[hebrer]

Re-post from diyaudio.com:

Hi, when reading the "Get Better Sound" audio system set-up manual, I was intrigued by what the author Jim Smith claims about the 192 Hz to 384 Hz frequency region:

Tip #44: The one thing that your system must have to be musically satisfying
...
In my years of experience in voicing systems, I've found that a system must have a flat-to-slightly-elevated response curve in the critical region from approximately 192 Hz to 384 Hz. Yes, I said it could be slightly elevated. Of course, if a system covers the area properly, there's no need. But not all do.

This range is from one-half octave below middle C – (when the scale is 256 Hz) – to one-half octave above it. Therefore, the area between approximately 192 Hz and 384 Hz is one musical octave in width.

When a speaker (or electronic component or cable) seems to be lean in this area, the sound will usually prove to be boring musically. Amazingly, components that are lean in this area are often admiringly described as highly resolved, precise, articulate, etc. My description? BORING...

But when this region is either flat, or perhaps elevated by a very slight amount, the music is infinitely more involving. Strings have more body. Brass will have more "weight," and a more "burnished" tone.

Orchestral music will have a balance (and subjective power response) more akin to live sound in a concert hall.

Vocals will have much more palpable presence. That "reach out and touch it" impression.

The sound will be lusher. Guitars will ring out with a beauty that almost touches your soul. In short, you'll find yourself affected by the music.

Aside from addressing the smooth bass in the 25-300 Hz region, this is probably the most important frequency response area that a component or system must get right for ultimate satisfaction. For example, if a system is exceptionally detailed or has powerful bass, but it doesn't get this area right, it'll be fatiguing to listen to over a period of time.
...
I've observed this phenomenon for many years. I wish I could tell you why it's so, but I don't know. I just know it is. For me, it's foundational for ultimate musical satisfaction.

Apart from being curious if your experience is similar, I am more interested to hear your opinion on what type of speaker enclosure might best take care of the 192 Hz to 384 Hz region.

I am about to build new speakers using 10" fullrange driver (http://commonsenseaudio.com/an10cfspecs.jpg). Forgive my ignorance, but I notice this particular driver has lowest impendance in the 192 Hz to 384 Hz region. What practical implications does this have?

Thank you for sharing..... Peter

[JeffB]

Interesting question.  I don't know the answer.  I was just reading the other day from one speaker manufacturer claiming great sound was all about the tweeter.  And others claim it is best to keep the cross-over away from the critical 2k-3k area.

[FullRangeMan]

Re-post from diyaudio.com:

Hi, when reading the "Get Better Sound" audio system set-up manual, I was intrigued by what the author Jim Smith claims about the 192 Hz to 384 Hz frequency region:
Apart from being curious if your experience is similar, I am more interested to hear your opinion on what type of speaker enclosure might best take care of the 192 Hz to 384 Hz region.

I am about to build new speakers using 10" fullrange driver (http://commonsenseaudio.com/an10cfspecs.jpg). Forgive my ignorance, but I notice this particular driver has lowest impendance in the 192 Hz to 384 Hz region. What practical implications does this have?

Thank you for sharing..... Peter

Hi,
By the Super10CF freq.range chart in your link, it do not suffer from this problem, then you should stuffing inside the box to level-up the Super10CF bass below 100Hz.

I think the author are referring to the usual and very common depression in this frequency range(200 - 400Hz) found in most low cost woofers and midranges.
This is a problem in the speaker project, maybe cone break, as you can see in this Beyma 10AGN frequency range chart image below.
I do not know as to flat this dip, If you stuffing inside the box to up it, the bass below 120Hz also will increase, use a filter to rise this freq.range is a radical solution, not appreciatted by single driver fans. Good Luck

[antonc]

Re-post from diyaudio.com:

Hi, when reading the "Get Better Sound" audio system set-up manual, I was intrigued by what the author Jim Smith claims about the 192 Hz to 384 Hz frequency region:
Apart from being curious if your experience is similar, I am more interested to hear your opinion on what type of speaker enclosure might best take care of the 192 Hz to 384 Hz region.

