JBL Synthesis In-Ceiling & In-Wall Speaker Overview

This is an overview of the JBL Synthesis built-in speakers. A JBL Synthesis system is made up of a home theater receiver or processor as well as the incredible SCL and SSW series of JBL Synthesis speakers. JBL is one of our favorite brands at Audio Advice. When you want the best possible home theater audio experience, JBL Synthesis sets the bar at each of the price points. Unlike most brands that either make speakers or components, JBL Synthesis is an entire system including electronics and speakers designed for delivering reference level dynamics, frequency response, and fast slam that you expect in the most amazing theaters.

If you want to dive deeper into the JBL Synthesis concept, check out our full in-depth JBL Synthesis overview.

Since its beginning in 1992, JBL Synthesis has evolved to cover a wider range of home theater sizes and budgets. JBL has pushed the envelope at the top end of the Synthesis range to incredible levels, but better yet, by using some trickle-down technology, there is now an expanded series of Synthesis components that greatly reduces the price of a complete Synthesis system.

The SCL and SSW models are the meat of a complete Synthesis system. These are a series of speakers and subwoofers you would use for all of your speakers in a Synthesis home theater system.

We will take a look at the features and technology all of these models share, then dive into the differences between them to help you pick the best ones for your dream home theater.

When you are thinking about the preliminary design of your home theater room, we have developed a great tool for you, and it's free! You can enter your room dimensions and play around with different types of speaker configurations to see what types would work best for your space.

Audio Advice is the only dealer in the US authorized by JBL for online sales and support. Our team of experts can help you design your ultimate JBL Synthesis home theater, then using video chat and remote login, help you perfectly configure and calibrate your system. Now let's look at some of the reasons we love the JBL built-in speakers.

Example of a custom designed JBL Synthesis Home Theater room..

Designed For Acoustically Transparent Screens

To recreate the true movie theater experience, it is always best to locate the main front three speakers behind an acoustically transparent screen. This makes the audio appear to come right from the action, which is so much more immersive than speakers to the sides, under, or above your screen.

All of the SCL models are either designed to be mounted in a wall or slender enough to fit behind a movie theater-like screen.

D2 State of the Art Speaker Technology

JBL designed a new type of speaker for touring sound using a new type of compression driver they call D2. It has received 3 US Patents for its unique technology. Their VTX touring system with D2 compression drivers and waveguides can deliver a very consistent sound across a large area, making it perfect for both large and small-scale concerts. When you pair a compression driver with a horn-type waveguide, you also greatly increase its efficiency when you compare it to a traditional dome or cone driver found in most home theater speakers. Most dome tweeters are about 5% efficient whereas the JBL compression driver coupled with its patented waveguide gives you anywhere from 20-50% depending on the model. That is a huge difference!

JBL has taken the normal type of horn waveguides and looked at ways to improve their linearity. They developed what they call their HDI waveguide which delivers completely linear sound in all directions from the guide. Not only is the sound linear, but there is far less distortion than a cone or dome type driver with the ability to play far beyond the range of human hearing.

This same driver filtered down into the Synthesis models with JBL developing 4 different versions of it that share the same tech. The dynamics you experience from a JBL D2 driver paired with the HDI waveguide are just spectacular! Nothing we have ever heard can produce the dynamics and slam you get from a JBL Synthesis system!

We love the fact that JBL makes all of their own drivers, plus they put a name on each one so it is super easy to compare models rather than wondering just what driver a speaker company used. In the individual speaker overviews, we will go over each one specifically.

Extremely Well-Built Bass Drivers

To mate up with the D2 drivers, JBL has designed some of the most stout-looking woofers you will find. These all use cast frame baskets with massive magnet assemblies. In the case of the in-wall and in-ceiling models, the frames they are mounted to are incredibly solid. Some of the drivers used in the subwoofers weigh more themselves than you would expect for an entire speaker. Just like with the D2, JBL is taking tech from their professional speakers and trickling it down into their more affordable consumer products.

Designed To Complement Each Other

We really like that JBL now gives us a really wide range of choices for their Synthesis SCL speakers. With all of them using a version of the D2 driver with similar woofer tech, you can mix and match combinations to come up with the best setup for your environment and budget.

Now let’s take a look at each model in the SCL and SSW series.

JBL Synthesis In-Wall Speaker Models

JBL Synthesis SCL-7 2-Way 5.25" In-Wall Speaker

The entry-level in-wall SCL-7 is by no means an entry-level speaker! It uses the 2410H-2 driver coupled with two 5 ¼” woofers in a two-way design. The woofers are made from a special aluminum matrix material housed in a heavy-duty cast basket. The high-frequency driver in the SCL-7 is not mounted in the center, but off-axis with an angled HDI waveguide. This makes it perfect for some pretty interesting applications.

The waveguide is tilted at a 15-degree angle and with the symmetrical shape of the speaker, this means you can aim it in different directions. We see a lot of applications for the SCL-7.

In the diagram to the right, you can see the SCL-7's rear surround coverage - 30 degrees to the wall and 60 degrees inside. With this configuration, you get less sidewall reflection and more coverage.

JBL Synthesis SCL-7 Coverage Diagram

Wide Surround Speakers
With new Dolby Atmos speaker configurations and the latest processors, including those from JBL Synthesis, you can now add a wide surround speaker that goes on the left and right walls in between your main front and main surround speakers. The 15-degree angle makes them perfect for this position when you mount them vertically.

Center Channel Above a Screen or Flat Panel TV
If you are using a large flat panel or projection screen that is not acoustically transparent, the challenge is putting the center channel speaker in a position where it will direct the sound at the main seats. The SCL-7 can be positioned above the screen which will angle the sound right at the listening area. It can easily cover three rows of seats and by angling the sound downward, you get far fewer sound ceiling reflections as compared to a conventional front-firing in-wall speaker.

Main Left and Right Speakers
If you have a situation where you have to spread your left and right speakers very far apart compared to how far you are sitting from them, the angled waveguide on the SCL-7 will direct the sound more into the main seats, while also minimizing sound that might reflect off the near side walls.

Surround or Rear Channels
In some situations, a speaker that fires totally on-axis may not be the best choice if you need to position your surround speakers in front of or behind the main seats or if you have to spread your rear channels far apart.

As you can see, the SCL-7 is a super flexible model designed to overcome issues that used to be problems.

JBL Synthesis SCL-6 2.5-Way Quad 5.25" In-Wall Speaker

The SCL-6 uses four of the same woofers used in the SCL-7 in a 2.5-way design. The 2410H-2 high-frequency D2 series driver is mounted centered between the woofers for on-axis listening.

We think the SCL-6 is the best value in the entire lineup. It delivers extremely dynamic sound that can also reveal very subtle details for a surprisingly low price.

Perfect for Acoustically Transparent Screens
Three of these as the left, center, and right channels behind an acoustically transparent front projection screen will be ideal for a great home theater. They are only 31” tall but deliver unbelievable impact. We have tested lots of different types of speakers over time. What you will find from the JBL Synthesis speakers is that they are the real deal. Just lifting them and feeling the weight of the magnets and electronics compared to other similarly priced solutions will win you over. The SCL-6 is no exception here.

Perfect for Acoustically Transparent Screens
Three of these as the left, center, and right channels behind an acoustically transparent front projection screen will be ideal for a great home theater. They are only 31” tall but deliver unbelievable impact. We have tested lots of different types of speakers over time. What you will find from the JBL Synthesis speakers is that they are the real deal. Just lifting them and feeling the weight of the magnets and electronics compared to other similarly priced solutions will win you over. The SCL-6 is no exception here.

Surround and Rear Channels
These will also be great for an entire system, using them for all the channels; or they would be great surround and rear channels for a system with the more expensive front three. Their very wide and linear on-axis dispersion makes them well suited for surrounds and rears when you can position them as you normally would in a typical home theater room.

Compared to the SCL-7's rear surround coverage, the SCL-6 covers 40 degrees to both the wall and inside angles. With this configuration, you get more sidewall reflection and slightly less coverage.

JBL Synthesis SCL-6 Coverage Diagram

JBL Synthesis SCL-4 2-Way 7" In-Wall Speaker

When you move to the SCL-4, you get the more advanced D2 driver called the 2409H. In much larger rooms, we consider these a pretty big step up from the SCL-6. They also use a single 7” aluminum matrix woofer with everything mounted in a custom-designed, solid backbox.

In larger rooms, these have the ability to provide more sound pressure levels. The big deal to use in these though is their ability to be bi-amplified. All of the JBL Synthesis speakers have incredibly good passive crossovers, but when you actively bi-amp a speaker, you totally eliminate the passive crossover, resulting in sound that is so much more effortless.

