Can Objective Loudspeaker Measurements Predict Subjective Preferences?

[edgewound]

A speaker system can measure flat from DC to light, yet still sound different based on the physical design, driver types and sizes, horn loaded or direct radiator, compression drivers vs cones and domes, crossover design slopes and filter types chosen.

Not only that, the physiology of the listener is also taken into account. Harman voices their speaker systems to appeal to a certain market. Case in point...The JBL Everest II was required to be a three way speaker to appeal to the Asian market regardless if it sounded the same as a two way or a three way. The 045Be supertweeter rolls in at 20KHz. Cover up the tweeter and it sounds no different, because the 476Be compression driver was flat to 40Khz. Greg Timbers told me this at CES when the Everest II made it's debut.

So...I said "No".

 

[Pogre]

I don't think some are understanding the question. If you show me measurements of speakers and one is relatively neutral and the other is a complete mess I think anyone can tell which one would be subjectively preferred just looking at the chart.

 

[Mikado463]

I don't think some are understanding the question. If you show me measurements of speakers and one is relatively neutral and the other is a complete mess I think anyone can tell which one would be subjectively preferred just looking at the chart.

agreed, but any speaker that's a 'complete mess' I wouldn't waste my listening time with.

 

[Pogre]

agreed, but any speaker that's a 'complete mess' I wouldn't waste my listening time with.

I'd say an objective measurement could tell you a speaker is a mess before even listening to it.

 

[Mikado463]

I'd say an objective measurement could tell you a speaker is a mess before even listening to it.

yes and thus my example of Wilson speakers, though I wouldn't call them a 'mess' !

 

[edgewound]

From...in my opinion...the premier loudspeaker designer in existence gives his summation.

"...we like different errors..."

 

[Pogre]

From...in my opinion...the premier loudspeaker designer in existence gives his summation.

"...we like different errors..."

Yup. And accurate measurements can identify which of those errors any one person may prefer.

 

[edgewound]

Yup. And accurate measurements can identify which of those errors any one person may prefer.

I happen to prefer the errors that Andrew prefers. He doesn't design speakers by committee...he simply has good taste in sound reproduction.

 

[Jerkface]

I mean, the end goal for audiophiles is faithful reproduction of the source, right? That's literally why we spend gobs of money on this equipment, isn't it?

Except...

Half of us have shitty listening rooms full of nulls and lacking acoustic treatments entirely. Even a pair of low-end Vegas can sound great in a well-treated room. But it's not as impressive as $20K worth of speakers and a $50K integrated amp, is it?

So how much of it is lord helmet-swinging versus an actual desire for truly great audio?

I'm a musician, and my end goal has always been a system that faithfully reproduces sources. But I've noticed a subtle problem with this philosophy - badly recorded source material sounds really, really, really bad on a great system. Because all the flaws are right there, in your face. Hell, I totally hate the record my band released two years ago because of all the problems I hear in it now that I have a system that reveals all those problems. *cringe*

So what is the point, other than maximally enjoying the music you love? If you're into music that happens to be extremely well-recorded, perfectly performed, deep, and detailed, then yes, faithful reproduction is the ideal. Otherwise, it's completely subjective, because your source material will sound better/worse depending on the system you choose, right?

In the end, I didn't answer the poll because of the above conundrum.

 

[Jerkface]

PS: I love, love, love that they substituted "Lord Helmet" for what I typed there.

 

[ASCTim]

I take great pride in having indirectly contributed to some really fine loudspeakers, some of them very affordable, from our own company and from several non Harman companies. The knowledge is there for all to benefit from.

Thank you! I've been heeding that shared knowledge and it's really worked a treat for my DIY horns. It's funny I've known about the importance of smooth off axis response long before I got involved in a team project to build some big horns. My project partner and I disagreed about the importance of dispersion characteristics vs efficient horn loading. Out of curiosity I went along with his thinking and so I got to try to make a horn system with poor off axis response sound good in a home environment. I couldn't do it to my satisfaction. Fortunately, excellent waveguides are readily available at very affordable prices so I was able to go from disappointed to highly gratified for an extra $100 and a bit of experimenting with the crossover settings.

 

[3db]

Dr Toole, I just picked up the 3rd edition of your book Sound Reproduction and I learned in your introduction that you are a Maritimer like me and born in the same city as me. Very cool I think. I dont know if you remember the old Gunningsville bridge that connected Moncton and Riverview? My dad flew under that bridge on low tide back in the early 50s and is considered a legend in the Moncton Flying Club.

