Presented below is a new 2-way mini monitor featuring Seas ER18RNX mid-woofer and Scanspeak Discovery D2608/9130 HDS tweeter (formerly Peerless HDS 810921).
ER18 RNX is a paper reed cone 7” mid-woofer from Seas Prestige line. It has a relatively smooth response and mild break-up at 4.5 kHz. It also has a copper sleeve on T-shaped pole piece which translates into lower distortion in the lower midrange. This driver has a good bass extension upto 45 Hz (-3db) in a smallish 14 litre vented enclosure. But this mid-woofer has to be crossed as low as 1600 Hz as distortion of this driver rises above that 1000 Hz. So Scanspeak Discovery HDS tweeter has been selected for the design.
I have used 15 AWG steel laminate for the main woofer inductor and 18 AWG air core elsewhere. All capacitors are polymer based and resistors are metal film type. You can swap R3 and R4 if you find the speakers little bright.
The enclosure is Madisound MD14 back ported with no tweeter offset. The port is 2” flared port 7” long.
You can also build your own enclosure with 1” MDF. External box dimension should be 8.5” (w) x 12” (d) x 16” (h) and the port is to be placed right behind the tweeter.
This is a decent performing mini monitor with good bass extension which generally not found on any loudspeaker of this size. Midrange is nearly as good as my Rediscovery tower. Drivers are relatively cheap. This is a budget high end audio.
ER18 RNX is a paper reed cone 7” mid-woofer from Seas Prestige line. It has a relatively smooth response and mild break-up at 4.5 kHz. It also has a copper sleeve on T-shaped pole piece which translates into lower distortion in the lower midrange. This driver has a good bass extension upto 45 Hz (-3db) in a smallish 14 litre vented enclosure. But this mid-woofer has to be crossed as low as 1600 Hz as distortion of this driver rises above that 1000 Hz. So Scanspeak Discovery HDS tweeter has been selected for the design.
I have used 15 AWG steel laminate for the main woofer inductor and 18 AWG air core elsewhere. All capacitors are polymer based and resistors are metal film type. You can swap R3 and R4 if you find the speakers little bright.
The enclosure is Madisound MD14 back ported with no tweeter offset. The port is 2” flared port 7” long.
You can also build your own enclosure with 1” MDF. External box dimension should be 8.5” (w) x 12” (d) x 16” (h) and the port is to be placed right behind the tweeter.
This is a decent performing mini monitor with good bass extension which generally not found on any loudspeaker of this size. Midrange is nearly as good as my Rediscovery tower. Drivers are relatively cheap. This is a budget high end audio.
