Infinity Crescendo CS-3007 restoration

I finally got my Infinity Crescendo CS-3007s back together today, and thought I'd share some pictures.

The first one concerns the midrange, and is an excellent reminder of why I don't use generic foams. Actually, I bought a surround kit from an eBay seller who said the kit was specifically for the CS-3007s. When I trial fitted the midrange surrounds though, they looked a lot smaller than what was originally fitted. I contacted both Rick Cobb and Tom at myaudioaddiction, and gave them the ABCD measurements. Rick didn't have anything that matched, but Tom did. The picture below shows the eBay foams on the right, and the foams I got from Tom on the left (trial fitted). Luckily, I was able to send the "kit" back to the eBay seller for a full refund.



If you prefer to shim your woofers, the dust caps on these can easily be removed. Just don't bite or cut your fingernails for a week, and they are an excellent tool for lifting the dustcap up. Once started, a yellow spreader the kind used for auto body filler can be used to remove it completely.


Here they are shimmed and gluing. A couple of points to note here. The plastic trim rings were removed by carefully going around the inner edge with a flat blade screwdriver. Once all the old foam has been scraped off, I used Goof-Off to remove the last residue from the cones and dust caps. I used the correct black glue for the surround to cone join, and white glue for the surround to basket join. I already had two 8" surrounds that I got from Rick for some other Infinity's that I didn't end up refoaming, so I used these and ordered two more. The woofer surrounds laid flat on the edge and didn't need to be pegged, but I used pegs on the mids as the edges kept wanting to lift up.




Look at the cabinet bracing in these babies. Front to back and side to side above both woofer openings.



And here they are with the drivers installed.





I haven't done anything with the crossovers yet. They have a film cap already for the tweeter, I might get a film for the inline cap to the midranges, and maybe some new electrolytics for the midrange and woofer shunt caps.

Thanks to Tom over at myaudioaddiction, and to Rick Cobb for the surrounds.

Lee.

Nice job. Those look as good as new! Great looking cabinets.
Jim

good work.

it can be hard to find glue that bonds well to IMG cones. you mentioned "correct" black and white glue. what exactly did you use, and where did you get it?


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slimpikkins said:

Nice job. Those look as good as new! Great looking cabinets.
Jim

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Thank you! I sanded the baffles down and gave them a coat of Tung oil.

loquatious said:

good work.

it can be hard to find glue that bonds well to IMG cones. you mentioned "correct" black and white glue. what exactly did you use, and where did you get it?

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Thanks again. I think the black glue came from Orange County Speaker, the white glue is Aileen's.

Lee.

nice work...

Gee, I hope the kit I just ordered from an eBay seller will fit my Kappa 5.1 IIs which appear to have drivers similar to yours.

I've been using these for about a week now. They have a really impressive bass response, smooth mids and detailed highs. Sometimes, it might seem like the highs aren't as loud, but I think it's more because the tweeters aren't adding any distortion or shrill edginess to the sound.

I think I read somewhere these speakers are supposed to need a lot of power. Not true. I can drive them to very loud levels using just a 20w NAD 3020 amp.

Lee.

What is this correct black glue you mention in post one?

stereofanboy said:

What is this correct black glue you mention in post one?

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I think I got it from Orange County Speaker. Personally, I think it's no different to Aileen's except for it's color, it certainly doesn't smell any different. But it's "supposed" to be the correct type for IMG and other polypropylene cones, so I used it.

Lee.

leesonic said:

I've been using these for about a week now. They have a really impressive bass response, smooth mids and detailed highs. Sometimes, it might seem like the highs aren't as loud, but I think it's more because the tweeters aren't adding any distortion or shrill edginess to the sound.

I think I read somewhere these speakers are supposed to need a lot of power. Not true. I can drive them to very loud levels using just a 20w NAD 3020 amp.

Lee.

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at 20 watts, your crescendos are not giving anywhere near what they are capable of, which is why the highs might seem recessed. the emit-r is amazing when fed the watts it wants, and the same goes for the IMG drivers. those speakers won't really wake up unless you give them 100 watts (or more). 20 watts is less than the absolute minimum recommended power and can actually lead to damaging the emits.



