P-51 Mustang vs. SR-71A Blackbird Comparison Part One and Two (and a Bonus!)
After a battery of testing, I have come to the conclusion that this comparison needs to be in two parts. The first is using high gain settings with the AKG K702 headphone (with a Stephan Audio Arts replacement cable and 250+ hours burn-in). Part two will be with Denon AH-D2000 cans at medium gain settings.
OK, the contenders: In this corner, the RSA SR-71A Blackbird with over 200 hours of burn-in and using i-power 500 mAH Li-Ion batteries. In the other corner, the RSA P-51 Mustang with over 100 hours of burn-in and the internal battery.
This is to be an apples to apples comparison using the same music, sound source and cable. The sound sources are the Cowon O2 and Archos 7 IMT. I used a Cable Pro Panorama interconnect. And of course the K702 cans which, while not considered high impedance at 62 ohms, still requires a lot of power to drive. The cans are full range but don't really push bass frequencies without encouragement. However to be fair, I set the EQ on both players at +3dB above zero on all freq bands (while maintaining a flat level), so as not to unduly influence the sound.
I used the following tracks played on the Cowon O2, alternating back and forth between the amps:
AC/DC "Thunderstruck" (m4a)
Blue Oyster Cult "Godzilla" (m4a)
Dire Straits "Sultans of Swing" (m4a)
Donna Summer "I Feel Love" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Emiliana Torrini "Gollum's Song" (FLAC)
Howard Shore/Annie Lennox "Into the West" (FLAC)
Howard Shore "Shelob's Lair" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
For video, I played the first ten minutes of the following on the Archos 7:
Cowboy Bebop the Movie
Serenity
Cars
Ironman
In setting a comfortable listening level, I found the Mustang and the Blackbird sounded the same with the Mustang volume at 12 o'clock and the Blackbird set at 2 o'clock. I don't know if that means the Mustang puts out more power or if the Blackbird's volume is more conservative. Maybe, it is just the unique characteristics of the amps.
Lastly, I am by no means a professional reviewer. I will report the impressions the amps give me, but your experience or ability to characterize the sounds may vary. I simply want to offer my opinions and hope they brook some discussion. If you want me to clarify or restate my observation, let me know and I will try my best.
Observations with AKG K702 cans, amps at high gain:
AC/DC - "Thunderstruck":
Mustang - Mids and Highs are prominent. Bass is tight but rather subdued.
Blackbird - Wider soundstage but sounds a little distant. A warmer sound with a little more bass presence. Mids and highs are a bit subdued, but provide a more well rounded sound.
Blue Oyster Cult - "Godzilla":
Mustang - Gravitates toward high end with a slight bass presence. Sounds a bit "tinny"
Blackbird - Punched me in the ear with the first notes. Much warmer overall with less emphasis on high end.
Dire Straits "Sultans of Swing":
Mustang - Very analytical with a good level of bass and treble. Mids especially stand out. Bass isn't pounding, but a slightly better presence than previous tracks.
Blackbird - Warmer sound; not so analytical. Doesn't sound that different than the Mustang but it does make you feel a little more "into" the music.
Donna Summer "I Feel Love":
Mustang - Analytical with a hint of bass. Seemed like the low end was on the extreme edges of the soundstage (possibly due to my encoding).
Blackbird - Smaller soundstage, but the sound is more evenly spread out; possibly contributing to the warmth of the sound.
Eagles "Hotel California":
Mustang - The intro was outstanding; very detailed. I could easily make out every pluck of the strings. While the bass sometimes rises to the occasion, it is subdued for the most part.
Blackbird - Intro sounded muddier, more subdued. Overall the sound was well rounded with a good (but not overwhelming) bass presence.
Howard Shore/Emiliana Torrini "Gollum's Song":
Mustang - A beautiful, full-range sound with a good bass presence and very prominent mids. The violins accompanying Emiliana were very notable along with her haunting voice.
Blackbird - Rather muddy in all ranges. The high end sounded "veiled".
Howard Shore/Annie Lennox "Into the West":
Mustang - Very nice, well-rounded sound. Has more low-end presence with less emphasis on the high-end.
Blackbird - Warm but muddy low end with very little detail overall. The lower mid-range seemed overemphasized, almost overwhelming the rest of the music.
Howard Shore "Shelob's Lair":
Mustang - Surprisingly not as shrill or detailed in the high-end as I anticipated. While the bass was good and tight, the overall sound didn't really "wow" me.
