tomcat9,
I have not seen any prior indication of Ai being out of business, and cannot stand seeing any company discredited without a chance to defend themselves. If gedlee simply expressed that Ai was out of business, I would not have said a word unless I discovered the contrary. I even recall that gedlee mentioned he could still get parts from Ai.
I have not seen any prior indication of Ai being out of business, and cannot stand seeing any company discredited without a chance to defend themselves. If gedlee simply expressed that Ai was out of business, I would not have said a word unless I discovered the contrary. I even recall that gedlee mentioned he could still get parts from Ai.
Songsc and Bryce
Nobody is discrediting Ai. I have every reason to want them to suceed as it is my money that is lost. I AM Ai, I own 1/2 of the company, but the fact is that they can't seem to get it together to ship products. I can get "parts" from Ai and have, but they have not been reliable, and people have rejected the parts quality. What I make now are better - I should know I designed all the products, all the manufacturing, everything for both locations.
When I was going out there they could build samples, even mass produce had they been able to buy the parts, but when they weren't able to even pay my expenses flying back and forth I had to stop going. Now I have serious questions about their ability to make the product without me there. Much as I would like nothing better than for Ai to be healthy the fact is that they are not. I only know what I am told and I am told that they haven't sold any speakers in about a year.
Nobody is discrediting Ai. I have every reason to want them to suceed as it is my money that is lost. I AM Ai, I own 1/2 of the company, but the fact is that they can't seem to get it together to ship products. I can get "parts" from Ai and have, but they have not been reliable, and people have rejected the parts quality. What I make now are better - I should know I designed all the products, all the manufacturing, everything for both locations.
When I was going out there they could build samples, even mass produce had they been able to buy the parts, but when they weren't able to even pay my expenses flying back and forth I had to stop going. Now I have serious questions about their ability to make the product without me there. Much as I would like nothing better than for Ai to be healthy the fact is that they are not. I only know what I am told and I am told that they haven't sold any speakers in about a year.
Good question - I was meaning to update the status.
I've had a serious failure of the molds. The center of the mold is alluminum - no problems, but the outside, for convenience, is made of steel. To keep the steel from oxidizing it was painted. The paint was a very bad idea. Initially it was not so bad, I made about a dozen or more waveguides. But as time went on the mold began to stick. It kept getting worse and worse until I could no longer get the waveguides out of the mold without having to break out the part.
Hence, I have had to remove all of the paint and use a different rear mold which has a RTV sleeve. I am almost done with this for the 10" and I can start making those again. After that I will correct the 12" mold.
I completed the crossver for the Abbey and once the mold is corrected I can begin making those. However, I will probably have John make the parts from the get-go, so that will delay the Abbeys several weeks until I get the parts from John. But that way they will all be high quality cut parts.
Hope this helps.
I've had a serious failure of the molds. The center of the mold is alluminum - no problems, but the outside, for convenience, is made of steel. To keep the steel from oxidizing it was painted. The paint was a very bad idea. Initially it was not so bad, I made about a dozen or more waveguides. But as time went on the mold began to stick. It kept getting worse and worse until I could no longer get the waveguides out of the mold without having to break out the part.
Hence, I have had to remove all of the paint and use a different rear mold which has a RTV sleeve. I am almost done with this for the 10" and I can start making those again. After that I will correct the 12" mold.
I completed the crossver for the Abbey and once the mold is corrected I can begin making those. However, I will probably have John make the parts from the get-go, so that will delay the Abbeys several weeks until I get the parts from John. But that way they will all be high quality cut parts.
Hope this helps.
Thank you yes it does help. Quite frankly, I'm getting more and more sick of the dynamic capabilities of my speakers, so I'm getting a little impatient (not your problem of course).
What is an RTV sleeve (I dont know a lot about mold making, just curious), and will it change the actual final product at all? Sorry to hear about the failure by the way, I know that this can be frustrating. After spending most of the summer coding video's for my my dissertation project I found a pretty major flaw in the data caused by the coding software. Once I developed a solution, or so I thought, this was followed by a new set of problems. I then discovered solutions for these only to have the motherboard and power supply die in the main coding computer. Delays in my PhD aren't going to come from me dragging my feet, its going to be equipment failure I think.
