First off, this project is dedicated to the memory of Henry Darger, an American writer.
From wikipedia:
"In the Realms of the Unreal includes The Story of the Vivian Girls, in What is Known as the Realms of the Unreal, of the Glandeco-Angelinian War Storm Caused by the Child Slave Rebellion, and extends over 15 immense, densely-typed volumes of 15,145 total pages. The text is accompanied by three bound volumes of several hundred illustrations, scroll-like watercolor paintings on paper, the work of six decades, derived from magazines and coloring books."
[IMGDEAD]http://img714.imageshack.us/img714/3504/chiguidesolo.jpg[/IMGDEAD]
Violet is one of the Vivian Girls, after which this project is named. Digital signal processing (DSP) plays a central part to this also - hence Violet DSP. Its got a nice ring to it.
This project started several years ago - really though, it is the evolution of my interest in sound reproduction. Before I describe the goals and current results of this project, I'll share a little about how I got here.
I was originally turned on to the 'hi-fi' world by a friend taking me to a fancy gear shop one day. I think we were listening to Muddy Waters on electrostats, IIRC. Definitely kind of mind-blowing. I knew I could do the same on my own, DIY, and luckily I eventually found diyAudio.
I initially bought a pair of Acoustic Energy Aegis 1 loudspeakers. They weren't too bad really. Small, budget, and limited speakers, but focused on doing the midrange justice.
I then bought a used pair of original Advent speakers - they were interesting, but nothing extraordinary. I didn't know what I was looking for, I guess.
Somehow, then, I got lucky and stumbled on SL's Plutos. They are omni speakers, and in them I found I think what others have - that the polar radiation pattern matters, a lot. I think I really appreciated Linkwitz's down to earth practicality combined with his extensive technical knowledge. I don't use the Plutos much these days, mostly because I feel they were superseded in many ways by my more recent speakers - but I don't know if any speaker so far has the same super smooth presentation, all due to a very very regular polar pattern, IMO. I actually haven't updated the EQ to version 2.1, which might make all the difference to my using them more. I hope to sometime soon. The comparison then should be very interesting. One thing I think though, is that omni may present more ambient information than I like - too high a ratio of reflected to direct sound. We'll see - but I currently feel dipoles have the right balance for me.
One thing though, is that the Plutos have relativity complicated electronics driving them. I wanted to see what was capable at the other end of the spectrum, so I built single driver, no crossover Zigmahornets with DCA4 drivers. They were interesting, educational, but ultimately, unlistenable. Very precise imaging, but nothing going on below 200Hz, and seriously irregular highs. I sold them eventually.
At the same time, I wanted to see what a 'classic' design could do - a boxed speaker, with a well done crossover, good bass, good mids, good highs. I chose Zaph's BAMTMs, and made the floorstanding version. These were also very educational, and I still enjoy listening to them. They are very well done speakers, but the mild off axis irregularity in the mid-treble region becomes easily recognizable compared to something like the Pluto. Similarly, their 'box sound' is very obvious compared to omni and dipole speakers. They are still for sale, if anyone in SoCal is interested. So after having a number of different speakers, it was becoming obvious what was important (to me) - especially, how audible off axis radiation is.
I then dove into my first open baffle (OB) speaker. I wanted to keep it simple, and bought a pair of Visaton B200 8" drivers. I definitely didn't know what physical parameters matter in OB systems, but the B200 were regarded as very good full range, OB speakers. And they are (were). After all these different speakers, and endless tweaking I did, using B200s OB was the first time my girlfriend (now wife) said she liked what she heard, and thought it was an improvement. A good sign. I too, liked what I heard.
In hindsight, after learning a lot more about OB speaker systems, I can say that there is a lot 'wrong' with using just a single, 8" driver (no bass, beaming highs, good midrange, but not fully regular off axis response, power/displacement limitations). Not long after getting the B200s up and running, I decided to dive into an OB woofer - and selected MJK's Alpha15a H-frame design. Here is a picture of a very early version of the pairing - note the centered, circular, cardboard baffle for the B200. A no-no now. I was just beginning to develop my measurement setup, which was an invaluable step to learning what is going on with audio, speakers, etc. Here are some more interesting tidbits on the Alpha15a H-frame.
