Yamaha RX-V2400 A/V Receiver Review

I was pleased to find no impedance selector switch on the back panel common to all Yamaha A/V receivers I have seen in the past. However, my satisfaction quickly diminished when in revealed itself in the user menus.

I recommend the "Minimum 8 ohms" setting even for 4 ohm speakers of moderate efficiency ( > 89dB SPL). Yamaha includes a" 6 ohm" setting to satisfy UL as well as easing consumer concerns about driving low impedance loads. These switches step down voltage feed to the power sections which can limit dynamics and overall fidelity. My advice is to keep the switch set to "Minimum 8 ohms" regardless of the impedance of your speakers and ensure proper ventilation of the Receiver. 

I initially engaged the YPAO with the "Flat" setting to equalize all of the speakers in my set-up.

It was interesting to see how the YPAO altered the frequency response of even the similar speakers in my set-up, making one realize just how much of a profound impact the room acoustics have on a speakers sonic signature. It almost makes you wonder if using identical speakers for all channels for alleged perfect timber matching is really as critical as acclaimed giving how the room acoustics drastically affects speaker performance rendering identical speakers positioned at different locations to not sound so identical.

• Q Factor: 05 to 10.1
• Gain: -20 to +6dB (0.5dB steps)
• Frequency: 63Hz to 16kHz (1/3 octave)
  

If you consider the basic relationship of sound and propagation through air given the following formula:

(where v = velocity (speed of sound =1140 ft/s STP and f = frequency (Hz) ) then we see the wavelength of sound for 63Hz = 18 ft and for 16kHz = .86 inches!

Thus altering high frequency room response will affect only a very small listening area above a couple of hundred Hertz. High frequency harmonics are generally close together, if not overlapping, and their corresponding intensities are far less than the fundamental, making them more dependent on listening position. Another issue to consider with high frequency room correction is that the measuring microphone cannot accurately measure direct to reflected sound. The goal of room correction is to correct for room anomalies, not the loudspeakers (assuming the loudspeakers are of sound design). Altering the frequency response of the loudspeakers in this fashion changes the direct sound to compensate for a deficiency in the ambient or reflected sound field caused by the room. This may in fact alter the direct to reflected sound at the listening position further deteriorating imaging of the loudspeaker and corrupting the critical first arrival of sound. Ideally active room correction would best be applied at frequencies below 200Hz where sound is more difficult for the listener to localize. Utilizing a more precise parametric equalizer may be applied to analyze room modes to construct notch filters to reduce the excessive room decay times (RT60- # of milliseconds it takes for a sound to decay by 60dB).

Alternatively, a point to consider is that some room correction systems actually do address speaker non-linearities as well as room interaction affects. The problem is that most systems are not able to distinguish between the non-linearities of the speaker versus the non-linearities induced by the room. In some cases in may not really matter. For instance, in the bass frequencies smoothing out the response may involve changing phase and gain at certain frequencies. As long as the correction is made for the listening position we probably don't care how much of the problem is speaker or room related. For that matter, I can understand why the Yamaha YPAO system does not attempt correction at very low frequencies. It would take much more reserve power than the receiver is capable of delivering. In this respect limiting the correction to a moderately low frequency is understandable and in fact quite necessary. Of course that doesn't change the fact that we would all like compensation down to the very lowest frequencies. Practically speaking Yamaha could NOT put a correction filter on the LFE output because the power necessary for correction would way overtax most subwoofers (amplifier and driver excursion). It may however behoove Yamaha to introduce their own active servo subwoofer integrating low frequency room correction with a system much like many of Velodyne's latest product offerings. A system that initially measures nearfield power response of the speaker as well as impulse response and then takes into consideration a measurement which shows room decay time would probably make for an even more accurate correction system. Now if only a manufacturer would build such a system affordably!

The level check was the last auto test set-up feature that the RX-V2400 performed. This test absolutely required a quite room to properly perform. My ceiling fan actually caused it to give me an error message "Noisy".

