Roland HP702-HP704-LX705-LX706-LX708-GP607-GP609 REVIEW | Page 1

Even the lower price Kawai CA401 ($3099 price) with Grand Feel Compact is at a much lower price than the Roland LX series pianos, the CA401 (and CA501) key action has 12″ long all-wooden white keys as compared to the new shorter Roland keys at just over 10 1/4″ in their more expensive LX706 and LX708  models.

In top name acoustic grand pianos, there is a also a standard “key weight measurement” used by qualified piano technicians to adjust and or set the force needed by the keys to play and move up & down properly. Grand pianos generally have noticeably lighter key actions than most acoustic upright or digital pianos based on our years of experience playing them and those acoustic grand pianos measure approximately 55 grams of down-

weight/static touch-weight force (the amount of finger force needed to start a key moving downward) measured on middle C, although it could be a few grams less or more than that. 

The 55 grams of static down-weight (aka: touch-weight as measured with damper pedal held down) is a fairly standard measurement by many piano technicians and one that is calculated to allow a real grand piano to play at its optimum performance. The up-weight force on a real grand piano (the amount of pressure exerted by the key as it comes back up) is about 1/2 of the down-weight/touch-weight

which is about 27 grams (give or take) of weight and that is something which is fairly standard on good grand pianos. The Roland LX706 Hybrid Grand Keyboard measures at about 59 grams of static down-weight (based on my measurements) which is really good for a digital piano and close to a real grand piano. 

However, the up-weight movement measures at approximately 46 grams (measured at middle C) which gives quite a bit more immediate force being applied by the keys on the Roland LX706 when they are coming back up. In other words, this new key action moves downward very nicely and relatively easily and is well balanced front to back of each key. But the keys come back up much more quickly with noticeably more force than a real grand piano so that part of the key action is not “real” as compared to a larger acoustic grand piano. 

But in reality, in a digital piano this is not a real problem for recreational or even more advanced players because I would rather have the keys come back up quicker and harder than have those keys be sluggish and not respond well coming back up and get in the way of me playing faster, quicker notes. 

The new Roland Grand Keyboard key-action is a very nice and welcome improvement over the lower line PHA50 key action or the much lower priced Standard key action found in the HP702 and the less expensive Roland RP/F/FP digital pianos. By the way, these weight measurements were done personally by me using a key weight measurement device so I was able to see this all for myself.

All models have the imitation ivory-feel and ebony-feel keytops to give a smooth ivory and ebony like finish to the black & white keys which not only looks good, it can also help with absorbing sweat/perspiration from the fingers. I like this proprietary material on the keys and it definitely feels good to the fingers. All key actions in these models have the “escapement” function which tries to simulate the “escapement/let-off” feel that you would get if you were playing a real grand piano and playing the keys very lightly and slowly when feeling a slight hesitation about 1/2 to 3/4 downward in key travel. This can be a useful function and can give you a sense of what key movement can do in

a grand piano in terms of this function…but it’s not absolutely necessary because it’s only
an imitation and definitely not like the real thing. 

The 88-note Roland key action in the HP702 is called the PHA4 “Standard” key-action and it has an all plastic construction with 3 key sensors per key. It is a weighted and graded key action and moves nicely although it’s somewhat firmer to the touch  pressing down the keys, but the keys overall move nicely with good down-weight and up-weight with approx 65 grams of static down-weight and 32 grams of  up-weight based on my measurements using middle C for the measurement. So the “feel” of

the key movement is actually pretty good overall although playing towards the backs of the keys requires more force because the keys are shorter in length. 

This key action is also a a bit noisy when the keys are going down and hitting bottom (creating a “knocking” type of sound) if you are playing harder and more aggressively. It’s more noticeable when your master volume level is lower or you’re using headphones and then all you hear is the key movement noise from the outside. If you are playing more lightly then this is not an issue and you will not hear much noise. But if you put some extra force into playing the keys that’s when you hear the knocking noise…like there is not enough felt to dampen the key action. But overall the Standard key action is playable and works well, but is only in the lower priced HP702 model because that action is less expensive to produce and is actually found in Roland’s low priced FP-30X portable digital piano which sells for $749.

The key action in the next 2 vertical upright models HP704 and LX705 along with the 2 grand piano models called GP607 and GP609 have the better upgraded key action called the PHA50 (still with 3 key sensors per key and the simulated “ivory/ebony” key tops) which I briefly mentioned earlier and it’s built differently and moves differently than the Standard key action. The PHA50 has

added thin wood slats that are adhered to the sides of the white keys so not only does the key look more authentic when they are pushed down (you can see the “wood” material on the sides of the keys when you press a key down), but the extra wood material is supposed to give each key a bit more durability and an acoustic nature to the key itself. 

