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Tone Controls: A topic about tone controls

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Topic: Tone Controls: A topic about tone controls
Posted By: Graham Slee
Subject: Tone Controls: A topic about tone controls
Date Posted: 09 Sep 2010 at 10:55pm
Tone Controls: A topic about tone controls

Yes, tone controls! Bass and treble tone controls.

That's bound to stir up controversy but never mind...

Some people like tone controls - some people hate tone controls.

I will begin this topic about tone controls with my experiences of tone controls - that's bass and treble tone controls (but I may make mention of a midrange tone control).

My findings could be summed up as "you only need tone controls if the equipment you're using is boring to listen to" - but is that really the case?

I have heard it said that tone controls are essential for room equalization and after setting up a number of public address systems I agree.

Now, the public address systems I refer to are the equivalent of high fidelity systems but for hearing by large audiences, and not the sort for factory/shop announcements or the bingo caller, although I have done some in my time.

After installing a new system in a lecture theatre (see pic)...



...using the JBL passive Eon loudspeakers as the main stereo pair, even equipped with 18" bass drivers, and powered by a quality 400 Watt amp (40V/uS slew rate and highly stable), the sound balance was quite lightweight in the bass region. The only solution was to turn up the bass on the Soundcraft mixer until it sounded right. Yes, it would have been better to install some large bass bins but the installation didn't allow - see the chair-lift on the left of the stage? Even by installing bass bins it means there would have still been EQ in the system by placing the emphasis on bass amplification to drive them. So, to balance the room acoustics required bass EQ.



Around the age of 17 and at the beginning of my journey into audio (and electronics in general), I didn't have much of a clue about hi-fi. I bought an Amstrad IC2000 Mk4 amp. In those days any amp sold by Comet was called hi-fi. The Amstrad had bass, mid and treble controls and with them set flat it was a very boring amp indeed. Put a "smile" on the tone control "faders" and it sounded half decent but emphasized record clicks and pops to such an extreme that the off-switch became the most important control it had.

Deciding to take it (and some Marsden-Hall speakers) to my local where I was meddling with trying to make a decrepit twin deck system work, I found what happens when the tone controls are up full as well as the volume...

The speaker voice coils pop out!

I had learned about "clipping".

I suppose it was inevitable that I would later join in with the "all tone controls are bad" brigade.

But after a number of PA installs/procurements, and the one mentioned earlier, I found myself in two minds about tone controls. Using headphones a lot I would definitely not use tone controls, but after auditioning speakers in different locations, I know they can sound quite considerably different, and believe that tone controls would help. The proviso has to be that the tone controls are used sensibly and never with full boost unless the room is completely unhelpful.

To be continued...



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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps



Replies:
Posted By: jonclancy
Date Posted: 10 Sep 2010 at 7:25pm
Interesting topic, Chaps.

Let me just throw this in the ring:  "Tone Controls are a very crude form of EQ - only just above changing speaker position etc."

I'm not sure if I actually believe that myself.  I can see how a tone control might help tailor sound to the location, or indeed to the listener and individual preference.  This preference  might also be tailoring to the differences we must all have in our generic, but varying, hearing response and perceptions.

Are DSP and room correction the same thing on a more advanced scale?

Discuss! Wink



PS I don't use tone controls, room correction or room acoustic treatment.  In fact, we have an acoustic piano in the same room that is probably singing along to everything played!  Would tone controls make some love the AKG K701 if they already find it bass shy?


Posted By: Fatmangolf
Date Posted: 10 Sep 2010 at 11:12pm
Good points and I agree with you about the differences between speaker repositioning and EQ.
 
In general do we want our personally preferred timbre or an idealised flat response in a real room? Most acoustic problems I've heard in venues and rooms are time related (i.e. the room resonates or rings and sustains certain frequencies and/or sucks out others which die off quickly) which are only covered up by adjusting the amp/speaker output with EQ. It depends how you feel about changing your room decor and about using EQ.
 
