Sound quality is in the ear of the beholder…

tajanes

A speaker’s high frequency extension and dB level, sometimes described as harsh or smooth, aggressive or rolled-off (the reviewers have many) may be objectively measured, but more likely are subjective based upon age…

I remember when I was in college listening to a pair of early Wilson’s (it being a good guess that a college student wasn’t going to be buying those anytime soon, the dealer fortunately was willing to let me sit down and listen).  Overall I was impressed.  They were big and sounded even bigger. I had just started my quest into experiencing the likes of Linn, Naim, McIntosh…  But to this day I remember thinking that the tweeters were harsh and too independently locatable.  Strangely I remember saying to myself, give me a blindfold and a BB gun and those puppies (tweeters) are going down.

As we age, it’s not a surprise that even absent a unique hearing injury/issue, that our ability to hear, especially higher frequency ranges, attenuates.  It’s a slow and generally an unnoticeable transgression (starting in earnest in our ~30’s).  As such, we fortunately compensate, probably w/o knowing the extent.  I’ve been recently Googling and have been surprised by the age of onset and the extent (it’s not a pretty picture).   Here is one link (a bit older, but on par with many others) https://phineasgage.wordpress.com/2007/10/13/audiophiles-and-the-limitations-of-human-hearing/

So, now I ask, to what extent has Wilson improved it’s (tweeter selection) high-end, or is it just my older, and older-subjective, hearing sensitivity…

At the diy events, sound-wise for me, it comes down to comparing the smoothness of transition between the drivers (the best being seamless be they 2 or 3ways, i.e. sometimes I cannot tell) and the extension and perceived dB level of the top end.  So is it live or is it Memorex, or is it ...age?  Maybe the old JBL’s with their hf attenuator controls had it right.  But this all seems to provide some basis for hearing preferences for designs...

Thoughts?

Kornbread

I have been second guessing my choices on this latest build because it has just over a 2db rise from ~12 -20k but sounds fine to me.  It is there and measurable but I don't know it it is a real problem that needs dealt with or better left alone.  We have annual hearing tests at work and due to age, inadequate hearing protection in a too loud factory, and this damn ringing that never quits, my test are showing some high frequency loss so I always second-guess what I hear.     

Tom_S

I know my hearing is damaged. Anything above 10K is gone and there are narrow notches from 4-8K. But I'm really sensitive to the sibilance area and overly bright treble now. Smooth & flat works best for me - maybe even a little downward tilt beyond 1K, but not too much. Luckily my speaker design skills are finally improving, so I can actually live with what I build. 

Just a point of reference - I haven't really auditioned any commercial speakers in well over a decade, so what do I know? 

jhollander

IMO don't discount your hearing, as you're a more experienced listener you can hear things others don't. Also I'm not a fan of killing the top end of many rising response tweeters as the off axis response sufferers.

Tom_S

jhollander said:

IMO don't discount your hearing, as you're a more experienced listener you can hear things others don't. Also I'm not a fan of killing the top end of many rising response tweeters as the off axis response sufferers.

That's part of the curse of this hobby. The extreme example: My wife or son want me to hear a song and holds their phone up in my face. I can't even hear the music. My only thought is - get that horrid sounding device away from me!

Wolf

Phones are not music devices, they are phones. I say that all the time...

Tom_S

Wolf said:

Phones are not music devices, they are phones. I say that all the time...

+1

dcibel

I use my phone to play music all the time, but the sound keeps coming out of my big 3-way speakers. Not sure I have this technology stuff figured out.

jhollander

I find it interesting how some of the music on my home stereo sounds like crap in my car, and music I like in my car sounds meh in the house.

tajanes

So, if I cannot hear 20kHz, 18 or...  I'm more open to selecting tweeters with smoother and wider dispersion patterns over mere extension.  

Suggestions, what tweeters have you seen / used that provide a wide and smooth-ish off axis roll off?

 thx

 

jr@mac

Most ribbons and 3/4" dome tweeters have fairly good dispersion. Of course, baffle geometry plays a significant role in our perception of that behavior as well. 

jhollander

I thought the Peerless DA25TX performed well, though my implementation was suspect...

On baffle response 

dcibel

With wide dispersion you get baffle diffraction, so how smooth the off-axis response is dependant mostly on the baffle geometry, and to a lesser extent the tweeter's face plate.

I tend to prefer tweeters with more narrow dispersion, as this reduction comes with less baffle diffraction and less room interaction. You can also end up with a more consistent directivity index for your speaker. For dome tweeters, waveguides provide this benefit, as well as improvement to the performance at the lower end of the tweeter's frequency spectrum. 

Here's the Wavecor TW030WA11, a large 30mm dome with a small waveguide. This is measurement by AudioXpress, on a 14" x 7" baffle:

By comparison, this is the TW030WA13, a neo 30mm tweeter, but without the waveguide on the same 14" x 7" baffle.

tajanes

thx !

The Peerless DA25TX looks to have a very smooth and consistent roll-off (out above 6.5Khz). Nice.

Interestingly, yes the waveguide manages out the freq issue around 2.9KHz. I'd agree with benefits of narrow for vertical (floor and ceiling interaction), not so sure on horizontal.   

dcibel

The off-axis peaking at 3kHz that I posted is simply a result of the baffle width. This will be a common trait for pretty much any dome tweeter with a flat faceplate on a flat baffle, you only need to go as far as observing some simulations in some software like Edge to see the results. In any case, what it comes down to is that if you do all your design work on-axis you may be missing some of the picture as the on-axis here has a dip at 3kHz that isn't present off-axis. A waveguide works to focus that off-axis energy forward, which can decrease the diffraction effects significantly.

rjj45

Recent build with large baffle roundover (2.5 inches radius) achieved via kerfing BB.
The NeoCD 3.0 ribbon tweeter came out extremely smooth off axis.
I am now convinced that baffle diffraction can screw up most tweeter FR.

4thtry

tajanes said:

thx !

The Peerless DA25TX looks to have a very smooth and consistent roll-off (out above 6.5Khz). Nice.

Interestingly, yes the waveguide manages out the freq issue around 2.9KHz. I'd agree with benefits of narrow for vertical (floor and ceiling interaction), not so sure on horizontal.   

Here are my SideTower polars that use the DA25TX. 

rjj45

very nice!