New Speakers in the Abode: Upgrade Advice Sought

[Yoder]

While dinking around on the Web the other day I found a pair of Klipsch Chorus speakers on Craig's List just down the street. The guy runs a local radio museum and purchased some really nice old refurbished radios (the ones that stand 4' tall) and the Chorus speakers at an estate sale. He didn't want the Klipsh and so let them go for a song.

From what I have read the Chorus are direct decedents of the Forte except they have a 15" subwoofer. The ones I got are almost like new, with an oak veneer. I peeked into one of the bass ports and it looks like they have been refreshed in many ways: new wire, the crossover has some new parts including some cheap electrolytic caps  Anyway, the caps will definitely go but I am curious as to what gauge of wire to use? I have read that when going to the woofer 16 gauge wire works best? What about the rest of the wiring? Any ideas/input would be greatly appreciated.

The first piece I played on them was Bach's organ piece "Tocatto de Fugue..." Wow. Then played some Ben Webster with equal satisfaction. Right now I am a floor above and the Dead sound great. Once I test my Foreplay III, and Paramounts then I shall plug them into the Chorus' (yes, it has taken awhile to get the BH system going but with crappy health and all it is to be expected. I did finish the Eros about 8 months ago and it fired right up and now is getting daily use.)

Thanks for any advice in advance.

[Brillo]

Check out Bob Crites' website: critesspeakers.com.  Lots of Klipsch upgrades. Maybe you'll get some ideas. I ordered crossovers a couple years back and internal speaker wire provided was probably 12ga, maybe 10ga. It's probably easy to access within the cabinet, so experiment.

[bobster]

Second the Bob Crites site.  Replaced the crossovers in my Heresys with his product.

[Yoder]

Yea, I am familiar with Crite's gear and will most likely use his tweeter mod as one of the first things I do.

From what I have seen and read, most of the insides of older Klipsch speakers are not painted. I noticed that my Chorus' have been painted black which got me to wondering. Has anyone tried painting the insides of any speaker cabs with the type of black paint that dries with a very rough surface? Or, has anyone painted the insides with the rubber like black paint? I am wondering if the rubber like black paint would work to reduce any vibration and/or reflections? Insights? Logical excursions? Any obvious advantages of either paint type or disadvantages?

[RPMac]

Don't know about the paint, but wouldn't think it would help much with box vibrations. But I do know what worked on my Heresy II's.

I cut strips of good quality 3/4" plywood 1 3/4" wide. I glued and screwed them in a '+' pattern on the top, bottom, and sides (cut to be press-in fit). The speaker terminal plate with crossover on it is in the center of the back, so I did a '#' pattern.

At the time, I had my mother-in-law's pair of Heresy II's to compare...night and day difference. Until then, I never realized how much of the "bass sound" was actually "box vibration".

Another big improvement is to coat the back of the horns with plumber's putty or rope caulk to reduce woofer vibrations thru the horns. You won't be disappointed with these mods.

I also have the crossover outboard and replaced all the caps.

[Paul Joppa]

Speaking technically about damping:

To be effective, a single layer of damping substance must have a total bending stiffness similar to that of the material being damped, as well as a loss factor comparable to that stiffness. If you are damping a structural material (such as plywood) that almost always means the damping layer must be of comparable thickness - paint will not do the job. For speaker panels the traditional sand-loaded roofing tar is normally applied 1/4 to 1/2 inch thick.

(As an aside, damping materials are usually described as being rubbery at low frequencies and glassy at high frequencies; the best damping happens in the middle. So you need to know the stiffness at the target frequencies, which can be very difficult to guess by poking it!)

Constrained-layer damping, between two sheets of structural material, is an entirely different thing which I can't fit into a post. And none of the above is meant to claim that damping actually improves the sound - that's another long and complicated discussion...

[corndog71]

I used a product called "No Rez" which was developed for lining the insides of speakers.  http://gr-research.com/norez24x27sheet.aspx

It made a significant difference in my Heresies. 

I'll have to dig up the pics to post them.

[Jim R.]

You may save yourself some money and look for a generic bituminous asphalt and open-cell foam sheet damping product such as used to dampen the cases of computers for use in low noise environments (think recording studios). I got some sheets of no-rez once and compared it to some of the computer damping material I had and could not tell any difference at all. Looked to be the exactly same stuff and came in the same size sheets.

Also, dynamat extreme works really well on the horn bodys.

-- Jim

[Paul Birkeland]

For speaker panels the traditional sand-loaded roofing tar is normally applied 1/4 to 1/2 inch thick.

That sounds incredibly unpleasant!  Doesn't that stuff take a few weeks to outgas? 

[Paul Joppa]

PB, I believe you are exactly correct on both comments. Normal practice in the old days was to do the bottom panel, let it set up for a few weeks, then rotate the cabinet 90 degrees to do the next panel... Plus the outgassing has (IIRC) been known to soften certain adhesives used in the speaker drivers.

[Yoder]

You may save yourself some money and look for a generic bituminous asphalt and open-cell foam sheet damping product such as used to dampen the cases of computers for use in low noise environments (think recording studios). I got some sheets of no-rez once and compared it to some of the computer damping material I had and could not tell any difference at all. Looked to be the exactly same stuff and came in the same size sheets.

Also, dynamat extreme works really well on the horn bodys.

-- Jim

Yea, I have quite a bit of open-cell foam and I just got some 3M anti-vibration rubber sheets (not cheap and seem to be a lot like the Dynamat Extreme) that I am going to try putting on the "spider spindles" (that's what they call them on resonator guitars and I not sure what they call the metal going from the magnet to the rim of the speaker cone.) of some other speakers, and on the horn body of the Chorus'.  Anyway, I got four sheets of the stuff that I want to try it on various components.) What I am curious about, and maybe nobody knows but I know that there are some good brains around here, is if a rough inside of a speaker cab can affect the sound. I am thinking of the dimples that B&W uses on their bass ports and the dimple of affect on golf balls, though I have no plans of driving them down the range.

I pulled the crossover of one out last night and it is anything but stock. All looks good except for the electrolytic caps instead of film caps. Whoever did it also painted the inside black and used 22 gauge wire throughout. I will definitely replace the wire, and caps initially, then will slowly migrate over to Crites. This is a good kick in the ass to get the BH Para's and Foreplay online so that I can audition them with the Chorus. I am pathetically slow sometimes...

[Paully]

I had a Chorus II that I upgraded with Crites crossovers, so I was a fan.  Letting those go was a hard decision, and though I like my Altecs, the difference wasn't as huge as I had been led to believe.  Those Klipsch are a great way to do high efficiency cheaply.  I never dampened my Klpisch horns, didnt seem like they needed it.  I did on my Altecs.  Can't say it made much of a difference to my ears.  When I took the horns out and tapped them they did ring.  But bolting them in place onto the speaker really seemed to kill almost all of the resonances.  I dynamatted them anyway.

Regardless, I just wanted to echo the sentiments that the upgrade crossover from Crites is the way to go.  Didn't do any of the other upgrades he offers.