In guitar amps tone controls are crucial to sound shaping (if you're into valve amps think of a cathode follower driving a passive tone stack and gain make up), in other words the tone is being shaped with some distortion even at low gain. But no amount of EQ can make a small open backed speaker sound like a closed back 4x12" at high volume. Which is akin to Graham's point about trying to fill a large venue with bass when the speakers or amplifier lack the headroom. Luckily real life is about compromise and a little bass boost helps to make small speakers sound bigger, too much and it's obvious there's a problem. More so when the system is running at high volume with amps are clipping and speakers flapping.
 
Anyway back to hi-fi land. I would like to hear exactly what's on the record and have as little as possible in the signal path. That's easier with headphones and no EQ is needed. Choose carefully when you buy your headphones as you've hard wired your tone controls and more. Discuss.
 
Meanwhile in my living room with the speakers and sofa, I have bookshelves, racks of LP's and CD's, musical instruments like guitars and a TV.  And a cat which definitely can't be acoustically treated with tone controls. And some surround speakers and a subwoofer for watching DVD's, which could be used to add low bass. So I should expand Jon's room correction with bass management Wacko as an option for the topic! [Lets agree to not discuss surround sound processing of stereo, please!]
 
"Are DSP and room correction the same thing on a more advanced scale?"
Probably not. It depends if you're fixing the frequency response with some EQ or phase/delay which is most room correction usually done with DSP (digital signal processing), or adding an ambience or reverb programme to simulate being in a large concert venue which is also done with DSP.
 
My EQ comment is that a slight cut can reduce irritating peaks or tame HF shrillness, it can't fix the source. And boosting the bass or treble brings the sound of that circuit in.
 
I guess it's how far you deviate from the "straight wire with gain."
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Fatmangolf
Date Posted: 10 Sep 2010 at 11:18pm
I should add that I am not advocating the use of guitar amp tone stacks in hi-fi. The classic Baxendall bass and treble is good, but I have learned from Graham Slee's Genera design how critical the slew rate and op amp loading are in an active filter or EQ. So good EQ or no EQ!


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: mrarroyo
Date Posted: 11 Sep 2010 at 12:51am
The closest I have come to using tone control was back in the 80's where I used an equalizer. First a pink or white noise was generated and a mic was placed in my listening chair and the room equalized. It was a pain to do and I do not even remember the process, since I leave the controls at zero.

My only exception is on cars where I lower the treble a notch since I find the higher frequencies overdone in most car situations.

