Emulating the matching 70's spec'ed subs for my vintage speakers...


New Member
Feb 9, 2021
Portland, Oregon
Objective: Build two matching passive 8 ohm each with two 7 inch drivers (total 4) for my home hifi system.
Hifi system: Vintage Kenwood ss amp, rated 45 watts (but higher). Tube preamp. Art external crossover.
Music genre: Rock and Roll, both heavy and light
Characteristics of overall sound desired "Big soundstage"..clarity with warmth..Not after a vibrating booming sub (have that in my projector room), want to hear the drums in a realistic sound..
Main speakers: Each has two tweeters and two 6.5 drivers, 8 ohm all. They are doing ok with bass, but were originally recommended to have subs to pick up some of the load.
What's known about the optional subs (They appear to be about 24-30 inches tall. Both drivers were facing forward. Original boxes had cross overs and fed back to the main speakers, I'll use a centralized crossover.
What about this speaker? (See specs below)
If its a good fit for my needs, ..sealed or ported? Interior box space with internal foam? Speakers in separate departments? Optimal crossover settings for these speakers (will be four of them)?

Dayton Audio RS180-8 7" Reference woofer
Nominal Diameter 7"
Bolt Circle Diameter 6.63
Moving Mass Of Diaphragm (Mmd) 17.9
Power Handling (RMS) 60 Watts
Power Handling (MAX) 120 Watts
Impedance 8Ω
Frequency Response 39 to 3,600Hz
Sensitivity 87.1dB 2.83V/1m
Voice Coil Diameter 1.5"
Resonant Frequency (Fs) 35.7Hz
DC Resistance (Re) 6.4Ω
Voice Coil Inductance (Le) 0.73mH
Mechanical Q (Qms) 1.22
Electromagnetic Q (Qes) 0.42
Total Q (Qts) 0.31
Compliance Equivalent Volume (Vas) 0.86ft³
Mechanical Compliance of Suspension (Cms) 1.12mm/N
BL Product (BL) 7.82T·m
Maximum Linear Excursion (Xmax) 6mm
Surface Area of Cone (Sd) 124.7cm²
The Marantz PM7000N offers big, spacious and insightful sound, class-leading clarity and a solid streaming platform in a award winning package.