Keystone Sub Using 18, 15, & 12 Inch Speakers

5) There are many that complain about resonant behavior, but a 1/4 wave resonator cabinet won't work without it.

But you can push those unwanted resonances way out of the cabinet's intended passband so their audible impact is noticeably less, hence my interest in offset slot-loaded tapered TLs. Efficiency is a bit lower than a THs, but box size requirements are also lower, and out of band resonances can be pushed an octave above typical cabinet passband (~100 Hz) and they are also lower in level compared to the passband. Terminating the TL with a slot results in an Fb that's lower than a vented box of the same net volume (and the extra internal panels double as bracing), and the use of a slot instead of a full taper allows some flexibility in locating the offset to obtain the best results when the TL is folded up into a box.

An alternative approach is to design and build the TH using the process I outlined in this thread: Ooh looky - a TH that does from ~42Hz-500Hz +/-3dB

It does result in a slightly larger box though. I'm considering a redesign of my POC3 build to incorporate the larger S1-S2 volume to see if the results to match the sims.
 
Weltersys, it seems that all your discussions about the sensitivity graph on Danley's TH118 being 3 dB higher than it should, made them measure it again and it seems now that they have changed it. Cheers
Funny, the 2.83V/4 ohm "sensitivity" is 105 in the Architect/Engineer Specs, while it still is 108 in the "key features" area of the spec sheet.
Same mistake in the larger TH118XL specs. The TH118XL has about +3dB more output at 30Hz than the current TH118 (but less than the old TH118 measurement...)

Sometime around May 2018 they had updated the TH118 impedance chart (the 18Sound driver in the original TH118 had an impedance minima of 3 ohms)without changing the frequency response chart. Oddly, the lower impedance minima somehow went up from around 28 to 35 Hz.
No impedance charts were included in the current TH118 or TH118XL spec sheets, but the frequency response has been re-measured, probably when they noticed the previous TH118 appeared more "sensitive" than the larger TH118XL.
 
Funny, the 2.83V/4 ohm "sensitivity" is 105 in the Architect/Engineer Specs, while it still is 108 in the "key features" area of the spec sheet.

The FR graph for the TH118 seems to show it hitting around 108dB/2.83V/1M at just over 100 Hz. Between 50 to 100 Hz, it's around 105dB/2.83V/1M, and slopes off below that.


Sometime around May 2018 they had updated the TH118 impedance chart (the 18Sound driver in the original TH118 had an impedance minima of 3 ohms)without changing the frequency response chart. Oddly, the lower impedance minima somehow went up from around 28 to 35 Hz.

Now THAT I'm more interested in. I remember having a lot of discussion with JAG over that, him insisting that the minor changes in the TH118 compared to the TH115 of the same dimensions is what caused the lowest resonance frequency to drop to 28 Hz, and me responding that there was no way those minor changes could have made such a significant difference in the resonance point.

https://www.danleysoundlabs.com/danley/wp-content/uploads/2018/06/TH118-Specs-V2.0-1.pdf
 
I remember having a lot of discussion with JAG over that, him insisting that the minor changes in the TH118 compared to the TH115 of the same dimensions is what caused the lowest resonance frequency to drop to 28 Hz, and me responding that there was no way those minor changes could have made such a significant difference in the resonance point.
The LF impedance response of the BC18SW115-4 TH-118 appears to have changed back to being more similar to the TH-115 in the more recent (bottom chart) measurement, compared to the older 18 Sound loaded TH-118 (center chart).
 

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The LF impedance response of the BC18SW115-4 TH-118 appears to have changed back to being more similar to the TH-115 in the more recent (bottom chart) measurement, compared to the older 18 Sound loaded TH-118 (center chart).
The first graph for the TH118 seems just shifted 10 hz lower compared to the second. It could have been a computing error.
 
May you please do a final updated release? about Keystones

Oliver,

The corrections you made in the plans in Post # 85 (Drawing Correction #1) look good, nice job, thanks again.

Only difference of note is the bottom of the Keystone exit is 12.75 inch as built (323.85 mm), not 12.5 inch.

The difference of 1/4 inch there is not a concern.

The Keystone exit should be rounded over both sides.

Also, the braces are important, anyone attempting to build a similar cabinet should refer to the pictures in post #63.

Art Welter


May you please do a final updated release? about Keystones cab plan, corrections and cut sheet? Thannks in advance
 
May you please do a final updated release? about Keystones cab plan, corrections and cut sheet? Thannks in advance
As stated in post #1, corrected plans are available in post # 487, including parts layout, thanks to NEO Dan, with the exception that the bottom of part "F" is 89 degrees, the front of "G" is a 5 degree angle, the back of "G" is 3 degrees as shown in post #478.

That's as final as it's likely to ever be ;^).
 
As stated in post #1, corrected plans are available in post # 487, including parts layout, thanks to NEO Dan, with the exception that the bottom of part "F" is 89 degrees, the front of "G" is a 5 degree angle, the back of "G" is 3 degrees as shown in post #478.

That's as final as it's likely to ever be ;^).

Will these work with PD 186 version 1 18" woofers. (Fs 27, Qts.31,Qes .32 Vas 353ltrs, Mms 184 grm Bl 23 Tm, Xmax 10.5mm, Re 5.5, Sd 1150)

I am not looking for concert level bass just to move some air inside venues DJ work 30'x60' wooden dance floor a pair with BFM Omni 12 Tallboy's. I also have a Crest 7001 495w per channel 8ohm. For mobile DJ work only. Thanks:)