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Miguel


Posted By: tg [RIP]
Date Posted: 11 Sep 2010 at 9:36am
As someone of my acquaintance was wont to say, "there are more points to this than on a pineapple."
I may be incorrect, but I would suspect that tone controls were initially fitted as a sales gimmick and to cover the limitations of less than "hi fidelity" amplifiers and speakers.
Philosophically, any intentional, post production, source signal modification, could be seen to be contrary to the notion of "hi fidelity" reproduction.
Practically, there can be many valid reasons for such modification, particularly in the case of large venue sound reproduction where nowadays I believe it common to use sophisticated equipment that introduces time delay to closer speakers to synchronise them with more distant placements.
In a domestic situation, I would consider speaker placement to be of the first importance and any subsequent measures to be room treatments and finally EQ in that order, in the case of integrating a sub woofer the EQ might be considered before room treatment though even there treatment is preferable and subsequent to optimal positioning.
Many speaker manufacturers have and some still do, offer adjustment of individual drivers on the speaker itself.
The purpose of all these seems to be to achieve the most desirable balance at a particular "sweet spot" in the listening room.
I suppose that could also be considered to be "being faithful to the source" by presenting the best possible facsimile at the chosen listening position.
I know of systems using multiple amplifiers to drive different speakers and sophisticated DSP/EQ systems to produce reportedly stunning results at very high volumes in large rooms.
This is not my situation, I can not listen at very high volume very often out of consideration for my neighbours, living in a smallish apartment with neighbours either side and below.
I love my speakers for their portrayal of the recording venue and their soundstaging, something I cannot get from headphones, but being highly efficient BLH with 8" drivers they are never going to load the room to the degree other types will. I also use them in an almost nearfield configuration which obviates many room related issues, the drivers are at eye level when seated app 7' from them with some distance from my seating position to the not particularly reflective blinds behind.
The unkind might call such speakers "bass & treble filters".
Still, tone controls are not something I would consider introducing to my system, having regard to Graham's previous musings on the difficulty of implementing them without penalty and my own experience of improving the sound of my system by removing my preamp entirely.
That said, I am quite happy to try different I/Cs to adjust the sound and that might be considered a form of "tone control" although I see it as finding the best matching connector to provide the cleanest signal to the next stage.
I do not see that as being markedly different to replacing the fairly basic carbon track pot in my amplifier with a stepped attenuator using quality resistors which gave a marked lift in resolution and detail (and in fact showed my preamp up as a sonic bottleneck).
It could probably be argued that tube rolling, opamp swapping and capacitor changing are all forms of tone control.
Forgive me if I seem a little scattered here, I've been tinkering with a DAC I gave up on some time ago and the latest mods have been burning in for a week now and starting to sound like it might give my vinyl front end a run for the money, will have to put on some records later for a reality check, for now though it is sounding rather good and it keeps taking my attention from what I am waffling about.
Enjoy the music - I am ! Thumbs%20Up



Posted By: jonclancy
Date Posted: 11 Sep 2010 at 10:51am
Originally posted by Fatmangolf Fatmangolf wrote:

In general do we want our personally preferred timbre or an idealised flat response in a real room?


Personally preferred timbre, of course! Big%20smile  It's what I enjoy listening to.  And that will be shaped by my hearing response, taste, mood and a million other things...

Originally posted by Fatmangolf Fatmangolf wrote:

Choose carefully when you buy your headphones as you've hard wired your tone controls and more. Discuss.


I refer you to the above.  But headphone choice can be a pretty blunt instrument and although it gets you in the right area, tastewise, the sound might need a little more tweaking...
 
Originally posted by Fatmangolf Fatmangolf wrote:

"Are DSP and room correction the same thing on a more advanced scale?"
Probably not. It depends if you're fixing the frequency response with some EQ or phase/delay which is most room correction usually done with DSP (digital signal processing), or adding an ambience or reverb programme to simulate being in a large concert venue which is also done with DSP.

Agreed.  And nicely put.

Cheers

jon



Posted By: Fatmangolf
Date Posted: 11 Sep 2010 at 8:27pm
I agree with the other Jon, how many of us are really running a truly flat system?
 
Occasional use of EQ can make music more listenable. Just think of a muddled mix, or a dull sound lacking HF detail, or boomy bass than distracts from the rest of the instruments. Sometimes EQ may be quite helpful (I am a little nervous about writing this on a hi-fi forum and thinking about Graham's post of the Wicker Man photo as below).
But I shall go on. Slight HF cut with EQ is a quick fix for the "CD sound-a-like" trebly records of the '80's, although it won't make the midrange sound natural. It is a way to crudely adjust for non-RIAA pre-emphasis if you haven't got a Revelation. It can warm up a thin record lacking bass or brighten a dull mix.
 
Generally I can see 2 options:
  1. Well designed shelving EQ with good parts, including an off switch on the EQ
  2. Avoiding badly mixed and mastered records
Option 2 may limit your access to popular music and actually a fair bit of 60's and 70's Rock. Option 1 will allow you to listen to a couple of tracks, more if you can accept the warts and all. That is the subjective case for occasional use of EQ to fix sources.
 
Listening to real speakers in in real rooms means making some compromises. If the room were anechoic (no ambience or reverb from walls, ceiling, floor, or furniture) we would only hear the direct sound of the speakers, the ultimate version of being in the "nearfield." However, most of what we hear is a mix of direct sound from speakers, the early reflections from surfaces close to them, and longer delayed reflections that give the room reverb including its nodes and ringing. The sound we hear is not pure energy from the driver and enclosure, there is a complex system of room acoustics to consider. And your ears. Maybe making all that "flat" or simply personally acceptable justifies some EQ or room correction with physical treatment with soft furnishings/absorber panels or bass traps, or a sort of fix by DSP.
 
So headphones are a great fix because they eliminate the room. But they also eliminate the crosstalk between the ears, the natural delays and subtle filtering effects of sound going round the head, the outer ears, etc.
 
So how close can we really get to a straight wire with gain?
 
Jon (hearing the rustle of straw or wicker coming towards him)
 
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 12 Sep 2010 at 1:35pm
Originally posted by Fatmangolf Fatmangolf wrote:

But I shall go on. Slight HF cut with EQ is a quick fix for the "CD sound-a-like" trebly records of the '80's, although it won't make the midrange sound natural.

Yeah, shelved up to suit el-cheapo crystal and ceramic cartridges as fitted to "stacking lo-fi".

The crystal/ceramic playback slope turns over at 500Hz dropping 12dB to just above 2kHz where it shelves (continues on flat).

I'd guess they took a mean, turning over somewhere between 500Hz and 1kHz and shelving at +6dB.

I must admit to starting to develop bass and treble tone controls already. Not too much boost and cut (around ±10dB) and taking a look at the curve getting on for 3/4 treble cut, it's not far out from the above.

I think the audio pagans would have to build a very large wicker man to house us all...Wink


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: Graham Slee
Date Posted: 12 Sep 2010 at 2:06pm
Originally posted by tg tg wrote:

...I would suspect that tone controls were initially fitted as a sales gimmick and to cover the limitations of less than "hi fidelity" amplifiers and speakers.


Not far off base: tone controls were a necessity to play records (which is all we had back then*) before RIAA "standardisation". The first tone controls by Michael Volkoff in 1939, then E. J. James in Wireless World in 1949 and then P. J. Baxendall in Wireless World in 1952 - going on information found so far.

* OK, there was tape but with few users compared to records.


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: Graham Slee
Date Posted: 12 Sep 2010 at 4:10pm
Here's the boost/cut plot of what I'm currently working on...



The blue "centre line" is with the controls parked at their mid points and the grey "centre line" is in cancel. In my opinion the parked controls give a better cancel but that all depends on exact line up in construction.

The high frequency roll-offs of each curve show perfect stability at 20dB/decade.


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: jonclancy
Date Posted: 14 Sep 2010 at 2:08pm
Originally posted by Fatmangolf Fatmangolf wrote:

I agree with the other Jon, how many of us are really running a truly flat system?

SNIP

So how close can we really get to a straight wire with gain?
 


Not that many, I suspect.  But how close do we want to go (really, really close, because we like the idea of that) and opposed to how close do we NEED to go to a wire with gain.

There is, as I mentioned before, no accounting for differing tastes (or ears!) in a piece of gear with no correction available.  Is that why we end up tweaking so much......

Jon




Posted By: tg [RIP]
Date Posted: 14 Sep 2010 at 4:24pm

Quote But how close do we want to go (really, really close, because we like the idea of that) and opposed to how close do we NEED to go to a wire with gain.................Is that why we end up tweaking so much......

I think you are close to the heart of the matter here Jon, but I think it goes much further than mere tone controls or equalisation.

There are certainly situations and source materials which mandate their use in some form or other.

I think what we all are looking for is to recreate the musical event in such a manner as to allow our full participation therein - to feel the music if you will, to have the emotions conveyed to us.

What is needed for this to happen is for the audio illusion to have no "non-seqiturs" that impinge upon our consciousness and suspend our belief, an absence of ear jarring inconsistencies rather than absolute adherence to the truth of the source.

