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Evidence-based Speaker Designs

jhaider

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The 10kHz null is a reflection off the tweeter-midbass transition, the Kali IN-8 has it too, as do pretty much every coax except Genelec , TAD, Technics and KEF. It fills in in the listening window so I'm not that worried about it. Amir's measurements of the IN-8 show that.

TAD definitely has it, too. You can see it in JA's terrible normalized horizontal off-axis plots in Stereophile:

Pioneer S-1EX
307P1Xfig5.jpg


TAD Evolution One (de facto successor to above speaker)
713TAD1fig5.jpg


Not as pronounced on Micro Evolution One because the coax is smaller:
218TADfig6.jpg
 
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Ilkless

Ilkless

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TAD definitely has it, too. You can see it in JA's terrible normalized horizontal off-axis plots in Stereophile:

Pioneer S-1EX


TAD Evolution One (de facto successor to above speaker)


Not as pronounced on Micro Evolution One because the coax is smaller:

Thanks. It looks about slightly worse than the Technics one, which only has a major null right at the edge of audibility.



My frame of reference though for really bad 10kHz nulls are the speakers with SEAS OEM coaxs, such as the Trenner and Friedl Sun - this was what I was comparing to in saying that 10kHz null is not that bad on TADs (a comment that JA made in Stereophile as well):

1582152682322.png


FWIW though I would take a very high-Q null over many small nulls and an inconsistent off-axis.
 

jhaider

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Thanks. It looks about slightly worse than the Technics one, which only has a major null right at the edge of audibility.

Practically I think these effects are audibly inconsequential, as offensive to the eye as they may be.

I've been enjoying Pioneer EX speakers for years. The direct axis from all three speakers crosses ahead and above the money seat.

I've had various speakers in our living room for review. However, the only thing I've preferred on balance are the two JBL 7-series monitors.
 

tuga

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What does "Evidence-based Speaker Designs" means?

Evidence of what?
 

MZKM

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What does "Evidence-based Speaker Designs" means?

Evidence of what?
High preference in double-blind listening sessions.
Basically, designing speakers based on science, not what the designer personally feels (cough super adamant about 1st order crossovers cough)

Some speaker designers don’t even do measurements in the designing phase; J.A. gave a talk at RMAF and one example speaker had a super odd response, it was because the crossover design was so poor the drivers were out of-phase, and the woofer was crossed too high so it was distorting, but the designer thought that it was a tweeter issue and lowered the upper treble, so now it has three problems instead of 2.
 
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tuga

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High preference in double-blind listening sessions.
Basically, designing speakers based on science, not what the designer personally feels (cough super adamant about 1st order crossovers cough)

Some speaker designers don’t even do measurements in the designing phase; J.A. gave a talk at RMAF and one example speaker had a super odd response, it was because the crossover design was so poor the drivers were out of-phase, and the woofer was crossed too high so it was distorting, but the designer thought that it was a tweeter issue and lowered the upper treble, so now it has three problems instead of 2.

I see, so it means higher-fidelity designs.


I find the "High preference in double-blind listening sessions" a bit biased.
 

q3cpma

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thewas

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Just posting one measurement in some "regular room" is far from an evidence-based speaker design and the knowledge we have nowadays of what makes loudspeakers sound correct and being preferred. In the 70s there were some more brands that made loudspeakers with similar designs and it was already then soon obvious that its just one approach but in most cases not an optimum one.
 

q3cpma

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Just posting one measurement in some "regular room" is far from an evidence-based speaker design and the knowledge we have nowadays of what makes loudspeakers sound correct and being preferred. In the 70s there were some more brands that made loudspeakers with similar designs and it was already then soon obvious that its just one approach but in most cases not an optimum one.
Well, I agree that FR alone isn't enough, but since it's supposed to be omni...
 
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pozz

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I see, so it means higher-fidelity designs.

I find the "High preference in double-blind listening sessions" a bit biased.
Not higher fidelity according to the designer's wish to follow this or that path, but according to published research. I doubt you would find double blind testing biased if you dug in to the literature somewhat. That's just one aspect of the whole, though.
 

tuga

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Not higher fidelity according to the designer's wish to follow this or that path, but according to published research. I doubt you would find double blind testing biased if you dug in to the literature somewhat. That's just one aspect of the whole, though.