Blackbird - Warmer and more subdued than the P-51 but with an overall better sound. The highs still seem "veiled". If I want to feel the "dread" of the passage, this amp conveys it better.
The Moody Blues "The Day Begins":
Mustang - Very detailed with a sweet spot in the upper mid range and the highs. The low notes are there but not prominent.
Blackbird - Warm with the sweet spot in the lower mid range. The high end isn't veiled either. the amp seems more suited for this piece of music. Excellent soundstage.
Cowboy Bebop the Movie (English dub):
Mustang - Very detailed; I could even hear the background music in the store. Spikes voice has good presence. The bass is there but not subwoofer quality (not punchy).
Blackbird - The soundstage wasn't very big. Nothing was really emphasized or stood out. Actually rather..."eh".
Serenity:
Mustang - Detailed with tight, but not punchy, bass.
Blackbird - Stronger bass with less detail in the highs. The warmth contributes to the movie, making it more enjoyable.
Cars:
Mustang - Where's the bass? Detailed mids and highs.
Blackbird - Warm, well rounded sound. Pleasant to listen to.
Ironman:
Mustang - Bass lacks punch.
Blackbird - More prominent bass with surprising detail in the high-end (especially gunfire).
Summary:
I have to agree with other reviewers that these amps have different sounds. You must realize that I usually adjust the EQ or DSP settings on my players to suit the sound. I rarely keep my EQ flat, emphasizing the treble and bass to push the sound to the headphones. Since the K702 isn't known for being bass-heavy, I tend to compensate a bit. But I really can't chose one amp above the other; so I'll keep both
. I will just have the right niche for each of them.
Apples to apples - I think if you want to listen to the music itself, go with the Mustang. If you want the music to carry you away, the warmth of the Blackbird stands out. Kind of a letter-of-the-law vs. the spirit-of-the-law difference. For movies, I find the Mustang tends to edge out the Blackbird, with Irondude(man) being the exception.
These results are for one set of cans. As I have found, the so-called "missing bass" of the Mustang is there, you just have the right cans to appreciate it.
Next installment...
A comparison using the Denon AH-D2000 headphones.
Part Two
...and here...we...GO!
Same test as before but this time the amps are set to mid gain and I am using the Denon AH-D2000 with 50+ hours of burn-in.
I used the same tracks on the Cowon O2, alternating back and forth between the amps:
AC/DC "Thunderstruck" (m4a)
Blue Oyster Cult "Godzilla" (m4a)
Dire Straits "Sultans of Swing" (m4a)
Donna Summer "I Feel Love" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Emiliana Torrini "Gollum's Song" (FLAC)
Howard Shore/Annie Lennox "Into the West" (FLAC)
Howard Shore "Shelob's Lair" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
For video, I played the first ten minutes of the following on the Archos 7:
Cowboy Bebop the Movie
Serenity
Cars
Ironman
In setting a comfortable listening level, this time I found the Mustang and the Blackbird sounded the same with the Mustang volume at 11 o'clock and the Blackbird set at 1 o'clock. I did discover that I needed to adjust the Blackbird's volume in one case (as noted).
Same caveats as before... If you're willing to read, I'm willing to write.
Observations with the Denon AH-D2000 cans, amps at medium gain:
AC/DC - "Thunderstruck":
Mustang - Holy crap, Maynard!
I found the bass! Very prominent and punchy. Strong, but doesn't overwhelm the music. Wide soundstage.
Blackbird - I can feel the bass! Not as punchy, but what presence! Nice detail in guitar intro.
Blue Oyster Cult - "Godzilla":
Mustang - Wide soundstage. Overall good sound with solid, tight bass. Highs and mids are not so prominent.
Blackbird - Wider soundstage than Mustang. Not as detailed. Warm with equal emphasis on all frequencies.
Dire Straits "Sultans of Swing":
Mustang - Punchy bass tended to overwhelm the rest of the sound. Still has good mids and highs, but not prominent.
Blackbird - Very warm Solid bass with less emphasis on mids and highs. Had to lower volume to 11 o'clock to equal Mustang volume level.
Donna Summer "I Feel Love":
Mustang - Muddy bass. Not really detailed, with no outstanding qualities.
Blackbird - Heavy, muddy bass. Mids stand out and highs are too strong (fatiguing).
Eagles "Hotel California":
Mustang - Detail in intro is still present, now accompanied by strong, tight bass. Well rounded sound.
Blackbird - Bass is a little overwhelming and muddy. Mids and highs sound good.
Howard Shore/Emiliana Torrini "Gollum's Song":
Mustang - Strong bass presence but doesn't overwhelm mid or high end.
Blackbird - Well rounded sound with more emphasis on mids/highs. Bass is there but not as prominent as Mustang.
Howard Shore/Annie Lennox "Into the West":
Mustang - Analytical and detailed. Good mids/highs, with some, but not prominent, bass.
Blackbird - Warmth works in amp's favor. Strong bass and good mids. The highs are not emphasized, but there is no veil over them either.
Howard Shore "Shelob's Lair":
Mustang - Strong bass and mid-range presence. Sound tends to muddy up in the complex portions of the passage.
Blackbird - Stronger bass than Mustang, yet more detailed sound. Doesn't muddy up like Mustang.
The Moody Blues "The Day Begins":
Mustang - Well rounded sound. Detailed, but doesn't over emphasize anything.
Blackbird - Wide soundstage. Warm, with slight emphasis in mid/high end.
Cowboy Bebop the Movie (English dub):
Mustang - Wide soundstage. Detailed, but with good bass presence.
Blackbird - Soundstage not so wide. Bass is a touch muddier, but overall sound not that different than Mustang
Serenity:
Mustang - Nice detail with good, punchy bass. Good sound overall.
Blackbird - Not as detailed and low end is muddy.
Cars:
Mustang - Good bass presence. Well rounded sound.
Blackbird - Bass not prominent. Sound is OK with nothing overemphasized.
Ironman:
Mustang - Nice sound. Good detail in mid and upper range. Tight, punchy bass.
Blackbird - Good detail. Practically indistinguishable from Mustang.
Summary:
Apples to apples - This is a different can o' worms. The truth is both amps sound good. I believe the difference is which end of the mid range the amps emphasize. From my observations, the Mustang emphasizes the upper-mid range giving it a more detailed quality and the Blackbird emphasizes the lower-mid range, contributing to it's warmth. Since the Denons are closed-backed the bass is easier to drive and the Mustang can focus on the higher end. The Blackbird pushes the lower end, making the sound muddier.
I personally believe the Mustang has better synergy with the Denon cans. The Blackbird doesn't suit them so much.
So what cans does the Blackbird suit? Stay tuned...
Bonus Round
WHAT...There's more!?!
In the responses to part one of the comparison, someone mentioned that the sweet spot gain setting on the Blackbird is medium. I also wondered if the Mustang has the same characteristic. So I decided to conduct an abbreviated test and see if both amps could reasonably power my AKG K702 cans at medium gain. I then started to wonder about the results from part two. I noticed the Mustang tended to have better synergy with the Denon cans. But what about the Blackbird? With the closed-back Denon cans, the sound was muddier than the Mustang. I just happened to have a pair of Grado 325i cans with the GS1000 big donuts on them (much more comfortable to me). How would the Blackbird and Mustang sound with the Grados; open-backed and known for brightness? Another abbreviated test was in order!
This time, I only used four music tracks from the Cowon O2, alternating back and forth between the amps:
Dire Straits "Sultans of Swing" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Annie Lennox "Into the West" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
I would not be testing the video due to time constraints
In setting a comfortable listening level, this time I found the Mustang and the Blackbird sounded the same with the Mustang volume at 1 o'clock and the Blackbird set at 1 o'clock. However, I did have to make some volume adjustments (as noted).
Same caveats...you know the drill.
Observations with the AKG K702 cans, amps at medium gain:
Dire Straits "Sultans of Swing":
Mustang - Detailed, with prominent mids. No real bass presence.
Blackbird - Warmer with some bass present. Good detail, with wider soundstage.
Eagles "Hotel California":
Mustang - Detailed. Some bass present, but with fatiguing mids and highs.
Blackbird - Warm with slightly subdued mids and highs. Not fatiguing.
Howard Shore/Annie Lennox "Into the West":
Mustang - Good emphasis on mids and highs with only a slight bass presence. Had to adjust volume to 3 o'clock to reach adequate listening level.
Blackbird - Warmth contributes to well rounded sound. Had to adjust volume to 2 o'clock to reach adequate listening level, but sound would muddy if turned up louder.
