Home Theater Forum and Systems banner

21 - 31 of 31 Posts

·
Registered
Joined
·
969 Posts
I personally like my Klipsch Reference speakers avaserfi. Klipsch has always advocated horn loading. I do like the sound of B&W and Paradigm speakers though and they're not (or at least most of them aren't) horn loaded.

Am I wrong in thinking that a basic dome tweeter is pretty much the same as a basic horn loaded design minus the horn? You can horn load any driver for that matter (ie: the Klipschorn or La Scala). Is the main goal of a horn to increase the sensitivity of the speaker without distorting the output too much?

As for sweet spot, would that not depend on the construction of either horn or tweeter. If you look at the aluminum dome tweeters on some Paradigm speakers (ie: the Signature series) they have a unique wave guide. I'm sure this sort of design would affect the direction of the frequencies emitted by the tweeter to enlarge the sweet spot and control any erratically dispersed waves.

Correct me if I'm way off in my assumptions.
 

·
Banned
Joined
·
1,131 Posts
Am I wrong in thinking that a basic dome tweeter is pretty much the same as a basic horn loaded design minus the horn? You can horn load any driver for that matter (ie: the Klipschorn or La Scala). Is the main goal of a horn to increase the sensitivity of the speaker without distorting the output too much?
Theoretically any driver could be horn loaded, but ideally you would want to use one that was designed for the specific application just as with any driver. Also, there are certain trade offs for this increased sensitivity, i.e., poor off-axis frequency response a common trait in most horn loaded designs.

Personally, I would never make the efficiency trade off in regards to high fidelity mid/far field listening. The cost for increased sensitivity just isn't worth the worsened off-axis response unless one needs a PA system in which fidelity isn't the primary concern. After all, proper amplification coupled with a well designed driver will allow for required SPLs in with inaudible compression and distortion assuming typical listening habits and even if the music that has extreme transient peaks of 110-115dB.

As for sweet spot, would that not depend on the construction of either horn or tweeter. If you look at the aluminum dome tweeters on some Paradigm speakers (ie: the Signature series) they have a unique wave guide. I'm sure this sort of design would affect the direction of the frequencies emitted by the tweeter to enlarge the sweet spot and control any erratically dispersed waves.
I refer you to this post as it should cover the question posed fully. Focus on the last section.
 

·
Registered
Joined
·
316 Posts
Nonsense. Cone behavior depends fundamentally on cone design. There's no reason one shouldn't expect an 8" woofer to be just fine with a ~1.6kHz Fc, assuming it's coupled to a tweeter that matches its directivity at that frequency. Without a CD tweeter, of course, such a system would be hopeless.
Using an 8" unit up to that point(1.6khz example) will result in poor off axis response. It is NOT an option to use a waveguide that limits the tweeter to such an extent. It is non-ideal compared to a system that can keep a more even dispersion characteristic off axis, according to the perceptual research by Paisley, and by Toole.


All of them have some drawbacks. Three-ways more often than not sound incoherent, t
If you want to classify 'most' speakers, then 'most' speakers, regardless of design, are rubbish IMO, for ideal sound reproduction quality. I have extremely high standards and requirements in many different measured areas, and most speakers regardless of price, do not come close to meeting these standards I have set(which are based strictly on the standing perceptual research). It is not easy by any stretch of the imagination to design a system that meets all of these standards(one of which includes ideal mirrored off axis response up to a minimum of +/- 60 degrees, across the entire audible bandwidth relevant for music reproduction). I can make compromises for special purpose speakers. For example, a music production studio generally has early reflections that are either highly dampened or simply not reflecting back to the listening position, and generally in mid or near-field placement. Off axis response is not important in such an environment - there for I will waive my requirements for the off axis response standards in this case. For example: B&W 802D makes a superb monopole studio monitor in these conditions. It is very linear, has superbly low resonance drivers and a nearly inert cabinet system for minimum timbre distortion. But that speaker does not have an off axis response that meets my standards for a room that (ideally) uses the horizontal reflection points to increase perceived sound quality. But please note that my preference is for omnipolar, or near-omnipolar dispersion. As far as monopoles, the 802D is a superb speaker for all intents and purposes.

-Chris
 

·
Banned
Joined
·
22,577 Posts
You seem to keep mentioning Toole. Note what his speakers, which I consider some of the best currently available at their given price points, are doing to control tweeter directivity at the bottom of their respective passbands!
What speakers does he own?
 

·
Registered
Joined
·
316 Posts
Philosophical difference, I guess. I see no need for a 120deg pattern. Quite the contrary, in fact. I side more with Geddes and Danley in having found that in the typical domestic living room a much narrower coverage area is desirable, because you get direct radiation at the listening position and less reflected sound. As I see it, "reflections" should come from the side and/or rear channels, not be spewed haphazardly about the room by the mains. The smaller the room, the narrower I would try to go, down to an arbitrary minimum of maybe 45deg or so.
But as Toole and other credible researchers have found, when the 1st horizontal reflections are very similar to the on axis sound, this reflected sound enhances perceived sound quality, when it is within a suitable time delay window. Read Toole's 'Loudspeakers and Rooms for Sound Reproduction: A Scientific Review', published in the JAES in 2006. It is a summary work going over the various modern research and conclusions based on such.


The other approach with significant theoretical and listening test support, which I take is your approach even though you've not talked much about the second prong of it, is to go wider with lots more room treatment.
It is true that to optimize the potential for a very wide response, certain additional treatments are needed. For example, cross channel talk should be minimized, also specified in such research. Due to the wide radiation pattern of an omnipolar, ideally, a middle room front dividing absorber would be used. Not by any chance desirable for cosmetics. I use such a device and it works as expected. Other than this, and lack of treatments at the 1st reflection points, the acoustical treatment is similar to any other application.

