TSW 510 WOOFER IMPEDANCE QUESTION

[lARrybody]

I was driving to the grocery store two Saturdays ago and I pass a garage sale sign. In the spirit of social distancing I slowly pass by looking up the driveway I see two floorstanding speakers that appear to be Advent Prodigy's. Parking and putting on my mask I walk up  to take a closer look.  They weren't Advents at all, but had AR emblems. They were TSW 510 in relative nice shape. The homeowner said they were inherited from a uncle and there were two smaller bookshelf speakers (TSW 100) to go with them. This was the first pair of TSW speakers I have encountered in person. I knew  they were from later on (1989), but they did say Teledyne Acoustic Research on them. Upon negotiation and after a major reduction in the asking price I loaded them into my SUV. Here they are back home.

 

One of the small 100's is missing the Acoustic blanket around the tweeter. One of the woofers on the 510's is different, not a poly cone. I hooked them up to a sacrificial Lepai T-amp  and Sony Walkman and they sounded pretty good.

The paper coned woofer turned out to be a AB tech replacement. It had a DCR of 7.7 ohms. There was no gasket sealing the woofer in the cabinet.

I removed the poly cone woofer and it had a DCR of 3.7 making it a 4 ohm driver. The TSW 510 is rated at 4 ohms.

After re-installing the woofers with gasket tape and doing some listening I could not detect any differences in sound or volume from either woofer. How big  of difference should a 4 ohm and 8 ohm speaker have? What will this mean to a amplifier?  Should I look for the correct woofer?

Thanks  Larry

[RoyC]

Hey Larry,

Technically there would be a shift in the original crossover point as well as less sensitivity in the speaker with the replacement woofer, but if you can't hear a difference I wouldn't worry about it. The amp should have no functional issues. If audible difference are slight, room placement and balance controls can be helpful.

Roy