Ray Collins said:
I don't quite understand what you mean. In my HT I use three identical units across the front. The outside two are toed in. The center one is straight ahead.
If you mean that you need to lay it on its side to place it under the screen, well thats not a good solution. The center channel is critically important in film, its most of the sound and virtually ALL of the dialog. It needs to be behind the screen. Don't use a screen? You should, its the only way to get the sound right. Make the screen out of a bed sheet and its perfectly acoustically transparent.
From my experiments I'd rather use a phantom center than use a higher or lower speaker placed on its side. Phantom works OK, speakers below the screen don't - neither do ones above the screen. The image just isn't right. Thats not the way the film was mixed.
gedlee,
Thanks but I am using a plasma and do not have a choice regarding center orientation--it must be placed on its side beneath the screen. Since 80% of the sound is distributed through the center, I think the lesser compromise is to have it slightly displaced rather than not having a center. A required compromise and forced choice. Oh well...
Ray
Thanks but I am using a plasma and do not have a choice regarding center orientation--it must be placed on its side beneath the screen. Since 80% of the sound is distributed through the center, I think the lesser compromise is to have it slightly displaced rather than not having a center. A required compromise and forced choice. Oh well...
Ray
I kindly disagree.
IMO, you are better off having NO center channel and sending that information to the LR's than fruitlessly spending money on a speaker that will be oriented incorrectly. This causes detrimental lobing effects, comb filtering, and frequency response anomalies that have nothing to do with the Speaker Dr Geddes has engineered.
It is (one of) the greatest pieces of misinformation that marketing people have provided to the public at large that laying an MTM loudspeaker is OK. Center channels are "supposed" to widen the sweet spot and listening area over a wider space. Laying a speaker on it's side that was not designed for it actually hinders this concept.
Please, save your money and your ears.
Chris
IMO, you are better off having NO center channel and sending that information to the LR's than fruitlessly spending money on a speaker that will be oriented incorrectly. This causes detrimental lobing effects, comb filtering, and frequency response anomalies that have nothing to do with the Speaker Dr Geddes has engineered.
It is (one of) the greatest pieces of misinformation that marketing people have provided to the public at large that laying an MTM loudspeaker is OK. Center channels are "supposed" to widen the sweet spot and listening area over a wider space. Laying a speaker on it's side that was not designed for it actually hinders this concept.
Please, save your money and your ears.
Chris
chrismercurio,
I appreciate your interest but I did not say that I was going to lay an MTM speaker on its side and use it as a center channel....even if I did I doubt that it would hurt my ears. The height of the center speaker baffle would be limited to 13" I my particular application and as wide as the designer felt feasable. As for money, that is not a factor.
gedlee,
Thanks for the response. If I go without a center I will probably use four of your kits. What is your time frame on orders?
Ray
I appreciate your interest but I did not say that I was going to lay an MTM speaker on its side and use it as a center channel....even if I did I doubt that it would hurt my ears. The height of the center speaker baffle would be limited to 13" I my particular application and as wide as the designer felt feasable. As for money, that is not a factor.
gedlee,
Thanks for the response. If I go without a center I will probably use four of your kits. What is your time frame on orders?
Ray
chrismercurio said:
Chris
I whole heartedly agree and I have done these studies myself. A phantom channel works pretty good if you have GOOD left and right mains, but speakers on the floor (or high up) or turned on their side is a bad idea. The typical center channel as sold at the stores is a total waste of money that only degrades the sound. I have told this to so many people!! But they go to the stores and some salesman tells them otherwise - AND THEY BELIEVE THE SALESMAN!!
I have a plasma and I have a projector - there is no contest which is better - its not the plasma (or LCD). For watching a film the projector is far better. For TV they are about the same. TV is adjusted for this kind of display, but film is done for projection.
I'm in line for one of your waveguide kits. Since I live in Norway, I plan to buy the waveguides/baffles only, and source drivers here in Europe.
As I understand it, the full kit is for a 10" waveguide and a 10" speaker (you have mentioned the B&C 10ps26).
