Most critical frequency response area? 192 Hz to 384 Hz

[hebrer]

Hi, when reading a 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

[Bigun]

I never heard of this claim before about that particular frequency range. Sounds like a cart load of horse waste to me.

[human.bin]

what does he mean by being right in the area? only slightly elevated spl instead of lean flat response on paper? isn't it the area where a box speaker will tend to suffer from baffle step when in room?

where is the excerpt from?

[Pano]

Get Better Sound

[jerryo]

Hi panomaniac,
I had a quick look at the link you provided and I have to say the book looks interesting.
I presume that you have a copy; if so, could you give us a review of it and say whether you think it is worth buying?
Thank you.

Cheers

[chrisb]

Originally Posted by Bigun

I never heard of this claim before about that particular frequency range. Sounds like a cart load of horse waste to me.

stranger things have been found to be "true" without being "proven"

[sq225917]

mess about with a digital EQ and find out.

[hebrer]

Hi jerryo,

I have the book also and while not able to give you a "review", I can tell you that for me it proved a very cost effective treatment of "upgraditis". In audio world full of opinions and personal preferences, a little knowledge based on sound physical principles and confirmed by years of experience goes a long way. When seen as a book, it is definitely not cheap. When seen as (knowledge of) an audio component, I have not found a better value yet. It saved me hundreds of dollars potentially spent on "trial & error" or "plug & pray" upgrades to my audio system. Just my 2 cents.

[hebrer]

On a related topic:

How much would you think that the sound of a speaker in the 200-400 Hz region is shaped by:

- frequency response of the driver

- cabinet

- room and room treatments?

I just presume it is a combination of all three factors but unlike in higher frequency region, the effect of the cabinet and the room may be stronger.

If so, does the enclosure play lesser/equal/greater role than the frequency response of the driver given by the manufacturer, particularly in the 200-400 Hz area?

Thanks for your thoughts.

[ThorstenL]

Hi,

Originally Posted by hebrer

Hi, when reading a 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 think Jim is too restrictive and imprecise at the same time.

The fundamentals of many instruments and the human voice fall into this range.

I would personally say that it is important that this range is in the correct proportion compared to frequencies above and below, not to be flat in itself.

However I would add that it is the in room POWER RESPONSE and NOT the (pseudo)anechoic on axis frequency response that should be flat in this range. The on axis response if flat as well should be accounted as major bonus.

In general terms this implies a system with controlled directivity in this range, which pretty much means a large front horn, e.g. the big Avantgarde Trumpets Jim used to sell, or a dipole or a cardioid system. Conventional vented boxes, especially narrow fronted ones often cannot deliver this.

Originally Posted by hebrer

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?

Looking quickly at the driver it would seem that it requires front and rear horn loading to offer a balanced frequency response, so I hope you intend to buildsuch a cabinet. A reflex box would give a most uneven frequency response.

As to impedance being lowest, it means this range will be somewhat suppressed when driving the speaker from an Amplifier with high output impedance (OTL, SET) compared to a conventional amplifier, nothing more and nothing less.

Ciao T