Flat Response

[Guest]

Re: Flat Response

Guys, I think y'all are getting your panties in a bunch and imagining disagreements where none exist. Can we all agree that, as a general rule of thumb, a good speaker/room combo will have:

Flat on-axis response (anechoic or quasi-anechoic)

I doubt very much that all will agree Dennis. You have to view this thread, as I did, as an extension of other threads, such as the student builds, the Orion update, etc, etc. (take a look at them if you have any doubt).
When the OP started the thread, I knew that he is referencing, as most do on DIY sites like this, the on axis response of the source, not the measured at listener position FR (which very few do, how often do you see those??).
You hear claims that "a flat response" is not ideal, or does not guarantee good sound, etc, etc., because they have used a program like FRD to simulate "a flat response", built it...and not liked the sound.
I also have no doubt that this is what Deward doesn't like about his speakers.

cheers,

AJ

[DDF]

Re: Flat Response

I doubt very much that all will agree Dennis. You have to view this thread, as I did, as an extension of other threads, such as the student builds, the Orion update, etc, etc. (take a look at them if you have any doubt).
When the OP started the thread, I knew that he is referencing, as most do on DIY sites like this, the on axis response of the source, not the measured at listener position FR (which very few do, how often do you see those??).
You hear claims that "a flat response" is not ideal, or does not guarantee good sound, etc, etc., because they have used a program like FRD to simulate "a flat response", built it...and not liked the sound.
I also have no doubt that this is what Deward doesn't like about his speakers.

cheers,

AJ

As I've stated flat response is not my ideal, I'll also add that your generalization doesn't apply to my case as I take highly accurate measurements for all my designs and am very analytical with my design approach.

Just one data point.

[Guest]

Re: Flat Response

As I've stated flat response is not my ideal

Nothing to dispute there. Subjective choice.

I'll also add that your generalization doesn't apply to my case

What generalization? "Most"?
I honestly didn't take a poll or have concrete statistical data. Just an observation over the years. One data point maybe?

I take highly accurate measurements for all my designs and am very analytical with my design approach.

Great news.
Can we see (measurements) what the off axis looks like, in these formerly flat on axis designs?
TIA

[mzisserson]

Re: Flat Response

In Floys Toole's book he talks about the transition from speaker to room which occurs around 250Hz in an average living room. As Fq increases, so does the precieved directivity. This is something I account for in my designs, or at least try and consider. Controlling the response of the speaker and its response directivity/lobing is a great idea, but I do not think it captures it all.

I admit I am no professional acoustician, but these concepts make sense, and from 30,000 ft. (Basically what our ears hear and average) if they are well considered, you will have a very successful loudspeaker.

This is were the linne gets blurry for me of what truly makes a good sounding loudepaker. I have heard many that consider every possible option and phase is perfect, directivity is controlled, power response is amazing, response is flat, and they really did not sound very good.

This is where Tool's book and its skimming of Psycoacoustics is truly a great education. What we think is important vs. what our body thinks are two different things.

Just some thoughts.

[Deward Hastings]

Re: Flat Response

You hear claims that "a flat response" is not ideal, or does not guarantee good sound, etc, etc., because they have used a program like FRD to simulate "a flat response", built it...and not liked the sound.
I also have no doubt that this is what Deward doesn't like about his speakers.

You think SL used "FRD" to design ORION, and Behringer used it for the 2030A? Both of which I like just fine, thank you, with a bit of hf roll-off . . .

What color is the sky on *your* planet ? ? ?

[Zilch]

Re: Flat Response

Also suggest that we extend the conversation beyond Linkwitz and Geddes references. IMO their ideas are still in their infancy in this area compared to many other sources. Lets raise the bar beyond diyaudio.com!

Infancy?

How about Villchur, since several members have found it appropriate to mention the AR legacy?

This vintage sample AR3a has nominal 150° (-6 dB) horizontal beamwidth through the midrange, stepping to a substantially narrowed 90° at 10 kHz and further diminishing to 60° in the top octave.

