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KP301 port mod


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ive seen the mod for extending ports on the chorus, anyone ever do this to PRO models like the 301ii? what should the length be?

 

looking at the 301 & 301ii specs,  the 301 goes a lot lower than the 301ii on paper,  i think the original 301s show 36hz but the 301ii show 45hz like the chorus.  why would klipsch raise the bass freq on the 2s & what makes up for the difference since both models use the same woofer & cabinet dimensions look pretty close.  

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3 minutes ago, EpicKlipschFan said:

ive seen the mod for extending ports on the chorus, anyone ever do this to PRO models like the 301ii? what should the length be?

 

looking at the 301 & 301ii specs,  the 301 goes a lot lower than the 301ii on paper,  i think the original 301s show 36hz but the 301ii show 45hz like the chorus.  why would klipsch raise the bass freq on the 2s & what makes up for the difference since both models use the same woofer & cabinet dimensions look pretty close.  

If you can, take a look at any difference between both models ports length, if any.

Experiment...

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Just now, billybob said:

If you can, take a look at any difference between both models ports length, if any.

Experiment...

 

from what i can tell, the ports are just holes in the front board, just like on the chorus.  the mod for the chorus extends them a certain length, i think i remember 6-7" but im probably off on that.  

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2 minutes ago, billybob said:

Think Chorus mod length is around 7 inches.

 

yeah thats what i recall... just wondering if it would be different for the 301 since the cabinets are different dimensions, but maybe they are the same volume?  

 

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Just now, EpicKlipschFan said:

 

yeah thats what i recall... just wondering if it would be different for the 301 since teh cabinets are different dimensions, but maybe they are the same volume?  

 

Ca not say but, likely close enough volume to try using a roll of heavy paper to try a temp...

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  • 9 months later...

I know this is a super old thread, but I’m resurrecting to ask about my 301’s after following the advice in this thread. These are audyssey results from AFTER adding 4x6” port extensions. I’m lucky if the response doesn’t fall off a cliff above 80ish hertz. Before the mod, I was lucky if it was more like 90 or even 100ish. This can’t be normal.


Also, these big dips on the left speaker seem extreme. (I’ve gotten rid of the 2k dip audyssey puts in already)
 

they’ve had at least the big capacitor replaced. Could it be time for a complete overhaul on the crossover? 

 

Cheers

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5 hours ago, revrseat70 said:

 Could it be time for a complete overhaul on the crossover? 

  replace the capacitors ,  remove  all modifications ,  the speaker was designed  for optimal performance by  Engineers  

 

,  buy a new Klipsch capacitors kit from  JEM   , open  the box , check the cabinet sealing , are the drivers original  ?    are the crossovers original or modified    ?   what is the condition of the woofer suspension  ?   

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On 1/25/2023 at 12:20 PM, geoff. said:

Silly question, since you mentioned Audyssey, is the DSP bypassed?

These are the results audyssey gathered not rew measurements while running DSP. So while the results could probably be more accurate, this is what I have to work with. 

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On 1/25/2023 at 11:06 AM, OO1 said:

  replace the capacitors ,  remove  all modifications ,  the speaker was designed  for optimal performance by  Engineers  

 

,  buy a new Klipsch capacitors kit from  JEM   , open  the box , check the cabinet sealing , are the drivers original  ?    are the crossovers original or modified    ?   what is the condition of the woofer suspension  ?   

I bought these last year. The woofer design looks different but everything else physically looks the same. By design I mean one is silver with the model Stamp K48 and the other is black with the Klipsch emblem. Shape and dimensions look the same. 
 

the squawkers are identical and the tweeters are now SMAHLs. 
 

The one with the huge dips has a 30.B crossover, while the better looking graph is from a 30.A crossover. 
 

the cabinets seem to be in good shape. I’ve added bracing while I was adding the extensions. 
 

but I want to be clear, the bass extension fell off a cliff 20hz higher before the extensions. Tons of slam, just no depth. 

Edited by revrseat70
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