• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

The Joy of the MiniDSP 2x4HD and Real Time PEQ and Crossover Adjustments!

ctakim

Active Member
Forum Donor
Joined
Jan 3, 2021
Messages
125
Likes
138
Location
Menlo Park, CA
So largely from my time on this site I've gotten much more interested in how differences in frequency response graphs correlate with the subjective listening experience. But honestly it was hard to know what was really relevant. Lots of reviews on ASR are critical of a jagged frequency response curve but what does that mean to the listener? Clearly many speakers manufacturers consciously choose to NOT have a perfectly flat speaker FR (looking at you B&W) while others strive for this with superhuman efforts (Genelec anyone?). And the eminent Dr. Toole tells us that a flat FR curve corresponds to the highest rating in double blinded listening tests, while others emulate a different target FR curve or swear by the Harman House Curve, for instance.

So in the last few weeks I bought a MiniDSP 2x4HD (and a UMIK-1 microphone, too) and set it up with my computer desktop system which consists of a MacMini with USB output to the MiniDSP 2x4HD with 3 analog outputs: stereo R+L to a Loxjie A30 AMP and Sub to my REL T71 (no snarky comments please). My music source is Roon with my own personal ripped CD collection and Qobuz. The stereo AMP is connected to a 4 way Monoprice speaker switch and I current have 3 pairs of desktop speakers that I can cross compare (it is a big desk). These are a Roger LS3/5a purportedly from the early 1990's (11 ohms) version, DIY CSS P215, and SoundArtist LS3/5a knockoffs. The Monoprice unit allows me to rapidly toggle between each of the speakers, but no, this is not a blinded listening comparison.

What has been a revelation is the ability to adjust the crossover and tweak the FR using the PEQ software in realtime and to listen what impact it has on the sound quality while sitting realtime. Hmm, these speakers sound bright but shallow, the other ones sound more muted in the high end. What contributes to that and how can this be adjusted, augmented and improved? Let's boost this speaker's FR at 2000Hz and above by 3 dB and hear the difference in sound. I'll have more to say about my actual in room measurements with the UMIK-1 and REW 5.1 at a later date but I am having blast with all of the above. So thanks to Amir and ASR for reconnecting me to my love of high fidelity and for introducing me to the technology that has supercharged things in ways we could never had anticipated 20+ years ago.
 

Lorenzo74

Senior Member
Joined
Nov 17, 2019
Messages
320
Likes
264
Location
Italy, Rome
So largely from my time on this site I've gotten much more interested in how differences in frequency response graphs correlate with the subjective listening experience. But honestly it was hard to know what was really relevant. Lots of reviews on ASR are critical of a jagged frequency response curve but what does that mean to the listener? Clearly many speakers manufacturers consciously choose to NOT have a perfectly flat speaker FR (looking at you B&W) while others strive for this with superhuman efforts (Genelec anyone?). And the eminent Dr. Toole tells us that a flat FR curve corresponds to the highest rating in double blinded listening tests, while others emulate a different target FR curve or swear by the Harman House Curve, for instance.

So in the last few weeks I bought a MiniDSP 2x4HD (and a UMIK-1 microphone, too) and set it up with my computer desktop system which consists of a MacMini with USB output to the MiniDSP 2x4HD with 3 analog outputs: stereo R+L to a Loxjie A30 AMP and Sub to my REL T71 (no snarky comments please). My music source is Roon with my own personal ripped CD collection and Qobuz. The stereo AMP is connected to a 4 way Monoprice speaker switch and I current have 3 pairs of desktop speakers that I can cross compare (it is a big desk). These are a Roger LS3/5a purportedly from the early 1990's (11 ohms) version, DIY CSS P215, and SoundArtist LS3/5a knockoffs. The Monoprice unit allows me to rapidly toggle between each of the speakers, but no, this is not a blinded listening comparison.