What this audio illusion will sound like will presumably vary from person to person - when my system "does it right" -  I could not care less about accuracy, flat response or any of the other "hi-fi" criteria - I just want to play more music.

When it is not doing that, then I tweak and swap things and wonder about upgrades, get fidgety, swap discs and try to recover "the magic", when it does I know.

Some tweak because it is a hobby within a hobby, some for the sake of finding out if it can be made better and some looking for that "je ne sais quoi" that moves the whole into another dimension where the particulars of the audio illusion are subsidiary to immersion in the musical event.

If correction/EQ is necessary to get you to the end of the diving board, use them.



Posted By: Fatmangolf
Date Posted: 14 Sep 2010 at 6:47pm
Yes tg you are right that there are different reasons for trying new things out. I note the difference between tinkering and tweaking, these are only words but I would like to explore your point.
 
There's tinkering by which I mean experimentation for its own sake, trying an idea or testing a concept. Diverting and sometimes fruitful, even serendipitous.
 
Tweaking is about getting a bit closer to a personal ideal by refining something you like. I think we all want the sound to be right to our ears, and to be clearer and more natural. tg, I like your use of the word "immersion" because I am always looking for instruments to sound natural and to feel as if I am in the room where the sounds were/are being made. Yes it is the audio illusion of a recording sounding almost real.
 
Some tweaks to the sound bring a desired improvement but unpalatable side effects. I would put poor EQ in this category. Lets not touch graphic equalisers but stick to bass and treble. I don't want an extra bit of HF on a dull sounding if the treble control makes the HF harsh or less coherent with the rest of the music. Or wanting to add a little more bass to add some body but getting loose "one note bass" instead.
 
A great EQ would offer the subtle equalisation when needed without bringing audible artifacts. A totally transparent EQ would be hard but this is the place to come judging by my GSP Genera preamp. I am interested in a very well designed and executed bass and treble control. To have that EQ with some input switching and level matching in a simple well built preamp would be brilliant. In a very nice custom design extruded case from a world class hi-fi company in South Yorkshire. Please Santa.
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 14 Sep 2010 at 10:18pm
Working on it, but half our works is a big hole in the ground right now and could take until late October for me to be able to move back in.

(don't worry, the big hole in the ground was planned...)Wink


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: tg [RIP]
Date Posted: 15 Sep 2010 at 2:55am

@ fmg - given the distinction you draw, I would see tinkering as both a perfectly valid occupation in and of itself but also as the research stage of tweaking from which the appropriate tweak may be drawn and applied as appropriate.

My feeling is that many of the cues that allow us to experience the content of the music rather than just the sound of the music, are very nearly subliminal and their reproduction very dependent on the phase coherence on which our esteemed host places such importance.

As an aside, I have recently come across some interesting reading on particular tweaks and tweaking in general from Thorsten Loesch, whose opinions are always worth consideration (IMO), @ http://www.enjoythemusic.com/magazine/equipment/0602/freakazoid.htm  

@ Graham - excuses, excuses, get on wi' it man.  Wink




Posted By: Fatmangolf
Date Posted: 15 Sep 2010 at 8:20pm

Agreed! We learn in playing and sometimes "I wonder if that would work here" can open up a new line of development.

That's a very good article and in sync with my thinking. Thanks tg.
 
Jon


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: jonclancy
Date Posted: 15 Sep 2010 at 8:29pm
I think Thor has been at the Lac!!! Wink

Only joking, T, if you read this!


Posted By: Fatmangolf
Date Posted: 15 Sep 2010 at 8:55pm

I would stop short of many of the tweaks in the article but the spirit of experimentation comes through clearly. Another thread topic would be tweaks that didn't last very long, it's down to the Lac I fear!



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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: tg [RIP]
Date Posted: 16 Sep 2010 at 12:52am

fmg - you have got the point of my referring that article - the general spirit of open minded experiment and the overall underlying philosophy.  All too commonly people seem to read such articles, find the one thing with which they disagree and proceed to "throw the baby out with the bath water" and dismiss everything they have read.  There are usually more colours than black in a packet of jelly beans and you don't have to eat the black ones if you don't like them.  

