This YT video popped up on my feed because of my interest in Karlson type speakers. The sub in the video intrigues me. The video describes the sub as "Peerless SLS 10" in TQWT enclosure".
I would think that the design could be reverse engineered from the visual and the driver specs. Anyone interested in posting some ideas for dimensions and possibly a frequency response sim? I think it is a little beyond my capabilities to do it for myself.
I would think that the design could be reverse engineered from the visual and the driver specs. Anyone interested in posting some ideas for dimensions and possibly a frequency response sim? I think it is a little beyond my capabilities to do it for myself.
Video unavailable 🙁 Regardless, yes it will work in various types of TQWT, though of course no clue without the video to know which one intrigued you. 😉 Anyway, the basics are no different than vented, so to the 1st approximation........
T/S max flat alignment:
Vented net volume (Vb) (L) = 20*72.9*0.55^3.3 = 202.75 L (Ft^3 = (Vb)/~28.31685) = 7.16 ft^3
Vented box tuning (Fb) (Hz) = 0.42*32.4*0.55^-0.96 = 24 Hz
F3 (Hz) = Fs*0.28*0.55^-1.4 = 21 Hz
So......... is this about the size or ??? with the understanding that smaller = less (sub) bass, though if hard up against a wall or in a corner it can be shrunk to suit.
T/S max flat alignment:
Vented net volume (Vb) (L) = 20*72.9*0.55^3.3 = 202.75 L (Ft^3 = (Vb)/~28.31685) = 7.16 ft^3
Vented box tuning (Fb) (Hz) = 0.42*32.4*0.55^-0.96 = 24 Hz
F3 (Hz) = Fs*0.28*0.55^-1.4 = 21 Hz
So......... is this about the size or ??? with the understanding that smaller = less (sub) bass, though if hard up against a wall or in a corner it can be shrunk to suit.
@GM, if you copy the video URL, it will open in an incognito window.
I've tried to show a thumbnail from the video, but the forum won't let me. Here's a link:
https://i.ytimg.com/vi/Vwgb1SHwkV8/maxresdefault.jpg
jeff
I've tried to show a thumbnail from the video, but the forum won't let me. Here's a link:
https://i.ytimg.com/vi/Vwgb1SHwkV8/maxresdefault.jpg
jeff
Ah! OK, it 'says' it's a Karlsonator, but appears to be a basic 'classic' 'Voigt' style pipe from the '30s that was all over the net back in the '90s and in general must be heavily stuffed to perform well.
Regardless, we can do much better performance wise nowadays using the specs I posted even if you want something similar looking and do you plan to corner load also?
Regardless, we can do much better performance wise nowadays using the specs I posted even if you want something similar looking and do you plan to corner load also?
Hornresp simmed ~84" high 202.75 L net, critically damped 24 Hz ML-TQWT = 105 dB/20 Hz/2pi/45 W driver offset ~centered in a ~ 8 ft ceiling height.
It was honestly about the sound on the video. I know, I know... But hear me out. I really like the sound on the video and have not heard really any subwoofers that sounded good to me. Most I have heard sound like the guy in the car two cars ahead at the light where you can only hear non-musical booms. I know the videos aren't the best representation, but I also don't think the youtube codec is making it sound better. Also, it seems very likely that the guy fiddled with the tracks to make them bass heavy, as it looks like that is his thing based on the other videos he posted.
I assumed that the TQWT would be responsible for the pleasant bass presentation. If there are examples of other subs to consider I'd love to see them. I would be using it up against the wall, but not 8' ceiling. It would be 8' vaulted ceiling.
So 84" high and 202.75 L volume. Are there any pointers on how to set the profile? What is the measure of the acute angle?
Well, the baffle terminates to a point at the top, so it depends on the WxD dims.
7.16 ft^3*1728" = 12372.48"^2/84" = 147.291"^2 = sqrt(147.291) = 12.14" i.d. square base or whatever rectangular base allows the driver to physically fit at 28.74"/73 cm i.d. up vertically from the bottom plate.
