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Post by gohantanch on Oct 17, 2013 18:00:22 GMT -5
I have been mulling over the idea of building a pair of open baffle speakers. I got the idea from a customer of mine that does it on a grand scale(we're talking $50,000 drivers. Ridiculous!) and I figure I could make a first shot at a pair in the $200-$300 range.
Anyone out there have any experience with them? I am going in pretty blind. I've never done anything like this but I thing it could be fun.
any tips and/or advice would be greatly appreciated.
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Post by PGT on Oct 17, 2013 21:07:06 GMT -5
open baffle? do you mean infinite baffle?
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Post by gohantanch on Oct 17, 2013 21:29:03 GMT -5
Tomāto, tomato. No enclosure, speakers arranged on a single heavy duty plywood board.
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Post by gohantanch on Oct 17, 2013 21:32:59 GMT -5
 A little example. |
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Post by Boomzilla on Oct 17, 2013 21:38:56 GMT -5
There is a long and successful tradition of such speakers. Jon Dahlquist's famous DQ-10 (a GREAT speaker, by the way) used open baffle. The Vandersteen line uses much of the same philosophy.
Buy good drivers, use a good crossover, and let it rip! Any more, most such speakers that I see fillet the mounting board to provide even less surface area for the baffle. The most extreme ones use just a skeleton of metal to hang the drivers in mid air. From what I have read, they all sound very good.
Post photos! Boomzilla
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Post by gohantanch on Oct 17, 2013 21:57:41 GMT -5
There is a long and successful tradition of such speakers. Jon Dahlquist's famous DQ-10 (a GREAT speaker, by the way) used open baffle. The Vandersteen line uses much of the same philosophy. Buy good drivers, use a good crossover, and let it rip! Any more, most such speakers that I see fillet the mounting board to provide even less surface area for the baffle. The most extreme ones use just a skeleton of metal to hang the drivers in mid air. From what I have read, they all sound very good. Post photos! Boomzilla Current financial limitations are gonna make it a semi-long term project and it being my first try I will be doing this with more budget parts this time. Here is a sketch I did of my idea at least (yes it looks like a 5th grader did it)...  |
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Post by Boomzilla on Oct 17, 2013 22:02:36 GMT -5
Looks like a plan!
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Post by gohantanch on Oct 17, 2013 22:05:22 GMT -5
The seed of an idea anyways. I've never soldered anything before so I get to experience a lot of firsts. |
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Post by PGT on Oct 17, 2013 22:10:43 GMT -5
Most of the designs I've seen use basically a normal enclosure, minus the rear panel. As long as you're separating the front wave from the back wave, it generally work well. Lots of pro sound speakers are IB for example.
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Post by gohantanch on Oct 17, 2013 22:38:58 GMT -5
There is a long and successful tradition of such speakers. Jon Dahlquist's famous DQ-10 (a GREAT speaker, by the way) used open baffle. The Vandersteen line uses much of the same philosophy. Buy good drivers, use a good crossover, and let it rip! Any more, most such speakers that I see fillet the mounting board to provide even less surface area for the baffle. The most extreme ones use just a skeleton of metal to hang the drivers in mid air. From what I have read, they all sound very good. Post photos! Boomzilla Any idea if I need to try and match driver sensitivities, impedance, and power handling as much as possible? |
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DYohn
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Post by DYohn on Oct 17, 2013 23:08:32 GMT -5
I've designed several OB systems - in fact my HT is all OB right now. What would you like to know? (by the way OB and IB are almost exactly opposite of one another.)
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Post by gohantanch on Oct 17, 2013 23:14:35 GMT -5
I've designed several OB systems - in fact my HT is all OB right now. What would you like to know? (by the way OB and IB are almost exactly opposite of one another.) Any idea if I need to try and match driver sensitivities, impedance, and power handling as much as possible? Earlier in the thread I posted a rough sketch(emphasis on the rough) of my idea for me first try, what do you think? |
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DYohn
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Post by DYohn on Oct 17, 2013 23:30:21 GMT -5
Not a bad looking plan, although I have these comments:
1) I have never seen an AMT tweeter that cheap at retail. What model is it? Is it dipole or monopole?
2) You list prices for all the drivers so you must have them picked out. What are they? Not all drivers are suitable for OB alignment (for example, you really need to choose drivers with Qts > 0.5)
3) Did you design the width of the upper and lower baffles for a specific f3 and if so, how does that fit with the crossover points and the driver's fs?
4) Again as to your pricing. I assume you are trying to use an off-the-shelf 3-way crossover if you are buying it for that price. This is really not the best approach, especially for an OB system.
