I just found a guide from MiniDSP on how to interactively equalize headphones using their E.A.R.S. measurement rig. I tried this out with my LG V20 and USB Audio Player Pro (UAPP), and I’m frankly blown away.
The basic idea is this:
Generate some full-spectrum pink noise with Room EQ Wizard (REW) and load it onto the player
Set the volume to your usual listening level (ignore the 80-84 dB recommendation in the guide, you want to EQ for the level at which you listen)
Place the headphones on the rig
Fire up the Realtime Analyzer in REW. I’d never used this before, it’s neat!
Play the pink noise and look at the frequency response
Now fire up the parametric EQ in your player and start tweaking to bring down major peaks and raise major valleys to get closer to a flat line. With a touchscreen EQ like on UAPP, this is easy and kind of fun, as you can see the results in real time in REW!
That’s it! According to their desktop EQ guide their headphone correction curve
is similar in intent to the “preferred headphone target response” identified by Olive, Welti and McMullin (Ref. 1) but adapted for the EARS.
So in theory, this gets my headphones close to the Harman target* using a very intuitive and painless process.
I’ve already created EQ profiles for my LCD2C, DT 1990 and HD 600. I’m going to have to spend a lot of time with these profiles to really understand what they’re doing for me, but I have two fairly strong initial impressions:
I’ve developed fairly strong opinions on the relative merits of my LCD2C and DT 1990. After EQ’ing them both to a similar overall frequency response, I can tell that I’m going to have to seriously reevaluate those opinions. Like right now, I’m listening to Beethoven’s 5th which I didn’t used to think was really in the LCD2C’s wheelhouse, but it sounds sublime!
The HD 600 was already pretty close to the target but needed to be brought down at around 4.2 and 7.7 kHz. Even now that it has a fairly similar frequency response to the DT 1990 and LCD2C, it still sounds clearly inferior to me (grainy and congested). I guess those qualities are not a result of its frequency response–I’ll have to see how it does with a tube amp
* I emailed MiniDSP and they confirmed that
Indeed it would be close to the Harman curve with some tweaks.
So, not exactly the Harman target, but in the ballpark I guess.
I have been using Sonarworks Reference 4 for neutralizing headphone curves for the past year and I can’t listen without it. I mostly do professional use listening and find that the translation to speakers is almost spot on once any pair of headphones issues have been corrected.
The HD 650 is probably one of the flattest most accurate headphones I’ve yet to see and hear, not surprised to see your results here with the 600.
I listen mostly with a pair of Beyerdynamic DT880 Pros 250 Ohm version. It’s a great half open headphone that I feel the high end is on par with Stax and much better than Audeze. But once the correction filter is active the low end really comes back and the resonant peaks in the high end go away completely. I highly recommend checking out Reference 4 from Sonarworks for anyone who is interested in experimenting with headphone correction.
The problem with sonarworks is that they provide a correction that was created using measurements of several pairs of the same headphones - which is better than just measuring one pair, but will never be as good as measuring the pair you actually have. This is because every pair sounds slightly different due QC issues, a change in the manufacturing process or materials, etc.
Just as an example, my friend got himself a brand new pair of HD6XXs and out of curiosity I used my E.A.R.S rig to measure them, and my HD650s. The two had some pretty noticeable differences! Noticeable enough that we could easily tell between the two in blind AB testing as well. In my specific example, I assume the differences were due to my HD650s being over 10 years old, and the 6XXs having pads that were significantly firmer (perhaps just due to the fact that it was brand new)
Yeah, I’ve tried Sonarworks True-Fi as well as Toneboosters Morphit and with supported headphones I do think I generally liked the result. I find that the DIY EQ approach has a few key benefits though:
Works with any headphone. My preferred headphones are the LCD2C and the DT 1990, neither of which was supported by these programs when I tried them (though Sonarworks supports the DT 1990 now)
Works with my specific flavor of headphone. Audeze in particular is known for unit to unit variation, so I like the idea that my compensation is specific to my exact headphone and even my playback chain (DAC/Amp). Sonarworks does offer an individual calibration service which could be handy for someone who can’t do their own measurements.
Is targeted to my preferred listening volume (equal loudness contours and all that).
Targets the Harman response, which I think I prefer for enjoyment listening. It’s not entirely clear to me what curves Sonarworks and Toneboosters target, but since they seem focused on mixing I suspect they might be targeting something a bit different.
Doesn’t require special software to be installed. The output of the REW calibration is just parametric EQ settings, so anything with a parametric EQ can be used (e.g. my LG V20, Roon, etc.)
Remains more tweakable. I know that True-Fi offers an age-based adjustment (presumably for treble) and a bass adjustment, but with custom EQ I keep more options.
Honestly, rather than folks selling proprietary software, it would be really neat to see a service where you can just send your headphones and that returns multiple calibrated EQ profiles (Harman target, diffuse field, etc.) in the form of EQ settings and convolution files, ideally at a several different SPL levels.
On a side note, if anyone’s in or near Austin and wants to try doing this with their headphones, I’m game for having a little measuring and EQ meet.
This is fascinating. I’ve often thought about adding some kind of active EQ to my regular HiFi system, but normally just cut out tone control entirely. I’m aware that DSP has been getting better and better. I’d appreciate a general post discussing DSP and EQ for the near-beginner, including something about equipment.
