Infinity Studio Monitor 100's

Friend gave me these yesterday. Debating on refoaming or replacing drivers. The little I can find on them has them sounding meh lol. But the cabs look amazing and are in great shape. Tweeter supposed to be crap as well. Leaning towards replacing all drivers. The cabs are huge and have plenty of room to add a dedicated mid. Hell it has a 10" driver, but the cabs large enough for a 12".

Anyone have any experience with late 80’s infinity speakers on how they sound? I kinda like the dustcaps and look on the woofer. And lots of refoaming kits out there for them.

Anyways, keep on looking and listening! Never know what you may stumble on :slightly_smiling_face:

Those are pretty beat up, yeah. You could refoam them, but I do think swapping the drivers and the crossover would be pretty cool. I haven’t heard those specific models, but I have heard others in the range and they were good but nothing really impressive to me

Yeah thats kind of my thoughts. Leaning towards replacing drivers. the tweeters look kinda ugly to me, and are not that great from the little info i have on them. drivers might be bad or xover on one anyways, buddy said only one speaker works. id guess the xover at the attenuator went bad. So probably easier to just replace drivers anyways lol.

Also you might want to add more bracing and cabinet work to make them sound better because I’ve heard the cabinets are subpar from this era

My cats wont stay off them, they love em =D I think I will replace drivers, now to hunt for a combo.

Yeah i saw a teardown of a cerwin vega same time period, they all recommend bracing and stuffing. They are made out of particle board instead of mdf. plan on putting in 2 h brackets around the woofer, maybe a 3rd at the top. prolly just 1 strait brace at the top. i do not think i will be driving them to concert levels anytime soon, should be more then enough bracing off of the 2 H brackets, but if I am gunna brace may as well throw a 3rd at the top.

1 down.


Lookin good so far, any quality improvements or changes you made?

Used better drivers and xovers. Pearless tweeter grs woofer. Woofer was challenging finding a 10" that could be crossed at 2k. They just don’t really make them anymore lol. Also changed them to 4 ohms from 8 ohm. Putting the second together now. Will test when both done. Initial test on floor with drivers out they sound good. I need to build a work bench lol.


After much trouble shooting because I am an idiot and do not know as much as I think I do, I have them up and running and they sound amazing! DIY ish ftw lol. The peerless tweeter is omg good. Detail for days and days. Make out individual string notes for instance that were more fuzzy before and more of a blend all together and are now crystal clear. Those 20$ tweeters blow away the martin logan tweeters for detail. Q150’s sound shrill and unfocused comparatively.

Now all that being said, I think I need a warm dac, maybe tube amp to pair with them. They are to clinical(?) maybe for my tastes over all. I got a little mini hybrid tube amp with bass/treble control that helps to make them more enjoyable. Even the 10" woofer playing all the way up to 2k is crystal clear and thumping the whole time. I do not have measuring equipment, but to my ears these are very neutral. Like really really neutral lol. But I picked the drivers for their neutrality as a baseline to start my first build off of.

They are also 90db efficiency, so my mini amp @50wpc rms into 4 ohm’s drives them loud. Not insanely loud, but loud. Plenty loud for me, I go to about 2 o’clock on the dial. Tweek the high down a smudge and the bass up a smudge and I get a little warmer presentation that I prefer.

All and all took a little more effort then I initially anticipated, but well worth it. I am very happy with them in my first experiment in building.

edit: Meant to touch on comparison more. As much detail as there is, I do enjoy the other 2 sets of speakers just as much. I still think the martin logans are one of the best nearfields out there. And the q150’s have a very natural sound to them even if they are not as detailed as the new speakers. I think both sound more “natural” then my built speakers without further tweaking. But i put the studio back in studio monitor with my rebuild.

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And for the record: 10" " woofers fill rooms like no bookshelf can lol. Been over 20 years since i had a 10" woofer that wasn’t a sub. Forgot how much more encompassing a 10" woofer is. And I wasn’t sure I would like the 2k crossover point, but it is still just low enough that most treble comes from the tweeter still. But it does make the woofer directional like no tomorrow lol. The 1" soft dome and 10" woofer both have very large and good offaxis response lending to a very wide soundstage…as long as you are far enough back.

Just really enjoying listening to music w/o a sub and not really noticing it. All bookshelves I have owned get a bit boomy trying to go low with 5 1/4 woofers. some of the 6-7" woofer bookshelves might do better, but there’s no replacement for displacement as the saying goes.

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Now to find some cabs with 12" woofers someone is giving away and start my next adventure =)

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