I read your comments about using the Abbey as a center and possibly modifying the crossover. Now that you have a final crossover I would love to see a schematic. I'm curious your general design direction. What sort of modifications would you make?
While I know you don't like the term baffle step compensation, and the more I learn about it, the more I understand why, I still assume you design these to have a relatively smooth and even response without the boundary compensation you would get if it was against a wall. In other words, I imagine that if I was to mount this directly against a wall it would be a bit too bass heavy. The only modification I could think of that would really be useful would simply be to correct for the excess bass you would get if mounted too close to a wall. While I understand that its generally a compromise to stick a speaker that close to the wall (I say generally, not always), I think its often necessary when people mount the speakers behind or directly under the screen.
In my own setup I have the center currently sitting below and in front of the screen, roughly 2 feet from the rear wall, while the side speakers are more like 4 feet from the rear wall. It's still not very ideal, but it gets the job done. The center image is clearly more identifiable than the left and right images, and so voices tend to fall as they move toward the center of the screen. I've also noticed that a lot of movies have the primary sound source at the top of the screen, not bottom, but I don't want to mount a center that high (12 feet off the ground or so).
What is an RTV sleeve (I dont know a lot about mold making, just curious), and will it change the actual final product at all? Sorry to hear about the failure by the way, I know that this can be frustrating. After spending most of the summer coding video's for my my dissertation project I found a pretty major flaw in the data caused by the coding software. Once I developed a solution, or so I thought, this was followed by a new set of problems. I then discovered solutions for these only to have the motherboard and power supply die in the main coding computer. Delays in my PhD aren't going to come from me dragging my feet, its going to be equipment failure I think.
I read your comments about using the Abbey as a center and possibly modifying the crossover. Now that you have a final crossover I would love to see a schematic. I'm curious your general design direction. What sort of modifications would you make?
While I know you don't like the term baffle step compensation, and the more I learn about it, the more I understand why, I still assume you design these to have a relatively smooth and even response without the boundary compensation you would get if it was against a wall. In other words, I imagine that if I was to mount this directly against a wall it would be a bit too bass heavy. The only modification I could think of that would really be useful would simply be to correct for the excess bass you would get if mounted too close to a wall. While I understand that its generally a compromise to stick a speaker that close to the wall (I say generally, not always), I think its often necessary when people mount the speakers behind or directly under the screen.
In my own setup I have the center currently sitting below and in front of the screen, roughly 2 feet from the rear wall, while the side speakers are more like 4 feet from the rear wall. It's still not very ideal, but it gets the job done. The center image is clearly more identifiable than the left and right images, and so voices tend to fall as they move toward the center of the screen. I've also noticed that a lot of movies have the primary sound source at the top of the screen, not bottom, but I don't want to mount a center that high (12 feet off the ground or so).
The sleeve won't change anything in the final product. Its just a liner on the back mold to keep this part from sticking to the casting. The RTV won't stick to anything - it cures with a sort of oily film on it - silicoln I believe it is.
E-mail me and I can send you the crossover topology.
I do design the systems to be flat in a free field. So there can be some tendancy to have an accentuated bass when placed against a wall. Multiple subs would help this, but a little bass roll-off might be in order too. Generally people prefer a slight bass accentuation, especially if the listening levels are on the low side.
E-mail me and I can send you the crossover topology.
I do design the systems to be flat in a free field. So there can be some tendancy to have an accentuated bass when placed against a wall. Multiple subs would help this, but a little bass roll-off might be in order too. Generally people prefer a slight bass accentuation, especially if the listening levels are on the low side.
Hey Dr. Geddes did you get my email? I asked about the schematic and such? Let me know and I will send another email.
I've been wondering about two things you probably have covered. So you talked once before about surrounds, and I started thinking about a new surround project similar to the fronts. I was thinking about going with an 8" B&C driver, either the 8NDL51 or 8PS21 and a smallish horn loaded driver. I recall you saying you could do some better pricing on the drivers, so we should talk about that one.
