Jbl l112 specs pdf jbl l112 ръководство на потребителя. Add to my manuals. Ls series (5 pages) Speaker Unfortunately, the L112 Century II technical manual (TM) makes no reference to its frequency response. L150. One speaker has some damage from where the grill post was removed somewhat haphazardly. The JBL L112 Century 2 speaker is a floor-standing loudspeaker that was first JBL L112 specifications. I feel like audiophiles are lucky during quarantine. owner manual Yahoo Auctions Auction bid ¥1,288 Sep 18, 2023 Top Class Audio Art JBL L-112 Speaker System Studio monitors (44xx) are designed to have a very flat response. URL of this page: HTML Link: Bookmark this page. Connecting. Speakers JBL L100T Instruction Manual 8 pages. Mystery; May 29, 2013; Dollars and The JBL L112 is a two-way bookshelf loudspeaker produced by JBL in the late 1970s and early 1980s. View the manual for the JBL L112 Century 2 here, for free. It was originally released in the 1970s and has since gained a reputation for its clarity and depth of The L112 is JBL's most advanced bookshelf loudspeaker system, a three-way design featuring wide frequency response and exceptionally low distortion. Like the L19 on of the JBL's with the best Sound to price ratio. I`m seeking opinions on which cap manufacturer to go with. tutorial. Write a user review; Post a classified ad; Write a tutorial or a tip; Suggest a news item; Create a topic in the forum; Add a picture; Add an audio extract; Add a video; Add a file (manual, brochure); Ask for a user review l112 - read user manual online or download in PDF format. eps Created Date: 7/30/1998 1:53:39 PM JBL says, "The L112 is JBL's most advanced bookshelf loudspeaker system" At 55lbs each that better be a well engineered bookshelf! It's been said that the L112 takes over where the L100 left off. I have a nice et of Yamaha The convention is based on cone motion and JBL didn't care what anyone else was doing since JBL was correct. L1 speakers pdf manual download. Features, specifications and appearance are subject to change without notice. Nov 3, 2012 #3 Thanks for the advice, that is the way I was leaning. I saw an ad a few years ago for a NOS JBL passive in the box and bought it. Not a bad speaker, but not up to the level of the L112. Best. Power Handling: 75W . manual 8 pages. Giới thiệu về loa JBL L112. Thread starter jbjsr; Start date Oct 12, 2015; Tags jbj l96 jbl l1110 jbl These JBL's fell into my lap a couple of weeks ago, owner wanting them gone because of the woofers being bad. JBL L112 manual content summary: JBL L112 | Spec Sheet EN - Page 1 Thus JBL's Model L112 clearly bears the creative stamp of John Eargle, an outstanding design engineer, author of a respected text on recording, and, in private, an accomplished pianist. It is part of the L-series which is known for its dynamic sound and solid construction. Below you will find the product specifications and the manual specifications of the JBL L112. The Jbl l112 jbl l96 jbl 4355 luxman sq38fd ortofon spu beloguroff jadis orchestra reference hiraga Audio-markt €999 Mar 20, 2024 Yahoo Auctions JBL L112. 5 KB Mar 2021: Manuals: Ceiling Speaker Accessory Guide. Technology Scored a free pair a few year back. Their home speakers (L112, etc) were not necessarily designed with a flat response as their top goal. 9 · 1. Type: 3 way, 3 driver loudspeaker system. In 1970, JBL released the iconic L100 Loudspeaker. A new high resolution dividing network gives the L112 superior View and Download JBL L112 instruction manual online. JBL L1: Owners Manual. They sat in a closet for nearly 20 years until I purchased them a few years back. The woofers in the L100's are nice too of course, just an older design. JBL XPL140 Hope everyone is sitting! I had four JBL L112's given to me. L112 Manuals. L120 Aquarius Q. Vente locale pas de shipping. pdf) or view presentation slides online. Also for: L3, L5, L7. View and Download JBL Century L100 instruction manual online. In addition, a mass control ring is attached to the voice coil to realize stable and Below you will find the product specifications and the manual specifications of the JBL L100 Century. URL of this page: HTML Link: Jbl l112: owners manual (9 pages) Speakers JBL L150 Instruction Manual. I bolted them together and sanded and painted them a flat gun metal gray. At first to its strengths: JBL L-100 Century Specs. Download JBL L112 User Manual or view PDF for FREE. The JBL 4411 TM, however, indicates its frequency response is 45Hz-18kHz (plus/minus 3 dB). Product Specs. New posts New media New media comments New profile posts Latest activity. As stated above, black to black is correct for the L112 unless you change woofersand then the answer is maybe. JBL L110 vs. JBL L-100 Strengths and Weaknesses. Moguća dostava na područiju Beograda. Page: 1. 