Short answer: the Definitive Technology Demand D11 for better sound quality, the Klipsch RP-600M II for the lower price. The Definitive Technology Demand D11 ranks #44 of 100 bookshelf speakers at $999. The Klipsch RP-600M II ranks #53 at $489.99, $509.01 cheaper.
The case for the Definitive Technology Demand D11: CEA2034 spinorama shows a mostly flat, well-controlled response - close to class-leading if not for one narrow resonance. The tradeoff: A narrow but real ~600Hz jaggy shows up consistently in on-axis and off-axis measurements.
On the Klipsch RP-600M II side: Redesigned waveguide extends flush to the baffle edge, reducing diffraction compared to the original RP-600M. Set against that: On-axis, the treble runs notably hot - even hotter than the original RP-600M in some respects - and needs about 20° of toe-out or the grille installed to sound balanced.
Buy the Definitive Technology Demand D11 if sound quality matters more than the price. Buy the Klipsch RP-600M II if the price matters more than sound quality.
Specifications Side By Side
| Definitive Technology Demand D11 | Klipsch RP-600M II | |
|---|---|---|
| Price | $999 Discontinued | $489.99 |
| Ranked | #44 of 100 in Large Size Bookshelf Speakers | #53 of 100 in Large Size Bookshelf Speakers |
| Bass Extension (-3dB) | 80Hz (measured, Audio Science Review) | 70Hz (measured, Erin’s Audio Corner) |
| Bass Extension (-10dB) | 62Hz (measured, Audio Science Review) | 41Hz (measured, Erin’s Audio Corner) |
| Drivers | 6.5" BDSS polypropylene woofer, 1" aluminum dome tweeter (offset), 6x10" oval passive radiator | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn |
| Discontinued | Yes | - |
| Dimensions | 13H x 7.25W x 12.5D in | 15.7"H x 8"W x 12.5"D (398.8 x 203.2 x 317.5 mm) |
| Weight | 17 lbs each | 13 lbs / 5.9 kg each |
| Frequency Response | 48Hz - 24kHz (61Hz - 22kHz -3dB) (Manufacturer specified) | - |
| Sensitivity | 87dB (2.83V/1m, measured, Audio Science Review) | 86dB (measured, Erin’s Audio Corner) |
| Impedance | 8 ohms nominal | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin’s Audio Corner) |
| Power Handling | 20-200W recommended | - |
| Woofer Cabinet | passive radiator | ported |
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The Two Speakers In Full
Definitive Technology Demand D11: $999 Discontinued Amazon
Pros: CEA2034 spinorama shows a mostly flat, well-controlled response - close to class-leading if not for one narrow resonance. Distortion is well controlled and the deep cabinet lets it play loud without bottoming out except on the deepest bass content. Cabinet construction and finish are a clear step above budget speakers.
Cons: A narrow but real ~600Hz jaggy shows up consistently in on-axis and off-axis measurements. Horizontal directivity is uneven because of the offset tweeter position, giving the left and right channels slightly different off-axis energy. There’s a low-frequency rattle/noise at very deep bass levels the reviewer called “horrendous.” Discontinued; the Demand series has moved on to newer models. Discontinued.
Full Definitive Technology Demand D11 review and specifications →
| Bass Extension (-10dB) | 62Hz (measured, Audio Science Review) |
|---|---|
| Bass Extension (-3dB) | 80Hz (measured, Audio Science Review) |
| Dimensions | 13H x 7.25W x 12.5D in |
| Discontinued | Yes |
| Drivers | 6.5" BDSS polypropylene woofer, 1" aluminum dome tweeter (offset), 6x10" oval passive radiator |
| Frequency Response | 48Hz - 24kHz (61Hz - 22kHz -3dB) (Manufacturer specified) |
| Impedance | 8 ohms nominal |
| Power Handling | 20-200W recommended |
| Sensitivity | 87dB (2.83V/1m, measured, Audio Science Review) |
| Weight | 17 lbs each |
| Woofer Cabinet | passive radiator |
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- Reviews, Comparisons and Sound Samples
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- Definitive Technology Demand D11 vs Revel Concerta2 M16
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Klipsch RP-600M II: $489.99 Amazon
Pros: Redesigned waveguide extends flush to the baffle edge, reducing diffraction compared to the original RP-600M. Roughly 10-20° wider horizontal radiation than the original, giving more soundstage envelopment while retaining precise imaging. A major step up in overall tonal neutrality compared to the original RP-600M, largely eliminating that model’s midrange resonance issues. Unusually, sounds better with the grille on - the grille smooths out the elevated treble rather than degrading the sound, a rare trait among speakers the reviewer has tested. More refined back-panel hardware, including anodized binding posts and jumper cables for optional bi-amping. Responds well to EQ correction (verified using measurement software and a miniDSP), letting the on-axis response be made genuinely linear.
Cons: On-axis, the treble runs notably hot - even hotter than the original RP-600M in some respects - and needs about 20° of toe-out or the grille installed to sound balanced. Horizontal dispersion is very slightly less linear across angles than the original RP-600M, a minor trade-off for the wider overall radiation pattern. Klipsch’s marketed sensitivity (about 94.5dB) is, like the original, a half-space rating roughly 9dB above the anechoic reality (closer to 85-86dB). In-room bass rolls off around 60Hz in practice, and a 120Hz boost paired with a midrange scoop gives kick drums their “tambour” without real low-end weight - a subwoofer is still recommended. Vertical listening tolerance is limited to about ±10° from the tweeter axis. Toeing the speaker out for better on-axis tonality (rather than using the grille) introduces slightly more diffuse imaging from added sidewall reflections.
Full Klipsch RP-600M II review and specifications →
| Bass Extension (-10dB) | 41Hz (measured, Erin's Audio Corner) |
|---|---|
| Bass Extension (-3dB) | 70Hz (measured, Erin's Audio Corner) |
| Dimensions | 15.7"H x 8"W x 12.5"D (398.8 x 203.2 x 317.5 mm) |
| Drivers | 6.5" Cerametallic cone woofer, 1" titanium LTS vented tweeter with Tractrix horn |
| Impedance | 8 ohms nominal (3.5 ohms minimum above 80Hz, measured by Erin's Audio Corner) |
| Sensitivity | 86dB (measured, Erin's Audio Corner) |
| Weight | 13 lbs / 5.9 kg each |
| Woofer Cabinet | ported |
As an eBay Partner, we may be compensated if you make a purchase.
- Links
- Reviews, Comparisons and Sound Samples
- Erin’s Audio Corner: The Truth about Klipsch’s “NEW” Sound. RP-600M Update.
- Erin’s Audio Corner Website Klipsch RP-600M II
- GR-Research: We Bought The “NEW” RP-600M II Is KLIPSCH Listening?!
- Erin’s Audio Corner: 5 AWESOME SPEAKERS Under $1000 You Won’t Regret
- Reddit Search for Klipsch RP-600M II Review
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