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Everything posted by mwmkravchenko

  1. Yep. And you have some great SPL numbers there. A true horn for two of those drivers would be enormous. It would have to be built into a theater rider like I've designed for a few clients. But get you even greater output. Impressive bit of work. I appreciate your level of detail in the files.
  2. Interesting. Master Ricci, has anyone pointed out that this is a bandpass box. Not a horn? I like the output capabilities. But this is not a horn. You have two drivers in two separate chambers couples on both sides of the drivers to vents. Nice classic bandpass enclosure. Awesome bit of design work at any rate.
  3. Those curves look vaguely familiar... Great results for all your hard work Brian.
  4. I completely forgot about this spreadsheet. Thorborg advanced inductance spreadsheet If I remember half of what I have forgotten, I'd be more dangerous
  5. There are a few more papers other than the Thorborg paper that Bolserst used. If anyone wants the papers let me know and I'll be happy to forward them to you.
  6. The complex inductance capability is finally incorporated in to Hornresp. Nice to see. Much of the effort belongs to bolserst and David McBean. It's a situation of providing the correct frame work and the proper papers behind that framework. Hornresp is getting pretty interesting these past few months. Moving closer to LEAP kind of computational simulation capabilities.
  7. Kyle I like the new format that you have proposed. Nice. Only one thing I am wondering. Are you limited to a certain window height for the graphs? Or are you trying to keep the same vertical perspective on the distortion plots. The Klipsch sub should have Mr. K turning in his grave!
  8. Agreed. I'm very much not a fan of one curve fits all and auto generated room EQ. All you have to do is move about the room a little bit and your wonderful EQ is out the window.. We are basically agreeing on the room timing measurements. My unstated reasoning is that an accurate measurement cannot be made without a stimulus that actually excites all the room modes. In most cases this precludes the MLS types of signals. You need chirps and or discrete gated sine wave stimulus to really excite what can happen below around 200 hertz. DFT gating is also very important to be chosen correctly as you have pointed out. And the correct type of math Math on the DFT. Choose wisely or suffer the consequences
  9. I'm guessing that this Audyssey EQ is a sliding dynamic loudness contour. That does have application when you are listening at levels below 70 to 75db averaged. Simple comment on room measurements. They are very dependent on the stimulus made to take the measurement and the type of math applied to perform the measurement. The errors multiply rather rapidly depending on the choices made. I know of no professional who works in acoustics that looks at averaged measurements and gives them any worth. Raw measurements are where the real information lies. Lastly. I may have not posted the links to all the Sean Olive Papers and may be remembering What I was reading in the JAES papers freely available and also on the JAES website. But I know for a fact that the reference speakers were in a standardized listening room and that the panel of trained listeners preferred the sound characteristics associated with a standardized semi-reverberant room. Not an anechoic reproduction also called diffuse field EQ that was the norm for a few years back.
  10. The writers of those articles would have a very healthy argument that you are incorrect. And so would I I often use a high quality pair of headphones as a reference when working on loudspeakers. The entire basis of the articles I cited are the relationships between the sound of an accurate pair of speakers and an accurate pair of headphones. Don't allow what you have in a headphone sway your decision. There are some headphones that have been designed with this type of carefully crafted contour. The data for this type of EQ matching loudspeakers is widely available in many reports and there is even standards that are in the works to define an accurate headphone response. They all use a well setup loudspeaker as a reference.
  11. http://seanolive.blogspot.ca/2014/01/the-perception-and-measurement-of.html http://read.uberflip.com/i/324330-lis-2014/22 http://seanolive.blogspot.ca/2008/12/loudspeaker-preferences-of-trained.html A lot larger pool of people than I have ever had the chance to work with agree that listener preferences are universally agreed upon regardless of age. Good sound is simply put, the right sound. Right in the sense that it accurately reproduces the sound of a live acoustic event. Caveat being that when you set up a loudspeaker system in this way many recordings are exposed for a series of poor choices. And poorer outcome in reproduced sound. One last note. There should be no difference between accurate reproduction on a loudspeaker and accurate reproduction on a headphone. That is the anchor of this series of research articles. After all you are using the same set of ears for both types of listening aren't you?
  12. Some how I don't quite agree with that summation. True some people like little or no treble. But that is not really attributable to age. I have clients and colleagues that are long in the tooth but really appreciate an extended top end response. I do agree that your idea of a generally accepted loudspeaker response is best described as subjectively flat. Most systems that I have listened to that were dead flat were very bright on the top end. My personal work aims for a combined listening position that is down a few db beyond 10 khertz. Down about 1.5 to 2 db in the last octave.
  13. Welcome to my world has been ringing in my head after reading your post Brian. You are ironing out many of the problems, and discovering new ones. It is what engineering actually consists of.