Alas, most room treatments that work are ugly, so attacking the problem from the speakers rather than the room makes more intuitive sense to me.
I am a function over form person. I will deal with the specific 'ugly' treatment method in order to achieve higher potential sound quality.




I seriously doubt that unit would measure up to my requirements, in regards to several parameters.


Well, Toole does not actually design speakers. His research is used towards improving speakers for his former employer, Harman. There is also more than one reason to use shallow waveguide tweeters. One major benefit, especially for a speaker manufacturer, is to make the tweeter immune to the baffle edge diffraction. While normally, a baffle would require large radiuses(in the 2" range minimum for ideal behaviour) to prevent baffle diffraction transfer function errors, which can be costly to use in production, a shallow waveguide makes the cabinet edge irrelevant for the tweeter and is a low cost solution. My computer speaker monitor system uses tweeters with shallow waveguides for this very reason.

-Chris
 

·
HTS Senior Moderator
Joined
·
5,423 Posts
Don't cha just love a good discussion that can stay on topic, does not stoop to name calling and personal attacks? :clap: :T :clap:

Keep going, I for one, find this very interesting.
 

·
Banned
Joined
·
22,577 Posts
I applaud you guys as well. :clap:

This is how we can really learn things and how civil discussions should be. This is an absolutely wonderful example thread.
 

·
Banned
Joined
·
1,131 Posts
Right. Thing is, a good CD design (separate waveguide or coax) tends to do that better than flush-mounted drivers...
Do you have measurements backing up this statement? Waveguides are designed to limit wide dispersion and from what I have seen tend to roll off off-axis frequency significantly.

Please note that quality off-axis frequency response being referred to by Chris and I would be around -5dB or so taken at 60 degrees at 15kHz.

It occurs to me from reading your description of room treatments that we're talking about entirely different applications. You're a strictly 2-channel (or 2.1), aren't you? I don't do 2-channel any more. I find that a center channel (even using plain DPL2) immensely enhances realism and my appreciation for recorded sounds generally. Even my nearfield system is 3.1 channel (8" Tannoy duals, JBL W15GTi). In my old flat it was 5.1, but my current office configuration does not make surrounds possible.
Correct, 2-channel audio is being discussed. Exactly how does the addition of a third channel increase your perceived realism? I am interested to see your impressions on this as this could be caused by the poor off-axis response of speakers with high directivity and their interaction with the room.

I question that only because the controlled directivity/fairly live room approach seems to yield very similar results to the omni/treated-to-death approach, but is much less aesthetically intrusive. If you haven't tried a good controlled directivity design, I'd recommend looking into it.
I have not seen any perceptual research that support this statement. Also, I have seen few to none omni-polar systems set up properly in terms of placement and room treatments.

Why? The axial response is flat enough, and the polar graphs are superb.
I would be interested in seeing credible 3rd party measurements to verify this.

Seems like this time I am just asking for links :nerd:.
 

·
Registered
Joined
·
316 Posts
It occurs to me from reading your description of room treatments that we're talking about entirely different applications. You're a strictly 2-channel (or 2.1), aren't you? I don't do 2-channel any more. I find that a center channel (even using plain DPL2) immensely enhances realism and my appreciation for recorded sounds generally. Even my nearfield system is 3.1 channel (8" Tannoy duals, JBL W15GTi). In my old flat it was 5.1, but my current office configuration does not make surrounds possible.
I don't do multichannel as of yet due to lack of standards to produce true realistic reproduction. But as for subjective claims, I have no intention of making such statements in this thread, if you expected such.



I question that only because the controlled directivity/fairly live room approach seems to yield very similar results to the omni/treated-to-death approach, but is much less aesthetically intrusive. If you haven't tried a good controlled directivity design, I'd recommend looking into it.
One would not yield a similar result with a wide even dispersion system unless one treated the 1st reflection points with absorbers, which I certainly would not. Go back and refer to the treatment approach I described. The 1st wall reflections are a critical part of the sound quality, in regards to maximizing timbre resolution of recorded material and enhancing spatial properties. This method is based on properties found by Toole, Olive, Ando and other perceptual researchers that increase perceived sound quality.



Why? The axial response is flat enough, and the polar graphs are superb.
Super to who's standard? I consider it useless for my purpose(which is maximized realism and timbre resolution). In addition, I don't expect much from this in regards to cabinet resonance properties or even in regards to driver resonances.

True, but the thing is, controlling edge diffraction is part of controlling directivity. So it's really just the flip side of the coin.
You have that backwards. In your use, controlling directivity avoids diffraction by never encountering the baffle edges. But a design with a proper curved baffle has no such problem with diffraction, and in addition, can have very wide dispersion.

-Chris
 

·
Banned
Joined
·
22,577 Posts
What speakers does he own?
No idea, honestly. I've never met the gentleman.
But you wrote:

Note what his speakers, which I consider some of the best currently available at their given price points,

Now you really have be wondering... how do you consider them some of the best currently available at their given price points if you don't know what he owns. :scratch:

:whistling:
 

·
Registered
Joined
·
1 Posts
But you wrote:

Note what his speakers, which I consider some of the best currently available at their given price points,

Now you really have be wondering... how do you consider them some of the best currently available at their given price points if you don't know what he owns. :scratch:

:whistling:
I was under the impression that he was making reference toward speakers that had benefited greatly from the adaptation/implementation or "[usage]" of Toole's research, Toole's former employer, Harman.:huh:

But what do I know, this is my first post and the first thread I've read top to bottom on this thread. Wonderful job gents, I've had a great time lurking. I still wish some of it wasn't over my head.:blink:

Aaron

P.S. Thanks Sonnie, for making the Shack a reality.
 
21 - 31 of 31 Posts
Top