What I find biased is not the double blind testing (that's the science part of it) but the reasoning behind this listener preference survey since listener preference may or may not equate to accuracy depending on many factors including the listener. In fact, many audiophiles tend to prefer some kind of "presentation" (equipment with euphonic or other types of distortion).

But I understand that average listener preference may be important for manufacturers for commercial reasons.
 

q3cpma

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What I find biased is not the double blind testing (that's the science part of it) but the reasoning behind this listener preference survey since listener preference may or may not equate to accuracy depending on many factors including the listener. In fact, many audiophiles tend to prefer some kind of "presentation" (equipment with euphonic or other types of distortion).

But I understand that average listener preference may be important for manufacturers for commercial reasons.
How many actually prefer it? Look at headphone amplifiers with decorative tubes; they "sound" warmer to audiophiles.
 

pozz

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What I find biased is not the double blind testing (that's the science part of it) but the reasoning behind this listener preference survey since listener preference may or may not equate to accuracy depending on many factors including the listener. In fact, many audiophiles tend to prefer some kind of "presentation" (equipment with euphonic or other types of distortion).

But I understand that average listener preference may be important for manufacturers for commercial reasons.
I understand your reasoning but the research shows otherwise. Under DBT conditions, listeners tend to prefer the same thing, and fail to notice distortion (unless high level or high order, which is typically not the case in popular boutique gear or speakers).

Edit: By "the same thing", I meant that their preferences tend to converge, not diverge, and that this remains consistent across ages, genders and cultural backgrounds. This research is the basis for the spinorama curves and measurement techniques that are used to assess speakers here.
 
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napilopez

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11247200_800.jpg

While browsing Thomann, I saw https://www.thomann.de/fr/teenage_engineering_od_11.htm which seems to have an interesting design:
https://teenage.engineering/products/od-11/technology
https://teenage.engineering/products/od-11/carlssonstory

That's perhaps the only smart speaker I would recommend, even if the website clearly designed as an Instagram sissy trap made me spend some willpower to read on.

That looks pretty good! In the smart speaker world, I keep being impressed the Sonos Move. It's hard to interpret my quasi-anechoic measurements of it given it's a "quasi omni" speaker with a really weird waveguide but I was actually most impressed by the in-room response. Even being a non-averaged measurement showing room artefacts, it's notable how timbrally balanced the in-room curve is. This graph was meant to show SPL compression but it also shows the in-room response.

o9KlFK3 (2).png


(Not sure why the graph limits are 34Hz to 18kHz). Other than the room nulls in the bass and general in-room measurement messiness, this basically just looks exactly like the Harman target curve for the PIR lol.

What I find biased is not the double blind testing (that's the science part of it) but the reasoning behind this listener preference survey since listener preference may or may not equate to accuracy depending on many factors including the listener. In fact, many audiophiles tend to prefer some kind of "presentation" (equipment with euphonic or other types of distortion).

But I understand that average listener preference may be important for manufacturers for commercial reasons.

This has actually been debunked though. See this chart:

Harman Trained vs Untrained.png


Various different types of listeners all chose nearly the same order of preference for speakers. Note there's a group in there for reviewers =] (I'm one of them!)

By the way, this doesn't mean people don't still have preferences. It's just we are more similar in our tastes than we tend to assume. Speakers can be evidence based and still sound very different. A competently designed omni will sound very different from a competently designed constant directivity design or a good array speaker.
 

bobbooo

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Changelog
28/2/19 -
Placed HEDD entry on main list.
6/2/19 - Expanded the Danley entry and placed it in the main list.
2/2/19 - Expanded the Keele/Dayton CBT entry and placed it in the main list.
27/1/19 - Expanded the NHT, Technics SB-C700, KS Digital and Arendal entries. Added the Gradient Audio Finland entry into the main list.
___________________________________--
There is a "State-of-the-art Loudspeakers" thread on this forum already. A slight semantic distinction from that thread and my intention here has to be made from the outset. The focus is not on absolute pinnacle performance from cost-no-object speakers. Instead, I hope to share about more affordable loudspeaker designs and manufacturers that have a demonstrable commitment to releasing evidence-based designs consistent with acoustical physics and psychoacoustics, even if they do not quite reach the levels of unsurpassed excellence often appearing in that other thread. There is a surprising variety of driver configurations and design choices in the list that follows - much more so than proponents of subjective intuition-led audio reproduction often assert when they speak of a "boring" homogeneity/convergence arising from evidence-based audio.

