GRIMM Audio LS1c & SB1 DSP Speaker Review

[Wesseling Audio Lab]

All of my passive speakers have the ability to slope the in room response in order to adjust the relative bass level. 3 way requires two external resistors(one mid, one high) to be changed together to maintain a reasonably flat response.

I did an experiment with my 2 way that has a 2" broadband driver crossed at 700hz. This speaker has the attenuation resistor external for easy swapping.
Only by ear and over a 3 day period, I changed the resistor until I was satisfied with the balance. I then listened for weeks with many recordings and continued to be comfortable with the relative bass level. At this time, and only at this time I took a measurement and lo and behold it measured 5db down at 10khz with a very flat slope.

The speakers in this review should have this user adjustment - Lynn Olson said it decades ago, all speakers need BSC for the end user.

 

[Wesseling Audio Lab]

It does strike me that the measured results are almost exactly what you'd get from a 10" sub driver in that enclosure size (15L or 0.5cubic feet?) with no DSP to boost the low end. f3 of 50Hz, f10 30Hz.

Yes to the rolled of low end, but under volume box typically produces a high Q which also requires DSP

 

[olieb]

Anyway, who in the world would buy a 40k speaker and *not* equalize at least the bass to taste?

Absolutely.
The system seems to have a lot of options to do that.
But I still have a question here.

Further up the thread Amir explained this.

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.

I am not sure I understand it fully. You tried different options of the NFS for measuring long wavelengths?
Did you fiddle with the bass adjustments of the LS1 too? Or did you use the system as provided? Or else?
Was there no option to get more (sub) bass from the speaker?

 

[Wesseling Audio Lab]

I'm curious about the sub box alignment. Did someone identify the woofer used - I would try and investigate a few things.

 

[Sokel]

Asked my dealer about it, he carries those too.

By what Amir has measured there's definitively something amiss with settings.
The speaker is set-and-forget, so if the last reviewer/rep/whoever had set it up with anything other than 20Hz low cut it would carry that setting unless it would be changed.

The 100Hz and 40Hz low cut settings when "Grimm" sub has been chosen in the settings does NOT disables the sub, only lowers output and slope.

 

[Heinrich]

Changed my vote temporarily. The bass cannot be treated with a full-fledged DSP, especially parametric e/q is missing. O/k you could do that at the source, but!

Read the manual (page 45 ff), and the reasoning on why the DSP is deemed no good (page 9: "Some companies apply DSP for ’room correction‘. We rather not use DSP in the LS1 for this since the effects are influenced by the position of the listener.")

I also think there is excessive pedantic) DSP with Dirac seen way too often. To not offer DSP to even the knowledgable customer ("What is the square root of -1?"), paying qualifying 40 grand, is a bit over the top. Shrugging shoulders here. (Despite all my sympathy because of my own DIY efforts put in wide baffles.)

 

[Vuki]

Nope. Do you think an FFT is a simulation of a real time analog signal? That is also a computed result based on time domain samples and subject to variation by picking its length.

To the extent FFT finds the basis sine waves, NFS finds the (3-D) Henkel functions to describe the sound field. Neither it, nor FFT computation fall in any kind of simulation domain. Just because complex computations are needed to convert sample data to graphs that we like to see (understand), doesn't mean the result is simulated.

Now, if you took some hand created data and fed it to NFS, sure, that would be a simulation. But that is not the case. NFS in my measurements uses 1000 to 2000 sweeps to compute its final results. The data presented is simply the 3-D representation of that 2-D data.

Simulation, approximation, extrapolation, interpolation...whatever.
It is not really done in anechoic environment, it's a construct.
And I'm sure it is correct and it's really great tool.
But what is more important is that all other measured frequency responses of this loudspeaker are wrong but yours is correct?
And you are not even a little bit suspicious that maybe something went wrong? DSP setup or whatever...
How do you explain that above shown stereoplay/audio measurements of KEF and Genelec are almost identical to NFS' but Grimm LS1 is so much off?

 

[Vuki]

That's the point here on topic: You need to equalize the response of the LS1 anyway, at least in the bass, to what you may find at home in that particular situation. I really do not understand why there is so much fuzz about it. As if us never bought a speaker, get it home and optimize to our needs, to find vast deviation from the prediction. Well?

The fuzz is because: "look at these mfs - they charge so much and there is no bass! I'd rather buy Magico/Revel/B&W/Kef..."

 

[Heinrich]

The fuzz is because: "look at these mfs - they charge so much and there is no bass! I'd rather buy Magico/Revel/B&W/Kef..."

Simulation, approximation, extrapolation, interpolation...whatever.
It is not really done in anechoic environment, it's a construct.

"Measurement" - I know, one is tempted to relate one against the other to find which is better and so forth, then you know where to carry the money.
If you want to evaluate a non-trivial technical machine, such an attempt may be too weak. Not only is the machine multi-faceted, but those measurements implicate, as I said before, a model, a constructed, made-up model, a mental map of the thing in question. I described the intellectual challenge extensively above. It is the very wrong place to teach people, hence I better full stop.

