Ascilab A6B Speaker Review

[Lars Risbo]

ported rolls off 24dB/Octave. PR is more complex being a 5th order function with a deep notch (complex zero) at the PR free field resonance. This null makes the bass roll off quite steep depending on where the free field PR resonance is (this is why a large area PR helps like in S6B using 8” PRs which needs more mass loading and hence lower resonance).

It’s not really possible to make a working port for these compact boxes with such huge output and going so deep. PR is the solution here.

 

[emmodad]

Here ya go, Amir
Size large
Lowpass(out) filter included...

 

[EERecordist]

This is a review, listening tests and detailed measurements of the Ascilab A6B Stand-mount speaker with Purifi woofer and passive radiators. I purchased this I have been on a mission to better correlate distortion measurements to audibility. Here, I could hear the start of very low frequency distortion at 96 dBSPL and heard the speaker nearly completely run out of excursion at 101 dBSPL. How can we better figure out from the graphs. Check this work in progress:
View attachment 515083
These are THD% levels charted below 200 Hz. That is where I heard the distortion. Above that, we are overdriving the speaker anyway relative to music.

We see a more or less plateau above 100 Hz indicating we have made the right choice regarding cut off at 200 Hz.

Below that we see different slopes in distortion. We see two distinct new distortion sources coming into play which I have marked as secondary and tertiary. I have placed a circle at the knee of those events. What this says is that you can play down to 42 Hz at 96 dBSPL whereas if you crank up to 101 dBSPL, you best stop at 65 Hz! This matches my hearing of the sweeps where I heard slight distortion at the very start of the 96 dBSPL sweeps. Whereas with 101 dBSPL, that lasted quite a lot longer and at much higher levels of audible distortion.

Going the other way, if you are playing at 81 dBSPL, you can essentially take advantage of the full response down to 30 Hz. We will see if this and the above prediction proves to be the case in listening test section.

Assuming above is correct, you don't need a subwoofer for 81 dBSPL and possibly 86 dBSPL. Above that, a subwoofer would be needed for those playback level and the frequency for that crossover is on the chart.

Good work, good speaker.

To this graph, I wonder if a university, the driver designer, or a very large audio equipment maker has used real time LIDAR to study where the harmonics are generated physically? Klippel may be doing something.

I think documenting the transition points, your circles, is a clue. I think there have been studies of the nonlinear modes of speaker cones/diaphragms. A cone is supposed to act as a perfect piston, and the more rigid the material the more it would be.

In the future, when the supply increases, it would be interesting to get these in front of some experienced tracking, mixing, and mastering engineers.

 

[Chaos01]

It is interesting to see the 86 dB/1 m distortion which is perfect and then the 96 dB/1 m which is far from. I am currently running a pair of R3 Meta and have not gotten around to integrating the subs. They don't go nearly as deep, and I'm sure their woofer is not optimized for high excursion, but they seem perfectly adequate in my roughly 60 m² (and 2.6 m high) living room. But then, what I consider loud listening is about 70 - 75 dB at the listening position, and I measured peaks of 83 dB at 1 m from each speaker with a calibrated sound level meter. This is reverberent field, so if I took them outside with the same setting, they'd probably measure lower.

So if other people are like me, these AsciLabs might be perfectly adequate without subs even in larger rooms, at least as you don't try to correct for suck-outs. Now for those who prefer to use subs, a closed box version would be highly desirable.

Yes, If you dont want a sub. But remember the price, at Audiophonics the cost 3790€ (imho to much over the msrp but i digress) i paid 3400€ for new R3 Meta with the KF92. And think about room modes, whats better for you. Other Hand No Time consuming Sub integration needed. The R3 Meta Distortion values are pretty good too for the Money, and the vertical Dispersion is a bit better. Of course the A6B is a beast and worth it but not a easy decision.

 

[dfuller]

The Purifi woofers are almost impossible to design with ports. The port probably needs to be 16 inches long.

Well, the good thing is ports don't have to be straight. They can be bent to fit in a cabinet.

PRs create 12dB/octave rolloff. Ports 18dB/octave rolloff.

Nope. PRs are 5th order (30dB/Oct) ports 4th order (24dB/Oct). Sealed is 12.

 

[peniku8]

I have been on a mission to better correlate distortion measurements to audibility. Here, I could hear the start of very low frequency distortion at 96 dBSPL and heard the speaker nearly completely run out of excursion at 101 dBSPL. How can we better figure out from the graphs. Check this work in progress:
View attachment 515083
These are THD% levels charted below 200 Hz. That is where I heard the distortion. Above that, we are overdriving the speaker anyway relative to music.

We see a more or less plateau above 100 Hz indicating we have made the right choice regarding cut off at 200 Hz.

No need to get creative and waste time on trying to come up with a new standard when CTA-2010 was created specifically for this purpose (classifying low frequency distortion in terms of audibility). It's probably also easily adapted to your hardware. CTA-2034 also has a standard for burst SPL measurements.

 

[WeekendWarrior]

C6B + 2 good subs = A6B? Or is there extra goodness in the A6B?

Asking as an owner of the former, wondering if the later is worth the investment.

 

[jhaider]

I just noticed that none of the pics on their website show grilles for woofer or PRs

Is this speaker another unfortunate case of audio engineering excellence hobbled by usability fail?

