Seems like it goes crazy if we add a resonator that shares the resonace in the TL section (240/80 cm, 3:1) instead of a lower tuned resonator.
That second resonace sounds like 💩 and rings like crazy if you’re not careful
interesting. i did wonder about the drawback to this acoustic feedback strategy. i was thinking about grabbing material for the shorter one i posted; looking at those pathlengths, would you expect this to sound like ****? what exactly did the absorber stub look like? would peq help lower group delay like it shows in filter wizard?
I used a hole saw and cut into the high pressure end of the resonator so I could experiment with a variety of different length ‘pipe stubs’ stuffed with polyfil.
I still think the main issue is over exciting the second resonance in the main TL section and if you avoid that then it won’t be so ridiculous sounding (and might not be an issue?)
I wish some of the smart guys built these so we would have more/better guidance . I just hear some annoying junk that hurts my head/inner ear and then look at it in REW and realize it’s resonating pipe funk.
Look at sims with and without the big exit/mouth area and all its creating is an increasing spike around 3 x Fb.
That might be ‘punch and impact’ if it’s not instead a long decay ringing ? How do we get one without the other if using ‘excessive’ resonace?
I still think the main issue is over exciting the second resonance in the main TL section and if you avoid that then it won’t be so ridiculous sounding (and might not be an issue?)
I wish some of the smart guys built these so we would have more/better guidance . I just hear some annoying junk that hurts my head/inner ear and then look at it in REW and realize it’s resonating pipe funk.
Look at sims with and without the big exit/mouth area and all its creating is an increasing spike around 3 x Fb.
That might be ‘punch and impact’ if it’s not instead a long decay ringing ? How do we get one without the other if using ‘excessive’ resonace?
Attachments
thank you. i use onshape. if you havent used it you should try it!
If you build that one and the second resonace doesn’t suck I think I’ll join you (scaled down with a ddx12 maybe)?
Parallel or series? I wonder which one loads the lower frequencies more/less ?
Parallel or series? I wonder which one loads the lower frequencies more/less ?
Attachments
Last edited:
possibly. it has 60% sd so should be around 8.6 cube if scaling is that simple. all i know is every driver performs very differently in this enclosure and the vfx-15d4 is the only one i like. prv15sw2000 also performed remarkably well. perfect response and group delay but its max output was severely hindered by xmax limitations and unjustifiable for the size of the enclosure. if there was a sub with the same parameters and 30mm of xmax, i would declare it the winner.
You have to change your inductance as well. Inductance will also be different series vs. parallel, and that will affect the outcome. If you left the inductance for the parallel parameters but used the bl and re from series, the driver will sim like it is lower inductance which is probably why you saw it model better in series.
Im basing my expectations off of circlomanen's claims. I have seen his hornresp models for TP-BP and they all have enormous spikes around that point. Maybe the helmholtz will smooth some of the negative effects. Ill just make it removeable and find out. Also, Hornresp shows peq lowers gd, whats your experience?
nvm a quick search found the answer. https://www.diyaudio.com/community/...-series-wirings-affect-t-s-parameters.392531/
Parallel to series will be Inductance x 4.
For example if the sub is a dual 4 ohm, and each coil has a Le of say 3mH. The Re/Le in parallel will be 2ohm/1.5mH, and in series will be 8ohm/6mH.
For example if the sub is a dual 4 ohm, and each coil has a Le of say 3mH. The Re/Le in parallel will be 2ohm/1.5mH, and in series will be 8ohm/6mH.
It sounds like 💩, but is loud as heck. All of mine have been in incredibly interesting science experiments, but none of them are particularly good as an actual subwoofer.
It’s really exciting, and a great learning experience.
I stretched a couple of them way out to accommodate much lower frequencies and it was incredibly (loud), but it all starts getting weird because of what’s described as ‘group delay’ and excessive resonace funk I think.