There is significant asymmetry in the range of 1 - 2 kHz generated by an outboard null.

Generally, the response is chaotic, but the trends are clear:



Compare to the maps I posted earlier for the directivity link between two purveyors of concert hall realism, 40 years apart:

http://techtalk.parts-express.com/showpost.php?p=1665878&postcount=49

[Frequency response, anyone.... ;) ]

[dantheman]

Re: Flat Response

True, your exact words were:

So you lied IOW. You should put more effort into defending your position or refuting your adversary's position rather than attacking your adversary personally. You will not win either way it seems, and your displayed personality is just making you look like a jerk. The facts are just not on your side and that's why you feel the need to attack me personally(b/c you aren't winning an intellectual argument so you drag it into the gutter). It would seem you can't resist it. I've even cordially invited you over--twice. Offered free drinks--and good stuff too! Been nothing but friendly toward you. Even tried to nip the ad hominem in the bud on this thread. You did manage to get in one reasonably civil post and now you've just gone haywire. You really should be ashamed of yourself.

A different row you could hoe would be to just admit you are not correct. Your previous assertions were simply wrong and make no logical sense and therefor you cannot win logically.

Just offering some help.

Also a lie.

I'll admit that I've never had the opportunity to listen to an orchestra from a "captain's chair" hanging 10 ft. over the conductor . . . but I suspect it would sound "too bright" .

Hmmm. 10ft over the conductor sounds like an expensive seat to me. I'm no expert. Even normal seats 10ft away can't be cheap.

And you know that how ? ? ?

You said so just a couple pages back. I described your speakers polar pattern--the Orion. You say you like them, but said it was a lie when I said you like that polar pattern. That's why I replied you can't have it both ways.

You seem to believe that the speaker needs to have very narrow beam width in the top octave and much wider beneath it(correct me if I'm wrong here, but that's what I've gathered)

You're totally wrong, I've never said that, but there's (obviously) no point trying to "correct [you]" . . . you don't read what is written, and reply only to your own fictitious strawmen.

Of course I didn't say you did. 1,2,3, is this a pattern yet?

No, I just get annoyed at some idiot here who doesn't seem to understand the difference between the two (which include, significantly, switchable high and low frequency response compensation on the 2030A).

Ad hominem. Interesting and very adult. I mean really Deward, read that first sentence. Now go to your room and don't come out until you can get a better attitude.:p Yea, an unfortunate pattern.:o

"Flat response" sells (to the ignorant), and it's marketing that generally makes such decisions. Plus, it's not an unreasonable choice *for monitors*, as it will encourage whoever does the mix to roll off the high end . . .

Hmm, studio monitors have a flat response. Does that mean people who buy studio monitors are ignorant as they bought a flat response? What curve then would the informed look for? If the highs are already rolled off while being mixed in the studio, do we want to do it more at home in your opinion or should we use a little EQ to boost it back up? I don't hear a need to, but I have a lot of recordings of multiple genre and I'd prefer front row tickets so this is easy for me. The only reason I don't buy them is the price. Recordings cost the same no matter how accurate your stereo.

Aye,

Dan

[DDF]

Re: Flat Response

Nothing to dispute there. Subjective choice.


What generalization? "Most"?
I honestly didn't take a poll or have concrete statistical data. Just an observation over the years. One data point maybe?


Great news.
Can we see (measurements) what the off axis looks like, in these formerly flat on axis designs?
TIA

Its actually an objective choice, attempting to obtain the most realistic perceived sound with the minimum of annoyance. Calling it a subjective choice is to denigrate the validity of the choice.

This very much reads like a generalization (ie "they"), painting all who have found through study that non-flat targets can be more accurate as being without measurement acumen or knowledge:

"You hear claims that "a flat response" is not ideal, or does not guarantee good sound, etc, etc., because they have used a program like FRD to simulate "a flat response", built it...and not liked the sound."

