Hey all.

i know this is a weird request, but i'm trying to get a natural feeling, but extremely bass heavy sound.

yes, that sounds like a contradiction at first, but what i mean by 'natural' in this context is in the sense of what you would hear from an adjacent room to a music source, or while having ear plugs in or blocking your ears.

just turning the bass up and the treble down doesn't work - it sounds muffled and tinny in the midrange, the eq curve doesn't seem to shape as naturally as it does when actual objects (walls, plugs, etc.) filter the sound.

anyone have some tips for achieving such a sound?

i'm looking at mainly my iriver H340 running rockbox. i'm using creative EP-630 headphones.
I'd prefer to be able to use the inbuilt EQ however i don't mind using some 3rd party EQ software to get a sound i'm happier with.


for those not familiar with the rockbox EQ - this is a text file with info about it i collated from the rockbox manual and my own additions:

http://members.iinet.net.au/~trevor.weeden/rockbox.txt


i'd also like to do the same for my PC, however my current solution (which involves using some wood to cover the tweeter and mid-range drivers on my speakers - it works a lot better than you'd think!) is more than adequate for now, i'm pretty happy with the sound.

I would guess that the sound you are after results from the way in which solid objects resonate at specific frequencies and thus pass those frequencies very selectively while attenuating others. Try a filter with several very narrow passbands.

If you can't get the effect with a graphic equalizer, it's going to be tough... You might get the best results by recording the sound with a microphone.

I would also guess what you are lacking is resonance. Resonance is what makes a guitar string oscillate at a particular note, and it also causes the effect you get when you talk into a tin can, or if you talk with your head in a cardboard box, etc.

You can get ringing/resonance with a high-Q bandpass filter, but it would probably take several filters and lots of experimentation. First-off, you'd have to "find" the frequencies to use. And, a "normal" bandpass filter is not what you want... A normal bandpass filter will block-out everything except the pass-frequency... You need to give a big-boost to the bandpass frequency without "killing" everything else (maybe "parallel" filters). And, normal bandpass filters are usually designed not to "ring", so depending on the software, the Q-factor may be limited.

P.S.
If I understand you correctly... That you are looking for an effect to "enhance" the sound, and an effect to use all of the time (as opposed to a special effect that you use for special situations) you might try some reverb. And, for your home set-up a surround-sound system... All Dolby Pro Logic II receivers/decoders have "soundfield" settings that can send delay/reverb to the rear speakers. In general, you can "get-away" with more reverb from a surround-sound system. With headphones, (and with stereo speakers) it doesn't sound as natural, and you may have to back-off the reverb a bit. (True-natural reverb comes from all directions.)

A lot of people like to set-up the surround sound (for stereo music) for a very subtle effect.. so that you can't really "hear" the sound coming from the rear speakers, but so that "something's missing" when you turn-off the rear speakers.

You could certainly achieve this effect with a convolver DSP such as Foobar's foo_dsp_convolver if you can obtain a suitable impulse response for the natural conditions you wish to replicate, e.g. recording a balloon bursting in an adjacent room with a microphone. You could then use the convolver in the DSP chain when you listen to music in Foobar2000 and you could pre-process your music when converting (Foobar/Convert.../Enable DSP) to a format you can play on the Rockboxed DAP.

What will probably help you are frequency response diagrams. Take your pick:

http://www.ohropax.de/3-1-products.html

[prodcut of your choice] --> Sound Attenuation / Product Info --> bingo!

thanks for the replies. i'm mainly looking at obtaining this effect with an EQ curve - even if it's not the best solution, or the most accurate, it is the easiest as i don't want to sacrifice too much sound quality in the process.

reverb and echo aren't of interest to me, although it is a natural part of the real-life sound filtering i mentioned, sorry to not be specific enough with my OP.

if someone could, i'd love it if you could have a go at finding a good setting on a rockbox style EQ for this type of sound. the EQ is too complex for me to work with properly, i feel lost not fully knowing how each parameter will affect the sound.

eg. with the high shelf filter set at -24dB attenuation, and then if i increase the q of the high shelf filter, some of the high mid / treble increases, where as i would have assumed it would decrease by affecting a larger frequency area or bandwidth. all of the EQ bands seem more effective when used with the smallest q number - 0.5.

i started to get a decent sort of sound when putting the high shelf down to around 4-6kHz, with q of 0.5 at full attenuation (-24dB)
the low shelf filter sounded pretty good when set at 20Hz with 0.5 q and at full 24dB increase - i know it didn't directly shape the sound i'm listening for but i feel it gave the bottom of the curve that high shape to compensate for bass roll-off. most bass boosts don't get low enough to boost the very low kicks of the bass drum but not to un-naturally boost those midrange bass sounds like high toms and low voices etc. it's normally sounds boomy - but this didn't sounded good. rockbox has a normal overall bass boost anyway that i could use as well if needed to affect larger range of bass frequencies.

however i'm then lost as to what frequencies and in which directions to set the other lower frequencies with the 3 more normal bands. this is where the sound is lacking, trying to get the mids to fill in the middle of the eq curve naturally. i'm guessing somewhere like 200 - 4000Hz? when i hear something i want to change, i don't know how to pinpoint which frequency range is too high or too low - i just use trial and error. and with this EQ there are far to many variables and it's taking ages and frustrating me.

if anyone has the rockbox EQ i'm talking about (or can tell enough from the txt file i hosted) to give it shot for me i'd be grateful.

would this be possible by using the rockbox EQ with the high shelf set to something really low like 3-4kHz, and then using one or two of the main peak filters to do as you say and selectively pass the frequencies needed for resonance?

i'm a bit of a novice at this detailed type of sound manipulation / characteristics.

I once demonstrated a 3rd order butterworth low pass, and the reaction to it was pretty much like your request

Such a filter is -120dB down at 17kHz, way beyond normal equalizer settings.....

you can try this software : it integrates same parametric EQ as Rockbox and same crossfeed but it is much easier to setup and use. When you have found parameters to suit your needs, you can copy those to Rockbox.