Still ugly right now. I'm just showing the mic setup. Also, the blanket is on the headrest of my lp...So yeah. 😎
I am trying to understand your clamping techniques. I see uncured glue being imposed upon, Was this a "I can't wait project"?
If so I understand.
so this box weighs 225lbs. it also walks on its own... what to do?
before i forget i want to point out that these measurements are with a woofer that has a q of .7 which some say wouldn't work in this style of box. gd really isnt bad and listening to it is very much an sq upgrade for me.
before i forget i want to point out that these measurements are with a woofer that has a q of .7 which some say wouldn't work in this style of box. gd really isnt bad and listening to it is very much an sq upgrade for me.
Last edited:
Put some spacers in there to maintain the port (s) area on that funky warped Home Depot plywood
What are you using to get rid of the peak ? ( I’m messing with ‘equalizer apo 1.3’ on the laptop )
Attachments
have about a 5 db peaked at 77 hz. i let rew created a 24db slope at 80hz using peq which naturally brought a nice slope to to meet my speakers up front. i ended up adding a 48db butterworth at 100hz because of the of the resonance @ 151hz. i was worried that this would introduce a bunch of group delay but it measured close to the same. the IR peak moved back another 3ms in time and phase wrap at 76hz rather than 92hz. the waterfall plot and ir cleaned up significantly as a result.
No filters, PEQ only, PEQ + 48 butterworth
same order below for gd. if i had the cursor in the correct spot, you would see that the only significant difference it at 100hz on butterworth version where it added 8ms.
No filters, PEQ only, PEQ + 48 butterworth
same order below for gd. if i had the cursor in the correct spot, you would see that the only significant difference it at 100hz on butterworth version where it added 8ms.
Thanks!
I think I finally see a light in this rabbit hole. Group delay is knowhere near as ugly as commonly suggested, and removing the punch created by the second resonace might sound ‘boring’
I think I finally see a light in this rabbit hole. Group delay is knowhere near as ugly as commonly suggested, and removing the punch created by the second resonace might sound ‘boring’
Attachments
75hz is ~ the frequency of the kick drum. its not offensive as long as gd and amplitude is within reason. but this is only good for music when no other instrument is mixed into that frequency. for everything else, it needs to be flattened or it will sound like ****. in car audio applications, it can be useful because cabin gain takes effect rapidly below that point. some might mistake this for throwing away good output, but remember that headroom is a good thing, and the gain below that is a tremendous value,
Last edited:
Okay, im Venturing out into the crazier stuff (horn response is the red graph, dark green is measurement with peaking filters) in high order 1/4 wave boxes…
It seems I created a sonic sphincter, or the sarlacc pit for boba fett with the dsp at ~55hz?
It seems I created a sonic sphincter, or the sarlacc pit for boba fett with the dsp at ~55hz?
Attachments
a lot of the irregularities in the waterfall plot may be the sonic nature of plywood. now that I've made it past the proof of concept phase, i would introduce other costly methods like dampened laminations. since i cant fit the 15 in my truck without removing the entire front bench, it may be an excuse to build a dual 12 version.
GD is about 20ms worse at fundamental resonance IRL. 80hz and 105hz are about the same if not somewhat better. all resonances in useable range are at the predicted frequencies.
spl is very close as well. x3fb is less pronounced. +3db>fb IRL vs +6.5db>fb in hornresp. The first out of band resonance is higher IRL. this is also what causes the strange ripples. they clean up after dsp, but they have to be eliminated for a proper sound. this is why i think this enclosure, (and many like it) require advanced dsp.
I believe the resonance lives mostly in the helmholtz chamber. im wondering how lining the inside of the chamber would affect the response. any ideas or experiences?
spl is very close as well. x3fb is less pronounced. +3db>fb IRL vs +6.5db>fb in hornresp. The first out of band resonance is higher IRL. this is also what causes the strange ripples. they clean up after dsp, but they have to be eliminated for a proper sound. this is why i think this enclosure, (and many like it) require advanced dsp.
I believe the resonance lives mostly in the helmholtz chamber. im wondering how lining the inside of the chamber would affect the response. any ideas or experiences?
Ha, that is what i was going to add, what about adding some liner or stuff on the walls, like B&C suggests on some of their design or RICCI on some of his designs
ill have to look into it and do some testing. acoustic issues are ALWAYS better treated acoustically when possible.
I can’t get much to happen at those frequencies by ‘lining’ chambers with polyfil. It’s quit good/amazing at much higher frequencies though. (Or in a dedicated qw stub, but those are goofy to plumb into the thing)
I have to actually ‘damp’/clog up the vent with foam as @GM often suggests for it to make an appreciable change. But that’s a super thin strip of foam or it wipes out everything quickly .
Thank goodness for REW and these cheap measurement mics or I could never keep track/recall the changes in steps and compare/ contrast and figure out what’s ‘best’ .
The info youre sharing is exciting and inspirational , thank you
I have to actually ‘damp’/clog up the vent with foam as @GM often suggests for it to make an appreciable change. But that’s a super thin strip of foam or it wipes out everything quickly .
Thank goodness for REW and these cheap measurement mics or I could never keep track/recall the changes in steps and compare/ contrast and figure out what’s ‘best’ .
The info youre sharing is exciting and inspirational , thank you
Attachments
Amazing response
where is the plan and HR screen of it....
i have a hangover and cant even tell where my mouse is!!
😁