Of course this is just a sim, so may want to draw to scale to make sure the driver will fit and increase base area if need be as any extra net Vb within reason just makes for more LF efficiency.
202.75 L*1000 = 202750 cm^3/(84*2.54) = 950.272 cm^2 = sqrt(950.272) = 30.826 cm/2.54 = 12.14" i.d.
7.16 ft^3*1728" = 12372.48"^2/84" = 147.291"^2 = sqrt(147.291) = 12.14" i.d. square base or whatever rectangular base allows the driver to physically fit at 28.74"/73 cm i.d. up vertically from the bottom plate.
Of course this is just a sim, so may want to draw to scale to make sure the driver will fit and increase base area if need be as any extra net Vb within reason just makes for more LF efficiency.
202.75 L*1000 = 202750 cm^3/(84*2.54) = 950.272 cm^2 = sqrt(950.272) = 30.826 cm/2.54 = 12.14" i.d.
In re-reading this post carefully - it seems like you are suggesting that a 7.16 ft^3 vented box would perform just as well. Is this inference correct? If I am barking up the wrong tree with the TQWT/ ML-TQWT then please feel free to tell me plainly.
I would be interested in opinions on the options for a sub that sounds musical and can get fairly low (not really sure what the number is though - I would guess around 28hz would be sufficient). My goal would be a sub that can cover up to 200 hz for use with DMLs or crossed lower ~80 hz if used with other more traditional full range drivers.
If just wanting a subwoofer, yes, in that T/S theory box loading is limited to Fs - Fhm/upper mass corner = 2*Fs/Qts'
(Qts'): (Qts) + any added series resistance (Rs)
Unless using tubes, Rs is normally < ~ 0.5 ohms for (sub) woofers, so most folks ignore it or use the pioneer's and the late Dr. Leach's Qes preference as I've done for personal use; this makes the Peerless SLS-P830668 box BW = ~32.4 - 109.8 Hz, not even (2) octaves (32.4*2^2 = 129.6 Hz), so at a glance the differences is primarily one of box shape to fit the needs of the app; but the math assumes that the box's acoustic air mass spring is one of uniform particle density, hence once it's stretched to a high enough aspect ratio, eigenmodes develop and depending on its shape can have either only odd harmonics or even and odd ones with the Voigt Pipe a closed cone.
From this we see that its odd harmonics pipe action will acoustically damp the driver and/or shorten a BR's vent for a given pipe area (Av) and/or allow a larger one for a given length and since there's no such thing as too much acoustic efficiency, just a point of diminishing returns with the latter originally the main performance reason for them, though nowadays with relatively tiny Vas spec drivers the norm, the shortened vent dominates.
All else equal; sonically, critically damping the BR's vent and/or box stuffing can achieve parity to mine and many folk's satisfaction, so your call as to which type best overall meets the needs of the app. 😉
(Qts'): (Qts) + any added series resistance (Rs)
Unless using tubes, Rs is normally < ~ 0.5 ohms for (sub) woofers, so most folks ignore it or use the pioneer's and the late Dr. Leach's Qes preference as I've done for personal use; this makes the Peerless SLS-P830668 box BW = ~32.4 - 109.8 Hz, not even (2) octaves (32.4*2^2 = 129.6 Hz), so at a glance the differences is primarily one of box shape to fit the needs of the app; but the math assumes that the box's acoustic air mass spring is one of uniform particle density, hence once it's stretched to a high enough aspect ratio, eigenmodes develop and depending on its shape can have either only odd harmonics or even and odd ones with the Voigt Pipe a closed cone.
From this we see that its odd harmonics pipe action will acoustically damp the driver and/or shorten a BR's vent for a given pipe area (Av) and/or allow a larger one for a given length and since there's no such thing as too much acoustic efficiency, just a point of diminishing returns with the latter originally the main performance reason for them, though nowadays with relatively tiny Vas spec drivers the norm, the shortened vent dominates.
