Vanatoo Transparent One Encore powered loudspeaker system Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Vanatoo Transparent One Encore's frequency response in the farfield, and an Earthworks QTC-40 microphone for the nearfield responses. Except where noted below, all the testing was done using the speaker's 3.5mm analog input.

As the Transparent One has digital inputs, I used Apple's USB Prober utility to examine the USB input. This identified the speaker as "Vanatoo T1E" from "Vanatoo," with the serial number string "CTUA170405." The USB port operated in the isochronous adaptive mode, which allows the source to control the clocking of the data. This is generally felt to be less optimal than the isochronous asynchronous mode, where the DAC acts as the master clock. Apple's AudioMIDI utility revealed that, via USB, the Vanatoo accepted 16- and 24-bit sampled at all rates up to 96kHz; its TosLink and coaxial S/PDIF inputs accepted PCM data sampled up to 96kHz.

The analog input impedance appeared to be close to 10k ohms. Like other active loudspeakers using digital-domain crossovers, there was a delay when the Vanatoo was fed an analog signal, of around 5.4ms. There is no convention for specifying the sensitivity of a powered speaker, but when I set the speaker's volume control to its maximum and fed the speaker's analog input pink noise at 300mV, the resultant SPL was 90.7dB(B) at 50" on the tweeter axis. Pink noise at –20dBFS fed to the optical digital input gave an SPL of 89.1dB(B) at the same distance. The Vanatoo has sufficient gain to meet all needs. The enclosure seemed relatively inert with the knuckle-rap test, though when I investigated its vibrational behavior with a plastic-tape accelerometer I found relatively strong resonant modes at 242Hz and 375Hz on the sidewalls and top panel (fig.1).

619VT1Efig1

Fig.1 Vanatoo Transparent One Encore, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of top panel (MLS driving voltage to speaker, 300mV; measurement bandwidth, 2kHz).

The output of the Vanatoo's woofer, measured in the nearfield, is shown as the blue trace in fig.2. The minimum-motion notch in its output lies at 39Hz, indicating that this is the tuning frequency of the passive radiator on the rear panel. The passive radiator's output (red trace) peaks between 30 and 90Hz, and both this and the woofer's low-frequency output roll off much more quickly than the 12dB/octave slope that is usual in a reflex design. The complex sum of the nearfield woofer and radiator responses (fig.2, black trace below 300Hz) therefore rolls off with a sixth-order, 36dB/octave slope below the tuning frequency, presumably to protect the small woofer against overload.

619VT1Efig2

Fig.2 Vanatoo Transparent One Encore, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with the nearfield woofer (blue) and port (red) responses and their complex sum (black), respectively plotted below 300Hz, 400Hz, and 300Hz.

The black trace above 300Hz in fig.2 shows the Transparent One Encore's farfield response, averaged across a 30° horizontal window centered on the tweeter axis. It is superbly flat and even up to 10kHz, with the top audio octave slightly shelved down. The speaker's output drops like a stone above 22kHz, suggesting that the Vanatoo digitizes its analog input with a 48kHz sample rate. When I repeated this test with data sampled at 96kHz fed to the optical S/PDIF input, the response still died above 22kHz; the Vanatoo's DSP appears to be limited to a sample rate of 48kHz. The Treble control offers a boost or cut of up to 10dB at 20kHz; the Bass control offers a boost or cut of up to 8dB at 70Hz. Both controls had a corner frequency of 800Hz.

The plot of the Vanatoo's horizontal dispersion (fig.3) indicates a well-controlled radiation pattern, with evenly spaced contour lines that indicate stable stereo imaging. However, a slight gully develops off-axis at the top of the woofer's passband, which might make the Vanatoo sound a touch bright in small rooms or rooms that are not well-damped. In the vertical plane (fig.4), a suckout in the crossover region appears well above or below the tweeter axis, but the Transparent One Encore's balance will otherwise not change appreciably over quite a wide vertical window.

619VT1Efig3

Fig.3 Vanatoo Transparent One Encore, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

619VT1Efig4

Fig.4 Vanatoo Transparent One Encore, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45–5° off axis, reference response, differences in response 5–45° off axis.

In the time domain, the Vanatoo's step response (fig.5) reveals that the tweeter is connected in inverted acoustic polarity, the woofer in positive polarity. The decay of the tweeter's step smoothly blends into the start of the woofer's step, implying optimal crossover design, but the speaker's DSP is not used to render their outputs time-coincident. You can just see in this graph the acausal ringing of the A/D converter's anti-aliasing filter before the start of the tweeter's negative-going step. The Vanatoo's cumulative spectral-decay plot (fig.6) was superbly clean.

619VT1Efig5

Fig.5 Vanatoo Transparent One Encore, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

619VT1Efig6

Fig.6 Vanatoo Transparent One Encore, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Vanatoo's Transparent One Encore offers excellent measured performance.—John Atkinson

COMPANY INFO
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1600B SW Dash Pt. Rd #51
Federal Way, WA 98023
(855) 771-1161
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COMMENTS
Ortofan's picture

... the Transparent One Encore's DSP to make the output of its drivers time-coincident, as apparently KEF does in their LSX?
https://www.stereophile.com/content/kef-lsx-wireless-loudspeaker-system-measurements

Bogolu Haranath's picture

The Dynaudio Focus 200-XD, JVS compared with, are also DSP controlled time-coincident .......... See Stereophile measurements :-) ...........

Mike Rubin's picture

[Responded to the wrong comment by accident.]

Bogolu Haranath's picture

One more ....... Kii Audio Three loudspeakers (reviewed by Stereophile), are also DSP controlled time-coincident :-) ............

Mike Rubin's picture

I have lots of 24/192, 24/384, and DSD files that can only play through the Vanatoo DAC with downsampling or conversion to PCM, as the case may be. I want to buy a set of powered speakers in this price range for a basement system, but I am finding that it makes the most sense to use an external DAC into analog inputs in order to allow my higher-res files to play natively. That means I am concerned about the quality of powered speaker analog inputs.

Did you try these speakers through the analog input? Also, this particular product only has a 3.5 mm input, which will necessitate an RCA-to-3.5 cable, which will limit cable choice. Are cables with 3.5 mm connectors inherently compromised?

Other readers: which powered bookshelf speakers in the $500-1000 range have you found to have transparency and decent imaging through analog inputs, preferably RCA's?

Ortofan's picture

... Dynaudio Xeo 2 is presently available for $900/pr., down from $1500.
https://www.dynaudio.com/discontinued-models/xeo/xeo-2

https://www.stereophile.com/content/dynaudios-new-xeo-2

https://www.theabsolutesound.com/articles/dynaudio-xeo-2-wireless-loudspeaker/

https://www.avhub.com.au/product-reviews/sound-image/dynaudio-xeo-2-wireless-speakers-review-415505

https://darko.audio/2016/04/punch-a-higher-floor-with-the-dynaudio-xeo-2/

https://www.whathifi.com/dynaudio/xeo-2/review

Mike Rubin's picture

Will look into these.

Kal Rubinson's picture

I have lots of 24/192, 24/384, and DSD files that can only play through the Vanatoo DAC with downsampling or conversion to PCM, as the case may be. I want to buy a set of powered speakers in this price range for a basement system, but I am finding that it makes the most sense to use an external DAC into analog inputs in order to allow my higher-res files to play natively. That means I am concerned about the quality of powered speaker analog inputs.

If you are obsessing about higher resolution and DSD, you are going about it in the wrong way. The analog input on the Vanatoo is re-digitized at 24/48 PCM in order to utilize the DSP crossover and other internal digital functions. Surely, doing that that is a much more disruptive procedure than simple "downsampling or conversion to PCM."

Mike Rubin's picture

I agree that the digitization of the analog inputs sounds more destructive than whatever the DAC inputs do to higher-res files. Is this a universal issue with these particular powered speakers or one that affects all powered speakers? Do you know of any in this price range that keeps the analog signal from the external DAC in the analog domain?

Kal Rubinson's picture

I agree that the digitization of the analog inputs sounds more destructive than whatever the DAC inputs do to higher-res files. Is this a universal issue with these particular powered speakers or one that affects all powered speakers?

Neither. Non-DSP active/powered speakers are basically speakers with their analog amps and analog crossovers internalized and, therefore, keep everything in the analog domain. DSP active/powered speakers depend on digital processing to do crossover and other useful machinations (as with the Vanatoo) but they do that in the digital domain. Thus, it is generally better to feed them with a digital source than an analog source.

Do you know of any in this price range that keeps the analog signal from the external DAC in the analog domain?

There are many small, inexpensive active speakers without DSP but I have no personal experience in that realm.

Mike Rubin's picture

Makes perfect sense. I should have thought this through before asking.

Bogolu Haranath's picture

You could look into the Tannoy Reveal 802 active speakers ....... The signal stays in the analog domain ...... No DSP ........ Now available at Amazon for $200/pair :-) .........

Mike Rubin's picture

Thanks for the suggestion. Will look into these.

Bogolu Haranath's picture

Tannoy Reveal 502 and 402 active speakers are also available at Amazon for even lower price ......... No DSP ........ All analog ....... There are several reviews and answered questions available at Amazon :-) ......

mrkaic's picture

It is strange to think that reviewing a lower price item = demotion. :)

But more importantly, JA could open the boxes and measure the amp section in isolation. Just as any other amplifier. Would be quite informative to those of us who read mostly JA’s measurements and skip the rest.

Kal Rubinson's picture

How would that be informative? The speaker cannot be used without the amps nor can the amps be used without the speaker.

mrkaic's picture

When you have a system, you want to know how its parts behave. The fact that the amp and the speaker are in the same box does not change anything.

Also, I don’t agree that you could not use the amp without the speaker. Take.it out of the box and use it. If nothing else, it would be fun.

Bogolu Haranath's picture

How low can you go? :-) ........

"Limbo Rock" ......... Chubby Checker :-) .......

Kal Rubinson's picture

When you have a system, you want to know how its parts behave. The fact that the amp and the speaker are in the same box does not change anything.

I can understand your curiosity.

Also, I don’t agree that you could not use the amp without the speaker. Take.it out of the box and use it. If nothing else, it would be fun.

OK. Then you can measure the two amps when you do but the task is hard to justify except for idle curiosity.

mrkaic's picture

...but I am a curious guy. And I’m not the only one around here.

Kal Rubinson's picture

Perhaps. I doubt that many are curious about this particular matter.

Bogolu Haranath's picture

In almost all of the active speakers, each individual amplifier is connected to each individual driver in the speaker ....... So, they both are optimized for each other ....... and, both are optimized to the active crossover which is placed before the amplifiers ........ So, all these individual components are optimized to work with each other ....... Each individual amplifier, driver combo is optimized for certain limited frequency ........ Let us say a 50W amp is connected to a tweeter, and a 100W amp is connected a woofer ......... In a DSP speaker a DAC is also included in the package :-) .........

In a passive system, speaker designers try to make their speakers work with as many different amplifiers as possible ........ Same way, amplifier designers try to make their amplifiers work with as many different passive speakers as possible :-) ..........

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