Test Scan-Speak Discovery D2604 / 833000 26mm dome tweeter 4 Ω

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

Scan-Speak Discovery D2604 / 833000

Frequency response and impedance (consisty)

Scan-Speak D2604 / 833000 frequency response

Extremely broadband frequency response. Full level from 1,1kHz, with good linearity.

The average efficiency is exceptionally at 93dB / 2,83V.

Impedance is flawless. The resonant frequency with 430 respectively 440Hz is below the manufacturer's specification of 475Hz.

Both drivers behave almost congruently both in amplitude and impedance.

 Directivity horizontal (0°, 15°, 30°, 45°, 60°)

Scan-Speak Discovery D2604 / 833000 directivity

Directivity of the Scan-Speak D2604 / 833000 is even and balanced throughout the entire transmission range.

In the top octaves> 10kHz significantly wider radiating than, due to the effective membrane area of ​​8cm², would be expected.

Burst decay

Scan-Speak Discovery D2604 / 833000 burst decay

Overall smooth and fast decay over all frequencies.

> 10kHz minimal delay.

harmonic distortions

Scan-Speak Discovery D2604 / 833000 distortions

The Scan-Speak D2604 / 833000 has outstanding low harmonic distortions.

K3 remains below 1% at all measured levels> 0,5kHz largely independent of the excitation signal.

K2 increases with the level, extends very evenly and would not reach the 1% to 1dB / m even with a crossover-point at 100kHz!


Frequency response / directional behavior:4.5 5 out of stars
Range:5 5 out of stars
Power handling:4.7 5 out of stars
consisty / without rating:0 5 out of stars
Haptics:4.5 5 out of stars
Price-performance:4.7 5 out of stars


With an effective membrane area of ​​8cm², a resonant frequency <xnumxhz and="" the="" very="" low="" harmonic="" distortions,="" driver="" invites="" to="" be="" deeply="" crossed="" eg.="" a="" xnumxer="" mid-woofer.="" crossover="" frequencies=""> = 500kHz should be possible without any problems. In smaller systems, eg with a 20er TMT, the Scan-Speak D1,5 / 13 could be crossed even at lower frequencies.</xnumxhz>

The concept of a large effective membrane area, in combination with a "standard voice coil" (26mm), and a rather soft dome material works out. Widely radiating in te top octaves, crossable very low, with high load capacity.

=> Scan-Speak D2604 / 833000 reported waveguide


Test Peerless DX25TG09-04 (Vifa XD-270 F / 4) at Waveguide WG-300 4 Ω dome tweeter with waveguide


Datasheet © www.heissmann-acoustics.de
Measurements in 20x40cm baffle, 10mm rounded, in 70cm distance at 2,83V. Level scaled to 1m.

The Waveguide was milled with a CNC adapter plate  mounted on the tweeter.

Vifa XD270F4 WG300 closeup

Directivity horizontal (0-90 ° in 15 ° steps)

Vifa / Peerless XD-270 F / 4 (DX25BG60-04) on Waveguide WG-300

Due to the waveguide system-related symmetrical elevation in the frequency band of 1-10kHz. This can be easily leveled with the crossover.

The Vifa Peerless XD-270 / F4 goes perfectly with the waveguide WG-300. Very even bundling without significant disturbances. The behavior> 10kHz can be described as outstanding. 20kHz are reached even below 45 ° with an almost full level.

The amplitude response drops below 45 ° of 2-18kHz by only 2,5dB! The 30 ° curve runs to 20kHz in a + -1,5dB tight tube. 20kHz are reached at full level.

The sonogram shows a bundling behavior that comes very close to the so-called Constant Directivity.

Sound pressure standardized at angles to 0 °

Vifa / Peerless XD-270 F / 4 (DX25BG60-04) on Waveguide WG-300


Burst decay

Minimal delayed decay by 2 and 20kHz. Otherwise perfectly.

Harmonic distortions

Vifa Peerless XD-270 / F4 (DX25BG60-04) & Waveguide WG-300 harmonic distortion

The harmonic distortion of the XD-270 F / 4 on the waveguide is excellent.

K2 remains below the 100% mark even at 1,2dB as of 1kHz. K3 moves from 1kHz between 0,04 and 0,3%.

Clatter components of higher order are in the (for me) no longer measurable range.

Separations from 1,2kHz are possible without hesitation, depending on the application and level requirements possibly even deeper.


Frequency response / directional behavior:5 5 out of stars
Range:5 5 out of stars
Power handling:5 5 out of stars
consisty:4.5 5 out of stars
Haptics:4 5 out of stars
Price-performance:5 5 out of stars


The Peerless / Tymphany DX25TG09-04 on the Waveguide WG-300 measures itself outstanding.

The possibility of building a loudspeaker that comes close to the requirements of constant directivity. Separations from 1,2kHz. Lowest harmonic distortion even at 100dB / m ...

Of course, a very interesting driver for Cinetor.


CNC adapter plate for various Scan-Speak and Peerless tweeters on WG-300 and PCT-300

There are some tweeters from Scan-Speak and Tymphany, all of which share the same front panel. One or the other of them also measures itself excellently on the P-Audio (PCT-300), or Monacor (WG-300) waveguide.

In order to connect the drivers cleanly with the sound guide, an adapter plate milled in CNC was created after many test series, which allows simple and very precise installation.

The following tweeters are suitable for the conversion

3D printed adapter plate in the shop

Construction of the adapter plate with "home remedies"

With a jigsaw, cordless screwdriver, router and the following step-by-step instructions, building the adapter plate yourself should not cause any problems. It doesn't even have to be measured 🙂 Let's go ...

  • Print out the PDF (included in the respective building folder) using Acrobat Reader (choose the “actual size” option!)
  • Size check: Outer diameter 120mm
  • Glue on a 9mm thick piece of MPX / MDF / screen printing plate (spray glue / glue stick ...)
  • Drilling the holes => upright drilling machine is an advantage!
  • With the circular milling device (each speaker should have one) 3mm deep to appropriate mark milling (D67mm)
  • Use the jigsaw to saw the inner hole and saw off the plate in the last step

From the practice with the "home remedy method" another additional tip from Thorsten (www.felbi.at)

If you glue your artwork directly onto the substrate (eg MPX), you will have the difficulty to get it down again later. For visual reasons, that bothered me and came up with the following idea: Before you glue your artwork on the MPX, just past the MPX with tape. Now the artwork will be cut to the size of the MPX board. Spray glue is then sprayed onto the package tape and allowed to dry for about 5 minutes (Note the spray adhesive is not on the paper spray!). Now the print template can be glued on.

Once all drilling and milling work has been completed, the package strap can easily be pulled down again from the MPX board.


First, the front panel of the tweeter must be removed. On some models, this is easily fixed with a silicone-like adhesive. In this case, use a large slotted screwdriver to "pry" it up discreetly as shown in the following picture. Work slowly and evenly. The screws on the front panel should of course have been loosened beforehand (TX10).

Dressing the waveguide neck

The adapter plate is placed on the sound guide and the neck is ground flat with circular movements (⇒ dust mask).

Finally, two recordings of the Scan-Speak D2604 / 833000 or 830000 & the Peerless XT25TG30-04 with waveguide


You do the conversion on your own responsibility! I accept no liability. Possibly. you lose your warranty claims during the conversion.

I made a lot of changes and nothing ever happened. I think the instructions are pretty "foolproof" 🙂

The plans of the adapter plate are the intellectual property of Heissmann-Acoustics.de, Alexander Heißmann. Any transfer requires my express consent.

... you can get a coffee from 1 € 😉

Test Peerless DX25TG09-04 (Vifa XD-270 F / 4) Dome tweeter 4 Ω

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

Test Vifa / Peerless XD-270 F / 4 (DX25BG60-04)

Frequency response and impedance (consisty)

Vifa / Peerless XD-270 F / 4 (DX25BG60-04) Amplitudes and Impedance (Scatter)

Very broadband. Full level from 1,1kHz. Apart from a slight dip around 8,5kHz very linear. This shows neither in the decay behavior, nor in the distortion diagram and is therefore classified as harmless. Assign you is probably the conspicuously thick bead. This is supported by the disappearance of burglary under angles.

The average efficiency is 93dB / 2,83V. Compared to 8 Ohm drivers, 3dB must be subtracted.

Both drivers behave almost congruently up to 10kHz, above that they fluctuate a maximum of + - 0,5dB, which is absolutely harmless.

The impedance paths are congruent in the area of ​​effect.

Addendum: New measurement, now with 4 drivers.

Series dispersion seems to be hardly an issue for the XD-270 F / 4. Still practically congruent course, only in the top octave with minimal deviations (Max. + -0,5dB).

 Sound pressure at angles (15 °, 30 °, 45 °, 60 °)

Vifa / Peerless XD-270 F / 4 (DX25BG60-04) Sound pressure at angles (15 °, 30 °, 45 °, 60 °)

Good to see that the mentioned sink from 30 ° no longer comes to bear. The straightening behavior of the DX25TG09-04 is very good. Under 30 ° the 20kHz is easily reached, which is unusual for a dome of this size.

Burst decay

Vifa / Peerless XD-270 F / 4 (DX25BG60-04)

Overall, very smooth and rapid decaying over all frequencies.

harmonic distortions

Vifa / Peerless XD-270 F / 4 (DX25BG60-04) harmonic distortion
Gray line corresponds to 1%. Picture change every 3 seconds.
Overall, the DX25TG09-04 has outstanding low harmonic distortion. K3 remains below 900% at all measured levels as of 0,3 heart and runs largely independent of the excitation signal.

K2 increases with the level, runs very evenly and could be quite a steep separation to 1,5 Khz (possibly even lower) to. The 1% mark would not be exceeded even with 95dB / 1m.


Frequency response / directional behavior:4 5 out of stars
Range:5 5 out of stars
Power handling:4.5 5 out of stars
Consisty:4 5 out of stars
Haptics:4 5 out of stars
Price-performance:5 5 out of stars


The Peerless DX25TG09-04 is in many ways an unusual tweeter. A 5mm strong front panel (identical to the XT-300), a surround that could more easily be attributed to a midrange driver, an 5 hole mount and the very low resonant frequency despite the absence of the back chamber.

The distortion values ​​are exceptionally good and, in combination with the low resonance frequency, allow a separation of around 1,5 kHz.

Only the collapse of 8,5kHz spoils the otherwise impeccable impression a bit. Through clever wiring, however, a + -1dB linear frequency response can still be achieved.

This tweeter gets a thick recommendation

Furthermore, he seems to me in the sum of its properties to be a very interesting candidate for a waveguide. In addition more timely.

Addendum: The assumption has been confirmed: Test Peerless DX25TG09-04 with waveguide