 

[Purité Audio]

Simulation, approximation, extrapolation, interpolation...whatever.
It is not really done in anechoic environment, it's a construct.
And I'm sure it is correct and it's really great tool.
But what is more important is that all other measured frequency responses of this loudspeaker are wrong but yours is correct?
And you are not even a little bit suspicious that maybe something went wrong? DSP setup or whatever...
How do you explain that above shown stereoplay/audio measurements of KEF and Genelec are almost identical to NFS' but Grimm LS1 is so much off?

Klippel measurements have been corroborated by more traditional methods multiple times and found to be accurate.
In direct comparison the LS1s never had the weight or bass extension of say the 8Cs, I thought of them more suitable for the classical listener.
Keith

 

[Vuki]

Klippel measurements have been corroborated by more traditional methods multiple times and found to be accurate.
In direct comparison the LS1s never had the weight or bass extension of say the 8Cs, I thought of them more suitable for the classical listener.
Keith

I don't doubt in Nfs but in @amirm measurement setup

 

[Purité Audio]

You can compare Amir’s measurements with Erin’s and with Stereophile’s for yourself,

KEF LS50 Meta Bookshelf Speaker Review

Kef LS50 Meta

www.erinsaudiocorner.com

KEF LS50 Bookshelf Speaker Review

This is a review and detailed measurements of the famous KEF LS50 speaker. It was kindly loaned to me by a local member. The LS50 costs US $1,500 but seems to be on sale for US $1,300 on Amazon and elsewhere. The LS50 nails the look of the speaker with the bright color and shape of the...

www.audiosciencereview.com

KEF LS50 Meta loudspeaker Measurements | Stereophile.com

Sidebar 3: Measurements I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the KEF LS50's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. My estimate of the LS50 Meta's voltage sensitivity was...

www.stereophile.com

Keith

 

[olieb]

In direct comparison the LS1s never had the weight or bass extension of say the 8Cs, I thought of them more suitable for the classical listener.

Interesting, so the attenuated bass is some kind of signature of the LS1?
What prevents me from dealing up or EQing the subwoofer for more (or at least "flat") bass response?
I like to have the "right" amount of bass for classical music too.

 

[Davey]

What prevents me from dealing up or EQing the subwoofer for more (or at least "flat") bass response?

Nothing.

You have a substantial 10" driver in a way too-small box. A lot of power and a lot of EQ is required. 'Very easy to understand that aspect of the system.

Potential customers might quibble about the relative integration to the main speaker. But it certainly can be altered if not to a persons liking.

 

[Purité Audio]

Generally not advised to boost bass and indeed with the 8C the amount of bass boost is limited,
I would have to check but I don’t believe the LS1s have that provision, I remember there was an adjustment for the severe toe in option, Grimm aren’t keen on DSP hence ( I believe) the refusal of the Kii prototype .
Keith

 

[kharan]

That's not a crazy tuning, the Revels F328 Be have notably restrained bass levels too to take advantage of room gain.

Of course, that also means a lot of people will find them bass shy. Bass levels is much a matter of personal preference.

 

[Wesseling Audio Lab]

This is how I would do it, front ported! All of that space available for box volume.

 

[Robbo99999]

That's not a crazy tuning, the Revels F328 Be have notably restrained bass levels too to take advantage of room gain.

Of course, that also means a lot of people will find them bass shy. Bass levels is much a matter of personal preference.

That's true, but if you're gonna use some RoomEQ then you don't really want the bass rolling off because you can use the extra bass (from the linear extended bass of other speakers) along with room gain to EQ up the dips (so to speak) by just cutting the peaks, so the argument for rolled off bass is only really useful if you're not gonna be using somekind of RoomEQ.

 

[markstein]

I also think that such a speaker should be linear down to the very low bass, assumimg that users will use PEQ to manage room gain, standing waves etc.

Either the measurement is wrong for some reason, or the subwoofer is absurdely overprized IMO.

Voted great due to the "suboptimal" pricing.

 

[Vuki]

You can compare Amir’s measurements with Erin’s and with Stereophile’s for yourself,

KEF LS50 Meta Bookshelf Speaker Review

Kef LS50 Meta

www.erinsaudiocorner.com

KEF LS50 Bookshelf Speaker Review

This is a review and detailed measurements of the famous KEF LS50 speaker. It was kindly loaned to me by a local member. The LS50 costs US $1,500 but seems to be on sale for US $1,300 on Amazon and elsewhere. The LS50 nails the look of the speaker with the bright color and shape of the...

www.audiosciencereview.com

KEF LS50 Meta loudspeaker Measurements | Stereophile.com

Sidebar 3: Measurements I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the KEF LS50's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses. My estimate of the LS50 Meta's voltage sensitivity was...

www.stereophile.com

Keith

Thank you. I didn't realize I could do that. If you have already done that, what is your conclusion?