Introduction of Vera Audio Coherence 12 - a high quality speaker many can afford

[Matt_Holland]

This is a earlier prototype of the Coherence 12. Top driver was removable and many different ones were tested.

View attachment 459502

Especially with a smaller top driver or a coax, this is a speaker that would yield better directivity measurements than today's final Coherence 12 and perhaps get more praise from the community here.

However, the final Coherece 12 has taken an untraditonal approach where the result is a more even response when the speaker is placed in an actual room, and it sounds better in several areas despite that the directivity may not look as good as the former prototype. The latter depends on how a directivity plot is interpreted of course but with Spinorama and the traditional way of looking at the dispersion that is the case.

Do you plan to get them measured by Erin or Amir? Probably too big for the latter.

Besides the room response, what other measurements did you use to achieve the desired level of performance? Or put another way, what measurements do you think are the most important in determining subjective performance? The planar, for example, does that have a particularly clean waterfall decay? Is distortion lower than alternative drivers?

Thanks in advance.

 

[Bjorn]

Do you plan to get them measured by Erin or Amir? Probably too big for the latter.

Besides the room response, what other measurements did you use to achieve the desired level of performance? Or put another way, what measurements do you think are the most important in determining subjective performance? The planar, for example, does that have a particularly clean waterfall decay? Is distortion lower than alternative drivers?

Thanks in advance.

I'm going to conduct anechoic directivity measurements here in Norway first. Having accurate polars is obviously what matters and not who conducts the measurement. We'll see after that, but sending a pair to Erin is a possibility. Would be beneficial to combine it with a sale to a customer in the USA.

It's a combination of frequency response, directivity and how the speaker interacts with rooms and different positions, distortion, waterfall, diffraction, measurement of the reflex design, sensitivty, power handling, etc..
Both the distortion and the waterfall of the planar is very low and clean.

At the end though, listening is obviously crucial. The planar was a driver that came in late. I had decided on a different driver that kept the directivity higher in frequency. But the planar sounded cleaner, more open, gave a better illusion of instruments and vocal and also sounded smoother. To find out what that is I use different measurements techniques in variable acoustic environments. Since one is often comparing several differences (for instance directivity and distortion), one needs to try to isolate them.

 

[Matt_Holland]

I'm going to conduct anechoic directivity measurements here in Norway first. Having accurate polars is obviously what matters and not who conducts the measurement. We'll see after that, but sending a pair to Erin is a possibility. Would be beneficial to combine it with a sale to a customer in the USA.

It's a combination of frequency response, directivity and how the speaker interacts with rooms and different positions, distortion, waterfall, diffraction, measurement of the reflex design, sensitivty, power handling, etc..
Both the distortion and the waterfall of the planar is very low and clean.

At the end though, listening is obviously crucial. The planar was a driver that came in late. I had decided on a different driver that kept the directivity higher in frequency. But the planar sounded cleaner, more open, gave a better illusion of instruments and vocal and also sounded smoother. To find out what that is I use different measurements techniques in variable acoustic environments. Since one is often comparing several differences (for instance directivity and distortion), one needs to try to isolate them.

Thanks.
When comparing drivers did you build one of each and compare in mono?

 

[TimVG]

I'm going to conduct anechoic directivity measurements here in Norway first. Having accurate polars is obviously what matters and not who conducts the measurement. We'll see after that, but sending a pair to Erin is a possibility. Would be beneficial to combine it with a sale to a customer in the USA.

It's a combination of frequency response, directivity and how the speaker interacts with rooms and different positions, distortion, waterfall, diffraction, measurement of the reflex design, sensitivty, power handling, etc..
Both the distortion and the waterfall of the planar is very low and clean.

At the end though, listening is obviously crucial. The planar was a driver that came in late. I had decided on a different driver that kept the directivity higher in frequency. But the planar sounded cleaner, more open, gave a better illusion of instruments and vocal and also sounded smoother. To find out what that is I use different measurements techniques in variable acoustic environments. Since one is often comparing several differences (for instance directivity and distortion), one needs to try to isolate them.

