astrojet:
I see you have a unique room layout. It may be difficult but not impossible to get some good sound. It will require some trial and error. I would position your speakers on the short wall to start, where you indicate the green speakers. Horns would probably be your best bet since you would get less side wall reflections. A mid bass horn IMHO would be almost a necessity for the same reason. You could also put 2 slim tapped horns on the inside next to your main speakers.
Do you have future plans to put an equipment rack and or a flat tv on the wall between your speakers if you choose the short wall ?
I will presume the other room is not an option for your stereo system as it looks like it would be better.
I see you have a unique room layout. It may be difficult but not impossible to get some good sound. It will require some trial and error. I would position your speakers on the short wall to start, where you indicate the green speakers. Horns would probably be your best bet since you would get less side wall reflections. A mid bass horn IMHO would be almost a necessity for the same reason. You could also put 2 slim tapped horns on the inside next to your main speakers.
Do you have future plans to put an equipment rack and or a flat tv on the wall between your speakers if you choose the short wall ?
I will presume the other room is not an option for your stereo system as it looks like it would be better.
hottattoo, I wonder how physically close a mid-bass horn would need to be to my mid-horn to have a coherent wavetrain. I think I've seen guys talk about rules of thumb for inter-speaker spacing and shortest wavelengths -- in my case only a couple of cm for the compression tweeter.
Green speakers are where I've had the frugalhorns for the last 6 months. It is quite convenient that there are shelves at the blue locations so I can 'recess' the horns into the other room.
No TV. My wife and I spend what most people consider TV time in the evenings by listening to music and watching the ocean out the window. My amps and sources are currently parked up in the corner between the blue and green horns in the schematic. Once this woofer business is a little more under control, I'll probably try to build up a furniture-grade rack to house everything.
The fireplace room is the wife's piano room -- off limits for stereo kit.
tb46, stay tuned! Fun stuff. Hornresp is fired up and running. Should have a straw-man design in a day or two.
Green speakers are where I've had the frugalhorns for the last 6 months. It is quite convenient that there are shelves at the blue locations so I can 'recess' the horns into the other room.
No TV. My wife and I spend what most people consider TV time in the evenings by listening to music and watching the ocean out the window. My amps and sources are currently parked up in the corner between the blue and green horns in the schematic. Once this woofer business is a little more under control, I'll probably try to build up a furniture-grade rack to house everything.
The fireplace room is the wife's piano room -- off limits for stereo kit.
tb46, stay tuned! Fun stuff. Hornresp is fired up and running. Should have a straw-man design in a day or two.
simulation V1
Here is a first stab at shortening the offset MLTL and extending the high-w response in Hornresp. What does everyone think? Is the peak/trough at ~ 230 Hz deadly? Any ideas about how to flatten it out? is the ~ 1dB/octave negative slope from 50 Hz to 200 Hz troubling?
I'm a relative novice, so looking forward to advice from the likes of you experts!
Sorry for the metric units.
Thanks!
Here is a first stab at shortening the offset MLTL and extending the high-w response in Hornresp. What does everyone think? Is the peak/trough at ~ 230 Hz deadly? Any ideas about how to flatten it out? is the ~ 1dB/octave negative slope from 50 Hz to 200 Hz troubling?
I'm a relative novice, so looking forward to advice from the likes of you experts!
Sorry for the metric units.
Thanks!
I have listened to Dr. Bruce Edgar's full Titan system at his home for several hours and the speakers blended perfectly at about 14' listening distance. Do a search for pictures of this system. You should make yours close to the same size. Another similar system is by Volvotreter and John Inlow sound. I modeled my horn system to closely resemble the Cessaro Gama speaker which I consider the best speaker system available. Another site to check is DIY Sound Group for horns and waveguides. Once you listen to a PROPER horn system you will never go back to a " box " speaker system. Your success with this project will depend on your budget, and the time and effort you dedicate to it. Please keep us informed of you progress.
You may have to some side wall acoustic treatment but that comes after you decide on a speaker system.
You may have to some side wall acoustic treatment but that comes after you decide on a speaker system.
Post #43
Hi astrojet,
Metric is just fine.
Here a few things I noticed: the flare rates should probably be set to Par, as that reflects the expansion w/ two sides parallel to each other, and the other two flared.
http://www.diyaudio.com/forums/subwoofers/256920-par-vs-con-hornresp.html
Now, obviously there may be reasons to use another flare rate, e.g.: if your design expansion rate is exponential over multiple horn sections that you are expressing in Hornresp as a single section because you ran out of sections.
You can check the particle velocity at the mouth by going: Calculate - Tools/Output/Horn - Tools/Particle Velocity/Horn mouth. This one comes in @ 22.60 Hz V=21 m/s for your given Eg. To see what is going on in the S3/S4 section enter 68.50 into S5, and take another look at the horn mouth particle velocity, now @ 21.34 Hz V=33.7 m/s. Try to keep that value below 15 m/s (just a rule of thumb). The flared end of the port should be your main concern, but it doesn't hurt to be conservative here.
hottatoo has a point it would be nice to have a full horn system. Ernst Georg Beck had a 15" Basshorn California that looks like it may have useable output to ~40Hz, don't know anything good or bad about it, that's about the minimum size. A horn that will get you to an honest 30 Hz is going to be big.
Regards,
Hi astrojet,
Metric is just fine.
Here a few things I noticed: the flare rates should probably be set to Par, as that reflects the expansion w/ two sides parallel to each other, and the other two flared.
http://www.diyaudio.com/forums/subwoofers/256920-par-vs-con-hornresp.html
Now, obviously there may be reasons to use another flare rate, e.g.: if your design expansion rate is exponential over multiple horn sections that you are expressing in Hornresp as a single section because you ran out of sections.
You can check the particle velocity at the mouth by going: Calculate - Tools/Output/Horn - Tools/Particle Velocity/Horn mouth. This one comes in @ 22.60 Hz V=21 m/s for your given Eg. To see what is going on in the S3/S4 section enter 68.50 into S5, and take another look at the horn mouth particle velocity, now @ 21.34 Hz V=33.7 m/s. Try to keep that value below 15 m/s (just a rule of thumb). The flared end of the port should be your main concern, but it doesn't hurt to be conservative here.
hottatoo has a point it would be nice to have a full horn system. Ernst Georg Beck had a 15" Basshorn California that looks like it may have useable output to ~40Hz, don't know anything good or bad about it, that's about the minimum size. A horn that will get you to an honest 30 Hz is going to be big.
Regards,
Attachments
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tb46:
I will give you a quote from Dr. Bruce " Avoid any folds in a mid bass horn--it compromises the quality of the midrange. " I tried 2 folded mid bass horn designs, one using a 12" woofer and one with a 15" woofer which has very similar construction/size to the California horn you posted and it sounded very good to about 150-200hz but that all important midrange sounded colored and less defined. However it was quite useable. Compared to a front loaded horn it was no contest--much more clarity, much better imaging and presence plus 105+ efficiency for one watt !!!! A winner in my book.
The construction of the mid bass horn I found to be easier than the other 2 folded horns and the end result sounded just great.
I will give you a quote from Dr. Bruce " Avoid any folds in a mid bass horn--it compromises the quality of the midrange. " I tried 2 folded mid bass horn designs, one using a 12" woofer and one with a 15" woofer which has very similar construction/size to the California horn you posted and it sounded very good to about 150-200hz but that all important midrange sounded colored and less defined. However it was quite useable. Compared to a front loaded horn it was no contest--much more clarity, much better imaging and presence plus 105+ efficiency for one watt !!!! A winner in my book.
The construction of the mid bass horn I found to be easier than the other 2 folded horns and the end result sounded just great.
Hi astrojet,
As I haven't been able to find a "midbass horn" that comes even close to your design parameters (and it's not for lack of trying), I'll attach one more stab at the offset driver tapered transmission line w/ two aspect ratios. The Hornresp Export file is also attached, just import it into Hornresp.
Regards,
As I haven't been able to find a "midbass horn" that comes even close to your design parameters (and it's not for lack of trying), I'll attach one more stab at the offset driver tapered transmission line w/ two aspect ratios. The Hornresp Export file is also attached, just import it into Hornresp.
Regards,
Thanks Oliver. The outer dimensions of the bottom design are just about a perfect fit (aesthetically) for the room. Qualitatively, what do you think about the frequency response?
The input file is great. I'll fool around with Hornresp tonight to see if I could shift the driver a little farther down, as it might mean I can set the tractrix horns on top of the bass cabinets. I've found a local supplier that can get me a pair of Lab 12 delivered for right at $500 USD.
The input file is great. I'll fool around with Hornresp tonight to see if I could shift the driver a little farther down, as it might mean I can set the tractrix horns on top of the bass cabinets. I've found a local supplier that can get me a pair of Lab 12 delivered for right at $500 USD.
One of my previous question is unanswered (or I can't find it by quick browsing) - is the rear of mid-horn sealed (chambered), or open?
Back then when I used Oris 150 horn, I like the sound with the rear open. Although the rear radiation is much less SPL than the front, it's still splashing rearward (and then everywhere). So the dipole bass is matching pretty well. (And that's why I recommended OB)
If your mid horn is also rear open, than the overall dispersion should be taken into consideration, especially the room layout is very uncommon.
Also, this thread would be a good read: http://www.diyaudio.com/forums/subwoofers/227233-vented-vs-th-sound-quality.html
Back then when I used Oris 150 horn, I like the sound with the rear open. Although the rear radiation is much less SPL than the front, it's still splashing rearward (and then everywhere). So the dipole bass is matching pretty well. (And that's why I recommended OB)
If your mid horn is also rear open, than the overall dispersion should be taken into consideration, especially the room layout is very uncommon.
Also, this thread would be a good read: http://www.diyaudio.com/forums/subwoofers/227233-vented-vs-th-sound-quality.html
Hi CLS.
Very sorry I neglected to answer! Yes, I have a back chamber. Pic is attached. I added some panels on the inside to reduce the volume, as it seemed to sound better when I did.
Why do you no longer use horns?
Hmm, I'll take the back off and run them for a bit, but this would create a wave-guide for most of the relevant frequencies, as the loading chamber is relatively deep.
Thanks for the link. I'll be sure to read it.
As an aside, I just got back from a few weeks working in your beautiful homeland of Taiwan. Visited the great James trafo shop while I was there too. I didn't manage to find any Tangband drivers though....
All the best.
Very sorry I neglected to answer! Yes, I have a back chamber. Pic is attached. I added some panels on the inside to reduce the volume, as it seemed to sound better when I did.
Why do you no longer use horns?
Hmm, I'll take the back off and run them for a bit, but this would create a wave-guide for most of the relevant frequencies, as the loading chamber is relatively deep.
Thanks for the link. I'll be sure to read it.
As an aside, I just got back from a few weeks working in your beautiful homeland of Taiwan. Visited the great James trafo shop while I was there too. I didn't manage to find any Tangband drivers though....
All the best.
Attachments
Thanks for the kind words to Taiwan, it's a good place for itself, but overly crowded now. (James, as I know, is a person who is very serious and enthusiastic on what he does. I met him once or twice. TB's products are not in the local market here. The company is doing purely exporting. Many companies here are like that.)
I (temporarily) put the big horn aside is because it's difficult for me to do various experiments with it. Oris horn itself is a good stuff, but building a whole system properly around it is not easy, let alone extending its strength towards both ends and exploring furthur possibilities...
Well, you know this, don't you?
I (temporarily) put the big horn aside is because it's difficult for me to do various experiments with it. Oris horn itself is a good stuff, but building a whole system properly around it is not easy, let alone extending its strength towards both ends and exploring furthur possibilities...
Well, you know this, don't you?
No need to thank me for the kind words about Taiwan -- as it is a stunning place. Everyone out there in internet land that wants to see big mountains with dense foliage rising from the Pacific or eat some choice home cooking should venture to your island!
Yes, James is a king of a guy. That was my second visit to pick up some iron from him. He is working on some new output transformers with selectable primary impedance. Cool.
It may be difficult to integrate the mid-horns into a system, but honestly, with the clarity and depth of the mid-range, I can't imagine not putting in whatever effort it takes.
Yes, James is a king of a guy. That was my second visit to pick up some iron from him. He is working on some new output transformers with selectable primary impedance. Cool.
It may be difficult to integrate the mid-horns into a system, but honestly, with the clarity and depth of the mid-range, I can't imagine not putting in whatever effort it takes.
PPSL
Hi astrojet,
Just real quickly a word on the PPSL.
Post #24: "...Has anybody every done this successfully with 10"s or even 8"s?"
I put the attached Dual 10" PPSL together very quickly, didn't check any volumes, just a very quick stab at it. It would most likely need tunig via the duct length. The front opening can be reduced from the combined Sd by about 50 or 60 % (~ 0.4 x Sd minimum). The plenum should be kept as small as possible, which in case of this particular car subwoofer means that you have to make the rear panel removable for access. For an actual build the driver size and cone depth, etc. need to be checked.
I think these drivers are available in New Zealand, usually they sell somewhere at a discount. They should be fine for the desired frequency range.
Maybe, take a look at this in Hornresp.
Gotta run.
Regards,
Hi astrojet,
Just real quickly a word on the PPSL.
Post #24: "...Has anybody every done this successfully with 10"s or even 8"s?"
I put the attached Dual 10" PPSL together very quickly, didn't check any volumes, just a very quick stab at it. It would most likely need tunig via the duct length. The front opening can be reduced from the combined Sd by about 50 or 60 % (~ 0.4 x Sd minimum). The plenum should be kept as small as possible, which in case of this particular car subwoofer means that you have to make the rear panel removable for access. For an actual build the driver size and cone depth, etc. need to be checked.
