View Full Version : Audio restoration

04-27-09, 08:25 PM
We have all these live Hendrix boots, and about 60% of them fall below a 5 in terms of audio quality...I know that audio restoration can only go so far in the present, but how far can it really go? Can it bump a 5 up to a 6? 7?

What about the future? Is it even possible to take a 5 and turn it into a 9? Could we one day turn all these poor quality boots into somewhat decent recordings? Will some breakthrough occur?

What is the potential?? I ask because I am entirely ignorant on the subject, and like to imagine that one day I will be able to listen to these lesser-quality recordings clearly. I just sit and dream about it while listening sometimes...


So what do you think??

04-27-09, 09:01 PM
... and like to imagine that one day I will be able to listen to these lesser-quality recordings clearly. ...
So what do you think??I think the day you desire will happen in a time that will provide the enjoyment to your great-great-great-great grandchildren.

Your best bet now is to use any dsp available to your audio system and tweak to taste.

04-28-09, 12:19 AM
With the merges, with 3 poor sources, we are able to listen concerts in much better conditions. A little more bass here, a little more voice there... And the audio quality become acceptable.

purple jim
04-28-09, 12:42 AM
I would imagine that with the merges for example, things are as good as they can get. On some tapes for example the drums are simply not there. There is nothing to build on or extract. Could a new technology permit one to select a minute residual trace that could be separated, enhanced an cleaned up ? Sounds like science fiction today.

04-28-09, 06:12 AM
Has anyone heard of people using DBX technology to improve the bass on their merge "craft"?

Back in my vinyl days I used a DBX 110 subharmonic synthesiser that would sample the bass material present and recreate the lower bass frequencies that should have been present on the recording, but were likely filtered out for mastering.

The DBX 110 worked great however it had to be adjusted (of course) for nearly every track because of the variability of present/missing bass frequencies. For audio restoration it could be run once and digitally recorded, and alleviate the most common problem of missing bass on audience sources. I think DBX 110's are still commonly found on ebay.


04-28-09, 10:32 AM
It will only be possible after flying saucers land. Just ask the Axis!

04-28-09, 03:40 PM
Aah, I understand...I thought as much :( ...I guess I'll have only to dream

Good insight

Also, I suppose this pertains to the topic...Can anyone suggest a good pair of headphones? I am having a lot of trouble finding some that won't break! Thanks!! Not skullcandy, though..and not too expensive :)

04-28-09, 04:45 PM
but don't lost your fate, there is always a chance that a better source will come up.

I still believe that someday we will have the Harlem gig in a better source...

04-28-09, 05:16 PM
Aah, I understand...I thought as much :( ...I guess I'll have only to dream

Good insight

Also, I suppose this pertains to the topic...Can anyone suggest a good pair of headphones? I am having a lot of trouble finding some that won't break! Thanks!! Not skullcandy, though..and not too expensive :)

I use a pair of Sennheiser HD424 that I paid $130 for back in 1984. That's more than $300 present cost indexed to inflation. However they let alot of sound out around me and that can annoy others in the room.

A headset I use most often today is a Plantronics P590A stereo set that comes with the bluetooth wireless adapter analog transmitter. It is extremely comfortable, sounds excellent, and is nearly silent to others in the room. I would not recommend it as a non-destructible unit however. It is a delicate design that swivels and collapses to fold into a hard carry case. I treat mine with great care as it is very valuable to me. You can buy them at amazon.com, here is the link:



04-28-09, 06:55 PM
Sony MDR-V6 area good deal, and sound good. Comfortable, great sound.

Here's a link comparing Sony and Sennheiser headphones that run about $70 each.


04-28-09, 09:27 PM
Thanks for the tips, the earbuds I've been using since August are beginning to crackle and the wire is also deteriorating...I figure a good set of headphones is a good investment.

04-29-09, 04:57 PM
I think it is possible. What you essentially do is to add information.

You know basically how Jimi's guitar sounds during other concerts which were recorded professionally. Same with his voice, the drums of Mitch Mitchell, the bass guitar of Noel or Billy Cox etc......

And then some hyper advanced computer program could use this information to simulate how the audience recording could have sounded. But the end result would be fake in my opinion. Not real.

