GRIMM Audio LS1c & SB1 DSP Speaker Review

[Hayabusa]

Stereophile measurements are quite erroneous in bass, showing a hump that is not there. That aside, no, I did not mess with the software other than selecting 3-way and which sub was in use. I am testing a system. That system takes a day to measure and process. Stereophile is making in-room measurements that take seconds so they can afford to mess with settings.

Regardless, this is the feedback from the company, not stating anything about settings:

"how did you measure the sub? Since it is intended to be used on the floor it must not be measured in free field."

I explained to them that I measure all speakers free field so would not be fair to test theirs differently. Their suggested method is ground measurements like traditional subwoofers are measured. I get that but again, I treated the speaker as if it were one unit, not some separate subwoofer stand-alone. Maybe I should do this kind of testing in the future but for now, all measurements are done the same way (anechoically).

Keep in mind that company provides this measurement for the original LS1:

View attachment 452962

Notice what I have highlighted. That it is a simulation, which I assume it means assumption of room/floor loading. I checked this specifically since I was not getting the same measurement and then noticed the fine print.

Also, anything you can do in DSP of this speaker to boost bass, you can do the same with other speakers. So it is not fair to go and do that to this and not to others.

Finally, I listened to the speaker and noticed deep bass to be soft. It plays it a lot better than any bookshelf but is not in the same class as other full range speakers such as my own.

As stated multiple times, this is a high performance sub but in a tiny enclosure. It is not going to spit out 20 Hz at high SPLs. And it is tuned that way. It may sound more boomy as it excites more room modes if it had lower response. So it increases the chances of good sound for the user.

I will repeat my question: what was the high pass setting of the sub set to?

Also ground plane v.s. free field can explain max 6db difference, your graph shows much more than that, thats why many in this thread have doubts about the results.

Do you still have the speakers?

 

[Hayabusa]

As stated multiple times, this is a high performance sub but in a tiny enclosure. It is not going to spit out 20 Hz at high SPLs. And it is tuned that way. It may sound more boomy as it excites more room modes if it had lower response. So it increases the chances of good sound for the user.

Then there is the distortion figures: 10%@30Hz 86db: With a 10 inch speaker that is feedback controlled that supposed to reduce distortion by 20-30db!
I just don't buy it, something is wrong.. Can you please double/triple check if you still have the speakers?

 

[kyuu]

If there was a serious problem with the measurements, where a setting was obviosuly wrong, why didn't the manufacturer say so in their response to Amir?

 

[Hayabusa]

If there was a serious problem with the measurements, where a setting was obviosuly wrong, why didn't the manufacturer say so in their response to Amir?

Good question, I have no idea, I would not settle for these distortion figures if I had all kind of publications showing how good my digital feedback system reduces distortion.
Grimm: are you reading this? can you explain?

 

[amirm]

I will repeat my question: what was the high pass setting of the sub set to?

As I said, I am using the defaults for 3-way setup:

20 Hz is as low it goes.

 

[amirm]

Also ground plane v.s. free field can explain max 6db difference, your graph shows much more than that, thats why many in this thread have doubts about the results.

No one has any real knowledge of how this speaker is designed. Speculating that it should have more bass does not make it so. Don't you think the company would be the first to quiz me on your trivial questions if they thought those were the issues? I suggest moving on.

 

[amirm]

Cannot speak for the manufacturer but I understood their statement so that a system with a groundplane subwoofer does not need a flat mode, as everyone will place it on the floor, no-one will listen to it under anechoic or free-field conditions.

Once again, all other speakers with extended bass will be on the floor as well. We don't give them that boost, why start here?

 

[Hayabusa]

No one has any real knowledge of how this speaker is designed. Speculating that it should have more bass does not make it so. Don't you think the company would be the first to quiz me on your trivial questions if they thought those were the issues? I suggest moving on.

not nice to call it trivial questions Amir, I am just trying to solve the mystery here..

 

[Mart68]

Yet... These speakers appear to sound very, very good by all (most) accounts.

It's almost like the designers of this speaker knew what they were doing, possibly even more than people on audio forums.