I am about to build new speakers using 10" fullrange driver (http://commonsenseaudio.com/an10cfspecs.jpg). Forgive my ignorance, but I notice this particular driver has lowest impendance in the 192 Hz to 384 Hz region. What practical implications does this have?

Thank you for sharing..... Peter

Seems the new sensation Alpair 7 from Mark audio fits this requirement.   

[JLM]

Which portion of the frequency spectrum is most important is open to opinion but I wouldn't disagree.  Note that I'm absolutely opposed to chopping off the bottom octave of music just to hold to the single driver principle.

Since driver cone/dome materials are acoustically much more transparent than anyone would like, the best cabinets are those with a diffuser/sloped panel behind them to direct the rear wave (1/2 of the driver's output) away from bouncing back at the driver (and thus through that cone/dome material).  Note that since no musical source I'm familar with radiates sound forward and backwards at once I'm opposed to dipoles and bipoles.  Also note that since no musical source I'm familar with radiates sound in and out of phase I'm further opposed to dipoles. 

[Teflon]

From a listeners perspective, sound is rarely only received from a single source directly, we also often hear sound that has been reflected off boundaries. Perhaps there are circumstances when your objection to dipoles is worth re-visiting.

[rajacat]

Which portion of the frequency spectrum is most important is open to opinion but I wouldn't disagree.  Note that I'm absolutely opposed to chopping off the bottom octave of music just to hold to the single driver principle.

Since driver cone/dome materials are acoustically much more transparent than anyone would like, the best cabinets are those with a diffuser/sloped panel behind them to direct the rear wave (1/2 of the driver's output) away from bouncing back at the driver (and thus through that cone/dome material).  Note that since no musical source I'm familar with radiates sound forward and backwards at once I'm opposed to dipoles and bipoles.  Also note that since no musical source I'm familar with radiates sound in and out of phase I'm further opposed to dipoles.

On the contrary, if you went to hear an orchestra and listened from the backstage rather than in the audience, you would still hear the music, wouldn't you? So it follows that the instruments are radiating sound in all directions although the sound energy would be predominantly directed in the direction the instrument is pointed. Therefore, it seems that speakers should try to mimic the natural radiation pattern rather than just direct sound on the forward plane. Bipoles have a more natural dispersion pattern than monopoles.

-Roy

[TONEPUB]

Everyone says something different, that's why there are so many different speaker designs!  And they all claim to be the best...

[Danny Richie]

Maybe this will help:



I always felt like 300Hz to 500Hz was the heart of the mid range. This is where you absolutely don't want to split the signal into dissimilar drivers are cause a phase shift. Crossing over just below it (below 200Hz) or just above it (1kHz or more) works fine. Crossovers in the 2kHz to 3kHz is no problem at all.

I have also measured and tested with some of the drivers that the original poster mentioned.

Your best sounding mid-range will be from an open baffle, but you will have to at least add a first order crossover to it to pull the lows off of it so it won't get beat up. You'll also need something else to cover from 200Hz and down.

Another thing to keep in mind is that you will have to add a compensation circuit to flatten out the response or it will be so hot that it will take your head off. With the 12" version I had to add two LCR networks also to control a couple of really hot peaks.

And the low impedance in that range (192 Hz to 384 Hz region) is typical and no problem at all.

[kyrill]

"...must have a flat-to-slightly-elevated response curve in the critical region from approximately 192 Hz to 384 Hz."
Nicet to read what I (just,last month)) found out.
I Have a  DEQX system ( Preamp with digital 3 way Xovers, room correction and parametric 10 band equalizers) and can play with frequency to my will ( a blessing and a curse..)

and found out with +2 db between 100 hz and 300 hz ( flat form there to 1 khz within 1db)  the sound sounds so much more lifelike, the cello gets more he wooden body that I love so much and so on.
I presume in  a perfect room you dont need it when the freq is ruler flat incl room, but hard to get. This 2db does do the trick for me
BTW my Visaton B200 in OB covers the range between 150Hz-8khz