Keystone Sub Using 18, 15, & 12 Inch Speakers

A couple years ago I built an end firing TH that ended up tuned a bit lower than I had planned for @ ~28 Hz so I closed up the end and gave it a keystone exit that would still allow the driver to be installed, it got the tuning up to 30.5 Hz and worked out quite well.

IMG_0604.jpg~original
 
28Hz end fire TH

A couple years ago I built an end firing TH that ended up tuned a bit lower than I had planned for @ ~28 Hz,
so I closed up the end and gave it a keystone exit that would still allow the driver to be installed, it got the tuning up to 30.5 Hz and worked out quite well.
IMG_0604.jpg~original

Hi there D: Questions: what was the Fs for the driver and was there any partial end closure on the TH? This looks like a smallish TH that would work well for a home system and I'd like to use your folding for a similar 27 or 28 Hz TH that I'll simulate for a different driver.
...regards, Michael
 
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Awesome, Dan. Much different sound signature vs SS15/TH-18 style firing?

The sound is a bit different, IMO the signature followed with the changes comparatively.

Hi there D: Questions: what was the Fs for the driver and was there any partial end closure on the TH? This looks like a smallish TH that would work well for a home system and I'd like to use your folding for a similar 27 or 28 Hz TH that I'll simulate for a different driver.
...regards, Michael

It's a 15" car audio with driver relatively high FS (@39 Hz)and comparative horsepower to the 18SW115-4. Unfortunately it looks like the driver has been changed so I'd have to withhold my recommendation unless I can get one to measure. This was cooked up specifically for outdoor movies/music type duty.

XFL15TH.png~original
 
15" TH:
The 10 Hz lower FB and small peak at the bottom really lend a Hi-Fi quality to the sound, the lower FB also limits how high you can go with the LPF but the standard 80 Hz AVR LPF is fine with this setup. A good match for a 1kW RMS amp.

TH18
18SW115-4 on the other hand is a monster that will KICK HARD when fed appropriately, imagine standing in front of the box and trying to figure out what's actually moving, your toes, your shoes, or the concrete slab you are standing on - it's 89 octane vs top fuel in the input power department.

I don't have a preference, it's more of a choice of tool or weapon situation. Don't bring a knife to a gunfight.
 
Sorry, just meant the sound signature due to a different folding, SS15/TH18 style vs simpler Keystone style, if you had any two of similar size, output levels and fb to directly compare.

OK, here is a better example then. These two have very similar FB and are very much the same sound while having totally different folds, using the same amount of material - 2 sheets.

DSCN4635.jpg~original
 
Awesome. Are they both THs? One of them looks like it could be a FLH. What is the driver's orientation in the far enclosure? And if they're both THs, are there any notable differences in their sound characteristics?

I'm attempting to gather an idea whether or not a different folding from the same HR info will result a different audial experience. And if the driver facing out (like in the Keystone) adds notable output/tonal differences vs the driver facing more toward the floor, not directly toward the listener.

I'd like to hear your (and others') opinions from real world experience(s).
 
I think the sound correlates with the measurements, if the folds closely follow the model and the measurements also corroborate the sound will be the same. That said the fold will definitely influence the measurements, impedance measurements in particular are a great diagnostic tool IMO. This is the human equivalent of a dog chasing it's tail.:rolleyes:

It's a TH too, here's the intent, a 6' tall stack of FUN:

Stack25.jpg~original