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DYohn
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Post by DYohn on Oct 17, 2013 23:40:13 GMT -5
For reference here's a shot of my current 4-way OB system that function as my HT mains (actually this is an early prototype version. The bass bin is modified from this setup as I didn't like the output.)  Here's a shot of one of the crossovers. Trust me the components here cost a lot more than your total system estimate, which is one reason why I'm asking my questions.   |
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Post by mauriceminor on Oct 17, 2013 23:46:25 GMT -5
Worthwhile information at: www.linkwitzlab.com and www.commonsenseaudio.comFull range speakers make life easy, perfect for a first attempt Baffle design is critical, take a look at Linkwitz's LX521 top baffle design Siegfried Linkwitz provides excellent information on the advantages of the OB design When the speakers are properly placed room acoustic issues are minimal |
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Post by gohantanch on Oct 17, 2013 23:50:53 GMT -5
Not a bad looking plan, although I have these comments: 1) I have never seen an AMT tweeter that cheap at retail. What model is it? Is it dipole or monopole? 2) You list prices for all the drivers so you must have them picked out. What are they? Not all drivers are suitable for OB alignment (for example, you really need to choose drivers with Qts > 0.5) 3) Did you design the width of the upper and lower baffles for a specific f3 and if so, how does that fit with the crossover points and the driver's fs? 4) Again as to your pricing. I assume you are trying to use an off-the-shelf 3-way crossover if you are buying it for that price. This is really not the best approach, especially for an OB system. Honestly I have no clue about half the questions you had but if you would bare with me I will try and answer them. This is my very first time attempting anything like this. 1. Here is the info on the tweeter. Product Description The Dayton Audio AMT Mini-8 model features a round housing and compact AMT element, for wide dispersion that easily replaces dome tweeters in retrofit or new design applications. The AMT Mini-8 is small enough to be used in compact satellite speakers, or installed in the center of a mid-woofer to create a full-bandwidth coaxial driver, or implemented in other ways -- including line arrays. The sealed rear chamber design of the AMT Mini-8 eliminates the need for a separate internal chamber in the loudspeaker enclosure. Dayton Audio AMT (Air Motion Transformer) tweeters use groundbreaking transducer technology from the original ESS/Heil Air Motion Transformer to provide ultra-clean, detailed, and dynamic treble output. The pleated ribbon diaphragm of an AMT provides a large acoustic radiating area condensed into a compact chassis, for extremely high output and improved power handling. Specifications: Dimensions: Overall diameter: 1.59", Depth: 0.91". Note: This tweeter is designed for press-fit mounting. PRODUCT DETAIL Model Number AMT Mini-8 List Price $35.99 Color Black Unit of Measure Each UPC 848791000652 Product Shipping Weight (lbs.) 0.1300 PRODUCT SPECIFICATIONS Speaker Type Tweeter Power Handling (RMS) 15 watts Power Handling (max) 30 watts Impedance 8 ohms Sensitivity 88 dB @ 1W/1m Frequency Response 3,500 - 40,000 Hz THIELE-SMALL PARAMETERS DC Resistance (Re) 7.19 ohms Resonant Frequency (Fs) 3,500 Hz Total Q (Qts) 2.8 Surface Area Of Cone (Sd) 3.8 cm2 Dual Voice Coil No Shielded No 2. The Qs on the midrange woofer is .9 and the Qs on the 15" woofer is 1.39 3. Frankly I designed it like that because I thought it looked good  Not sure what you mean by F3. 4. I chose the crossover partly because it's cheap I didn't want to put too much into an experiment, and because the frequencies for the bass, midrange, and highs are pretty much where I wanted them. so what are your thoughts and/or suggestions? |
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Post by mauriceminor on Oct 18, 2013 0:23:08 GMT -5
I have been mulling over the idea of building a pair of open baffle speakers. I got the idea from a customer of mine that does it on a grand scale(we're talking $50,000 drivers. Ridiculous!) and I figure I could make a first shot at a pair in the $200-$300 range. Anyone out there have any experience with them? I am going in pretty blind. I've never done anything like this but I thing it could be fun. any tips and/or advice would be greatly appreciated. Visit www.diyaudioprojects.com and enter 'open baffle' in the search box Several successful designs to study Best of all, $150 gets it done |
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Post by luvtubes on Oct 18, 2013 1:02:10 GMT -5
You could always look for a pair of Carver Amazing Loudspeakers and start there. They can be found for not much more than you will spend on a DIY build. Just upgrade the crossovers and add music.
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selkec
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Post by selkec on Oct 18, 2013 6:02:47 GMT -5
For reference here's a shot of my current 4-way OB system that function as my HT mains (actually this is an early prototype version. The bass bin is modified from this setup as I didn't like the output.) Here's a shot of one of the crossovers. Trust me the components here cost a lot more than your total system estimate, which is one reason why I'm asking my questions. Sweet looking sppeakers. Can you build me a set? maybe close in the bass bin a little  |
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DYohn
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Post by DYohn on Oct 18, 2013 9:29:07 GMT -5
so what are your thoughts and/or suggestions? I have several thoughts, but first a few more questions. 1) What is the make/model of the mid-woofer you want to use? 2) What is the make/model of the crossover? 3) What are the widths in inches of the two sections of your baffle design? Once I know this I will be able to make a few suggestions. But I can already tell you the first one is likely to be that the mid-woof you have chosen is not the best choice. I was not aware of the Dayton folded ribbon, I will check that out. Since this is an experiment I understand wanting to keep it inexpensive. So why try such a complex design? There are many ways to experiment with OB that do not involve building a 3-way MTM system. -edit- I just looked up that Dayton Mini-8 AMT tweeter and it really is not suitable for any use other than as a super tweeter. I would not recommend using it below 7KHz and the output is not listed as anything close to flat until 9KHz. You really need a ribbon with a larger diaphragm to use as a standard tweeter. If you want to stick with an AMT (and I don't blame you they usually sound great) a much better low-cost choice would be the Dayton AMT-2. |
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Not sure what you mean by F3.
