I personally recommend the Koolance FAN-12025HBK or FAN-12038HBK, which are 120mm fans that are 25mm and 38mm respectively, spin at a maximum of 2600rpm, utilize true dual ball bearing motors, push 107cfm/116cfm and 5.4/6.33mmH2O (airflow/static pressure), and notoonly have I found that they're made by either Delta or Sanyo Denkei (I have around 40 total of the two, 19 are Sanyo Denkei the rest Delta, but it seems like the newer ones, ie within the last 18mo, are Delta while older stock may be still SD; it doesn't really make a difference tho as I cannot tell a single difference until I find the OE marking), they undervolt extremely well down to about 1100rpm with 4 on a single channel of my Hydra PRO, but wait, hold the phone!
They're only $8.95-9.95 a piece!
My lab has an anemometer, and while not designed for PC fans, I have used it (shh) for such. I took a number of fans, but importantly I had a few baseline Delta, San Ace, and NIDEC fans to base the relative accuracy of the others off of (I had previously tested them and found no more than a 2.4 percent variation in airflow and pressure across 5 samples of each, and that's variations relative to the listed specs).
The Koolance fans are, believe it or not, the closest to advertised of any non-server fan I have ever tested! All listed are an average of 3 unless otherwise stated...
120x25 model - 108.221cfm and 5.453mmH2O (avg of five)
120x38 model - 118.048cfm and 6.399mmH2O (avg of five)
For comparison:
CM R4 - 46.834cfm and 0.770mmH2O
GT AP-15 - 50.035cfm and 1.988mmH2O
Bgears Blasters 140mm - 109.020cfm and 3.481mmH2O
Noctua AF-15 - 51.023cfm and 1.092mmH2O
Rosewill Hyperborea 140mm - 90.131cfm and 2.991mmH2O
Silverstone FHP-141 - 143.702cfm and 4.995mmH2O (if these were true 140mm fans they'd be gods)
Silverstone AP182 - 166.300cfm and 7.317mmH2O ( :O)
Silverstone AP123 - 35.220cfm and 1.588mmH2O
Silverstone AP141 - 43.803cfm and 1.138mmH2O
Cougar 140mm - 71.414cfm and 2.772mmH2O
Cougar 120mm - 61.001cfm and 3.104mmH2O
Noctua 120mm - 46.274cfm and 2.023mmH2O
Noctua 140mm - 51.700cfm and 1.336mmH2O (this and the one above are the "pressure" variants from the same time period of the D14 release)
NMB-MAT 3612KL-04W-B66 92x32mm - 59.515cfm and 13.904mmH2O
DATECH DS9238-12HBTL-A 92x38mm - 97.380cfm and 26.471mmH2O
Scythe SY1225SL12SH 120x25mm - 111.835cfm and 3.402mmH2O
Swiftech Helix PWM 120 - 67.988cfm and 3.081mmH2O
Swiftech Helix PWM 140 - 79.031cfm and 2.099mmH2O
Corsair SP120-PE - 61.925cfm and 2.891mmH2O
Corsair SP120-QE - 32.205cfm and 0.499mmH2O
Corsair AF120-PE - 78.400cfm and 1.193mmH2O
Corsair AF140-PE - 87.878cfm and 1.275mmH2O (yes, it was really 87.87878 *raise eyebrow*)
I can do some more if anyone has specific models they're interested in, and I also have them or someone sends it to me. The only downside is that as the lab is a university psychopharmacology research lab, absolutely no photography or removing data from non-personal terminals :/ That means while I can provide you with the data, I could lose my grant or even be arrested for taking a picture or screenshot. It is unfortunate, but in an industry with nearly as much money spent on corporate espionage as on R&D, I am lucky to get to use it for the fans as it sits now!
Also, as my side job is audio engineering (recording, editing, mastering records for mostly local musicians), I have a room-within-a-room in the basement that, along with 8" of 5 different types if soundproofing between the walls and some interior acoustic treatment, sitting on a 10" 8-layer soundproof mat which is then on a 1/2" closed foam board insulation and a 1" combined insulation/moisture barrier (due to having radiant heating, which is copper piping run under the floor which is raised off the slab in the basement, I had to set the extra 1" insulation to clear tubing on one side even though the room has nothing run below it).