However, the nature of divergence in the loudspeakers I describe here is, in my view, consistent with what one might call a "reasonable pluralism". I will attempt to point out the different priorities of each design and the relative compromises their designers accept. However, what all these designs share is a spirit of progressiveness, advancement and commitment to making rationally-defensible engineering choices - and are most importantly well-priced. From my perspective, it is actually the conventional "hifi" market that is far more homogeneous in its stagnation of design format - think passive flat-baffle "monkey coffins" without any care to match dispersion.

Note: the list is unsorted, work-in-progress (hence the empty entries) and largely stream-of-consciousness for now. If this thread gains traction, I will probably reformat it with a taxonomy based on driver configuration (2-way, 3-way, coaxial etc.) and expand my descriptions. At least one speaker in every listed manufacturer's line has been independently tested to measure well. Special mention has to be given to German magazine Sound and Recording for world-class measurements for several speakers. They deserve all the support we can give for their contributions. You can do so by purchasing a PDF collating measurements of over 80 speakers (mostly active monitors). You can read more about their measurements in this thread.

Neumann - The German studio legend, now under Sennheiser, has a line of active monitors that have impeccable horizontal dispersion (note: refraining from using the more technical term "directivity" in the interests of making this piece accessible). The designs show a clear lineage tracing back to manufacturer Klein+Hummel, which Sennheiser bought over, rebranding their loudspeakers as Neumann products and releasing new designs under the Neumann name. There is existing material on ASR about the importance of at least smooth horizontal dispersion for accurate (and likely preferable) playback from Toole et al.

The Neumanns are perhaps some of the most conventional speakers you will see in this thread. The entire line uses the multi-way non-coaxial driver configuration that dominates audio. However, they use computationally-optimised waveguides (see here for explanation on what a waveguide is, as well as the importance of seamless horizontal dispersion at least) to ensure a seamless transition in dispersion. Tools like computational fluid dynamics have been used to minimise any sort of anomalous movement of air (think port chuffing and baffle diffraction) within the physical limits intrinsic to the size of each speaker. This explains the complex port shapes and seamless baffles (either cast aluminium or polycarbonate) with no edges. Incredibly advanced construction techniques compared to boring old veneered MDF boxes. All their speakers are excellent, but it is the two babies in the line - the KH80DSP and KH120A - that are conspicuous value leaders for their performance level. The KH80DSP is the latest design. It uses a DSP crossover. It has a 4-inch midwoofer, which basically restricts it to very nearfield or desktop use. However, it is perhaps at the absolute limit of loudspeaker engineering for its size. This is a speaker, that when tested independently at a German acoustics lab, achieves a +/-0.6 dB (you read that right) on-axis response out of the box (scroll down for measurements). It is flat to 60Hz and has a -6dB point at 52Hz - great for the size. Distortion is state-of-the-art, which allows maximum SPL to be above 90dB right down to 60Hz. It has linear phase response even at crossover due to the use of FIR filtering. The crossover works in tandem with the waveguide to achieve absolute seamless and uniform horizontal dispersion. It has vertical dispersion as good as possible for a non-coaxial, non-symmetrical driver placement (aided no doubt by tight centre-to-centre spacing made possible with the tiny woofer). All that for $1000 a pair. It is pricey, but (in my reckoning) commensurate with the amount of R&D. Did I mention the hiss (always a complaint against active monitors) of the KH80DSP is not just inaudible in the typical sense of being masked by room noise? No, it was tested at 0dbA/1m - just about the absolute threshold of human hearing acuity under any circumstances. The KH80 upstages its older, larger brother, the KH120A, which is designed similarly (and measures quite similarly), but is "only" +/-1.2dB on-axis, has a bit more vertical lobing due to the larger midbass driver, uses an analog active crossover and doesn't have FIR filtering. Still a very good value as I've outlined. Hopefully a KH120DSP is in the works.