Sure, I'd be happy to illustrate an example.

Here’s a really good example of an older 2 way I did a number of years back, with a 4.5” woofer and 1” tweeter.

First design drove the xover low and fairly steep to get rid of the break up and ensure a nice off axis response, before the woofer beams.

Here are the driver responses and on axis result for the first attempt (text book flat as possible) : "1.gif"


First, here is the basic xover "2.gif":


Here is the off axis "3.gif":



Here is the reverse null "4.gif":

Even the impedance was very benign and never capacitive "5.gif":


Based on the comon DIY wisdom, this is near « perfect » : flat out to 30 deg with a nice gentle top end roll off, deep reverse null, no peaks in the off axis (only nulls), very flat on axis, easy load on the amp.

It sounded grating. The tweeter wasn’t overdriven (I measured THD).

After many iterations involving tweaking by ear and mic, "6.gif" and "7.gif" show the final result (see follow up ost, only 5 pics allowed per post). It sounded far more realistic and relaxed over far more source discs and gave up nothing on the « hifi » CDs. BTW don’t worry about the absolute scales, the first graphs were scaled down by about 5 or 6 dB.

On paper, this should have sounded far worse: woofer resonance far less suppressed, less flat, xover much higher than what is fashionable.

This sounded more accurate and less grating than the first attempt. System is Bryston amp, homebrew passive pre (less than 0.1 dB error 5 Hz to 40kHz, no ultrasonic peak, channel separation > 100 dB) and a fairly heavily modified MSB Link Dac (measures near perfectly).

[DDF]

Re: Flat Response

After many iterations involving tweaking by ear and mic, "6.gif" and "7.gif" show the final result (see follow up ost, only 5 pics allowed per post).

Here are the last two graphs.

[DDF]

Re: Flat Response

Infancy?

Yes, I believe that both Geddes and Linkwitz thoughts on room loading and optimal directivity are still in their infancy and not yet well developed, when compared to the like of Harmon (Olive) and some others. But I can see this being a rat hole so its the last I'll discuss on this point and in hindsight shouldn't have brought it up.

[Guest]

Re: Flat Response

You think SL used "FRD" to design ORION, and Behringer used it for the 2030A? Both of which I like just fine, thank you, with a bit of hf roll-off . . .

No, but most here do...just as I said.
The one axis distortion you prefer is purely your subjective choice and has no basis in science for validity, unlike the native response of the Behringer, or any other high quality monitor from JBL (as I linked), Genelec, etc, etc, etc.

Its actually an objective choice, attempting to obtain the most realistic perceived sound with the minimum of annoyance. Calling it a subjective choice is to denigrate the validity of the choice.

:rolleyes:

First, thanks for the graphs. They are excruciatingly small (and I have 20/20 tested '08 vision), making it difficult to see detail (no way to simply attach as a full sized pic??), but I can see the overall trend.
A 4.5" two way crossed at 1.5k with a very broad dispersion 1" dome is a bit atypical for a 2 way, putting a lot of power at HF vs LF, but that's ok.
Did you at least listen with a woofer or subwoofer? That seems more like a 3 way missing the woofer to me ;). But you said it sounded bright and harsh, subjectively, to you. No distortion data to look at, but you said it was fine. Ok.
Let's add some woofers and different ears/room:
http://www.soundstage.com/equipment/...ima_salon2.htm
(readable graph):

Same "flat" on axis response, with very broad dispersion over a 30deg window all the way to the top. Now read the subjective perception, specifically about HF. Hmmmm.
But wait, there's more Revel Salon2. Different ears, different room, same extremely flat/broad 30 deg window

...and completely different perception...from yours.
Yet you insist it is not a purely case specific, subjective choice by you..and others?

This very much reads like a generalization (ie "they"), painting all who have found through study that non-flat targets can be more accurate as being without measurement acumen or knowledge:

Let's be clear who is doing the "studies" via measurement acumen here. That would be those who sell products in the world marketplace, to stay in business, such as Harman, Genelec, Behringer, et al.