The PHA50 also has a “stabilizer pin” in the key to keep it aligned so you have less lateral movement and more stability. I do like the PHA50 key action and how it moves although it certainly does not feel like a grand piano but more like an acoustic upright piano because it takes more finger force to press down the keys, especially towards the backs of the keys when you are playing flats and sharps and your fingers are pressed more closely to the backs of the keys. That’s the way it feels on a real upright/vertical acoustic piano. The overall static down-weight on the PHA50 key action in the HP704 and LX705 is approx 62 grams and up-weight force is about 49 grams. 

These weights are approximate based on my personal measurements with these models but should be fairly accurate and do show that it takes more force to press down the keys and there is more force exerted on the fingers when the keys are coming back up then is found on the better Hybrid Grand key action in the LX706 and LX708. But it is an overall enjoyable key action to play and it quite a bit less noisy than the PHA4 Standard all plastic key action.

The LX706 and LX708 have the newer Roland ” Hybrid Grand” keyboard key action (still with 3 key sensors per key and the simulated “ivory/ebony” key tops) but with longer keys in it as I mentioned earlier. The construction of that action is essentially the same as the PHA50 but each key is longer (the part you don’t see located behind the control panel where the visual key ends) so therefore the parts and chassis is extended and modified to fit the

longer keys. As I also mentioned earlier, this new key action is noticeably more realistic than the shorter key PHA50 action, but it is still not like a real grand piano…but it’s getting closer. 

The up-weight force measurement still is much stronger and more forceful than a real grand piano so it’s not exactly like a real acoustic grand. When it comes to Roland digital pianos this new key action is a big

improvement over any other key action Roland currently makes for any Roland digital piano or keyboard product in their lineup, and I like it very much. The Roland “Hybrid Grand” key-action has better balance regardless of where you strike the key and more life-like movement as compared to PHA50.action as I mentioned earlier. So when it comes to the Roland key-actions, it’s the one in the LX706

and LX708 that really shines and mainly because of that extra nearly 1 1/2″ in extra length over the PHA50 key action. 

It’s interesting to note that the Roland 3′ deep GP607 and 5′ deep GP609 digital baby grands use the PHA50 key action and not the new Hybrid Grand key-action. This is because the GP607 and GP609 came out on the market long before the new LX706 and LX708 were introduced. So in reality the LX706 and LX708 have the more authentic key action as compared to the GP607 and GP609 grand style digital pianos. This is certainly not a bad thing to have slightly short keys in the Grand piano models because those 2 digital grand pianos are very enjoyable to play and people who purchase those pianos like the playability of those 2 models overall. 

But…there is no doubt that the new Grand key actions are better and more authentic than the PHA50 key actions. Roland just came out with the new replacement of the GP609 grand and that replacement is called the GP9 digital grand piano. This model now has the Grand Hybrid key action with the longer keys, so that is a nice upgrade over the now discontinued GP609.

Another unique feature worth mentioning which is part of the key action response in the LX708 and the new GP9 digital grand, is called “Haptic key vibrations.” This feature electronically creates a physical vibration sensation within each physical key of the piano to give the player a sense of “organic vibrations” that you may otherwise feel in a real acoustic piano when playing it. If don’t have experience playing a real good quality acoustic upright or grand piano then you would likely not be aware that you can feel a sensation of subtle vibrations coming through the piano keys when playing the piano at a louder volume on an acoustic piano. The

majority of digital pianos cannot do this so when comparing many digital pianos to each other you may not care whether that “key vibrating feature” exists or not because you won’t miss what you don’t know about.  

It also depends on how sensitive you are to those kinds of physical vibrations that resonating into the keys of a real piano when playing it a full volume. Since the Roland key action keys are mostly plastic and the piano sound comes through speakers

rather than naturally resonating through a wood acoustic cabinet (the Roland pianos and other brands of digital pianos are not made of solid core wood like real pianos are), then the “electronically produced” Haptic vibrations would add a sense of natural realism within the keys when you are playing them and those vibrations can be adjusted to be more or less noticeable if you choose to use them. I will say from personal experience that it is true that you can feel subtle natural vibrations coming into your fingers when you are playing a real acoustic piano and that is something that does not happen in most digital pianos. So with this Haptic vibration feature in the LX708 and GP9, Roland has added a nice touch of physical realism to the piano playing experience that no other Roland piano has and no other brand has in this price range.

The piano sound in the Roland home pianos is unique as compared to other brands in that these Roland pianos use “Physical Modeling” technology. In the previous Roland models called HP603, HP605, LX7, and LX17, Roland used this same technology which means the piano sounds are developed using mathematical algorithms which try to “simulate” a real grand piano sound by analyzing what acoustic pianos actually do in terms of the acoustic piano sound and how it resonates with organic overtones,

vibrations, natural dynamic tones, sympathetic string vibrations, and soundboard vibrations. 

All of this is coupled with sustained and unsustained tones and then this technology tries to do that with every one of the 88 keys along with a variety of other tonal real-time measurements…all in virtual reality in real-time as you play. 

In other words, the Roland piano sounds are not “recorded” with microphones from a real piano like other brands are…the piano sounds are “virtual” and use technology that (tries to) “model” the

real grand piano sound. Roland obviously believes this technology is the way to go and thinks it’s a better way to reproduce the acoustic grand piano sound as opposed to sampling (aka: recording) a real live grand piano using microphones to capture the original sound. Up until now the sampling technology has been the way that all digital pianos have captured the piano sound and then digitized that sound into a circuit board with digital chips and then that sound

comes out when playing the keys on a digital piano. 

The sampling process can be expensive if done correctly but some piano sound samples are done cheaply (to save money) like the off-brands do and the results show how bad some of these off-brand digital pianos can be when it comes to reproducing an actual grand piano sound…or any acoustic piano sound for that matter. Also, the recorded sampling technology does have its limitations on producing a complete organic piano sound, so neither technology by itself is perfect. Just so you know, the physical modeling piano

sound technology does not extend to the non-piano instrument sounds of the Roland pianos. 

All of those sounds are done by sampling on the Roland pianos as well as the other brands. There is also a “combined” technology being utilized these days by Kawai, Dexibell, and a little bit by Yamaha which is a combination of sampling & physical modeling which starts out with a real recorded samples of a real acoustic grand pianos and then they use physical modeling to enhance the sampled sound and “fill in the cracks” so to speak to include additional organic tonal elements that sampling may not have been able to do as well. This level of piano sound technology can be more authentic than just pure sound sampling technology alone if done correctly, and the Kawai and also the Dexibell digital piano companies are doing an impressive job in my opinion using this combined technology for an even more authentic piano sound reproduction. 

Personally I have listened to enough of these different pianos to know that if there is not a least some or all of the piano sound originally recorded from the “real thing” then the over-all physical modelled piano tone alone can sound over-processed, artificial, and saturated.

There is also something called “polyphony” which is a feature specification in all digital pianos. The polyphony number is usually described as how many piano notes/keys can be played at one time with out notes “dropping out” abruptly while keys are being played. In other words polyphony really is another word for memory and that memory needs to be sufficient for the piano&

instrument sounds to be able to be played and heard without any of the notes disappearing and dropping out because you have run out of polyphony memory. The top polyphony number these days for “sampled” piano and instrument sounds is 256-notes of polyphony as measured in mono tones. Many instrument and piano sounds are recorded in stereo for the best sound reproduction and a stereo sound takes 2 notes of polyphony memory as opposed to 1 note of

polyphony memory in mono recording. 

That means in a digital piano with 256 notes of polyphony memory actually produces 128 notes of polyphony when playing a stereo instrument sound. Physical modeling is only applied to the piano sounds and because of this technology the polyphony memory is “unlimited” and does not have a specific limitation by a number. With these Roland pianos the piano sounds themselves have “unlimited polyphony memory” and the non-piano instrument sounds have either 384

notes of polyphony or 256 notes of polyphony depending on the model. It’s interesting to note that the top 3 new vertical LX705, 706, and 708 have 256 notes of polyphony while the other models including the lowest price HP702 have the 384-note polyphony memory chip. 

In my opinion this is likely due to the new LX pianos offering a new and improved physical modeling piano sound technology which may require more memory and therefore apparently limits the non-piano instrument sound polyphony to 256 notes instead of 384 notes in the other models. However, regardless of the reasons, 256 notes of polyphony is more than enough polyphony memory for instrument sounds because you still have unlimited polyphony for the piano sounds and even that is not absolutely necessary. Also, I personally have not had any playing issues when the acoustic piano tones in digital pianos are 256-note polyphony. A by-product of physical modelling is unlimited polyphony but that does not mean you cannot be completely happy with digital pianos that have piano sounds with 256-note polyphony because that number is still a lot!

After playing this new line of Roland digital pianos for a number of hours I can say that, in my opinion, it is unfortunately a “mixed bag” when it comes to the piano sound and how “real” it is. It is an interesting mixed “bag” because the new model HP702 & HP704 have the same piano sound chip as the previous discontinued HP models HP603 & HP605 as I mentioned earlier as well as the top current Roland digital grand models GP607 and GP609 having that same piano sound chip. In other words if you played the new HP702, HP704, GP607, and GP609, they would all sound exactly the same…even the key actions are the the same with the exception of the new HP701 which has the more basic standard key action. The biggest differences among all those models is really the cabinet designs & sizes and the built-in speaker systems. When you look at the new LX series including the LX705, LX706, and LX708, those three models have a new “upgraded” piano sound chip which the other Roland pianos do not have. 

Although each Roland model in the entire HP, LX, and GP digital piano line have 4 grand piano tones, the 4 tones in the LX series are noticeably different than the other models and for me those sounds were disappointing. In fact, I was surprised at how disappointing those piano sounds were on the LX series because all three models had the same disappointing tone. 

Also, even though the LX706, and LX708 had the upgraded, more powerful speakers internal speaker systems, especially the LX708, it really did not make a difference in the artificial tone coming out of them…they were all equal to my ears in that way.

When I play a digital piano for the first time, I don’t try to use any “tricks” or change any editing parameters to try and make the piano sound better or different…I just want to see how the piano sounds when you first power it on…just playing it as a piano with the default settings. The manufacturer should put their “best foot forward” and have their best pianos at their optimal best as soon as you turn the piano on and play it…just like it would be on a real grand piano…you play it and what you hear is was you get. However, with the new LX pianos, I did not like those piano sounds and much preferred the other piano sound chip in the lower priced HP pianos and the GP grand pianos. When I played the LX705, LX707, and LX708 piano sounds recently side by side, the best way for me to describe them is “muffled, mid-rangy, saturated (not much noticeable individual hammer attack or clarity…mostly saturated tone bouncing around), artificial with some individual plunky notes,

and thinner in the overall tone.” 

This was true for the 1st piano sound in the LX models which they call the European piano sound #1 but that piano sound was the best of the 4 piano tones and had the “fullest tone.” The next piano sound is called American #1 and it too had a “thinner, mid-range (not much treble or bass) piano sound that sounded a bit saturated (not well defined) and some of the notes were also plunky staccato sounding notes like they had a something in the sound that made it have a thud sort of tone on the initial attack…very artificial. The next two piano sounds are variations of the first two pianos with the next piano sound being called

European #2 and that one was even more artificial in tone sounding somewhat brassy and thin. Finally, the 4th piano sound is called American #2 and that sound was by far, at least to my ears, the most unrealistic and undesirable of the 4 physical modeled piano sounds because it was incredibly twangy and brassy, not usable at all as far as I am concerned. 

Whether I was playing the LX705, LX706, or LX708, the sound was pretty much the same with the exception of the LX708 which has the better, more powerful internal speaker system which produces a bigger, bassier tone and that helped the sound somewhat…but mostly it was a similar experience as compared to the lesser models. Playing these 4 piano sounds from the LX series through a good pair of stereo headphones did make a noticeable and unexpected positive difference and although it was better through the headphones, it still had a very artificial flavor to the piano sounds, at least to my ears, and I listen to and play different acoustic & digital pianos all the time.

Another issue with the LX series that I immediately noticed when playing them is that there was, in my opinion, a “stretched tuning” problem which was especially evident to me with the 2 “American” piano sounds which made some note intervals sound noticeably “out of tune” with each other. In other words, there are certain note intervals and the relationship between them (which I use often) especially when playing chords, where the “stretched tuning” process that Roland uses when setting up the original tuning on these pianos is way out of normal stretch tuning range, in my opinion and to my ears. Although stretched tuning method is what good tuners use to set a piano tuning in a real acoustic piano and it varies depending on the size of the piano, it

sounds like Roland “over-stretched” the tuning for the LX series and the result is notes (when played together) grate on your ears…at least they do with me, and I have talked about this issue with other Roland models before such as the low price FP-30X piano (which had no relative tuning adjustments) and other models which use that particular sound chip. 