All else equal; sonically, critically damping the BR's vent and/or box stuffing can achieve parity to mine and many folk's satisfaction, so your call as to which type best overall meets the needs of the app. 😉
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Yeah, when one designs based on the fundamentals of acoustics and not limited by size/shape, Mother Nature takes care of the rest. 😉
??? 20*Vas*Qts'^3.3, so Vas only dominates when it's high and/or Qts is low in vented and for sealed 'a' = Vas/Vb where a = (Qtc/Qts)^2 - 1 or are you referring to this:
Pg. 76: https://archive.org/details/HowToBuildSpeakerEnclosuresByAlexixBadmaieffDonDavis/page/n75/mode/2up
“A nagging question in the design stage of any enclosure of this type is "How large shall it be?” It was pointed out earlier that the enclosure can be too large or too small for proper bass-reflex action. This implies that an optimum volume exists and indeed it does. This optimum volume does not depend upon the size of the speaker nor its resonant frequency per se but rather on the ratio of enclosure air stiffness to the speaker cone suspension stiffness. This optimum ratio is 1.44 or, looking at it another way, the speaker resonant frequency in the enclosure before porting should be 1.56 times the free-air resonance of the speaker. This size enclosure, when properly tuned, yields at the same time the most extended low-frequency response and a transient response with subjectively unnoticeable hangover, assuming sufficient damping exists. Compared to the entirely closed cabinet, the half-power point (3 db down) occurs at 0.7 times the closed cabinet speaker resonance for an extension of one-half octave."
Pg. 76: https://archive.org/details/HowToBuildSpeakerEnclosuresByAlexixBadmaieffDonDavis/page/n75/mode/2up
“A nagging question in the design stage of any enclosure of this type is "How large shall it be?” It was pointed out earlier that the enclosure can be too large or too small for proper bass-reflex action. This implies that an optimum volume exists and indeed it does. This optimum volume does not depend upon the size of the speaker nor its resonant frequency per se but rather on the ratio of enclosure air stiffness to the speaker cone suspension stiffness. This optimum ratio is 1.44 or, looking at it another way, the speaker resonant frequency in the enclosure before porting should be 1.56 times the free-air resonance of the speaker. This size enclosure, when properly tuned, yields at the same time the most extended low-frequency response and a transient response with subjectively unnoticeable hangover, assuming sufficient damping exists. Compared to the entirely closed cabinet, the half-power point (3 db down) occurs at 0.7 times the closed cabinet speaker resonance for an extension of one-half octave."
???? I mean you can make a design and reverse engineer it to 'taste' same as I did to create the BIB pipe horn, so no 'relating' to other designs per se, i.e. if it works for you that's all that matters 😉 and if others like it enough might even get MJK to eventually 'rubber stamp' it 👍.
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@GM
I’m Still trying to make drivers with ‘small’ vas look decent in TL type designs that arent so small they’re just port/vent noise 😥
tweaking the ‘QL function‘ a bit helped find a happy place @ 12-15 or so (not so insanely ringy/spikey)instead of lossless. But ’10’ didn’t match (small room/car) measured
aLso, the LE and huge mms? Roll off the top end big time, and the cabin gain and/or null issues above 60 hz or so in the cabin (???) compound the issues In car audio drivers. 12” drivers with 20 liters of Vas and 400 mms…. 🙈
I’m Still trying to make drivers with ‘small’ vas look decent in TL type designs that arent so small they’re just port/vent noise 😥
tweaking the ‘QL function‘ a bit helped find a happy place @ 12-15 or so (not so insanely ringy/spikey)instead of lossless. But ’10’ didn’t match (small room/car) measured
aLso, the LE and huge mms? Roll off the top end big time, and the cabin gain and/or null issues above 60 hz or so in the cabin (???) compound the issues In car audio drivers. 12” drivers with 20 liters of Vas and 400 mms…. 🙈
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