I/we digress - perhaps as you say, another topic.



Posted By: Fatmangolf
Date Posted: 16 Sep 2010 at 6:24am

Yes indeed tg!

I have now looked at the response curves on this thread several times and am amazed at the extended range and smooth slopes, especially the smooth drop off Graham has achieved. This could well be the transparent hi-fi EQ I mentioned above, an EQ that can boost or cut a few dB without bringing some sort of distortion.
 
From the GSP gear I have and the information from fellow owners, I know the design principles are right and will be expertly executed with layout and selected components. This EQ module will be very good indeed and presumably is at the centre of the forthcoming Aria preamp. That is an audiophile treat to look forward to.
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 16 Sep 2010 at 8:20am
I suppose if Thor placed sufficient felt pads (and I mean thousands) all over his room in groups making different heights he would eventually end up with an anechoic chamber, so I must conclude that such tweaks do work... in very liberal quantities Wacko

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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: tg [RIP]
Date Posted: 16 Sep 2010 at 9:47am

Aren't you supposed to be building some sort of bomb shelter for your new hi-fi rack or designing an equivalent performance alternative to the lightspeed attenuator for the new preamp or something ?

The rest of us can do the silly tweaking and chattering stuff to keep ourselves amused while we wait. Wink



Posted By: Fatmangolf
Date Posted: 16 Sep 2010 at 11:07am
I know you are only joking tg so I shall risk being cheeky to you as a moderator by saying our generous host deserves some downtime!
 
My experience with acoustic treatments suggests tens of thousands of felt pads would be needed to absorb anything below high frequencies. I thought of the egg box treatments and carpet on walls/absorber panels in some studios.
 
I did smile at the thought of plastic piping hanging from the walls. Tuned resonators without damping would be like having drone pipes or strings (like those on the guitars I have) storing and releasing energy in the listening room. What notes, or indeed key, would be best for different types of music?
 
Listening to speakers is like recording an acoustic instrument. You are listening to the room as much as the source. Real rooms and recordings can sometimes benefit from a little EQ in my opinion.
 
Has anyone tried fitting isolating spikes to their listening chair and footwear to control the structure borne LF energy? If so what was the best material? For those about to mock...
 
However it was the playful spirit of the article and open minded approach I respected.
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: tg [RIP]
Date Posted: 16 Sep 2010 at 11:21am

You are dead right there - Graham does indeed deserve a little respite.

However poorly it may have been executed, my intent was to provide some of that by means of a little levity as you have correctly observed.

Only time I have tried spikes on my shoes was when playing golf, I found them extremely beneficial in that application Wink



Posted By: Fatmangolf
Date Posted: 16 Sep 2010 at 4:27pm
tg, you were thinking the same thing I was about the spiked shoes LOL I risk going Krabby Patty by saying I also play golf.
 
Back on the tone/tweaking theme, my avatar is a photo of a tweaked ribbon microphone. So I think it isn't just h-ifi!
 


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: Graham Slee
Date Posted: 17 Sep 2010 at 12:22am
Originally posted by tg tg wrote:

Aren't you supposed to be building some sort of bomb shelter for your new hi-fi rack or designing an equivalent performance alternative to the lightspeed attenuator for the new preamp or something ?

The rest of us can do the silly tweaking and chattering stuff to keep ourselves amused while we wait. Wink



Picture of crater being filled by Robert (Bob the builder...) and Phillip



And Robert in his day job...



Can they fix it? I bl**dy hope so... Wink


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: Graham Slee
Date Posted: 17 Sep 2010 at 1:32am
Actually I'm just making appearances here at odd times of day as I wind down from one chore before I begin another or fall asleep...