After the level checker was complete, I measured each channel level using both the Yamaha internal test tones and my trusty Avia disc. I found the worst case channel balance differences between channels to be about 1.5dB off and confirmed this with both test tone suites. The good news here is that the auto set-up did configure a reasonably accurate channel balance between channels automatically, and that the internal test tones in the receiver were accurate. The not so good news is I had to manually tweak each channel trim for greater accuracy.

It's interesting to note that maxing the master volume level (+9.0dB) doesn't fill the bar completely. This is due to range limiting if any of the channel trims are set beyond 0dB. When I returned all of the channel trims to default 0dB, the master volume level maxed out at +13dB.

However, since most receivers and processors don't yet incorporate auto level calibration, I would normally have had to do this anyway, so to me it's no deal breaker. I believe the level discrepancies may have been a result of the auto level checker using short tone bursts as opposed to continuous pink noise traditionally used when manually calibrating a system using an SPL meter. The tone bursts in the auto level set-up may emphasize the direct sound from the speakers while the pink noise in manual configuration may be interpreting the ambient sound field in the room. Ideally, they'd both should be the same but that's seldom the case with real rooms and real speakers. However, given the peaky and sometime steady state in sound, I would probably choose the latter for the most accurate speaker level calibration.

The RX-V2400 refreshingly had 0.5dB trim adjustments for all channels which is still uncommon in many higher priced processors. As a side note, we have found some receivers / processors and DVD players internal test tones to be somewhat out of whack, especially when calibrating at different reference levels. The Yamaha test tones, however, identically tracked Avia's when the master volume levels were set to produce the same reference levels. In addition, I achieved accurate channel trim balances for all reference levels I tested during the set-up phase. This didn't surprise me since I have consistently found Yamaha receivers to have incredibly accurate test tones and channel tracking.

What good is a feature packed receiver or any A/V gear for that matter if it cannot deliver the goods in sonic performance? Our viewpoint is sound first, features second. With that here is my subjective impression of the RX-V2400 for the gamut of playback modes I put it through.

With all DSP processing and room correction features turned off ( " Pure Direct " Mode), I began my two channel critical listening tests on my reference mini monitor Status Acoustics Decimo's in my bedroom system. The Decimo's are an 8 ohm, moderately efficient load and don't require gobs of power to shine, just quality clean power. Here is where the RX-V2400 really delivered quite admirably. The noise floor (especially in "Pure Direct" mode) was commendably low (published spec of 100dBA, 250mV reference translates to over 112dB @ 1V), comparable to what I recalled from the venerable RX-V1 and RX-Z1 flagship Yamaha receivers. The DAC section in the RX-V2400 was top notch. In fact, switching back and forth between using my bedroom SACD changer DAC's for CD playback vs the internal DAC's in the RX-V2400, I preferred the latter. When the RX-V2400 served as the DAC, it sounded more open, and detailed in the high frequencies. The amp section proved to be quite dynamic, more so then my Harman Kardon integrated amplifier that currently comprises my bedroom system. I felt that RX-V2400 again had a more open and punchy presence than my integrated amp, but was a bit more analytical sounding. I definitely felt that this was the best sounding sub $1000 receiver I have yet to hear Yamaha produce. My old RXV-992 always seemed (dare I say) "bright" sounding with my speakers, and it wasn't until my eventual upgrade to the DSP-A1 that things smoothed out considerably. With the RX-V2400, I didn't feel like two channel playback was bright or stringent in this set-up. In fact, I threw a pair of Dynaudios and Von Schweikert bookshelf speakers at it and was constantly pleased by how the Yammie was delivering the sonic goods with no signs of distress or pungent sound character.

I was curious to see how the YPAO function would alter the sonic signature of my beloved Decimo's so I placed the mic at my primary listening position and let the RX-V2400 send out its series of sonar sounding bat signals to optimize the system. With the YPAO feature engaged (flat setting), my speakers had a definitively more forward tonal quality, especially in the midrange and highs and sounded louder and more dynamic upon first listening. However, over time switching back and forth, I found the YPAO seemed to focus the soundstage into a more delineated sweet spot, but at the sacrifice of imaging. My speakers no longer seemed to have their infamous disappearing sound characteristic. Instead, they sounded a bit boxier and closed in. This was particularly more noticeable on analog inputs that now had to undergo and extra A/D and D/A conversion to incorporate the DSP processing of the YPAO feature. I also gave the YPAO a crack at the Dynaudio's I currently have in my listening room. In this case, the YPAO dulled the sound of these already sonically warm speakers. Again, I preferred no room correction for these speakers. The reader must be cautioned however, that the sonic attributes noticed here were founded on speaker systems of incredibly high resolution that in a decently controlled acoustical environment really didn't require any room correction whatsoever. Some may actually prefer how the YPAO system alters their speaker systems response, especially if there are inherent deficiencies in the design and corresponding performance. Though I preferred no YPAO setting over defeat, I repeated the YPAO calibration for the other offerings (IE. Low, Mid, High) and found the best blend was achieved in the original "Flat" setting for my Decimo's and the High setting for the Dynaudio's. I recommend determining how YPAO works in your system before ruling it out as a viable option for room correction or speaker performance compensation.

For kicks I wanted to see how the RX-V2400 would perform in my living room when connected to my larger, moderately efficient 4 ohm (89dB SPL 1 watt/meter) reference speakers. It is unlikely that an end user would mate a pair of $5500 speakers with a $1000 receiver, but I figured what the heck, might as well try it. Again, I was mightily impressed with how the RX-V2400 handled itself. Though it wasn't quite as smooth or refined sounding as what I was accustomed to in a $4K+ receiver or dedicated amplifier, it certainly was no slouch by any means. If one were to use this receiver in a very high performance playback set-up with inefficient speakers in a moderately large sized living room, I would encourage preamp outing at least the front three channels to a dedicated monster sized amp. This will help reserve the power supply and amplifiers added headroom to better power the back and surround channels.

I was also pleasantly surprised to find that Yamaha reserved independent level controls via its EXT inputs, a feature not common even to many costlier separate pre/pro's. Having independent level settings for DVD-A and SACD is vital due to inherent format differences, especially for the subwoofer output which could be 10-15dB lower in SACD / DVD-A than DD /DTS in some players for example.

The percussion's in this track surrounded very three dimensional and lifelike making me long for more of what this disc had to offer. TracK#5 " Come Away With Me" put me right where I needed to be with the very airy and smooth brushes of the cymbals and melodic relaxing, crystal clear vocals from Norah Jones. Track#9 " I've Got To See You Again " surrounded me with Norah's powerful vocal ballads urging me to crank the volume even higher because it just sounded so good. By now it was clear to me that the RX-V2400 was handling high resolution formats exemplary demonstrating that noise floor and distortion were not limiting factors of reproducing the musical nature of this format as I have heard in some lower priced receivers and moderately prices pre/pros.

Playing the wonderfully recorded multi channel DVD-A Graham Nash "Songs for the Survivors" gave the RX-V2400 quite a work out. After about five minutes of blasting this disc, I muted the volume and noted the RX-V2400 cooling fan was engaged and the receiver was warm to the touch. I strongly encourage users to allow for good top and back ventilation for this receiver if you plan on playing it at high sustained volume levels in medium to large sized rooms with moderately efficient speakers ( < 89dB SPL @1meter). Don't panic, the fan was very quite and only audibly noticeable when I turned down the volume and stood within a few feet from the receiver. When playing at these sustained volume levels I noted the RX-V2400 maintained good composure, but took on a slightly forward tonal nature in the midrange with a bit of edginess in the highs. However, I don't know of any receiver at the $1000 price point that would fair better under such circumstances. At slightly less than insane listening levels, the RX-V2400 always sounded well focused, and fluid. At low volume levels, all resolution was preserved, as I have been accustomed too on my reference system.