The wire pass thrus are equipped with a giant ferrite bead around the edge of the rubber pass-through, which has 6 different layers of material that prevents sound leakage (plus, it's not straight thru, but offset at least 18" from one side to the other). All wiring I did myself, as I'm a bit ocd, and all of it is done completely from scratch (as in wires, cutters, crimper, crimps, fittings, etc). I use 12AWG CL2 oxygen-free copper stranded from Monoprice (I make enough to make a living doing this, and I have never heard a single difference between Monoprice and overpriced stranded silver coated unicorn feces like Audioquest and the other crazy, stupid stuff; there is more snake oil in the "audiophile", ugh hate that word, industry than anything else apart from homeopathy).
Oh, the primary speakers are Sonus Faber Cremona Auditor M's, Wharfedale Diamond 10.1's, KEF Reference Series, and what is most likely the single best deal in the audio industry, the Pioneer by Andrew Jones speakers, I love them so much that I find myself automaticallyrreaching for them when I have $8000 true reference speakers right next to them. I actually have all of the speakers, from both the first and second revisions, and take it from someone who does this professionally... A Pioneer SC-1222K or SC-1522K ($350-900 MSRP$1300/2300) receiver, 150ft Monoprice 12AWG wire ($40) with enough banana plugs for everything ($30), depends on the space but the absolute best is 3x FS51/FS52 towers for RCL ($150+75), 2 more FS51/FS52 for the primary surround channels ($150), a pair of BS41/BS42 for the Surround Back channels ($100, also a better choice for a center than the horizontal "actual" center if you absolutely can't do 3 towers), and either the BS21/BS22 smaller bookshelves if you need to save even more money but ideally another pair of BS41/BS42 for Front-Height/Width ($60/$100). Subwoofers are mostly either acceptable or garbage, excluding the incredible dual-12" and dual-15" 4-figure models, and using two for 11.2 is life changing (4 woofers). I would say that a good 10" will work for office or bedroom size areas, while 12" is better for living room/family room/basement, and personally I think 15" are useful in an infinitesimally small percentage of setups as you are then needing the speakers to handle ALL mid-bass and you lose the omnidirectional (ideal) bass. Pioneer would be a good choice, Polk if on sale for $100 or so but just like Klipsch they're a low-mid level brand that markets itself as upscale and charges a premium for speakers that aren't special in any way; Polk have a very, well, "speaker-y" sound, it's not natural or enveloping, and they're poor surround choices, while Klipsch all sound identical until you get into the four figure a piece stuff, and while a bit warmer and laid back (less fatiguing) than Polk, they're still very sterile and, well, despite the cheaper cabinet material, the Klipsch Icon series is a worse sounding setup than the Pioneers which are 1/6-1/12th the price, and while Klipsch spent money on exotic wood enclosures and Jones went with MDF, the Klipsch drivers and crossover would be worth about $40 sold together outside of a cabinet but without any manufacturer name, and the Pioneer crossover alone is worth over $100 if you compare it to what's available commercially. In fact, the individual parts add up to nearly $300 for the Pioneer, vs $40 for the Klipsch, but you get two Pioneer 4-driver towers for 150 or one 3-driver tower from Klipschffor$800-1300! Polk drivers, well, they just add enough mids or woofers to fill up the front of the cabinet, but the quality is at the $25/driver level at the very most and their x-over is maybe worth $15. Their tweeters are very good though, probably worth around 40-50 a pop.
Oh, my Primary subwoofers are a mix and includes B&W DB1, Paradigm subs, HK subs, Pioneer, JBL, and I would say that the 12" drivers in my Cerwin Vega VE12's count (CV have a bad rep amongst the stuffy douchy audiophile crowd, but I've measured performance that far exceeds the price, they're also easy to drive loud without any distortion, there is no noise even pushing 102dB (-130dB THD), and they're fun as hell!
Oh, I got off track. Point is that I can maybe do some dB levels of fans, I am usually too busy to video them all (and unlike music or film, they don't sound the same recorded as in person).