Next I added a tweeter (a single, forward firing Dayton ND20FB), combined with a 10" rectangular baffle, similar to early Linkwitz Orion designs. The addition of a woofer and tweeter definitely took things to a more serious level - a truly fullrange speaker system. I was doing all XO and EQ in the computer at this point, using various software, and doing all my own measurements (which were fairly flawed, but still very necessary). I might add that the various pieces software I was using at the time were a serious PITA - nothing wanted to work together in a complicated chain of bits and pieces. Later, I'll write up what I use now, which is a million times easier, and way more powerful. It was also around this time that I spent a week living with a pair of SL's Orions, which was wonderful.
By this time, I was using my speakers as monitors for my audio recording hobby - I lived with a lot of musicians, and recorded a lot of their music - from acoustic ensembles to full blown, loud rock. One of the serious benefits of this was having heard the live event, and then trying to reproduce it as faithfully, and as engagingly over my speakers. But speaking of blown, one day my (expensive) B200 drives blew when listening to live drum recordings at live levels (b200s are only rated for 30W - definitely not enough). I then replaced them with Dayton RS225 drivers, but I was still learning. I soon abandoned these drivers, after figuring out they were also power limited, and also had polar regularity issues. They were replaced with Eminence Alpha6a drivers (a 6", very good driver IME), and then with smaller 4" drivers, ultimately the TangBand W4-1320sj.
[IMGDEAD]http://img35.imageshack.us/img35/4139/midsr.jpg[/IMGDEAD]
At the same time, I discovered the Neo3PDR dipole tweeter - and soon realized that this driver was way way better than either a single, forward firing tweeter, or back to back tweeters. I was continuing to discover the benefits of a regular polar response - in both the Neo3, and in the value of minimal baffle (aka none at all). In a recent thread, I've documented what it has taken for me to achieve a very regular off axis response in the midrange and treble, with regards to open baffle, dipole radiation.
Not long after adding the Neo3PDR tweeters, I designed a new woofer system - for lack of a better name, I call it the GWx4. I wanted something smaller to replace the bulky, low SAF, H-frame - so my goals for it were smaller size, inexpensive, higher SPL output, and possibly increased LF extension. I feel I met those goals, and retired the Alpha15a.
It was also around this time I read Floyd Toole's book, Sound Reproduction. Only someone with a large companies' resources could have conducted such an in depth study of what matters when it comes to quality sound reproduction. It is a must read! It very much stresses the importance of the off axis response, among many other invaluable studies.
That brings us up to the current time.
From wikipedia:
"In the Realms of the Unreal includes The Story of the Vivian Girls, in What is Known as the Realms of the Unreal, of the Glandeco-Angelinian War Storm Caused by the Child Slave Rebellion, and extends over 15 immense, densely-typed volumes of 15,145 total pages. The text is accompanied by three bound volumes of several hundred illustrations, scroll-like watercolor paintings on paper, the work of six decades, derived from magazines and coloring books."
[IMGDEAD]http://img714.imageshack.us/img714/3504/chiguidesolo.jpg[/IMGDEAD]
Violet is one of the Vivian Girls, after which this project is named. Digital signal processing (DSP) plays a central part to this also - hence Violet DSP. Its got a nice ring to it.
This project started several years ago - really though, it is the evolution of my interest in sound reproduction. Before I describe the goals and current results of this project, I'll share a little about how I got here.
I was originally turned on to the 'hi-fi' world by a friend taking me to a fancy gear shop one day. I think we were listening to Muddy Waters on electrostats, IIRC. Definitely kind of mind-blowing. I knew I could do the same on my own, DIY, and luckily I eventually found diyAudio.
I initially bought a pair of Acoustic Energy Aegis 1 loudspeakers. They weren't too bad really. Small, budget, and limited speakers, but focused on doing the midrange justice.
I then bought a used pair of original Advent speakers - they were interesting, but nothing extraordinary. I didn't know what I was looking for, I guess.
Somehow, then, I got lucky and stumbled on SL's Plutos. They are omni speakers, and in them I found I think what others have - that the polar radiation pattern matters, a lot. I think I really appreciated Linkwitz's down to earth practicality combined with his extensive technical knowledge. I don't use the Plutos much these days, mostly because I feel they were superseded in many ways by my more recent speakers - but I don't know if any speaker so far has the same super smooth presentation, all due to a very very regular polar pattern, IMO. I actually haven't updated the EQ to version 2.1, which might make all the difference to my using them more. I hope to sometime soon. The comparison then should be very interesting. One thing I think though, is that omni may present more ambient information than I like - too high a ratio of reflected to direct sound. We'll see - but I currently feel dipoles have the right balance for me.
One thing though, is that the Plutos have relativity complicated electronics driving them. I wanted to see what was capable at the other end of the spectrum, so I built single driver, no crossover Zigmahornets with DCA4 drivers. They were interesting, educational, but ultimately, unlistenable. Very precise imaging, but nothing going on below 200Hz, and seriously irregular highs. I sold them eventually.
