Phil, the idea that a driver has to be low qt and hi Bl is not as accurate as once believed. There is no real major disadvantage to putting a higher qt driver in a TL BLH as long as you work within the specs. The reason I have been able to completely kill step loss is a combination of this driver's qt, Xmax and making sure I roll the horn off and the TL on at ideal times. I just designed the line to account for that. It's all in the math to begin with then finessing through sims then building and rebuilding. I can tell you if you heard this speaker you wouldn't wonder at all if it's a good idea. Now, technically, a full scale horn that reaches to the depths doesn't work ideally with a high Qts driver and would create a fairly boomy system but when one scales the horn down and takes in to account that what we are designing isn't actually a horn below a fairly high mid frequency and is in reality a TL then you find that almost any driver can be placed in a hybrid enclosure such as this if you take in to account these factors.
Tom
Tom
But there's always room to improve!
Okay, so here is the newer worksheets with an in room sim set up almost exactly where I have it and with a one meter on axis analysis. It's amazing how close it is to what I am dealing with. Maybe I will believe the sim a bit more now. Tom
I will put up the enclosure geometry tomorrow as I just got home from a friends mothers funeral so I'm wiped.
Things got very busy over the holiday so I wasn't able to get the mathcad entries up. I did order a new calibrated mic (dayton imm-6 for my ipad to use with audiotools. Completely awesome I might add) and ran a pink noise average. The results are not surprisingly quite similar to my behringer with a preamp. The only differences seem to be not having to lug a huge test setup around. This will make it super easy to do my "anachoic" large field with a platform tests. Only thing I'm missing is an amp that runs on batteries. I will need to buy a t-amp and create a calibration for it and I should be golden!
Tom
Tom
So a little update is in order. I have not moved them from where I set them initially in the two corners on the narrow end of my office (20 feet by 9 feet). I haven't changed the amount of acrylic batting I put in to begin with (1/2 pound per cubic foot). I have been allowing the drivers some break in and I listen to them almost daily. My current impressions are still extremely favorable. I believe that though I combatted the baffle step to some extent in the deism they still have a rising response which is born out in the graphs of in room response and by what Martin King spoke in depth about in his discussion of contemporary BLH designs. They sound excellent on just about any sort of music but the midrange is a hair thin which I believe is a baffle step issue. I am going to build a 3, 6 and 9 db attenuation circuit just to see what the different results show. The next steps will be as follows:
1. Play with the stuffing to see what the effects on FR will be. I don't have any stuff in the line or felt either, just in the CC.
2. Mess with baffle step circuits to try and remove some upper mid thinness though thin isn't exactly what I would call it. They are still very robust.
3. Play with the design and simulations to resolve FR issues.
4. Build the matching left and right TL sub-woofers to fill out the bottom end.
As for my feelings on the project thus far, I believe this has been one of the more successful initial builds I have designed or built. They sound good with just about any sort of music which is odd for a driver of this size and they look rather smart as well. I will say, I hope someone else hops on board for this or at least early in the next iteration. I'd love to hear impression from others.
Tom
1. Play with the stuffing to see what the effects on FR will be. I don't have any stuff in the line or felt either, just in the CC.
2. Mess with baffle step circuits to try and remove some upper mid thinness though thin isn't exactly what I would call it. They are still very robust.
3. Play with the design and simulations to resolve FR issues.
4. Build the matching left and right TL sub-woofers to fill out the bottom end.
As for my feelings on the project thus far, I believe this has been one of the more successful initial builds I have designed or built. They sound good with just about any sort of music which is odd for a driver of this size and they look rather smart as well. I will say, I hope someone else hops on board for this or at least early in the next iteration. I'd love to hear impression from others.
Tom
Hi Tom,
Your mesurement seems to be good..
Maybe a far field mesurement must show other things.
Add a BSC is good idea, maybe you can try a variable BSC :
http://www.quarter-wave.com/General/BSC_Variable.pdf
I test it with good results, add a cap for more spl in hight frequencies.
Phil.
Your mesurement seems to be good..
Maybe a far field mesurement must show other things.
