Interesting new studio speaker design from present day production

[neRok]

All talk and no measurements to back up the 'extraordinary' claims.

There was this measurement when they were talking about how good the crossover filters were with respect to phase response;

...achieved results so good that he even fooled the highly respected live sound engineer next door to us who's been designing building and calibrating high-end speaker systems for decades, he kindly came in and measured the system using the Rational Acoustics smart suite and even then couldn't reliably tell where the crossover points were either in frequency or phase response, and that's some achievement

 

[fluid]

There was this measurement when they were talking about how good the crossover filters were with respect to phase response;

The problem with that image is that it is not a measurement of their speaker but a stock picture from a youtube video on using SMAART's delay finder function

That doesn't mean what they said isn't true (as many people use stock images in their videos).

 

[ctrl]

There was this measurement when they were talking about how good the crossover filters were with respect to phase response;

"...and even then couldn't reliably tell where the crossover points were either in frequency or phase response, and that's some achievement"

Well, that's one of those statements...

So the statement must refer to a measurement of the speaker with deactivated FIR filter. Because the first thing to do when using FIR is to eliminate the excess phase caused by the crossover filter.

Or they simply mean that they have set the FIR filters "properly", so that the phase rotation of the crossover filters are no longer recognizable on the phase frequency response with FIR filters (in one specific reference point) - which is not witchcraft nowadays (see last section below).

But with FIR filter deactivated this statement would not be a good thing per se, because when using standard crossover filters (LR2, LR4, BU3,...) the phase frequency response can provide information about filter order and possible crossover frequency - with exotic crossover filters this becomes more difficult and with bungled crossover it will be impossible.


For those who are interested, here are a few more details...

As an example a typical 3-way loudspeaker with Linkwitz-Riley fourth order crossover filter at 400Hz and 3000Hz. If measured correctly (dual channel measurement or similar), you will get something similar to this:

If we would not have the individual measurements of the drivers, only FR (black) and phase frequency response (grey), we could still make some assumptions.

The lowest low frequency range usually behaves like a minimum phase system, therefore the order of the high pass filter (e.g. for CB speaker it would be two) can be derived directly from the frequency response.

In our example, the FR to low frequencies drops by 18dB per octave. This corresponds to a third order filter, i.e. 270° phase rotation (90° phase rotation for each order).
So we mark this phase rotation on the phase frequency response.


In the mid and high frequencies we can see about 2x360° phase rotation, which indicates two fourth order crossover filter. With ideally designed "symmetrical" filters, the crossover frequency would be halfway through the phase rotation.

Note, however, that the filters affect each other, so this is not an exact method, but provides an approximation for the crossover frequencies.

Conversely, you can also start with the high frequencies, then the crossover frequencies correspond exactly to the graphical transitions from +180° to -180° of the phase frequency response in gray - which would give a better match in our case. Normally you would back this with near-field measurements of the drivers.

The German S&R magazine regularly carries out exactly such a analysis in its reviews of active and passive loudspeakers. As an example the KH310 review:

Phase response on axis measured at 2 m distance. At the crossover frequencies of 650 Hz and 2 kHz there is 360° phase rotation each and at the lower end of the transmission range there is another 270° due to the 1st order electrical high pass filter and the 2nd order acoustic high pass filter (closed cabinet).

Source: S&R magazine


With FIR filters removing the excess phase of the crossover filter, there is not much left to interpret (if you don't have the single driver responses).

Ideally, the phase behaves like a minimum phase system and can be derived directly from the amplitude frequency response.

Update: With FIR filters, of course, the remaining phase frequency response rotation can be linearized - but that would be another topic.

 

[sam_adams]

All talk and no measurements to back up the 'extraordinary' claims.

There was this measurement when they were talking about how good the crossover filters were with respect to phase response;

The problem with that image is that it is not a measurement of their speaker but a stock picture from a youtube video on using SMAART's delay finder function

This is why I have little faith in YouTube only type reviews. @amirm's approach to measure and post the measurements and then use video as an adjunct to the measurements to provide more context which aids in understanding is far superior. The YouTube 'reviews' seem to focus more on breathless hyperbole than on actual substance.

 

[Somafunk]

New video up, with a valid dig at the doubters.

 

[juliangst]

Watched all parts now.
Really interesting and entertaining project. If it works well for them in their room they really saved a lot of money

 

[fpitas]

Cute cat

 

[DJNX]

Ahaha.
ASR called out, and with good reason.
They promised three videos about these speakers and people in here were already dismissing them before watching the entire first video.

