Infinity SM-105 Trash or Treasure

I have a set of Infinity SM-105's. They have been sitting around for some time in storage. I have read mixed reviews on these so I am taking it to the forums. I understand that they aren't "Studio Monitor" quality but they are here and paid for.

The Catch:

The boxes have seen better days...damn particle board. The woofer surrounds have rotted. Everything still functions but is in need of some restoration.

The Idea:

If it is worth it I would build some 3/4 MDF boxes for these and refoam the drivers and possibly give them a veneer for fun. I am guessing it will cost around $75 + time.

Should I set them on fire and recycle the drivers or bring them back to life???
 

Ron E

Member
2002-06-27 10:41 pm
USA, MN
I have a set of Infinity SM-105's. The woofer surrounds have rotted. If it is worth it I would build some 3/4 MDF boxes for these and refoam the drivers and possibly give them a veneer for fun.

I think it could be a fun project, but they won't be worth any more when you get done. The Polycell tweeters have a reputation for a certain shrillness, but others just call that detail. I've never seen a measurement of Infinity's of that era.

In the end, having fun with them is all that matters.
 

18Hurts

Member
2010-11-21 11:20 pm
Sounds like a fun project....worth it?

I owned a pair of Infinity SM-80's (2-way 8" woofer) and SM-152 with a 15" woofer, two 5 inch mids and the polycell tweeter. They are quite efficient as they competed against Cerwin Vega back in the day.

Worth messing with...for some retro fun and educational to do the work on a pair of speakers that won't cause the world to cry if you mess them up a bit.

Apex Jr. has those SM 10" woofers for $12.50 each which might be cheaper than the refoam kits. Scroll down to about the middle of the page. Here are the specs

Speaker Stuff

10" - 150 Watt at $12.50 ea

Parameter Value Unit/Notes
Effective piston area (Sd) 366.1 cm2
Free air resonance (Fs) 46.1 Hz
DC resistance (Re) 3.3 O
Mechanical Q factor (Qms) 3.572
Electrical Q factor (Qes) 0.827
Total Q factor (Qts) 0.671
Voice coil inductance (Le) 0.14 mH/milli-Henrys
Equivalent air volume (Vas) 76.2 Liters
Moving mass (Mms) 29.5 Grams/Mmd + air load mass
Suspension compliance (Cms) 405.10 µM/N/micro-Meters per Newton
Force factor (Bl) 5.807 Tm/Tesla-Meters
Sensitivity (SPLref) 91.4 dB/reference 8O/2.83Vrms