Objectivists board room

Discussion in 'Sound Science' started by joe bloggs, May 28, 2015.

  1. castleofargh Contributor
    I have no idea what you're talking about, now if you'll excuse me I need to go and hide 6 of my 7 DAPs to pretend like I'm a normal audio consumer. :sweat_smile:
    JaeYoon likes this.
  2. reginalb
    I've hidden several from myself. I haven't seen my first gen iPod Shuffle in ages - probably got thrown away when I moved at some point?

    I was just thinking about everything I've either broken and tossed or just sold away.

    Don't know where they are:
    iPod shuffle first generation
    iPod shuffle 4th generation
    Zune HD
    iPod Touch first gen
    iPod 3rd gen
    Philips GoGear something or another that looked like a Clip

    HifiMan 601
    HiFiMan 602
    iBasso DX50
    Sansa Clip+
    Sansa Fuze+
    Astell&Kern AK300

    At my desk:
    iPod Shuffle 4th gen
    HiFiMan 801
    Sony ZX1

    And my whole music collection is on my cell phone (I only own about 70GB - owing to streaming). But since becoming a regular over here at Sound Science, I feel like I went in to rehab. I mean, I still buy them, but for different reasons now, which is alright...I guess? I'm no longer buying a HiFiMan 601 thinking I'm getting way better sound quality. Now I know that I'm just being silly. And there are people over in the other sections of the forum that would put that list to shame (probably one or two here would as well). The guy that posted about us having a problem was on to something.
    Last edited: Nov 6, 2017
    JaeYoon likes this.
  3. bigshot
    I have 8 iPods, but since I got a micro SD card reader for my iPhone, I only use one of them (in the car). I love my iPods though and they are all loaded with different types of music. I pull them out for parties and plug them all in on random shuffle, so I can "switch channels" on genres of music easily on the fly.
  4. orderingrabbits
    Of course. I'm asking in relation specifically to low distortion headphones, where THD+noise stays below 1% across the board at much higher than listening volumes - that is, where there is enough headroom to use EQ without THD becoming a problem.

    Right, this does happen very often. People use the crappy little iTunes 5 bar EQ and declare all EQ is awfule, despite never using a real parametric equalizer. With properly used digital EQ, clipping is a complete non-issue at any part of the signal chain excluding the transducers themselves.
    I'm curious about which filters do what, in terms of pre-ringing and post-ringing and audibility.

    Some roll-off, even some really bad cases, can definitely be compensated for by EQ although ultimately it does depend heavily on your listening volume.

    Hence why I came here to ask :)

    Yep, same. I find all headphones benefit heavily from EQ.

    I didn't expect to. Subjectively, the benefits of EQ do outweigh any potential downsides (not that I've noticed any - which is why I came here to ask).
  5. headwhacker
    The ipod classic still beats most of the modern DAPs in overall experience. With basic DIY skills, you can get a bigger battery and slap a larger storage. 2TB is possible. You can go for weeks without needing a charge while the ipod is playing music at least 8 hours a day.
  6. Argyris Contributor
    My OG iPod Video served as my main portable player for over seven years of nearly daily use. The last several of those it used Rockbox, which vastly increased its capabilities, at the expense of interface simplicity and aesthetics and probably battery life. Back in 2014 or thereabouts (after it had been retired in favor of a Clip Zip) I restored its original firmware, and thus it remains today.

    In fact, it still holds at least a few hours worth of charge and remains the only portable device I own which can power my HD 600 to solid volume. Alas, while it's a miracle that it can hold any charge whatsoever after so many years of heavy use, nonetheless it doesn't last nearly long enough anymore to become my primary music source again. Not to mention, by modern standards it's a thick and heavy brick, its screen is badly damaged (lots of random pixels are stuck on--interestingly enough, these are only visible when the backlight comes on) and it's inconvenient having a separate music player plus my phone in my pocket all the time.

