the real Duke Spinner Posted April 2 Share Posted April 2 I remember having some article on this years ago... Can not find itm .. Anyone remember. ??? 1 Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted April 3 Share Posted April 3 On 4/1/2024 at 10:40 PM, the real Duke Spinner said: I remember having some article on this years ago... Can not find itm .. Anyone remember. ??? From @djk ” Just some notes for both the stock and the (vented) ported LaScala. Porting does not reduce the basic efficiency of the LS, it does however reduce the massive 140hz peak, porting also smooths out the overall response above 100hz, and reduces the dip at 200hz in the stock LS. To get the most out of the ported LS mod you need an EQ similar to the EV Interface A box, it has 6dB of boost at 35hz. You can boost a sealed LS, but that inceases the cone motion, EQ at Fb (port tuning frequency) does not increase cone motion. Less cone motion, less distortion. Any equalizer with a subsonic filter can be changed to do this as well, usually it's just a matter of changing two resistors per channel. I buy used Audio Control EQs from eBay when they go for cheap, the 520 is a nice 5-band piece that is designed to complement standard tone controls and be easy to use. Foam Both versions of the LS benefit from a 2' x 2' x 1" piece of foam behind the woofer. It really smooths out things above 100hz. If you are using subs all the time, you can leave the stock LS sealed and reduce the back volume by about 1/3, and use the foam. This totally reduces the bottom octave, but smooths things out above 100hz. Use non-porus fill to reduce the volume. On axis, the above modified LS will measure flat to about 800hz, and very smooth too. You may use a 650hz or so crossover point on a good horn and driver combo for a nice two-way at this point (or retain the stock Klipsch setup). Thanks are due to Carl Huff for his extensive work and measurements. Stock LS http://cdn.avsforum.com/0/03/037f91bb_DIRAC_LEGACY_01.jpeg Reduced volume stock LS with foam http://cdn.avsforum.com/d/d6/d6ed5986_DIRAC_LEGACY_PADDED_LESSVOL_02.jpeg Carl's measurements were done with a gated measuring system, in a garage, with the door rolled up (open). In room response will show more bass below 100hz due to room gain. In room non-gated measurements show the ported LS to have 7dB more output in the 31hz band (1/3 oct analyzer) vs the stock LS, and 3dB more output in the 50hz band (both without EQ). Using the EQ makes the 31hz band only 3dB down from the average level above 100hz. The contour lines of equal loudness (sounding twice as loud) in the 30hz~40hz region are only 3dB~4dB apart at a level of 90dB, so even without EQ the ported mod sounds like it has twice the deep bass. With the EQ the bass sounds very solid on music, most people would not require a sub (except tor video). But Using a processor like the Waves MaxBass a subwoofer for video is probably not needed either. The 'feel' of bass is mainly from high energy below about 60hz or so, above 60hz there is more of a sensation of 'tone'. The Waves unit takes the fundamental note and generates 3rd and 5th harmonics (an old trick used when playing a piece written for a 16' organ on an 8' organ). With a small speaker like a Heresy this has the sensation of 'tone' when playing those 16' notes, but not the 'feel' (as it has no real energy below 60hz). Using the Waves unit with the ported LS can make you feel the notes as low as 10hz~12hz (when it converts them to 30hz and 50hz) because the ported LS has lots of output there. The Waves unit also has the provision (on some versions) of removing the damaging infrasonics below the Fb of the box (although the recommended EQ does this as well). As a side note The Waves unit makes the Heresy sound like it has bass, but without the 'feel' of the sub 60hz notes. Why would you want this? It works well for apartment dwellers, or wedding dances (those people like the sound of bass, but don't seem to like their teeth rattling).” 2 Quote Link to comment Share on other sites More sharing options...
billybob Posted April 3 Share Posted April 3 Good stuff djk... only so much can be done to accommodate. Gentleman sure helped out a member from Belgium having a small venue Pop festival... Well worth reading his posts... Quote Link to comment Share on other sites More sharing options...
