Which picture shows more?
An externally hosted image should be here but it was not working when we last tested it.
Well, the picture on the left has one shadow that I can see. The one on the right has multiple. But that isn't the problem. Why in the world are these pics so small? Is it because I have a 22 inch monitor 
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Let's make the pictures BIGGER please. The picture on the left shows a little more detail, but I am really being anal here. Both pictures represent a fantabulastic loudspeaker and so, sonics is the only final determinate
Anand.
?Let's make the pictures BIGGER please. The picture on the left shows a little more detail, but I am really being anal here. Both pictures represent a fantabulastic loudspeaker and so, sonics is the only final determinate
Anand.
I don't understand these comments. These are the same picture, one was photoshopped to remove the background and add in a fake shadow (the one on the left) while the one on the right is the original image. They must show the same detail as they are equivalent images. The only thing the one on the left does is make those details more apparent as it removes the distractions of the background.
Depending on the purpose of the image, I too sometimes prefer an image in the natural background. This isn't one of those situation, and for the basic website images, they should probably be photoshoped like markus has done. However, I'd also like to see an "action shot" at some point, with the speakers staged in a theater or room.
Also, Dr. Geddes, are the scales and resolutions of the polar plots all the same? It looks like the resposne of the 10" model is the best of all of them if you were to go by response smoothness/eveness. However, I'm guessing that is just due to a different scale and/or resolution?
Also, why is it that the Abbey has the biggest on axis dip? I would have thought that the dip would become larger as the waveguide got smaller. When I bought the Abbey it was because I had hoped that this model would be the closest thing I could get to a more compact Summa in performance. I feel like the description and data on the website doesn't fully bare that out, even if it is the case.
Depending on the purpose of the image, I too sometimes prefer an image in the natural background. This isn't one of those situation, and for the basic website images, they should probably be photoshoped like markus has done. However, I'd also like to see an "action shot" at some point, with the speakers staged in a theater or room.
Also, Dr. Geddes, are the scales and resolutions of the polar plots all the same? It looks like the resposne of the 10" model is the best of all of them if you were to go by response smoothness/eveness. However, I'm guessing that is just due to a different scale and/or resolution?
Also, why is it that the Abbey has the biggest on axis dip? I would have thought that the dip would become larger as the waveguide got smaller. When I bought the Abbey it was because I had hoped that this model would be the closest thing I could get to a more compact Summa in performance. I feel like the description and data on the website doesn't fully bare that out, even if it is the case.
I appreciate this response, though I think some of my points were misunderstood. I knew going into this that for more than twice the money I would get a big sound improvement with the Summa, per my discussion with you. However, my comment was directed at the Abbey vs Nathan vs Harper descriptions. I wonder if it might be of benefit to make it more clear to people that as you move up the line you get a performance improvement, and what that improvement is. For instance, with some companies, as you move down the line, the only thing you really lose is bass or max output. In the case of yours, it's more complex than that, right? You have less good directivity control, less peak output, less bass, etc. I imagine the crossover point also move up, which has it's own associated issue's. It's not to say that the smaller models are bad, just that spending more get's more through a lot of different changes. I feel this often isn't true of other loudspeaker brands, and it's not made clear in your descriptions (at least not to me), that this is what happens.
I know you had talked about an elliptical waveguide, is that what you mean about an Abbey improved waveguide? Would these version 2 crossovers, or whatever you end up calling it, be something available to those of us with original Abbey's, or will it be based on the new waveguide?
I'm more than willing to beta test these improvements in a timely fashion if you send me different crossover's you come up with as idea's. I've since moved my setup around so that there is no longer the horrible diffraction causing cabinents and subs infront, so my setup should be far better now at revealing differences. I'd build them myself and cover the cost of the parts myself, all I'd want is the schematics.
Cost's would probably be prohibitive for many, and silly for the rest of us, but would you consider offering just replacement cabinets for the speakers as you improve the waveguides if someone was so inclined? In other words if you began offering an improved waveguide, could we purchase the kits for the cabinets with no drivers or crossover parts?
I know you had talked about an elliptical waveguide, is that what you mean about an Abbey improved waveguide? Would these version 2 crossovers, or whatever you end up calling it, be something available to those of us with original Abbey's, or will it be based on the new waveguide?