Genelec - A famous name. Much of their product line is like Neumann's. Smooth, seamless low-diffraction enclosures, smooth dispersion for their non-coaxial loudspeaker designs. Neumann is slightly more accurate. Genelec is sold in more places. Here are polar maps of the most common 2-way Genelecs (provided by the company) compared to the Kali LP-6. However, they have released 'The Ones' - comprising the 8331A, 8341A and 8351A in order of size. This uses coaxial driver loaded in a large waveguide, crossed to double oval-shaped woofers that fire out of slots made by the large waveguide and the rest of the cabinet. There is no baffle in the conventional sense to speak of. The entire front of the speaker is a waveguide. Sound and Recording has measured the 8331A and 8351A. At the bottom of this post, I explain the advantages and disadvantages (have edited it from the original for clarity):



Kali - I don't need to introduce them, there is a thread on this forum already. Their story (top designer, blank slate, budget positioning) is well-known, the design well-optimised for its constraints. I have heard reports of both hiss and no hiss. But the acoustic radiation of the speakers is otherwise beyond any reproach for the price and even much more (see my link early in the post about waveguides and dispersion to understand how to read a polar map). There are some minor response anomalies to consider though, like a slightly-depressed treble.

KS Digital - A highly under-the-radar active monitor manufacturer outside of Germany. Their speakers tick a lot of boxes. Coaxial. Sealed. Active DSP with class AB amplifiers. FIR filtering for linear phase at crossover. Aluminium enclosures (with hardwood trim). German-made even. All that for around KEF LS50 passive pricing. Scarcely believable, right? The model I'm referring to, the C5 Reference, uses a 6.5-inch SEAS Prestige coaxial driver imported from Norway. This entry is special, because it is the C5 Reference inspired this thread. Sound and Recording measurements here.

It has some issues but there is, as I wrote, a broader significance to this product:



KSD also has a newer line that load the coaxial tweeter in a rigid waveguide, reminiscent of Presonus and the old Altec coaxials. I have not seen detailed measurements or indeed much information at all about it.

NHT - I think their fairly long history means they should really be in the "usual suspects" section below. However, the brand was in the woods for a short span in the 2000s, before re-emerging with a direct-sale model. They also seem to have a mediocre reputation among pure subjective audiophiles for their ho-hum Chinese OEM provenance, nondescript aesthetic and association with home theatre (all of which do not predict any acoustic property of their speaker design).

Their speakers are highly well-designed across the entire line and (in a welcome departure) sealed. The idea of a well-engineered flat-baffle 3-way is to offer near-seamless dispersion wider than a waveguide speaker. Waveguides narrow dispersion to help achieve a seamless transition between drivers with a large disparity in radiating diameter. The larger driver's dispersion gradually narrows with higher frequency (and shorter wavelength). Sound path length differences between different points of the radiating surface at HF become significant relative to the wavelength of the frequencies in question.

This necessarily entails acoustic interference (due to the addition and subtraction of out-of-phase signals) that accumulate into highly-attenuated SPL at oblique angles compared to on-axis - ie. a narrowing of the net acoustic radiation a.k.a dispersion with increasing frequency. A flat-baffle 3-way with carefully chosen driver diameters splits the difference so the dispersion mismatch is small enough to be almost eliminated (at least on the horizontal plane of the design axis) through optimising driver placement and crossover topology. This is evident in the NHT C3, as well as the Philharmonic BMR.

What of flat-baffle 2-ways? The mismatch in dispersion is very large, and minimising it requires crossing tweeters lower and woofers higher than they'd be comfortable with in virtually all circumstances.

