I would also consider getting a higher efficiency 18" driver and just switching that. But before doing anything costly, what sort of power are you running to your subwoofers?

Gotcha Charles. Glad you like em! lets see some pictures

Old thread! Yes @Charles the dual 4" ports will have a measurable advantage over the single, even with flaring. PSA subwoofers are interesting to me, it feels like they lean heavy on the driver and its motor and squeeze it in a smallish box (not every sub they sell is small) but many of the B&C drivers they use could gain more from a larger, box, however there is something to be said about how capable they can still be in a reasonably size boxed for home applications. Its kinda cool actually. What is the TV1812? I see V1812 with a slot port? that is ~6.1 cubic feet or so while the Rhythmik is closer to 8.8. If that's is accurate, then there is doubt the larger box and port will have a big advantage down low. But I could be wrong about my numbers ... someone should double check.