Flat Response

[Thomas Brown]

who can talk more trash?

SO Original Poster:

SEE WHAT YOU HAVE DONE!!!! :D

Now these guys are circling the tree to pee over the last pee spot. AND it is a PINE tree! :D (that was not a jab at you Ms. Aturn)

Zilch thank you in correcting my "hear" vs. "listen". I had them bass-ackwards. (see, I learned something today)

Once again back to our scheduled "you said this, no you said this programing"

[Thomas Brown]

Re: Flat Response

That's where you have to start using your ears.

are those the squishy things, that constantly ring, on both sides of the lump thats 2 feet above my arse? :p

[Dennis H]

Re: Flat Response

[But we can still fight about directivity, no...? ;) ]

Hey! My directivity can beat up your directivity, pal!

(He says while listening to and thoroughly enjoying Eric Clapton and B.B. King playing on Pandora through a couple of cheapo Yamaha computer speakers.)

[Deward Hastings]

Re: Flat Response

Very desirable, perhaps, but the "P" version might reasonably be viewed as what engineering considered an optimum compromise for us cheapskates wanting to sit up front....

"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 . . .

[Deward Hastings]

Re: Flat Response

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)
Downward tilted in-room response
Smooth response curve on-axis
Smooth response curve in-room
Extended bass response

If we could that would be the end of "constant directivity", since it doesn't make possible "flat on-axis" and "downward tilted power" at the same time.

The question yet to be answered by "constant directivity" proponents is how to deal with the resulting "flat" power response. SL's (current) proposal of a global "downward tilt" (both on-axis and power) is a possible solution that clearly has some people "in a twist". I haven't seen their plausable alternative . . . their response often seems to be "flat-flat is fine, pay no attention to what you hear . . .".

As for "Smooth response curve in-room" . . . that's also at least somewhat in contention, as it is SL's assertion that we are, at least to some extent, able to "tune out" the room response, at least for familiar sounds. If we are listening for the "original sound" our mind seems to be able to ignore at least some "known" room response issues. I have this experience when we play in different halls . . . I can "hear" the hall, but I can also filter the hall (in my head) and "hear" the band. Musicians will consistently talk about the intonation of a particular player heard on what we all acknowledge to be terrible recordings . . . somehow they listen past the defects. We all do it to some extent when listening to speakers, and it can compromise our judgment unless exceptional care is taken . . .

[Zilch]

Re: Flat Response

To those firmly entrenched in the "concert hall realism" tradition, rolled-off highs would be an essential element of optimum performance, but for us headbangers, not so much. It's about demographics, in large part, but I'm getting ahead of myself here, telegraphing a thesis. :rolleyes:

If we could that would be the end of "constant directivity", since it doesn't make possible "flat on-axis" and "downward tilted power" at the same time.

In theory only, as, in practice, it doesn't exist. Geddes advocates imperfect constant directivity so that image stabilization deployments may be practiced, but by another view, that's merely rationalization of the actual performance of his waveguides, consistent with the presence of linear distortion in their on-axis response. Also, as I earlier stated, there is recognition among proponents such as both Linkwitz and Geddes that with "better" constancy comes the potential necessity of adjusting the axial response to achieve a desired in-room response characteristic.

There is no conflict here -- these are design tools in pursuit of an optimum balance, but clearly, constant directivity and uniform power response favor influence of the loudspeaker over that of the room, and the prospect, at least, of order in lieu of chaos....

[Dennis H]

Re: Flat Response

If we could that would be the end of "constant directivity", since it doesn't make possible "flat on-axis" and "downward tilted power" at the same time.

Not really. Even without specialized 'room treatments,' most people have carpets, drapes, overstuffed couches, etc., that tend to absorb more highs than lows.

[ligs]

Re: Flat Response

Not really. Even without specialized 'room treatments,' most people have carpets, drapes, overstuffed couches, etc., that tend to absorb more highs than lows.

