GRIMM Audio LS1c & SB1 DSP Speaker Review

[olieb]

I am always puzzled with the Early Reflections graphs. The ceiling bounce dips at 1.5 kHz. As I read it, this means that less energy is reflected at 1.5 kHz relative to other frequencies. Why then would ceiling absorbers help solving this?

The problem is not missing energy, but energy that is unevenly distributed over the frequency band.
If you absorb the reflection, it will have lower level and lower energy in all frequencies. And so the impact of this reflection on sound/FR will be reduced.

 

[Robbo99999]

Not sure I understand the appeal of the bass rolling off gradually from 100Hz (albeit it almost in linear fashion rather than in an "accelerated" way) when you're talking about a system that includes a sub for a good many thousands of dollars. Maybe the idea is the gradual roll off fits well with room gain so that they're designed to be plonked in a room without thought and still sound about right bass wise. Doesn't sit with me quite right, the horizontal dispersion is amazing though.

 

[prestigetone]

Not surprising. These are phenomenal speakers with practical design in mind. This speaker is the OG active home entrant that gave way to pretty much a lot of what is currently on the market and trends resulting in smaller digital amps and purifi woofers. Go look at the spin results and a lot of Brunos work is at the top.

The first time I heard of these, a mastering pro told me these would be their endgame. First time I heard them I was blown away.

 

[trevor_bartram]

At this price why not use dual opposed sub drivers to reduce even order distortion and increase output, in a bigger box that will fill in that ridiculous hole & improve WAF?

 

[SigbergAudio]

It looks like a slope that may match room gain pretty well. In addition to that you can adjust the gain level of the sub, so I suspect one can get as much bass one would want, within the limits of the system of course.

 

[stvnharr]

It’s great to have an expensive speaker reviewed, thanks @amirm. This one seems to justify its price point to some extent. At least it performs exceptionally which is the minimum for something as costly.

I think the waterfall is worth further discussion. I haven’t seen anything as clean reviewed on ASR which suggests that it offers superior time domain performance, something not shown in other measurements. I know Amir doesn’t hold much weight in CSD data, but I would like to understand which other data set(s) tell us what the waterfall does? It’s especially interesting to me because the subjective impressions are possibly the most positive I’ve read from Amir.

Also does the preference score take time domain performance into account? I don’t think so.

Matt,
The Waveform speakers that we have discussed previously had a waterfall plot much like the Grimm's, no resonances. And I always thought that that was a big reason why they sounded so good.
We have been there before.......
Steve

 

[Sokel]

It looks like a slope that may match room gain pretty well. In addition to that you can adjust the gain level of the sub, so I suspect one can get as much bass one would want, within the limits of the system of course.

Hence the not exact stated crossover point as it goes higher with level if fixed.

 

[Avp1]

The burning question for me is whether Grimm also sent Amir an MU2 DAC to test!
Some bold claims by Grimm about their proprietary FPGA design. From the manufacturer’s website:

At the heart of the MU2, Grimm Audio’s proprietary Major DAC can be found. It is of a groundbreaking discrete design that makes optimal use of our own FPGA board. In a unique way our high resolution Pure Nyquist upsampling filters are combined with a fundamentally flawless 11th order noise shaper of 1.5 bit.

Darko recently proclaimed it the best DAC he’s ever heard….

When you use Grimm speakers, you better feed them digital audio signal. DACs are already there, one for each driver.

As to bass performance. it is really disappointing for the price, but is not a surprise considering the size of woofer and its housing. This is of cause if there was no setup errors made by Amir.

 

[AudioKC]

No, the room does not modify the bass response of any speaker.

My man What a statement.

Tell it to my Neumanns that are fighting comb filter every day in 100-200hz

Talking about speaker.

a) overpriced (given that Dutch&Dutch or Gelnelec 8361A on the market)
b) to be fair, quite messy mid range with all these ups and downs, like a saw blade
c) not sure, I might miss it, there is no room correction out of box, for that price... well.

I bet Dirac Live with Bass Control + Good speakers + Good subs will work even better than this 30K+ product. And you will be able to invest 20K into your kids college fund... Just saying.

 

[Avp1]

According to the Audioxpress article,https://audioxpress.com/article/grimm-audio-building-the-dream GRIMM has a particular philosophy of digital audio processing .

