Hi All,
I am looking at buying some studio monitor paired with a MINIDSP HD as do-it-all speaker for the family.
The IN8 look very interesting as they use a coaxial driver that helps with the POWER response in the midrange (Mid to TW Xover) and they seem to have decent LF response compared to the Kef R3 with a similar configuration.
In addition if you factor everything they are rather affordable and compact.
Latter, multiple subs may be added.
I have (mostly) read the thread and decided to have a look at the amount of EQ the IN8 may require and how to design this EQ.
As always, one need to have a close look at the DI to decide what to EQ and what not to EQ.
It is a very interesting exercise.
It is just my first crack at it but i just wanted to share the results as to really do appreciate the effort put into publishing the data, kudos to
@amirm.
This is just theoretical as I don’t own the speaker and one would have to probably add LF EQ for Room compensation.
But again if we start with a “flat and smooth on/off-axis” that’s 70-75% of the Predicted Preference Rating (p464 of
@Floyd Toole book, 1st edition)
- As a starting point I used the LW flat target but doing so up to 16k will result in way too much HF above 5k.
Nothing new just look at the DI again… Also a it seems that one must be cautious around 1kHz.
Similar to https://www.audiosciencereview.com/...udio-monitor-review.10897/page-50#post-379642
- Then I added the PIR target with 9dB drop from 20 to 20kHz, as a preferred target (History of Harman Headphone Target Curve, slide 5 http://www.juloaudio.sk/Umiestnenie_reprosustav/History of Harman Target Curve.pdf)
The equation I used is:
Target_PIR = 99.57-1.31947*log(f);
One can offset the target up and down by changing the 99.57 value, of course without changing the slope (-1.31947).
Note that is does not mean, I believe, that one should compromise the LW/on-axis FR to reach that goal but instead select the speakers (Spinorama data, controlled directivity etc.) that come close to that and then devise the EQ to “polish off” the final result.
- I used Genetic algorithms to fit the LW target from 50 to 5000Hz and simultaneously the PIR target from 40 to 16kHz.
Probably weighting should be applied there but I did do NOT that, just equal weight except for the range limitation imposed on the LW.
Some biquads may be omitted to keep the number compatible with the DSP and leave space for in-room EQ
Also the high Q @5200Hz might be more pleasing to eye than needed especially with the production tolerances.
Proposed EQ:
Type Freq Q GaindB
Highpass: 25.25, 0.00, 1.74,...
Peaking: 168.5, 1.27, 3.89,...
Peaking: 245.0, -1.10, 0.50,...
Peaking: 331.0, 2.50, 4.00,...
Peaking: 1250.0, -1.22, 6.00,...
Peaking: 1905.5, 1.41, 6.00,...
Peaking: 2512.0, -2.36, 4.00,...
Peaking: 2800.0, 1.84, 1.36,...
Peaking: 4734.5, 0.62, 2.00,...
Peaking: 5200.0, 1.61, 11.0,...
Peaking: 6836.0, -1.10, 5.00,...
Peaking: 6856.0, -0.89, 3.50,...
Peaking: 9700.0, 0.73, 2.75,...
Peaking: 9704.0, 1.39, 3.75,...
Peaking: 14825, -0.84, 4.00,...
I decided to boost the LF a bit as the weight of the LF response in the Predicted Preference Rating is 25 -30% (p463 of
@Floyd Toole book, 1st edition). Why not?
The first boosting HighPass Biquad can be omitted but I believe it should be fine since the speaker has built-in limiters/compressors .
It should help when the user is not playing vey loud, the limiter will just kick in earlier when the volume goes up.
Alternatively decreasing the over all sensitivity of the system by 6dB should work but at the price of a lower max SPL.
Not an issue for me as I don’t intend to play loud.
here is the data compared to
@QMuse EQ
https://www.audiosciencereview.com/...udio-in-8-studio-monitor-review.10897/page-40
The output of the optimizer looks very similar to
@QMuse EQ...
And a zoom for the LW and PIR
Please feel free to comment.
Next step:
Directly work on the LW, PIR and predicted rating.
If anyone could point me towards the exact equation that is used
@MZKM I could try.
Cheers All
M