"You hear claims that "a flat response" is not ideal, or does not guarantee good sound, etc, etc., because they have used a program like FRD to simulate "a flat response", built it...and not liked the sound."

Yes, that was a near direct quote of mzisseron, but I've seen the same type of comment here a thousand times (about "A flat response" vs perceived sound). That is what I'm referring to. And no, you won't see any off axis measurement (and often no on axis :eek with many of these on axis sim designs where it was decided that "a flat response" guarantees nothing .

cheers,

AJ

p.s. ask Dano if it wasn't the student build/Orion3 threads, that spawned this one


also let me throw in one more for good measure http://www.soundstage.com/equipment/...lex_katana.htm, which include "flat" 30 deg window measurements...and subjective perception by yet another set of ears/room. Bright? Harsh? Hmmm

[r-carpenter]

Re: Flat Response

So, AJ let me try to get this straight. What you are saying is that a loudspeaker with less of the linear distortions on and off axis will sound better in the semi reverberant space? I am getting a bit lost here. We are talking about linear distortions for starters, correct? And yet we resort to subjective descriptions in the end. Oh boy.

[mzisserson]

Re: Flat Response

So, AJ let me try to get this straight. What you are saying is that a loudspeaker with less of the linear distortions on and off axis will sound better in the semi reverberant space? I am getting a bit lost here. We are talking about linear distortions for starters, correct? And yet we resort to subjective descriptions in the end. Oh boy.

Roman,
You have it it on the head perfectly. :D

The science is great because you can prove one way or another what is, is what is. And the science is definitely paramount....

BUT: Coorilating it to what we percieve is far more important. Identifying what is important is very important, and all thing should be considered, but are never absolute.

[Deward Hastings]

Re: Flat Response

And yet we resort to subjective descriptions in the end. Oh boy.

In AJ's world *his* "subjective" observations are "objective", and everyone else's are, well, groundless and lacking in "objective" confirmation. Funny, that . . .

[DDF]

Re: Flat Response

First, thanks for the graphs. They are excruciatingly small

Click them, they enlarge (they're attachments)

A 4.5" two way crossed at 1.5k with a very broad dispersion 1" dome is a bit atypical for a 2 way, putting a lot of power at HF vs LF, but that's ok. Did you at least listen with a woofer or subwoofer?

It's alow sensitivity design with an f3 (sealed) near 70Hz. At normal modest sound levels, it sounds fine....unless your conceding that a early bass roll off requires a non flat response elsewhere??....

I also listened to it with a single 500W sub, set up using MLSSA in room (the amps has settings to parametric eq 3 frequencies).

Same "flat" on axis response, with very broad dispersion over a 30deg window all the way to the top. Now read the subjective perception, specifically about HF. Hmmmm

But wait, there's more ...and completely different perception...from yours.
Yet you insist it is not a purely case specific, subjective choice by you..and others?

So let me see if I have this right. First, audio reviewers opinions are meaningless and biased (your oft stated position)...it seems unless they agree with you. OK, noted.

Secondly could this not be an indication that you can't tell everything about a speakers spectral balance by these graphs? Here's the kicker: I've heard the Salon 2s in apurpose built listening room: I liked them and found them accurate. Throws a wrench in your theory that this is all about my preference.

also let me throw in one more for good measure http://www.soundstage.com/equipment/...lex_katana.htm, which include "flat" 30 deg window measurements...and subjective perception by yet another set of ears/room. Bright? Harsh? Hmmm

See above. One final note, I suspect these listeners, being paid reviewers, have treated and set up their listening rooms to be "tuned" for sound reproduction. I really haven't, as my listening space is foremost a living space. I tune my speakers to the space, not vice versa. Could this not have an impact on the perceived sound?

But weren't you the one who said that a good speaker should be room agnostic? So, the only answer in your mind must be that I can't judge good sound. As a debating approach, its lazy, mean-spirited and baseless.

Dave