Of course, this does come at a cost as you will need a JBL crossover and two amps, but the jump up in performance is serious.

These have the same applications as the SCL-6 for your main speakers and surround and rear channels with upgraded sound.

We see using these as the main front three paired up with the less expensive SCL models for surrounds, or these can mate up with the next two models up for the surround and rear channels.

JBL Synthesis SCL-2 2.5-Way Triple 8" In-Wall Speaker

Now we are getting into something really serious. If you have a large room and want reference level impact and dynamics, the SCL-2 may be just what you need. These step up to the D2415K D2 driver which uses a 1 ½” dual voice coil driver, compared with the 1” single coil of the lower models. This is matched up with three 8” aluminum cone matrix drivers for a 2.5-way configuration.

Like the SCL-4, the SCL-2 comes with its own sealed enclosure. However, there is one catch to this massive and solid cabinet- it needs a 6” deep stud bay for installation. Like the SCL-4 these can also be bi-amplified using JBL crossovers and 2 amplifiers.

We recommend the SCL-2 for larger home theater rooms. While these are twice the price of an SCL-4 and 4 times that of an SCL-6, they can deliver dynamics and slam that are unheard of at this price level. Plus the D2415K driver is just super sweet and open on the top end with never any sense of strain no matter how hard you push it.

The SCL-2 fits into the same family of applications as the SCL-6 and SCL-4 making them great left, right, and center channels, and surround and rear channels for a very serious home theater. Just bear in mind you need 6” stud bays to build them in.

Even though these are not inexpensive, there are plenty of home theater speakers that sell for more than double their price that can not deliver the amazing home theater sound these are capable of. We do suggest if you are going to invest at this level that you go ahead and bite the bullet to bi-amp them using a JBL Synthesis crossover/Arcos EQ system and two great power amps.

JBL Synthesis SCL-1 2-Way 12" In-Wall LCR Speaker

The SCL-1 is JBL’s latest speaker made to give you the very ultimate in-home theater performance. In their massive shipping crate, they weigh over 300 pounds each and even out of the box are close to 200 pounds!

These are designed to be built in behind a screen and with their almost 15” of depth, you will need to do some advanced room planning to make sure you can accommodate them behind your acoustically transparent projection screen.

You get the best of the best with the SCL-1 as it uses the top-of-the-line D2 series driver, the D2430K dual 3-inch compression driver mounted to their best High Definition Imaging waveguide. JBL developed a brand new 12” woofer for the SCL-1 which uses a cast-frame Carbon Cellulose Composite cone. And there is not one but two!!

JBL’s patented CBAS™ enclosure was used to house this incredible speaker. This system combines the benefits of both sealed and vented enclosures. JBL uses 1” thick MDF with extensive bracing inside the cabinet. Another side advantage of their Complimentary Bass Alignment System is the fact the vents are on the front making it ideal for built-in applications.

We see the SCL-1 being used primarily as an LCR speaker, paired up with the SCL-2 for the surround and rear channels.

Like the SCL-4 and SCL-2, the SCL-1 will benefit from bi-amplification.

We know the SCL-1 will not fit into most people’s home theater budgets, but we can say if you have the ability to consider these there is no question you should bi-amp them. Once these are fine-tuned in your room you will have a huge smile on your face every time you turn your home theater on! And it is not only about a system with lots of impact that can play incredibly loud. This speaker (along with the less expensive JBL 4367 floor stander) has silky smooth highs with the ability to resolve tiny little details only the very best high-performance speakers on the market can do. If you want home theater sound that is second to none and will make any audiophile completely jealous, look no further than the SCL-1.

JBL Synthesis In-Ceiling Lineup

JBL Synthesis In-Ceiling Speaker Models

SCL-8 2-Way 5.25" In-Ceiling Speaker

The SCL-8 is a two-way in-ceiling model using the same drivers as the SCL-6 and SCL-7. They have the 2410H-2 high-frequency driver and the 5 ¼” aluminum matrix cone woofer. It comes with a round or square grill frame.

What is pretty neat about this one and the SCL-5 is the way JBL mounted the high-frequency driver and its waveguide. They mounted them at an angle that presents a perfectly centered sound at 45 degrees off-axis from the speaker itself. This waveguide has such linear dispersion that you still have consistent sound at plus or minus 30 degrees from that 45-degree position.