The Moody Blues "The Day Begins":
Mustang - Nice, wide soundstage. Light on bass and not really detailed. However, turning volume up past 2 o'clock brought out more detail.
Blackbird - Kind of "eh" until I turned up the volume. Mids and highs improved, but not bass (and the volume was beyond my comfortable listening level).
Summary:
Apples to apples - I think this requires further study. As I mentioned in part one, I don't usually keep my EQ flat when I play music. I'm not sure the K702s are suited for mid gain, but I need more time to tell for certain.
...maybe other cans are, which leads me into...
Observations with the Grado 325i cans, amps at medium gain:
NOTE - Mustang and the Blackbird sounded the same with the Mustang volume at 11 o'clock and the Blackbird set at 12 o'clock.
Dire Straits "Sultans of Swing":
Mustang - Very detailed with good bass presence. Not punchy (that good open-backed sound)
Blackbird - Warm with emphasis on the lower-mid range.
Eagles "Hotel California":
Mustang - Not very detailed, but good bass presence. Slight emphasis on upper mids.
Blackbird - More detailed than Mustang. Well rounded sound.
Howard Shore/Annie Lennox "Into the West":
Mustang - Beautiful full range sound with no exaggeration.
Blackbird - Warm. Bass isn't muddy. Slight emphasis on lower-mid range. Still, overall nice sound.
The Moody Blues "The Day Begins":
Mustang - Nice, wide soundstage. Detailed. Bass is present but not overly strong.
Blackbird - Wide soundstage with a warm, full-bodied sound.
Summary:
Apples to apples - I think my Blackbird has found its niche. The Grados really sound good with this amp. The Mustang highlights the Grado's bright sound too much.
Final Thoughts:
Thanks for your patience in this. I want to thank everybody whose comment I received (and read), leading me to try out my first real comparison.
I think both of these amps are just fine, but they cater to different configurations. I think the big job is to find the Source, Cans, Cables (if you are into that sort of thing), and Music that each amp can can use to show its qualities.
I am sure the fun's not over. With further burn-in and experimentation, I think the quest for better sound is just beginning. Remember; these are my observations, your mileage may vary.
Lastly, I do apologize for not having IEMs. Someone else will have to fill that gap.
Good Luck to all.
Cheers,
-HK sends
After a battery of testing, I have come to the conclusion that this comparison needs to be in two parts. The first is using high gain settings with the AKG K702 headphone (with a Stephan Audio Arts replacement cable and 250+ hours burn-in). Part two will be with Denon AH-D2000 cans at medium gain settings.
OK, the contenders: In this corner, the RSA SR-71A Blackbird with over 200 hours of burn-in and using i-power 500 mAH Li-Ion batteries. In the other corner, the RSA P-51 Mustang with over 100 hours of burn-in and the internal battery.
This is to be an apples to apples comparison using the same music, sound source and cable. The sound sources are the Cowon O2 and Archos 7 IMT. I used a Cable Pro Panorama interconnect. And of course the K702 cans which, while not considered high impedance at 62 ohms, still requires a lot of power to drive. The cans are full range but don't really push bass frequencies without encouragement. However to be fair, I set the EQ on both players at +3dB above zero on all freq bands (while maintaining a flat level), so as not to unduly influence the sound.
I used the following tracks played on the Cowon O2, alternating back and forth between the amps:
AC/DC "Thunderstruck" (m4a)
Blue Oyster Cult "Godzilla" (m4a)
Dire Straits "Sultans of Swing" (m4a)
Donna Summer "I Feel Love" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Emiliana Torrini "Gollum's Song" (FLAC)
Howard Shore/Annie Lennox "Into the West" (FLAC)
Howard Shore "Shelob's Lair" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
For video, I played the first ten minutes of the following on the Archos 7:
Cowboy Bebop the Movie
Serenity
Cars
Ironman
In setting a comfortable listening level, I found the Mustang and the Blackbird sounded the same with the Mustang volume at 12 o'clock and the Blackbird set at 2 o'clock. I don't know if that means the Mustang puts out more power or if the Blackbird's volume is more conservative. Maybe, it is just the unique characteristics of the amps.
Lastly, I am by no means a professional reviewer. I will report the impressions the amps give me, but your experience or ability to characterize the sounds may vary. I simply want to offer my opinions and hope they brook some discussion. If you want me to clarify or restate my observation, let me know and I will try my best.