I would understand if you'd rather not share too much details: but, I'll ask anyway: since you spoke in the past of time alignment - how do you go about that in relation to a design such as this. Is the acoustical axis (not necessarily listening axis) halfway between planar and woofer? Or the center of the planar? Just curious as in case of the latter, phase relationship would change with listening distance - although the low crossover certainly helps I believe.

 

[Bjorn]

Thanks.
When comparing drivers did you build one of each and compare in mono?

I had cabinets where the driver could be swapped. For comparisons, I probably use mono for about 90% of the listening. It goes faster to change the speaker position with mono, something which is important considering the audio memory. I know there are other theoretical benefits of mono as well, but some of those are less important when listening with acoustical treatment. I listen both with and without acoustical treatment in comparisons.

 

[Bjorn]

I would understand if you'd rather not share too much details: but, I'll ask anyway: since you spoke in the past of time alignment - how do you go about that in relation to a design such as this. Is the acoustical axis (not necessarily listening axis) halfway between planar and woofer? Or the center of the planar? Just curious as in case of the latter, phase relationship would change with listening distance - although the low crossover certainly helps I believe.

The listening height is used for time alignment. A FIR filter (linear phase) is used for crossover.

Also, the filters will be applied with different listening distances.

 

[Matt_Holland]

Commercial speaker builders sharing information about their design philosophies and design techniques is very much appreciated and enjoyably insightful!

 

[MenloBob]

These appear to have many of the advantages in directivity and crossover frequency of Jubilees, but in a much smaller package. If I recall correctly you experimented quite a bit with the K402 large format horn before finding other alternatives. Looks like that has paid off.

 

[Bjorn]

These appear to have many of the advantages in directivity and crossover frequency of Jubilees, but in a much smaller package. If I recall correctly you experimented quite a bit with the K402 large format horn before finding other alternatives. Looks like that has paid off.

Well, while there are some similarities there are also big differences. One similarity is that both have a low crossover.

The Klipsch Jubilee has a much narrower directivity. Approximately 90° horizontal beamwidth. The Coherence 12 have closer to 180° up to 5 kHz before it gradually narrows.
Vertially the K402 horn is around 55-60° down to 1100 Hz and becomes wider below that. I haven't seen a good enough measurement of the Jubilee vertically but considering the low crossover, the vertical directivity of the K402 should be similar to the Jubilee down to perhaps 400-500 Hz. The Coherence 12 has a wider vertical directivty in parts of the frequency, but also narrows as you go up in frequency. Especially above 1500 Hz the vertical direcitivity of the Coherence 12 narrows substantially, not totally unlike what you see in the polar grpah below.

So the Coherence 12 will minimize a lot of the vertical reflections from the room, especially above 1500 Hz.

A better comparison to the Jubilee is our horn speaker, the Vera Audio Sagarmatha. This has similar narrow directivity to the Jubilee a but unlike the Jubilee it's able to maintain the narrow vertically directivity much low in in frequency. And it avoids the typical floor bounce.

The top horn of the Sagarmatha was compared to the K402 in AB tests with level matching. The Klipsch 402 is to the right in the picture below.

 

[Bjorn]

For those who going or considering going to the exhibion in Horten in Norway the 20-21th of September, you'll have a chance to listen to the Vera Audio Coherence 12 speakers. Welcome.

Hi-Fi Messen

Hifi, HIFI, Messe, Horten

hifimessen.no

We'll be using external electronics with miniDSP Flex and Vera Audio power amps. Bringing also with us quite a bit of acoustic treatment that works above the 100-200 Hz area, plus some diffusion that operates between 500 Hz and 20 000 Hz.

 

[Bjorn]

Feedback from someone who recently listened to the Coherence 12:

"I'm not going to the show in Horten, but those of you who are going there should definitely prioritize hearing these speakers! On Friday I stopped by @lydogakustikk (sound & acoustics) to pick up some acoustic products and then got an exclusive listening session of Coherence 12 all to myself.

