Horn tweeters V.S. aluminum dome tweeters - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com

Reply
 
Thread Tools
post #11 of 31 Old 01-30-08, 01:43 AM
Elite Shackster
 
Sonnie's Avatar
 
Join Date: Apr 2006
Location: L.A. (Lower Alabama)
Posts: 22,577
My System
Re: Horn tweeters V.S. aluminum dome tweeters

I plan to get a pair of bookshelf speakers with a center for our great room, so this thread may help me decide what to get. I had looked at the Klipsch and the JBLs... particularly the RB-51 and L830.




Bob... if this discussion is not helping you and you feel I'm hi-jacking your thread, let me know and we'll move it. I'm hoping that it's helpful to you though... and others as well.
Sonnie is offline  
Sponsored Links
Advertisement
 
post #12 of 31 Old 01-30-08, 08:04 AM
 
Join Date: Jul 2007
Posts: 1,131
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
DS-21 wrote: View Post
I've never heard a system with a flush-mounted tweeter that had a consistent sound on- and off- axis. All of them seem to get in trouble at the crossover region. Sure, there are some band-aids (e.g. the BBC dip) but to my ears they don't work as well as just doing it right to begin with.
This statement actually surprises me coming from you due to the extreme objectivity you have shown in other threads. Nonetheless subjectivity is important so...

This lack of consistent sound is likely due to the poor integration. Using a digital crossover along with matching axial and off-axis response you can achieve this consistent sound.

Using something like the Infinity 10PR80BZQ-FW02 4" mid range coupled with a tweeter such as the Neo PDR3 this response can be achieved. The Infinities off axis response at 60 degrees is nearly identical to the axial response up to 3000kHz. The PDR3 has an extremely linear response from around 2kHz to 20kHz with its off-axis response 60 degrees at 15kHz being only -5dB if flush mounted with proper baffle compensation. A combination such as this will allow for complete continuity with proper crossover use as the axial responses are nearly identical.

The real issue with such mounting is the typical DIYer and speaker manufacturer do not invest the time in testing/designing drivers until they are ideal for a given application which is why inconsistency occurs. I will say it can be much harder to achieve proper response using a flush mounted non-waveguide tweeter, but once implemented properly the results are far superior in both an objective and subjective* sense as off-axis dispersion is allowed to flourish in a way not conducive to the waveguided design.

*Both Ian Paisely of Mirage and Floyd Toole of Harman through various double blind tests of thousands of participants found wide off-axis dispersion with similar magnitude to on-axis is preferable.

One thing that I have noticed about these typical horn loaded designs is that their off-axis tweeter response is lacking in said linearity which has been shown to be preferable by the credible perceptual research. This is why I recommend them for highly reverberant rooms as the imaging would be better in such a case or for a near field application, but when compared with a loudspeaker that has a wider, more linear, dispersion pattern (all else being equal) in a acoustically treated environment subjective reviews will fall with the latter discussed loudspeaker.

As far as the discussion that there are only a handful brands putting out speakers worth buying that is simply ludicrous.For example B&W and Ascend Acoustics both quite a few speakers that perform well in the objective sense as laid out by perceptual research as well as the subjective sense. Furthermore, another Harman subsidiary that was never mentioned, Infinity has developed some speakers that are simply superb especially considering their price point. One such example is the Primus 360 (do not confuse this with the Primus 362). The perceptual research conducted does show issues with some designs, but more importantly, if fully understood, gives on an objective method of rating loudspeakers via measurements in the end design methodology should be ignored as it is not necessarily indicative of quality.

For those interested this link has all of Harman's child companies.

Quote:
Sonnie wrote: View Post
I plan to get a pair of bookshelf speakers with a center for our great room, so this thread may help me decide what to get. I had looked at the Klipsch and the JBLs... particularly the RB-51 and L830.




Bob... if this discussion is not helping you and you feel I'm hi-jacking your thread, let me know and we'll move it. I'm hoping that it's helpful to you though... and others as well.
Sonnie, if you tell me your budget for the two speakers I will make a suggestion as the best speaker in the price range tonight. There are far more issues in speaker design than just tweeter directivity that have been shown to increase or decrease listener ratings.