    I keep saying I'll get a new battery and screen for it and convert it over to CompactFlash, but I feel like I just wouldn't use it enough to justify the expense. It'd probably be a fun project, though.
  7. castleofargh Contributor
    I'm sort of your guy for this as I usually set up my preferred EQ by ear without too much regard for what should or shouldn't be done. then run REW with my EQ in the loop ON and OFF to confirm that I'm in the proper area and that a little less or a little more amplitude wouldn't have too massive an impact on some distortions, or create some loud ringing(although unless it's in the low end I usually notice that by ear). by ringing here I'm talking about the transducer ringing too much too long. not really about the phase ringing caused by the type of EQ, which is usually peanut compared to a driver having damping issues. but the only conclusion I can really stand by is that it really massively depends on the gear used and what I'm trying to achieve.
    I can make screen shots of some of the IEMs I've measured(what I'm interested in changing the most), but obviously those measures I kept are for my final EQs so they won't show barbaric destruction of anything. I guess I could try a few extreme EQs and measure that, but I'm soooo lazy ^_^.

    if you have an EQ with options for linear vs minimum phase, you can test for yourself what, if anything, turns out noticeably different. while you have an entire group of audiophiles pissing themselves about how bad pre ringing can be at the low pass frequency(ultrasounds) of some formats or DACs, it is actually pretty easy to test things for ourselves and see that even in the mid range most of the time the impact is really nothing to be afraid of.

    while clearly reaching outside the usage you and I can have EQing a stereo signal, I remember this video as making a lot of good points. and most of all, the guy making those videos isn't taking any audiophile side pretending that one option is amazing while the other is pure evil.

    oh in case it isn't clear, here is a pulse showing absolutely worst impact possible from both filters
    top is minimum phase, and bottom linear. you get this result by removing a huge chunk of the signal content that had an infinite range of frequencies, and cutting all the higher part off. it is a good way to imagine what is going on with phase, but a stupid way to imagine what's happening to usual audio signal as audio signal has already very very low energy/information in the ultrasounds so filtering it out never creates that mess. and in our use of EQ, we don't brick wall filter, so the effect is actually close to being irrelevant for moderate EQ uses.

    a case could be made that headphones behave mostly as minimum phase so that's what makes more sense most of the time for EQ. but even while I'm writing this, I'm annoyed by the oversimplification and what it could do in the wrong hands ^_^. a direct counter example to this IMO would be that minimum phase tends to move the "image" forward or backward as we apply the EQ, while linear phase can be perceived as more stable. of course those stuff also matter a lot less depending on the frequency where the EQ is applied.
    ideally we could think of taking the headphone's phase when it's not flat, and use EQ to flatten it. we can play a lot but in the end I find that I'm EQing to my subjective preference and all the objective aspect tends to take a step back as long as I enjoy what I'm hearing.

    worth mentioning too: I'm clearly a noob trying a lot of stuff by himself for himself, if you want real professionals telling you about EQ, I'm not the guy.

    indeed. the distortions we get at a given frequency are ultimately a matter of the headphone/amp, and the volume output of the signal. but if something goes down 20dB in the low end, and already has some fairly massive distortions, chances are that boosting by 20dB is not going to improve the distortion situation(for a lot of potential reasons).
    to be clear, I often end up with improved measurements after EQ, but this happens mostly when done precisely and moderately. I can't advise people to try and fully compensate huge roll offs with massive EQ boosts. in general that's not a recipe for fidelity. personally I would always advise to get a headphone with too much low end or too much trebles, and EQ that down. often the results can become really good.
  8. orderingrabbits
    I do this a lot too, although that might change once I decide whether or not to purchase the minidsp dummy head.

    What's the most extreme EQ you have? Just an approximate dB change would be fine.

    I use pulseeffects and equalizer APO and I have no idea whether either of them is minimum or linear phase. Any suggestions for system-wide EQ which lets you switch?

    I have done not a 20dB boost, but a 15dB boost with the HE-400i. As it was a low distortion headphone throughout, and my listening volume never exceeds 80dB or so, the result was pretty decent. I didn't like that headphone though, the bass was super anemic even compared to HD600s and the treble was just all over the place. Thanks for the video, I've seen an article which covers the same thing but not nearly in as much detail.
  9. castleofargh Contributor
    are you @Joe Bloggs secret little brother from another dimension?

    my most extreme EQ must be some of the Xfeed convolution stuff I try. when adding up correcting a headphone, and applying some fake HRTF changes, sometimes the amplitudes can become a little crazy. else purely EQ, I don't think I have anything above 10dB and most of the time I'm more realistically below 6db. now one thing to account for is that I'm in my own bubble. I get IEMs already based on the FR while thinking about how I will EQ them and how hard it might be. so of course the ones I get are often easy to EQ to my taste and I don't apply much EQ. it's like how my DACs sound the same to me, I buy them based on specs suggesting they will. and if they don't I send them back. so of course I'm self confirming that all my DACs sound the same to me ^_^.