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loquatious said:

at 20 watts, your crescendos are not giving anywhere near what they are capable of, which is why the highs might seem recessed. the emit-r is amazing when fed the watts it wants, and the same goes for the IMG drivers. those speakers won't really wake up unless you give them 100 watts (or more). 20 watts is less than the absolute minimum recommended power and can actually lead to damaging the emits.

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If I'm listening to them with the 1w LED flashing continuously on the power meter, I should be hearing around 90dB. I'm going on the sensitivity rating of 90dB per 2.83v, and that at 8 ohms, 2.83v translates into 1w (it would be 2w if they were 4 ohms). It doesn't matter if it's a NAD, Naim, McIntosh or Marantz. 1w is 1w, and I doubt whether the designers at Infinity set out to make some speakers that would only sound good at high volume levels.

All this stuff about speakers "not waking up" or needing megawatts of power in order to sound their best is a load of crap, unless the speakers in question are really inefficient, which these aren't. Granted, I'll agree that my little 20w amp will run out of steam if asked to produce stadium level volumes, but then I don't feel the need to listen to music at deafening levels in order to enjoy it. You hear stories of people running their system and popping circuit breakers before it's even turned all the way up. Each to their own I suppose.

Lee.

p.s. I found the reason for the highs not being so loud. When using a turntable, I had the phono cartridge loading set wrong.

leesonic said:

If I'm listening to them with the 1w LED flashing continuously on the power meter, I should be hearing around 90dB. I'm going on the sensitivity rating of 90dB per 2.83v, and that at 8 ohms, 2.83v translates into 1w (it would be 2w if they were 4 ohms). It doesn't matter if it's a NAD, Naim, McIntosh or Marantz. 1w is 1w, and I doubt whether the designers at Infinity set out to make some speakers that would only sound good at high volume levels.

All this stuff about speakers "not waking up" or needing megawatts of power in order to sound their best is a load of crap, unless the speakers in question are really inefficient, which these aren't. Granted, I'll agree that my little 20w amp will run out of steam if asked to produce stadium level volumes, but then I don't feel the need to listen to music at deafening levels in order to enjoy it. You hear stories of people running their system and popping circuit breakers before it's even turned all the way up. Each to their own I suppose.

Lee.

p.s. I found the reason for the highs not being so loud. When using a turntable, I had the phono cartridge loading set wrong.

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I would agree with Loquatious. They will sound better top to bottom with a bigger amp...

i was told by both infinity, and the dealer i bought mine from new, that the emits would be damaged, and warranty would be voided, if i under-powered mine.

its not about "loud" its about high current with headroom...

No matter if one is powering a Quad ESL or Infinity Crescendo, overpowering drivers is the main reason they fail.

also if you are underpowered and blast it you could damage things but just as long as everything is within "reason" it should be fine....just like anything else be smart have fun and enjoy the music...

I drove my cs 3007s with a lepai 2020, and it did just fine until you got 'really' loud.

I then drove them with a lepai 100 wpc chip amp, and they sounded just fine.

I also drove them with a Carver PM 350 (350 wpc @ 8 ohm) and they sounded just fine untill they were too loud for me.

You'll be fine with your little amp, (as I suspect you already know) long as you don't crank it too much.

I really, really miss my 3007's, my brother has them and won't let them go.

Sorry to bump this old thread, but I was just going through my old e-mails. The part number for the midrange surrounds from Tom at myaudioaddiction is Y703. If you want to get the correct ones, he's your man.

Here are the ABCD measurements also from the same e-mail, maybe they will be useful to someone?

Infinity CS-3007

Woofers
A = 8-3/16" (206mm)
B = 7-1/8" (181mm)
C = 6" (152mm)
D = 5-1/2" (140mm)

Mids
A = 4-15/16" (125mm)
B = 4" (103mm)
C = 3-5/16" (84mm)
D = 2-15/16" (75mm)

Lee.

Cool to find such knowledge here at the karma!

I just received my order of eBay mid-range foams for a set of CS 3006's and noticed they did not look correct. I also have a set of Infinity 3-way reference set similar vintage with the polycells's that have the same mid in need of a refoam.

I have had the CS 3007's as well and I love them- however the 3006's with a nice sub sound absolutely amazing its a must hear!

I picked up another pair of these excellent speakers just before Christmas, and just got around to working on them. As before, the dust caps pull right off if you don't bite or cut your fingernails for a week, and use them to get under the glue joint.



Lee.