Now as for the tweeter, I'm pretty up in the air. If I go with a large 90 degree round waveguide I would end up with a 16" or larger enclosure. given that this is a small flat wall mounted job, thats a bit unreasonable. I know you liked the idea of a coax, but I tried out an 18sound unit, and I couldn't get a decent response, and found it sounded very "strange" off axis. I'm sure it could be an option, but I wasn't a fan with my initial time with it. They also are all very deep, and I want to make this a flat wall mount design of less than 6" if possible. So how about an oval or rectangular shaped wave guide?
The other thing I'm wondering about is the foam you use. Can you either point me in the right direction or sell me some to use. You mentioned using it to dampen ports as well. I'd like to play around with this in my subs. I'm also wondering if some improvements could be had with the coax if I was to cut a piece for that.
I've been wondering about two things you probably have covered. So you talked once before about surrounds, and I started thinking about a new surround project similar to the fronts. I was thinking about going with an 8" B&C driver, either the 8NDL51 or 8PS21 and a smallish horn loaded driver. I recall you saying you could do some better pricing on the drivers, so we should talk about that one.
Now as for the tweeter, I'm pretty up in the air. If I go with a large 90 degree round waveguide I would end up with a 16" or larger enclosure. given that this is a small flat wall mounted job, thats a bit unreasonable. I know you liked the idea of a coax, but I tried out an 18sound unit, and I couldn't get a decent response, and found it sounded very "strange" off axis. I'm sure it could be an option, but I wasn't a fan with my initial time with it. They also are all very deep, and I want to make this a flat wall mount design of less than 6" if possible. So how about an oval or rectangular shaped wave guide?
The other thing I'm wondering about is the foam you use. Can you either point me in the right direction or sell me some to use. You mentioned using it to dampen ports as well. I'd like to play around with this in my subs. I'm also wondering if some improvements could be had with the coax if I was to cut a piece for that.
noah katz said:
Last night I watched Star Wars III on my DLP with the Summas.
WOW!
That movie must have the most dynamic range of anything I've ever watched. I don't know what kind of special sauce Lucasfilm is using, but that flick gave the Summas a *serious* workout. I was actually getting worried that the subs might blow up, since a pair of subs has a heck of a time keeping up with the mains. I'd planned on finishing a 3rd sub, but now I'm wondering if I should go to four. Movies like that can certainly use all the headroom you can throw at them.
To make a long story short, if you're using these for music exclusively, you owe it to yourself to watch a movie (or three) with them. It's quite an experience.
Actually I am arround this morning - but not last night.
For the surrounds I intend to use just the 8" drivers full range. I don't see the need or advantage of a waveguide for the surrounds. Imaging is not an issue, etc. I don't see what is gained for all the space and cost added.
I am not sure that I did get your E-mail, you should mail me again, but clearly I don't want to be a distributor of small quantities of foam, its just too much trouble. You need to understand that stuff is expensive. I would sell a block worth about $100 (about 3 ft^3), less than that would be worth it to me. If you want it cut, thats another thing altogether.
For the surrounds I intend to use just the 8" drivers full range. I don't see the need or advantage of a waveguide for the surrounds. Imaging is not an issue, etc. I don't see what is gained for all the space and cost added.
I am not sure that I did get your E-mail, you should mail me again, but clearly I don't want to be a distributor of small quantities of foam, its just too much trouble. You need to understand that stuff is expensive. I would sell a block worth about $100 (about 3 ft^3), less than that would be worth it to me. If you want it cut, thats another thing altogether.
Patrick
You are quite correct, films like that is where the speakers shine. You are NOT going to get that kind of sound playback from Bose cubes or any of the other Home Theater speaker setups. It takes a lot of speakers to do Lucas films.
George Lucas once said "Sound is half of the movie experience". How many people spend half of their HT budget on the sound?
I used to use Star Wars I as a demo for my theater. Now I tend to use "Phantom" in Blue Ray.
You are quite correct, films like that is where the speakers shine. You are NOT going to get that kind of sound playback from Bose cubes or any of the other Home Theater speaker setups. It takes a lot of speakers to do Lucas films.