My question: will I compromise the design if I used a 12" speaker instead of the 10-inch? Does the different polar response on the 12" matter - compared to the 10-inch?
(I construct my own crossovers, and have OK measuring facilities).
Thanks, Espen
As I understand it, the full kit is for a 10" waveguide and a 10" speaker (you have mentioned the B&C 10ps26).
My question: will I compromise the design if I used a 12" speaker instead of the 10-inch? Does the different polar response on the 12" matter - compared to the 10-inch?
(I construct my own crossovers, and have OK measuring facilities).
Thanks, Espen
EspenE said:
In my opinion you will compromise the design if you do your own crossover. Thus, if you insist on doing that it makes no difference what woofer you use.
My waveguides are simply not that easy to do crossovers for and I use techniques that are beyond even capable DIY's. Its all custom software that I have assembled over decades and a lot of experience.
I would NOT suggest changing my design. Build it as specified.
Earl,
This last post about crossover construction is why I earlier suggested that you only offer completed crossovers with your kits. People subsequently listening to completed kits cannot tell that the heart of the design-the crossover-has been modified from the original, and for better or worse will believe it to be your work. A poorly done modification will only have negative effects on the public perception of your work.
LAL
This last post about crossover construction is why I earlier suggested that you only offer completed crossovers with your kits. People subsequently listening to completed kits cannot tell that the heart of the design-the crossover-has been modified from the original, and for better or worse will believe it to be your work. A poorly done modification will only have negative effects on the public perception of your work.
LAL
LAL said:
In a sense, I agree on that. I'm sure that Earl's crossover and the chosen units is the best for his design. No disagreement on that. And I intend to build it just as specified.
But as an experienced and interested (and, I hope: competent) DIY'er, I would be inclined to experiment with the crossover and drivers anyway - if only to satisfy my own curiosity about the waveguide principle. I have played around with 2-way horn constructions a long time, and - appearently like many others - am intrugued by a design that has been a major theme on many DIY-forums for a long time.
I have a lot of units lying about. I will certainly try the waveguides and play around with a number of drivers and bass units.
Earl: my question was not so much about the crossover network itself, as it was about matching the polar response of various size bass units to the polar response to the waveguide. How critical is woofer size compared to the acutal 10-inch waveguide size?
LAL said:
Understood, but wiring the crossover is one of the most time consuming parts and my doing it would drive up the price substantially. I just don't see it as an option.
EspenE said:
The waveguide size has more to do with how well it works than the crossover point. A 10" one does not control as well as the 12" which is not as good as the 15". Ideally it should be about 18" - I could make that size work perfectly. The 10" has a lot of flaws, but the size is attractive to most people.
The woofer size determines the frequency at which the two source patterns mate up. As you would expect the 10" woofer mates to the 90° output of the waveguide at a higher frequency than the 12" and 15". The 15" is about 800-900 Hz the 12 about 1 kHz and the 10 about 1500 Hz.
From my data, the ideal would be an 18" waveguide with a 12" woofer. This would elliminate all the flaws that I see in practice. But such a combination would not be an attactive speaker for a lot of reasons. the next best, and what I would build for myself, is a 12" woofer and a 15" waveguide. Simulations indicate this combination to be a very good match.
salas said:
Everything always comes back to the "marketing". I've decided to try making small kits and see how that works. If it doesn't, then I doubt that I will do anything else.
As cost goes up you sell less, as size goes up you sell less, if low cost small size does not sell then where's the market?
gedlee said:
The market is set by the pro network decades ago. You look for niche markets. Some kit here, a custom installation there even with some expensive one off speakers. Find small installers that they need to boast quality and difference, and can import your speakers starting a small trend in up coming markets like Russia etc.
Visit Pro light and sound next spring with your speakers and papers and nice brochures, and talk to people there. Some installers in Europe have customers in Classical and Jazz music that look for excellence and new things...
In Thailand they just need beautiful ladies around the pole, not quality sound. Dirty SPL and a known badge on the plastic box is ok when the farangs use their eyes and not their ears.
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