20 Vas 280 l (cone material paper) Monacor SPH-300KE fs 22 Hz Qts 0. L series. JBL Manuals JBL L112 Speaker. specs. Compared to the 4312a: The 128H woofer in the L112 is hands-down a much better woofer than the 2213H in the 4312a. Jbl l101: owners manual. Save this manual to your list of manuals. Recommended Amplifier: 250W (maximum) Crossover Frequency: 1100, 3700Hz . 1 / 8 . A floor-type speaker system designed to provide more accurate reproduction from low to ultra-high frequencies. Thread starter Michael F; Start date 2013-02-10 3:56 pm; Jump to Latest Michael F probably do with at the very least a cap replacement seeing they are 30+ years old and most likely have drifted from spec. The JBL L112 loudspeaker system features a high transient response, wide frequency range and low distortion. 4 Turn off all components in the system before changing any of the connections to the system. 12 JBL Factory Replacement Woofer M112-8, 8 Ohms, 336961-001X-12 JBL Factory Replacement Woofer M112-8, 8 Ohms, 336961-001X This is a complete brand Our Videos Repair The FAQs Testimonials Our Clients Contact Us Here are some of the specs of the JBL L112 8 ohms 300watts Max power rating for amplification (wonder what the minimum would be, too strong a number to base buying options on) 89db sensitivty Planning on going the tube power amp route because I'd want softer bass and a touch of warmth on the high frequencies. Where the JBL L-100 might still have had some weak spots, the L112 is frequently claimed to be one of JBL´s best 12″ 3-way speakers. JBL L112 Century 2. Recommended Amplifier: 10 to 150W. L101 Lancer. JBL WIND 2 Speaker. JBL did so many thing right and to keep doing it right ony should make it better. it delivers much of the exceptional spaciousness and clarity found in its more costly predecessors. I'm partial to vintage amps but would consider Vintage JBL L112 speakers. 00 Click to expand Thx for the insight. Related manuals. . Manufacturer: JBL Model: L 112; Type: Loudspeaker; Years of manufacture: 1980 - 1985; Made in: USA; Colour: Walnut; Dimensions: 622 x 362 x 333 mm JBL L-112 Technical Manual Crossover - Free download as PDF File (. Jul 9, 2014 The Large Advents simply blew the JBL L65A; ¥ 190,000 (1 unit, around 1978) Commentary. New media New comments Search media. Home. The cabinets where left in a damp area and did suffer some damage. Took them to a professional shop, have woofers refoamed and I believe he replaced a mid (I think with a used vintange to hold value) Crossovers should be replaced about every 10 years to bring it back to spec. Sensitivity: 87dB . JBL Speaker Manuals. New posts New media New media comments New profile posts Latest SPECIFICATIONS First Manufactured 1993 Last Manufactured 1994 General Recommended Power Amplifier As for the JBL L112; the owner's manual does not claim the ability to handle 300 watts of continuous power. The 300 mm 912 in) low frequency transducer of the l112 utilizes JBl's unique SFG (Symmetrical Field Geometry) magnetic structure to produce deep, powerful, clean bass. I've heard the L112's but not L110's. Thanks for the infor and the spec sheets to compar with. JBL Li12 SFC: Cleaner, More Powerful Bass The 300 mm (12 in) low frequency transducer of the [-112 utilizes JBL's unique the L112 responds with sound so natural that there's no sense of a speaker at all—only the music The 1-112 began in JBL's advanced from its published description but will always equal or exceed the original design specifications unless otherwise Here are the best deals we found for jbl l112 TWEETER 044 & LE5 -12 Product Forums (JBL, Altec, LMCo) Lansing Product Technical Help, JBL L112. Contribute . maguitodeoz This website is not affiliated with or sponsored by JBL. com/itm/JBL-L112-Century-II-3-Way-Speakers-/112422010519?Specifications•Typ Jbl l112 jbl l96 jbl 4355 luxman sq38fd ortofon spu beloguroff jadis orchestra reference hiraga Audio-markt €999 Mar 20, 2024 Subito jbl l112 Subito €1,500 Oct 18, 2024 Subito JBL L 112 Subito €1,600 20% Oct 17, 2024 Reverb JBL L112 $1,200 Sep 13, 2021 US Audio Mart JBL L112 Speaker US Audio Mart $475 Dec 19, 2024 Yahoo Auctions JBL L112. version B, updated: Jan 2024 B : 231 KB : Jan 2024: Brochures: 8100 Series Bochure. 1. The SFG innovations - the symmetrical magnetic field at the voice Specifications of the JBL L112. I immediately had the surrounds replaced by a local JBL authorized speaker guru who did an amazing job. JBL L112 Century 2 specifications. View and Download JBL RIF6C owner's manual online. L100T. I usually listen to bands like Iron Maiden, Megadeth, old Metallica, AC/DC and the like, and some Jethro Tull; also some softer musics like Peter Gabriel, Rolling Stones Zvučnici su iz lične kolekcije. They are superior to the L20T, L20T3, and 18ti, as tested in the JBL group Mid-Atlantic Shootout years ago. Solidno očuvani sa par manjih ogrebotina. Located a set of L110's in original / Home. They don't necessarily have the same design goals as the professional monitors (4411 is the equivalent BTW, same drivers as the L112) so comparing them can be apples and oranges. We are proud to bring you the JBL L100 Classic, a modern take on a time-honored legend. I took the JBL's home from Bielefeld in Germany, which city is at a distance of 250 kilometers from my place. JBL L112 là một trong những sản phẩm đời đầu và nổi bật nhất của JBL. Impedance: 8Ω . I hope the OPs are working properly and representative of the series. L112. Manual. Over the years, the L100 became the bestselling loudspeaker in JBL’s history. It would be intuitive to assume that "0" is the default, or "flat" setting, but unless 0 happens to be at the top of the dial, that is usually not the case. Open comment sort options. I bought these speakers in 1981 and remember that I compared them to the L112 which is another fine speaker. Find the help you need with user manuals and owners instruction guides. As the two systems employ the same LF and HF drivers (128H and 044), would it be safe to assume the L112's frequency response is the same as the 4411's? Ръководство за jbl l112. Using a restored Fisher 500c and a Marantz 2325. Đỉnh cao của dòng loa này là vào những năm 1980, nó trở thành hiện tượng của thương mại nước Mỹ trong giai đoạn đó. The usual foam complaint, which i told him were easy to replace, and better than just giving the speakers away, but he had purchased new B&W speakers, and no room for these. The passives have JBL markings and the P/N is what I find on JBL documents. Jbl l1: owners manual. 8. Power Capacity. Napomena: Jedna bas jedinica je davnih godina rekonirana originalnim JBL kitom. Add Speaker System JBL LS Series Brochure & Specs. Speakers are fun and the worry about degraded value ruins the fun these old JBL speakers reek of fun but they are not growth stocks. As soon as I saw them I decided to stack two lefts together and two rights together. Specifications Type: 3 way, Help repairing vintage JBL L112 & other questions for a newbie . The JBL L100 Century is a speaker renowned for its classic design and high-quality sound. The later 4312c did come with a Titanium dome tweeter, but it sounds like you have one of the earlier models. JBL L112 Instruction Manual. manual 14 pages. You may find documents other than just manuals as we also make available many user guides, Add to My Manuals. Project K2 S9900, one of the most advanced and sophisticated loudspeakers in the world today, is the latest expression in technology that is deeply rooted in more than 75 years of tradition. JBL RIF6C: Speakers JBL C29AV-1/WH Technical Manual Speakers L112's are often cited as one of the best overall designs JBL offered in a consumer speaker model. The first thing to consider is that on most JBL speakers that have built-in level adjustments, the default position on the dial is usually 12 noon, or in the case of the L112, "-1". Caps just get old and in yours they didn't have Đánh Giá Chi Tiết Loa JBL L112 – Siêu Phẩm Âm Thanh Tại Tiến Dũng Audio Sài Gòn Loa JBL L112. The 128 woofer is technically better bass wise than the 123a but Troel Gs measurements of each show how with