George Lucas once said "Sound is half of the movie experience". How many people spend half of their HT budget on the sound?
I used to use Star Wars I as a demo for my theater. Now I tend to use "Phantom" in Blue Ray.
While I know I am a minority here, about 80% of my budget went to sound. In fact, up until this past year, it was considerably more. My DIY amplifiers are a little silly, so I don't know that there cost is all that fair, and they are DIY, so retail on a production version would cost who knows how much. Anyway, I would say I have roughly 1500 into my amplifiers, roughly 1200 into my pre/pro, currently about 4000 in speakers, but since I'm about to spend 3300 with you, that will change that a little (I will sell the old center to recoup some of that, and the L-R mains are dead), I use a PS3 as one source, and an OPPO 983 as the other, so thats what like 800 there, and then the three subwoofers I currently have probably total 2-3000. For the sake of argument lets say I have 10,000 spent on my sound specific to theater use (I have a vinyl rig too, but thats not used for movies). I bought a used Yamaha LPT-510 projector for 500 dollars with 300 hours on the bulb and an Ebay special electric 100" screen, which I refinished with a high contrast silver finish, for a total of 300. That means I spent less than 1000 on the video portion, maybe you could add 400, split the cost of the video sources between sound and video, make it 1300. From that standpoint its less than 12 percent of my total budget. I've been more into the sound for a while now, and always spent considerably more on sound than video.
It will be a while, but at some point I do intend to buy a new 1080p projector with better blacks, contrast, etc. I also will probably go with a different screen setup, but really, this screen offers impressive picture to me, and I have seen among the best (Vidikron, Runco, Sony Pearl). Maybe if I graduate soon and get the most amazing professorship, land a huge research grant, and get an unheard of pay bonus, I could afford to buy a Sony 4K projector and 200" screen. Ah the dreams we have.
It will be a while, but at some point I do intend to buy a new 1080p projector with better blacks, contrast, etc. I also will probably go with a different screen setup, but really, this screen offers impressive picture to me, and I have seen among the best (Vidikron, Runco, Sony Pearl). Maybe if I graduate soon and get the most amazing professorship, land a huge research grant, and get an unheard of pay bonus, I could afford to buy a Sony 4K projector and 200" screen. Ah the dreams we have.
"For the surrounds I intend to use just the 8" drivers full range. I don't see the need or advantage of a waveguide for the surrounds."
I presume pjpoes and you mean 8" coaxials, so I'm not sure why you're talking tweeters/WG's, as they comes with compression drivers and use the cone as a WG.
And isn't CD desirable for surrounds, especially when oriented for indirect sound where what you hear is essentially the power response?
I presume pjpoes and you mean 8" coaxials, so I'm not sure why you're talking tweeters/WG's, as they comes with compression drivers and use the cone as a WG.
And isn't CD desirable for surrounds, especially when oriented for indirect sound where what you hear is essentially the power response?
based on what he has said earlier, I believe Dr. Geddes does not mean a coaxial, he actually means just using an 8" driver full range as the surround. This is actually very common in professional theaters and isn't very expensive to implement. While I agree with many things Dr. Geddes says, I happen to think that newer movie soundtracks and especially newer surround format technologies have brought greater demand onto surround speakers. I do think that surrounds should be somewhat more full range, going from say 80hz to 15-20khz. I also think think that having a smooth off-axis response would be a good thing in this case, but I really have no basis for this, as I haven't made speakers like this and compared them with a full range 8" or my own M&K cloned tripoles. I do agree with him that surrounds should not call attention to themselves, and I do find that to be a problem with many current offerings.
As for what I was talking about, I was talking about both coaxials and an actual setup with an 8" driver and separate waveguide and tweeter/driver. A friend of mine asked if I would build him a coincident source speaker for use in his home studio, and while I pleaded with him to go another route, he was insistent. It gave me a chance to try the 18sound 8" coaxial, and I tried them as surrounds for a night, and didn't like the final results. I didn't like the sound of the speakers either though, so who knows. My friend was happy, so I guess thats all that matters, right? The problem I had was that the response was not very controlled off-axis, and the coax design was causing a lot of response anomalies that were very audible. I used traps and notch filters to fix the major ones, but I didn't want to build an overly complex crossover to fix problems inherent in the design. I actually wonder if placing some foam, like Dr. Geddes uses in his horns, into the center of the coax would improve things any? On a positive note it was one of the more effortless and coherent speakers I have heard, which you would expect, but it just wasn't very natural sounding.
