Hi I have been building and experimenting with various configurations of a two way speaker. I also tested various three way designs and found that I prefer the sonic response and simplicity of a two way speaker to a three way for my home listening purposes at midfield distance and volume. The speaker I have settled on for now is a single 15 inch woofer crossed at 700hz and a 1.4 inch compression driver mounted to a wave guide. I would like to expand the low frequency section to either two 15 inch woofers or four 12 inch woofers. Is there an advantage to the four 12s over the two 15s with regards to bass and mid frequency response given the 700hz crossover point? Thanks.
Jay
Jay
If you go with 12", how are you going to place them? MTM? Or 2.5 way, TMM? Spacing?
It seems to me that since you are happy with mids and highs, only need low end extension, add a sub or two.
It seems to me that since you are happy with mids and highs, only need low end extension, add a sub or two.
OR a different 15. Going to multiple 15s is going to be hard to integrate for a two way 700hz design.
TMM horizontal for the two woofers. I like the cleanness and lack of room resonances achieved by not incorporating a subwoofer at this point. The is still ample bass in the current configuration. As soon as resonances are introduced -- standing waves -- the listening experience is substantially lesser. That I plan to experiment with subwoofers as the next project after sorting this out and I already have drivers and a design lined up for that.
Why is multiple 15s going to be hard to integrate?
Why is multiple 15s going to be hard to integrate?
Because ideally you want the centre to centre distances between woofers / horn to be ~1/4 wavelength (or less) at crossover.
I'd suggest a 2.5 way as has already been suggested, crossed low enough that the 2nd woofer is not going to cause problems at the xo point.
JBL did this with the Everest DD67000, well worth looking up the manuals / graphs / specs for inspiration.
Rob
You are wanting to create an array of woofers which will be acoustically large, and potentially not round anymore.
What are the issues that you observe. I see this configuration as advantageous in that the wave guide in a horizontal TMM configuration as being more isolated than a MTM configuration which should yield a clearer sonic image from the compression driver and waveguide combination.
I'm really old fashioned so I use this calculator . I enter the xo frequency and then divide the length by 4 for the 1/4WL figure.
According to the 1/4wl rule the centre of your 15" driver should be approx 4.8" from the centre of your horn.
According to Geddes the vertical spacing does not matter (his Summas have a vertical gap of around 15") but horizontal is important.
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Since our ancestors lived on planes of africa, hunting or being hunted, pinpoint identification where the sound is comming from on the horizontal plane was of utmost importance.
That's why we have ears located horizontally, for stereo. Similarly eyes too.
Multiway speakers placed horizontally is the worst placement, big no no, because each speaker will be recognized as separate source, as long as frequency is higher than 150Hz. Below that, our ears are too close. For stereo bass we would need to look like hammerhead.
That's why all multiway speakers are arranged vertically.
Because it will still sound as one pointsource, more or less. Because we are less sensitive in vertical plane. We can tollerate some speaker lobing in mtm in vertical plane, because our ears are horizontally oriented, hence sensitive for horizontal placement.
Unless you listen lying on the couch.
That's why we have ears located horizontally, for stereo. Similarly eyes too.
Multiway speakers placed horizontally is the worst placement, big no no, because each speaker will be recognized as separate source, as long as frequency is higher than 150Hz. Below that, our ears are too close. For stereo bass we would need to look like hammerhead.
That's why all multiway speakers are arranged vertically.
Because it will still sound as one pointsource, more or less. Because we are less sensitive in vertical plane. We can tollerate some speaker lobing in mtm in vertical plane, because our ears are horizontally oriented, hence sensitive for horizontal placement.
Unless you listen lying on the couch.
I am very much surprised you find 3way sound worse than 2way. Its usually other way arround. Are you sure you made that 3way right?
There is a dozen of reasons 3way will sound better than 2way. I personally consider even 3way compromise, most of my speakers are 4way. But this is of topic. So i am out.
Good luck with horizontal tmm 2way.
There is a dozen of reasons 3way will sound better than 2way. I personally consider even 3way compromise, most of my speakers are 4way. But this is of topic. So i am out.
Good luck with horizontal tmm 2way.
I am lying on the couch though I will experiment with horizontal and vertical configurations because why not.
I prefer the point source nature of a two way. I find the mids sound quicker and more detailed when overtones are rendered from the same driver. In the case of my build the two way the Beyma CP755ND is physically superior to any of the midrange compression drivers which I was testing. I intend to test some ten inch cone woofers in a three way at some point.