Last edited by avaserfi; 01-30-08 at 08:23 AM.
avaserfi is offline  
post #13 of 31 Old 01-30-08, 10:23 AM
Elite Shackster
 
Sonnie's Avatar
 
Join Date: Apr 2006
Location: L.A. (Lower Alabama)
Posts: 22,577
My System
Re: Horn tweeters V.S. aluminum dome tweeters

I'll start a new thread for those bookshelves and toss my budget in there.

I did mention Infinity as a Harman company though. I installed some 360's in a home theater system for my wife's boss and we were all impressed.
Sonnie is offline  
 
post #14 of 31 Old 01-30-08, 03:35 PM
Shackster
 
no. 5's Avatar
Aaron
 
Join Date: Jul 2007
Location: Wisonson
Posts: 49
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
avaserfi wrote: View Post
One such example is the Primus 360 (do not confuse this with the Primus 362).
What changes were made between the 360 and 362?

Our calculations are always correct, for we are gigantic brains.
no. 5 is offline  
post #15 of 31 Old 01-30-08, 03:50 PM
Chris
 
Join Date: Jan 2008
Location: Virginia, USA
Posts: 316
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
no. 5 wrote: View Post
What changes were made between the 360 and 362?
A reliable source told me that the the new **2 series is an attempt to reduce driver production costs, at the expense of some quality. Based on the measurements at stereophile.com of a 162 vs. a 160 I had on hand, this certainly appears to be the case.

However, I personally do not think the slight quality reduction matters greatly based on the use of these speakers in stock form. The cabinets are resonant structurally, and do not even use sufficient acoustic absorption materials internally. However, some of those Primus **0 raw drivers measure fantastically - essentially good enough to use in unlimited class sound quality speaker systems. The mid-range used on the 360 is a case in point - I bought a replacement driver from Harman and analyzed this unit. The characteristic response properties are unbelievable considering the speaker system in which it was used. But as you know, you can put the best drivers in the world in a shoddy cabinet system with a less than ideal crossover and ruin any potential said drivers may have.

-Chris
WmAx is offline  
post #16 of 31 Old 01-31-08, 11:06 AM
Chris
 
Join Date: Jan 2008
Location: Virginia, USA
Posts: 316
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
DS-21 wrote: View Post
The Neo3 is basically at 180deg at 3kHz, and there's no way a 4" midrange can match that.
For one, the mid Andrew mentions as 4", actually has a 3" effective radiating area. Second, as soon as you put a Neo3PDR on a flat baffle, it can have no more effective than a +/- 90 degree radiation pattern, due to the physical size of the baffle in relation to the wavelengths. It is trivial to match these two drivers to have near identical response out to a * +/- 60-70 degree horizontal axis when integrated around 2.5khz. Which is frankly, perfect in practical terms, for perceptual purposes. This accounts for the window of the 1st reflection angle vector typical in most situations, so a near mirror reflection occurs as opposed to one with substantial deviations relative to the on axis response.

Quote:
That's assuming one can stand that awful little tweeter. Forget the smooth FR, because it has lots of distortion and highly constricted dynamics. I've tried three variants of it, and I've learned my lesson every time.
What distortion would that be? I have measured this tweeter, and it has a notably low measured distortion. Certainly nothing near suspected audibility. Distortion measurements on that Zaph site also evidence it to have very low distortion.

-Chris

* In this thread, I intend to mean non-wave guide tweeters installed on baffles with very large radius edges, in the 3" or larger range, in order to maintain linearity on and off axis, thus minimizing diffracting characteristics of the baffle.

Last edited by WmAx; 01-31-08 at 11:14 AM.
WmAx is offline  
post #17 of 31 Old 01-31-08, 01:00 PM
 
Join Date: Jul 2007
Posts: 1,131
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
DS-21 wrote: View Post
No, the real problem is one of physics: a big piston will in general have more limited directivity at high frequencies than a small piston, unless the directivity of the small piston at the bottom of its passband is controlled.
Very true. Hence the need for proper driver integration. If the drivers are not properly integrated they won't sound good together. I have repeated this throughout the thread and stand by it. The area of driver integration is where it seems not enough research is done. Various measurements must be taken of each driver individually as well as in conjunction to see how they interact as the loudspeaker is a system and the sum of its parts.

