Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Does acoustic feedback change vinyl sound (Read 3009 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Does acoustic feedback change vinyl sound

I remember that in discussions about the vinyl sound, someone here said that vinyl could be listened louder than CDs in clubs, because they sounded better at high volume.
I then suggested that there would be a feedback into the turntable, because of the vibrations, that would only occur with vinyl, and make it sound different than CD at high volumes.

In order to test this hypothesis, I put one of my speakers in front of the turntable, and made two recordings : one with quite no sound, and the other at full power, with the turntable into the sound (thank god the neighbours were not at home).

MPC file with feedback (180 kB)
MPC file without feedback (180 kB)

You can play them looped.
The volume must have been around 100 db, but with much bass. Near the turntable, I could feel my clothes vibrate a little.

[span style='font-size:8pt;line-height:100%']
Setup :
Technics SL-3100, Stanton Trackmaster EL, on a wooden table. Arcam Diva A85 ampli, Dynaudio Gemini speakers, on stones, themselves on rubber. The floor is a carpet on I-don't-know-the-english-word-for-ceramic-pieces-to-cover-the-floor. Turntable 20cm from the speaker.
The feedback sample is 0.12 db quieter because I first recorded with the Ampli playback source set on the DAT deck, that was recording. Then, I remembered that the DAT introduces a delay in the ms range. I redid the recording with the ampli on the phono input. I later realized that the load at the output of the phono preamp would not be the same and the levels would be different (phono preamp to DAT (tape out 1) // analog equalizer (tape out 2, not used here) in the first case, versus DAT (tape out 1) // analog equalizer (tape out 2) // ampli (internal) for the second recording).

[/span]

Does acoustic feedback change vinyl sound

Reply #1 –
Quote
I-don't-know-the-english-word-for-ceramic-pieces-to-cover-the-floor.

Typically, "ceramic tile".

Does acoustic feedback change vinyl sound

Reply #2 –
I did not listen to your samples, but I can answer yes from personal experience.

I still have a Linn Sondek turntable at home with a Glantz cartridge and cartridge preamp, which I have not used in some time, but I have found in certain situations, it was possible to get feedback. One particular time, I was playing around with the counterweights on the tone arm to get the pressure and tracking just right, and I set it a little too light. At the same time, my daughter (~18 months old at the time) walked in and was fiddling on the volume knob on my amp without me realising. I then lowered the tone arm on to an LP, and it screamed like a banshee. She started crying, I got the fright of my life, but then we both just cracked up and laughed. I fiddled around with it some more, and I could get some lovely howling feedback. It would have made Jimi Hendrix smile... 

I have since discussed this with some vinyl nuts, and they say it can happen from time to time, depending on the type of turntable and cartridge, speaker placement, etc, etc.

The floating style tone arm, and certain sensitive stylus cartridges are more prone to this effect.

Den.

Does acoustic feedback change vinyl sound

Reply #3 –
Well, although I expected to hear a difference, I heard no obvious difference playing it looped in fb2k with crossfeed & headphones(albeit with a loud PC fan) and my eyes closed.

There's a big mechanical impedance mismatch between a stylus and the air (hence really old (1920's) record players used horns) so maybe that explains lack of obvious effect?

Perhaps the louder sounds better thing is more to do with the Fletcher Munson curves - bass is perceived to become more dominant as loudness increases.

Does acoustic feedback change vinyl sound

Reply #4 –
It would be the same with CD...

For the samples, I didn't tell anything yet, but I hear like you : no obvious difference. No audible feedback.
Feedback exists, I've never be able to record a vinyl playing a CD, because the CD could be heard between the tracks of the vinyl, but when the feedback is the vinyl itself, the effect it quite inaudible with my setup.

In fact the test is completely inconclusive, because as Den said, other setups can suffer from feedback while mine doesn't. In a club, it is also possible that the studio speakers are put on the same table as the turntables, or even that the turntables touch the speakers.

Does acoustic feedback change vinyl sound

Reply #5 –
Yeah, I wouldn't expect much effect with his setup.  The speakers seem to be pretty well isolated from everything else through the stones and rubber.  Put the speakers on the same table as the turntables and then some feedback might occur.
 

Does acoustic feedback change vinyl sound

Reply #6 –
Crankypants, the feedback should happen through acoustic waves hitting the turntable, not vibrations transmited across the floor.