Observations with AKG K702 cans, amps at high gain:
AC/DC - "Thunderstruck":
Mustang - Mids and Highs are prominent. Bass is tight but rather subdued.
Blackbird - Wider soundstage but sounds a little distant. A warmer sound with a little more bass presence. Mids and highs are a bit subdued, but provide a more well rounded sound.
Blue Oyster Cult - "Godzilla":
Mustang - Gravitates toward high end with a slight bass presence. Sounds a bit "tinny"
Blackbird - Punched me in the ear with the first notes. Much warmer overall with less emphasis on high end.
Dire Straits "Sultans of Swing":
Mustang - Very analytical with a good level of bass and treble. Mids especially stand out. Bass isn't pounding, but a slightly better presence than previous tracks.
Blackbird - Warmer sound; not so analytical. Doesn't sound that different than the Mustang but it does make you feel a little more "into" the music.
Donna Summer "I Feel Love":
Mustang - Analytical with a hint of bass. Seemed like the low end was on the extreme edges of the soundstage (possibly due to my encoding).
Blackbird - Smaller soundstage, but the sound is more evenly spread out; possibly contributing to the warmth of the sound.
Eagles "Hotel California":
Mustang - The intro was outstanding; very detailed. I could easily make out every pluck of the strings. While the bass sometimes rises to the occasion, it is subdued for the most part.
Blackbird - Intro sounded muddier, more subdued. Overall the sound was well rounded with a good (but not overwhelming) bass presence.
Howard Shore/Emiliana Torrini "Gollum's Song":
Mustang - A beautiful, full-range sound with a good bass presence and very prominent mids. The violins accompanying Emiliana were very notable along with her haunting voice.
Blackbird - Rather muddy in all ranges. The high end sounded "veiled".
Howard Shore/Annie Lennox "Into the West":
Mustang - Very nice, well-rounded sound. Has more low-end presence with less emphasis on the high-end.
Blackbird - Warm but muddy low end with very little detail overall. The lower mid-range seemed overemphasized, almost overwhelming the rest of the music.
Howard Shore "Shelob's Lair":
Mustang - Surprisingly not as shrill or detailed in the high-end as I anticipated. While the bass was good and tight, the overall sound didn't really "wow" me.
Blackbird - Warmer and more subdued than the P-51 but with an overall better sound. The highs still seem "veiled". If I want to feel the "dread" of the passage, this amp conveys it better.
The Moody Blues "The Day Begins":
Mustang - Very detailed with a sweet spot in the upper mid range and the highs. The low notes are there but not prominent.
Blackbird - Warm with the sweet spot in the lower mid range. The high end isn't veiled either. the amp seems more suited for this piece of music. Excellent soundstage.
Cowboy Bebop the Movie (English dub):
Mustang - Very detailed; I could even hear the background music in the store. Spikes voice has good presence. The bass is there but not subwoofer quality (not punchy).
Blackbird - The soundstage wasn't very big. Nothing was really emphasized or stood out. Actually rather..."eh".
Serenity:
Mustang - Detailed with tight, but not punchy, bass.
Blackbird - Stronger bass with less detail in the highs. The warmth contributes to the movie, making it more enjoyable.
Cars:
Mustang - Where's the bass? Detailed mids and highs.
Blackbird - Warm, well rounded sound. Pleasant to listen to.
Ironman:
Mustang - Bass lacks punch.
Blackbird - More prominent bass with surprising detail in the high-end (especially gunfire).
Summary:
I have to agree with other reviewers that these amps have different sounds. You must realize that I usually adjust the EQ or DSP settings on my players to suit the sound. I rarely keep my EQ flat, emphasizing the treble and bass to push the sound to the headphones. Since the K702 isn't known for being bass-heavy, I tend to compensate a bit. But I really can't chose one amp above the other; so I'll keep both
Apples to apples - I think if you want to listen to the music itself, go with the Mustang. If you want the music to carry you away, the warmth of the Blackbird stands out. Kind of a letter-of-the-law vs. the spirit-of-the-law difference. For movies, I find the Mustang tends to edge out the Blackbird, with Irondude(man) being the exception.
These results are for one set of cans. As I have found, the so-called "missing bass" of the Mustang is there, you just have the right cans to appreciate it.
Next installment...
A comparison using the Denon AH-D2000 headphones.
Part Two
...and here...we...GO!
Same test as before but this time the amps are set to mid gain and I am using the Denon AH-D2000 with 50+ hours of burn-in.
I used the same tracks on the Cowon O2, alternating back and forth between the amps:
AC/DC "Thunderstruck" (m4a)
Blue Oyster Cult "Godzilla" (m4a)
Dire Straits "Sultans of Swing" (m4a)
Donna Summer "I Feel Love" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Emiliana Torrini "Gollum's Song" (FLAC)
Howard Shore/Annie Lennox "Into the West" (FLAC)
Howard Shore "Shelob's Lair" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
For video, I played the first ten minutes of the following on the Archos 7:
Cowboy Bebop the Movie
Serenity
Cars
Ironman
In setting a comfortable listening level, this time I found the Mustang and the Blackbird sounded the same with the Mustang volume at 11 o'clock and the Blackbird set at 1 o'clock. I did discover that I needed to adjust the Blackbird's volume in one case (as noted).
Same caveats as before... If you're willing to read, I'm willing to write.
Observations with the Denon AH-D2000 cans, amps at medium gain:
AC/DC - "Thunderstruck":
Mustang - Holy crap, Maynard!
Blackbird - I can feel the bass! Not as punchy, but what presence! Nice detail in guitar intro.
Blue Oyster Cult - "Godzilla":
Mustang - Wide soundstage. Overall good sound with solid, tight bass. Highs and mids are not so prominent.
Blackbird - Wider soundstage than Mustang. Not as detailed. Warm with equal emphasis on all frequencies.
Dire Straits "Sultans of Swing":
Mustang - Punchy bass tended to overwhelm the rest of the sound. Still has good mids and highs, but not prominent.
Blackbird - Very warm Solid bass with less emphasis on mids and highs. Had to lower volume to 11 o'clock to equal Mustang volume level.
Donna Summer "I Feel Love":
Mustang - Muddy bass. Not really detailed, with no outstanding qualities.
Blackbird - Heavy, muddy bass. Mids stand out and highs are too strong (fatiguing).
Eagles "Hotel California":
Mustang - Detail in intro is still present, now accompanied by strong, tight bass. Well rounded sound.
Blackbird - Bass is a little overwhelming and muddy. Mids and highs sound good.
Howard Shore/Emiliana Torrini "Gollum's Song":
Mustang - Strong bass presence but doesn't overwhelm mid or high end.
Blackbird - Well rounded sound with more emphasis on mids/highs. Bass is there but not as prominent as Mustang.
Howard Shore/Annie Lennox "Into the West":
Mustang - Analytical and detailed. Good mids/highs, with some, but not prominent, bass.
Blackbird - Warmth works in amp's favor. Strong bass and good mids. The highs are not emphasized, but there is no veil over them either.
Howard Shore "Shelob's Lair":
Mustang - Strong bass and mid-range presence. Sound tends to muddy up in the complex portions of the passage.
Blackbird - Stronger bass than Mustang, yet more detailed sound. Doesn't muddy up like Mustang.
The Moody Blues "The Day Begins":
Mustang - Well rounded sound. Detailed, but doesn't over emphasize anything.
Blackbird - Wide soundstage. Warm, with slight emphasis in mid/high end.
Cowboy Bebop the Movie (English dub):
Mustang - Wide soundstage. Detailed, but with good bass presence.
Blackbird - Soundstage not so wide. Bass is a touch muddier, but overall sound not that different than Mustang
Serenity:
Mustang - Nice detail with good, punchy bass. Good sound overall.
Blackbird - Not as detailed and low end is muddy.
Cars:
Mustang - Good bass presence. Well rounded sound.
Blackbird - Bass not prominent. Sound is OK with nothing overemphasized.
Ironman:
Mustang - Nice sound. Good detail in mid and upper range. Tight, punchy bass.
Blackbird - Good detail. Practically indistinguishable from Mustang.
Summary:
Apples to apples - This is a different can o' worms. The truth is both amps sound good. I believe the difference is which end of the mid range the amps emphasize. From my observations, the Mustang emphasizes the upper-mid range giving it a more detailed quality and the Blackbird emphasizes the lower-mid range, contributing to it's warmth. Since the Denons are closed-backed the bass is easier to drive and the Mustang can focus on the higher end. The Blackbird pushes the lower end, making the sound muddier.
I personally believe the Mustang has better synergy with the Denon cans. The Blackbird doesn't suit them so much.