Arendal Sound - Another direct-sale Scandinavian brand, but Arendal hails from Norway instead of Sweden like XTZ. They sell a line of high-SPL speakers, . They provide on-axis and off-axis curves as well as impedance response. Drivers are integrated well with a deep waveguide and good crossover. That sort of waveguide promises narrower dispersion but higher SPL capability (together with what look like beefy woofers), which is good perhaps for rooms with harsh specular early reflections from sidewalls. Unfortunately we don't know what smoothing technique they used for the curve, but the graphs don't seem excessively-smoothed.

Technics - The venerable brand's return to high-performance audio was muted, not least because What Hi-Fi gave a two-star review for their coaxial SB-C700 that has no basis in empirical reality. I will not dignify that site with a direct link on my pose. Stereophile measured them. These are way better designed than the LS50 passive. LS50 has shelved up response (+3dB within the listening window per NRC measurements at Soundstage Network) from 2-5kHz. That's stupidly bright. Its the result of a dispersion mismatch at the crossover frequency - rather ironic because coaxials provide a better basis for smooth-dispersing speakers to be engineered. In contrast, the SB-C700 is totally seamless in dispersion and flat throughout the crossover range. Going by raw driver performance, the Technics is only very slightly behind the Genelec seamless coaxial that covers the midrange up and the KEF Uni-Q. As a complete speaker, the SB-C700 leaves the LS50 (and the other 2-way KEF coaxs without a separate woofer) in the dust. In fact it is to my knowledge, the best implementation of a pure 2-way coaxial, despite using a passive crossover. It extends cleanly (see distortion measurements in the third pic of the first post) right down to its 48Hz tuning frequency, giving up little in bass performance to a non-coaxial midwoofer of similar size.

The "peaks and dips" are mostly artifacts of the normalisation technique as mentioned in the KS Digital entry. Also the midwoofers are much larger (6.5-inch vs 5.25 for LS50), which means more headroom and bass extension. In my opinion their white low-diffraction curved enclosures and flat aluminium honeycomb midwoofer look a damn sight better than the LS50's industrial design too.

Gradient Audio Finland - Read up on Jorma Salmi's contributions to audio engineering, talking about his wide-ranging research publications would be beyond the scope of this thread. Suffice to say he, like Siegfried Linkwitz, was concerned about room-agnostic performance and optimising designs using both in-room measurements and a solid foundation in engineering. To this end, Gradient's top offerings are dedicated to exotic driver configurations that achieve unconventional polar patterns like cardioid, dipole or a mix of both. All their speakers are built in Finland using birch ply. Their entry-level offerings are the Gradient Five standmount and Gradient Six standmount, both of which using SEAS coaxials customised to their specs and passive radiator bass loading. I have no measurements and only an useless subjective report that they did not sound severely coloured in my experience and were enjoyable on and off-axis. Their flagship, the Revolution mixes cardioid (in the midrange below baffle step), dipolar (in the bass) and monopolar (in the treble) radiation. They use dual 12-inch woofers mated to a coaxial acting as MF/HF. The 1997 version of the speaker is exemplary for its era and still good by today's standards. It has been incrementally-revised to keep up with driver and active crossover advances of course. The Revolution now is not that of 1997. The Five and Six use the same coaxial as the current Revolution, except those are used "full-range".

Note that even way back then, the custom coaxial they specced does not have any major on-axis dips below 10kHz, and only one at 16kHz, which is more than can be said for some coaxial drivers today (not that it should be a problem IF it fills in immediately off-axis). The in-room response John Atkinson measured falls within +/-1.3dB at 1/3-octave, one of the best results Atkinson ever measured. Robert E. Greene of The Absolute Sound reports similarly in his own room.