I'm more than willing to beta test these improvements in a timely fashion if you send me different crossover's you come up with as idea's. I've since moved my setup around so that there is no longer the horrible diffraction causing cabinents and subs infront, so my setup should be far better now at revealing differences. I'd build them myself and cover the cost of the parts myself, all I'd want is the schematics.
Cost's would probably be prohibitive for many, and silly for the rest of us, but would you consider offering just replacement cabinets for the speakers as you improve the waveguides if someone was so inclined? In other words if you began offering an improved waveguide, could we purchase the kits for the cabinets with no drivers or crossover parts?
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Art vs Reality
Just as an example...
Art
Reality
Now... you probably dont need me to tell you which one I want to look at on my wall and which one I want to see when i walk into my garage.
It's one thing to Photoshop out distracting background objects or shadows but when you start altering every part of the image it doesnt look like something i could view with my own eyes.
Now back to the important stuff. Are there any subs in the field yet ? I would be interested in hearing some feedback from current owners and seeing some more pics of the fit-n-finish on the subs. Thanks Earl.
Daniel.
Just as an example...
Art
Reality
An externally hosted image should be here but it was not working when we last tested it.
Now... you probably dont need me to tell you which one I want to look at on my wall and which one I want to see when i walk into my garage.
It's one thing to Photoshop out distracting background objects or shadows but when you start altering every part of the image it doesnt look like something i could view with my own eyes.
Now back to the important stuff. Are there any subs in the field yet ? I would be interested in hearing some feedback from current owners and seeing some more pics of the fit-n-finish on the subs. Thanks Earl.
Daniel.
I've put money down on a pair of subs, but not received them yet. I'm still awaiting Dr. Geddes to let me know when mine are built and ready. They will each be receiving a solid 300 watts or so from a very robust amplifier I have for them using Aussieamps modules from a little while back and a massively overbuilt power supply.
Once I receive them I can compare them to the various DIY subs I own. I haven't purchased a manufactured subwoofer in a good ten years since making a basic sealed or even ported sub is really one of the easiest DIY projects. I will have a pair of Dayton 12" reference subs in 2 cubic foot sealed boxes, a isobaric push-pull XLS 12" sub, a TC Acoustics 3000 12" ported sub with a 5 cubic foot enclosure tuned to 20hz or so (this is a special version of the 3000 which has a lighter cone and works in larger boxes), and a 7" Mpyre Audio Bandpass I came up with using multiples of the mpyres I have from when the company went out of business. I should be able to get a pretty good comparison of Dr. Geddes sub as compared with a variety of different types and designs.
Once I receive them I can compare them to the various DIY subs I own. I haven't purchased a manufactured subwoofer in a good ten years since making a basic sealed or even ported sub is really one of the easiest DIY projects. I will have a pair of Dayton 12" reference subs in 2 cubic foot sealed boxes, a isobaric push-pull XLS 12" sub, a TC Acoustics 3000 12" ported sub with a 5 cubic foot enclosure tuned to 20hz or so (this is a special version of the 3000 which has a lighter cone and works in larger boxes), and a 7" Mpyre Audio Bandpass I came up with using multiples of the mpyres I have from when the company went out of business. I should be able to get a pretty good comparison of Dr. Geddes sub as compared with a variety of different types and designs.
Matt
Yes, you have it quite right and makes some very good points. When I was at Ford one time we had marketing looking for a "good" way to distinguish in simple technical terms the differences between HI-end system and the lower end ones. They were quite disappointed that the "simple" answers did not show much difference. They actually discussed lowering the quality of the low end to make the "hi-end" look better. The whole comparison in a product line is dangerous for all the reasons that you state. It just does not seem like there is as much difference as the costs would justify. I mean, for the money, the Harpers are the "best buy" - no doubt about it. It takes a lot of money to get an incremental performance improvement.
I would always let a customer have a new crossover schematic so that they can upgrade it. But they have to bear the costs themselves. The Abbey is a second order LP and the Summa is a third. This seems to give a much better response at the crossover. But this is not a small cost increase since I have to add another one of the single most expensive crossover component - the large woofer inductor. And there are other parts required as well. I'm going to try this when I get a chance to see if it is worth the extra cost.