Add a BSC is good idea, maybe you can try a variable BSC :
http://www.quarter-wave.com/General/BSC_Variable.pdf
I test it with good results, add a cap for more spl in hight frequencies.
Phil.
So I've had a pair of the RS100-4's sitting on my workbench since I pulled them out of my Toyota Tundra (used in an active 3-way front stage) and I'd like to put them to use (sold the truck). My wife hasn't been all that amenable to my Tritrix TL mains in the living room. Probably due to their size and the crappy veneer job I did on them. In any case I'd LOVE to emulate this design but want to make sure before the wood hits the blade that it's fully tested and vetted out. I don't need it to be perfect as these are just being built to better the crap TV speakers in my 60" Sharp AQUOS.
I've currently got an Onkyo TX-NR515 to power them. I don't have the need nor provisions to use all 7 channels so stereo use it is, for now. Anyhow, would I be happy with this design as its presented for levels below 85dB's in my open living room that's about 12' x 16' and open to a staircase and the kitchen/dining room?
It's carpeted and I have a low "entertainment" cabinet that they can rest on to lift them off the floor by about 18".
I've currently got an Onkyo TX-NR515 to power them. I don't have the need nor provisions to use all 7 channels so stereo use it is, for now. Anyhow, would I be happy with this design as its presented for levels below 85dB's in my open living room that's about 12' x 16' and open to a staircase and the kitchen/dining room?
It's carpeted and I have a low "entertainment" cabinet that they can rest on to lift them off the floor by about 18".
I feel you would be nothing but happy. I am still astounded by their size and stage. I would never believe that the speakers I am listening to are a diaphragm of such minuscule proportions. I haven't had time to put together much in the way of plans but the cut sheet and layout plan should be enough. I am experimenting now with the stuffing and felt now. They are easily good to 90-95 db or more without breaking up. Classical has authority and bass, jazz is so lifelike and "right". Rock is smooth and very listenable. Even heavy electronica hasn't been a problem for them. Once I have the subs sorted ill post them and a full plan work up for the system. Let me know if you have any questions. The subs will be the same depth as the speaker and 12 inches square x and y so if they work as planned be a very integrated bass unit that the speaker sits on or is directly bolted to.
Tom
Tom
No filters, no crossover. 1.4 ounces of fiber in the CC currently. I don't feel the need for the filter though I may try one soon. the baffle step is very close to dealt with in the current design. The drawings from the first post are the ones I built and I'm not entirely sure there is anything in need of alteration at this point though I would be open to thoughts on that. My tests show a very favorable speaker in my room. I haven't yet had a chance to try them on a one wall situation yet, as my room allows them in the corners though I think they will perform well as the design was originally conceived to function in a single back wall situation. The sub should fill in nicely for either situation as it's separately amped and therefore infinitely adjustable both in crossover point and volume. Maybe I should build the subs tomorrow to see how they perform. They look as though they will work well at least in the simulation.
Tom
Tom
https://drive.google.com/file/d/0B3vrSGT4ereBNVlqRnpIRm56RnM/edit?usp=sharing
Here are the plans to the "Bartok". Yes, I finally named them. Bartok came to mind as I was using a good deal of Bela Bartok's material while testing them. The name is also appropriate since there is a dissonance to the design that I quite like (visually that is). I'd like to think there are no errors in the measurements. I don't make any claims of "correctness" but I do believe it is accurate. I still suggest comparing your numbers when cutting anyway as this is just smart practice when building another person's plans. (Feel free to let me know if there are problems with the plan).
The H-Frame sub-woofer portion is as yet untested but does sim well in the MJK Mathcad worksheets so I can only assume they will work as intended. I am going to try to build them within the next week or two. It's been so cold here that working in the shop or outdoors is miserable therefore I've been trying not to do too much outside.
I hope those present have enjoyed the process of watching me design and test these loudspeakers. Thank you to all who have helped during the process. In particular, Martin J. King (who no longer haunts these halls but spoke with me a good deal about my design and it's pluses and minuses and to whom I owe gratitude for insisting the H-Frame would be an excellent choice for sub-woofer design in this configuration). I hope next time to involve more people in the process. I am happy to share my knowledge and in return show humility to those that have something to offer which is why I had hoped more people would have shown interest and become involved. I'd like to see this community return to the all included group that it seemed to be ten years ago when I became involved. I was a hair disappointed that people were willing to get involved only once they thought it would work. The whole idea of a group project is for those involved to take part, from the beginning, sharing the errors and successes. It is not the point of a group build to wait until someone has designed it and tested it just so you can take from their successes. I believe in fact to reference the past, I was the first to build the Fonken's on this board and the first to build the Frugal Horn outside of Dave's inner circle. I thoroughly enjoyed the act of building an untested plan. Maybe a group build will be possible on a future project as I mentioned previously. The holding of ones knowledge doesn't make one valuable. It tends to make them expendable at the first opportunity.
Once again, thanks to all who helped in the locals pool (you know who you are). I think if anyone builds this speaker they will find it is quite astounding. I am listening to Bill Evans Live at the Village Vanguard as I type and frankly I feel like i am sitting at the other end of a jazz club while the band plays behind me as I am at my desk which is at the other end of my office from the listening setup.
As always, go ahead and share the plans but I retain intellectual property rights to the design and plan under the creative commons license and ask that any use or distribution be accompanied by reference to the author (myself, Thomas Petzwinkler) and the original title (Bartok) regardless of modification to design parameters or aesthetics.
I will continue to post my findings regarding testing and building and encourage anyone interested to take part in the discussion.
Enjoy!
Tom
Here are the plans to the "Bartok". Yes, I finally named them. Bartok came to mind as I was using a good deal of Bela Bartok's material while testing them. The name is also appropriate since there is a dissonance to the design that I quite like (visually that is). I'd like to think there are no errors in the measurements. I don't make any claims of "correctness" but I do believe it is accurate. I still suggest comparing your numbers when cutting anyway as this is just smart practice when building another person's plans. (Feel free to let me know if there are problems with the plan).
The H-Frame sub-woofer portion is as yet untested but does sim well in the MJK Mathcad worksheets so I can only assume they will work as intended. I am going to try to build them within the next week or two. It's been so cold here that working in the shop or outdoors is miserable therefore I've been trying not to do too much outside.
I hope those present have enjoyed the process of watching me design and test these loudspeakers. Thank you to all who have helped during the process. In particular, Martin J. King (who no longer haunts these halls but spoke with me a good deal about my design and it's pluses and minuses and to whom I owe gratitude for insisting the H-Frame would be an excellent choice for sub-woofer design in this configuration). I hope next time to involve more people in the process. I am happy to share my knowledge and in return show humility to those that have something to offer which is why I had hoped more people would have shown interest and become involved. I'd like to see this community return to the all included group that it seemed to be ten years ago when I became involved. I was a hair disappointed that people were willing to get involved only once they thought it would work. The whole idea of a group project is for those involved to take part, from the beginning, sharing the errors and successes. It is not the point of a group build to wait until someone has designed it and tested it just so you can take from their successes. I believe in fact to reference the past, I was the first to build the Fonken's on this board and the first to build the Frugal Horn outside of Dave's inner circle. I thoroughly enjoyed the act of building an untested plan. Maybe a group build will be possible on a future project as I mentioned previously. The holding of ones knowledge doesn't make one valuable. It tends to make them expendable at the first opportunity.
Once again, thanks to all who helped in the locals pool (you know who you are). I think if anyone builds this speaker they will find it is quite astounding. I am listening to Bill Evans Live at the Village Vanguard as I type and frankly I feel like i am sitting at the other end of a jazz club while the band plays behind me as I am at my desk which is at the other end of my office from the listening setup.
As always, go ahead and share the plans but I retain intellectual property rights to the design and plan under the creative commons license and ask that any use or distribution be accompanied by reference to the author (myself, Thomas Petzwinkler) and the original title (Bartok) regardless of modification to design parameters or aesthetics.
I will continue to post my findings regarding testing and building and encourage anyone interested to take part in the discussion.
Enjoy!
Tom
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