Quote:
DS-21 wrote: View Post
That is exactly what I'm talking about. The subjective aspect is where it's more important. For my tastes, I'm willing to put up with some top-octave irregularities to get the mid-tweeter transition region really right. Others may have opposite preferences.
I think you have missed my point - If proper time and care is taken neither of these situations need be an issue. Through the previously stated process of proper driver choice, baffle design and crossover implementation one can address both issues in a way to remove them from the system.

Quote:
WmAx wrote: View Post
For one, the mid Andrew mentions as 4", actually has a 3" effective radiating area. Second, as soon as you put a Neo3PDR on a flat baffle, it can have no more effective than a +/- 90 degree radiation pattern, due to the physical size of the baffle in relation to the wavelengths. It is trivial to match these two drivers to have near identical response out to a * +/- 60-70 degree horizontal axis when integrated around 2.5khz. Which is frankly, perfect in practical terms, for perceptual purposes. This accounts for the window of the 1st reflection angle vector typical in most situations, so a near mirror reflection occurs as opposed to one with substantial deviations relative to the on axis response.



What distortion would that be? I have measured this tweeter, and it has a notably low measured distortion. Certainly nothing near suspected audibility. Distortion measurements on that Zaph site also evidence it to have very low distortion.

-Chris

* In this thread, I intend to mean non-wave guide tweeters installed on baffles with very large radius edges, in the 3" or larger range, in order to maintain linearity on and off axis, thus minimizing diffracting characteristics of the baffle.

Couldn't have said it better myself.

Last edited by avaserfi; 01-31-08 at 01:10 PM.
avaserfi is offline  
post #18 of 31 Old 02-02-08, 11:49 AM
Senior Shackster
 
MatrixDweller's Avatar
Zip
 
Join Date: Jul 2007
Location: Canada
Posts: 969
Re: Horn tweeters V.S. aluminum dome tweeters

It really all boils down to what sound you like the best.
MatrixDweller is offline  
post #19 of 31 Old 02-02-08, 01:43 PM
 
Join Date: Jul 2007
Posts: 1,131
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
MatrixDweller wrote: View Post
It really all boils down to what sound you like the best.
While that is a noble thought there is a tremendous amount of research in the field that shows there are certain characteristics of tweeters that are desirable while there are others that are not. Numerous blind tests were conducted with thousands of subjects in search of this data.

Look up Ian Paisley on the AES website for example of such research.
avaserfi is offline  
post #20 of 31 Old 02-02-08, 03:37 PM
Chris
 
Join Date: Jan 2008
Location: Virginia, USA
Posts: 316
Re: Horn tweeters V.S. aluminum dome tweeters

Quote:
DS-21 wrote: View Post
My point is, proper driver integration, absent some sort of directivity control of the bottom of the tweeter's passband, is impossible with most standard driver configurations, e.g. the 7" 2-way or MTM.
Whom is suggesting such an illogical combo as a 7" 'midrange' coupled to a standard direct radiation tweeter? Not Andrew. Not Chris(me).

Quote:
And frankly, the more separate drivers in a system, the more cost required in crossover (be it digital/active or passive) and the smaller the listening window will often become. That suggests a 2-way configuration with a reasonably-sized midbass (10" or bigger, say, or twin 7's or 8's) and a coaxial or waveguide-loaded tweeter as the optimum configuration for home use, IMO.
Such an execution would ultimately mean poor off axis dispersion(undesirable from the perspective of general rules outlined by loudspekaer perceptual research) if you use for example, an 8" for most midrange duty, in a band over about 1000Hz. Generally, such a large mid-range would also have have poor cone behaviour so far as internal break up modes, if used over 1000Hz, resulting in a poor waterfall response. The unit may still have a relatively flat on-axis response, but have various other technical issues when used in such a high band.

Multiple drivers(in a 3 way system as an example) work sufficiently when properly integrated. I do not see the issue so far as relevant performance is concerned in a properly integrated system. A 2 way system is very difficult to pull off while having desirable measured characteristics are dictated as desirable by perceptual research.

-Chris

Last edited by WmAx; 02-02-08 at 05:43 PM.
WmAx is offline  
Reply

Bookmarks

Tags
aluminum , dome , horn , tweeters

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome