MartinLogan Depth i Review

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MartinLogan Depth i Review

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Introduction

Over the last couple of months I have been enjoying the company of a new subwoofer by MartinLogan, a company famous for their electrostatic speakers, and superlative they are with a few people here who own them. I know of a couple of staff members who use MartinLogan speakers and that is what got me thinking about the two subwoofer offerings from MartinLogan, which are the Depth i and Descent i. Both are unique in that they feature three drive units, three 8" drivers for the Depth i and three 10" drivers for the Descent i, versus the one or two driver arrays that are typically used in other sub designs. The MartinLogan Depth i comes in at roughly £2000 here in the UK and about the same in U.S. dollars.

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I have had my fair share of commercial subwoofers over the years, ranging from low end to high end with offerings from the likes of Rel, BK, Velodyne and M&K. The M&K being a hard act to follow due to its high SPL and quite spectacular movie performance. The Velodyne subs I had were dual DD12's, which were no competition for the M&K for both movies and music, but still good subs none the less. The Velodyne DD models have just recently been updated to the DD+ version.


Design, Connections and Setup

The first thing that struck me was the weight of this sub, coming in at approx 32Kg, although it sure seemed to be heavier. It is built to the highest of standards and looks very nice for a subwoofer with three drivers. This is a patented technology by MartinLogan using their TriLinear™ Driver Array and BalancedForce™ Driver Alignment. The Depth i locates the three drivers of its TriLinear™ array precisely 120 degrees apart on the cabinet. Each driver unit is also servo controlled so that the signal is kept intact and distortion kept to a minimum. This design has recently been seen in the new Paradigm SUB 1 and SUB 2, except with six drivers per cabinet.

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Connections and setup was a breeze with all the dials for Gain and Crossovers being accessible on top of the sub and covered by a solid aluminum plate. There is also a PEQ for the lower frequencies in the 25-30Hz range to help in room correction.

Connections are via RCA and speaker terminals depending on how you are using the sub. It also has inputs and outputs for daisy chaining the subs if you want to really beef up the bass and use more than one sub, the only connection missing is Balanced inputs which may be a problem if long runs are required, although they are available on Descent i sub.

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My connections only require 1M RCA leads. It sits just inside my left speaker, which has always been the best location for all my subs.


Sound for Movies

Recently movies have not played a major part in my listening and viewing sessions, at least not since our daughter was born. Late night viewing is kept to a minimum, but during the day I can let it rip and get the SPL levels up quite a bit.

The usual material I have for demonstrating movies and my systems performance have become quite common because they have excellent mixes and soundtracks. I have become very familiar with them on quite a few systems, although my memory is getting a tad worse as the years fly by.

For demonstration purposes I used War of the Worlds, Minority Report and Flight of the Phoenix. Most of you will know these films fairly well. I suspect you have watched the machines coming out of the ground in War of the Worlds many times over. The Depth i did not disappoint in any way at all, with plenty of slam and movement of air. I was actually not expecting the performance to even come close to my previous sub, but it went very low and with no audible distortion. The volume was around -10db below reference, which was loud enough and very enjoyable.

Minority Report was pretty much the same with plenty of bass in the car factory scene. It pressurized my room quite nicely, with the car seat coming down creating a nice bit of slam and punch to finish off Mr. Cruise (not sure how he escaped that one).

Flight of the Phoenix has an excellent soundtrack in DTS HD MA. The Depth i handled the storm/crash scene with ease and brought justice to the excellent sound mix, keeping me on the edge of my seat. Obviously over the last few months I have watched many films, but the ones demonstrated stand out quite well and separate the men from the boys when it comes to subs. It has delighted me on many soundtracks. With it being so compact it matches my kit extremely well and even my partner said, "Thankfully no more big black boxes". She has given it the seal of approval and it is most certainly staying put.


Sound For Music

This was the most important reason I wanted this sub. I had just purchased some new ProAc D28's and for music they are sublime with a gorgeous mid range and top end, but also with a powerful bottom end. For a 2-way floor stander they surprised me and made me wonder if I really needed a subwoofer at one point. I decided I would look for a sub with the quality of bass that could match the 28's and then some, but most importantly integrate seamlessly, of which the Depth i does with ease.

