Design a TRANSMISSION LINE Enclosure with LTspice

[@wrongIQ]

For some reason mac version ofthis software does not work the way you show. Everything is more or less the same in terms of interface, but it doesn't do the graph when you press "run". Only empty black window appears

[@Elliott-Designs]

Oh, that doesn't sound great 😕. Unfortunately I don't have a Mac myself. Sounds like an LTSpice problem more than the add-on itself SpicyTL. Might be worth reaching out on an LTSpice thread you can find on electronics forums. Sorry I couldn't be more help

[@wrongIQ]

@@Elliott-Designs oh... Don't worry! I've mentioned it to let your viewers know about the issue.

[@Elliott-Designs]

@@wrongIQ Thank you for letting everyone know! I've been sure to pin your comment. If you find a solution at some point, it would be great if you could share it 👍

[@Toid]

It is amazing how much of a change adding that fiber made.

[@Elliott-Designs]

It certainly is! I'm currently planning a several part video series where I'll be designing and testing a modular micro transmission line system that I can then use to see how accurate the simulations are! A few of these tests will be with the mineral wool to see how accurate the prediction from the program is, and how I can refine those programs to more closely represent the results I get from my mineral wool filling if needed!

[@joesapereira5539]

@@Elliott-Designs Interesting video. Looking forward to the follow up.

[@Elliott-Designs]

@@joesapereira5539 I'm glad you liked it, thank you! Planning on redoing this and splitting it into parts. Anything in particular you want to see done better, or more clarification on?

[@Elliott-Designs]

Side note: The differences between ported and transmission line loudspeakers are a little blurred, although there is a 12db/octave roll-off until our high pass filter (as one would get with a transmission line). It is also suggested by many that the difference between ported and transmission line enclosures is that a ported enclosure has a build up of pressure behind the cone (as with an acoustic suspension type sealed enclosure). Due to the thin nature of the port section on this design, it could be argued it is ported. However in my opinion this enclosure rather acts more like a mass loaded transmission line enclosure, since for that pressure differential to exist; a significantly large volume needs to be present to act as a resonance chamber, although that kind of chamber appears to exist in this design, it is my opinion it more acts as a wider port section of the transmission line that that has a stepdown in cross sectional area to the circular port.

[@Elliott-Designs]

Whether you believe it to be ported or transmission line of enclosure type, the importance of this video is reducing those upper frequency resonances through simulation of the internal geometry of the cabinet, since in most programs this isn't taken into account. P.s. The topic of it being transmission line or ported hasn't actually come up yet, I just preemptively commented about it as I believe it may be a point of contention due to the fine line between the two enclosure definitions.

[@Elliott-Designs]

Hope you enjoy the video! If there are any question you have for me, feel free to ask them, I'll be putting the answers to the good ones in a short video if there are enough of them! 😉

[@lio1234234]

Just gonna put this here for SEO 😂

[@Toid]

I have been waiting for this!! !

[@Elliott-Designs]

Thanks Nick!

[@philiptalbert458]

This is exactly what I was looking for, thanks!

[@Elliott-Designs]

I'm glad I could provide!

[@Wtf95]

Could you add a component to LTSpice for a room's property of raising low frequencies?

[@Elliott-Designs]

I did not make this add-on for LTSpice, nor make LTSpice itself, but you can fairly easily approximate a room's low frequency gain, much easier than having to put it into the program too. Take the longest dimension of the room and multiply it by two. This is the wavelength of the frequency where room gain will start (approximately). E.g. Starting frequency = speed of sound / (2*L). Where L is length in metres. For a perfectly sealed room this will continue with a trend of 12dB/Oct all the way down to 0 Hz. It is likely the slope will be less though, since this is under ideal circumstances. You also then have boundary gain. Have it next to one wall? Assume +3dB. Have it next to a wall and the floor, +6dB. In the corner of a room on the floor, +9dB. Again, these are all approximations. But I hope they help.

[@EngineeringEssentials]

Great tool! Thank you.

[@Elliott-Designs]

Glad you liked it! Not so many are aware of it, which made it the main reason for me wanting to make this video.

[@EngineeringEssentials]

@@Elliott-Designs I wonder if horn-loaded speaker simulation is possible with this software?

[@Elliott-Designs]

@@EngineeringEssentials it certainly is! You use the exact same principles and use an increasing cross-sectional area instead of a decreasing one. The only thing is that the approximation isn't as accurate at high frequencies since different geometries make more of a difference (e.g. square Vs circular, or truncated cone Vs truncated pyramid)

[@Elliott-Designs]

@@EngineeringEssentials To see those higher frequencies on the graph you can change the values in the area above driver specifications, it's named "analysis directives"

[@arvindambari]

👍💯

[@Elliott-Designs]

Thanks!

[@ZegaracRobert]

Beautiful, thank you for presentation, i was not aware of this tool, this seems like way better sym solution compared to one i have used so far (>>hornresp for TL/horn

[@Elliott-Designs]

I'm glad you liked it, I totally agree, this program is better for transmission lines purely for the fact that you can get excursion and velocity estimates unlike with hornresp, as for sealed it's better than winISD since you see resonances that 'reflect back through' the cone. If you can use hornresp, I think it's still better for horns due to the fact you can change the flare rate (exponential, etc), and Xsim is definitely the best for passive crossovers since you can use driver's impedance graphs. As for the chart colouring, sorry about that, I've only ever used LTspice with the SpicyTL plugin and not for any other reasons (mechanical engineering student), and because of that, I had absolutely no idea about plot lines. Sorry you struggled to see them. In future videos I'll be zooming in so it shouldn't be an issue anyways, I use these programs on a 55" screen so I usually don't think about how difficult it might be to see on a small screen. Either way, glad you enjoyed the video and I hope I've earned your subscription 😊