I see the EARS hardware is about $200. I already have a Mac Mini (portable enough) and a BLUE snowball to help it hear things. Would I need a better Mic? (for Room EQ, not headphone).
What about the complexity for general use of storing multiple EQ profiles on the iphone? I assume you’d need different ones if you process the source through a DAC and/or headphone amp? How much of a project is it to get going intelligently in this direction?
DSP is a huge topic. Perhaps an introduction to the breath of the field w.r.t. to audio along with links to further resources would be useful?
Regarding room correction, it’s not something I’ve done myself but I have a passing familiarity with it. Some salient points:
The basic process consists of measuring your space, generating corrections (usually resulting in parametric EQ settings), applying the settings to your chain and repeating the process until you’re either happy with the measurements or too tired to continue. One way to do the measuring and correction is with REW and MiniDSP offers a guide On how to do this.
To perform the measurements you need a calibrated microphone. I don’t know that it needs to be good, but its own frequency response needs to be known. MiniDSP sells [one such mic](miniDSP UMIK-1 USB Measurement Calibrated Microphone https://www.amazon.com/dp/B00N4Q25R8/ref=cm_sw_r_cp_api_i_5HAhBbV76TM7J)
You have several options for applying the EQ to your chain. If available in your playback software (e.g. Roon) I would start with that. What are you using to feed your HiFi system? MiniDSP also sells standalone DSPs that do this, and as I suspect you’re thinking you can probably turn a Mac mini into a standalone DSP with the right software.
I’ve done room correction with SONOS, in a room where that’s what we decided to pay for. Very simple, and it has calibration information for most iphone/ipads. I would think that the Blue mics are well known enough that calibration information would be available.
I do have the Neutron player on iOS, which has a plethora of EQ options from 4 to 14 bands. I tend to feed my Hi-Fi differently than my phones. Phones get streaming input, either from Apple Music or from higher res or FLAC files sitting on a network computer with media server software.
The Hi-Fi tends to get vinyl via a VPI Prime Scout, Ortofon Bronze, Musical Fidelity phono preamp, Wyred4Sound STI-1000 integrated amp. Alternatively, it can be fed with an older Rotel 900 series CD player (Burr Brown DAC chips, or TOSlink to a TEAC DAC (UD-H01)), or if I must stream, a Sonos Connect digitally output to the TEAC DAC.
I’d considered getting DSP in a stand-alone component that came with measuring software. Maybe that’s old-fashioned now.
I don’t use Roon or Tidal, as I usually listen to Vinyl or CD on the speakers. And need to think before I subscribe.
Nice! Sounds like you would need a standalone DSP then. If your DACs matter to you, the one challenge might be finding a 100% digital solution that you can plug in before your DAC. Stuff like this will do its own digital to analog conversion.
Thanks! Space and complexity get to be a concern. I’ve been very happy with the Wyred4Sound integrated amp, and have thought that they offer a good price/performance ratio. I’ve strongly considered both their music server and their DAC-2, and may make that kind of move if/when they come out with revisions/upgrades.
Can you share what an approximation of the Harman target for HD600 in Roon would look like? I have no measurement gear whatsoever and have been going by what I hear.
Below is the result of running the automated correction in Room EQ Wizard. Note that based on my settings, this leaves the bass alone (which is well below the Harman response, but I didn’t want to mess with it because the distortion is already high). This may not be exactly what I listened with originally, but I deleted my EQ profile because I’ve since gifted my HD 600 to my brother in law.
If you want to play with this in Room EQ Wizard yourself, you can find my work here. The specific measurements file you want is this one.
Awesome, thanks. So if I’m understanding that picture correctly, it’r applying those changes at those given frequencies? Also, I don’t have an EARS rig. Will a blue Yeti microphone work for using Room EQ Wizard?
Yes, in the picture you’ll see 6 channels of corrections. In this case they’re all PK filters (called “Peak/Dip” in REW). You’ll probably want to make some tweaks based on listening, but this should give you a decent starting point. Basically it’s toning down peaks at around 4.7, 8.3 and 16 kHz, and filling in a dip at around 6 kHz. I’m pretty sensitive to sibilance, so for me the most impactful would be the filter at 8.3 kHz. From what I remember, lowering the peak at 4.7 may help a little with instrument separation. I might actually leave the dip at 6 alone for the same reason.
Also, you’ll want to apply about 6 dB of headroom management in Roon since this profile does boost some frequencies by up to 5.5 dB.
I don’t think so. You need a calibrated microphone with a known frequency response, and AFAIK such calibrations are not available for that mic (but I’d be happy to be wrong about that!). For measuring headphones, you’ll also need some sort of rig on which to place the headphones. You could build such a thing (most easily as a flat-plate coupler), but the nice thing about the E.A.R.S. is that it a) does some ear simulation and b) is used by other people in the exact same form so makes it possible to compare measurements.
Thanks for the explanation. I’ve applied the settings in the picture, and I like it so far. I did feel the need to boost bass a bit, so I added a broad boost at 20hz and 35hz of 4 and 2 db, roughly. Seems to help round out the sound.
Ah bummer. Maybe I’ll get one eventually, once I get into serious measurements, etc. For now I’m pretty happy with some basic tweaking.