I'm not sure what would be workable as far as upgrading goes. I know that at some point I will either offer an elliptical or the 15" waveguide as it simple does work better. But I need to get my current production under control before I can even think about new products. I am way in the hole at the moment.
There are some that have gone out, but nothing that the customer is willing to report (some people just don;t get into the online posting thing). "Fit-n-finish" wise things are getting better all the time. It's been a long road, but I am now comfortable that I can make a good cabinet. I know that I can do a better job than 80-90% of the people who build the kits themselves. I can't do a "Wilson" grade enclosure YET, but I don;t charge those prices either. I am considering using some exotic cabinet materials for the simple reason that wood just does not lend itself to precision and stable substrates for paint. Thats why I gave up on MDF and why I may even give up on plywood. I would love to make a cabinet out of polyurethane boards since that stuff would be ideal. But it is outrageously expensive. About 6 times a good plywood.
I built an array of eight subs to go with my Summas. Five are sealed, two are bandpass, and one is a tapped horn.
I found that the sealed subs were noticeably "grungey" compared to the Summas, and I abandoned the project after a couple months.
Anyone want a good deal on some Audax woofers?
Anyways, it's takes a very clean sub to keep up with the Summas. The only sealed box that was tolerable used a set of TC Sounds fifteens. Distortion from my bandpass and tapped horn subs wasn't as offensive, likely due to the distortion filtering mechanisms in those boxes.
Anyways, these speakers tend to "reset" your expectations of subwoofer performance. And even the big ol' Summas need subs.
HTH
I think that I must have avoided that one because its hard to say. The devils in the details as they say. What I have found best is to avoid ANY local "discontinuities". That means that a flush mount of the speakers away from corners or wall features would probably be great, but anything that doesn't fit that model would be in that grey area known as "degrees" of "not right" and thats a very grey area.
Hey John
I'm almost ready to disclose my new ideas in testing subs. I kept thinking that there had to be some way to get something meaningful. To me, frequency response of a sub is pretty much irrelavent. Once in the room its response changes and then when I EQ it it changes again. By the time I'm done there is no relationship between the FR that I started with and what it is now. What matters is: can the sub handle all this manipulation, because if it can't then I'm sunk.
So what I need to know is when does it "fart". Thats what I call it because, and the test bears this out, what usually happens is the sub is fine then all of a sudden its crap! And then it sounds like its farting. I have to know when this happens.
I do a sweep from about 10 Hz to 200 Hz and plot the spectrum in a spectrograph. I do this starting at 94 dB nearfield and raise the signal 3 dB each sweep. At some point, sure enough, every sub goes to hell. BUT, this happens at a huge variation in output levels. Sometimes - most often - when there is a plate amp it clips before the speaker shows much problems. This tends to happen at a very low SPL level. When I ran my subs with an external amp I got almost 16 dB more OBF (Output Before Fart).
I was able to show that my first design had some port turbulence issues since this was apparent before the speaker or amp had problems. Its really a very revealing test and easy to do. You have to be very careful about clpping the mic in nearfield as I chased a problem that wasn;t even in the speaker for a while before I realized what was happening.
"In general" yes. How far is another issue. I mean you usually can't put them that far from the walls. Mine are about two feet from the walls to the sides of the speaker. Its mostly the "clutter" arround the speakers that I worry about. All the little sharp edges that cause diffraction. Its all very hard to quantify, but I have found that the clearer the area arround the speakers is from "stuff" the better.
So can I take it that the hot chicks on your web site don't actually work there? I mean its rare to find three girls that look that good in one city let alone in one office.
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What does the spectrograph look like when the sub begins to "go to hell"? Presumably there is something you can measure that shows up before the audible effects.
- Doug
Different problems show up differently, which is how you can tell what the problem is. Clipping is a strong upward spread in signal content to very high orders, but clearly in strips as harmonics. Turbulence is a broad non-harmonic smear in the signal that goes high and low in frequency. If the driver is straining then the harmonics spread out but more gradually than clipping, more like turbulence, but as lines meaning they are harmonic.
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