it's time to do some audiophile myth busting again and this time it's the claim that when you're
playing records it's best to leave the turntable's dust cover open or preferably remove it entirely
and it's not just random people on internet blogs and message boards telling you that
it's also many of the companies who make the turntables telling you that
Fluance a very popular manufacturer of turntables sold today says on their web
site while playing an album on your turntable you'll get the best results with the dust cover
removed as this is not often possible you should always keep the dust cover open when
playing your records closing the dust cover during playback can cause skipping from the
impact of the cover as well as feedback and distortion from sound within the cover
and Pro-Ject another popular manufacturer of turntables says removing the dust cover
generally improves playback quality as the large lid surface captures
airborne resonances and transmits them to the chassis or plinth this
applies equally if the cover is not removed completely but is left open during replay
and Audio-Technica whose turntables are some of the best-selling models today says
in their owner's manuals the dust cover should remain open or off while records are playing
however Victrola which sells very inexpensive record players gives the opposite advice they
say keep that dust cover down when you're not using your record player and if the
player allows even when you are it's an invaluable line of defense against debris
so what are the arguments for keeping the dust cover closed when playing a
record well obviously as its name suggests it protects the record and the turntable from dust
and if you look here in the RCA Radiotron Designer's Handbook under the section Record
and Stylus Wear it says in bold print "dust is the most important cause of record and stylus
wear with final records in the home and care should be taken to reduce it to a minimum"
and also leaving the dust cover closed helps protect the record and your turntable against
accidental damage from children or pets or any other kind of accident [Music]
closing the lid while playing a record can also help to muffle the needle talk coming
from the stylus which can be quite noticeable especially on turntables with a ceramic cartridge
now the arguments against leaving the dust cover closed when playing a record are that
the cover acts as an acoustic chamber and the stylus works by picking up vibrations
so any vibrations that the stylus generates within this cover is going to be reflected
back at it which can affect the sound quality supposedly nobody's ever been
able to prove that but that's what they claim and also external vibrations such as
from your speakers can also resonate on this cover and affect the sound quality that way
so they claim by leaving it open when you're playing a record you don't get that acoustic
chamber effect so any vibrations just pass through the air and don't get reflected back at the stylus
however even leaving this up like this it's still attached to the turntable so any vibrations this
picks up are still going to be transmitted through the base of the turntable into the
tonearm and the stylus so that's why they say to remove it entirely when you're playing a record
and the proof to give is that when the turntable is playing a record and the dust cover is closed
if you tap on it you can hear it being picked up by the stylus as a thumping noise to give an
example that I have a record playing here this is just for demonstration purposes I needed to
find something with speech on it so during the pauses in the speech you can hear the
noise more easily than if it was playing music and also this should not hit a copyright match
so here's the setup a Technics SL-QD33 quartz lock direct drive turntable with
a Grado green cartridge connected to this mixer acting as a phono pre-amp here's the
camcorder recording the main action I have its video output connected to the video input
of this other camcorder and the audio input of that other camcorder is connected to the
output of the mixer so this is recording both the image of the turntable playing
and the audio coming out of the pre-amp it's a direct connection
first I'll have the record playing and I'll tap on the lid and on the base of
the turntable then I'll open the dust cover and tap on the lid in the base of the turntable then
I'll remove it entirely and I'll also tap on the turntable and you can hear the difference
the basic issues of the presidential campaign of 196... the incumbent Lyndon Baines Johnson
"we want a government that's fiscally solvent... fiscally solvent and that's
compassionate that meets the needs of the future of physical and mental and spiritual strength...