    I don't know about EQ APO directly with an EQ interface, I haven't used it much and it was a while ago. but I've read an update showing plenty of cool convolution stuff. so I imagine there are ways. worst case scenario, you could make your own EQ with some VST EQ that does whatever you want it to do, turn that into an impulse somehow(you might need someone who knows what he's talking about for that), and then use that in EQ APO's convolver. again I'm really a noob when it comes to those stuff, but I don't imagine a convolver cares about the type of impulse we feed it. someone who knows stuff can confirm or troll me or offer a less messed up solution?
    personally I got used to virtual cables and routing whatever I like anywhere I like. it can be more annoying and I would advise people to go for EQ APO if it does all they want. but as I keep switching between configurations and types of VSTs, it's just easier for me to always know where I am with a given VST host and loaded settings. I use DMG Equilibrium for EQ, expensive and really overkill for what I do. but one day I got frustrated when some free EQ crashed on me while I was done with about 20 bands done by ear with test tones. I got mad and went to buy a professional EQ. I got this one instead of proQ because Bob Katz had been talking about it a little and I remembered that. all BS reasons but here I am with my fabulous EQ. I'M NOT SHORT TEMPERED!!!!!!!! ^_^

    again as you clearly seem to understand how the final output level is relevant, I don't see the need to dissuade you from doing what works for you. I'm more talking about rule of thumb for those who don't think too much beyond moving a slider, and getting a new sound. as long as you can estimate your needs, like power of the amp having to compensate for the digital gain attenuation, or even better if you can confirm in practice that it's fine, then by all means, you do you! :wink:
  10. alex_aiwa_USA
    I have been using APO EQ to dial in a filter setting for an IEM I'm testing.

    In case anyone finds it handy, someone made a nice visual GUI for it, ProAPO - not sure if it's well known as there don't seem to be comments on it. The only one I could find that put a nice GUI and lets you do it parametric style.

    I'm 80% sure it's not a virus.


    Making an impulse with VSTs and then running it with a convolver should work fine in theory. Probably you would want to use a sweep (better go for 0-22khz in this case) and then run it through Voxengo's Deconvolver (because this is the only free one I know off the top of my head) to be sure to get a good quality result. The alternative is to feed it a Dirac impulse and just record the output... but some DAWs need coaxing to actually properly handle a single sample impulse, they will automatically declick, things like that.

    However, unless you're mightily concerned about the phase distortion in APO and you're also sure that the convolver has less, I would not do it that way. Much more effort and harder on your CPU, too. And then you have to repeat the process for any tweaks to the EQ later on.

    For acoustic space simulation (call it fancy crossfeed alternatively) an impulse is a great solution but I think it's a bit impractical for EQ.
    castleofargh likes this.
  11. bigshot
    On my Oppo PM-1s, my preferred EQ is less than 3dB in a fairly narrow band. They are very close to ideal. My speakers have a little more correction. I think my biggest correction is about 4.5 or 5 dB. But it's in the top octave, so it isn't all that important. I've been thinking about lessening it. I have a really big correction in the sub bass, but that is a kludge to make the crossover to the subwoofer better. I do a low end roll off with EQ at the bottom because I find that the crossover on the sub has a roll off too. It dovetails the hand off better.
  12. RRod
    I find my PM-3, which are pretty similar in response, way too heavy from 500-3000Hz.
  13. bigshot
    I found two 3dB bumps at 3kHz and 6kHz. The main difference between the PM-1 and the other Oppo cans is the consistency of quality control. I heard that the PM-1s are required to have a response curve with no more than +/-1dB.
  14. Joe Bloggs Contributor
    EQ APO's built in EQs are FIR based but minimum phase and "zero delay". You can also load 32-bit or 64-bit VST plugins depending on your system (usually 64-bit required), two linear phase EQs I know of are ReaPlugs ReaFIR and Voxengo CurveEQ (the latter being switchable to minimum phase as well)
  15. orderingrabbits
    I have up to 6dB boosts (with pre-amp obviously) but up to 10dB cuts - sometimes my ears pick up really high Q peak in test signals that I notch down quite heavily - it doesn't impact the percieved FR too much, but I am somewhat curious about what a high Q high dB (typically 10-15Q, 5-10dB reduction) notch in the treble would do to phase response and how audible that would be (I'm guessing it's a small difference if any).

    Thanks, I'll give some of those a try when I have the chance.
    Last edited: Nov 9, 2017

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