
It may not be the sexiest part of your rig, but the speaker enclosure plays a crucial role in the signal chain. Here’s what’s going on inside.
In our mad pursuit of boutique gear, it’s easy to overlook the humble speaker cabinet. While we drill down on the merits and specs of various speakers, the box that houses them typically takes a backseat to everything else in our signal chain. Which ain’t right, if you think about it. No guitarist is going to wow the crowd dangling a raw 12" speaker from a pole, right? The truth is, your cab plays as important a role as any other device in your rig, so it’s worth taking the time to explore it in its various forms. We’ll cover key points that will better acquaint you with what you already own and help you make an informed decision the next time you purchase a combo amp or extension cab. And while we’re at it, perhaps we’ll dispel a few myths.
Cabinet Material
If you ask guitarists what their cabs are made of, most will say “wood.” That’s the short answer, but it’s also very broad and incomplete. There are many different types of wood, and what a builder chooses will affect how the cabinet performs. Each type of wood has its pros and cons, and whether a cab has an open or closed back has a huge bearing on what a builder chooses to construct it with.
Many combo enclosures are made from solid wood—particularly vintage Fenders, which were built with solid pine. And since vintage gear is the gauge by which most new gear is measured, replica pine cabinets have grown in popularity over the years. Solid pine cabs typically have an open back, meaning the speaker is exposed to the air and thus delivers a more diffused and less directional sound. Solid pine is lighter than other cabinet woods and, as anyone who has lifted a combo amp knows, weight savings can be crucial—especially if you haul your gear to lots of rehearsals and gigs. But pine flexes, and this can emphasize certain frequencies. Because open-back combos don’t trap soundwaves, but rather allow them to escape, you don’t end up with resonant frequencies being accentuated by the cabinet walls. This explains why solid pine is ideal for open-back combos. Closed-back cabinets are more focused and directional, so it’s rare to find one made of solid pine, due to the aforementioned flexing and the sonic chaos it can bring.
Whether a cab has an open or closed back has a huge bearing on what a builder chooses to construct it with.
Most closed-back, or sealed, cabinets are constructed from plywood, as are some combos. The industry standard is 18 mm Baltic birch plywood, which differs from the sheets of plywood sold at the hardware store. To be a useful cabinet material, plywood needs to be voidless—meaning there is no trapped air between the plies. Unlike plywood used for less demanding tasks, Baltic birch plywood is made to be voidless, and this prevents the cabinet walls from rattling when you play. In Baltic birch plywood, each ply is a uniform thickness, laid with the grain alternating between north-south and east-west, and the boards are laminated with exterior-grade adhesives. The rigidity of Baltic birch plywood makes it an excellent material for closed-back cabinets, such as 4x12s and bigger 2x12s. Because of how it’s made, Baltic birch is nearly indestructible. However, this also makes it very heavy, which is why you see wheels on a lot of these larger cabinets.
You’d think the strength of Baltic birch would make it a good material for bass cabinets. Well, bass cabinets tend to need more rigidity than even Baltic birch offers, so they’re often made with chipboard or medium-density fiberboard (MDF). Both of these materials are extremely strong and have little-to-no flex because of the way they are made. Chipboard, sometimes called particleboard, is made by gluing together many different chips of otherwise useless wood scraps—and sometimes even sawdust. The chips are bound together with a resin and then drawn out into boards. MDF is made in much the same way, but, as its name suggests, uses much more finely broken-down wood fibers. This material is then pressed together with wax and resin at high temperatures. While the strength of these engineered materials is very high, so is the weight.
As a general rule, to do justice to the low frequencies of bass, mass wins. You need all that physical weight to help produce a burly low end. But there’s a downside to these man-made materials: They can deteriorate over time with heavy use, such as banging the cabinet against every stair as you hoist it up three flights to play for those 10 people.
Many combos have medium-density fiberboard cabs, which are sturdy but heavy. Some players opt to re-house their combos in aftermarket enclosures made of solid pine—the wood Leo Fender originally used. Available for popular models like this Fender Blues Junior, pine cabs look cool, shave pounds off the combo’s total weight, and arguably enhance the amp’s tone.
Photo by Andy Ellis
Cabinet Joinery
I’m sure you’ve heard a lot about different types of corner joints and how the joinery method impacts the cabinet. There are three main types of joints: the rabbet joint, the box or finger joint, and the dovetail joint.