I prefer simplicity and minimalism which correlates to my philosophies related to ecology and reducing material consumption. I prefer to operate within these constraints with anything I am designing or making. I find speakers like the Wilson Audio Chronosonic grotesque -- they are the visual equivalent of listening to a tone deaf Sammy Hagar shriek into a digitally distorted microphone. Where as a speaker like the TAD 2401 is a very elegant, elemental, and logical design in my opinion. I figure if a decent full range driver can play music fairly admirably, a speaker comprised of a 15 inch woofer and a compression driver that extends to 20khz by virtue of a strong motor, advanced diaphragm, and proper phase plug design, should be sufficient for all home listening applications. Anything beyond that is a complication that exists to overcome constraints that are presented when designing for high output applications. Speaker design has nothing to do with optimizing the vocal range in my opinion, which is not 100hz-900hz but more like 100hz-10000hz.
I prefer the point source nature of a two way. I find the mids sound quicker and more detailed when overtones are rendered from the same driver. In the case of my build the two way the Beyma CP755ND is physically superior to any of the midrange compression drivers which I was testing. I intend to test some ten inch cone woofers in a three way at some point.
I prefer simplicity and minimalism which correlates to my philosophies related to ecology and reducing material consumption. I prefer to operate within these constraints with anything I am designing or making. I find speakers like the Wilson Audio Chronosonic grotesque -- they are the visual equivalent of listening to a tone deaf Sammy Hagar shriek into a digitally distorted microphone. Where as a speaker like the TAD 2401 is a very elegant, elemental, and logical design in my opinion. I figure if a decent full range driver can play music fairly admirably, a speaker comprised of a 15 inch woofer and a compression driver that extends to 20khz by virtue of a strong motor, advanced diaphragm, and proper phase plug design, should be sufficient for all home listening applications. Anything beyond that is a complication that exists to overcome constraints that are presented when designing for high output applications. Speaker design has nothing to do with optimizing the vocal range in my opinion, which is not 100hz-900hz but more like 100hz-10000hz.
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I agree with this.
I don't draw the conclusion that it's because they are close together. 1/4 wavelength spacing is one way to handle the issue, but it isn't the problem.
In that case I would bin the 15's and buy the new set of 8x 12's you were contemplating.
What does this even mean as it pertains to my point about overtones? Handling what issue?
Haha I hear you I am curious in the name of science and the progress of our great nation, and a hypocrite at times. Sue me.
Why do you feel that overtones are reproduced better when from the same driver? Why a point source?
It's sort of a logical assumption thing that correlates to my preference when listening to different speaker configurations -- a plucked string is not an isolated sine wave but an amalgam of overtones determined by the finger position, material of the string, design and material of the resonating body, etc. Add electric amplification and now you have even more added overtones from pickups, transformers, tubes, etc. It is logical to me that this complex waveform, which is still in essence a single note, will be rendered more accurately from a single driver point source, than a grouping of non concentrically oriented drivers. This pertains to how musical passages are rendered in general in my opinion and my assumption matches my perception.
A line source is great especially in an arena where the goal is to project time aligned sound at equal output over a variable distance and at a variable angle relative to the listener distance. In a normal midfield size listening space where the listener is moving around there is advantages to a line source too. I do my listening sitting in a single position and thus I do not need the benefits of a line source. In addition my speakers feature good dispersion and fill the listening space with sound and thus there is no roll of frequencies due to the point source nature of the speakers that I would deem a perceptible issue. Also point source speakers make more sense to me from an imaging stand point -- in that I find they render the placement of music in space in a very convincing manner. Home size line sources, electrostatic panels, and ribbon panels are too grand in a way that I find distracting and un-intimate. Quad 57s are an exception. I intend to build some line source electrostatics to test against my more point source type speakers to explore this observation again in a direct comparison.
A line source is great especially in an arena where the goal is to project time aligned sound at equal output over a variable distance and at a variable angle relative to the listener distance. In a normal midfield size listening space where the listener is moving around there is advantages to a line source too. I do my listening sitting in a single position and thus I do not need the benefits of a line source. In addition my speakers feature good dispersion and fill the listening space with sound and thus there is no roll of frequencies due to the point source nature of the speakers that I would deem a perceptible issue. Also point source speakers make more sense to me from an imaging stand point -- in that I find they render the placement of music in space in a very convincing manner. Home size line sources, electrostatic panels, and ribbon panels are too grand in a way that I find distracting and un-intimate. Quad 57s are an exception. I intend to build some line source electrostatics to test against my more point source type speakers to explore this observation again in a direct comparison.
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I agree.
Some say it's good if the signal comes to your listening position in the right balance, and the sound spreads from the speaker cleanly, and goes into the room in a good way and remains balanced.
One way to achieve this involves fewer, closely spaced drivers.. some say it can also be achieved if the speakers are more than a wavelength apart.
A driver is going to become less of a point source as the cone nears and exceeds 1 wavelength, or goes into breakup, or the cabinet diffracts. I wonder if this adds to the point, or am I missing the point?