Constant Beamwidth Transducers (Dayton/DB Keele) - There are two CBTs you can buy as manufactured products: the CBT36 kit and the CBT24 kit/complete speaker, both offered by Dayton. The CBT24 is on sale for $1495/pr as of February 2, 2019. For mini-monitor money, you can get a bleeding-edge driver array, albeit limited by driver performance. I would personally love to see someone stick in Vifa TG9s or some other widebander with smoother dispersion and FR. Rick Craig of Selah Audio also does custom CBT work at a much higher price range. The CBT isn't a line array. Despite its looks it is as far as one can get from a line source. The curvature and gradually-decreasing SPL (called "shading") emitted by drivers as one moves up the array come together - as someone described brilliantly on DIYAudio - a "slice" (like an orange) of the wavefront of a perfect point source placed on the ground plane. Project an imaginary line backwards from each driver at the angle at which the driver is pivoted. Do you see the slice of a sphere now? Exceptionally uniform coverage both vertically and horizontally. No floor bounce because the speaker is on the ground plane. Floyd Toole mused that it could be the "perfect" surround loudspeaker due to the uniformity of coverage allowing similar sound over a larger seating area. There is more discussion on another ASR thread.

Note that the CBTs will require subs and ideally DSP to equalise driver response. Don Keele (ex-JBL, designer of the JBL biradials before the CBT array for audio) has an excellent lecture series that examines the properties of CBTs:


Danley - Tom Danley was instrumental to popularising and improving the multiple-entry horn, through the Unity and Synergy horn designs. The designs allow point-source dispersion, without vertical lobing, yet also without the SPL limitations of direct-radiating coaxial drivers. Instead, Danley would load drivers, each firing from a different aperture along the sides of a horn with a single exit point. The spacing between apertures (and hence drivers that were mounted into it) were calculated to approach a quarter wavelength of the crossover frequency. This is to promote optimal driver summation, such that the wavefronts of drivers playing different frequency ranges (woofer, midrange and tweeter) do not destructively interfere with each other within the horn, and instead can be directed outwards smoothly, without major FR discontinuities. Anecdotally, the Synergy horns have drivers so well-integrated that one could stick their head into the horn and still not hear any significant interference between the drivers.

By optimising the driver configuration, crossover and placement, the Danley horns are coaxial, have immense SPL capability and offer very controlled directivity. Moreover the Synergy horns are linear-phase and have relatively flat frequency response. A critique of these horns (regardless of multiple-entry or otherwise) is the diffraction that they introduce due to their relatively sharp edges and straight sides, which have been maligned by researchers such as Earl Geddes as the source of the stereotypical horn "honk" (see page 8 onwards of the linked PDF), even if the FR does not seem to imply that much roughness or brightness.

The alternative per Geddes is a highly-contoured "waveguide" with a minimal amount of sharp edges that focuses purely on having smooth dispersion that gradually fades away outside of its optimal zone. In contrast, horns like the Synergy aim for a dispersion pattern with sharply-defined borders (because of the high-end sound reinforcement applications Danley had in mind, which require ensuring that the Synergies would have a sharply-defined guaranteed-linear coverage within a stipulated area for say, concerts). Think having a blurry, smooth border of constant width versus a border created with a sharp, straight line. A matter of priorities and reasonable tradeoffs between both methods, which captures the spirit of this thread. Here is a comprehensive video of the acoustics behind the Synergy design that might do better than words in explaining how much different it is from the typical loudspeaker we see:


HEDD - ADAM's co-founder starts a new firm. AMT active monitors, all assembled in Berlin (starting to see a German slant here...). More expensive than ADAMs of a similar design made offshore (T5V and T7V). Originally, the only third-party measurements I could find were from Russian sources with measuring conditions I'm not so sure of. I have since found a detailed teardown from Italy, which shows the HEDD Type 05 uses an asymmetric analog active crossover with 6th and 8th-order Butterworth crossover slopes. ICEPower modules (which have detailed AP measurements from B&O datasheets) are indeed used. The midwoofer is beefy too, with a cast frame. FR is fairly wavy, at +/- 2dB, despite the sophisticated crossover, but they have a DSP plugin (HEDD Lineariser) to linearise phase and FR. Arguably, its net effect is similar to that of a DSP crossover without incurring an AD/DA conversion should you be using a computer as source. The only thing this upstream DSP cannot correct is the narrow-band off-axis flare centred at 3.5kHz. Add-on support for either Ravenna or Dante is available through slot-in modules. Clever I think. Trivial to add a card if either protocol takes off, but one isn't left with a white elephant if it doesn't.