I think these drivers are available in New Zealand, usually they sell somewhere at a discount. They should be fine for the desired frequency range.
Maybe, take a look at this in Hornresp.
Gotta run.
Regards,
Thanks Oliver.
After a lot of reading, I think I've at least settled on a forward facing design, mainly hoping for the flexibility of running it at woofer frequencies if the horns prove to be too non-linear down at their lowest frequencies.
I very much like the OD MLTL of the previous posts. After the honeymoon period with Hornresp wore off (the one in which every novice feels overly optimistic!), it seems not so easy to adjust random lengths, etc. without causing cascading and detrimental effects. I'm thinking about just biting the bullet, buying some drivers, and getting them running in a sealed enclosure while I try and finalize changes to the TL design until I'm happy with it. It will take me a fair amount of faffing before it is fully constructed.
With that plan, anyone care to peruse the attached spreadsheet listing 4 pro-driver options that are readily available to me and let me know if you think any are suitable? I understand what is perfect for a sealed won't be perfect for a TL, but I'm just looking for something that will be passable in the sealed to buy me some time to construct something better. I'm not super worried about the low xmax, as I never listen loud enough to shake the neighbours.
All the best.
After a lot of reading, I think I've at least settled on a forward facing design, mainly hoping for the flexibility of running it at woofer frequencies if the horns prove to be too non-linear down at their lowest frequencies.
I very much like the OD MLTL of the previous posts. After the honeymoon period with Hornresp wore off (the one in which every novice feels overly optimistic!), it seems not so easy to adjust random lengths, etc. without causing cascading and detrimental effects. I'm thinking about just biting the bullet, buying some drivers, and getting them running in a sealed enclosure while I try and finalize changes to the TL design until I'm happy with it. It will take me a fair amount of faffing before it is fully constructed.
With that plan, anyone care to peruse the attached spreadsheet listing 4 pro-driver options that are readily available to me and let me know if you think any are suitable? I understand what is perfect for a sealed won't be perfect for a TL, but I'm just looking for something that will be passable in the sealed to buy me some time to construct something better. I'm not super worried about the low xmax, as I never listen loud enough to shake the neighbours.
All the best.
At the risk of seeming spazzy, or at least wishy-washy, that early suggestions of a Karlson might be great for the 12g125, with low Q and high Bl....
and about as quick a build as a sealed for a test or the interim. Specs are: 12", Fs=41 Hz, Vas = 122 litre, sens = high 90s, Qms=2.0, Qes=0.31, Qts=0.27, BL = 15.8 N/A.
I have no idea how to practically interpret the Qms value.
Thoughts very much appreciated.
and about as quick a build as a sealed for a test or the interim. Specs are: 12", Fs=41 Hz, Vas = 122 litre, sens = high 90s, Qms=2.0, Qes=0.31, Qts=0.27, BL = 15.8 N/A.
I have no idea how to practically interpret the Qms value.
Thoughts very much appreciated.
Hi astrojet,
I'm not familiar w/ those Beyma's. They would not work well in an enclosure designed for speakers w/ a much heavier Mmd... They also would not work well in a sealed enclosure. I don't know if you have access to a Beyma 12BR70, it would work well in a 105 L vented box w/ dual 3"I.D. ducts tuned as you like it, e.g.: for a slightly sloping response use 10" duct length, half of that for ~flat.
For Karlsons contact xrk971, he can give you an idea as to which size would be applicable, and if a Karlsonator might be better; xrk971 is the only person I know at these forums, that has a working AkAbak model for the Karlson enclosures. freddi and Greg V are the general goto guys for anything Karlson.
http://www.diyaudio.com/forums/full-range/213594-karlson.html
http://www.diyaudio.com/forums/full-range/239386-karlsonator.html
Best of luck, Regards,
I'm not familiar w/ those Beyma's. They would not work well in an enclosure designed for speakers w/ a much heavier Mmd... They also would not work well in a sealed enclosure. I don't know if you have access to a Beyma 12BR70, it would work well in a 105 L vented box w/ dual 3"I.D. ducts tuned as you like it, e.g.: for a slightly sloping response use 10" duct length, half of that for ~flat.
For Karlsons contact xrk971, he can give you an idea as to which size would be applicable, and if a Karlsonator might be better; xrk971 is the only person I know at these forums, that has a working AkAbak model for the Karlson enclosures. freddi and Greg V are the general goto guys for anything Karlson.
http://www.diyaudio.com/forums/full-range/213594-karlson.html
http://www.diyaudio.com/forums/full-range/239386-karlsonator.html
Best of luck, Regards,
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