Grimm Audio white paper - why they chose wide & shallow cab, and employment of DSP, LR4th order...

tajanes

Obviously take any company's white paper for what it is, but there are some interesting bits of info, imo, in this one. A few being; even though theirs is a two-way, why target having mids handle 300Hz+, wider baffle advantage (rel to vocal frequency range), discussion / rational of placing tweeter below woofer in box design. And for those implementing DSP, a few good practices.

Ed_Perkins

A lot of good info on how to use DSP correctly, especially on why you shouldn't try to EQ every driver anamoly flat.

rjj45

Interesting that Bruno has moved on to Purifi and that their speakers do not follow much, if any of the principles described in the white paper.....

Ed_Perkins

The wide baffle look of the Grimm speakers probably had a very low WAF factor. What's the use of a speaker with technical advantages if it doesn't sell? The DSP info does apply to all speakers though.

tajanes

Following on speaker baffle width, if my math is correct 300Hz baffle step ~ 14.4 inches, to avoid lower-end of voice reproduction range their spkr is 20.4 inches and full rounded sides.

I'm sure (Bruno's move) it has nothing to do with the money... ha
I see he is listed as the 'inventor' of the Ncore class D amp, not sure who designed the GAudio speaker, but still interesting.

tajanes

@Ed_Perkins said:
The wide baffle look of the Grimm speakers probably had a very low WAF factor. What's the use of a speaker with technical advantages if it doesn't sell? The DSP info does apply to all speakers though.

To ~borrow from Billy Crystal> To sound or look marvelous...that is the question!

But I'd have to begrudgingly agree, my maggies and open backs have been replaced by more 'acceptable' speaker builds. But the addressing of the voice range integrity, via either baffle step / baffle width and (not per Grimm's research paper) placing a crossover in the highest frequency sensitivity range (where most tweeters are filtered) are issues worth considering in box build and Xover designs.

charlielaub

I heard these speakers at AXPONA earlier this year and they were not bad but I didn't think they were super special. IIRC the company targets recording studios, and the shape of the speaker works well close to walls, etc. because it is not very deep.

Their DSP subwoofer is executed pretty well, however, that is not covered in this whitepaper.

tajanes

@charlielaub said:
IIRC the company targets recording studios, and the shape of the speaker works well close to walls, etc. because it is not very deep.

Voicing to venue... ie With Iowa coming up, maybe time to re-voice based upon the general auditioning placement of speakers well out from the back wall (and side walls for that matter).

Steve_Lee

@Ed_Perkins said:
A lot of good info on how to use DSP correctly, especially on why you shouldn't try to EQ every driver anomaly flat.

Isn't this where voicing comes into play? Even with DSP I find a completely flat FR to lack je ne sais quoi.

tajanes

@Steve_Lee said:

Isn't this where voicing comes into play? Even with DSP I find a completely flat FR to lack je ne sais quoi.

À tes souhaits ....ha, jk Agreed

Steve_Lee

Merci, mon frère an audio . . .

Ed_Perkins

About my statement "A lot of good info on how to use DSP correctly, especially on why you shouldn't try to EQ every driver anamoly flat."

I was referring to a common DSP practice to "hammer" a driver's response flat around the crossover point and then apply text book crossovers. The Grimm paper points out that some driver anomalies (e.g. dips) are best left untouched. I wasn't referring to the overall response.