 

[Steakhouse]

Given the woofer used, the clean output capability likely exceeds anything else of the same size. So if you’re happy with the output capability of pretty much any other 7” woofer speaker then you’ll be under the limits of this one.

I don’t know what if any other high-performance 7” woofer speakers (if any) @amirm has on hand (KH 150? M126Be? R3 Meta or Ref 1M?) but it will be interesting to see how the numbers on this distortion test start to stack up.

Yeah, in the end it is a 7" woofer in a compact speaker. If it were a bass reflex speaker we would probably have port chuffing at such a low extension.
I think the reason why maybe you wont hear distortion with this sweeps on a Neumann KH150 (6.5" woofer) is because those active speakers mostly have limiters that prevent them to be pushed into distortion.

On thing I would like to mention is that those measurements and listening test here are done with one speaker which underestimates bass headroom in a stereo system. Having two speakers should give you 3-6 dB more headroom.

 

[Sernyl]

Sorry if that has been posted already.
Am I wrong ?
I had found somewhere on the web (including ASR) the ASCILAB's name topolgy :

S = as Signature, model using the Purifi transducer assembly
A = as Aluminum, aluminum woofer and ceramic-aluminum tweeter
C = as Ceramic, ceramic-aluminum woofer and ceramic-aluminum tweeter
F = as Fibre woofer, woofer with (aramid) fibre and aluminium tweeter

¤ the middle number represents the Ø of the main converter in inches

¤ the last letter indicates the type of enclosure
B = as Bookshelf, as shelf / stand - opposite where it belongs
C = as Cardioid, cardioid radiation - also quartic, simply directional characteristic

if it is right, A6B is for Aluminum, and the Purifi. would be S6B


Regards,

 

[rolfrander]

I had found somewhere on the web (including ASR) the ASCILAB's name topolgy :

S = as Signature, model using the Purifi transducer assembly
A = as Aluminum, aluminum woofer and ceramic-aluminum tweeter

S has both purifi woofer and tweeter. A only has purify woofer.

 

[IngMishael]

awesome

 

[Steven Holt]

Even with the 'theoretical distortion' at high SPL, these are excellent speakers, no doubt. World-class. The real question, I think, is why should we buy these speakers when we can get the LS50's at less than half the pair-price, pair it with an SVS sub and have a system on par, maybe better?

 

[MZKM]

Preference Rating
SCORE: 6.7
SCORE w/sub: 8.3

Sensitivity: 83.8dB (300Hz-3kHz ; spec: 82dB)
Frequency response: ±14.9dB 20Hz-20kHz ; ±4.2dB 80Hz-20kHz

​

 

[hex168]

PRs create 12dB/octave rolloff. Ports 18dB/octave rolloff.

Sealed is 12 dB per octave (varies a bit with Qts), not PR. Ported is 24 dB/oct, PR is similar but rolls off a little quicker due to an added null.

 

[DanielT]

Thanks for the test Amir. Those were superb speakers.

@amirm

Firstly many thanks for a very revealing and interesting review. Obviously we are looking at SOTA speakers. A couple of questions.

1. The Topping LA90 amp only produces 41 watts into 8 ohms. Do you feel that these speakers would benefit from more power, especially in relation to reproducing frequencies below say 60hz?

2. If you did want to drive them at very high levels, say in excess of 96db, would it make sense to add a high pass filter before the LA90 amp so that the speakers are only trying to reproduce above say 40hz (or 35hz) as there are very few songs that would be affected. It would also take load of the amp.

3. Taking into consideration 1 & 2 would the Wiim Amp Ultra be a better choice of amplifier as it has twice the power (100 watts into 8 ohms) and using the Wiiim App a built in high pass filter (simply set the sub out crossover to 35hz but without a sub attached). I note that the Wiim is less expensive, but only has a SINAD of 100db compared to around 118db for the Topping, however, would that be audible?

Thanks in advance .... pls keep the reviews coming, they are much anticipated and appreciated.

Even if we take the 56 watts into 4 Ohms for the Topping LA90 amp. Ascilab A6B, what did they have, 82dB sensitivity? That's equivalent to if I were to feed my 90dB sensitive speakers with 9 watts. I think that's too little anyway. At least if I play at higher volume with fairly dynamic music.

 

[Raiju]

There's a pretty large low frequency extension between Ascilab's measurements (April 2025) and ASR's measurements.

If I take the 100 Hz at the reference level, then -10 dB is at ~33 Hz with Amir's measurements, whereas -10 dB is at ~29 Hz with Ascilab measurements. Alternatively, at the same 30 Hz frequency, Ascilab's measurements are a few dB higher (-14 dB for ASR, -9 dB for Ascilab). Isn't the Klippel NFS system supposed to get rid of this level of uncertainty or are there some different settings (smoothing?) at play?

I compared the two in spinorama and the difference is quite visual.

 

[Matias]

I would pair these speaker with at least a Hypex NC502MP, or better yet, Hypex NCx500 or Purifi 1ET6525SA based amps. Plenty of clean power.

 

[Purité Audio]

I use Fred’s (Boxem) Arthur 4216/E2 with both A6B and S6B appears to absolutely everything I want or need..
Thank you as always for he measurements Amir excellent work as always.
Keith

 

[mps]

> NOTE: My company, testedaudio.com, is the exclusive distributor for Ascilab products in North America. While objective tests remain the same as for any other speaker, subjective remarks may have business bias.

Props for the upfront honesty (which makes me more likely to add weight to your subjective remarks).