"Grimm’s team found that getting the amplitude errors low enough required much more processing power than was available in typical converters, which led to the use of a powerful FPGA calculation engine in the MU1. It offloads the first (and most demanding) upsampling stage from the DAC chip to the FPGA. It was decided to output the signal in AES or S/PDIF form to the DAC so the MU1 clock quality could be transferred to the DAC (remember that clock and amplitude errors have similar impact). That is the reason why the MU1 does not offer USB audio — the clock in the DAC would be another unknown. By offering the signal in AES or S/PDIF format with its embedded clock, Grimm makes certain that the DAC is benefiting both from the MU1 processing and its high-quality clock"

They apparently are not aware of ASRC and asynchronous audio mode in USB where clock is supplied by receiver side.

 

[Matt_Holland]

Darko seems to be one of the very rare people that can hear differences between DAC's that measure completely transparant. He must be from "Darko Dumbo ears Planet" or something..
P.S. I do find his videos entertaining

I find Darko insufferably boring and smug, although I acknowledge he’s a good presenter and his production standards are very high.

There are a lot of people who hear differences between DACs. Expensive and esoteric DACs are for these people.

 

[Davey]

My man What a statement.

If you don't understand the statement, that's not my issue.

 

[Matt_Holland]

I tried their Mu1 when it was released do you want to have a guess at the amount of difference it made?
Keith

As a retailer for high quality audio, some of which is quite expensive, how do you deal with a client who “hears” DAC differences and wants to spend good money on one? Do you re-educate them or humour them?

 

[Purité Audio]

I just say that they can of course buy an expensive dac but it won’t improve the quality of sound, and the money would almost certainly be put to better use either buying better speakers and/or looking at the speaker room interaction.
Keith

 

[AudioKC]

If you don't understand the statement, that's not my issue.

but you would agree, statement is quite funny, given modern understanding of acoustics.

 

[Geert]

Hence the not exact stated crossover point as it goes higher with level if fixed.

”3-way woofer settings - Here you can control some parameters of a connected subwoofer. First you can set the gain. If you use the Grimm LS1s subs, the system is linear in the free field (onaxis) with a 0 dB setting. Dependent on your acoustics you may like to use a slightly lower or higher value. Since the crossover frequency is 70 Hz, the gain control acts like a low-shelf EQ below this frequency”.

The 70 Hz crossover point is confirmed by Amirs measurements. The crossover point moving with the subwoofer level is a bit dubious, because the filters cutoff frequencies don’t really change.

 

[olieb]

The waterfall plot might be not so outrageously good, if one could compare it to other speakers.
The height from floor to signal is quite small, only about 10dB. For other speakers much more low level stuff was shown.
Here for comparison the plot for Grimm LS1 (left 10dB) and Neumann KH150 (right 20dB).

With the same elevated floor the Neumann would look even cleaner than the LS1.
It is a bit of a pity we cannot see what lies beneath for the LS1 (perhaps it would still come up empty?).
Maybe @amirm, you can replot with the available data?

 

[amirm]

As to bass performance. it is really disappointing for the price, but is not a surprise considering the size of woofer and its housing. This is of cause if there was no setup errors made by Amir.

To be clear on this point, I spent half a day playing with different bass optimizations in NFS. All other variations I tried, reduced the level of bass so the default was optimal.

FYI company got back to me stating the same point @Davey made earlier in the thread that sub should not be measured anechoically. So no "mistake" but different views on how such speakers should be measured.

 

[PristineSound]

The waterfall plot might be not so outrageously good, if one could compare it to other speakers.
The height from floor to signal is quite small, only about 10dB. For other speakers much more low level stuff was shown.
Here for comparison the plot for Grimm LS1 (left 10dB) and Neumann KH150 (right 20dB).
View attachment 452327
With the same elevated floor the Neumann would look even cleaner than the LS1.
It is a bit of a pity we cannot see what lies beneath for the LS1 (perhaps it would still come up empty?).
Maybe @amirm, you can replot with the available data?

Excellent and legitimate point.

Hard to imagine any speakers with absolutely no resonance, even with the stiffest cabinet.

 

[amirm]

Maybe @amirm, you can replot with the available data?

It is always hard to figure out what range to use. But sure, he is 3 dB lower noise floor which now shows a couple of resonances: