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Dave A

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Posts posted by Dave A


  1. 1 minute ago, joessportster said:

    Same seller then, I assume.  I have no space but thought 2550 was a great deal............2300 is even better :) 

    Yes and they won't be there long I figure.


  2. Just now, joessportster said:

    Thats a Pic of the pair also listed as being in murfreesboro on usaudiomart for 2550.................I posted an alert earlier today 

    I saw your post after I posted but left it up anyway just to let people know John is OK to deal with.


  3. 44 minutes ago, Chief bonehead said:

    I normally don’t suggest going lower than 500 ha but that’s in a cinema setting. For home, I would say not below 400 but it ultimately depends on the all “requirement”. Don’t go deaf on me......

    500hz it will be. You are right to caution on going deaf. Since these arrived my wife complains she has to repeat herself. It is too easy to turn these up and I have had to get a DB meter to monitor things.

     

    42 minutes ago, Chief bonehead said:

    his drawing shows quite the negative expansion rate at the “reflector”. As you plot the expansion you must keep a zero to positive expansion rate thru the turn. Otherwise it will produce some distortion. Just my two cents. 

    On my final plan I went with a circle drawn at the end of the plenum that would contact the sides and back and also the faces of the diverter figuring to keep the expansion rate as high as it could be. Is this a what you would consider a zero to positive expansion rate?


  4. On 7/14/2019 at 1:06 PM, rockhound said:

    Someone needs to buy one of these and test looks killer to me.

    You need to buy two so you can sell me your 904's cheap. As a matter of fact if you wish to not get your hands dirty I haul big hard to handle objects free sometimes.


  5. Yes I did and it does sound good. What was even better was a Japanese fireworks video I downloaded from Youtube. Fantastic fireworks and up to 48" shells so lots of boom which these do rather well if I must say.


  6. So why are you even asking this with a pair of tasty 402's in hand? Are you looking to build out parts you have sitting around? If I owned Cornwall III's AND owned K-402's I would be selling the Cornwalls to fit something good under the big bad horns. Cornwall tweets and mids are quite anemic compared to 402's. If you needed to save space for another listening area my choice would be to sell the Cornwall III's and find a good set of Chorus speakers to upgrade and use the money left over for something else. If you are


  7. 2 hours ago, PrestonTom said:

    Dave, My friendly advice is that you might be over-analyzing this. 

     

    My memory is that an engineer from Klipsch mentioned that 1) some of the versions of the bass bin did have reflectors and it was later found that these were not necessary and were then dropped from the design. 2) that there are two views - either  thinking about the waveform traveling down the path as analogous to a "ray of light". This is the Bruce Edgar way of looking at things and hence the "need" for a reflector. In contrast, the other view is to think of the waveform as fluid in a pipe and the requirement is that the cross-sectional needs to continually expand. So with this view, the reflector is not necessarily needed. This later view was favored by a certain engineer at Klipsch.

     

    Regarding the need to lower the crossover point: I think JWC is correct. Extending the bandwidth downward is asking quite a bit from the 1132 driver. Of course, this could be verified by some distortion measures if anyone is willing or able to make them. 

     

    I think you are viewing your FR measures (with a low pass roll off at 400Hz or so) as a glass half empty rather than half full. It is fine to have a low pass roll off from the bass bin of 3-6 dB at the nominal crossover point. It simply becomes part of the net (overall) crossover. Although you may want to think carefully about the steepness of your crossover filtering. I saw nothing in FR plots that indicated a major problem. Yes, you will need to add a few PEQs to knock down some peaks but that is not a problem (I assume you will be using DSP, if not, I hope you consider that strategy). 

     

    Good luck,

    -Tom

    Not analyzing as much as looking for best practices from people who have been there before. It is a shame there is no way to visualize sound waves as they propagate and see what works best. They have FEA software for many things now but I don't remember reading of any for sound waves and I expect the market of potential buyers is to small for programs being written for it.

      Really I am quite happy with the results but if there is improvement beyond electronic tinkering to be had I am interested. You never know until you seek the answers and at some point in time someone has to try it too. Sound propagation seems to be one of the fields that does not have specific rules laid down with proven singular best practices and so we see all the competing designs and no clear cut winner.

     I regard Paul as a genius having come up with what he did and I assume some math and lots of intuitive engineering insight to do what he did before computers and software was around.


  8. 4 hours ago, jwc said:

    Remember, the reflector is an attempt to obtain "slightly more horn loaded material" after 300Hz.

     

    image.thumb.png.fa20c527b57bcf17d8b5131c8713e566.png

    Actually what I would do would be to open the cad file and derive precise dimensions and prebuild the whole thing and then make a removable panel on the back side which would allow me to change things around at a whim. By the way on the Edgar attachment I never had a page 13.

      This does make sense in that it does more uniformly continue expansion where the straight dumping from the plenum end to around the bend does not have that as is.


