I wonder if there exist some spec or transfer function of a filter that would immitate the responce of an old gramophone or 78s. I am retrfitting an old gramophone with modern mp3 electronics but like it to sound more "authentic".
Filter to Immitate Gramophone
Started by ●August 27, 2007
Reply by ●August 27, 20072007-08-27
On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghuang@comcast.net> wrote:>I wonder if there exist some spec or transfer function of a filter >that would immitate the responce of an old gramophone or 78s. I am >retrfitting an old gramophone with modern mp3 electronics but like it >to sound more "authentic".Hi, Ha. That sounds like a neat project. I certainly don't know what is the correct answer, but I'll bet you'll have to pass the "high-fidelity" audio through some sort of bandpass filter that attenuates low frequencies as well as attenuating high frequencies. Just what the filter's low- and high-frequency cutoff values should be is the question. Then again, because nothin' is ever as simple as it first seems, maybe this is complicated problem. Perhaps you'll need to implement some truly oddball "equalizer." If you solve this problem, I hope you share your solution with us. Good Luck, [-Rick-]
Reply by ●August 27, 20072007-08-27
R.Lyons@_BOGUS_ieee.org (Rick Lyons) writes:> On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghuang@comcast.net> > wrote: > >>I wonder if there exist some spec or transfer function of a filter >>that would immitate the responce of an old gramophone or 78s. I am >>retrfitting an old gramophone with modern mp3 electronics but like it >>to sound more "authentic". > > Hi, > Ha. That sounds like a neat project. > > I certainly don't know what is the correct > answer, but I'll bet you'll have to pass the > "high-fidelity" audio through some sort of bandpass > filter that attenuates low frequencies as well > as attenuating high frequencies. Just what > the filter's low- and high-frequency cutoff > values should be is the question. > > Then again, because nothin' is ever as simple as > it first seems, maybe this is complicated problem. > Perhaps you'll need to implement some truly > oddball "equalizer." > > If you solve this problem, I hope you share your > solution with us.It's not just linear distortion that needs to be modeled, but also noise. No? -- % Randy Yates % "Remember the good old 1980's, when %% Fuquay-Varina, NC % things were so uncomplicated?" %%% 919-577-9882 % 'Ticket To The Moon' %%%% <yates@ieee.org> % *Time*, Electric Light Orchestra http://home.earthlink.net/~yatescr
Reply by ●August 27, 20072007-08-27
On Aug 27, 12:29 pm, R.Lyons@_BOGUS_ieee.org (Rick Lyons) wrote:> On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghu...@comcast.net> > wrote: > > >I wonder if there exist some spec or transfer function of a filter > >that would immitate the responce of an old gramophone or 78s. I am > >retrfitting an old gramophone with modern mp3 electronics but like it > >to sound more "authentic". > > Hi, > Ha. That sounds like a neat project. > > I certainly don't know what is the correct > answer, but I'll bet you'll have to pass the > "high-fidelity" audio through some sort of bandpass > filter that attenuates low frequencies as well > as attenuating high frequencies. Just what > the filter's low- and high-frequency cutoff > values should be is the question. > > Then again, because nothin' is ever as simple as > it first seems, maybe this is complicated problem. > Perhaps you'll need to implement some truly > oddball "equalizer."You might also consider adding some hiss and pops to emulate wear and dust in the record grooves, as well as some relative sample rate variation to emulate the wow, flutter and slow down of a mechanical drive. Not sure if there could be any reverb effects due to the non-amplifier horn feeding back to the platter. IMHO. YMMV. -- rhn A.T nicholson d.0.t C-o-M
Reply by ●August 27, 20072007-08-27
On Aug 27, 3:54 pm, "Ron N." <rhnlo...@yahoo.com> wrote:> On Aug 27, 12:29 pm, R.Lyons@_BOGUS_ieee.org (Rick Lyons) wrote: > > > > > > > On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghu...@comcast.net> > > wrote: > > > >I wonder if there exist some spec or transfer function of a filter > > >that would immitate the responce of an old gramophone or 78s. I am > > >retrfitting an old gramophone with modern mp3 electronics but like it > > >to sound more "authentic". > > > Hi, > > Ha. That sounds like a neat project. > > > I certainly don't know what is the correct > > answer, but I'll bet you'll have to pass the > > "high-fidelity" audio through some sort of bandpass > > filter that attenuates low frequencies as well > > as attenuating high frequencies. Just what > > the filter's low- and high-frequency cutoff > > values should be is the question. > > > Then again, because nothin' is ever as simple as > > it first seems, maybe this is complicated problem. > > Perhaps you'll need to implement some truly > > oddball "equalizer." > > You might also consider adding some hiss and pops > to emulate wear and dust in the record grooves, as > well as some relative sample rate variation to emulate > the wow, flutter and slow down of a mechanical drive. > Not sure if there could be any reverb effects due to > the non-amplifier horn feeding back to the platter. > > IMHO. YMMV. > -- > rhn A.T nicholson d.0.t C-o-M- Hide quoted text - > > - Show quoted text -ask the question over at rec.audio.pro Mark
