|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
206.255.208.188
In Reply to: RE: No fooling posted by dave789 on August 27, 2016 at 17:48:09
It does amplitude-frequency equalization, too, in many cases.
Not by 20-30 db at the top! High quality tweeters naturally operate to 20 kHz and beyond without any need for boosting.
Technically, this does not make sense at all.
Perhaps to you.
As Kal indicated, using a four inch piston to reproduce a one inch wavelength (and smaller) creates inconsistent directivity through its range. Then, placing a large number of them together spaced greater than the wavelengths reproduced creates copious amounts of comb filtering, aka "chaotic interference" which kills coherence.
What does "forcing" technically mean?
Using artificial means for a driver to reproduce frequencies beyond its inherent bandwidth. A 4.5" driver is good to about 3 khz for consistent directivity. That's why they call them midranges!
Follow Ups:
1. Just proceed with the choice of full-range coneEclipse TD508Mk3
What Hi fi 5 star
("Even the best of their conventional rivals, such as the ATC SCM 11 and KEF LS50 speakers, sound vague and imprecise in comparison.
Read more at http://www.whathifi.com/eclipse/td-508-mk3/review#uCDUzOmjfDZ4Ypw4.99)Eclipse TD-712z Mk.2 (a single 4.7" driver cone)
Stereophile 2016 Recommended Component Class A (Restricted Extreme LF)2. Proceed with some remedy other than crossover
Bose 901, 402, 802
3. Use crossover (not using the cone(s) for full frequency range)Of course, this choice has side effects. One is shown in the displayed picture (Adam Audio A3X 2-way active near-field studio monitor loudspeaker).
Edits: 08/28/16 08/28/16
Look at the referenced review in Stereophile here . View Plot 4.
"The dispersion is superbly even below 4.35kHz, but there is a sharp discontinuity at that frequency, with a rapid rolloff to the speaker's sides...
As RD notes, this is not a speaker that will go very loud or very deep, and tonally it is not all that neutral.
To each his own.
Actually, since I am a coherence freak, I am very much in favor of single driver designs that:
1. Deliver near ten octave response without active equalization
2. Exhibit consistent directivity across the bandwidth
My Sound Lab U-1PX speakers meet those criteria. :)
. . . . . . .
You are provided some latitude to vary the response to accommodate your room or specific recording content via controls on the backplate.
Lows and mids have a +3/-6 range while the top only offers attenuation. Mine remain flat.
Cool speaker!Does your room have much high frequency absorbers? The high knob appears to be at max.
Edits: 08/28/16
Does your room have much high frequency absorbers? The high knob is appears to be at max.
I use some diffusion. You can see pics in my gallery.
Once again, MAX=flat. Your only option is attenuation.
Beautiful speakers!
I also like the space and the bass traps behind those panel speakers.
I spent considerable time experimenting with speaker and bass trap position measuring the results each time to achieve the final room response.
An RTA plot would necessarily show more variation, but I find they sound quite neutral.
This post has been interesting to read. You have been very Kind E-Sat. I can't think of anyone I would rather have responding to this. My friend has a pair of Bose 901's too. He thought they were good. Until he tried a pair of real speakers. It is pretty obvious that the top end is lacking. I think of their accompanying equalizer as a box that is intended to make up for their weaknesses as performing some sort of "black magic"
It is pretty obvious that the top end is lacking.
Well, its there but as you say lacking in natural air and transparency to these ears.
as performing some sort of "black magic"
No *magic* - just addressing the inherent bandwidth limits of 4" drivers. Which works just fine at the bottom with wavelengths measured in feet.
There is no pre-determined scientific rule that 10dB is "natural" and 20dB is "artificial" "mammoth" "forced." You, like many Bosh bashers with poor engineering background, merely expressed your prejudice using words containing your subjective hatred. Your other comments are similarly nonsense.In the engineering point of view, your claims has no value to discuss.
A engineering choice in a speaker may be different from that in dozens of other speakers one knows. That is not a logical basis for bashing. I do not bash Quad ESL merely because it has a design choice different from that in dozens of other speakers I know.
You did not bring objective measurement showing that the end result is poor.
If you said you did not like the sound of a specific Bose model you actually auditioned carefully, I would fully respect that.
Edits: 08/28/16 08/28/16
There is no pre-determined scientific rule that 10dB is "natural" and 20dB is "artificial" "mammoth" "forced."
I can't think of a single conventional speaker that requires any active equalization at the top. Please cite an example.
You did not bring objective measurement showing that the end result is poor.
The concepts of uniform directivity and comb filtering are well established. Read up on them if you'd like to understand.
It is a commonly understood engineering practice when using conventional drivers to choose those where the piston size is smaller than the wavelength to reproduce. The directivity sharply narrows beyond those frequencies whether you equalize them or not.
Click here for a wavelength calculator.
"I can't think of a single conventional speaker that requires any active equalization at the top. "Thank you for expressing this. Not surprising. Internet Bose bashers have been like this, which is very well known.
Active or passive is not a big deal here.
How did you form a belief that all conventional speakers systems (except Bose) have no amplitude-frequency equalization at the top by some circuit (active or passive) before the driver?
How can you claim that a speaker system is inferior, if a speaker system has such a circuit (active or passive)?
Edits: 08/28/16
Active or passive is not a big deal here.
What is relevant is the magnitude.
How did you form a belief that all conventional speakers system (except Bose) have no amplitude-frequency equalization at the top by some circuit (active or passive) before the driver?
I view frequency response, waterfall and directivity plots of individual drivers. Tweeters don't need boost at the top. If anything, modest amounts of EQ is used to attenuate resonant spikes.
How can you claim that a speaker system is inferior, if a speaker system has such a circuit (active or passive)?
Ultimately, it lies with the listening experience. The primary limitation of the 901 design for me is its unnatural imaging where individual instruments are stretched across the back wall. The lack of HF refinement due to using high mass drivers arrayed as they are follows.
. . . . . . .
you don't understand what uniform directivity means. You can see the results in the other post about the Fujitsu Ten Eclipse.
Its absence results in poor and unnatural imaging. Read some of Floyd Toole's work on that topic to learn about it.
As for exhibiting gross amounts of comb filtering, read Kal's post again.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: