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Definitive UIW RLS II vs JBL Studio 6 66LCR Comparison

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Definitive UIW RLS II

Passive In-wall | 22-30kHz

Definitive Technology UIW RLS II
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JBL Studio 6 66LCR

Passive In-wall | 45-20kHz

JBL Studio 6 66LCR
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Definitive UIW RLS II Definitive UIW RLS I...
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JBL Studio 6 66LCR JBL Studio 6 66LCR
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Definitive UIW RLS I...
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JBL Studio 6 66LCR
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Definitive UIW RLS II vs JBL Studio 6 66LCR Speaker Comparison

In this review, we will be comparing UIW RLS II and Studio 6 66LCR, two Passive In-wall speakers from Definitive Technology and JBL.

Let's have a brief look at the main features of Definitive UIW RLS II and JBL Studio 6 66LCR first before getting into our more detailed comparison.

Definitive UIW RLS II Key Specs

  • 2-way Design
  • 1" Hard-Dome Tweeter
  • 2 x 6.5" Polypropylene Woofer
  • 22-30kHz Frequency Response
  • 92 dB Sensitivity
  • Impedance: 8ohms
  • Power Range:10-350watts
  • Dimensions (H x W x D): 724.0" x 7.0000" x 3.8750"( 724.0 x 178.0 x 99.0mm )

JBL Studio 6 66LCR Key Specs

  • 2-way Design
  • 1" Horn-Loaded Tweeter
  • 2 x 6.5" PolyPlas Woofer
  • 45-20kHz Frequency Response
  • 94 dB Sensitivity
  • Impedance: 6ohms
  • Power Range:10-150watts
  • Dimensions (H x W x D): 443.0" x 7.1250" x 3.7500"( 443.0 x 181.0 x 96.0mm )

What size room are the Definitive UIW RLS II and JBL Studio 6 66LCR speakers good for?

The size of the room in which you are planning to use these loudspeakers is an important decision factor. Here we have compared their suitability to various sizes of environments considering their size and max power parameters:

Listening Environment* Definitive UIW RLS II JBL Studio 6 66LCR
Near-field Are you nuts? Poor
Small Room Bad Average
Mid-size Room Poor Good
Large Room Good Average
Very Large Room Good Poor

(* Approximate Room sizes: Small < 100sq. ft / 9 m2, Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: > 400 sq. ft / 36 m2. Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual listening experience changes depending on floor height, room shape, surface materials, listening position, speaker locations, etc.)

In the following sections, we will get into more detail in order to better understand how the Definitive UIW RLS II and JBL Studio 6 66LCR compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.


**This post contains affiliate links, and I will be compensated if you make a purchase after clicking through my links. As an Amazon Associate I earn from qualifying purchases.


Drivers

Both UIW RLS II and Studio 6 66LCR are 2-way speakers.

Driver Definitive UIW RLS II JBL Studio 6 66LCR
Driver Setup 2-way 2-way
Tweeter 1-inch 1-inch
Midrange - -
Woofer 2 x 6.5-inch 2 x 6.5-inch

UIW RLS II features a 1" Hard-Dome Tweeter and 2 x 6.5" Polypropylene Woofer . On the other hand, the Studio 6 66LCR features a 1" Horn-Loaded Tweeter and 2 x 6.5" PolyPlas Woofer .

Frequency Response

UIW RLS II has a frequency range of 22-30kHz whereas Studio 6 66LCR has a frequency range of 45-20kHz. With a minimum frequency of 22Hz, the UIW RLS II can go significantly deeper on the low side and provide stronger bass compared to the Studio 6 66LCR's min frequency of 45Hz.

Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the In-wall class in our database.

Low Frequency

In-wall Speakers

UIW RLS II
Studio 6 66LCR
Min
Average
Max
High Frequency

In-wall Speakers

Definitive UIW RLS II
JBL Studio 6 66LCR
Min
Average
Max

None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.

Impedance and Sensitivity

UIW RLS II is a 8 ohms speaker compared to the Studio 6 66LCR which has a nominal impedance of 6 ohms.