The three types of joinery used for building speaker cabs. Dovetail joints are the strongest and are most often found on high-end cabinets with exposed, stained wood.
Diagram by C.J. Sutton
As you can see in the diagram, these are quite different from each other, but it’s important to note that unless the joint is made poorly and allows the corners to flex, the joinery type has virtually no effect on the sound. Rabbet joints are the most commonly used in domestic cabinets because they are fast and easy to execute, and they’re strong. Finger joints are the most sought-after because that’s how Leo did it in the ’50s and ’60s. These joints are stronger than rabbet joints and reduce the potential for flexing. The strongest of all is the dovetail joint. Good dovetail joints can hold together without any glue, but don’t worry—no one actually builds speaker cabinets with unglued dovetail joints. You’ll see dovetail joints on higher-end cabinets, particularly those made of stained wood with visible joints that are part of the look.
The Baffle
The front part of the cabinet where the speakers mount is called the baffle. It needs to be the strongest and most rigid piece of all because this part of the cabinet is subject to the most impact stress. Baffles are nearly always made with Baltic birch plywood, or in some cases even MDF—even if the cabinet walls are made of solid wood, such as pine.
There’s a lot of hubbub about whether speakers should be mounted to the front or rear of the baffle. When a cab has a front-loaded speaker, the grille is removable to allow access to it. Front-loaded speakers are found most often in bass cabs and ported guitar cabs, where the back of the cab is designed for rigidity and is not removable. A rear-loaded speaker attaches to the back of the baffle, which you access in closed-back cabs—such as a Marshall 4x12—via a removable back panel. Most open-back combo amps also sport rear-loaded speakers.
The rigidity of Baltic birch plywood makes it an excellent material for closed-back cabinets, such as 4x12s and bigger 2x12s.
The theory behind front-loaded speakers is that they don’t seal up perfectly to the baffle and thus allow air to escape, which adds some musicality to the sound. Also, in a recording situation, it’s easier to swap out front-loaded speakers in a quest for different tones. Conversely, rear-loaded speakers can be more of a pain to replace. In closed-back cabs, you have to remove the entire rear panel. If you’ve ever opened up a 4x12 cabinet, you know there are a lot of screws involved in securing that back panel. And if you’ve ever decided to take a shortcut and not put all the screws back in, then you know about the potential for ugly rattling.
A side note about 4x12 cabs: Some have posts inside that connect the center of the baffle to the rear panel. These baffle posts are designed to offer additional support and create one more connection point to keep the rear panel from flexing.
Speakers can be attached to either the front or rear of the baffle. Front-loaded speakers are accessed through a removeable grille; rear-loaded speakers are housed in open-back enclosures or in closed-back cabs with a removeable rear panel.
Diagram by C.J. Sutton
Before you can access the rear-loaded speaker in some open-back combo amps, you first have to remove the chassis. This means virtually disassembling the entire amp. Please note: Never stick your hand inside an amp chassis. There can be lethal voltages present even after the amp is turned off and unplugged.
So is one speaker-mounting method superior to the other? That depends on what you’re after: Rear-loaded speakers form a tighter seal to the baffle and provide a sound that works well with rock ’n’ roll and heavier music, and front-loaded speakers can sound airier. But there’s no right or wrong. My friend Jason Jordan of Monarch Cabs says it best: “It’s all a matter of preference, really. What guitarists think of as a “good” sound is based on the music they listen to. As builders, we have formulas for making speaker cabs sound a certain way. It is a science. But at the end of the day, you need to experiment and listen, and then simply go with what works for you and your playing.”
Although the vast majority of amp cabs have either an open back or closed back, it is possible to have both. This 4x10 Marshall cab has been professionally modified to be configured either way, depending on the size of the stage and the band’s music. If you’re considering doing this yourself, the trick is to cut the back panel into thirds and then completely wrap each piece in “cab carpet.” This creates a super-tight fit between the panels and prevents rattling. In closed-back mode, tour-case latches hold the middle section securely to the fixed top and bottom pieces.
Photo by Andy Ellis
Cab Placement
So what happens when you want to take your rig public? What should you consider when placing an amp or cab onstage? The answer depends greatly on whether the cab is going to be miked up or not. If it is, then the cab can really go anywhere. To keep the stage volume down, many bands face their cabs backward—or even remove them completely from the stage—because the miked sound will be fed back through the monitors, which can be either onstage wedges or in-ear buds.
If you’re not miking your speakers, and the sound from the cabinet is the sound the audience will hear, it gets a bit trickier. You have to position the amp so you can hear it while you’re playing, yet the audience also gets a good mix. If your cabinet has wheels, you might find that popping them off or setting the cab on its side increases low-end resonance through greater contact with the floor. But this stage coupling might introduce muddiness into the band’s sound—exactly what you want to avoid. It depends on the stage and room, and each venue is different. The way to tame unwanted rumble is to reduce contact with the floor, perhaps by using an amp stand, or keeping the wheels attached to your cab, or placing it on the rolling bottom of a road case. Wheels offer another advantage: They make it easier to move your cab around during soundcheck until you find the sweet spot where you, the band, and the listeners can all enjoy your cosmic licks.
Some amp cabs are designed not to be heard—at least by anyone in the immediate vicinity. Such sealed “speaker coffins” have an internal mic clamped to a gooseneck to allow for precise positioning. Accessed through a hinged trap door, the mic connects to a recording console or front-of-house mixer via an external XLR jack. Notice how the Celestion Greenback in this Demeter Silent Speaker Chamber is front-loaded to facilitate quick speaker swaps.
Photo by Andy Ellis
Visual Vibe
Some players swear the cab’s covering material—or even its color—and grille cloth have an effect on tone. In my experience, I haven’t noticed any evidence of this. Certain grille cloth materials, such as cane, are more rigid than others, and this could potentially influence the sound, but essentially grille cloth choice is cosmetic and if it has any effect at all on tone, it’s very slight. By the time the drums get pounding and you’ve cranked up your amp in response, it’s the speakers you’ll be hearing, not the grille cloth. And if you think a cab wrapped in red or green vinyl sounds better than black Tolex, who’s going to dispute that? After all, you might actually play better because you love the way your amp looks.
By the time the drums get pounding and you’ve cranked up your amp in response, it’s the speakers you’ll be hearing, not the grille cloth.
While some players agonize over the thickness of the grille cloth or cabinet covering material, there’s little evidence these cosmetic details have any significant effect on tone.
Photo by Michael Silva
Eyes On the Prize
When it comes to gear, my motto has long been “if it sounds right, it is right.” Once you understand the basics—wood, construction details, and how speakers are mounted—it’s then a matter of putting in the hours with different types of rigs and amp cabs.
In the process, you’ll develop an instinct for what sounds best with your guitars, technique, and musical style. And this is where the fun begins. My advice? Don’t stress over little things like what type of corner joints you have. Just get out there and play!
If you’re not miking your speakers, and the sound from the cabinet is the sound the audience will hear, it gets a bit trickier. You have to position the amp so you can hear it while you’re playing, yet the audience also gets a good mix. If your cabinet has wheels, you might find that popping them off or setting the cab on its side increases low-end resonance through greater contact with the floor. But this stage coupling might introduce muddiness into the band’s sound—exactly what you want to avoid. It depends on the stage and room, and each venue is different. The way to tame unwanted rumble is to reduce contact with the floor, perhaps by using an amp stand, or keeping the wheels attached to your cab, or placing it on the rolling bottom of a road case. Wheels offer another advantage: They make it easier to move your cab around during soundcheck until you find the sweet spot where you, the band, and the listeners can all enjoy your cosmic licks.
For two decades, Clapton's Choice Signature Strings have delivered the legendary tone Eric Clapton relies on every time he picks up an acoustic guitar. To celebrate this milestone, Martin Guitar is introducing limited-edition 20th anniversary packaging for these fan-favorite strings--available now through March 2026.
Every limited-edition pack also gives players a chance to win a Martin 000-EC 30th Anniversary guitar--a beautifully crafted instrument with a retail value of $4,999, inspired by the Martin guitars Eric played during his legendary MTV Unplugged performance. The guitar will be awarded to one lucky winner who finds a special ticket inside a pack of strings.
Fans can also enter a second-chance giveaway online for more opportunities to win exclusive prizes, including a Martin guitar strap, poster, collectible lanyard with three custom patches, or even a year's supply of strings.This contest is open to U.S. residents only and ends March 31, 2026. No purchase necessary.
