DIY : Ohm N2 Subwoofer Restoration
It's ALIVE!!!
We purchased a set of Ohm speakers (two satellites, one 8″ subwoofer) circa 1979. The units, while functional, had some components which had begun to deteriorate and an enclosure which had clearly seen better days.
While we were in midst of repairing the drivers with a kit from Simply Speakers, Ohm Acoustics sent a couple of refurbished drivers for the project, just in case the results of our efforts didn’t meet up to expectations. Those guys…
Ohm Acoustics
We were planning on just hooking up the old drivers and doing a sound test, but now that the Ohm drivers are here, we can do a side-by-side comparison with the new one. This will be fun!!!
Compare
Other than the color, logo, and a few small details, the old ones taken out of the enclosure and the “new” ones sent by Ohm Acoustics were pretty much identical. The Simple Speaker kit is spot on as a replacement. Note the Ohm sticker on the magnet of when they were made—June 12, 1980!
We were interested in how the ones repaired using the Simply Speakers foam surrounds sounded compared to the ones sent by Ohm Acoustics. To do that, we would have to re-install the drivers.
Re-Installation
For the comparison, we considered installing one set and then the other, but in the end we decided to see whether the “test” would work if we just installed one from each set…mostly out of laziness, LOL.
Reconnecting the drivers was easy as the terminals were clearly marked. Putting the drivers back into the enclosure was a bit trickier, as the heavy magnet in the rear of the unit made them awkward to handle.
However, after wrestling with them a bit, we realized that if we placed the enclosure so the opening was facing up (ie: parallel to the floor), we could easily align things without struggle…duh 🙂
Re-assembly complete. Yeah, the speaker cloth is a little bit beat up, but that is a project for another day!!!
Sound Check
We dusted off the old Onkyo receiver for the “sound test” of the Ohm N2 system. The receiver was purchased at the same time as the Ohm speaker system.
We have not used this receiver in decades…we are talking probably 30+ years. Amazingly, while some lights were out, the receiver basically STILL worked! You got to love the physical knobs for volume control and the all-aluminum enclosures for heat dissipation.
Newer receivers will use electronics to separately channel the high/midrange and low frequencies to the satellite speakers and subwoofers. However, that was not the case back in 1980.
The left and right signals from the amplifier is first connected to the subwoofer. There are electronics in the subwoofer to filter and redirect the high and midrange signals out to the satellites.
Once we had everything connected, we fired up the receiver, tuned it to the Classic Rock station in Boston (FM 100.7 WZLX) …and guess what they were playing?
After listening to a lot of different types of music and at various volume, we were not able to detect any difference between the repaired driver and the one sent by Ohm Acoustics!
We are satisfied with the results and declare this DIY complete! The only remaining question now is:
WHICH set of drivers should we send back to Ohm???
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