I have a pair of 3WC with SB23NRXS45-8 bass elements. I am really happy with these speakers overall except for the bass (it is not all bad but I think it could be improved). I attribute the weaknesses to the BR design (but I might be wrong). I prefer the sound from a sealed enclosure and I would like to convert my 3WC to fully passive XO. I would therefor like to try a transmission line arrangement for some added efficiency (compared to going sealed).
I do not have access to the legendary spreadsheets by Martin J. King so I have made my initial simulations with HornResp. I would like to keep the enclosure as compact as possible and therefor the line as short as possible. I started out with a MLTL but it looks as if a tapered TL might be as good. HornResp is very capable but not the most intuitive simulator and I have a really hard time to dial in the optimum values for S0, SL, line length and especially the driver offset. I would therefor value second opinions from the ones used to simulate and build TL speakers (this will be my first TL build). What would be a good TL for the SB23NRXS45-8?
I do not have access to the legendary spreadsheets by Martin J. King so I have made my initial simulations with HornResp. I would like to keep the enclosure as compact as possible and therefor the line as short as possible. I started out with a MLTL but it looks as if a tapered TL might be as good. HornResp is very capable but not the most intuitive simulator and I have a really hard time to dial in the optimum values for S0, SL, line length and especially the driver offset. I would therefor value second opinions from the ones used to simulate and build TL speakers (this will be my first TL build). What would be a good TL for the SB23NRXS45-8?
How about an article by the legendary George Augspurger http://diyaudioprojects.com/Technical/Papers/Loudspeakers-on-Damped-Pipes.pdf
Thanks AllenB, I dont think I got a copy of this paper but I have read other material based on it. My end result will be a combination of figure 9; a, b, d and e. I have used similar tables as Table 2 (and 3) to come up with a starting point in HornResp (I will check them again against the tables in this paper). The problem I have with HornResp is the lack of visual resolution. I would like high resolution graphs with the option to zoom in and compare different input parameters.
Hmmm, reading my own writing just gave me an idea. There is an "Export SPL and Phase" option in the Acoustical Power window. I guess I could export, preprocess the exported file and import it into another application with the capabilities I need. A bit of a cumbersome workaround but doable...
It is quite easy (and powerful) to import the simulated response from Hornresp into VituixCAD for visualization, further measurement and manipulation. I have described how it is done in a post on my blog:
Using Hornresp with VituixCAD
Ps. I am still interested in simulations and suggestions for optimum TL parameters for SB23NRXS45-8.
Using Hornresp with VituixCAD
Ps. I am still interested in simulations and suggestions for optimum TL parameters for SB23NRXS45-8.
Below is a photo of my Sonatello 3-way design/build that used your SB woofers in a 25:1 tapered TL.
Paul
Paul
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I love your designs Paul! Great craftsmanship and they got a nice retro feel to them, great job!
Ps. I found the Sonatello build thread, I am reading through it right now...
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Using the loudspeaker wizard, set S2 to Auto by double clicking on the 'S2 Manual' label. Adjust L12 to change the driver offset without altering the overall length or taper. Press Crtl+C to capture current results, and Ctrl+V to view captured results as a light green trace. Press the Esc key to hide displayed captured results.
For a given driver, it should be possible to optimise a TL design in Hornresp in a few minutes.
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OMG, thanks David. I knew everything except the cut and paste -> green trace, brilliant! The loudspeaker wizard is great but it would be great with a higher resolution graph window...