Hope we will be able to be better next time.

 

[Purité Audio]

I didn’t see any measurements for the speakers except the in -room Trinnov?
Keith

 

[DJNX]

Yes, only in-room response, so these speakers are still a question mark.
Will have to wait for anechoic or Klippel measurements.

 

[juliangst]

Ahaha.
ASR called out, and with good reason.
They promised three videos about these speakers and people in here were already dismissing them before watching the entire first video.

Hope we will be able to be better next time.

People hate so much on ASR for exactly this hostile behavoir and I don't blame them.
If ASR wants to get a better reputation people here shouldn't call out reviewers and youtubers behind closed doors like this

 

[Purité Audio]

ASR calls them out completely in the open, no sugar coating here.
Keith

 

[Scgorg]

In all fairness to them: this is clearly not intended to be a very technical series. They're covering some of the very basics (such as referring to TS-parameters in that latest video), but their focus is not "how to engineer a speaker" as much as it is presenting "we made a speaker, here's a little look at what we did". The point of the speakers being made specifically for their room also holds, I think. Consider the very extreme scenario of listening to a speaker in an anechoic chamber - the only thing that matters tonality-wise is the frequency response at the listener's axis. In other words you can at least partially compensate for a speaker's directivity deficiencies with room design (whether you should do so instead of making a more high-performing speaker in the first place is a different discussion). The negative of this is of course that the speaker won't necessarily be the best alternative for a wide variation of rooms, which is what professional manufacturers have to consider. This is also why offering something like this as a kit is giving me a bit of pause, and I would hope that a kit release also means they will release at least some rudimentary measurements so potential builders know what they're getting.

I think we should commend them for taking the step of trying to design their own speaker, it's easy to chastise someone else's choices in design without actually ever doing anything yourself. Just like the rest of you I'd love to see a full measurement suite on these speakers - and it would surely reveal flaws (as with almost any speaker) - but does it really matter? The absurd entitlement exhibited by some members in this thread is incredibly grating even to me as a bystander, I can't imagine how annoying it is to these people making this as a fun little video series. Let's not demand any more than what we can reasonably expect from a DIY speaker, which is what these are. These are not professional speaker engineers with access to anechoic chambers, advanced simulation software, and $$$$$ equipment. If that doesn't sit right with you then you're simply not the target audience, and that's okay.

 

[ernestcarl]

I believe it’s the catchy phrasing of “best speakers” which is what annoys others here. Sometimes we need to step back and realize their channel is primarily “infotainment” and is not a dedicated DIY speaker building channel. In the end it only matters that they achieved the goals they set out for their studio space. That said, if one is going to be selling a product, I much prefer to see more detailed measurements.

 

[Purité Audio]

They are intending to sell this design though , so provide some measurements otherwise just another kitchen sink manufacturer and there are already more than enough of those.
Keith

 

[Laserjock]

I’ll wait for the completed, independent measured and commercial build of a finalized product.

 

[Phorize]

Seems like they want to have their cake and eat it. On one hand it's just their own project for their own studio, but here's a new studio monitor we might release-we've actually branded it but we don't want to be speaker manufacturers. Lol.

 

[mumford]

They want to sell flat pack. Depending on the price, it may or may not be a good option. The following is retail, low quantity, pricing. If they can get dealer pricing, they can make some money while offering a good package.

tweeter T-25s $129
mid M-74-S6 $299
woofer Dayton RS-225-4 $85
plate amp Fusion FA-253 $539
CNC wood cutting, screws, and why not $xxx

So, we are looking at $1052 + $xxx + shipping. The crossover is probably 4th order at 400Hz and 3000Hz. Maybe add a couple notch filters. Should not be too difficult. The box is sealed. However, Hypex Fusion does not do FIR filters.

 

[Somafunk]

Watching their 3hr video now, was live streamed earlier and it goes into design, set up, engineering design etc. Lots of relevant information and well worth watching (if you’re interested that is)

 

[ernestcarl]

Watching their 3hr video now, was live streamed earlier and it goes into design, set up, engineering design etc. Lots of relevant information and well worth watching (if you’re interested that is)

I wonder if the deliberate 3.5 kHz upper mid dip is due to how used to they've become of their previous monitors -- i.e. habituation. Still lacking in measurements we've become accustomed to here in ASR... raw or unequalized per driver unit/section measurements might reveal other possible reasons for the apparent "need" of the dip.