don't mean to sound pretentious, but I believe a Voltaire quote is relevant here:



http://www.famous-quotes.net/Quote.aspx ... f_the_good



I think what you have achieved is already very good, and AFAIUI can always be upgraded at a later date when manpower/time/energy is more plentiful.

Be sure that precipitous pile of blue fill won't collapse in event of an earthquake.

I guess that'll be part of v2, or maybe it's better secured that it appears.

It'd be a shame to die shouting silently under a giant mound of blue fill.

Isn't room gain a significant cause of the increased bass energy? 16" of fill won't do much at, e.g., 50Hz.

yup.

This discussion really has not ventured far at all in the last 48+hours, I would like to add something.... Temps...... it's phucking hot here on the outskirts of London, My temp for the CPU was 29C about a month ago and now it is 35C (and feels much worse....much, much worse.)

Anyway back to the point, testing without any kind of air-con, portable or otherwise will be impossible, simply because the air temp will raise quicker and to a higher potential than in reality. Does this mean that SPCR will continue to test PSU's in different rooms (as they have always done), or will the room eventualy be outfitted with a stupidly expensive cooling/fresh air aparatus that it can be used for all testting purposes.?

Either way I am looking forward to the review of the long overdue Antec Fusion Max


Andy

(Sorry if Mike has stated otherwise and I missed it, I haven't read through the thread in its entirety). Isn't the plan to keep the door open during testing, and then only close it for short periods of time to do the noise measurements? I'd tend to think heat would not become an issue if this methodology was used.

I'll echo what others have said about shooting for perfection, I don't want this endeavor to send you to the loony bin Mike (kidding of course, but in all seriousness, it seems like this is becoming increasingly stressful for you). What you have now is a significant improvement over the old testing room, I honestly see no reason to start on v2 so soon. It's definitely something that can be considered in the future, but you've put so much work into the current chamber, I'd say you deserve a break.

Not True. Thermal testing can be done in the room -- with the doors open. The only time we need to close the doors is when we're measuring / recording the noise. There's plenty of air volume in there -- it would take a big PSU to heat it up appreciably, and only if the doors are closed.

Vancouver has a much narrower range of temps. During most of the year, the temp in this room -- before all this added insulation -- has ranged 19~25C. Now, I bet the range will become a bit narrower.

As for the Fusion Max, we'll do a review when we get a sample.

Honestly, Mike - I have to agree with previous commentators - it's already well past that point of obsession. As a lazy reader who can passively enjoy your hard work with zero effort on my part, I'd love to see the spectacle of you building a massive concrete anechoic bunker in your backyard. But that wouldn't be fair to expect after all the effort you've already put into establishing a standard of excellence far above and beyond any other hardware site on the web.

Even at the start of this project / article, I thought, "Uh-oh, Mike's finally lost it and gone over the deep end." So it's utterly wrong for any of us to criticize and suggest anything beyond the degree you've already gone to, except for the sheer fun of daydreaming about having such a room. But in reality? Nobody else has even come close to SPCR, even before this project, and version 1.0 has already taken it to the next level, light years ahead of any conceivable competition. So don't worry, enjoy the fruits of your labors, and rest assured that any remaining suggestions are nothing more than lazy whining / fantasizing on the part of we spoiled readers.

Ever grateful and admiring,

golemB

Mike, should you ever start v2.0, an isolated floor could include a adaptation of a technique used to mount big telescopes in observatories worldwide - a pier mounted underground some distance and isolated from the surrounding structure and upper layers of soil - sort of a pier mounted in the bottom of a well. This could be done with well digging equipment and Sonotube pillar forms. I suppose the effectiveness is somewhat affected by subsurface geology, but is very effective nonetheless.

Just another thought...

Larry

For once it's warm in this cursed city and you complain?

I'd simply put any PSUs in a box for high temperature testing.

Very impressive project. The kind of thing that warms the cockles of my heart to read.


I think Mike's body temperature is more of a concern. His perspiring nature could be jeopardising those temp readings for all we know.

We're back to review work, finally. The acoustic chamber project has been deemed a success after our first real work with it yesterday. In a nutshell, a PSU tested in the usual way had a minimum SPL of about 21-22 dBA; the ambient SPL in that room was around 17~18 dBA. At about 250W load, it measured ~26 dBA. At full tilt, it reached something like 37 dBA.

In the acoustic chamber, with ambient SPL of 11 dBA, the minimum SPL of the PSU turned out to be 18 dBA. The higher ambient of our original test room was adding to the overall SPL reading, incorrectly raising the SPL. But at the 250W and maximum power levels, the SPLs in the chamber matched the SPL in the original room exactly. This is exactly as it should be.

One goal for the chamber was to make our low SPL readings more accurate, and that's clearly happened, without any sacrifice of accuracy at higher levels. I expect that as long as the SPL is 5~6 dBA higher than the noise floor of the room, it's accurate. When we reach SPL levels <15 dBA, it will hardly matter anyway -- we can simply say it's quiet enough to be inaudible under almost all conditions.

does this mean you're going to retest a lot of stuff? like you did when you tweaked the fan testing method?

Awesome

Now the only question remaining is: Did you clean up the house b4 your better half returned?

uhm.... in process. I have 2 days.

Only a few things, the ones we use for reference. Too much work to do the rest -- and the rankings won't change at all >90% of the time.