What has been a revelation is the ability to adjust the crossover and tweak the FR using the PEQ software in realtime and to listen what impact it has on the sound quality while sitting realtime. Hmm, these speakers sound bright but shallow, the other ones sound more muted in the high end. What contributes to that and how can this be adjusted, augmented and improved? Let's boost this speaker's FR at 2000Hz and above by 3 dB and hear the difference in sound. I'll have more to say about my actual in room measurements with the UMIK-1 and REW 5.1 at a later date but I am having blast with all of the above. So thanks to Amir and ASR for reconnecting me to my love of high fidelity and for introducing me to the technology that has supercharged things in ways we could never had anticipated 20+ years ago.
I enjoy my DDRC24 even more…
 
OP
ctakim

ctakim

Active Member
Forum Donor
Joined
Jan 3, 2021
Messages
125
Likes
138
Location
Menlo Park, CA
I enjoy my DDRC24 even more…
How are you using it and what has it done for your system? Also, part of the reason I got the 2x4HD is because you can add Dirac Live and upgrade to the DDRC24, which I plan to do at some point. But I thought I would do this stepwise and playaround with things so help me understand what was going on. But I will, no doubt, purchase DIRAC Live for this unit. But in the meantime, I will see what I can do with REW and the MiniDSP 2x4HD!
 

richard12511

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
4,011
Likes
5,773
Dr. Toole tells us that a flat FR curve corresponds to the highest rating in double blinded listening tests, while others emulate a different target FR curve or swear by the Harman House Curve, for instance.

Just to be clear, the "flat FR" curve that Dr. Toole recommends and the "Harman House Curve" are essentially the same, but measured differently; anechoic for the former, in room for the latter.

Dr. Toole definitely doesn't recommend a flat FR in room. Such a curve will likely sound too bright. Dr. Toole recommends a Harman house curve, but the slope of that curve depends on many things.

Do you have the ability to measure with REW(Room EQ Wizard)?
 
OP
ctakim

ctakim

Active Member
Forum Donor
Joined
Jan 3, 2021
Messages
125
Likes
138
Location
Menlo Park, CA
Just to be clear, the "flat FR" curve that Dr. Toole recommends and the "Harman House Curve" are essentially the same, but measured differently; anechoic for the former, in room for the latter.

Dr. Toole definitely doesn't recommend a flat FR in room. Such a curve will likely sound too bright. Dr. Toole recommends a Harman house curve, but the slope of that curve depends on many things.

Do you have the ability to measure with REW(Room EQ Wizard)?
Yes, just starting to play around with REW and the UMIK-1 for making in room measurements. And thanks for pointing out the difference between anechoic and in room FR curves. That is an important point.
 

puppet

Active Member
Joined
Dec 23, 2020
Messages
149
Likes
104
How are you "adjusting the passive crossover" with the mini? Unless you've bypassed the loudspeakers network and are using the mini's programming you're not doing anything except screwing up the frequency response. That mini is a 2-way processor. The original network has to be disabled if you're redoing the crossover. Then, both the drivers, (2) each loudspeaker x (2) loudspeakers, will need their own amplification (L and R) so, (4) channels.
 
OP
ctakim

ctakim

Active Member
Forum Donor
Joined
Jan 3, 2021
Messages
125
Likes
138
Location
Menlo Park, CA
How are you "adjusting the passive crossover" with the mini? Unless you've bypassed the loudspeakers network and are using the mini's programming you're not doing anything except screwing up the frequency response. That mini is a 2-way processor. The original network has to be disabled if you're redoing the crossover. Then, both the drivers, (2) each loudspeaker x (2) loudspeakers, will need their own amplification (L and R) so, (4) channels.
I think you are two steps ahead of me. I'm just adjusting the crossover between the sub and the 2-way bookshelf speakers. I'm not doing a digital crossover between the tweeters and the woofers in the bookshelf speakers. Only the Rogers LS3/5a has dual driver inputs that could allow for a biamplifier set up that would ultimately allow for a within speaker digital crossover. So effectively, I'm just making digital adjustments for the subwoofer the same that you can do by getting down on the floor and changing the settings on the sub amplifier. Plus I can also use the high pass filters to control what I send to the main units.
 
Top Bottom