Seas DXT 27tbcd (h1499)

Test Seas DXT 27TBCD / GB (H1499-06) 25mm dome with waveguide, 6 Ω

Datasheet ©
Measurements in DIN baffle in 70cm distance at 2,83V. Level scaled to 1m



Seas DXT 27TBCD / GB sound pressure & impedance (dispersion)


Very broadband and symmetrical superelevation from 800Hz to 10kHz, which can be easily equalized with the crossover. This is due to the waveguide and already a first indication of its effectiveness.

The efficiency reaches broadband 95dB but then drops down to 88dB in super high. In the case of linear tuning, therefore, no more than the named 88dB / 2,83V / m are achieved.

The impedance response is interference-free and shows a slightly asymmetrical "resonance hill" around 900Hz. More often seen in tweeters with coupling volume.

 Seas DXT 27TBCD / GB Sound pressure at angles (15 °, 30 °, 45 °, 60 °)


Extremely even directivity into the super high tone. In large parts near the so-called constant directivity Behavior.

Seas DXT 27TBCD / GB Decay behavior


Even and fast decay over all frequencies.

 Seas DXT 27TBCD / GB level linearity 85, 90, 95 and 100dB


Frequency response level corrected, based on the 85dB measurement

Even and low dynamic compression from 100dB / m <= 0,5dB (Please note the scaling => 20dB range)

Seas DXT 27TBCD / GB harmonic distortion


Extremely low harmonic distortion even at 100dB. K2 increases evenly with the level and remains below the 100% mark until 2dB starting at 1kHz.

K3 increasing below 2,5kHz, above that at the measurability limit.


Frequency response / directional behavior:5 5 out of stars
Range:4.5 5 out of stars
Power handling:4.5 5 out of stars
Consisty:4.5 5 out of stars
Haptics:4.5 5 out of stars
Price-performance:4.8 5 out of stars


Nowadays the straightening behavior of loudspeakers is getting more and more important. The Seas DXT stands out in this discipline from the competition. No other known tweeter of this size shows as uniform straightening as the Seas DXT.

However, a careful baffle design is required to maintain this behavior. In "normal widths" baffles (~ 20cm) for example. the Seas DXT tends to widen significantly at angles around 3kHz.

Work very well:

  • a practically nonexistent ...
  • or a very wide baffle.

See also here

Also in all other disciplines of the Seas DXT shows without blemish and blame.


One thought on “Test Seas DXT 27TBCD / GB (H1499-06) 25mm dome with waveguide, 6 Ω"

  1. Very interesting. I'm a bit surprised that the irregularities of the waveguide caused by the four screwholes and screwheads (apparently) have negligible negative influences, or is that logical considering the small dimensions of these holes and screwheads?
    Kind regards.

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