Maybe, maybe not. The review for the PSU Mike mentioned is being written as we speak. To give you a bit of a preview, there weren't any "surprising" sounds from it like we've had from other samples. Some samples have had buzzing sounds, or strange over/undertones. In this case, putting them in the quiet room can help identify what's causing that problem. On the flip side, when Mike and I were running the audio tests, we noticed a spike in the 15kHz range when it was in the room. This was, however, down at -20dBa, and therefore never showed up (and was never noticed) by us while we were testing it.

Like Mike said, anything below 15dBa is pretty much silent in most situations.

Edit - Mike beat me to it.


Edit 2 - Another thing to point out. The chamber is very different than any other room I've ever been in. Mike's office/lab is about as quiet of a regular ambient noise as you're probably going to get (minus the furnace and fridge when they're running), and a lot of the work we do is based on the percieved noise. Sure, in the room you might be able to tell that a Nexus fan is running at 5V, but outside there's pretty much no chance. In this way, there isn't really much value to retesting everything, aside from a nice thought experiment (which would take a VERY long time).

I don't see how you are going to avoid retesting a chunk of the better items.



So you test a new PSU and it tests as 18 dBA min instead of 21 and you want to make a comparison vs the best of the past PSUs. It won't be a fair comparison unless you retest the ones you compare. You'll get confusion and complaints if you don't make the comparison or if you make an unfair comparison.

You definitely don't need to retest every item on every recommended list but you'll have to test the high fliers just so people can make comparisons with newer reviews.

It's often not possible because we no longer have the sample (it's a huge storage issue to keep anything, it just piles up) and because of the time/effort issue. There are some we'll redo, but we'll be advising people in general that the qualitative analysis is ALWAYS the most important, and to subtract some 3-4 dBA from anything which got below ~23dBA in the past. Our recommended rankings are unlikely to change at all, and when new items come in at ~16 dBA, we'll set it below the ones that got 18 dBA in the past... but actually, anything that got below 20 dBA in the past we'll try to retest if we can.

wow, talk about a fire hazard 0_0

Not at all. It has exactly the same same ratings as fiberglass insulation, for which it's a safer, much less toxic substitute.

Congradulations Mike for finishing the project and starting testing. I acctually thought you wher done when I saw your first rms A figures a few weeks back.

I really think this new lab, along with lasting proven testing methods, is proof this review site is way ahead of the rest when it comes to sound measurment.

I think it would be smart to retest/update the dbA numbers for the top 2 or 3 items in the fan and PSU categories, so it would be a fair comparison with any new review. Changing the room essencially means you now have a new testing method and will need to level the playing field.
I don't expect full testing of all reviews nor do I believe anyone is. Just updated SPL measurments for the leaders of the bunch.

For instance if a single Corsair PSU (say HX520) would remeasure as 18 dbA in the new room, you could say it represents all Corsair PSUs drop in noise level measurments from 22 to 18 on idle, while the rest of the review essenciallys stay the same.

As a frequent computer builder and a sound studio owner I love what you did, and even more so, the fact that you did it.

Mike - Great work with the testing lab. I would love to see more pictures of what it looks like now.

It's great to see all the words of appreciation for the work on the chamber. It's always a bit of a surprise to see how many people in the world care about quiet.

An article on the project will be posted soon, probably along with some recordings and a few measurements -- before and after -- to explain how new test data will compare with old. Obviously, the sound characteristics of the products will not change one iota, but our measurements and recordings will. As mentioned earlier, it will only impact things that measured <23~25 dBA before.

So let me add my appreciation to the pile. :)
Unnecessary noise pollution is one of the mindless evils of our society, and I'm deeply appreciative of the help this site brings people who try to combat it in the workspace and at home. Never doubt that its influence extends beyond the immediate readership.

I have had music and sound technology as an interest for decades, to the point of making binaural recordings, designing and building headphone amps, and so on. If ever such experience would be in demand, I'd be happy to contribute.

jgp

I was working as a tech at a hospital for a time and they where building a new wing and it had a x-ray machine room and i got to see the 1/2 inch thick lead sheets they put up on the walls. It was very industrial looking looked more like 6x6 foot scrap pieces of lead. The room was quiet though.

I don't think that Mike would ever have the chance to dig a well through the middle of his house, then put a pier in it. However, what WOULD be vaguely practical is to pick up surplus CB antenna magnets for example. If you arranged enough of them, you'd be able to suspend the room on a cushion of magnetic repulsion with no contact with the ground. Kind of like maglev trains. Like maglev trains, it's probably cost-prohibitive for general use.

In case you missed it, on p.5 of the review of the NesteQ 700W PSU, there's an MP3 recording comparing the ambient in the hemi-anechoic chamber vs that in the live test room used previously for PSU testing. 11 dBA vs 18 dBA. Direct link to MP3 here.

I didn't miss it. I'm just sitting here quietly anticipating the further goodness of future reviews.

I'll add my voice to the (quiet!) chorus. Nice to see the chamber's done. Nice we'll be seeing new reviews too .

Oh and Mike, there is lots of us quiet-freaks out there but usually we are not heard from a lot (sic!).

I'll be doing a new quiet (I dare not say silent) build somewhere in october and I'd like to thank you and the rest of the staff for feeding me info I can't get anywhere else on the topic of silence. (Items so far acquired after tests here: p180b, enermax modu82+ 625W and S-Flex E fans)

To give as good as I got I will be trying to make an extensive write-up and a lot of photo's of it and share it back to the community here (it'll be my first time modding a brand new graphics card....bit scary really)

Again, thx for all the work

Aelek