Vintage SEAS 25 K speaker cabinet

FA22RCZ H5197-08 full range driver upgrade

This speaker project were meant as a simple method to get some seventies styling with modern speaker drivers.

SEAS Type 25 K baffle

SEAS Type 25 K's low cost industrial look, with its rounded corners are somewhat apealing to me. Way back these speakers where often found in public buildings and these two not really originated as a pair came out of a school many many years ago.

The K in the model name most likely stand for kabinett, the Norwegian word for cabinet. Seas Type 25 where a series of 10 inch speaker drivers where these cabinetts where equipped with the TV D version (40-18000Hz / 7 Watt).

Type 25 list

Type 25 list

Compared to the vintage speaker drivers I don't expect the new drivers to play much more bass in the open back cabinet, but I hope they will handle more power with some authority and less fart. Size of magnet are significant at least — together with much longer linear coil travel.

New driver Freq

Wanting to keep the front baffle original without ruining the fabric mounting the new SEAS FA22RCZ (H1597-08) speaker drivers would take a little more work than first anticipated.

I was hoping the outher diamter of the new driver would slip inside the old 10" cutout so I could make a wooden ring it could seat on — mounted flush with the baffle from the back. But the new driver are approx 4mm to big and would not fit into the 10" cutout.

Due to the depth of the driver it need to be seated flush to the back of the baffle. Which meant a flange had to be routed in a new baffle — with speaker driver mounted to the new baffle from front, and then the new baffle is mounted on back of the cabinett baffle. In prinsipple new speaker driver are now mountet at the same level as the original driver where.

Driver mounted

SEAS Type 25 K front

Type 25 D

Type 25 TV D magnet

FA22FCZ magnet

The FA22RCZ is an 8” full range driver offering astonishing efficiency and sound clarity.

A blue-gray paper cone with papyrus fibres, and a high frequency cone directly coupled to the voice coil set the air in motion.

The surround is made from a flexible and stable foam rubber material. The large, open weave fabric spider refl ects very little acoustic energy to the cone, and offers excellent stiffness linearity.

A heat resistant, non conductive glass fiber coil former allows a high mechanical Q of the moving system. A large ferrite ring magnet offers a high magnetic gap flux in a cost efficient way.

The pole piece is prolonged forwards and equipped with a deep drawn copper cap to ensure excellent linearityin the force factor and coil inductance.

A stiff and stable injection moulded zinc chassis keeps the critical components in perfect alignment. Large windows in the chassis both above and below the spider reduce sound reflexion, airflow noise and cavity resonance to a minimum.

SEAS datasheet

type25k/seas_fa22rcz_cabs.jpg
To view high resolution images, right click on image and select View image or Save image

Select file from list below

FA22RCZ_app_note.pdf
366.4K Compressed file
FA22RCZ_datasheet.pdf
104.7K Compressed file
seas_type_25d_chart.png
388.9K
seas_cabs.jpg
2.5M
seas_cabs2.jpg
1.6M
seas_fa22rcz_4.jpg
952.6K
seas_fa22rcz_back.jpg
2.4M
seas_fa22rcz_baffle.jpg
1.2M
seas_fa22rcz_baffle2.jpg
1.3M
seas_fa22rcz_cabs.jpg
788.4K
seas_fa22rcz_driverback.jpg
822.7K
seas_fa22rcz_frequency.jpg
300.0K
seas_fa22rcz_front.jpg
2.1M
seas_fa22rcz_glue.jpg
596.7K
seas_fa22rcz_openback.jpg
2.4M
seas_fa22rcz_parts.jpg
969.0K
seas_fa22rcz_sealing.jpg
2.5M
seas_fa22rcz_sealing2.jpg
2.6M
seas_type_25d_01.jpg
398.1K
seas_type_25d_02.jpg
372.6K
seas_type_25d_03.jpg
422.0K
seas_type_25d_04.jpg
249.0K
seas_type_25d_05.jpg
222.3K
seas_type_25d_06.jpg
252.6K
seas_type_25d_07.jpg
199.3K
seas_type_25d_08.jpg
287.0K
seas_type_25d_09.jpg
1.4M
seas_type_25d_10.jpg
1.3M

Comments

Your comment are welcome

Name:


Email: optional, will be hidden


Comment: