This Has ‘Potential’ noisy Bass reflex port size issues @ 200cm2? 30m/sec @/below tuning(maybe?)
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The port was 33cm but I was changing the value around just before posting so that may have something to do with it, I am not in front of a computer right now but I do think some filters could fix the air velocity.
Lowering the voltage to around 28.3v might also help reduce the turbulence slightly, I changed it to 30v to push it just a little bit before posting.
Nevertheless, I did state that this is a work in progress and I am still contemplating some design choices.
At any rate I am not overly concerned about a potential turbulence at these sound levels in the rare occurrence of a full signal swing pure sine at 25Hz or so.
The point was that I am planning a design for cheap drivers with less xmax and plan on having several slightly smaller boxes than going huge because it is a pain to move those around, and I like bang per buck coupled with decent efficiency. Absolute SPL is not my primary focus.
Lowering the voltage to around 28.3v might also help reduce the turbulence slightly, I changed it to 30v to push it just a little bit before posting.
Nevertheless, I did state that this is a work in progress and I am still contemplating some design choices.
At any rate I am not overly concerned about a potential turbulence at these sound levels in the rare occurrence of a full signal swing pure sine at 25Hz or so.
The point was that I am planning a design for cheap drivers with less xmax and plan on having several slightly smaller boxes than going huge because it is a pain to move those around, and I like bang per buck coupled with decent efficiency. Absolute SPL is not my primary focus.
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So why are you are posting a 280 pound 40.75" x 30.5"x 30.5" cabinet?
https://www.diyaudio.com/community/threads/peavey-udh-subwoofer-plans.265322/
Lol Art, i forgot to add that it was just for giggles.
just wondering what 4 15SW2000's do on that box 2kW each so to feed 8kw to each cab
the guy who shared the plans says he have 8 of them !!.
135dB SPL max continuous, 140dB SPL max peak ( with the low spec 15" BW from Peavey )
just wondering what 4 15SW2000's do on that box 2kW each so to feed 8kw to each cab
the guy who shared the plans says he have 8 of them !!.
135dB SPL max continuous, 140dB SPL max peak ( with the low spec 15" BW from Peavey )
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Now I know why audiophiles are always claiming BP's are nothing but "one note" wonders. The UDH has a TERRIBLE response with a 150hz low pass filter. I would NEVER design a BP with a hump in the curve like that. The 45-70hz range NEEDS to be under 106dB's.
ic, looks like it need to be tammed with -6db Bell EQ , maybe a Q of 1.0 or .7
but it was just for giggles
just wondering what 4 15SW2000's do on that box 2kW each so to feed 8kw to each cab
the guy who shared the plans says he have 8 of them !!.
btw, the spec sheet says 1991 !!!
32Years old!
but it was just for giggles
just wondering what 4 15SW2000's do on that box 2kW each so to feed 8kw to each cab
the guy who shared the plans says he have 8 of them !!.
btw, the spec sheet says 1991 !!!
32Years old!
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Quite a show!!
Those hit low!! You bass NUT!
138dB @27Hz
189 times 4 is like 760 for 4 PRV's
One b&c 18sw115 around the same but
Don't have the cone area of 4 15's
Only thing is that is neodymium
So less weight
30lbs vs 115lbs for 4 PRV's
1700rms vs 4000rms 4PRV's
1,210 cm2 sd Vs 3,632 cm2 sd 4PRV's
Those hit low!! You bass NUT!
138dB @27Hz
189 times 4 is like 760 for 4 PRV's
One b&c 18sw115 around the same but
Don't have the cone area of 4 15's
Only thing is that is neodymium
So less weight
30lbs vs 115lbs for 4 PRV's
1700rms vs 4000rms 4PRV's
1,210 cm2 sd Vs 3,632 cm2 sd 4PRV's
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Does that steep crossover slope really get rid of all that nastiness up top or is it still there to mess with the next set of speakers and what we hear? This is why driver position is so critical at an odd harmonic (or additionally the lii location of exit to a parallel-series qw pipe in the same way) ?
GM is right! We gotta address this .. Nobody seems to wanna experiment to see this dramatic change or results of using these locations in ‘qw pipes’ 🥲 You can’t just drop a driver into a pipe and then call it good. There’s more to it and some of the most important parts are otherwise missing, or simply not understood And then left to dsp/crossover to fix/bandaid electrically instead of ‘acoustically’ ? I don’t think it ends up sounding nearly as good or worse (??)
