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Speaker Isolation - Fact Or Bullshit? - We Have The Results Of Our Poll And The Case For And Against

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Off-the-shelf monitor isolation products do indeed look the part but how can we know for sure that these types of tools work and if they do, how great are the benefits to our monitoring? Are they glorified gadgets or are they essential for our monitor performance?

In a poll, we asked “Do you use speaker isolation? If so which type do you use?” and in this article, we analyse the results and also ask 2 experts do put the case for and against speaker isolation to see if speaker Isolation is Fact or Bullshit.

The Results Of The Poll

In the article, What Type Of Speaker Isolation Do You Trust In Your Studio? Vote In Our Poll, we asked you to tell us if you use speaker isolation and if so which product you used and here are the results from the poll…

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Only 11.53% of the respondents currently don’t believe that speaker isolation works, the rest do believe that it works and the two most popular solutions are Foam Pads with 34.11% and Isolation Desktop Stands with 26.12%. If you want to know more about each of the solutions then check out our article where we give more details on each of the different solutions.

So the question remains as to whether speaker isolation is fact or bullshit and to help answer this we have asked two experts to present their case.

In Favour Of Speaker Isolation - Dave Mastrodonato from DMSD

Speaking in favour for speaker isolation is Dave Mastrodonato from DSMD. Back in July 2017 James Ivey reviewed the DMSD 60 Speaker Decouplers and this is what James said in his review…

“With my Trinnov room correction system, which runs my Focal Twin6 BE's and my sub, in bypass, the image was really very good. The bass still felt tight and accurate and not "flabby". When I re-calibrated the room with the DMSD decouplers in place it was as if I had a new room. There it is again, the OMG effect. These things work. The Twin6 BE is not the cheapest monitor on the market but nor is it the most expensive. My list of "rig tester" tracks sounded amazing. The stereo picture was amazing. Yes, the Trinnov was helping but the DMSD 60s were taking the sound quality and my experience to another level. You really have to hear these things to believe it.

With the Dynaudio LYD48s, the effect was even more pronounced. With the speakers just sitting on the meter bridge of the console I was losing a lot of bottom end. When I put the LYDs on the DMSDs they sounded tight and punchy and had a lovely top end air to them.”

Dave from DSMD agreed to put the case for the benefits of using speaker isolation and this is what he wrote. Because Dave’s mother tongue isn’t English we should declare that Mike has reworked Dave’s original to improve it from an English grammar perspective which Dave has approved. Over to you Dave…

Thank you for asking me to contribute to this follow up article on speaker isolation as I want to make listening recording easier whether than it is in studios, concerts or in the home.

I have been a music producer and sound engineer for many years, At the same time my other big passion is aviation engineering studying and working for about 22 years as a product specialist.

In this work, my clients often ask what materials are best to use for certain applications and how to solve problems such as the transmission of vibration between objects and surfaces.

This engineering experience especially in the area of vibration management has proved very helpful when in came to the issue of decoupling loudspeakers. It was necessary to create an insulating support but at the same time not to distort the singular characteristics of each acoustic diffuser, whilst also maintaining a totally neutral surface on which to place the loudspeakers that would respond in the same way in any condition.

It was from this that the DMSD 60 Pro was born. I designed with custom materials all with very high anti-vibration characteristics, but at the same time, stable in any situation to produce a calibrated mechanical support that always responds in the same way proportionally even with different weight loads.

It needs to be a decoupler that is able to reduce the halo of low frequencies, which is often described as 'the Dirty Sound'. I also wanted to produce a decoupler that would be able to attenuate reverberation times.

Throughout the development process we carried out tests around the world, as well as comparative tests on most of the competitive products, and in these tests we have always found that our DMSD 60 Pro have come out on top.

Our products are used by esteemed Engineers such as: Michael Brauer, Brian Vibberts, Tony Maserati, Takehito Masui, Satoshi Osohi, Seigen Ono and Pierpaolo Guerrini to name but a few.

Below are the results from one of our tests showing the differences between the before and after when using the DMSD 60 Pro.

DMSD Speaker Isolation Frequency Response Test Results. Click on the image to see a larger version

DMSD Speaker Isolation Reverb Decay Time Test Results. Click on the image to see a larger version

Against Speaker Isolation - Ethan Winer

Speaking against the need for speaker isolation we have Ethan Winer. Ethan came to our attention when community members referred to him and his work in this area in the comments in our article with the poll. Here are some of the comments…

  • “Ethan Winer has tested several products and finds no real benefit in using these. I use Isoacoustics but I too am not convinced that they are better than a simple riser.”