In real-world terms, this means one pair of SCL-8’s can easily cover up to three rows of seats with the same frequency curve. That is impressive! This gives them a lot of use cases.

Main In-Ceiling LCR speakers
For family rooms where there is no place to mount speakers in front of your TV, the SCL-8 is great when you use three across the front-mounted in the ceiling near your TV. Their dispersion pattern will send sound deep into your family room for great coverage

Atmos Height Speakers
This will probably be the most common use for the SCL-8. They will be a great match to whatever SCL speaker you use for your lower channels and when used either as a single pair or two pairs of height speakers completely cover up to three rows of seats with ease

In-Ceiling Surround Speakers
While we normally recommend you keep your surround speakers at ear level, we do realize there are some rooms where that is just not practical and the surround speakers must be placed in the ceiling. You can turn the round speaker to direct it towards your seats and their wide dispersion will assure you of good coverage.

JBL Synthesis SCL-5 2-Way 7" In-Ceiling Speaker

If you were to take an SCL-4 and put it into the same type of mounting system as the SCL-8, you'd have the SCL-5.  It steps up to the better 2409H high-frequency driver and 7” aluminum matrix woofer of the SCL-4 with the same angled design as the SCL-8. The diagram below gives you a good idea of the coverage you can expect from both models.

JBL Synthesis SCL-5 nd SCL-8 Coverage Diagram

We see these having identical applications as the SCL-8 with both better resolution and the ability to play louder with more impact in larger rooms. The SCL-5 is the perfect Atmos height speaker for systems based on the SCL-4, SCL-2, and SCL-1.

JBL Synthesis SCL-3 2-Way 5.25" In-Ceiling & In-Wall Speaker

This is an older model. It has the same high-frequency driver as the SCL-5 with two 5 ¼” woofers built into a sealed back box. The SCL-5 costs a little bit less and goes deeper in bass performance.

The only application we could think of where you might want to use these is if you had very limited front-to-back depth for height channels or you were doing 3 pairs of in-ceiling Atmos height speakers and needed something that fired straight down.

Our advice is that in 99% of applications the new SCL-5 is the better speaker to use versus SCL-3.

JBL Synthesis HDI Series Speaker Models

We wanted to point out a pretty neat fact about some of the new SCL models.  When JBL introduced their HDI line of in-room speakers based on the 2410H-2 high-frequency driver, we fell in love with their sound.  However, we asked JBL, when they would have matching in-ceiling and in-wall speakers for a complete surround system.  The answer is now with the new SCL-6, SCL-7, and SCL-8 as these are perfect matches.  Thank you JBL for adding these to compliment one of our favorite in-room speaker systems.  

JBL HDI Tower Speakers on either side of a media console

We wanted to point out a pretty neat fact about some of the new SCL models. When JBL introduced their HDI line of in-room speakers based on the 2410H-2 high-frequency driver, we fell in love with their sound. However, we asked JBL, when they would have matching in-ceiling and in-wall speakers for a complete surround system. The answer is now with the new SCL-6, SCL-7, and SCL-8 as these are perfect matches. Thank you JBL for adding these to compliment one of our favorite in-room speaker systems.

JBL Synthesis Subwoofers

Bass is the foundation of music, and great, impactful deep bass is the key to a fabulous home theater system.  JBL has four models of subwoofers in their Synthesis lineup.  

We should let you know, none of these come with an amplifier as JBL makes a series of amps you can use with them.  The power level you need will depend on both the subwoofer you choose and the size of your room.  Your home theater installation company will know exactly how to match them up. Give us a call or stop by one of our stores if you have questions — Audio Advice experts can easily help you select the best JBL amp for any of their subwoofers.  

JBL Synthesis SSW-4 Dual 8" In-Wall Subwoofer

The entry-level JBL Synthesis in-wall SSW-4 subwoofer uses two 8” metal cone woofers. These cast basket beefy woofers are mounted into a sealed back box that is designed to fit into a standard 2X4 wall. You will need the appropriate power amp to drive them and for almost all situations we recommend a pair of them to provide more even bass output.

There are two main use cases for the SSW-4.

Main Subwoofers
In a smaller room, a pair of SSW-4’s will provide you with good bass output that is totally hidden from an aesthetic and space standpoint. We do have to say they are not going to get down as deep in the lower bass regions as some freestanding subwoofers, but the performance they do offer in the range they cover is very impactful. We are happy to help you decide the best way to go for your theater.

