Hello
I recently simulated and built a tapered transmission line for a Beyma 8br/40n driver. I simulated in Lenard Audio Transmission Line and also in Hornresp, the simulations show good results.
Lenard audio
Hornresp
Measured Speaker TS parameters
The simulated enclosure
I folded the box to make it more compact like this
Then, the actual construction
could the extended sidewalls for the port opening play a role in how is the bass distributed in room?
I placed the speaker in corners and also away from the wall. In two different sized rooms. The bass is too much in specific point of rooms, that I could understand but in the rest of the room the bass is lacking a lot. The feeling is as if it was "out of phase". The speaker is moving, the curtains, the tv and the wall is shaking, resonating but almost no bass in front of the speaker.
I have not stuffed the TL because that should change how i works over 100hz, at the moment I am analizig 30-60hz
I have had other MLTL speakers and BR speakers in these rooms and they play fine.
Please share an idea with me on this
I recently simulated and built a tapered transmission line for a Beyma 8br/40n driver. I simulated in Lenard Audio Transmission Line and also in Hornresp, the simulations show good results.
Lenard audio
Hornresp
Measured Speaker TS parameters
The simulated enclosure
I folded the box to make it more compact like this
Then, the actual construction
could the extended sidewalls for the port opening play a role in how is the bass distributed in room?
I placed the speaker in corners and also away from the wall. In two different sized rooms. The bass is too much in specific point of rooms, that I could understand but in the rest of the room the bass is lacking a lot. The feeling is as if it was "out of phase". The speaker is moving, the curtains, the tv and the wall is shaking, resonating but almost no bass in front of the speaker.
I have not stuffed the TL because that should change how i works over 100hz, at the moment I am analizig 30-60hz
I have had other MLTL speakers and BR speakers in these rooms and they play fine.
Please share an idea with me on this
Nice work! I have similar experience with how powerful bass can be with a tapered TL too. Stuffing is important and should be done in conjunction with impedance sweeps - increase untill the measured double peak impedance is squashed and flattened to a what looks like a horned owls’ head. A single large bump with two small “ears”. This will decrease overall bass output but improves the group delay tremendously. It will help with the out of phase issues. You will still have plenty of deep tight and articulate bass.
A simulation in Akabak allows stuffing to be varied. Not sure if Leonard does this.
I made a small 5.25in PMC inspired TL and got huge bass and used quite a bit of stuffing.
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
A simulation in Akabak allows stuffing to be varied. Not sure if Leonard does this.
I made a small 5.25in PMC inspired TL and got huge bass and used quite a bit of stuffing.
Low-Cost PMC-inspired TL Monitor with DC130A and DC28F
Thats a good good feeling when someone says thumbs up 🙂
Sorry for the gigantic pictures, on Safari they appeared small.
This is what LA simulates the stuffing
zero stuffing impedance
1kg/m3
2kg/m3
How do you rate this synthetic synthepone for stuffing?
Friday I am going to get my hands on some good stuff - long fiber lambs wool
Sorry for the gigantic pictures, on Safari they appeared small.
This is what LA simulates the stuffing
zero stuffing impedance
1kg/m3
2kg/m3
How do you rate this synthetic synthepone for stuffing?
Friday I am going to get my hands on some good stuff - long fiber lambs wool
Akabak does not run on Win7 as far as I know but Hornresp with collaboration with LA and WinISD plus DATS, works
its sure a good looking cabinet. I'm used to larger speakers and an higher tuning so don't know what a good T-line might do - guess the room could have a large influence
here's what I get with hornresp and guessing 40cm from the speaker back to the exit (what distance is that in reality ?)
there's only a little polyfill in this sim - and more density in the first section than the second
here's what I get with hornresp and guessing 40cm from the speaker back to the exit (what distance is that in reality ?)
there's only a little polyfill in this sim - and more density in the first section than the second
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The simulation is accurate, Thank you
Lets see what tomorrow brings when I get lambs wool, hopefully it fixes the phase issues
Lets see what tomorrow brings when I get lambs wool, hopefully it fixes the phase issues
You can install a virtual machine to run Akabak in a WinXP environment from Win 7 or 10. That’s what I do.
The stuffing used inside a enclosure can increase the bass or decrease(dry box as used in pro audio), seems you do nothing to up the bass, this white foam in the photo dont will enlarge the bass, just reduce resonance a bit.
The best material to increase the bass I found so far is the usual brown car hood blanket 10mm, its used since ever by car audio guys to increase bass performance it real enlarge the bass at a low price.
But audiophiles and hi price speakers makers are unaware or dismiss this material, perhaps because it is not expensive enough.
For more tips see this topic:
How Treat Passively Peaky Fullrange Drivers
The best material to increase the bass I found so far is the usual brown car hood blanket 10mm, its used since ever by car audio guys to increase bass performance it real enlarge the bass at a low price.
But audiophiles and hi price speakers makers are unaware or dismiss this material, perhaps because it is not expensive enough.
For more tips see this topic:
How Treat Passively Peaky Fullrange Drivers
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Another good choice to line cabinets is reticulated melamine sponges, aka "Magic Erasers". Bag of 100 from China for $6 shipping included. Same as formerly patent protected BASF BASOTECT sound abatement foam.
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