Just my 2c:
I find it a bit strange that nobody mentions transmission lines, or better say, MLTL's. A long pipe with the driver on top could easily be tuned to be a sort of MLTL, so you can get enough bass extension with one driver, (that would work from 40-400hz for example), then Fr on top. I was playing with some pipes and built something that could be called "el-cheapo" Lx mini. I used four 4" automotive drivers, three feet long pipe with the port on bottom. For the money invested, it is the best sounding speker ever
I find it a bit strange that nobody mentions transmission lines, or better say, MLTL's. A long pipe with the driver on top could easily be tuned to be a sort of MLTL, so you can get enough bass extension with one driver, (that would work from 40-400hz for example), then Fr on top. I was playing with some pipes and built something that could be called "el-cheapo" Lx mini. I used four 4" automotive drivers, three feet long pipe with the port on bottom. For the money invested, it is the best sounding speker ever
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Thanks for feed back Vix , you just have proofed superiority of such design.
What Fr driver is?
I bet sound really god and in combination with industrial look it has contrasting psychobiological effect.
Same thing like ...I cant believe my ears what I'm hearing from such looking speaker !!! Such sound should came only from mirror shiny nice boxes !!!
What about MLTL`s ,do you have same ideas ,how to integrate those ?
Please tell more.
What Fr driver is?
I bet sound really god and in combination with industrial look it has contrasting psychobiological effect.
Same thing like ...I cant believe my ears what I'm hearing from such looking speaker !!! Such sound should came only from mirror shiny nice boxes !!!
What about MLTL`s ,do you have same ideas ,how to integrate those ?
Please tell more.
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Hi,
Speakers are just 4", 4 ohms speakers, the one on the pipe is Sony, the other one is no name OEM which I got for free. The pipe is a something like Sonotube,in fact it is a carpet roll, I got that one for free as well
Google for: Mass Loaded Transmission Lines
And : Pensil speaker projects.
This pipe is a sort of "Pensil" but the driver is facing upwards. (Google "Pensil" speakers)
Mr. Linkwitz showed us what works. It is our homework to try out different combinations of the same basic design. It is very rewarding
Speakers are just 4", 4 ohms speakers, the one on the pipe is Sony, the other one is no name OEM which I got for free. The pipe is a something like Sonotube,in fact it is a carpet roll, I got that one for free as well
Google for: Mass Loaded Transmission Lines
And : Pensil speaker projects.
This pipe is a sort of "Pensil" but the driver is facing upwards. (Google "Pensil" speakers)
Mr. Linkwitz showed us what works. It is our homework to try out different combinations of the same basic design. It is very rewarding
If you remove (short) the 0.47mH coil and use your active xover as you are currently, that will permit the usage as I suggested.
Later,
Wolf
Dear Wolf,
I would like to thank you for suggestion to go 2,5 way configuration, I'm convinced this it is right way to do.
Such set up like LXmini ,I deeply believe, will benefit and a lot from 2,5 way configuration.
Personally I'm absolute idiot when it came to "hard" crossovers( never liked those).
Please take a look at drawing, is should be like this ?
If not can you make quick sketch, please.
I would like to thank you for suggestion to go 2,5 way configuration, I'm convinced this it is right way to do.
Such set up like LXmini ,I deeply believe, will benefit and a lot from 2,5 way configuration.
Personally I'm absolute idiot when it came to "hard" crossovers( never liked those).
Please take a look at drawing, is should be like this ?
If not can you make quick sketch, please.
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Your previous image is correct in post #50. The photo you just posted is just another way of doing it, but not as beneficial in your case. The benefit with the 0.5 woofer is in it being in parallel with the 1st unit, and getting the same phase result as the first woofer, and the same upper xover point and blemish remedies.
Basically, both woofers will do the bass sector, as both are rolling off the upper end. Since the rolloff starts lower on the secondary unit, you can use it to gain back for Baffle Step response if necessary. You may have to play with the value of the coil to find the best compromise.
Some other info- as the woofers re in parallel in the bass, that is +6dB in that range over a single. The upper woofer will be mating the widebander, and the lower one will rolloff where it won't have to. If you think point-source, this is better in terms of wavelengths. The wavelength where the lower rolls off will be a lot longer, and easy to sum with the upper woofer. Since it will be on the bottom, it may also get some boundary reinforcement from the floor, giving you more bass than you might need. The other thing is that Omni-radiation actually eliminates the need for BSC, but introduces greater off-axis responses.
Basically, both woofers will do the bass sector, as both are rolling off the upper end. Since the rolloff starts lower on the secondary unit, you can use it to gain back for Baffle Step response if necessary. You may have to play with the value of the coil to find the best compromise.
Some other info- as the woofers re in parallel in the bass, that is +6dB in that range over a single. The upper woofer will be mating the widebander, and the lower one will rolloff where it won't have to. If you think point-source, this is better in terms of wavelengths. The wavelength where the lower rolls off will be a lot longer, and easy to sum with the upper woofer. Since it will be on the bottom, it may also get some boundary reinforcement from the floor, giving you more bass than you might need. The other thing is that Omni-radiation actually eliminates the need for BSC, but introduces greater off-axis responses.
Wolf, I'm reading your comments and seeing in my eyes only Christmas presents , so much benefits over original design is to gain from 2,5 way set up, incorporating it to LX mini concept. Cant wait to build 2,5 way LX mini! But all this - after Christmas.
Choice of drivers...is a secondary pain in my neck.... same how I'm leaning to this:
- Rebuild my exiting speaker with 25 litter pipe volume with incorporating second woofer. 4x Scan-Speaks 22W/8534G000, should do a job.
Those will move 960 cm^2 air !!!! 4x 240 cm^2 ( piston area) = 960 cm^2
This guy was imprest with 22W/8534G00 as well.
Choice of drivers...is a secondary pain in my neck.... same how I'm leaning to this:
- Rebuild my exiting speaker with 25 litter pipe volume with incorporating second woofer. 4x Scan-Speaks 22W/8534G000, should do a job.
Those will move 960 cm^2 air !!!! 4x 240 cm^2 ( piston area) = 960 cm^2
This guy was imprest with 22W/8534G00 as well.
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Regards horizontal drivers, it's worth considering suspension stiffness and resting cone displacement as for example Linkwitz did here: Pluto + subwoofer
I have difficulty to understand (I'm sure this is because me and my language skills) Mr.Linkwitz writing :
" The 12" driver is capable of 4 dB higher excursion limited SPL because of its larger piston area."
Peerless 12" SLS 830669 has half Space Sensitivity 2.83V/1m-89.8 dB and Peerless 10" 830668 has half Space Sensitivity 2.83V/1m-87.9 dB......
Using my special arithmetical skills I'm getting 1,9 dB different but not 4 dB.
Self sentences contains two statements :
1 statement: " The 12" driver is capable of 4 dB higher excursion...." all this is fine and sentences could end right there.
2 statement :" limited SPL because of its larger piston area" what that saying to me is as a speaker with larger piston area I would have lower SPL (sound pressure level )....Is such statement is true ?
What makes those two statements to stay in the same sentence ?
Or must understand like " The 12" driver is capable of 4 dB higher excursion and that limits SPL because of its larger piston area ?"
" The 12" driver is capable of 4 dB higher excursion limited SPL because of its larger piston area."
Peerless 12" SLS 830669 has half Space Sensitivity 2.83V/1m-89.8 dB and Peerless 10" 830668 has half Space Sensitivity 2.83V/1m-87.9 dB......
Using my special arithmetical skills I'm getting 1,9 dB different but not 4 dB.
Self sentences contains two statements :
1 statement: " The 12" driver is capable of 4 dB higher excursion...." all this is fine and sentences could end right there.
2 statement :" limited SPL because of its larger piston area" what that saying to me is as a speaker with larger piston area I would have lower SPL (sound pressure level )....Is such statement is true ?
What makes those two statements to stay in the same sentence ?
Or must understand like " The 12" driver is capable of 4 dB higher excursion and that limits SPL because of its larger piston area ?"
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Considering suspension stiffness.
Guys,please correct me if I understood wrong....Mr. Linkwitz was interested how speakers driver will react to stiffness of material used for his subwoofer box and vice versa ?
And this woofer having LR4 crossover at 100 Hz.
Our situation is quite different:
1.In a project we are having two woofers in one air tight (not quite true because it is small hole 1,5 mm in Ø drilled in wooden bottom plate) pipe.
2.Our box is cylindrical pipe ( stiff as a hell) heavy duty 225 mm.(ca.9") in O.D.Ø black mixer of PVC -epoxy and stones from Everest mountain . A nuclear explosion will not affected it !
Mine question is,so how we should be wary about our pipe affecting in negative way our woofers ?
In what negative ways our woofers could be affected by our nuclear proof pipe ?
Thank you all for participating
Guys,please correct me if I understood wrong....Mr. Linkwitz was interested how speakers driver will react to stiffness of material used for his subwoofer box and vice versa ?
And this woofer having LR4 crossover at 100 Hz.
Our situation is quite different:
1.In a project we are having two woofers in one air tight (not quite true because it is small hole 1,5 mm in Ø drilled in wooden bottom plate) pipe.
2.Our box is cylindrical pipe ( stiff as a hell) heavy duty 225 mm.(ca.9") in O.D.Ø black mixer of PVC -epoxy and stones from Everest mountain . A nuclear explosion will not affected it !
Mine question is,so how we should be wary about our pipe affecting in negative way our woofers ?
In what negative ways our woofers could be affected by our nuclear proof pipe ?
Thank you all for participating
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Thank you scottjoplin,
I see...how wrong I was ...ok,we still have time in our life to correct that.
Right know at this moment installing windows office,because Mr. Linkwitz has xls files on a subject. Lets see how I will handle bunch of numbers.
Dear scottjoplin, if you don't have feeling as you are wasting your time , please expand subject on Mr. Linkwitz research off course in your own words ( you are always perfectly clear what you would like to say about subject , deeply appreciate that ) and in practical therms. Thank you
I see...how wrong I was ...ok,we still have time in our life to correct that.
Right know at this moment installing windows office,because Mr. Linkwitz has xls files on a subject. Lets see how I will handle bunch of numbers.
Dear scottjoplin, if you don't have feeling as you are wasting your time , please expand subject on Mr. Linkwitz research off course in your own words ( you are always perfectly clear what you would like to say about subject , deeply appreciate that ) and in practical therms. Thank you
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