Enter now and learn more at martinguitar.com/eric-clapton-giveaway.
The anniversary release also coincides with the upcoming arrival of Unplugged: Enhanced Edition on vinyl and CD, available May 9. The iconic installment of the MTV Unplugged series--and the greatest-selling live album of all time--returns over 30 years later in an all-new extended, remixed, and remastered version. Featuring never-before-heard commentary from Eric recorded just before the original 1992 performance, the release offers fresh insight into the inspiration behind the songs and includes tracks not featured in the original MTV airing.
Crafted from 92/8 phosphor bronze, Clapton’s Choice Signature Strings are known for their warm, rich tone, smooth feel, and long-lasting performance. They're the same strings Eric uses in the studio and on stage--including during his current eight-night residency at the Nippon Budokan in Tokyo--and he calls them "the sound that I demand."
Whether you're chasing Eric's iconic tone or simply looking for strings that deliver great sound and playability, now is the perfect time to pick up a pack--available in a music store near you or online at
martinguitar.com--and celebrate two decades of signature sound.
Jackson's new Pro Series Signature Misha Mansoor Juggernaut guitars, including the HT6 and ET6 models, are designed for classic and progressive metal players. Featuring premium construction, innovative pickups, and advanced bridge options, these guitars deliver the modern sound and performance needed to ignite your tone. Visit jacksonguitars.com for more information.
Jackson is once again partnering with Misha Mansoor to release three new signature guitars, The Pro Series Signature Misha Mansoor Juggernaut HT6 in Red Crystaland Blue Sparkle and The Pro Plus Series Signature Misha Mansoor Juggernaut ET6 in Riviera Blue. Developed in close partnership with Misha, these Juggernaut metal guitars are built to withstand the demands of Misha’s steadfast and fleet-fingered technique. Perfect for both classic and progressive metal players, these guitars deliver the modern sound that every shredder needs to ignite their tone.
“This refresh came about because every few years we want to see what we can do…these guitars travel around the world and they need to be road ready,” said Misha Mansoor on his new signature guitars.“It’s a no-nonsense guitar that looks good, sounds good, and plays good.”
Djent forefather, Misha Mansoor, has gained widespread acclaim as the mastermind behind the axe-centric progressive metal band Periphery. Based in Washington D.C., Periphery is renowned for pushing the limits of progressive metal, using detuned, extended-range instruments to craft a sound that is both technically complex and unapologetically heavy. Misha Mansoor, guitarist and producer, co-founded the band in 2005. With the same precision and innovation that defines Misha's playing, the Juggernautsignature gives players the power to transform their sound.
The premium Juggernaut models feature a 25.5” scale length, poplar body, and bolt-on caramelized maple neck with graphite reinforcement, wrap-around heel, and oiled back finish for greater playing comfort. With a 20” flat radius ebony fingerboard that features rolled edges, fans can enjoy blazing fast leads. These models feature 24 jumbo stainless steel frets and offset dot inlays. Lastly, the Luminlay side-dots will guide the guitarist's path even on the darkest of stages, while the heel-mount truss rod adjustment wheel allows for convenient neck relief tweaks.
Misha worked closely, as he did with past models, to develop the exceptional uncovered direct-mount Jackson MM1 pickups. Unwilling to sacrifice tone, these pickups can be shaped with a five-way blade switch, single volume control, and a single tone control with push/pull feature that allows for players to engage or disengage tone options. Designed for articulate heavy picking, the humbuckers deliver a well-balanced sonic range with rich dynamics, intentionally left uncovered to enhance brightness and clarity.
The Pro Plus Series Signature Misha Mansoor Juggernaut ET6 comes equipped with an EverTune F6Model bridge, engineered to maintain perfect tuning and intonation across the entire neck, even with low tunings. Its counterpart, the Pro Series Signature Misha Mansoor Juggernaut HT6, features a string-through-body hardtail bridge that delivers enhanced sustain, rock-solid tuning stability, and simplified string changes. Both bridges are built to withstand intense playing conditions, providing the unwavering stability essential for Misha's signature heavy metal style.
“We’re beyond thrilled to be partnering with Misha Mansoor on his latest signature guitar collection. His innovation and vision perfectly align with our passion for pushing the boundaries of tone and design, ”said Jon Romanowski, VP of Product of Jackson Guitars. “This collaboration reinforces Jackson’scommitment of providing for players who demand nothing but the best.”