I have always been the type of person who is against using a subwoofer for 2-channel music and believe in keeping the sound as pure as possible with no sub. I typically use the ProAc's in direct mode from the Arcam AV888. My Arcam processor is the only processor I have came across that plays 2-channel so well and also does movies justice. When partnered with my ProAcs and Martin Logan Depth i, there certainly seems to be a synergy going on with the Depth i complementing my D28's perfectly.

I love all sorts of music with Jazz probably being my favorite. Acoustic Alchemy has made some excellent albums, of which I own them all. Another favorite is Claire Martin with the combo of sub and speakers bringing out the best in their music. I recently purchased the soundtrack to the remake of the TRON film, which is performed by Daft Punk and has some low bass to test your subs abilities.

What I like about the Depth i is that the smaller 8" drive units are very punchy and dynamic, matching the performance of my speakers. The bass is very rich and deep, with a texture to it that lesser subs cannot match. The Depth i easily beats my previous M&K sub for music.


Conclusion

As you can tell this sub is certainly firmly rooted into my system with an excellent sound. It has deep rich bass that will certainly keep any audiophile content. I personally recommend an audition if you are looking for a compact and quality performing subwoofer for your room.

The sub was supplied by Guildford Audio which offered an excellent service and come highly recommended
 
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An excellent review! Those drivers certainly have some serious surrounds. Suggesting very long throw.

I keep wondering whether the increased surface area of an omni-directional source has some magical properties with regards to room and speaker integration. Did you notice anything "special" about the driver layout compared with previous, more conventional subs?

I'm rather curious about one thing: How did you decide which orientation of the three sided enclosure to choose? Did you experiment with this at all? Or did it just seem to look and behave well in a particular "rotation"?

Thanks
 
Cheers Nimby, I just situated down where I have always put my subs in and it has performed well with the Martin Logo facing forwards and the other 2 drivers firing into the walls and it sounds very good indeed in this position, that I have not even considered trying it in a different orientation.

The Integration with my current speakers is seamless and really did not take too much time to dial in, it does have a PEQ built in but that is around the 25hz to 30hz region, but I did not even use that, I suppose if I had all the right tools I could measure its response but unfortunately I do not, but it does play low with the 3 drivers having the same surface area as a 15" sub.
 
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Thanks. I have been harboring a suspicion that radially mounted drivers expand the mutually coupled, driver area. With a single driver the air can leak around the edges of the box far more easily than with a radially mounted series of drivers. The single driver will produce a narrow pressure "cone" which penetrates the air rather than driving it uniformly. The radial arrangement will pump a much enlarged spherical pressure surface. One greater than a single driver of similar total area.

This will also drive the room over a physically larger area than a single cone. The equivalent of a group of subwoofers with (hopefully) reduced room mode excitation. Or possibly the excitation of a greater frequency spread of room modes offering a smoother overall response.

The three driver, 120 degree format has the advantage of damping reaction force vibration without getting too boxy and bulky. It also provides an interesting appearance which gets completely away from the usual cubes.

A win, win, win situation, all round, by the sound of it. ;)

Enjoy! :)
 
Yep certainly Nimby :)

I had the Descent i in my room which had 3x10" drive units and that was quite scary to say the least but also as nimble and as quick as the Depth i, but it was just too big in a way which was more awkward than anything, but if I could of fitted it in I would of probably gone for it, but as it is I am very pleased with the results and it is not outright SPL's that I am after but more to do with the quality of bass as I listen to a lot more music than films now a days, I must be getting old :rolleyes:
 
I'm rather curious about one thing: How did you decide which orientation of the three sided enclosure to choose? Did you experiment with this at all? Or did it just seem to look and behave well in a particular "rotation"?
I placed my Depth i behind and to the left of the left Quad ESL (aesthetic reasons mostly) and found an orientation with one speaker aimed diagonally across the room to blend the best, perhaps because this means no speaker aims directly at the wall / shelfing or corner? I didn't experiment with the placement though (specifically between the speakers), as I didn't want to be yelled at ;).

I didn't buy the Descent i as it was just too large physically :(.
 
Here is a picture of the Depth i in situ which should give you a good idea of the size...

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Hi John,

a brilliant little review there:smashin: i have to say it fits in well with the rest of the furniture/kit, in the second photo especially, even though the focus is on the sub, it doesnt really appear to be drawing any more attention to itself than the other yummy pieces of kit! Im assuming the heritage/dna of the Paradigm subs lies within these original Martin Logan designs... The price is quite decent to for those of whom the sub 1 may not be an option or 6 drivers is a few drivers too many:suicide:

glad to hear its intergrated wonderfully into your setup, I hope you enjoy it for many years to come dude:thumbsup:

Asif
 
Exactly Asif and I see this as the stop gap between what Paradgim offer now, I bet the Sub2 sounds fantastic.
 
