This technical write-up was developed to provide a detailed overview of the resto-modded Club Heaven Sound System, focusing on the make and model of both the original components that were recovered and the new parts that were installed. The information comes from a conversation between Audio Rescue Team founder and president Mike Fotias and DSC team member James Allen.
The Heaven sound system was recovered by Detroit Sound Conservancy in 2018. The recovered elements include:
- 4x Cerwin-Vega Earthquake 18” subwoofer drivers
- 4x subwoofer cabinets
- 2x Community mid-bass horns
- 2x JBL E120-8 mid-bass drivers
- 4x Altec-Lansing mid-high horns
- 4x replacement mid-high drivers
- Motorola Super Piezo Bullet tweeters
Water damage to the original subwoofer cabinets rendered them unsalvageable for the purposes of the restoration project. Two of the four cabinets were opened to measure the exact dimensions of the deep interior compartments. Those measurements, along with a partial set of original cabinet construction plans, were used to produce four exact replicas of the original subwoofer cabinets (constructed by Christopher Taylor at DCS Studios). The two remaining original cabinets belong to the DSC artifact collection of the Heaven sound system.
Two pairs of period-matching Electro-Voice DL18MT subwoofer drivers output the low-end inside of the subwoofer cabinets. The original Cerwin-Vega Earthquake 18” subwoofer drivers recovered with the system require significant repairs before they can be installed and activated as part of the reconstructed sound system. Those repairs are planned for a future phase of the sound system reconstruction.
Resting on top of the subwoofers, a pair of original system Community horns house the mid-bass drivers. The JBL E120-8 drivers are sold commercially as guitar amplifier speakers. This serves as a reminder of the custom nature of sound systems built during the Heaven era. The original JBL drivers found with the Heaven sound system were damaged beyond repair. A replacement pair was acquired through the vintage market and installed in the newly renovated system.
Continuing up the system stack, original Altec-Lansing horns house matching drivers that deliver the mid-high frequencies. When the sound system was initially recovered, previously installed replacement drivers were discovered in the mid-high horns, most likely installed during the course of operation of the system. As part of the restoration, matching Altec-Lansing 804A drivers were acquired and installed in the horns in order to restore the system back to its highest-performing original condition.
At the highest point in the speaker stack rests a series of tweeters that emit the highest frequency sounds in the system. These Motorola Super Piezo Bullet tweeters are the same models originally found with the Heaven system and have remained in production to the present day. New stock was acquired to complete the system reconstruction.
All of the speaker components in the Heaven sound system are passive, meaning they must be powered by external amplifiers. The amplifiers used at Heaven were produced by PAS, a Michigan-based electronics company. These amplifiers are no longer in production and are considered rare equipment in the vintage market. The reconstructed system uses a set of three amplifiers to power each speaker stack: QSC 1200 (mid-high & high), QSC 1400 (mid-bass), and BGW 750B (subwoofer). Original PAS amplifiers will replace the existing amplifiers upon their acquisition in the next phase of the system reconstruction.
An Ashly Model SC 77 crossover orchestrates which frequencies are delivered to each speaker. No crossover equipment was recovered with the Heaven sound system. However, the original sound system designer and installer was consulted throughout the restoration and advised that the Ashly crossover was the primarily deployed crossover at Heaven. The crossover is served by a stereo pair of DBX 161 compressors / limiters and a White Instruments Model 4500 equalizer.