As I have noted in previous Yamaha receivers, home theater is truly where their RXV series excel. Yamaha has always been unequalled in their DSP processing to enhance the movie watching experience and the RX-V2400 proved to be no exception. While I found the DSP modes to be too numerous and over emphasizing in most applications, I did manage to find a few favorites and tweak them to more subtle settings that worked better in my system. I was happy to see Yamaha include their proprietary dedicated front effects channels, or in their new nomenclature "Presence" channels. However, if you opt for back channels, you are left with no "Presence" channels. I would have liked to see Yamaha offer the ability to preamp out say the front channels, and reroute those unused channels to the "Presence" channels for a full blown 9.1 channel playback system. This would be the ultimate solution for the audiophile who desires a dedicated external power amp for their main channels, but wants the ability for a 9.1 speaker configuration, basically allowing them to have their cake and eat it too. However, I suppose Yamaha is reserving this speaker configuration for their forthcoming RX-Z9 flagship receiver.

Most of my home theater evaluation of the RX-V2400 was done in the traditional 7.1 configuration (back surrounds, no presence channels). I started with the discrete DTS ES DVD of Gladiator. The opening scenes of this movie are both visually and audibly impressive. I really did enjoy having the back channels in this instance and felt it did expand the surround field and smooth out panning between channels. Switching between THX and Yamaha DSP cinema modes, I preferred the latter. The THX mode in my setup did seem to expand the rear soundfield, but at the expense of dulling out the front channels, most likely do to the REQ feature of THX. However, some listeners may prefer this in their set-ups so by all means choose what is right for you.

I found the better DSP modes in my set-up were "Spectacle and Adventure". I have always been a fan of the "Adventure" mode, but only after toning down some of the parameters. To me this soundfield really does enhance the movie watching experience, especially if you can take advantage of the dedicated front effects channels.

The RX-V2400 didn't disappoint. The bloodbath battle scenes were well conveyed with all the sense of detail and conviction I was accustomed too, only this time I had a little DSP enhancement to make things sound a bit BIGGER in scope that ordinary processing.

For the record, there are only two instances when I prefer a Yamaha DSP mode over conventional processing (ie. DD /DTS, DPLII,DTS Neo,etc):

Other than that, I usually stick to the regulars, especially DPLII for older music CD's.

This is a long laundry list, and certainly not meant to suggest the RX-V2400 is lacking for its price point.

It may seem that I am being overly critical of this receiver to some readers, but please understand I do this to set a precedent for manufacturers future product advancements. The Yamaha RX-V2400 is an extraordinarily good product and value, and in my opinion, fills a marketplace that no other product in its price class currently does. It offers a quick auto set-up for the neophyte that will at least achieve a reasonably good sounding configuration some users ordinarily wouldn't be able to achieve manually, and allows for user tweakable adjustments to improve those settings. It even has a bi-directional RS-232 interface and a receiver editor feature allowing the user, or more commonly, the custom installer to set-up, configure, and retain programmable settings on a computer incase of the event of memory failure or accidental user erasure/modification of settings. Two multi zone settings (one with power amp assignability, the other passive with triggered outputs) allows for the receiver to serve as the demarcation point for house wide entertainment with minimal components required.

If you go one step further and abandon the internal amp sections for the five main channels in favor of a dedicated multi channel amp, you are left with a pre/pro that rivals many costlier dedicated pre/pros in performance and function with amps to power the proprietary DSP modes in a traditional 5.1 set-up, or to power multi room / multi source applications. Any way you look at it, the Yamaha RX-V2400 is a terrific bargain and a definite trendsetter for receiver manufacturers to follow suit.