<<<<<<<<<<<<<<<<Entries below are work-in-progress>>>>>>>>>>>>>>>>>>>>>>>>>>>>



Merovinger - Custom installer from Germany with a DSP coaxial speaker using an air-motion transformer tweeter. I know the Fluid Audio FPX7 does so too, but the DSP for Merovinger seems more extensive. It is used to linearise both phase and FR, as well as time-align. Need to do more research on these. Intriguing.


ME Geithain - Coaxial, cardioid and active. From, you guessed it, Germany.

ABACUS Electronics - Germany again. Active speakers, preamps, power amps and streamers with built-in Acourate functionality.

The usual suspects (residual category for evidence-based brands that seem to be well-known, so I'll get to them last or simply leave this list unelaborated. Lots of information available from a Google search anyway) - Salk, Philharmonic, ELAC, Ascend, Selah, Seaton Sound, PSB, B&O, Revel, JBL (LSR and Synthesis), ADAM, Buchardt Audio, Vanatoo

Great list! I'd say Q Acoustics also deserve a mention - their lead acoustic engineer/designer, Karl-Heinz Fink of Fink Audio-Consulting has worked with a lot of big brands behind the scenes, and uses the Klippel Analyzer with the TRF (Transfer Function Measurement) and SCN (Scanning Vibrometer System) modules, as well as both anechoic and controllable echoic test rooms at their speaker test and development facility in Essen, Germany. Q Acoustics released a white paper that goes into some details on the engineering and has measurements of their recent Concept 500 floor-standing speaker, and independent professional measurements of their Concept 300 stand-mounted speaker by the Canadian National Research Council can be found here.
 

Rollomoto

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Well, it seems Q Acoustics/Mr Fink does not care much about directivity, as the symmetrical midwoofer<>tweeter<>midwoofer it flawed by design (as a 2-way, vertical lobbing). But instead they focus on cabinet and drivers, like most "high end" brands. That speaker might sound not bad, but I would not call that evidence-based design.
 

Frank Dernie

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Well, it seems Q Acoustics/Mr Fink does not care much about directivity, as the symmetrical midwoofer<>tweeter<>midwoofer it flawed by design (as a 2-way, vertical lobbing). But instead they focus on cabinet and drivers, like most "high end" brands. That speaker might sound not bad, but I would not call that evidence-based design.
They are just using additional evidence than just Harman's.
And using a broader array of evidence than just spinorama microphone measurements.
 

goldark

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Great list! I'd say Q Acoustics also deserve a mention - their lead acoustic engineer/designer, Karl-Heinz Fink of Fink Audio-Consulting has worked with a lot of big brands behind the scenes, and uses the Klippel Analyzer with the TRF (Transfer Function Measurement) and SCN (Scanning Vibrometer System) modules, as well as both anechoic and controllable echoic test rooms at their speaker test and development facility in Essen, Germany. Q Acoustics released a white paper that goes into some details on the engineering and has measurements of their recent Concept 500 floor-standing speaker, and independent professional measurements of their Concept 300 stand-mounted speaker by the Canadian National Research Council can be found here.

The 3020i also measures well in its price class: https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153
3050i https://www.soundstagenetwork.com/i...&catid=77:loudspeaker-measurements&Itemid=153

It's clear that Q Acoustics uses measurements/solid engineering when designing their speakers.
 

Igor Kirkwood

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The Salon2s are four-way systems; other options were three way. The differences are potentially better dispersion from the 3-inch midrange and the ability to play louder with less power compression - for movies, not music. As full range systems the Salon2s are fine for music. My multiple subs not only provide what I call "whole body" bass when needed, but employed in a Sound Field Management scheme they do it for multiple listeners - I rarely watch movies alone. But, as I said, once you have such a system one finds impressive examples of powerful low bass in modern recordings. Was it there deliberately? We may never know, because most recording studios, especially of the home variety, probably cannot reproduce those frequencies as I can.
Dr Toole you wrote "from the 3-inch midrange" for the loudspeaker Revel Salon Ultima 2.
It seems to be a 4-inch midrange, and not a 3-inch midrange ?
 
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