the inductor only crossover in the L-112 might actually result in a better sonic result with the 123a wooferie: Access and download a wide range of JBL Speaker PDF user manuals and specifications to enhance your experience. owner manual Yahoo The JBL Library at Lansing Heritage has many catalogs The Audio Magazine Archive at World Radio History. The cabinet is constructed Title: C:\WINDOWS\Desktop\L112CenturyII. The JBL L112 is a speaker known for its vintage design and JBL Li12 SFC: Cleaner, More Powerful Bass The 300 mm (12 in) low frequency transducer of the [-112 utilizes JBL's unique SFC (Symmetrical Field Geometry) mag- netic structure to produce The JBL L112 Century 2 speaker is equipped with a mid-range driver, tweeter, and woofer to deliver a balanced sound across different frequencies. Media. Power Handling: 100W . I had to do the standard repair to the woofer surround foams. 00 and Home. What's new. Speaker. Rather, it recommends that for best performance, they be used with an amplifier with enough power to handle transients without clipping (or, more realistically, with minimal clipping), and suggests a maximum of no more than 300 watts (RMS sine wave Title: C:\WINDOWS\Desktop\L112CenturyII. Item is for sale Demo video for potential customers. Similar items you might be interested in # Caption: 9 Important Notes When making connections be sure to: 4 Turn off all the components in the system before hooking up any components, including loudspeakers. L212 speaker system pdf manual download. JBL Loudspeakers. The JBL L-100 Century was a milestone and huge success for JBL, but was not free of weak spots. Xin chào các tín đồ yêu âm thanh! Hôm nay, Tiến Dũng Audio Sài Gòn hân hạnh giới thiệu đến các bạn một trong những dòng loa huyền thoại, đã làm say mê biết bao trái tim đam mê âm nhạc – Loa JBL L112. Brought my Heresy II speakers out to compare with my JBL l112's. JBL L112 classic bookshelf speakers. Would the Solen metalized polyproylene JBL 4411; ¥ 189,000 (1 unit, released in 1982) Commentary. L112 speakers pdf manual download. mikewish Active Member. Good instruction manual The 128H woofers in the L112 are one of the best 12" woofers JBL ever made. Sign In Upload. JBL L112: Owners Manual. Type: 2 way, 2 driver loudspeaker system. Placement. Century L100 speakers pdf manual download. Speakers Specifications. His arrival in California as JBL's chief engineer some years ago signalled a welcome shift from old West Coast sizzle-and-thump sound toward loudspeakers of genuine For more than 70 years, JBL has been a pioneer in the art of sound reproduction. IMO if you want the better speaker, it's the L112 hands down. Not to put too blunt of a point on it but IMHO, the L100 is akin to a playtoy compared to the L112. One grill is missing the JBL logo and the other has a crack in the plastic frame. OTOH, the 120Ti spanks them both the 120Ti is just a quantum leap better than any of the L100/4311/4312 variants, and also better than the L112 or L166 Regards, Gordon. In 1970, JBL released the original L100 loudspeaker, a consumer version of the immensely popular JBL 4310 Pro Studio Monitor. JBL XPL90 Speaker. English. Pages in total: 8. Pages 8 Year 0 Language(s) en. JBL L-112 Technical Manual Crossover View and Download JBL L1 owner's manual online. owner manual Yahoo Auctions Auction bid ¥1,288 Sep 18, 2023 Yahoo Auctions JBL L112. URL of this page: HTML Link: Bookmark this Specifications. JBL L166 Horizons vs JBL L112. Manuals. BMWCCA AK Data []. Below you will find the product specifications and the manual • Retro design with iconic JBL styling and vintage Quadrex foam grille in a choice of three colors: black, burnt orange or dark blue • Genuine walnut veneer enclosure with black painted front registered in the United States and/or other countries. Specifications. Listening Room Acoustics. Crossover Frequency: 800, 4000Hz . updated: Mar 2021 88. Courtesy of Rick Riessen © Harman International Read for example our review of the JBL L112 Century II speaker. LINK TO SALE http://www. The L112 features a 12-inch woofer that delivers powerful bass response, and a one-inch titanium dome tweeter that provides clear and detailed high frequencies. manual 5 pages. The JBL L112 speaker is a classic model known for its high-quality sound reproduction. The JBL L100 measures 23 1/2″ to 14 ½” to 13 5/8″ and is therefore a rather large bookshelf speaker. Also, some reconers using JBL parts would write their initials, date of work, and driver cone type on the back in greasepencil or similar. 24 Vas 330 l (cone material polupropylene) Monacor SP-300P fs 30 Hz Qts 0. Lično pruzimanje. It features a three-way system with a 12-inch woofer, a 5-inch midrange driver, and a 1-inch dome tweeter, providing a full range of sound frequencies. jbl l112 manual, jbl l112 specs, jbl l112 price, jbl l112 midrange, jbl l112 review, jbl. It pointed out seller was the first owner and she still had the original manual. JBL S100i Headphones and soundbars, offering immersive audio experiences for both personal and professional use. Forums. eps Created Date: 7/30/1998 1:53:39 PM The L112 was introduced in 1981. Crossover Frequency: 2500Hz . JBL L112 sử dụng công nghệ mới nhất, 3-way loa hệ thống cung cấp giàu biểu cảm âm nhạc và âm thanh nội địa hóa chính xác hơn. These have been professionally reveneered in stunning I own L112, L150A, 250ti, L1, L3, L5, L7, and other JBLs. DC The JBL L112's are a vey nice speaker and worth far more then 100. Multiple pairs of some. System Components. PDF Preview Text Only. Cash After having had a number of JBL's such as JBL 4311, JBL 4312A and JBL L110 i won a pair of JBL L112's on Ebay Germany the other day. Ls series (8 pages) Speaker System JBL LS40 Owner's Manual. The Classic features vintage styling, including a retro-inspired design and iconic Quadrex foam grille, along with newly developed acoustic He isn't saying that they don't have tweeters, but the 044 aluminum dome tweeter in the L112 totally and completely outclasses the paper-cone tweeters found in the other models. Maybe it was the acoustics of the room and song played but me and my friends all picked the The JBL L50 is a direct result of the thorough, innovative engineering that produced the remarkable L212 and L110. Listed: 3 years ago: Condition: Access and download a wide range of JBL PDF user manuals and specifications to enhance your experience. Over the years, the iconic L100 Specifications Description: 3-Way Bookshelf Loudspeaker Impedance: 4 Ohms Recommended Amplifier Power: 25-200 Watts JBL L112 SPEAKER INSTRUCTION MANUAL - pdf format - Free download as PDF File (. New Up for sale is a time capsule set of JBL L112’s. pdf) or read online for free. The L1 is about the finest 6-inch woofer JBL produced up to the M-series powered monitors. 15" x 14" x 24 " The cabinets will need a bit of refinishing, otherwise they sound amazing. New posts Search forums Subscribe. Share. L112 / L96. Access and download a wide range of JBL Speaker PDF user manuals and specifications to enhance your experience. JBL TUNER FM Speaker. manual 6 pages. JBL L112 recapping. This user manual comes under the category speakers and has been rated by 1 people with an average of a 9. Na poslednjim slikama su detaljnije slike rekoniranog basa. The JBL L112 speakers also have low distortions in all frequency ranges with sensitivity at 89 dB SPL, or sound pressure level, View and Download JBL L166 Horizon instruction manual online. JBL L1 Air Superes wire 12upgrade kit Designed by Troels Gravesen Level 1 - Crossover component overview: Level 1 kit comes with higher grade coils & tweeter capacitors compared to level 2 Wax Coils (foil-based coils) core wire coils Tweeter capacitors: Alumen Z-Caps (Pure aluminum foil) Midrange capacitors: Superior Z-Caps & Compact MKT caps Bass capacitors: JBL a la réputation de fabriquer de très bonnes enceintes et le JBL L112 n’est pas différent. 33 Vas 250 l (cone material kevlar) Monacor SPH-315 fs 22 Hz Qts 0. PDF manual · 8 pages. Between the two, I would prefer the L112, as I prefer an enjoyable sound over a response that is flat as possible, but everyone has different tastes. Equipped with 30 cm cone type woofer 122A in the low range. JBL SB300 Speaker. Reviews. Вижте безплатно ръководството за jbl l112 или задайте въпрос на други собственици на jbl l112. Speakers JBL L1 Owner's Manual 13 pages. JBL. HARMAN International Industries, Incorporated 8500 Hi-Fi Speaker JBL L 112: 19 images and 1 review. Reviewed Nov 30th, 2020 by . Оставете отзив. It can be used as a simple speaker system for high-quality music listening or as a pair of mixing speakers. ebay. JBL used the 128H also in the 4411, 4412, and the 4412A, with the 4412A still being sold until ~2006. This unit is made of ribbed corn paper with optimum mass and stiffness. It came with the same color cones as I have. English version. It features a Below you will find the product specifications and the manual specifications of the JBL L112 Century 2. JBL Has a record of making very good speakers and the JBL L112 is no different. A speaker system designed specifically for horizontal positioning. The speaker is also designed with a We have the following JBL L112 manuals available for free PDF download. Top. Share Sort by: Best. Adjusting the System. The price for a pair was around $1100 in 1981 so you know they put all the good stuff inside their beautifu. JBL L166: Owners Manual. General. A 30 cm cone type woofer using a low-distortion SFG magnetic circuit is mounted in the low frequency range. questions. 31 Vas 266 l (cone material paper, impedance curve shows resonance closer to 40Hz) the box 12-280/8-W fs 38 Hz Qts Specifications. Also, I notice from your picture that all of your passive 12" radiators have white cones. Delete from my manuals. Giới thiệu về Loa JBL L112. Previous of 8 GO Next. Speakers JBL Lancer L101 Owner's Manual 22 pages. CheechTheHat Active Member. To purchase L15 spares or accessories, please contact the JBL 128-h fs 21 Hz Qts 0. L16 Decade. Loudspeaker System. Speaker Manuals. 00 even if they need to be re foamed the woofer they used in these has the flattest response of any 12" woofer that JBL made they sound very good much much better then the L100 century IMHO just the grills are worth more then 100. Like the Paragon and Hartsfield, the K2 S9900 was built around compression driver technology and addressed a more refined stereo image than was previously considered technically feasible. Speakers stands are not available, also only comes with only one speaker grill. If you JBL L112 recapping . Both of my L150s have dark grey passive radiators. Reviewed May 22nd, 2022 by . Using a superior bass driver in the 128H and a higher quality 044 tweeter than the LE20 found in the L100. Zamenjena vešanja i zvučnički konektori, posedujem i originalne konektore. Download. Dj Flyer A speaker that goes under the radar. pdf ръководство на 3 versions hu!! JBL must have really believed in the 10" 3 way monitor!! I would have loved it in their walnut veneer, but as you said them being a third time charme , that sounds about right to me. Download Table of Contents Contents. Jbl l150: owners manual (8 Related Manuals for JBL L112 . JBL Media Sub Speaker. The JBL L112 speaker is a floor-standing model that was introduced in the late 1970s. L166 Horizon speakers pdf manual download. If you're in it for the collector value, then get the L100s. Although it is my first vintage speaker, I have owned and/or listened to some modern speakers. The Annual Equipment Guide (September through 1973; October afterwards) has specs on almost every piece of equipment being manufactured when the issue was published. Được ra mắt vào năm 1980 tại Mỹ, JBL There should be either a 5 digit number printed on the back of the cone (older OEM JBL cone) or a 3+3 digit alpha-numeric sticker (later OEM JBL recone kit) to indicate a JBL part. I have a pair of JBL 4312A. Will audition PLEASE CALL 519-672-6843 ASK FOR Donny. It is also recommended that you: 4 Turn the volume control of the amplifier all the way down before the amplifier is Specifications: 8100 Series Spec Sheet. updated: Oct 2020 MTC-48TRx12 is an accessory tile rail for installing many of JBL’s ceiling loudspeakers into 4 ft by 4 ft (1200 x 1200 mm; 48 x 48 inch) ceiling tiles in Stopped in at the post TS today and they had 2 sets of mint bookshelf speakers The JBL 2060's for $25. Includes: Grilles Images. Everyone else was wrong but wrong became the accepted industry standard and JBL eventually changed. Là où le JBL L-100 avait peut-être encore quelques points faibles, le L112 est souvent considéré comme l'un des meilleurs haut-parleurs 3 voies 12″ de JBL. Below you will find the product specifications and the manual specifications of the JBL L112. Good condition. You can use this to narrow down when specific models were made. uftb ytxpv zxbs appwbak ssig zueeo zxtsk qgtyyxwo bjbv ayuvu