I can understand why these speakers are named Coherence. Because it's precisely the coherence and presence in the music that first strikes me when I'm trying to translate listening impressions into words. It's not that easy with this so-called flowery language, but I'll give it an honest try. So you'll have to bear with me

A fantastically delicious open sound! For me, it was quite unusual with such a wide baffle, and because very little sound then disappears to the sides, it gives a closeness and presence that you just have to love. Especially on vocals it sounds absolutely fantastic! And there's a kind of wonderful "lightness" about it all where everything just flows completely effortlessly and - yes, precisely - coherently. Although I've unfortunately never heard really good electrostatics, that's how I imagine them to sound.

Open sound can sometimes be a bit "in your face" in an unpleasant way. Coherence 12 is not there. They're not even close. Rarely, and perhaps never before, have I heard such a pleasant sound. "Oh well, on soft jazz then", you might think. No, I tested with symphonic metal. When a strong mezzo-soprano mixes with fierce guitar riffs and thundering drums, a choir sings at the top of its lungs in the background and a growling vocal comes in, it's best to make sure it doesn't fall apart and just end up in an unpleasant chaotic mess of sharp sounds that cut into your ears. Especially when the recording isn't very good either. Coherence 12 is not there. They're not even close

Look forward to Coherence 12 at the show in Horten! And thank you very much for the listening session, @lydogakustikk "

 

[Bjorn]

A few pictures from the Hifi Show in Horten in Norway we just attended.

Moving the speakers and measuring:

Side wall treatment with Broadsorbor Plus and BAD Arc.

The older and former RPG Diffractal diffuser in the rear of the room

I'll get back to share measurements from this room. Despite of the small 25m2 space, we received a lot of great feedback.

 

[Bjorn]

In this room, the speakers achieved the overall most even response when placed close to the front wall.
This was the response in the first seat in the middle. No room correction was used.

As we can see, this is very similar to how they measure above 110 Hz in my present listening L shaped room:

At the second row, it didn't measure that well but not terrible either. Here shown with different levels on Left and Right.

And on third middle row, we had this response:

Here's another picture from the Hifi show.

Driven by two Vera Audio amps and miniDSP Flex used as DSP.

 

[Bjorn]

The response on the first row is very close to a Bruel&Kjaer response, which is considered by many to be a neutral response. The Harman preferred curve is more bass heavy.

Here's the response on the first row for the left channel with lower resolution, which might be easier to compare to the Bruel&Kjaer.

 

[Bjorn]

Some of the feedback we received at the show was:
- Great midrange
- Very comfortable sound without harshness
- Clear and open sound combined with engaging sound and great bass
- Several commented how much deep bass the speakers had
- We were the first to achieve good sound at that particular room at the show (show has been existing for 23 years)

We also received many comments that we sold at very sober prices. When many saw the speakers in real life, they expected them to cost a lot more.

We played a lot of poor recordings. In retrorespect I wonder we played too many. If we play three poor recordings in a row and that's all someone are listening to, it might not give the best impression. Most likely I will update future play lists to to play every other good recording and something of less quality.

Another challenge is choosing the volume. We played probably around 80 dB at the first row the first day. Many other exhibitors played about 10 dB louder in general, which gives a sense of better dynamics and more powerful bass. But that also leads to listening fatigue over time, especially with many poor recordings as we had. In the future I may vary the volume more and turn up at least for a shorter period of time.

We obviously also have a job to do explaning people about external electronics and active design. Many automatically interpret active as having internal amps.

 

[Bjorn]

Here's a measurement I conducted of a speaker at a customer's home recently. The speaker costs five time as much as the VA Coherence 12 and that's without any electronics.

Notice the cancellation between 115 Hz and 200 Hz. This is very typical with almost all speakers and also floor standing ones. And this is a floor standing speaker by the way with three woofers above each other in bass reflex. It's also very common to see that even very expensive speakers don't have that much deep bass. I see this on a regular base when measuring setups. Much of the reason lies in too small cabinets or/and too small ports.

