Greeting once again folks, okay here is the plan, until I can obtain the big machine I will forge ahead with the alternative. Which is to borrow the crossover from another speaker and design and build the cabinet, fully time aligned and mirror imaged. This way all that will have to be done is to construct the new crossover and then compare the two side by side. As fate dictates this model will just so happen to be right in the middle of the two speakers I had originally intended to design and construct, the 4 or 8 way systems. The reason being that the borrowed crossover is a five way system that I have added a 15" sub woofer and sub woofer crossover to making it a six way system, the photo shows all the parts except the 1 " dome tweeter which has not arrived yet. After having examined the borrowed crossover very closely their is no way anyone could know what was going through this guys mind to be able to design and construct such an apparatus as this. The amazing thing is that it actually worked, and there is no speaker at any price today that can compare with the sound and sophistication of this one. The most difficult aspect of this current project will be the location of the crossover, putting it inside the cabinet is impractical because it produces heat which should be vented along with disruptions from magnetic fields and placing it outside posses a risk that it could get damaged for a number of reasons. But I will think of something. This could easily take a couple of months to achieve so until then have a safe day.

Greeting once again, after further study i have learned that you really can't just wind up an inductor and throw it on a $100 meter and get an accurate reading. Its more like do the calculations to make your inductor, wire it up to your circutry, turn it up to full volume, and then test your reading on a $4000 or more machine and if you don't get the numbers back that you were hoping for start over. Well lets say that if you were starting from scratch and wanted to make the big 8 or 10 driver system you could probably spend a life time designing, finding the parts and testing the thing and then you would still have to find the time to actually build the speakers, market and sell them. So we are going to have to take another approach since there is no support from the family on this project and right now I dont have the finances to buy the machine and begin a lab of my own.
Things to be considered are do you want to just try and recreate the sound of the past (which by the way is still over the top of many of today speakers) or try to improve somehow on that same concept while still making them user friendly. And what I mean by user friendly is making them so they can be easiler transported and something that you don't need a mansion to hear properly, again this is no easy task but I believe can still be accomplished. Below are some old speaker inductors I picked up,most of which have no values attached and most of which I have no idea where they came from, but I will toy around with them and build some circutry. Then listen to them and either find a lab that can test the values, or a job in a lab devoted to finishing the project, or find some investors that would prefer to start a lab, or wait until I can save enough money to get the machine needed to read the values. This could take some time or I could get lucky and things might speed up quickly, if you know anyone or are interested yourself in helping to further this project contact me at mvcproducts.com where these speakers will first be offered to the public upon completion, and we can make a deal. Until further notice have a good day.

This is the crossover of the 1970's, the circular objects are the inductors, five of them, the other parts are resistors and capacitors. These are not the only inductors i have seen like this. And the only thing I can think of is that most of them are just copycats of the orignal 1970's version.

Good day folks. This is my favorite month of the decade, but you need not be concerned about that. I was hoping to show you some crossover technology from the 1970's but I seem to have lost that file. Anyway it was a 5 way speaker that had been crossed over at a 6db/oct rate and toned down with a bunch of resistors. The pair sounded fantastic but I now wonder exactly how much they knew and how much was experimental and just sounded right. Because the dimensions of the inductors are completely different from the ones I am about to receive. Which makes me excited about what this 4 way system could sound like. Previously I had showed you a picture of what I thought would be a close version of a tweeter inductor, and the difference it made. Well that difference was at extremely hi volume where one ear was piercing and the other was not, at low volume you really could not tell much of a difference at all. These new inductors could produce off the charts at all volumes. Primarily because the people making inductors today have never done this before, it is new to them and they had to start from scratch, a rather enormous task especially for anyone not really knowing what they are doing, like possibly back in the 1970's or your average joe who is just winding up an inductor on his lath. Your ability to measure the inductance is only as good as your equipment. So we patiently wait for our precious inductors to be delivered knowing they should be far superior to anything in the past.