Rear Subwoofers
At Audio Advice, we love a room with 4 subwoofers. You not only get the ability to play much louder, but by having 4 subwoofers in a room, you greatly reduce bass peaks where the bass sound builds up and colors the sound. We can see a pair of SSW-4’s being coupled with the SSW-3 as the 3rd and 4th subwoofer for a system that can deliver super even deep bass.

JBL Synthesis SSW-3 Dual 10" In-Wall Subwoofer

The SSW-3 is a huge jump up from the SSW-4 in our opinion. It uses dual 10” woofers. These are made of a composite cone material and mounted in very beefy cast baskets. The bass drivers have a large 2 ½” voice coil.

The drivers are mounted to a specially designed molded baffle that has all kinds of structural ribbing to provide a very rigid and low resonance mounting surface. The baffle then attaches to a large back box made from ¾” MDF with lots of internal bracing. The baffle is 5.1” deep, so these must go in 2X6 stud walls. It is one huge solid back box too, taking up over 5 feet of height.

This large back box with the dual 10” drivers means you get deep bass that rivals some of the best in-room subwoofers in a package that can be completely invisible.

Two of these coupled to the right JBL Synthesis power amp will rock most home theater rooms.

The use cases we see are just like the SSW-4 where two of the SSW-3 could be used as the main front subwoofers, or you could add two for in-wall 3rd and 4th subs if you were doing either of the next two subs in the lineup.

The next two subwoofers in the lineup are some seriously large subwoofers with the ability to put out full and clean deep bass that will literally move your pants legs! These are large and that fact will need to be considered when designing your room. While most systems will use the SSW-3 or SSW-4, or the HDI in-room subwoofer, these are just so cool we had to go over them briefly.

JBL Synthesis SSW-2 Dual 12" In-Wall Subwoofer

These borrow a lot of tech from the pro side of JBL where they have to produce bass cabinets that can rock an outdoor stadium. JBL uses dual 12” composite cone woofers mounted in a very large 33” x 19” x 15” enclosure you can stand on its side or lay down.

The woofers themselves have a 4” voice coil for incredibly high power handling and fast, deep bass. The two front-firing ports use JBL’s patented Slipstream™ technology to minimize any port noise. When you use 1” thick MDF with loads of internal v-bracing and put those huge drivers in it, you wind up with a cabinet that weighs in at 181 pounds!

To experience a pair of these with the right amplifiers is really something special. They are just super fast, yet go incredibly deep for bass that will compliment the finest home theaters.

We see these typically mated up with the SCL-2 or systems where we use the in-room JBL 4367 behind an acoustically transparent screen.

JBL Synthesis SSW-1 Dual 15" In-Wall Subwoofer

This has to be one of the most serious subwoofers on the market at any price. When you consider it comes from a company that has been delivering great bass performance at concerts since before the time of Woodstock, you know it has got to be something really special.

JBL starts out by using a newly developed 15” woofer that sports a 6” voice coil giving it up to 2500 watts of power handling capability. They chose an aluminum matrix type material for the woofer cone.

When you look at the SSW-1, it basically looks like an SSW-2 on steroids, but there is one very big difference. The SSW1 needs one power amplifier for each of its two 15” woofers! Plus it is almost twice as big and twice as heavy! This guy is a beast!

If you have a larger home theater room and want what is probably the best possible bass experience on the market, use a pair of these mated up with the right JBL amps and have them tuned to the Harman target curve and you will have bass that goes deep but reveals all kinds of subtle textural details.

Overall Recommendation

We hope this overview of the JBL Synthesis SCL and SSW lineup has helped you get started on thinking about having Audio Advice design your own custom JBL Synthesis system. Be sure to check out our incredible 9.4.4 JBL Synthesis Home Theater Install Customer Showcase to see many of these products in action!

At Audio Advice, we've been designing and installing high-performance home theaters & smart home systems for our customers in Raleigh and Charlotte, North Carolina, and surrounding areas for decades. In fact, we've delivered more custom theaters than anyone in the Southeast! We are now offering Home Theater Design no matter where you live in the United States! If you are interested in a custom home theater or upgrading your current system, give us a call at 888.899.8776, chat with us, or stop by our Raleigh and Charlotte, North Carolina showrooms. We can't wait to help you build your ultimate home theater!


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