So what cans does the Blackbird suit? Stay tuned...
Bonus Round
WHAT...There's more!?!
In the responses to part one of the comparison, someone mentioned that the sweet spot gain setting on the Blackbird is medium. I also wondered if the Mustang has the same characteristic. So I decided to conduct an abbreviated test and see if both amps could reasonably power my AKG K702 cans at medium gain. I then started to wonder about the results from part two. I noticed the Mustang tended to have better synergy with the Denon cans. But what about the Blackbird? With the closed-back Denon cans, the sound was muddier than the Mustang. I just happened to have a pair of Grado 325i cans with the GS1000 big donuts on them (much more comfortable to me). How would the Blackbird and Mustang sound with the Grados; open-backed and known for brightness? Another abbreviated test was in order!
This time, I only used four music tracks from the Cowon O2, alternating back and forth between the amps:
Dire Straits "Sultans of Swing" (m4a)
Eagles "Hotel California" (m4a)
Howard Shore/Annie Lennox "Into the West" (FLAC)
The Moody Blues "The Day Begins" (FLAC)
I would not be testing the video due to time constraints
In setting a comfortable listening level, this time I found the Mustang and the Blackbird sounded the same with the Mustang volume at 1 o'clock and the Blackbird set at 1 o'clock. However, I did have to make some volume adjustments (as noted).
Same caveats...you know the drill.
Observations with the AKG K702 cans, amps at medium gain:
Dire Straits "Sultans of Swing":
Mustang - Detailed, with prominent mids. No real bass presence.
Blackbird - Warmer with some bass present. Good detail, with wider soundstage.
Eagles "Hotel California":
Mustang - Detailed. Some bass present, but with fatiguing mids and highs.
Blackbird - Warm with slightly subdued mids and highs. Not fatiguing.
Howard Shore/Annie Lennox "Into the West":
Mustang - Good emphasis on mids and highs with only a slight bass presence. Had to adjust volume to 3 o'clock to reach adequate listening level.
Blackbird - Warmth contributes to well rounded sound. Had to adjust volume to 2 o'clock to reach adequate listening level, but sound would muddy if turned up louder.
The Moody Blues "The Day Begins":
Mustang - Nice, wide soundstage. Light on bass and not really detailed. However, turning volume up past 2 o'clock brought out more detail.
Blackbird - Kind of "eh" until I turned up the volume. Mids and highs improved, but not bass (and the volume was beyond my comfortable listening level).
Summary:
Apples to apples - I think this requires further study. As I mentioned in part one, I don't usually keep my EQ flat when I play music. I'm not sure the K702s are suited for mid gain, but I need more time to tell for certain.
...maybe other cans are, which leads me into...
Observations with the Grado 325i cans, amps at medium gain:
NOTE - Mustang and the Blackbird sounded the same with the Mustang volume at 11 o'clock and the Blackbird set at 12 o'clock.
Dire Straits "Sultans of Swing":
Mustang - Very detailed with good bass presence. Not punchy (that good open-backed sound)
Blackbird - Warm with emphasis on the lower-mid range.
Eagles "Hotel California":
Mustang - Not very detailed, but good bass presence. Slight emphasis on upper mids.
Blackbird - More detailed than Mustang. Well rounded sound.
Howard Shore/Annie Lennox "Into the West":
Mustang - Beautiful full range sound with no exaggeration.
Blackbird - Warm. Bass isn't muddy. Slight emphasis on lower-mid range. Still, overall nice sound.
The Moody Blues "The Day Begins":
Mustang - Nice, wide soundstage. Detailed. Bass is present but not overly strong.
Blackbird - Wide soundstage with a warm, full-bodied sound.
Summary:
Apples to apples - I think my Blackbird has found its niche. The Grados really sound good with this amp. The Mustang highlights the Grado's bright sound too much.
Final Thoughts:
Thanks for your patience in this. I want to thank everybody whose comment I received (and read), leading me to try out my first real comparison.
I think both of these amps are just fine, but they cater to different configurations. I think the big job is to find the Source, Cans, Cables (if you are into that sort of thing), and Music that each amp can can use to show its qualities.
I am sure the fun's not over. With further burn-in and experimentation, I think the quest for better sound is just beginning. Remember; these are my observations, your mileage may vary.
Lastly, I do apologize for not having IEMs. Someone else will have to fill that gap.
Good Luck to all.
Cheers,
-HK sends
