Chorus 1 question
- Thread starter stereoud7
- Start date
"I have some Chorus I's from '88. Been saving up for the big B.C. upgrades, stumbled upon this post and thought hmmm cheap experiment. I walked over to our shipping dept., grabbed a 4" mailing tube, measured the OD. Wouldn't you know it... exactly what I needed. I cut two down to 7" in length, wedged them into the ports of one of the speakers and put in a song with some pretty heavy bass. It took all of about 3 seconds to confirm significantly more bass coming from the speaker with the modified ports. Now, is 7" the ideal length and is a mailing tube the ideal material to use? I don't know, but it was affordable and it works! Spread the word."
https://community.klipsch.com/index...s-pretty/&page=2&tab=comments#comment-1925670
https://community.klipsch.com/index...s-pretty/&page=2&tab=comments#comment-1925670
moray james
Super Member
you can place damping material which works well at low frequencies into the upper section of the cabinet above the woofer but you need to contrive that it stays there by some convenient means. good old home fiberglass insulation works about as good as there is for this application. You can also place some damping material below the passive on the bottom of the cabinet as well and gravity will keep that in place. What is critical to achieve/understand is that you need to keep the volume of air between the woofer and the reflex vents or the passive radiator open and free to resonate as that is what acoustically couples these two devices. The rest of the cabinet volume can be damped.I'm about to mount some bass tubes in my speakers. I want to check that they are sopposed to be 7" long.
also..... Should i put some damping material/fluff.... not sure of the terminology into the speaker. it has none.
thanks
Seven inch vent is a good length. Any tube between 6 - 7 inches in length will work just fine and the tube does not have to be overly rigid to work well so thin wall paper is no problem. this makes it easy an cheap you you to experiment with tube lengths of your choice. Shorter than seven inches will not go as low and longer the woofer will not drive as effectively. That means your working range is between zero and seven inches in length. Hope this helps.
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moray james
Super Member
Sorry I was going onward to the Chorus ll, never the less the exact same conditions exist within the enclosure whether passive radiator or reflex vents they (the two methods of damping) are the same action and the open volume of air between the woofer and the vent(s) or passive must be maintained.
So in a Chorus you could place some fiberglass below the vent area on the bottom of the cabinet and then fiberglass damp the cabinet area above the woofer.
moray james
Super Member
the Chorus ll with a fifteen inch passive radiator mounted to the rear of the cabinet can be tuned lower in a similar fashion to the reflex loaded Chorus, where the reflex vents are lengthened to lower the tuning, with the passive dead weight is added to the passive assembly about 2 - 2.5 ounces will make a nice improvement in bass extension. This is easy to experiment with to add and to remove so please to those who will immediately complain the speaker will be ruined the weight is just as easy to remove as to add on.
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