At the same time as Bob and Co are building the "silo" for my hi-fi rack Stern%20Smile... Wink, I am having to consider the most effective soundproofing not only for the "bomb shelter" but for the adjoining fence, and doing the rounds of the soundproofing websites I stumbled upon a device widely used in studios called a "bass trap". The corners give the most concentrated bass of the studio/room and absorbent material or a more elaborate solution is used to counter it. I wonder if that could be the reasoning behind gluing felt pads close to the corners? Mind you, I wouldn't have thought three felt pads sufficient - perhaps it's a joke?Big%20smile


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: Fatmangolf
Date Posted: 17 Sep 2010 at 8:27am

Hi Graham, bass trapping will alter the room acoustics reducing prominent low frequencies (room nodes) caused by the room dimensions. It is usually absorbant material (like high density FR foam) in the corners and tuned absorbers (membrane/panel in front of depth or air like a drum but with Rockwool or similar material inside).

Generally the depth of the absorbing material sets the lowest frequency it can absorb, so felt pads of a few mm thickness would need to be layered (hence 10,000's needed) to make any difference below high frequencies.
 
Bass trapping will control bass bloom on certain notes. It won't probably won't give any sound proofing benefit as that requires the listening space to be isolated from the outside world. For high volume listening that means a room within a room. There are resources on soundproofing on the net and I can post some more info later if it would be helpful.


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: tg [RIP]
Date Posted: 17 Sep 2010 at 10:20am

I would imagine that the felt dots in the corners would effect a fairly specific range of high frequencies if anything.

I would also observe that there is a world of difference between tuning the acoustic response of a room for a reasonably flat response at one or two specific places using fairly carefully positioned sound sources and reducing the amount of sound carried to neighbours from a workshop.  Pretty certainly some frequencies/ranges will carry more than others and differing materials may be required to dampen their transmission, double layer gypsum board with rockwool or similar of perhaps 50 - 75 mm thickness between has been used IIRC - but acoustics specialists will be much better informed.

Phil sounds a very proper name for someone placing concrete in a hole. Wink



Posted By: jonclancy
Date Posted: 17 Sep 2010 at 11:34am
Was that a vindaloo-grade septic tank, Graham?  Wink

I've been tied up the last few days, but following this thread from afar.  I fully intend to go back and read Thor's article in more detail, rather than just scanning it.  I can see how placing the felt dots might interrupt room resonances, and that a coat of laquer might add damping to an item.  I'm not sure it I could detect the differences.  However, in the name of science, I might buy some felt pads when I'm next in the DIY shed.  I think our acoustic piano, guitar, cd racks and other furniture might have a greater effect!

Cheers

Jon



Posted By: Fatmangolf
Date Posted: 17 Sep 2010 at 10:15pm
It was certainly a big hole. Not sure if it rated vindaloo, certainly above madras and short of phaal.
 
Back to tech. I think the worst rooms I have heard are rooms with uneven treatment. That is rooms that are deadened in one part of the sound spectrum but reflective/live or even resonant in others. I mentioned egg box rooms earlier so lets move on from the obvious damped treble.
 
Most living rooms are acoustically dead with some bass bloom that can be tamed but have some reflections leading to ringing or pinging. With no music playing, try clapping your hands and listening to the room. If you have a flatscreen TV (great otherwise!) listen to the slapback echo off it. That's real rooms for you.
 
Anyway the problem is that a real room will respond differently to different frequencies. This is about the transient response and time decay. A plot of an untreated room would show how some frequencies sustain and boom or ring compared to others. With furniture and decor it is less obvious but the room's response will vary with frequency. It really is all the other stuff we have in real rooms like Jon Clancy wrote.
 
Unless you have put your speakers in the worst place in a terribly proportioned room (try a cube of 10 feet/3 metres sides) the distribution of the stuff in the room is more likely to change the sound.
 