 

[Cask05]

...my end goal has always been a system that faithfully reproduces sources. But I've noticed a subtle problem with this philosophy - badly recorded source material sounds really, really, really bad on a great system. Because all the flaws are right there, in your face.

The alternative is to simply fix your bad recordings. I've done it for about 19K tracks thus far over the past 6+ years and I find this method works a lot better than trying to buy or build a bad hi-fi system to play those multitude of badly mastered tracks. Since I was a little kid, I could hear these badly done music tracks, and I didn't play them nearly as much because of this fact.

When I finally found Audacity and had already set up my system to be a neutral hi-fi reproducer, all those problems that you speak of simply disappeared. It was a great catharsis to finally be able to fix the most egregious mastering problems at their source (usually the mastering EQ used...but not entirely). I found that virtually every popular music track, including rock and all its multitude of derivative genres, has its own unique problem which was introduced during mastering to make them sound "more commercial" for the mass market--which includes a lot of really bad earbuds and cheap loudspeakers. Once this is largely undone, real gems are found. I play those once badly done tracks quite often now.

It's funny I've known about the importance of smooth off axis response long before I got involved in a team project to build some big horns. My project partner and I disagreed about the importance of dispersion characteristics vs efficient horn loading.

This is something that is like the current rage of nostalgia: bad horn design based on the mistaken notion that maximum on-axis efficiency at low frequencies is the goal (i.e., its the implied or stated requirement that's wrong). Because of that mistaken notion still being held by so many horn loudspeaker enthusiasts, we still have a great many badly performing horn profiles in service. The further back in time you go, the worse the horns get in this regard.

I've found that there are extremely few horn designs that are truly good performers--and that includes many horns being sold today as "waveguides". I do recommend the pyramid-shaped straight-sided horns with tractrix flare mouths (inaccurately called "conical horns"...which implies a single area expansion formula which is typically never used) and without throat slots as the best of the horn designs.

Chris

 

[ASCTim]

This is something that is like the current rage of nostalgia: bad horn design based on the mistaken notion that maximum on-axis efficiency at low frequencies is the goal (i.e., its the implied or stated requirement that's wrong). Because of that mistaken notion still being held by so many horn loudspeaker enthusiasts, we still have a great many badly performing horn profiles in service. The further back in time you go, the worse the horns get in this regard.

I've found that there are extremely few horn designs that are truly good performers--and that includes many horns being sold today as "waveguides". I do recommend the pyramid-shaped straight-sided horns with tractrix flare mouths (inaccurately called "conical horns"...which implies a single area expansion formula which is typically never used) and without throat slots as the best of the horn designs.

Chris

Thanks for the response. Maybe a pyramid shaped straight sided horn with a tractrix flare mouth will be my next project. Are you saying that this wouldn't qualify as a true conical because the mouth flare is tractrix? In other words, a true conical cannot have any kind of round over, just has to hard terminate like the Oswalds Mill horns?

 

[Cask05]

...Are you saying that this wouldn't qualify as a true conical because the mouth flare is tractrix?...

The straight-sided portion of the horn is almost never a straight x^2 area expansion ratio ("x" being the distance along the centerline of the horn). That's the reason why you really can't call them conical.

A tractrix mouth flare is actually a bit more efficient vs. horn length than other curved mouth profiles in terms of holding polar control to lower frequencies.

Chris

 

[ASCTim]

The straight-sided portion of the horn is almost never a straight x^2 area expansion ratio ("x" being the distance along the centerline of the horn). That's the reason why you really can't call them conical.



Chris

If the sides are really straight it seems the x^2 expansion ratio is unavoidable. Am I missing something?

 

[Cask05]

Am I missing something?

Yes, polynomial expansion.

 

[ASCTim]

Yes, polynomial expansion.

I'm having trouble imagining any straight sided horn that doesn't adhere to the x^2 expansion ratio. Can you give me an example of one that doesn't?

 

[Cask05]

A quadratic area horn expansion formula is not a "conic" area expansion equation (i.e., x^2).

For instance:

y = 4.25x^2 + 210x + 2575

The formula is in mm^2 referenced from the throat entrance. This is a measured area expansion profile for the straight section of a well-known commercially produced horn.

Chris

 

[ASCTim]

I think I understand. As long as the cross sectional shape remains proportionally the same, such as a square, it will meet the strict definition of a conical flare. But if it gets wider faster than it gets taller like so many horns do it cannot.