The MartinLogan Motion 4i bookshelf speaker comes from a company well known for its distinguished line of high-end speakers.

MartinLogan Motion 4i Bookshelf Speaker

I’ve never owned a MartinLogan product but have been wowed by their sound at high-end dealers and audio shows. I was anxious to see how the company could translate their expertise into a relatively low cost design that could provide excellent sound at a very reasonable cost.

The MartinLogan Motion 4i speakers did extremely well in the context of their diminutive size and price. They provide a stable stereo image, lovely smooth high frequencies from their Folded Motion design tweeter. The bass is thin, but the company offers its own subwoofers.


MartinLogan Motion 4i Bookshelf Speaker

  • Excellent sound at this price point
  • Exceptional high frequency reproduction and wide dispersion
  • Nicely finished with glossy piano black exterior
  • Excellent setup booklet
  • Magnetic mounted grille
  • Deep bass needs help from a subwoofer
  • Requires moderate to high amplifier power to sound their best

MartinLogan began in the late 1970s when Gayle Martin Sanders and Ron Logan Sutherland met in Kansas. They were interested in producing a high-end, reliable electrostatic speaker system, and by the 1980s their signature speaker, the Monolith was meeting with excellent reviews. Now, the company has a full line of electrostatic speakers and about 15 years ago started looking at lower cost systems and got much praise with an earlier version of the speaker we’re reviewing here, which was called the Motion 4 Speaker. The ‘motion’ in the title comes from the tweeter, the much lauded Folded Motion transducer. Invented in the 1970s by Oskar Heil, originally marketed by ESS speakers, the tweeter now appears in several variations from a variety of manufacturers.

MartinLogan Tweeter

Frequency Response:

70–23,000 Hz ±3dB

Horizontal Dispersion:

80 degrees

Vertical Dispersion:

80 degrees

High Frequency Transducer:

1 × 1.4-inch (2.6cm × 3.6cm) Folded Motion Transducer with 5.25 × 1.75-inch (13.3cm × 4.4cm) diaphragm

Low Frequency Transducer:

4-inch (10.2cm) paper cone with stamped steel basket. Non-resonant asymmetrical chamber format. Rigid structured dust cap to reduce cone break-up modes. Folded bass reflex port.


90 dB/2.83 volts/meter


4 Ohms Compatible with 4, 6, or 8 Ohm rated amplifiers.

Recommended Amplifier Power:

20–150 watts per channel

Crossover Frequency:

2900 Hz


Custom air core coil and low DCR steel laminate inductors; polyester film capacitors in series and low DF electrolytic capacitors in parallel; overall system thermal/current protection.


Push style with banana jacks


6 lbs. (2.72 kg)


12.6 inches x 5.6 inches x 5.7 inches (32cm x 14.3cm x 14.5cm)


$249.95 each (1 speaker)




MartinLogan, MartinLogan 4i speakers, bookshelf speakers, Bookshelf Speakers Review 2019

MartinLogan no grille

The MartinLogan Motion 4i joins a crowded field of bookshelf speakers. Although designated a bookshelf speaker, the 4i’s can easily be mounted on a wall, with the included hardware, or placed on stands.

Setting up the speakers is dead easy. Each speaker comes in an individual box, and includes protective pads for the bottom of the speaker, and hardware for wall mounting. I used the speakers on a table top, and on a long credenza allowing me to adjust the distance from the wall to get the most bass out of the ducted port at the back.

The MartinLogan Motion 4i speakers have robust spring-loaded clips for attaching speaker wires, and also offer banana connectors which I used in my listening rooms, since I am frequently switching speakers in and out for review.

MartinLogan binding Posts

In Use

The speakers were a pleasant surprise, given their small size, and relatively modest cost. The high frequencies using the folded tweeter design are exemplary. I also noticed a very wide dispersion in both the mid- and high- frequencies. This makes placement easier simplifying setup.

The speakers really don’t produce much bass. With a test disc with low frequency sweeps I heard hardly anything below 70 Hz, but that’s not a surprise given the size and price of these speakers. MartinLogan offers subwoofers for these speakers, but none were provided for the review and my Klipsch R10SWI wireless subwoofer added quite a bit to the overall sound.

Without the subwoofer running, the speakers delivered a nice low end for their size, and for non-critical listening I was happy with the overall balance.

Listening to a variety of material in my master bedroom where I have a stereo setup was most interesting. My permanent speakers are KEF LS50’s, which I consider near state-of-the-art. They are triple the cost of the MartinLogan speakers, and I was surprised how well the MartinLogans compared. High frequencies were very similar. The KEFs also benefit from the same Klipsch Subwoofer, so the most differentiation between the two very differently priced speakers was in the midrange, where the KEFs were smoother and slightly more detailed and forward. Switching back and forth, the KEFs were stunning. The MartinLogan Motion 4i speakers were very good.

Having said that, the sound from the MartinLogans was smooth (except where it was slightly depressed in the midrange).

Without the subwoofer attached, the KEFs did better in the low end, offering useful frequency response down to 45-50 Hz, a good deal lower than the MartinLogan speakers. But as I always listen with a subwoofer, the differences don’t make much practical difference to me.

The speakers are fairly easy to drive, but you want a high quality amplifier or receiver. I used Emotiva UPA-500 amps, and a Denon AVR-S640H receiver with good results.

Listening tests:

I auditioned a variety of CDs, and also several high resolution files that I knew would challenge the speakers. Since I know the tracks I played very well, it was easy to notice differences between speakers.

The Rothko Chapel

Morton Feldman “The Rothko Chapel”
This is an excellent musical test. This contemporary work features voices, percussion and strings. It is an excellent test of ambiance reproduction, and directionality, as instruments pop out of the sound field at extreme left and right speaker. The 4i speakers acquitted themselves on this tough musical test.


Rachmaninoff “Vespers”

This is a Pentatone SACD from 2002 that has lovely choral music. Once again the MartinLogan speakers were able to offer precise placement of the voices making for a realistic presentation.

Starship Troopers

Basil Poledouris “Starship Troopers Deluxe Edition”

This soundtrack from the 1997 alien bugs movie has a large orchestra, percussion effects, and some electronics. The 4i speakers kept the sound congestion free, quite an accomplishment for small drivers.

Theme of Secrets

Eddie Jobson “Theme of Secrets”

Jazz and New Age music that has a nice mix of acoustic and electronic instruments. The 4i speakers offered excellent separation, with highs smooth and realistic.



A lot of technical knowledge and clever engineering went into the design of the MARTINLOGAN MOTION 4I BOOKSHELF SPEAKERS. They’ve succeeded at a low price.

  • Excellent high frequency reproduction
  • Very wide dispersion
  • High quality materials, and speaker connectors
Would Like To See
  • A version with better low end
  • A package price with included subwoofer for a 2.1 system.
  • A more forward or elevated mid-range

I didn’t expect these speakers to outperform higher cost speakers like my KEFs, and they didn’t. What was remarkable was how well they did. There’s no deep bass here, but even the KEFs need a subwoofer. At this price range, the MartinLogan Motion 4i bookshelf speakers are a fine value. I wouldn’t consider them for a main system in a large room, but in a bedroom, an office or similar smaller space they offer wide dispersion, a clean non-congested sound, fine high frequencies from the folded motion tweeter design, and contemporary looks with a shiny, piano black enclosure. A speaker this good needs a subwoofer to truly sound complete. MartinLogan offers matching subwoofers, and has just started shipping a 5.1 configuration based on 4 of their smaller motion 2i speakers, a Motion 6i center channel and their Dynamo 400 subwoofer. I’’d like to see a 2.1 package as well.