These two speakers also have different sensitivity levels. UIW RLS II sensitivity is rated at 92 dB and the Studio 6 66LCR's is rated at 94 dB. This 2 dB difference makes the JBL Studio 6 66LCR a more sensitive speaker compared to Definitive UIW RLS II, hence will play louder with the same amount of watts.

Sensitivity

In-wall Speakers

UIW RLS II
Studio 6 66LCR
Min
Average
Max

Power Range

Power range is the range of input power in watts RMS that a loudspeaker is designed to handle. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.

UIW RLS II can handle a max power of 350 watts RMS from the amp the whereas Studio 6 66LCR has a max power handling value of 150 watts RMS, 200 watts less than the UIW RLS II.

Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters such as Impedance, sensitivity and system efficiencies.

Input Type and Bi-Amping / Bi-Wiring

UIW RLS II features Spring posts type posts and Studio 6 66LCR has a Spring posts type posts. None of these speakers feature bi-amping/bi-wiring.

Physical Specs

Size of a speaker can sometimes become an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Definitive UIW RLS II's and JBL Studio 6 66LCR's external dimensions. Definitive UIW RLS II has external dimensions of 724.0 x 178.0 x 99.0mm ( 28.5000-inch x 7.0000-inch x 3.8750-inch) whereas JBL Studio 6 66LCR has external dimensions of 443.0 x 181.0 x 96.0mm ( 17.4375-inch x 7.1250-inch x 3.7500-inch) .

JBL Studio 6 66LCR is 281mm shorter and 3mm less deeper than Definitive UIW RLS II but it is also 3mm wider.

What's in the Box of Definitive UIW RLS II?

Here are the items that are included inside the box of UIW RLS II:
  • In-wall loudspeaker
  • Grille
  • Self-adhesive foam gasket
  • Paint mask
  • Wall-Mount Template
  • Owners Manual
  • Online Product Registration Card
  • What's in the Box of JBL Studio 6 66LCR?

    Here are the items that come with the Studio 6 66LCR:
  • In-wall loudspeaker
  • Grille
  • Cut-Out Template
  • Quick Start Guide

  • Reasons to choose Definitive Technology UIW RLS II over JBL Studio 6 66LCR
    Max Input Power 350 watts vs 150 watts Handle more power from your amplifier
    Nominal Impedance 8 ohms vs 6 ohms Less selective with amplifiers
    Low Frequency Response 22 Hz vs 45 Hz Generates deeper bass
    High Frequency Response 30k Hz vs 20k Hz Generates higher frequency
    Passive Radiator 2 x 6.5-inch vs None Increases the bass performance

    Reasons to choose JBL Studio 6 66LCR over Definitive Technology UIW RLS II

    Sensitivity 94 dB vs 92 dB Play louder with same amount of amplification power
    Height 443mm vs 724mm Easier to fit in smaller spaces
    Base Surface Area 173cm2 vs 176cm2 Takes less floor space
    Price per pair* 1400USD vs 1998USD costs less (*prices may change depending on the seller, location and time)
    Definitive UIW RLS II vs JBL Studio 6 66LCR Specs Table
    Detailed comparison of specifications
    General Definitive Technology UIW RLS II JBL Studio 6 66LCR
    Brand Definitive Technology JBL
    Speaker Type Passive In-wall Speaker Passive In-wall Speaker
    Power Range 10-350 watts 10-150 watts
    Sensitivity 92 dB 94 dB
    Impedance 8 ohms 6 ohms
    Frequency Response 22-30kHz 45-20kHz
    Drivers
    Woofer Quantity 2 2
    Woofer Size 6.5" 6.5"
    Woofer Composition Polypropylene PolyPlas
    Woofer Surround Material Butly Rubber Rubber
    Tweeter Size 1" 1"
    Tweeter Type Hard-Dome Horn-Loaded
    Aimable Tweeter No No
    Midrange Driver N/A" N/A"
    Physical Specs
    Height 724.0mm (28.5") 443.0mm (17.4")
    Width 178.0mm (7") 181.0mm (7.1")
    Depth 99.0mm (3.9") 96.0mm (3.8")
    Enclosure In-wall In-wall
    Moisture Resistancy Yes No
    Connections
    Biamp Inputs No No
    Other
    Parts Warranty 5 Years 5 Years
    Labor Warranty 5 Years 5 Years

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