Reply by ●August 27, 20072007-08-27
panabiker wrote:> I wonder if there exist some spec or transfer function of a filter > that would immitate the responce of an old gramophone or 78s. I am > retrfitting an old gramophone with modern mp3 electronics but like it > to sound more "authentic". >I can't really remember how does the real gramophone sound like. However several resonant peaks with Q ~ 10 at the frequency of ~500Hz and its harmonics will make a distinctive "metallic" sound. You can also add the low rumble, hiss and flicks to it. Vladimir Vassilevsky DSP and Mixed Signal Design Consultant http://www.abvolt.com
Reply by ●August 27, 20072007-08-27
Randy Yates wrote:> R.Lyons@_BOGUS_ieee.org (Rick Lyons) writes: > >> On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghuang@comcast.net> >> wrote: >> >>> I wonder if there exist some spec or transfer function of a filter >>> that would immitate the responce of an old gramophone or 78s. I am >>> retrfitting an old gramophone with modern mp3 electronics but like it >>> to sound more "authentic". >> Hi, >> Ha. That sounds like a neat project. >> >> I certainly don't know what is the correct >> answer, but I'll bet you'll have to pass the >> "high-fidelity" audio through some sort of bandpass >> filter that attenuates low frequencies as well >> as attenuating high frequencies. Just what >> the filter's low- and high-frequency cutoff >> values should be is the question. >> >> Then again, because nothin' is ever as simple as >> it first seems, maybe this is complicated problem. >> Perhaps you'll need to implement some truly >> oddball "equalizer." >> >> If you solve this problem, I hope you share your >> solution with us. > > It's not just linear distortion that needs to be modeled, > but also noise. No?And nonlinear effects, to, I would imagine. Altogether it would be an interesting challenge, particularly if you wanted to mimic _different_ gramophones and recording equipment. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●August 27, 20072007-08-27
Tim Wescott <tim@seemywebsite.com> writes:> Randy Yates wrote: >> R.Lyons@_BOGUS_ieee.org (Rick Lyons) writes: >> >>> On Mon, 27 Aug 2007 11:28:58 -0700, panabiker <ghuang@comcast.net> >>> wrote: >>> >>>> I wonder if there exist some spec or transfer function of a filter >>>> that would immitate the responce of an old gramophone or 78s. I am >>>> retrfitting an old gramophone with modern mp3 electronics but like it >>>> to sound more "authentic". >>> Hi, >>> Ha. That sounds like a neat project. >>> >>> I certainly don't know what is the correct answer, but I'll bet >>> you'll have to pass the "high-fidelity" audio through some sort of >>> bandpass filter that attenuates low frequencies as well as >>> attenuating high frequencies. Just what the filter's low- and >>> high-frequency cutoff values should be is the question. >>> >>> Then again, because nothin' is ever as simple as it first seems, >>> maybe this is complicated problem. Perhaps you'll need to >>> implement some truly oddball "equalizer." >>> >>> If you solve this problem, I hope you share your solution with us. >> It's not just linear distortion that needs to be modeled, >> but also noise. No? > > And nonlinear effects, to, I would imagine. > > Altogether it would be an interesting challenge, particularly if you > wanted to mimic _different_ gramophones and recording equipment.By the way, here are a couple of recordings kindly made available by Serge Auckland. http://audiopages.googlepages.com/otherstuff You'll have to scroll down a bit to get to two mp3 links of his gramophone recordings. -- % Randy Yates % "...the answer lies within your soul %% Fuquay-Varina, NC % 'cause no one knows which side %%% 919-577-9882 % the coin will fall." %%%% <yates@ieee.org> % 'Big Wheels', *Out of the Blue*, ELO http://home.earthlink.net/~yatescr
Reply by ●August 28, 20072007-08-28
panabiker wrote:> I wonder if there exist some spec or transfer function of a filter > that would immitate the responce of an old gramophone or 78s. I am > retrfitting an old gramophone with modern mp3 electronics but like it > to sound more "authentic".Cut the lows below about 150Hz and the highs above 2KHz. Iss a few notches and a few resonant peaks. Jerry -- Engineering is the art of making what you want from things you can get. ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Reply by ●August 28, 20072007-08-28
On Aug 28, 6:28 am, panabiker <ghu...@comcast.net> wrote:> I wonder if there exist some spec or transfer function of a filter > that would immitate the responce of an old gramophone or 78s. I am > retrfitting an old gramophone with modern mp3 electronics but like it > to sound more "authentic".Well it's all been said but a good high pass filter makes music tinny. Add some white noise as well and it's a start. There is a distinct sound of a 78 though - the needle in the groove sound and of course the sound at the end as it spins on the end of the groove.
