OK, so forget the question about why the unmodified sounded so much louder - I looked back at the response graphs and saw why - the huge spike around 6k hz. (Duh, study the data)
I'm still wondering about the vertical vs. horizontal thing, what differace am I supposed to hear?
Mark, looking forward to your next update. I know you have that pesky "making a living" thing to take care of though.
Thanks again for all your help.
MB
I'm still wondering about the vertical vs. horizontal thing, what differace am I supposed to hear?
Mark, looking forward to your next update. I know you have that pesky "making a living" thing to take care of though.
Thanks again for all your help.
MB
Mainly just trying to keep the thread alive here.
Too bad PE is out, but on the other hand, that must mean that a lot of people bought these, so there should be some interest out there.
I'm trying to decide on a tweeter, something in the same price range, just to add a little topend. Any sugestions out there? What about XOs?
Hopefully Mark will have time to give us that update soon.
MB
Too bad PE is out, but on the other hand, that must mean that a lot of people bought these, so there should be some interest out there.
I'm trying to decide on a tweeter, something in the same price range, just to add a little topend. Any sugestions out there? What about XOs?
Hopefully Mark will have time to give us that update soon.
MB
I guess I have been out of touch with both this forum and with the driver status.
I discovered that the driver had sold out just yesterday . Since it is now gone, I will be removing the support documentation from my Web site. If anyone hears of a poly driver buyout to replace it please e-mail me.
In the meantime I have been continuing to work with the driver.
I have "tube" loaded tweeter designs using the Pioneer FB tweeter and the new rear mount PE ND20TB-4. Both are inexpensive tweeters in the 5 to 6 usd range.
As with two of the already posted designs the idea was to produce a "time-aligned" loudspeaker using a flat front baffle.
For the ND20TB-4 you use a 1/2 inch front baffle. The tweeter tube is 1/2 inch by 1 and 1/4 inches in diameter. It is formed by drilling a 1 and 1/4 inch hole in the baffle. Using the stock tweeter mounting screw holes I screwed the tweeter to the back of the baffle. The front of the tweeter is butted against the back of the baffle. The mounting tabs are away from the baffle. Don't overtighten the screws. Hopefully the tweeter will be centered around/behind the opening.
The driver center to center spacing is merely 3 and 1/4 inches. This close spacing produces a fairly even off axis response both veritcally and horizontally.
This has been an interesting project for me. I have learned much, both about aspects of driver design and about a new pathway for two-way designs.
Best,
Mark
I was going to post a tiny little GIF (in file size anyway) but just had an error message that the image was too large. So rather my trying to fool with image size and then have the image to small to read, e-mail me if you are interested and I will attach the image as a file. The image provided impulse response, frequency response and crossover schematic. If you want the GIF for the Pioneer tweeter, just say so and I will e-mail that too.
I discovered that the driver had sold out just yesterday . Since it is now gone, I will be removing the support documentation from my Web site. If anyone hears of a poly driver buyout to replace it please e-mail me.
In the meantime I have been continuing to work with the driver.
I have "tube" loaded tweeter designs using the Pioneer FB tweeter and the new rear mount PE ND20TB-4. Both are inexpensive tweeters in the 5 to 6 usd range.
As with two of the already posted designs the idea was to produce a "time-aligned" loudspeaker using a flat front baffle.
For the ND20TB-4 you use a 1/2 inch front baffle. The tweeter tube is 1/2 inch by 1 and 1/4 inches in diameter. It is formed by drilling a 1 and 1/4 inch hole in the baffle. Using the stock tweeter mounting screw holes I screwed the tweeter to the back of the baffle. The front of the tweeter is butted against the back of the baffle. The mounting tabs are away from the baffle. Don't overtighten the screws. Hopefully the tweeter will be centered around/behind the opening.
The driver center to center spacing is merely 3 and 1/4 inches. This close spacing produces a fairly even off axis response both veritcally and horizontally.
This has been an interesting project for me. I have learned much, both about aspects of driver design and about a new pathway for two-way designs.
Best,
Mark
I was going to post a tiny little GIF (in file size anyway) but just had an error message that the image was too large. So rather my trying to fool with image size and then have the image to small to read, e-mail me if you are interested and I will attach the image as a file. The image provided impulse response, frequency response and crossover schematic. If you want the GIF for the Pioneer tweeter, just say so and I will e-mail that too.
For Graeme and anyone else interested,
As an arbitrary point of reference, the three two-way designs using the 299-145 driver will remain on my Web site until July 15, 2005.
On that date I plan to delete the projects using the 299-145 driver.
I hope to have another project to replace it by then.
In post 40 and 41, MB spoke of comparing the sound of the modified and unmodified driver. Just a couple of points. First, acoustical listening tests can be very complicated to pull off. The reason being that our brains are involved in the process.
For example, in the absence of time clues our brains fix stereo location (source location) based upon volume. This is how most pop recordings work. Everything is recorded mono and then panned or mixed for stereo. The brain is very sensitive to even small differences in level to assign location. Using a mono source, MB had nothing but level to go on. And MB's brain easily identified the loudspeaker that was louder, and then so fixed on that that he thought the other loudspeaker was not even voicing.
Next, the vertical to horizontal alignment thing is based upon the idea of how people listen to loudspeakers. People are more likely to move across the horizontal plane and not jump up and down or sit and stand repeatedly while listening to music. Because of this assumption, the rule-of-thumb is to vertically align and not horizontally align. If, however, you do not move while listening, then either work just as well. It is only when the listener moves that their are differences. Even then, with good design, it is possible to so minimize the "problem" that either will work. Very close spacing and time aligment of drivers are the design elements that will minimize the problem.
Of course, if you do go horizontal you will have all of the arrogant ignorant telling you that you are an idiot for doing it that way. But then, you aren't the one who is the idiot.
Best,
Mark
As an arbitrary point of reference, the three two-way designs using the 299-145 driver will remain on my Web site until July 15, 2005.
On that date I plan to delete the projects using the 299-145 driver.
I hope to have another project to replace it by then.
In post 40 and 41, MB spoke of comparing the sound of the modified and unmodified driver. Just a couple of points. First, acoustical listening tests can be very complicated to pull off. The reason being that our brains are involved in the process.
For example, in the absence of time clues our brains fix stereo location (source location) based upon volume. This is how most pop recordings work. Everything is recorded mono and then panned or mixed for stereo. The brain is very sensitive to even small differences in level to assign location. Using a mono source, MB had nothing but level to go on. And MB's brain easily identified the loudspeaker that was louder, and then so fixed on that that he thought the other loudspeaker was not even voicing.
Next, the vertical to horizontal alignment thing is based upon the idea of how people listen to loudspeakers. People are more likely to move across the horizontal plane and not jump up and down or sit and stand repeatedly while listening to music. Because of this assumption, the rule-of-thumb is to vertically align and not horizontally align. If, however, you do not move while listening, then either work just as well. It is only when the listener moves that their are differences. Even then, with good design, it is possible to so minimize the "problem" that either will work. Very close spacing and time aligment of drivers are the design elements that will minimize the problem.
Of course, if you do go horizontal you will have all of the arrogant ignorant telling you that you are an idiot for doing it that way. But then, you aren't the one who is the idiot.
Best,
Mark
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