However, what is interesting is when Roland developed their previous other physical modeling chip that is in the HP702, HP704, GP607, and GP609 (as well as their 2 new digital grands GP6 and GP9), there are no obvious stretched tuning issues that I heard based on my extended experience playing those models. In other words, the HP & GP models have good

stretch tuning and it sounds natural and within reason and the same was true for the previous HP and LX models which are now discontinued. But with the new LX models, the stretched tuning issue has returned and is very troubling to players like me who play specific intervals often where the “out of tune” issue is most noticeable. I am not saying the entire piano is out of tune because it is not. However, in the “Piano Designer Mode” there is a function called “single note tuning” which allows you to digitally adjust any of the 88 notes slightly up or down in tuning using the piano controls or within the Piano Designer app. 

This can potentially

resolve the issue but only if you are good at tuning individual notes and specific notes within specific intervals. If you have a really good “ear” like mine or have piano tuning training, then maybe you

can adjust the tuning between notes in a way that resolves the stretch tuning issue…but for most people I believe this will be a very challenging task. On older Roland piano models like HP506 and HP508 as examples, Roland used to include specific functions for quickly adjusting the “stretch tuning” mode with a couple preset modes and an “off mode” to quickly turn it off which helped a number of people who were sensitive. In the current models of LX series I did not find specific controls designed to quickly deal with the poor stretched tuning that I experienced on these models. If those control features are there then I sure did not see it. Many people may not notice this “out-of-tune” issue at all when playing these Roland pianos but I did but have not noticed these same issues on other current brand of digital pianos from Yamaha, Kawai, Casio, Korg, etc…but just on Roland LX models with this new piano sound chip but not on the HP and GP models. 

Again, the other physical modeling sound chip in the HP702, HP704, GP607, and GP609 (and the new GP6 and GP9) do not have any of these issues that I pointed out in the LX models. Maybe all of the LX models I recently played were “mis-adjusted” but I do not think that was the case as this issue was on all of them on default piano sounds. For this reason alone I would not personally purchase an LX model because good default tuning is important to me and ultimately I am looking to put another good digital piano into my music studio but unfortunately would not consider an LX model at this point.

Just so you know, I am a big fan of Roland music products and have been for many years. I have used them professionally and in my home studio so I like them and have high expectations of them. That’s why when I see and hear stuff that is a negative issue for me, especially on these digital pianos, it disappoints me that Roland did not do a better job given their abilities in the

electronic music products world. Unfortunately another continued issue for me with the physical modeling technology in these pianos that was an issue in the previous models is the fact that when you change from one piano sound setting to another, whether they be single piano tones or layered with another instrument sound, when you make that change while playing a song such as going from one movement of the song to another, or from verse to chorus as an example, and you want a new piano sound setting in that part of the

song, when you change from one sound to next when pressing the sound button, the entire note(s) that you have just played and are sustaining will just cut out and stop playing in mid-stream. 

In other words, there is no smooth sound transition when playing notes and changing sounds…everything just shuts off until you play the notes again. This inability to transition from one piano sound setting to the next does not exist in most of the other major brands (especially in this higher price range) including Kawai, Yamaha, Casio, Dexibell, etc and a few of those

brands also use physical modeling technology although it is different in the other brands. In past models prior to the current Roland physical modeling technology, Roland never had this lack of “smooth transition” from one sound to the next but when they developed this newer physical modeling piano sound technology, that when this issue first began and is still there even in these latest models. 

This “all notes off” issue is particularly irritating if you happen to be playing in some

performance at an event or at home, church, school, and you want to change those sounds at different times in different parts of your song. You just cannot do it smoothly without this “all notes off” situation occurring. If this issue was simply a common “glitch,” then it likely could be resolved, repaired, or updated with new software. But Roland has yet to make any changes to the way the piano sounds transition from one to the next so it’s my guess they cannot do it because of the limitations of their technology…and that’s too bad…at least for piano players like me who don’t just want to use 1 sound setting for the entire song the entire time. I personally like to make piano sound setting changes during the song sometimes and have that change be seamless with a smooth transition. But unfortunately on these Roland pianos, this type of thing cannot be done and again, this limitation on all of the Roland models would be a deal-breaker for me, but I am quite picky in that way in being able to transition to different instrument sound settings while playing a song.

-Please click on this link to continue with this Roland Piano Review on Page 2

If you want more info on new digital pianos and LOWER PRICES than internet discounts, please email me at tim@azpianowholesale.com or call direct at 602-571-1864.