Let's hope so! Outside of the Duelund concrete horn - which I've started modeling now - I'm also entertaining the idea of a rear-venting horn in the style of the Aveburys. Not with all the complex filtering and chambering mind you, but I feel like the form factor lends itself well to the Beta 8's since they seem to need a bit of space to comfortably play down to ~Fs.
And on that note, I have a question for the sages!
In speakers like the Frugel-horn and BiB, the driver is placed a ways down the horn, not too unlike a Voigt pipe -- What does this achieve? Is it still a true horn at that point, or does it rely on a different principle? Is there some ratio to consider?
As an added note, thank you all for being so helpful. It's been really fun so far (If a bit mind numbing) learning about and applying all of this.
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These are called tapped horns. The BIB is a Voigt, but requires specific placement to work right.
dave
These are called tapped horns. The BIB is a Voigt, but requires specific placement to work right.
??? This is a tapped horn, AKA 6th order bandpass (BP6).........so technically all others are just basically offset driver alignments.
??? This is a tapped horn, AKA 6th order bandpass (BP6).........so technically all others are just basically offset driver alignments.
👍 Yeah, combined with duct or cheap packing tape (my fave), great for prototyping and making inexpensive speakers using high Qts' drivers.
(Qts'): (Qts) + any added series resistance (Rs)
I found a really nice paper based packing tape. Same strength as normal packing tape (assuming you mean the brown plastic stuff), but it's made of the same paper used for corrugated cardboard. To claim it makes it pretty is a stretch, but it definitely makes for a more even appearance.
Understood.
OK, bad idea on my part if this is the first one--you have to be able to listen "around" and "through" that--which really only comes from experience. Still worth considering cardboard & tape, etc if you can, IMO, just for the process.
The rest sounds pretty normal--none of us want the extra 3 or 5 sub-hobbies, that's just how it happens 🙂
Absolutely. If anything it'll give me a good indication as to the size of them.
Ok. And the offset driver alignment achieves what, exactly? Does the space "above" the driver simply act as some sort of filter chamber? Is it important that the driver be placed asymmetrically along the horn, ruling out a symmetrical "dual path" horn? For example, the Duelund horn has a bit of internal volume ahead of (or below in this case) the driver.
Reason I'm asking is because I'm wondering whether something like the enclosure pictured below would work.
Not sure how to dimension the rear-venting area though. Assuming a 45 degree "radiation angle" of the volume, it seems to perform decently in Hornresp.
More reading but some of Martin’s TL and BLH papers have dealt with the function of offset drivers and tapering the line. http://www.quarter-wave.com/
Covered very well by Martin. Short version: offsetting the drivers causes changes in the wav etrain of harmonics and if you get it right you can almost fully kill the 1st unwanted harmonic without any damping.
dave
I think Dave means [single] tapped horn (another way of saying offset driver) as opposed to the DSL / Ultraflex type which being 6th order BP variations are technically double tapped.
Edit: reading back, this is starting to sound alarmingly like combat shooting techniques.
👍 😎 Yeah, assumed as much, but with all these acronyms nowadays, need to be well refined for all the 'newbies', lurkers these types of alignments are generating lately (still haven't got all the para-whatever down 'pat' as they seem to be some sort of virulent virus).
Not in an offset driver alignment; need to become as 'comfortable' with MJK's docs and attached resonance tutorials as many of us if wanting to make TL/horn design your cab alignment preference. 😉 Ditto this patent: http://www.xlrtechs.com/dbkeele.com...Preprint) - LF Horn Design Using TS Paras.pdf
http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/rescon.html#c1
http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/opecol.html#c1
http://hyperphysics.phy-astr.gsu.edu/hbase/Waves/clocol2.html#c1
The area between a BLH's closed end and driver is a low pass filter and between the driver, horn throat of a FLH.
Generally speaking, any curvature is a function of the horn's Fc relative to its in room boundary loading for best practical 'blend'.
Yeah, I realize that
So -- the rearmost curve is a cut-away that's meant to utilize the wall to extend the horn surface, essentially. Similar to the Aveburys.'Tis becoming increasingly clear
Nothing to it but to do it -- Think I've reached my upper limits for heuristics anyways..School has started back up now, so things are going to slow down for a bit. Went over the plans with my father during the weekend though, and he's equally curious about the Duelund horn, so modelling that will make up my free time for a while. Mainly aiming to unfold the horn and calculate the volumes to determine suitability for the Betas.
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NEVER MIND. Couldn't leave well enough alone, so modeled the "small" Duelund yesterday according to the available plans. Aside from minor deviations it came together fairly accurately (within ~0.5mm).
Simulated it in hornresp and the results are reasonable IMO. Fair bit more "comb"-y but with better bass extension. Grayed out response curve is the modified Dallas horn. Makes the decision a bit harder.
Simulated it in hornresp and the results are reasonable IMO. Fair bit more "comb"-y but with better bass extension. Grayed out response curve is the modified Dallas horn. Makes the decision a bit harder.