  14. Happy to hear you have attained your goals. Now the real fun begins. Listening to music!
  15. Nice work! Ground plane. Get friendly with some pieces of plywood and duct tape. Place them on the pavement and tape the joints. Two sheets will allow you a 2 meter measurement distance all around your box.
  16. I have done a fair bit of design work for directional control of tweeters. I also have done horn design since 1994. So I nit pick when I hear waveguide and horn. There is so little difference that I have come up with this as a qualifying factor for one versus the other. If there is an efficiency gain in the output of the driver in the new mounting then it is a horn. If there is no gain in efficiency then it is a waveguide. The trick in that definition is that there is always some change in the efficiency of the driver when mounted in a constraining coupling area from smaller to larger. So waveguide is basically a marketing name that tried to distance the concept from terrible sounding horns. And for sure you will get me to agree that there are a lot of terrible sounding horns. There are also some really great sounding horns. If I remember correctly Genelec has one of the few smaller format monitors that claims to have a very controlled dispersion pattern. I have seen the enclosure but not worked through it's design in any detail. But it uses a combination of time delay that is naturally occurring through the cabinet design and the driver mounting coupled with some DSP correction. DSP is not magic. If your speakers sounds crappy to begin with you will only make it marginal with the most brute force correctional you can buy. That I have witnessed from one of the top DSP designers in the world. It is impressive to hear many of the warts fade. But they are still there. DSP cannot correct for poor driver design. And if there are serious resonance distortions in the drivers cone surround or spider. Those types of flawes in design will dominate the sound no matter what you do.
  17. Tweeters, midwoofers a 24 inch high efficiency woofer and a cold beer. Beeeeeer!

  18. You can only get constant directivity using a few methods. And the directivity control is frequency dependent. So each few octaves of response need another of controlling the directivity. Correctly designed horns is the only broad band method that really works. But that is a difficult task. A good horn only covers a few octaves of frequency response before it looses it's effective directivity. And as you go lower in frequency the horns must get larger. Can be done. And I have done design work for it. But it is not a small system. Think 4 horns where the largest is almost 5 feet square to control directivity down to about 64 hertz. A simple suggestion. Finish what you are working on. It will be great.
  19. A kilowatt is no big deal in terms of power availability. Enclosure size is cast in stone it looks like. You are indeed doing a nice job on your enclosure. The driver has all the quality of the Scandinavian drivers. With a cost that is about $18 over landed cost. The only improvements I could make is a smaller stronger motor and a larger coil. Add to that a custom surround and spider and you have tapped out the possible improvements.That is in fact what I have done on my 7 inch. A little more X-max and a little more refinement on the cone surround interface. But I'll tell you that blindfolded in front of two of them I doubt that I could tell them apart. Under controlled conditions with a set of each in a two way speaker configuration my guess would be I probably could tell them apart. Basically because I paid a little more attention to the cone. And I have a larger cone. An attempt at getting the most from the least. I know that Stereo Integrity makes a very high quality shallow 6.5. And it has comparable build quality. I started out making speakers using the best of the Scandinavian stuff. http://www.kravchenko-audio.com/blog Old pictures taken with a box camera. ( remember those?)
  20. Have you considered this driver: http://www.diysoundgroup.com/anarchy-woofer.html I design and produce drivers for a living. And I have used this driver. It is extremely well engineered and is of equal or better build quality to what you have chosen. I have no relationship with this driver or the link to the website. It simply is a very well made driver. And it sounds great.
  21. Probably the best selling point on a high efficiency driver is the correlation between where they are efficient and where the bulk of what is considered "bass" is centered. 60 hertz is where the money is. And many pro drivers will get you higher spl for a given size versus a conventional subwoofer with much less power input. Last point. Amp power never makes up for the nearly 10 dB of greater efficiency. Do the math and ask a very simple power compression question. You will find the answer!
  22. Some of the best work done in this field is by people wanting to simulate musical instruments. And this video is of a mitered organ pipe. Or a rectangular organ pipe that has a 90 degree bend. Sometimes they even have a 180 degree bend. I have a boat load of thesis papers and other studies that get to the number crunching but it's nice to see something rather than read about it.
  23. So guessing you are redoing the data-bass website? I know your pain. In the midst of a large redo on mine to. And I cheat with Weebly. NOo real coding just have to come up with a lot of content.
  24. Hello Kyle. I have heard about you from Josh but never had the pleasure of talking with you. I guess this is a close second. I think quite a few people have written their PHD on that subject! Just a speaker Don't get me started on that one. The truth of the matter is at very few times are we going to tax the port compression on a properly designed subwoofer. And the times when that does happen we usually have program material that masks the effect in the first place. And the difference between no problems from a port at any time is the difference between a realistic enclosure size and a not so realistic enclosure size. Twin 18 with an 18 inch diameter port. Wow. A genuine phallic idol to the vent gods if there ever was one!
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