The Vera Audio Coherence 12 doesn't not suffer from the floor bounce and delivers very high level below 30 Hz. It can also be placed close to the front wall with a great result.

 

[DanielT]

A few pictures from the Hifi Show in Horten in Norway we just attended.

Thanks for the pictures, the description of the fair, your speakers and the measurements. Your speakers look really good. Stylish and measure really well. Good luck with marketing and sales.

I'll get back to share measurements from this room. Despite of the small 25m2 space, we received a lot of great feedback.

Size like a normal sized living room, not in an apartment then smaller, in Europe in other words:

We played a lot of poor recordings. In retrorespect I wonder we played too many. If we play three poor recordings in a row and that's all someone are listening to, it might not give the best impression. Most likely I will update future play lists to to play every other good recording and something of less quality.

Why? Play that kind of hi-fi trade show music that visitors like and that sells speakers. You're there to market and sell your speakers. Give them the best conditions to be sold.

Spoiler: Some song suggestions

Some tips. Songs, pieces, different styles of music that I also like, that I think would work well at a hifi fair:

Close to the mic, sung intimately:

Because it's so damn dynamic. Plus a good song too:

Damn good arrangement by Quincy Jones. Tight orchestra too:

Awesome with a big orchestra. A pretty wild piece. I like it:

Older hard rock can be quite bass poor. This one isn't like that. Best cover from Ozzy's farewell concert:

 

[Bjorn]

Thanks for the pictures, the description of the fair, your speakers and the measurements. Your speakers look really good. Stylish and measure really well. Good luck with marketing and sales.

Size like a normal sized living room, not in an apartment then smaller, in Europe in other words:
View attachment 478829

Why? Play that kind of hi-fi trade show music that visitors like and that sells speakers. You're there to market and sell your speakers. Give them the best conditions to be sold.

Spoiler: Some song suggestions

Some tips. Songs, pieces, different styles of music that I also like, that I think would work well at a hifi fair:

Close to the mic, sung intimately:

Because it's so damn dynamic. Plus a good song too:

Damn good arrangement by Quincy Jones. Tight orchestra too:

Awesome with a big orchestra. A pretty wild piece. I like it:

Older hard rock can be quite bass poor. This one isn't like that. Best cover from Ozzy's farewell concert:

Thank you Daniel!

Well, firstly I think a quality speaker should be able to play all kinds of music. I assume just like me, many vistitors do also play a lot poor recordings. So IMO it's good for people to hear how it plays with such music. But I would probably avoid in the future playing too many poor recordrings after each other and switch more.

Some of those exhibiting only used stellar recordings by the way.

 

[Duke]

We played a lot of poor recordings. In retrorespect I wonder we played too many. If we play three poor recordings in a row and that's all someone are listening to, it might not give the best impression. Most likely I will update future play lists to to play every other good recording and something of less quality.

Just my opinion: Play the best recordings you can unless you have someone in the room who shows sufficient interest that you want to show off how well the speakers do with poor recordings. People may not know much about the recording quality, or they may not remember to take it into account. I think people are more likely to be impressed by excellent sound with an excellent recording than by good sound with a poor recording.

 

[DanielT]

Thank you Daniel!

Well, firstly I think a quality speaker should be able to play all kinds of music. I assume just like me, many vistitors do also play a lot poor recordings. So IMO it's good for people to hear how it plays with such music. But I would probably avoid in the future playing too many poor recordrings after each other and switch more.

Some of those exhibiting only used stellar recordings by the way.

I completely agree. But...but at a fair well, hmm. Bravely done, I can say. Duke in the post above this one expressed it well, I think.

Plus they should be able to handle dynamic songs. That Michael Ruff song I recommended, this is what someone on another forum wrote about it. Requires a lot of amp power:
I will use the track Michael Ruff - Speaking in Melodies - Wishing Well (well-recorded fusion) as an example, as there are several high-frequency peaks that require a lot of power from the amplifier. First, the voltage, current and power for the entire signal are shown:


That Michael Ruff album was recorded at this studio:

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