At the same time, I wanted to see what a 'classic' design could do - a boxed speaker, with a well done crossover, good bass, good mids, good highs. I chose Zaph's BAMTMs, and made the floorstanding version. These were also very educational, and I still enjoy listening to them. They are very well done speakers, but the mild off axis irregularity in the mid-treble region becomes easily recognizable compared to something like the Pluto. Similarly, their 'box sound' is very obvious compared to omni and dipole speakers. They are still for sale, if anyone in SoCal is interested. So after having a number of different speakers, it was becoming obvious what was important (to me) - especially, how audible off axis radiation is.
I then dove into my first open baffle (OB) speaker. I wanted to keep it simple, and bought a pair of Visaton B200 8" drivers. I definitely didn't know what physical parameters matter in OB systems, but the B200 were regarded as very good full range, OB speakers. And they are (were). After all these different speakers, and endless tweaking I did, using B200s OB was the first time my girlfriend (now wife) said she liked what she heard, and thought it was an improvement. A good sign. I too, liked what I heard.
In hindsight, after learning a lot more about OB speaker systems, I can say that there is a lot 'wrong' with using just a single, 8" driver (no bass, beaming highs, good midrange, but not fully regular off axis response, power/displacement limitations). Not long after getting the B200s up and running, I decided to dive into an OB woofer - and selected MJK's Alpha15a H-frame design. Here is a picture of a very early version of the pairing - note the centered, circular, cardboard baffle for the B200. A no-no now. I was just beginning to develop my measurement setup, which was an invaluable step to learning what is going on with audio, speakers, etc. Here are some more interesting tidbits on the Alpha15a H-frame.
Next I added a tweeter (a single, forward firing Dayton ND20FB), combined with a 10" rectangular baffle, similar to early Linkwitz Orion designs. The addition of a woofer and tweeter definitely took things to a more serious level - a truly fullrange speaker system. I was doing all XO and EQ in the computer at this point, using various software, and doing all my own measurements (which were fairly flawed, but still very necessary). I might add that the various pieces software I was using at the time were a serious PITA - nothing wanted to work together in a complicated chain of bits and pieces. Later, I'll write up what I use now, which is a million times easier, and way more powerful. It was also around this time that I spent a week living with a pair of SL's Orions, which was wonderful.
By this time, I was using my speakers as monitors for my audio recording hobby - I lived with a lot of musicians, and recorded a lot of their music - from acoustic ensembles to full blown, loud rock. One of the serious benefits of this was having heard the live event, and then trying to reproduce it as faithfully, and as engagingly over my speakers. But speaking of blown, one day my (expensive) B200 drives blew when listening to live drum recordings at live levels (b200s are only rated for 30W - definitely not enough). I then replaced them with Dayton RS225 drivers, but I was still learning. I soon abandoned these drivers, after figuring out they were also power limited, and also had polar regularity issues. They were replaced with Eminence Alpha6a drivers (a 6", very good driver IME), and then with smaller 4" drivers, ultimately the TangBand W4-1320sj.
[IMGDEAD]http://img35.imageshack.us/img35/4139/midsr.jpg[/IMGDEAD]
At the same time, I discovered the Neo3PDR dipole tweeter - and soon realized that this driver was way way better than either a single, forward firing tweeter, or back to back tweeters. I was continuing to discover the benefits of a regular polar response - in both the Neo3, and in the value of minimal baffle (aka none at all). In a recent thread, I've documented what it has taken for me to achieve a very regular off axis response in the midrange and treble, with regards to open baffle, dipole radiation.
Not long after adding the Neo3PDR tweeters, I designed a new woofer system - for lack of a better name, I call it the GWx4. I wanted something smaller to replace the bulky, low SAF, H-frame - so my goals for it were smaller size, inexpensive, higher SPL output, and possibly increased LF extension. I feel I met those goals, and retired the Alpha15a.
It was also around this time I read Floyd Toole's book, Sound Reproduction. Only someone with a large companies' resources could have conducted such an in depth study of what matters when it comes to quality sound reproduction. It is a must read! It very much stresses the importance of the off axis response, among many other invaluable studies.
That brings us up to the current time.
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). I guess computers add a degree of instability, but my turntable isn't even close to working these days. I guess there isn't a lot to be gained in going analog. (Similarly, analog active boards with lots of opamps can have high noise floors.) Pick your poison, I guess.