  • “Ethan knows his craft but I too use the Isoacoustic stands. The change in sound I hear is probably due to position and a difference in reflection. I also like that I no longer feel the bass vibrating through my argosy console stand.”

  • “That guy is like a cult leader for the “internets myth buster” set. He’s usually wrong.”

  • “I've followed him and read his books. He is usually right. If he is wrong you have to prove it with science, not opinion. If his methods are flawed he is open to hearing from people and will consider other views if you can show it scientifically or tell him where his methodology is flawed. He is very successful at what he does including his real traps business because he thoroughly understands engineering and acoustics. His knowledge is very extensive and impressive. As an engineer for over 30 years myself, I personally believe few pro engineers in our industry could read his audio expert book and fully grasp every concept he covers. If you think he is wrong go to his site a review his test and show where it is flawed.”

In case you haven’t come across him, Ethan Winer has been an audio engineer and professional musician for 50 years. His Cello Rondo music video has received nearly 2 Million views on YouTube and other web sites, and his Focal Press book The Audio Expert, now in its second edition, is available from Amazon and Ethan’s own web site. Ethan is also a principal at RealTraps, manufacturer of high quality acoustic treatment.

Over to you Ethan…

I’ve been an audio professional for fifty years, and I’ve seen some amazing products. But I’ve also seen plenty of useless junk—products I call “placebo-based”—with advertisements that rely on user testimonials rather than facts and measurements. For years I accepted that loudspeaker isolation is useful, even before isolation products existed. The theory is that a speaker’s cabinet vibration can transfer to the surface it rests on, causing various problems. The first justification for isolation I recall is that sound travels through solids faster than through air. So sound from the speaker reaches your ears via two paths, and the arrival time difference creates a response anomaly called comb filtering.

Now that products exist we see claims that vibration causes a shelf or desk to resonate, which “smears” the sound extending decay times at bass frequencies. Another claim is that isolation improves transient response and overall clarity by holding the speaker still rather than letting it rock back and forth. Yet another feature often claimed is that the isolation device can be tilted, to better aim the speakers at your head. But angling is best avoided because tweeters should be at ear height. Otherwise small head movements put you off-axis changing the response you hear.

However, the real issue is that competent speakers don’t vibrate enough to cause real harm. I say “competent” because some cheap speakers are flimsy and may flex or vibrate as the woofer cone moves in and out. But competent speakers don’t do that. Even if you can feel slight vibrations when touching the side of a speaker cabinet playing loudly, it’s still a much lesser sound source than the extreme motion of the woofer cone. So why do many experienced listeners swear they hear an improvement with these isolation doo-dads?

One reason is simple placebo effect, or expectation bias. Human hearing is much less reliable than many realize, and there’s no easy way to do a fast A/B comparison let alone a proper blind test, especially with large speakers. However, it is possible for an isolation stand to change the sound. Simply raising a speaker one inch has a surprisingly large effect on the response reaching your ears. So the sound really did change, but not for the reason you thought!

As a skeptic and audio realist I decided to test speaker isolation for myself, which turned out to be surprisingly difficult. If you want to learn more then do check my article Testing Loudspeaker Isolation Products in which I describe in detail the tests I undertook and the results from those tests. Unlike isolation vendors, I actually measured the sound in the room rather than how well the devices block vibration. We already know that rubber provides mechanical isolation, but that’s moot if the speaker doesn’t move. It’s no surprise that isolation vendors never show how the sound changes in the room.

Room measuring software such as Room EQ Wizard is extremely sensitive, and can display differences much smaller than any human could hear. Once speaker height was accounted for, I measured no meaningful difference between six different isolation devices versus none. So if a vendor tells you to “just listen,” or claims that what their product does can’t be measured using current knowledge, they’re either incompetent or dishonest. If these products really did improve the sound, isolation sellers would offer hard proof instead of glowing testimonials and data that might seem impressive but is actually irrelevant.

No vendor I know of has ever produced valid measurement data proving their product works, and I have data showing that it doesn’t. The night and day difference vendors claim would be clearly visible in standard room measurements. So if an isolation device really improves the sound, let’s see some data! But it must be real in-room measurements, including a detailed explanation of the test method with photos of the setup.

These graphs show the frequency response with and without each isolation device. Blue is No Isolation, and Red sequences through each device as labeled.

You Decide

There you have it. Thank you to Ethan Winer and Dave Mastrodonato for taking the time to share their thoughts and experiences with us.

As promised, our two experts have presented the case for and against speaker isolation and that is where we are going to leave it. We are not going to draw any conclusions from these presentations, we are going to leave it there and allow the evidence to speak for itself so that each of you can make your own mind up. Please do share your thoughts, observations and experiences in the comments below.

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