And some Soundproofing options:
1) close your (double glazed) windows
2) don't pressurise a small (up to 30m2) room with floorstanding speakers and sub woofer
3) build a listening room inside your room with inner walls, absorption and a floated floor
4) talk to neighbours about acceptable times for loud music and antisocial times
5) listen to headphones when you want to crank it at night
 
I would suggest the last two "treatments" are actually the most effective.
 
Jon


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Jon

Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.


Posted By: daronharvey
Date Posted: 02 Nov 2011 at 12:05pm

As a newcomer to this forum, I thought I would chip in with some thoughts and observations of my own.

A recent house move has meant that I'm now in the enviable position of having a dedicated listening room... or so I thought. My system (old, but lovely... some of which I've had for a couple of decades!) includes a Linn turntable, Arcam CD92, Naim pre and power amps, and some Monitor Audio GR60 speakers. The room, however, is not playing ball. Far too much bass, and a lot of clarity being lost, especially when the music gets busy or loud(ish). It sounded far better in the old house, in a room shared by other stuff including the TV, etc.

Some recordings do actually sound great, while others can only be tolerated by rolling off the volume. This sometimes means that I have to roll off the excitement too, which is defeating the object of why I put the track on in the first place.

Given that what goes down on a recording can be greatly influenced by what the recording engineer hears through the monitor speakers in the studio, meaning that bass-heavy monitor speakers could result in a bass-light recording (and vice-versa), I often feel that regardless of how detailed or not my hi-fi gear is, and in that I include my headphones (Grado SR80's), my enjoyment is compromised by a little too much or little of the sound characteristics which I have no control over.... and kinda wish I had!
 
I dont suffer from neighbours in noise polution sense, and I'm considering what... with the permission of my better half... I can do in my listening room which isn't going to cost me a packet (which quite frankly I dont have). Headphones now seem to be playing a greater part in my listening than even, which is why I ended up on this site in the hope of finding something which could live comforatbly along side my other old faithful hi-fi gear for years to come. I feel I'm in the right place!


Posted By: Graham Slee
Date Posted: 02 Nov 2011 at 1:41pm
Quite a lot can be done with speaker positioning - pulling them a metre away from the back or side walls helps a great deal. Also play around with toe-in or toe-out - I find distant speakers work better toed-in slightly and near-field speakers work better toed-out slightly. Stands should be really solid to prevent boom - filling hollow metal stands with sand increases mass that the bass energy finds difficult to shift. If your walls were mirrors you'd see reflections of your speakers from your listening position - the sound bounces of at these reflection points and your ears can be confused during busy passages. Try to arrange soft furnishings to soften these reflections. Wall rugs, heavy curtains and even pictures printed onto acoustic deadening panels can be employed. Ceilings can be a problem too - best have the speakers at a mid point between floor and ceiling, but if the reflections are really bad then the only thing you could do is stick a Sonex Wiltec tile on the ceiling half way between speakers and you.

A change of headphones may also help not forgetting a change of headphone amp Wink


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That none should be able to buy or sell without a smartphone and the knowledge in how to use apps


Posted By: daronharvey
Date Posted: 02 Nov 2011 at 3:35pm

Hi Graham

Thanks for the suggestions on the speaker positioning, etc. For the size of the speakers, it could be that the room is a little on the small side, but this is what I have to work with, and I'll give it a shot.

The Monitor Audio GR60's are 110cm tall, and are floor standing. Currently they're standing about 8" from the rear wall, and 12" from the side walls, with a slight toe-in. I'll give them a try by moving them forward and inwards, but I'm compromised a little with there being doors at either side of the room cliose to where the speakers are currently. I'll also look out for that Sonex Wiltec tile you mentioned, although I'm keen to focus my next spend on a headphone amp, so what this space.

Incidentally, I did consider upgrading the Grado SR80's to SR225i's or SR325i's, but as MP3 is my only headphone source (albeit a damn good MP3 player), I feel I could be spending money in the wrong place by upgrading my 'phones, and should be giving some attention to the source and therefore making the best use of my Arcam CD92

I appreciate the feedback, Graham... thanks!




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