Hi all, today we have a picture of an unshielded tweeter inductor perhaps 2000 or 3000 Hz, ours is going to be cut off at 5000 Hz. But even this inductor placed in paralell has a dramatic effect on eliminating the harshness of the raw tweeter and does better than a resistor because the inductor acts as a resistor in addition to acting as an inductor. The other photo is an inductor being used in circutry, to complete a 24db/oct it would need 2 capacitors and another inductor and to fine tune it you would need to get the inductances correct and for our purposes wind it to 5000 Hz. I knew these inductors would be a major link in the success of this project and they were the first thing i began to investigate and the only thing i'm still waiting on. Have a good day.

TESTING

Hi folks, well, the pre-amp is back and the equipiment test was positive, power to spare. So with the cd player pluged into the tape input I tested the raw drivers, all eight of them. And with out having been lifted or time aligned or contained or crossedover they sounded pretty good, which tells me that all the equipment is working just fine and the speakers just need to be fine tuned. We are still waiting on the most crucial part, the inductors, which hopefully will be coming along soon. Until then have a blessed day.

Good day folks, it would seem that the law of supply and demand also works in reverse. Over time, if there is no demand there will be no supply, and that is exactly what we have here. These inductors are a very sophisicated, esoteric part not to be created by an amature. I found some fantastic people willing to take on the challenge and I can not thank them enough. When considering design there were an infinant number of choices between amount of drivers and crossover points ect. to construct a speaker. I decided that if you wanted a 2,3,4,or5 way speaker just make it a 4, and if you wanted a 6,7,8,9 or 10 way speaker just make it an 8, and that will be the focus of this blog for the forseeable future.

Design cont...

Design cont.

Greeting people, I finally found someone to make the inductors needed for testing, they are being made now. As you must trust the people and their work of the past you must also trust your equipment. I am using the famed hafler 500 amp and its companion the DH-101 preamp along with a cheap cd player. These have all arrived but they do have some age 25-30 years and the equipment test confirms this. I am going to start with the preamp and have it rebuilt like new, perform another equipment test and go from there. I hear all this talk about digital speakers, but they have been at it for awhile and I suspect they may be having difficulties reproducing varying magnetic fields digitally. So while they are doing that we shall forge ahead. That's all folks.

design cont....

Alright folks, I know we are like a week early, but, unless you want to do all the work yourself you must rely on and trust the work of the people that came before you. In this case, I do. We also can not thank the people enough for their tireless efforts of the past, for with out them none of this would be possible. There is a slight parts delay, you need to get as many of the parts correct the first time around so as to not lose ground later. This part happens to be the inductor which they say is a simple part but you have to understand how an inductor works in order get the right one and that's not so simple. The 24db/Oct device should be sufficient to fill a 20'x40' room and there are no forseeable problems associated with that. The commercial 48db/oct device is another story, it seems that the 48 numbers do not exist because of the degree of difficulty deriving the 24 numbers. So I shall attempt to extraplicate the 24 numbers and test that to hear if there is anything detectable to the human ear, or mabey a driver can pick up some differences at louder volumes.

Above is the enclosure that will be used for testing, the final design will be discussed later. I cut down some plywood and simply cut circles to match the drivers, well not so simply, you have to get the exact size hole the first time or try again. I burned through some lumber achieving that task. the location of the drivers is not exact but it is close and will be phase- arrayed in the end. So, when the time comes i'll get back to you with more.

begin design

Greetings, earlier I explained the sound one wants to hear from your audio system, now we shall attempt to do it. The first order of business are the equasions used to determine crossover frequency and your db/oct filter. These can all be found at the link provided at an earlier post, you may have to pay for and then chase some information but it can all be found. There are some considerations though, first being the actual driver impedance vs the rated impedance. Even though a speaker is rated at lets say 8 ohms the actual may be different say 6.5 or 7. You need the actual number in the equasion in order for the numbers to come out right. So that is what will be done next, purchase drivers for the speakers,check the resistance, and use those figures to design the crossover network, then purchase the parts and build the network. This may take 2 or 3 weeks but we will be ready for photos soon after that. Oh gees, look at what time it is, I need to run and catch a banquet. Have a good day.

Hi, as you can see I would prefer to remain anonomous. I will tell you that my name is Mark Chembrovich and I have a bachlor of science degree in engineering from a small mid-west liberal arts college. I am currently turning my attention to audio engineering and the development of advanced passive crossovers and speaker design.

A chain is only as strong as its weakest link. The same holds true when reproducing natural sound. From audios' infancy, through modern day improvement's like the transistor and compact disk, the speaker remains the last moving part and most inefficient link in the "reproduction of natural sound" chain.
So, lets focus on the speaker and more importantly the crossover network that filters sound through those individual speakers or drivers. Natural sound or sound as it is heard in nature can best be described with an orchestra. Imagine a full orchestra spread across a stage, if you sat in a good hearing position, and concentrated, you could hear each instrument coming from a particular point across the stage. This is the sound you want your audio system to deliver, a pair of multi driven speakers that do not just emanate sound from two points of origin, but the entire space between the speakers delivering the spread across stage sound of an orchestra. Achieving this goal is difficult but possible.
In order to understand this concept one must start with the frequency of sound, or hearing range, which is measured in hertz(hz). Humans can hear from 20 hz, the low end or bass, to 20,000 hz, the high end or tweeter, and everywhere in between. furthurmore the range is divided into octaves(Oct). An octave is derived by starting at 20 hz and doubling the number. This gives you 10 octaves in the human hearing range.
Now, the best sound reproductive system would consist of 10 drivers each delivering the sound of its own octave and only its own octave, verses one driver attempting to deliver the 10 octaves of the hearing range all at one time. The former is impractical in portable applications and the latter produces distortion by overworking the range of sound. The solution is to meet in the middle with a speaker that has 4 or 5 drivers to carry the 10 octaves and limit, or filter out sound, leaving only the sound designed to carried by each driver to be carried by that driver.
This bring us to the crossover network, The device used to filter sound. Sound is measured in decibels(db), whispers at a few db and loud sound being 100-150 db. The crossovers job is to filter out the hearing range not designed to carried by an individual driver, ie. only high sound through the tweeter driver, only low sound through the woofer driver, and mid sound through the midrange drivers. The problem with many home and concert speakers today is the efficiency of the crossover used to filter the sound through the drivers. This efficiency is measured in decibels/octave(db/Oct) or the amount os sound that leaks into the next octave above or below. A lot of speakers only filter 3or 6 db/Oct and at louder levels the range of sound is forced through drivers not designed to carry that range, producing distortion. The answer to this problem is to design a more efficient crossover network that filters 24 or 48 db/Oct allowing only the sound meant to be delivered by an individual driver, to actually be sent through that driver.
When designing crossover networks there are two basic choices, active and passive. Active networks separate the sound before the amplifier and the passive separate sound after the amp. The best active network that I have heard of only filters 12-18 db/Oct and at higher volume will still allow sound to leak through octaves, not to mention that these speakers are rather expensive. This is why I believe the passive network is more efficient but also requires more power in the amp to overcome the sound that is filtered out. In my opinion the best passive crossover filter is the butterworth filter design perfected by the linkwitz-Riley filter www.linkwitzlab.com/crossovers.htm which can reach limits to 48db/Oct. This limit however is best used commercially where high volume is a consideration. Home speakers are best when 4 or 5 drivers are phase-arrayed( drivers aligned at the source of inception) and filtered at 24 db/Oct, due to complications of available space required to mount the crossover device.
This is why I have undertaken the development of advanced passive crossovers, to offer the audiophile an opportunity to enjoy the reproduction of natural sound. If there is interest I will update this blog as to my progress on this issue.

The reproduction of natural sound, crossover networks, and speaker design

Are you interested in this subject? I will be posting more information soon and am just checking the responce.