As for what I was talking about, I was talking about both coaxials and an actual setup with an 8" driver and separate waveguide and tweeter/driver. A friend of mine asked if I would build him a coincident source speaker for use in his home studio, and while I pleaded with him to go another route, he was insistent. It gave me a chance to try the 18sound 8" coaxial, and I tried them as surrounds for a night, and didn't like the final results. I didn't like the sound of the speakers either though, so who knows. My friend was happy, so I guess thats all that matters, right? The problem I had was that the response was not very controlled off-axis, and the coax design was causing a lot of response anomalies that were very audible. I used traps and notch filters to fix the major ones, but I didn't want to build an overly complex crossover to fix problems inherent in the design. I actually wonder if placing some foam, like Dr. Geddes uses in his horns, into the center of the coax would improve things any? On a positive note it was one of the more effortless and coherent speakers I have heard, which you would expect, but it just wasn't very natural sounding.
noah katz said:
Based on the current situation that I see in film, I don't see any reason to be concerned with "image" in the surrounds. They should (although this is debatable and probably not even consistant in the film audio mix) be difuse (no real direct sound content) and need not have a flat power response. I find that the sagging power response of the surrounds in a small home theater adds to the perception of them being farther away as this is a que to the perception of distance. So for ease, practicality and the lack of need of high performance I still see a full range driver (two actually as I use them back to back in a dipole configuration) as, if not ideal, certainly acceptable.
I just want to write a note about three 15" wavguides that were delivered from Gedlee today.
They are actually bigger than 15". More like 17". The visual finish is not high enough to mount them untreated in a speaker, but that was not what I had expected either. They need to be countersinked into the baffle, and need some putty and sanding since the edges of the waveguide are a bit rugged and not completely regular. But after doing this, they should be just fine estethically.
The mounting plates are drilled with very high precision. The throat transition waveguide<->mountingplate<->compressiondriver makes a smooth, perfect fit. The foamplugs also fits very well into the waveguides and has a nice exterior roundover.
All in all I'm very satisfied with the mechanical design and finish of this product.
They are actually bigger than 15". More like 17". The visual finish is not high enough to mount them untreated in a speaker, but that was not what I had expected either. They need to be countersinked into the baffle, and need some putty and sanding since the edges of the waveguide are a bit rugged and not completely regular. But after doing this, they should be just fine estethically.
The mounting plates are drilled with very high precision. The throat transition waveguide<->mountingplate<->compressiondriver makes a smooth, perfect fit. The foamplugs also fits very well into the waveguides and has a nice exterior roundover.
All in all I'm very satisfied with the mechanical design and finish of this product.
I talked with my fiberglass supplier and he is going try and improve the edge.
Waveguides should always be countersunk. It would be bad design to use a nice smooth outer radius and then leave the edge in a step. I also wouldn't use screws unless they are counter sunk and filled, but then why not just use glue. Adhesives today are miraculous substances. Not like the days of old. I use adhesive whenever possible.
Fine finishes could be put on those waveguides if that were desirable, its just that I have always painted them so the fabricator knows that surface finish is not a priority with me.
I'm also going to post that I can modify these devices for any throat size on request - at a little higher cost. Its just a different cast at the throat and a different sized mounting plate.
Waveguides should always be countersunk. It would be bad design to use a nice smooth outer radius and then leave the edge in a step. I also wouldn't use screws unless they are counter sunk and filled, but then why not just use glue. Adhesives today are miraculous substances. Not like the days of old. I use adhesive whenever possible.
Fine finishes could be put on those waveguides if that were desirable, its just that I have always painted them so the fabricator knows that surface finish is not a priority with me.
I'm also going to post that I can modify these devices for any throat size on request - at a little higher cost. Its just a different cast at the throat and a different sized mounting plate.
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