How low does this go Recruit? Does it really have the same "slam" factor as your old M&K? - I'm thinking of movies rather than music.
 
How low does this go Recruit? Does it really have the same "slam" factor as your old M&K? - I'm thinking of movies rather than music.

For movies the M&K has the Martin Logan beat for sure there is not as much slam, but it does not do a bad job at all.
I bought this sub more for the music side and that is one area that the Depth i has the M&K beat, I would think the Descent i is a more even match.
 
Exactly Asif and I see this as the stop gap between what Paradgim offer now, I bet the Sub2 sounds fantastic.

Hi John :) i think the Martin Logans may not even have to be deemed stop gaps, im sure both subs will be damn good in there own right. The Sub 2 is something else and other than the ib, there really wasnt anywhere to go from the 5100 which you kindly let me have the first refusal to.

But i'll also add, that although the concept of two+ drivers within a single cabinet can be quite exciting, im also learning through experience that the number of potential problems can multiply to, especially on the newer cutting edge subs. If your sub has 6 drivers-there really are a few headaches in isolating driver issues :suicide:

On occasion, there is something rather attractive about a simple and more basic design:thumbsup:

asif
 
The Martin Logan subs do sound very nice indeed, I had the Descent for a couple of days but it was just to awkward to fit into my location, but the bass was quite loud and low to say the least but the Depth i goes deep and has real quality to it that I have really grown to like and it integrates with my ProAc's perfectly :)
 
Nice review Recruit.

For stereo performance the Martin Logan Descent sub has always been a top performer. I didnt realise that they released the depth.
 
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But i'll also add, that although the concept of two+ drivers within a single cabinet can be quite exciting, im also learning through experience that the number of potential problems can multiply to, especially on the newer cutting edge subs. If your sub has 6 drivers-there really are a few headaches in isolating driver issues :suicide:
Exactly what issues would they be?

Russell
 
Exactly what issues would they be?

Russell

Hii Russell,

reading my post again maybe its a bit poorly worded. I'll try again. Some of the newer sub designs are incorporating more than one driver and some jiggery pokery on the amp plates (eq and otherwise) to get the best performance from the sub. I suppose its straight forward to tell if a driver is blown-my general point is that there is just more to go wrong. I guess this applys to any product/ area where it is aiming to be a market leader/flagship product and is utilising cutting edge technology.

Asif
 
Hello,
Excellent Review. I too own a Depth, but I own the original version. Unlike the Descent, the differences between the "i" Versions of the Depth and Grotto are not that vast.

Whereas the Descent went from a single 400 Watt RMS Amplifier to (3) 250 Watt Amplifiers, the Depth and Grotto went up 50 Watts and other differences were cosmetic and refinement to the Servo Circuit.

As I have been considering adding a additional Depth to my HT, I called MartinLogan and made sure that there would not be an issue with adding a Depth i should I find one in my area as opposed to the Depth. I was told the differences were so slight as not to be a concern. The same cannot be said fir the Descent.

So if any Depth i Owners want to add an additional Depth for a dual subwoofer configuration, it is not a problem to use the original Depth and perhaps save a few quid in the process.
Cheers,
JJ
 
Hi Jack, good to see you over here, the Depth i is a great sub and I am so pleased with my choice thanks to you, it has to be one of the best subs I have listened to music with apart from the Wilson Benesch Torus which is at least twice its price.

As you well know I am at home most of the time apart from my stays in hospital and it certainly helps me pass the time with my music collection which has grown substantially :eek:
 
Hello,
John, I am so glad the Depth i has met your standards. I hope you are enjoying the OPPO BDP-93 that you recently took delivery of as well.
Cheers,
JJ
 
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I would agree that ML is a better name, but Polk is far from low end. I get the feeling the other answers didn't bother to look beyond the name. You are looking at low end ML's and Polk's flagship model.
 
I would agree that ML is a better name, but Polk is far from low end. I get the feeling the other answers didn't bother to look beyond the name. You are looking at low end ML's and Polk's flagship model.

Polk make great products/speakers but never new they did subs as well, the Descent i & Depth i are Martin logans flagship products as there are many different ones below.
 

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