In reality that pipe junk is a bigger issue then depicted @ crossover slope/eq/dsp so easily it seems If you don’t address it it’s still a curse it seems. 🥲🥲 built so many to compare and contrast to snuff this issue out I’m forever to only ODTL or parallel/series higher order version (damped and sized precisely in horn resp so it all converges /exits at the odd harmonic)
this plagued paraflex in many ways (lengths and ‘Q’ of the multiple weird resonators were quite a ways off in the past) and it really helow once you polish it up in reality and it all works MUCH ‘better‘ and is audibly obvious and lovely sounding .
I’m guessing(like all of us it seems) it matters increasingly less as a PA speaker outdoors with no boundary, but boy is it obvious the more you bring it inside or the real pronounced disaster in the car audio😝😝👍🏼👍🏼💚💚
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I'm quite sure lining will work. 2 pillows worked for the 4 $29 JBL 12 Devastator on avsforum.com. The thread has measured results. I know the Devastator is a BP6P and my model is a BP6S, but the same principles should apply.
I'm a basshead, i just play around with the speaker distant settings in the AVR until I get the bass hitting RIGHT, at the middle listening position.
I'm a basshead, i just play around with the speaker distant settings in the AVR until I get the bass hitting RIGHT, at the middle listening position.
Experiment with ‘PH1’ mode and a 3:1 length ratio off the front and the rear Of the driver instead of random tuning that kinda smears together in HR wizard slider functions or the common bass reflex BP6 @ 2:1 spacing? Once you find a crossectional area that works for the TS parameters that doesn’t show excessive ringing @ resonator freqs or an oversized enclosures spikes @ the same it gets 💚💚
only odd numbered harmonics exist in qw pipes, so using them to your advantage, is going to get the most available out of the system. Otherwise, it’s missed the sweet spot and has obvious issues in Horn response that exposes this.
The devastator interesting, but it still has the same hiccups/damping issues? in the bandwith that you get if you’re trying to use different types of resonators or slightly inappropriately sized and length??
bottom example has issues, the top two are simple and ‘perfect’ examples that merely need fine-tuning to be the most they can possibly be
http://www.fonema.se/qpipe/qpipe.ht...sQUij2-feN_TtdRrty7IfqV-jacY996mHXJwUYF2DfyEg
only odd numbered harmonics exist in qw pipes, so using them to your advantage, is going to get the most available out of the system. Otherwise, it’s missed the sweet spot and has obvious issues in Horn response that exposes this.
The devastator interesting, but it still has the same hiccups/damping issues? in the bandwith that you get if you’re trying to use different types of resonators or slightly inappropriately sized and length??
bottom example has issues, the top two are simple and ‘perfect’ examples that merely need fine-tuning to be the most they can possibly be
http://www.fonema.se/qpipe/qpipe.ht...sQUij2-feN_TtdRrty7IfqV-jacY996mHXJwUYF2DfyEg
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Effin interesting read about the Q in pipe resonators. But that's theory, how to implement that in the real wood sub cabinet world!!!☹️
Start here(??) , these little examples work in anything (great TS parameters and motor force on a small SD ). Either the driver is at the pressure/velocity node for the next harmonic in that pipe or the exit is. Both of these attack the same thing, but one of them has an incredible amount of gain ‘perfectly aligned in phase’ because it’s using both sides of the driver intentionally clocked together instead of 180° out at that frequency.
A bit of dampening material and you’re on your way…..💚💚🤘🏻🤘🏻
move the drivers down from the closed end but KEEP the 3:1 relationship already (240/80cm ) there always!!
A bit of dampening material and you’re on your way…..💚💚🤘🏻🤘🏻
move the drivers down from the closed end but KEEP the 3:1 relationship already (240/80cm ) there always!!
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https://www.parts-express.com/Dayto...-Cone-Midbass-Woofer-8-Ohm-295-416?quantity=1
crash test dummies that do good work!😁
I have a short video showing a 3-D ‘cad’ model of that box, but it won’t post in this forum.. FB messeger or …. Allows this however
crash test dummies that do good work!😁
I have a short video showing a 3-D ‘cad’ model of that box, but it won’t post in this forum.. FB messeger or …. Allows this however