Roland Stone
04-29-09, 08:55 PM
Who cares if its real or memorex as long as it sounds better? If we could take a show like Phoenix and make it sound like Winterland, I wouldn't mind if it was some computer algorhythm's idea of what it might have sounded like, as long as it sounds GOOD!

I think we probably already have the computer horsepower to accomplish this. What we need is 10 caffeinated M.I.T. geeks working together on the algorhythms for 100 months. And then another 10 Hendrix freaks on THC in an adjoining building to fine tune the software. Maybe we can get Paul Allen to pay their salaries?

04-29-09, 09:19 PM
Doesn't this sound like an episode of "The Big Bang theory"? Someone call the writers!


04-30-09, 06:50 AM
Best thing you can do with old audience tapes (or any tape, for that matter) is transfer them with the best equipment possible. Really makes a difference. You can also tweak them afterwards, I suppose, but the original transfer method is the key. Also using the best (lowest gen) source helps, of course.

my favorite equipment:
Cassette: Nakamichi CR-7a with manual azimuth adjustment.
Reel: Revox (any of them).
VHS Video: JVC HR-DVS3U with firewire output.
Betamax: got an old Sony deck that was from a TV studio. Built like a tank.

use good cables, that makes a big difference too.

transfer audio using those high-end cables, to an outboard digital to analog converter box (i've got an Edirol FA-66), import to your computer software at 24 bit/96 kHz.

transfer video from the JVC deck via firewire direct to the computer (no outboard converter box needed) in DV mode. Edit in Final Cut Pro or something similar (like Avid for PC`s). Use a good program like Apple's Compressor to convert the DV video to MPEG-2.

I found that doing the best possible conversion is preferable to doing any kind of EQ or tweaking. I know some (well lots) of the tapes are a bit rough, but after you get accustomed to that kind of thing, you'll find that EQ is a very subjective thing. Everybody's idea of what "sounds good" is different. I've heard a lot of remasters from the torrent sites, and I find that most of the time, the original audio is better to my ears. There's a few exceptions of course, the only one I really can vouch for is the Jimi in Honolulu tape. The original sounds like it was recorded in the back of the hall, in the mens's room, with the microphone buried in the trash can under a pile of paper towels. The taper, a professional musician, reworked the tape in a professional studio. His re-master really did sound better than the original recording.


04-30-09, 07:12 AM
azimuth alignment is the key of it all when it comes to transferring old cassettes. you must tune in your playback heads to the tape you transfer. that makes a huge difference.

04-30-09, 11:27 AM
I'm in agreement on the so-called "EQ" yielding unfavorable results. Yes it sounds different but closer (equal) to what benchmark? I listen to tubes exclusively avoiding transistor power amp stages due to "listening fatigue" I encounter when subjected to transistor sound.

I never use the preamp EQ stages in any of my tube equipment which includes McIntosh, Scott, and Harman Kardon gear. I maintain a flat position on the tone controls and avoid equipment that sounds bad in those settings.

The only type of EQ I find any satisfaction with is adjusting the volume output of my Klipsch subwoofer which I have crossed over at 35HZ. Given this listening practice, I find that material stated as EQ'd by others before posting, usually sounds extremely harsh to my ears. But then that arises from being spoiled by over 3 decades of warm glass audio.

I've lived in places where subwoofers aren't compatible with neighbors and that's a very unfortunate situation. There are very few listening experiences that can't be improved by recreating accurate bass response and presence. In fact in my opinion most recordings have terribly compromised the bass element deliberately.

Hopefully someday digital technology will be effective in driving the knob twiddlers out of the studio, down the road, and off the bridge where they belong. Returning to dynamic range, accuracy and natural acoustics can do nearly as much for music as the most gifted musicians.


04-30-09, 12:03 PM

Kinda reminds me of the search for the
best turd polish - :D


Roland Stone
04-30-09, 07:57 PM

Kinda reminds me of the search for the
best turd polish - :D


Of course you know nothing works better for that than saliva?

purple jim
05-10-09, 07:31 AM
The 3 source merges of LA Forum 70 and KB Hallen 70 are remarkable achievments. A big round of applause for the kind soul(s) who put them together for our listening pleasure.

05-11-09, 03:54 AM
the merge works ,give the quality an upgrade,,

i cut lot of treble & some middle freq,

i did some washing of pre-war blues

i filtred the high freq too 6000 hz,
this took away most of the scratches,,