  9. 15 minutes ago, ClaudeJ1 said:

    Since JWC and I are strong on the idea that potential natural ACOUSTIC improvement at the more critical 300-500 Hz. range by adding reflectors, thereby mating with the upper end, I would say hold off until you have exhausted all the improvements that can be made with PEQ FIRST! Then go back for a second look if those other things don't work for your ears. I think the curves you posted look very encouraging to going with the PEQ route with your Xilica.

    Yes this is my plan. I might still pursue a better splitter or diverter  after I get things set with the xilica just to see. 


  10. 2 hours ago, glens said:

    Also, you could "track-thin-kerf-jigsaw-cut" the back panel out near its perimeter, mount it to a new panel and mount that back onto the box with screws.  (Just thinking out loud how I might spend someone else's time and money.)

    I had thought about cutting a square panel out of the back side that could be mounted back in with various sizes of deflectors. I really only need that section to be removable. The idea of a curve on the deflector on the backside and the inside corners to make sound "flow like water" with fewer ripple inducing disturbances is something I had discussed before but seemed to draw no interest or definitive answers. With limited knowledge but thinking practically about things it just seemed to me that sound could handle to some degree like water  or air flow and curved transitions would enable more uniform flow with fewer "eddies" in it causing audio problems. I see tons of sharp angular transitions in speaker cabinets though. I would think curved corners would also break up any standing wave problems these S-MWM's might have.   


  11. 32 minutes ago, Ziggurat said:

    less like hifi and more like owning a bunch of musicians that do what I tell them..... 

    Absolutely. The goal you are pursuing is well worth the trouble. When you get it all dialed in watch the faces of your fellow music lovers when they first hear them. I buy fix and sell old Klipsch and I NEVER let them hear the big box until we are all done and they agree what they bought is nice. Then I let them hear much better than nice. You listen to pro gear set up right as your daily music source you can forget what it sounds like to someone who has never heard it before. Familiarity does not breed contempt but you can forget how thin all the other stuff is in comparison and the look on customers faces when the big boys fire up reminds you of that.

    34 minutes ago, Ziggurat said:

    I sense my endgame in sight with this system...

    Darned right. Familiarity will never breed contempt for what you will have but it is nice to have new listeners remind you once in a while what you really DO have. I never let buyers hear my personal system until they have decided they like what they came to hear and buy them. THEN they can listen to what is not for sale.

    • Like 1

  12. Also a bump on what the lowest practical hz limit is on the 402+1132 combo. I have seen the literature on various drivers but asking for practical real user experience or tech advice from someone who knows.


  13. Scrolling back through this thread to reply to someone and I was thinking how hard it is to get information sometimes. I had discussed a splitter with the La Scala being bigger and having an arc to it with with corner rounds on the outside internal corners also figuring sound might behave like water and rounded transitions would create less "turbulence". Among those who responded the idea was it generally poo pooed and that is why I did not consider this for the S-MWM. I had also posted pictures of the splitter before install but I guess no one caught that to tell me other wise. There were also comments to the regard that PWK did not have splitters in the MWM and so they are not needed.

     

       So what I am doing today is trying to get definitive best practices for the splitter and the outside corners. Due to the size of the cabinet and the degree of difficulty in holding it all squarely in place I had to make the back to be glued in and change is not going to be simple or easy. I am willing to consider doing this is it will bring about significant improvement. I would like to hear from those with real practical design knowledge and or hands on build results they can tell me about that incorporated this kind of idea. It is possible to make this from say 1/8" formed aluminum and screw these things in from the front without removing the back. 


  14. 6 hours ago, ODS123 said:

     

      Why are you having such a hard time believing that MDF is a better choice when every speaker manufacturer under the sun (minus one or two) who uses wood uses this material?  I find the claims that it is a better choice because of rigidity, consistency  and sound characteristics are more believable than your assertion that it is chosen simply to save a few dollars.   Heck, if spending the extra bucks for plywood gave Klipsch a bragging right they would certainly have chosen it  and made hay about it in there brochures etc.  But they didn’t because they know better 

     

     And you still haven’t addressed my question about your extraordinary concerns about water resistance. What other component that is part of our hi-fi set ups was ever engineered with water resistance in mind? Not our amplifiers, turntables, tape decks, flatscreen TVs, etc. None of these need to be water resistant so why would speakers? 

    Say if you are ever in the area stop in and hear a real system. Then we can migrate to the ridge top for a little target practice, carcinogenic bar-b-cue and Tannerite.

    • Like 1

  15. Looks like a home build. Construction inside the mid horn bin is not Klipsch and the mid horn driver and crossovers are not either as far as I can tell with the grainy picture. Basic box looks good though so the right components will give you a great speaker.

     

      No telling what your woofer will be. I have had K-43's and K-33's, generic Eminence (more than one type)  and speakers marked "Taiwan" for the brand name and model number.

     

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