For more information, please visit jacksonguitars.com.
Introducing The Pro Plus Series Misha Mansoor 6-String Juggernauts | Jackson Guitars - YouTube
“The Archon Classic is not a reissue of the original Archon, but a newly voiced circuit with the lead channel excelling in ’70s and ’80s rock tones and a hotter clean channel able to go into breakup. This is the answer for those wanting an Archon with a hotrod vintage lead channel gain structure without changing preamp tube types and a juiced up clean channel without having to use a boost pedal, all wrapped up in a retro-inspired cabinet design." - Doug Sewell, PRS Amp Designer
Matteo Mancuso's first headline national tour of North America includes stops in major cities such as Boston, Brooklyn, Chicago, and Denver, showcasing his unique talent and original sound. Don't miss the opportunity to witness this rising guitar virtuoso live in concert.
Matteo Mancuso has announced his first headline national tour of North America. The itinerary brings Mancuso coast to coast in the US, and into Canada for several annual marquee events. The tour begins on May 20 at Boston’s City Winery and wraps on June 30 at Le Festival International de Jazz de Montreal. With the on-sale being staggered, please check local box offices for on-sale details market to market.
Mancuso hails from Sicily, nestled in the Mediterranean Sea to the South of Italy. The island has always had a rich cultural heritage, from poets, writers, philosophers, and architects to painters and musicians. Born in 1996 and raised just outside the capital Palermo, the pedigree runs deep in the veins of those from the region. Had his family relocated to the US, he might be the best-kept secret in the lineage of great Italian-American players like Zappa, Vai, Satriani, Di Meola, Petrucci, and Gambale.
During the 1970s, his father, Vincenzo Mancuso, made a name for himself as a gifted session player on the domestic scene, and the young Matteo looked up to him as a primary source of inspiration. While still in high school (music), he picked up classical guitar and transverse flute. It didn't take long for everyone to understand that a child prodigy was blooming.
At the age of 12, Matteo took his first steps onto the stage at a local jazz festival. Since then, his acquaintance with live performances has seen him blossom and develop through various line-ups and collaborations with the finest local musicians, including a duo with his father, where they explore the complexities of Django Reinhart's repertoire and contemporary jazz classics.
As a multi-faceted player, either classical or electric, what is astounding is his one-of-a-kind technique and use of his fingers instead of regular picking. With an impressive tone, original sound, and humble demeanor, you have the guitarist no one has ever seen and whose talent puts him in a different league. Many of the world's most iconic, ground-breaking, and legendary players are declaring Matteo as a force to be reckoned with, from Joe Bonamassa and Steve Vaito Al Di Meola.
In 2019, Yamaha Guitars became the official endorser of his appearance at the NAMM show in Los Angeles. He was invited as a judge on the panel for the "Young Guitar Festival" in Bangkok and a masterclass tour in Russia – calling through Moscow, St. Petersburg, and Perm. In 2020, Matteo put together a new trio and began developing his solo work, pushing his compositional boundaries and original material. When the pandemic brought the world to a standstill like many, Matteo experienced difficulties as it took a significant toll on the music industry, like many others. In 2021, as soon as live gigs became possible, he hit the road as part of the new trio, culminating in two exhilarating sold-out nights at the Blue Note in Milano. The name Matteo Mancuso was beginning to reach the ears of the most prominent people in the industry and those in the know. Offers came up from the north to the deep south.
In 2022 he played at the Bremen International Festival at the Auditorium Parco Della Musica in Rome. After a short break in June last year to graduate in jazz guitar from the PalermoConservatory of Music with honors and honorable mention, he resumed touring. He shared the stage with Al Di Meola on classical guitar on the closing night of the Eddie Lang Jazz Festival and played at the Lugano Jazz Festival in Switzerland, as a guest with prog-rockers PFM and an incredible performance at the New Ross Guitar Festival in Ireland. He appeared in a major prime-time slot on Italy's national Rai TV, at the Uppsala Jazz Festival in Sweden. Finally, he rounded off the year at the Spoleto Jazz Festival back in Italy.