I had a demo of them when I was in the market for new speakers - I thought they were quite unspectacular and not worth the money (they were a lot less than forty grand at the time).

Not all people on forums don't know what they are talking about. Especially here. The speaker is compromised to an extent not justified by its price. That is nothing new of course, many speakers fall into that category. They are good speakers, but you can get better for a lot less.

 

[Vuki]

Maybe even without sub? Do you have the full print?

Audio.de test

 

[SorenTyson]

There seriously taking the piss with its 40k price

At least they are serious enough to send them to Amir. I am sure we would be shocked if we saw the measurements of some of the other exotic speakers out there

 

[Hayabusa]

Audio.de test

Indeed it looks like they only measured the LS1 without sub here..... My question marks only became larger now..

 

[Liberal Democracy]

Thanks for this Amirm , always wondered about these . They looked like a interesting design to me , I do get bored of the standard box with a few drivers in designs .

They were really quite reasonable money a few years ago , I wonder how many pairs they sell a year now . Maybe they could be sold as a self assembly kit , now the designer has moved onto other projects . That would be a good gift to the community and maybe some good PR.

 

[Geert]

not nice to call it trivial questions Amir, I am just trying to solve the mystery here..

I’ve also been wondering what's going on since this review was published but kept quiet because we need to consider that Grimm themselves do not have higher quality measurements of the low end performance of this speaker. They measured the speaker in an anechoic chamber that’s anechoic down to 150 Hz only, hence the simulation of the low end performance in their graphs.

The biggest mystery to me is how other reviewers came up with better measurements. The thing is, we’re not sure how reliable their measurements are. For example the measurements shown below are for the low end done via a ground plane measurement, so not free field. This technique boosts the low end with up to 6 dB.

Audio magazin measured -3dB @17Hz, 105dB max SPL (100dB without compression), 10%THD @40Hz & 100dB

View attachment 452916

This is the type of measurements Grimm refers to in their response "how did you measure the sub? Since it is intended to be used on the floor it must not be measured in free field".

The good news is that most people will also have these speakers on the floor

 

[Geert]

Indeed it looks like they only measured the LS1 without sub here..... My question marks only became larger now..

The anechoic room measurements seems to be done without the sub, probably because that room is not anechoic for low frequencies. But they had the sub for the review since there's a whole paragraph dedicated to how it sounds (subjectively).

 

[Sokel]

The anechoic room measurements seems to be done without the sub, probably because that room is not anechoic for low frequencies. But they had the sub for the review since there's a whole paragraph dedicated to how it sounds (subjectively).

I would discard their measurements if they haven't shown consistency with other speakers as shown in previous posts.
It's indeed strange.

The fact is that listening to them they sound definitely 3-way that goes low. Not high SPL by all means but far from a 2-way at the same room in terms of low and low quality.
The most concerning aspect is the enormous distortion there.

 

[Geert]

The most concerning aspect is the enormous distortion there.

Indeed, but if the company doesn't see a problem with the measurements then it stops I’m afraid. The only remaining question for me is if we received an official response from the right people at Grimm HQ or just from the dealer.

 

[Vuki]

I would discard their measurements if they haven't shown consistency with other speakers as shown in previous posts.
It's indeed strange.

The fact is that listening to them they sound definitely 3-way that goes low. Not high SPL but all means but far from a 2-way at the same room in terms of low and low quality.
The most concerning aspect is the enormous distortion there.

I've listened to them 2x, both @High end Munich show, and they sounded excellent - balanced, dynamic and full range. Loudness was quite high, not home theater high, but very high. I don't believe that sound like that could be achieved with loudspeaker which had bass response attenuating down from 100Hz.

 

[Thomas_A]

Question to @amirm how was the step response generated? Is it separate or from the spin? It does show a quite broad negative peak which confuses me, if this speaker is time- and phase-coherent. I am just curious if there is anyway to see in the data if the sub have some anomaly in phase vs. the monitor.

 

[Vuki]

SB1 subwoofer designers whitepaper

NF measurement of the SB1 prototype, from the whitepaper: