SHL5s balance in my room

[EricW]

Evidently not Alan, otherwise there wouldn't be a 5 page thread on the other forum (nor the 2 pages on here).

It's logical sense to you because you have a thorough understanding of it, nothing to do with 'common sense' - I find your post quite patronising.

I appreciate your help nonetheless.

I think jack667 is undergoing the same learning process Alan describes in his posts, just perhaps a bit later in life. The difficulty with that (as I know from experience) is that there's more to unlearn as well.

Also, I think that one of the consequences of learning something well and thoroughly is that one internalizes to the point that it seems "natural", it becomes part of you, and it consequently can be difficult to understand why something that to you is as obvious as sunshine is something that may be more difficult for others to grasp.

To jack667 I'd say, Alan's manner of expression can sometimes seem a bit severe, but it's all a consequence of his intellectual passion (IMHO). The last thing he'd ever do is patronize anyone, much less a HUG user.

[A.S.]

... I'd never state that the person must use common sense to figure it out (which in this day and age - everyone must learn something so basic at school, right?) ...

We are talking at cross purposes. I wouldn't have invested hundreds - thousands of hours here on the HUG if I believed that science was as simple as the application of a little common sense.

What I am saying is - and I repeat - the failure to apply comparisons (let's call it common sense) between the sort of issues that occur over and over again in home audio with life experiences outside the listening room in the real world creates a knowledge void filled with snake oil. One serious issue with the internet is that it creates the instant expert but it takes real effort and (that word again) 'common sense' to 'smell' an opinion that just doesn't seem to fit with ones real-life experience outside audio. Science is science and it must be consistent throughout the universe, so if you read that an aerosol spray dusted over your equipment will transform the sound of your system, does that square with your observational experience in the real world outside the listening environment? What other example can you draw on of the transformational power of an aerosol except perhaps in a health spa? If it does, then for you the magic aerosol is a must-have regardless of what others say. If it doesn't then your 'common sense' rejects the very notion of sonic aerosols.

It's not the arrival at the technical truth by the application of common sense we are stumbling over - that couldn't be expected of any non-specialist in a science field - it is the rejection of what are exceedingly unlikely to be technical truths by the application of (that word again) common sense. That's quite a substantial difference of emphasis.

Please remember one thing that may not be obvious. When I reply or comment here, I am not just attending to the specific issue for the specific respondent, I am trying to present a broader, simplistic, more universally applicable response (including this one) that will save me having to re-visit the issue again as I am not able to devote routine time here.

I hope that completely resolves any misunderstanding about common sense.

P.S. The acid test of my suggestion that it is the failure to apply common sense to compare and contrast with real-world experiences that leads us up the garden path would be to chose a subject we may mutually know little or nothing about. Plenty of choice for me: wine? Or nuclear physics? Or fish husbandry? Construction of the PostScript language perhaps %%? Let's stick to wine. We set off with an objective to find a really great wine, and we start mixing with wine experts. At first, we absorb knowledge like a sponge: it's all new and exciting, but we reach a point where contradictions and doubts start to creep in. One says that his flavour is certainly due to the unusual soils in his vineyard irrigated from a clean stream. Another says that, no, the secret of his great wine is that of the full moon shining on the bald heads of the peasant workers as they pick the grapes after midnight. A wonderful romantic story! You can see it in your mind's eye! But really, a little application of common sense surely tells you - even if you know absolutely nothing about irrigation or grapes - that the moonshine tale is nothing more than advertising puff. Or so it should. But that's not how audio works.

[jack667]

I think jack667 is undergoing the same learning process Alan describes in his posts, just perhaps a bit later in life. The difficulty with that (as I know from experience) is that there's more to unlearn as well.

Also, I think that one of the consequences of learning something well and thoroughly is that one internalizes to the point that it seems "natural", it becomes part of you, and it consequently can be difficult to understand why something that to you is as obvious as sunshine is something that may be more difficult for others to grasp.

To jack667 I'd say, Alan's manner of expression can sometimes seem a bit severe, but it's all a consequence of his intellectual passion (IMHO). The last thing he'd ever do is patronize anyone, much less a HUG user.

I'm aware of this - it was just an opinion.

I really do love Harbeth products, and part of the reason I'm here is because I have actually wasted my own money on several different types of speaker without ever being truly happy.

Now I'm at the end of my search, the acoustics issue is my last and final hurdle.
Thanks guys!

[jack667]

We are talking at cross purposes. I wouldn't have invested hundreds - thousands of hours here on the HUG if I believed that science was as simple as the application of a little common sense.

What I am saying is - and I repeat - the failure to apply comparisons (let's call it common sense) between the sort of issues that occur over and over again in home audio with life experiences outside the listening room in the real world creates a knowledge void filled with snake oil. One serious issue with the internet is that it creates the instant expert but it takes real effort and (that word again) 'common sense' to 'smell' an opinion that just doesn't seem to fit with ones real-life experience outside audio. Science is science and it must be consistent throughout the universe, so if you read that an aerosol spray dusted over your equipment will transform the sound of your system, does that square with your observational experience in the real world outside the listening environment? What other example can you draw on of the transformational power of an aerosol except perhaps in a health spa? If it does, then for you the magic aerosol is a must-have regardless of what others say. If it doesn't then your 'common sense' rejects the very notion of sonic aerosols.

It's not the arrival at the technical truth by the application of common sense we are stumbling over - that couldn't be expected of any non-specialist in a science field - it is the rejection of what are exceedingly unlikely to be technical truths by the application of (that word again) common sense. That's quite a substantial difference of emphasis.

Please remember one thing that may not be obvious. When I reply or comment here, I am not just attending to the specific issue for the specific respondent, I am trying to present a broader, simplistic, more universally applicable response (including this one) that will save me having to re-visit the issue again as I am not able to devote routine time here.

I hope that completely resolves any misunderstanding about common sense.

P.S. The acid test of my suggestion that it is the failure to apply common sense that leads us up the garden path would be to chose a subject we may mutually know nothing about. Plenty of choice for me - shall we say, wine? Or nuclear physics? Or fish husbandry?

Haha. Understood. I wholeheartedly agree with your point about 'Internet experts' - there's a fair share of b.s. out there.

Cheers Alan. Like I said before, if the digi-eq helps me then I'd be more than happy to share my findings.

[A.S.]

Would you like to borrow my Behringer? It is slightly modified in that I drilled an extra hole on the back and made a socket for a foot switch to turn the EQ on or off by remote (foot) operation.

The reason I did that was because I was working on a speaker design a few years ago, and the speaker had a small bump in its frequency response, as measured with the test equipment. It slightly offended me to see this little bump in an otherwise very flat frequency response curve. After a lot of dithering about unsure what to do for the best soldering passive crossover components on and off (which meant getting up from the hot seat, soldering both crossovers, sitting down again many seconds later) I decided to electronically eq-it out and see if it there was any audible difference, or even improvement (or worsening).

So, sitting in the hot seat with the EQ box wired-in between CD player and amp, I could operate the foot switch without moving and hear the instantaneous X/Y comparison of eq in v. eq out.

[Pluto]

As mentioned previously, I appreciate everyone's feedback.

Jack - I rather doubt that Alan is patronizing you, but look at this from the other end.

You provided a list of things that did not work, to wit:

• Speakers were lifted completely off the stands whilst music was playing
• Granite slabs were placed under the stands
• Stands were replaced with thin wooden stools, about 25" high
• Sofa was pulled out 50cm from the back wall
• Speaker placement changed
• Introduced a heavy rug on the floor

How does explaining a little about standing waves amount to being patronising?

I perceive a major problem these days is that true science - be it basic acoustics or electronics - is partitioned within an equal-size compartment in the audiophile psyche to the one that says "cabling changes the sound" and the one that says "CD players change the sound", the one marked "speaker stands make a BIG difference to the sound etc. etc. and it is this kind of thinking that drives the response you typically obtain on hi-fi forums. You have no doubt yet to hear the one about your proposed EQ solution which will "destroy" your music. The number of forum debates that appear to conclude that audio science is weak or incomplete don't bear thinking about, so it's hardly surprising that, sometimes, people seem to need putting back on the rails.

{Moderator's comment: As Alan said, posts he makes are *always* written for a wider audience. They may well be overly simplistic for 1% of the readership. But he is not chained to the PC 24 hours a day as an Audio Agony Aunt. This is a free (and completely willing) service in the interests of great musical satisfaction at home. Thanks.}

[jack667]

Alan, that's very kind of you. I wouldn't want to put you out, and I'm quite far away in London.

That's a great idea with the foot switch.

I figured the digital one would be best as it seems to have control over the full frequency range- I might be wrong though!

I'm a big fan of Behringer, whenever we've used their rack gear in the studio I've always been really impressed with the quality of their products considering the price.

Thanks

[Takis]

...if the digi-eq helps me then I'd be more than happy to share my findings.

What is the model name of the Behringer?

(Don't forget to tell as about your findings, pls).

[jack667]

Jack - I rather doubt that Alan is patronizing you, but look at this from the other end.

You provided a list of things that did not work, to wit:

• Speakers were lifted completely off the stands whilst music was playing
• Granite slabs were placed under the stands
• Stands were replaced with thin wooden stools, about 25" high
• Sofa was pulled out 50cm from the back wall
• Speaker placement changed
• Introduced a heavy rug on the floor

How does explaining a little about standing waves amount to being patronising?

I perceive a major problem these days is that true science - be it basic acoustics or electronics - is partitioned within an equal-size compartment in the audiophile psyche to the one that says "cabling changes the sound" and the one that says "CD players change the sound", the one marked "speaker stands make a BIG difference to the sound etc. etc. and it is this kind of thinking that drives the response you typically obtain on hi-fi forums. You have no doubt yet to hear the one about your proposed EQ solution which will "destroy" your music. The number of forum debates that appear to conclude that audio science is weak or incomplete don't bear thinking about, so it's hardly surprising that, sometimes, people seem to need putting back on the rails.

{Moderator's comment: As Alan said, posts he makes are *always* written for a wider audience. They may well be overly simplistic for 1% of the readership. But he is not chained to the PC 24 hours a day as an Audio Agony Aunt. This is a free (and completely willing) service in the interests of great musical satisfaction at home. Thanks.}

Not to continue this any further but remember I haven't spent a penny, nor did I intend to. I enquired about acoustic treatment, which was actually shot down by quite a few posters on the other forum as being insignificant in a room like mine that actually needs to be lived in.

Ok- let's wrap it up there. I apologise if I acted hasty - and if you've seen me on any other forums you'll understand how appreciative I am of people's free time in order to help.

[A.S.]

Attached (from 1951) is what I consider to be the best overview of the entire problem of room treatment. It was written for the public in an era when the public were not afraid of a few graphs. I've marked up (PDF comment in yellow on page 5) some observations that jump off the page to me that may be relevant to home listening rooms.

This is really the only technical paper you need to give you a damned good introduction to the subject. If the author, P. A. Shields is still alive, we applaud your clarity. The PDF meets the standards shown at the
foot of this web page.

>

[jack667]

Attached (from 1951) is what I consider to be the best overview of the entire problem of room treatment. It was written for the public in an era when the public were not afraid of a few graphs. I've marked up (PDF comment in yellow on page 5) some observations that jump off the page to me that may be relevant to home listening rooms.

This is really the only technical paper you need to give you a damned good introduction to the subject. If the author, P. A. Shields is still alive, we applaud your clarity. The PDF meets the standards shown at the
foot of this web page.

>

Interesting read - thanks.

Alan, which Behringer model was it you modified?

Thanks

[jack667]

Right - I had a solution today when using audio from the computer. I can run Soundflower & Audio Hijack Pro and EQ in real time digitally.

Based on just my ears (no room correction mic), the 31 band EQ looks like this:



That's an -11dB dip at 50Hz! It really is crazy how much boom I'm getting.

With a -3dB dip at 31.5Hz and 40Hz I'm getting quite an 'even' sound. The trade off being that they've lost some scale. Am I ever going to beat this? Haha.

Even still, EQ'd is better than no EQ - so I'm gonna get myself the Behringer, but I believe the DEQ2496 is also a 31 band EQ.. seems like I can't select exact frequencies? (like when I did the test, and the real troublesome freq was 52Hz)

Does anyone have any experience with this unit? http://www.behringer.com/EN/Products/DEQ2496.aspx

Cheers.

[thurston]

...I did try to tame bass issues just yesterday.

It is not really new stuff. I screwed triangular wooden frames (45cm x 60cm x 75 cm), filled them with rockwool and put them into the corners behind the speakers.
(of course some foil around it, therefore the wooden frames: I just was not able to put that around the rockwoll without any solid stuff to stabilize it)

With trumenduous results! Maybe they do not work below 50Hz (guess you can calculate how deep they can go by their measurements) but they obviously work within the frequencies that are included in the music that I listen to.

It is really unbelieveable how a tamed bass can sound. Virtually never heard that before.

I´d wish I would have concentrated on room-acoustics far earlier. It´s the holy grail!!!

;-)

{Moderator's comment: Please can we have some pictures of your design asap.}

[thurston]

Overview picture here

{Moderator's comment. Great. More pictures of the actual construction please!}

[thurston]

Now attached the pictures.

Picture One an Two showing the assembly.

2 pictures show the frames in the corner, with the frame partly filled on the second picture.

Have to mention that I luckily have a dedicated listening room. So the beauty of it all was only secondary.

On last (rather dark) picture you can see the end result with curtains
(which makes it look like a real cinema)


Picture One http://s14.directupload.net/file/d/2...9dpien_jpg.htm

Picture 2 http://s1.directupload.net/file/d/2806/ifu7q6g4_jpg.htm

[jack667]

Wow, that looks great Thurston!

[thurston]

...a little brighter (after that i´ll stop uploading more pictures)
;-)


@jack:
Thank you!

[STHLS5]

Thurston, Great work!

Did you wrap the rockwool with shrink wrappers? And did you fill up the whole compartment with rockwool? Thanks.

ST

[thurston]

@ST:

Exactly as you write!

[A.S.]

On behalf of the entire HUG membership, hats-off to thurston for showing genuine enterprise and innovation creating these DIY absorbers. They are designed according to the predictable laws of physics. They will and do work. Common sense* (those words again) tell you that to mechanically (physically) absorb/modify low frequencies you need acoustic mass (aka Rockwool). There is no alternative. None, other than reducing the amount of energy arriving at the speaker terminals (using some sort of in-line EQ) in those problem frequency bands so that they outputs less sound energy, which combined with the room boost at those frequencies, add together to a tolerable overall even sound. Thank god for German pragmatic engineering: we're making real progress on the room-tuning front at long last.

What would be excellent is to see some dimensioned DIY plans ... or even if thurston would consider making these available in kit-form for other HUG members?

P.S. No, I'm wrong and was corrected about this recently. Common sense tells me that if you want to absorb low frequency sounds, you need acoustic mass. Proof: nuclear test explosions are conducted far under the ground. Reason: the low frequency sound generated by an explosion is immense and does most of the damage to buildings via the sonic boom and wind-rush. No amount of 'decoupling' or 'air gaps' between the bomb and the surrounding air will tame the LF energy one jot. For that you have to impede the progress of the sound energy, and the best solution for that is solid granite.

In-room our best solution is to create friction between the air molecules wobbling about in the room. And that's how Rockwool works: it's a hairy, irregular, dense material through wihci sound waves will (reluctantly) try and pass through, and which progressively converts the motion energy in the sound wave into heat as it weaves its way like an exhausted athlete through the material until (in an ideal world) there is no energy to reflect back: the sound wave has dropped dead at the finishing line.

Sound waves, especially in the low frequency range are extremely powerful. That means they cannot be stopped with ease. How powerful? See here.