His debut titled The Journey features nine original songs which were recorded at Fico d'IndiaStudios Casteldaccia, Sicily, by his father, Vincenzo Mancuso – a gifted player who also played on the record and co-wrote two songs, "Polifemo" and "Blues For John." The album also features Stefano India (Bass) and Guiseppe Bruno (Drums), with additional musicians Riccardo Oliva(Bass), Gianluca Pellerito (drums,) and Guiseppe Vasapolli (Piano/Organ).
Mancuso began writing songs for the album around 2020. "I didn't really have a specific concept behind the album, but I wanted to do something that wasn't associated with only one genre, so there are some rock-oriented songs like Drop D and some modern Jazz tunes like Polifemo," he says."Drop D" was one of the first songs written for the album, which pays tribute to his teens' hard rock and prog influences such as Led Zeppelin, Deep Purple, Yes, Emerson, Lake and Palmer, and Dream Theater. "It is a mix of typical rock and prog elements and one of the most fun songs to play live," he says.
In front of the album’s release, he shared, "I just want people to hear it," he enthuses. "Music has always been my favorite form of communication, and the thing I love about instrumental music is that there isn't a language barrier. I'm sure that people who don't usually listen to instrumental music can find something interesting from this album."
Mancuso has become one of the hottest guitarists on the planet following the release of his debut album in 2023, The Journey, which featured the singles "Samba Party," which channels the excitement and jubilation of Rio de Janeiro during carnival – but the song itself is anything but samba. Also, "Silk Road, which was dedicated to his hometown Palermo and his Arab-Norman roots and was the follow-up to the album's lead single "Drop D,"
The YouTube sensation has already adorned the front cover of magazines such as GuitarTechniques, which called him "The Hottest Guitarist on the Planet ", and Total Guitar, which hailed him as the "World's Hottest Virtuoso." He has picked up plaudits from some of the world's most iconic, ground-breaking players who are declaring Matteo as a force to be reckoned with, from Joe Bonamassa and Steve Vai to Al Di Meola. They share:
"The evolution of guitar is firmly secure in the hands of these kind of players... it's just a new level, the tone, the touch, the notes!" - Steve Vai
"An absolute talent; his improvisational ability is light years ahead. It would take two or three lifetimes. It was like when Jacko (Pastorius) came on the scene...how did he get so good and so fast?" - Al Di Meola
"All the kids are talking about it, and I blanked when answering who my new favorite guitarist is... here he is, Matteo Mancuso. I have not seen anyone reinvent like this since Stanley Jordan" - Joe Bonamassa
For more information, please visit matteomancuso.net.
Confirmed Appearances Include:
- 5/20 Boston, MA City Winery Boston
- 5/21 Brooklyn, NY Brooklyn Bowl
- 5/22 Ardmore, PA The Ardmore Music Hall
- 5/23 Red Bank, NJ The Vogel
- 5/24 Washington, DC The Hamilton Live
- 5/25 Cumberland, MD Allegany County Fairgrounds
- 5/27 Pittsburgh, PA City Winery Pittsburgh
- 5/28 Lansing, MI Grewal Hall at 224
- 5/29 Ferndale, MI The Magic Bag
- 5/31 Cincinnati, OH The Ludlow Garage
- 6/01 Kent, OH The Kent Stage
- 6/02 Indianapolis, IN The Vogue
- 6/04 Minneapolis, MN The Dakota
- 6/05 Milwaukee, WI Vivarium
- 6/06 Chicago, IL Garcia’s
- 6/07 Chicago, IL Garcia’s
- 6/10 Denver, CO Cervantes’ Other Side
- 6/13 Sante Fe, NM The Bridge at Sante Fe Brewing
- 6/14 Phoenix, AZ MIM
- 6/15 Tucson, AZ The Rialto Theatre
- 6/16 Solana Beach, CA Belly Up Tavern
- 6/17 Highland Park, CA Lodge Room
- 6/18 San Juan Capistrano, CA The Coach House
- 6/20 Berkeley, CA The UC Theatre
- 6/22 Portland, OR Aladdin Theater
- 6/23 Seattle, WA Neptune Theatre
- 6/24 Vancouver, BC Rickshaw
- 6/25 Victoria, BC Wicket Hall
- 6/28 Syracuse, NY Syracuse Jazz Fest
- 6/29 Buffalo, NY Electric City
- 6/30 Montreal, QC Le Festival International de Jazz de Montreal