Johnson's kind that we're working toward" the challenger Barry Morris Goldwater "I've
always stood for government that is limited and balanced and... authority in Washington
I've always stood for individual regimentation I believe we must... endlessly down toward a time"
well I don't know about you but to me it sounded like the amount of noise picked up by tapping on
the turntable and the dust cover was actually the worst with it open because when it's closed
it has little rubber feet that press against the base of the turntable which absorbs the
vibrations picked up by the cover but leaving it open it's free to vibrate and you can hear it
reverberating when I tapped on it
so to me the proof of this test is that it's best to either leave it closed when
playing a record or remove it entirely not leave it open but still attached
to the turntable when playing a record because that's the worst
how about this claim that leaving the dust cover closed when playing a record is also bad because
it also picks up vibrations external to the turntable such as from your speakers those
will also cause this cover to resonate which will also be picked up by the stylus so if that
theory is correct it shouldn't matter whether the speakers are playing what the turntable is
playing or something completely different either way the vibrations are going to be
picked up by the stylus and possibly amplified by leaving the cover closed or even open possibly
so to test that I'll have the turntable playing that same test record of that presidential
speeches and I'll have this stereo system playing a CD with some music on it through these speakers
I'll have the same hookup and if you hear anything that sounds like music when it's playing the
record you'll know it's being picked up by the speakers through the stylus of the turntable
from foreign policy we go to another major issue of 1964 defense spending
an issue that has no doubt been an issue since 1775 when an obscure naval officer
by the name of John Paul Jones begged the Continental Congress to buy him a
ship then it was only a matter of thousands of dollars by 1800
from foreign policy we go to another major issue of 1964 defense spending
an issue that has no doubt been an issue since 1775 when an obscure naval
officer by the name of John Paul Jones begged the Continental Congress to buy
him a ship then it was only a matter of thousands of dollars by 1800 defense was
from foreign policy we go to another major issue of 1964 defense spending an issue that has no
doubt been an issue since 1775 when an obscure naval officer by the name of John Paul Jones
begged the Continental Congress to buy him a ship then it was only a matter of thousands of dollars
well in that case I definitely could hear the vibrations from the CD player and the
speakers being picked up by the turntable but that was with the speaker is directly on the
same surface as the turntable which all the experts say you shouldn't do
so next I'm going to put some foam pads underneath the speakers to help isolate
them from the turntable surface and see if that makes a difference
from foreign policy we go to another major issue of 1964 defense spending an issue that has no
doubt been an issue since 1775 when an obscure naval officer by the name of John Paul Jones
begged the Continental Congress to buy him a ship then it was only a matter of thousands of dollars
from foreign policy we go to another major issue of 1964 defense spending an issue that has no
doubt been an issue since 1775 when an obscure naval officer by the name of John Paul Jones
begged the Continental Congress to buy him a ship then it was only a matter of thousands of dollars
from foreign policy we go to another major issue of 1964 defense spending an issue that has no
doubt been an issue since 1775 when an obscure naval officer by the name of John Paul Jones
begged the Continental Congress to buy him a ship then it was only a matter of thousands of dollars
this time with the foam pads underneath the speakers I could still hear some of
the vibrations from the music playing through the speaker is being picked up by the turntable
stylus although it may have been reduced slightly but clearly did not eliminate it entirely so the
main issue is not the vibration of the surface it's just the vibration of the speakers through
the air and either way with or without these foam pads it seemed to be the worst with the dust cover
either open or removed entirely and seemed to be the least amount of feedback being picked up with
the dust cover closed the exact opposite of what all those experts and turntable manufacturers say
and if you combine that with my results of tapping on the turntable and the dust
cover it was clearly the worst of the dust cover open and attached to the turntable
the best results I got were either with the lid closed or removed entirely and if
you're wondering what is the music I was playing from the CD here's a sample of it
[Music]
now let's remove the speakers from the equation and focus on Fluance's claim
that even just the sound generated by the needle in the groove is enough to cause
feedback and distortion if you leave the dust cover closed while playing a record
for this test I'm going to use this 1986 stereo system by Quasar which was another brand in the
Technics and Panasonic family it has a ceramic cartridge which as I mentioned generates more
needle talk than a magnetic cartridge plus I'll be playing a 45 which is louder than most LPS so
this will be the worst case scenario of the sound generated by the needle being reflected by the
cover back at itself and possibly causing that feedback and distortion like Fluance mentioned
so I'll give you a sample of that record playing alternating between leaving the dust
cover closed opening it and removing it entirely and you can tell me if you hear any difference
[Music]
yeah I can't hear any difference either so the evidence would seem to suggest that despite what
the manufacturers of many turntables say if you want to leave the dust cover closed when
playing a record go right ahead any potential impact on the sound quality is going to be so
minor that you probably won't notice it and it's going to be far outweighed by
the benefits of protecting your turntable your stylus and your record from dust and accidents
but if you are obsessed with getting the maximum possible sound quality instead of
leaving your dust cover open it's far better to remove it entirely when you're playing a
record otherwise leaving it open like this seems to increase the amount of vibrations
your turntable picks up through the stylus the opposite of the effect you're trying to achieve