I wonder if it is the time to do "live vs recorded music" demonstrations again, now that we have speakers much more refined than AR 3a of of 60's. From what I read about these events, people were fooled into believing they were listening to live music in stead of speakers!

[Dennis H]

Re: Flat Response

I wonder if it is the time to do "live vs recorded music" demostrations again, now that we have speakers much more refined than AR 3a of of 60's. From what I read about these events, people were fooled into believing they were listening to live music in stead of speakers!

That's how Linkwitz voices his speakers. He records a concert with mics on his eyeglasses and then goes home to see (hear) how close the playback is to what he remembers.

[Deward Hastings]

Re: Flat Response

Even without specialized 'room treatments,' most people have carpets, drapes, overstuffed couches, etc., that tend to absorb more highs than lows.

Rarely enough more. The room is, of course, always *part* of the equation, but it's a mixed bag. I don't get as much of the oft-noted "bloom" around 2kHz from the ORION tweeters because the walls to either side of the speakers are quite "dead" in that range in my room (still get the extra bounce from the floor and ceiling, though). So "correction" in the crossover could potentially overcorrect, in my particular situation. The question becomes one of *where* we apply the corrections . . . room treatment, equalization, the speaker itself . . . and how to accomodate for different applications of a particular design (those switches on the back of a 2030A are an example of one approach).

And there's still the problem of wide variation in recordings . . .

[ligs]

Re: Flat Response

That's how Linkwitz voices his speakers. He records a concert with mics on his eyeglasses and then goes home to see (hear) how close the playback is to what he remembers.

Would it be ideal to voice your speaker against live music in situ in real time! We have a poor recall of sound unless it is side by side. Luckily our recall of taste is much better

[Zilch]

Re: Flat Response

Not really. Even without specialized 'room treatments,' most people have carpets, drapes, overstuffed couches, etc., that tend to absorb more highs than lows.

We also have the significant variable of pattern width, and how that "plays" in-room.

I wonder if it is the time to do "live vs recorded music" demonstrations again, now that we have speakers much more refined than AR 3a of of 60's. From what I read about these events, people were fooled into believing they were listening to live music in stead of speakers!

They were, uhmm, "contrived." Edison did the same thing, with much the same result, in 1906.... :rolleyes:

[Deward Hastings]

Re: Flat Response

They were, uhmm, "contrived."

I wasn't there to hear them, but my understanding from people who were is that the most effective was an anechoically recorded cello played back on stage next to a live cello. Similar radiation pattern, same reverberant hall effects, I can almost believe that particular example could work.

[DDF]

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)
Downward tilted in-room response
Smooth response curve on-axis
Smooth response curve in-room
Extended bass response

Now, if you don't have all of those, you may need to compromise one to make one or more of the others better. That's where you have to start using your ears.

Dennis,
Count me as one dissenting opinion as stated here, which I'll come back to again:

http://techtalk.parts-express.com/showpost.php?p=1665638&postcount=4

I think you always need to deviate from flat precisely because you can't achieve perfection in the other areas. I raised a few other scenarios in the post linked, where deviation from flat is warranted.

BTW, did Harmon ever publish the acoustic characteristics of their listening room that you referenced earlier? There is an IEC spec already for a typical listening room, I'm curious to see how they improved it. I built an IEC room once, it didn't sound that great!

I'm really enjoying the topic of this thread, when it doesn't veer into the weeds. Lets please keep it civil and focussed guys! 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!

[DDF]

Re: Flat Response

I wasn't there to hear them, but my understanding from people who were is that the most effective was an anechoically recorded cello played back on stage next to a live cello. Similar radiation pattern, same reverberant hall effects, I can almost believe that particular example could work.

Sounds about right.

For an incredible demonstration of how dry a living room sounds, Denon recorded a symphony in an anechoic chamber. It's so dry, it feels like your ears are being sucked from your head, and my room is "wet".

http://www.amazon.com/Denon-Hi-Fi-Wolfgang-Amadeus-Mozart/dp/B0000034M9