Flevoman Posted April 3 Share Posted April 3 Am I the only one who finds the explanation above insanely interesting but really doesn't understand a thing about it? 😅 1 Quote Link to comment Share on other sites More sharing options...
billybob Posted April 3 Share Posted April 3 (edited) 2 minutes ago, Flevoman said: Am I the only one who finds the explanation above insanely interesting but really doesn't understand a thing about it? 😅 Just one of those things man ... cool! Edited April 3 by billybob Quote Link to comment Share on other sites More sharing options...
billybob Posted April 3 Share Posted April 3 Do a search of the forum... will find examples. Enjoy... Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 3 Share Posted April 3 6 hours ago, billybob said: Do a search of the forum... will find examples. Enjoy... What @Invidiosulus posted above was a copy of one of DJK's posts. He passed away a few years ago. Used to work at a Klipsch dealership in Iowa, later part of his life was an engineer at Collins Aerospace. Brilliant, funny, thoughtful. Would bend over backwards to help you, but didn't suffer fools. He probably threw away/burned more speaker designs than most people have owned. His directness turned off a lot of people. I knew his younger brother and through him, met Dennis. That's how I got turned on to Klipsch. The ported LS still comes back like a ghost. May he rest in peace. 5 1 Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted April 4 Share Posted April 4 With the port mod and active EQ to manage it on the low end as Dennis recommended, my LS are pretty solid to 35Hz. 3 Quote Link to comment Share on other sites More sharing options...
KT88 Posted April 4 Share Posted April 4 When it comes to searching in a forum, google is your friend. Take any site, e.g. community.klipsch.com. Then put the word "site:" in front of it with a colon. Leave a space after .com and enter your search term. E.G.: site:community.klipsch.com lascala vented bass This method is 100 times more productive than the internal search function of any forum I know. Just try it out. BTW I am very inclined to rebuild my 1977 LaScala in this way since my Lascala cases are no longer completely original anyway due to the sanding of the side panels by a stupid carpenter (without asking me) 18 years ago.). It is a very interesting approach. 2 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted April 4 Share Posted April 4 Why port the lascala? Klipsch will soon be selling the ported subs with the DSP and amp included. You can't go wrong. Those things will bring lascalas into the 20s fully engineered. You can use these subs with other Heritage as well. 2 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted April 4 Share Posted April 4 That's definitely true. And I'm also eagerly waiting for them to be released. But we have no idea what the asking price will be. And the expectations are that they won't be particularly cheap 😏. Perhaps for some, this port mod could then be a good alternative. 2 Quote Link to comment Share on other sites More sharing options...
KT88 Posted April 4 Share Posted April 4 51 minutes ago, Flevoman said: That's definitely true. And I'm also eagerly waiting for them to be released. But we have no idea what the asking price will be. And the expectations are that they won't be particularly cheap 😏. Perhaps for some, this port mod could then be a good alternative. …Even if it is true that the 140 Hz peak should be smoothed out. But I would not saw a very recent AL5 into parts, only an old LaScala. 2 Quote Link to comment Share on other sites More sharing options...
KT88 Posted April 4 Share Posted April 4 On 4/3/2024 at 5:50 AM, Flevoman said: Am I the only one who finds the explanation above insanely interesting but really doesn't understand a thing about it? 😅 Put simply, the base plate of the Lascala is removed and an enclosure with two bass reflex tubes is built underneath. This gives you the horn down to approx. real 80 Hz and bass reflex down to approx. 40 Hz. Powerful enough for a large living room, with a little EQ. 2 Quote Link to comment Share on other sites More sharing options...
Woofers and Tweeters Posted April 4 Share Posted April 4 On 4/3/2024 at 6:39 AM, Marvel said: Would bend over backwards to help you, but didn't suffer fools. A few examples are in my sig line. 99.9% of LaScala owners will never change their old speakers, so the port mod is for the 0.1% who might. He came up with the PPSL using four 8" woofers in place of the one 15" too. That is for the 0.001% to try. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 4 Share Posted April 4 Heinz, Yes, the simple way is to make a box about 10 inches tall with ports. (Edit: 10 inches inside height) Four in. diameter x 7 inches seems to be the most popular. Quote Link to comment Share on other sites More sharing options...
billybob Posted April 4 Share Posted April 4 4 inches is right. Same as Chorus 1...making it easier to find port online or hardware store. Even port length 7 inches, coinciding. Quote Link to comment Share on other sites More sharing options...
Full Range Posted April 5 Share Posted April 5 2 hours ago, Marvel said: Heinz, Yes, the simple way is to make a box about 10 inches tall with ports. Four in. diameter x 7 inches seems to be the most popular Are you referring to the bass reflex port? This is the configuration and measurements that I posted of the bass reflex unit on my LS 3 1 Quote Link to comment Share on other sites More sharing options...
Full Range Posted April 5 Share Posted April 5 On 4/3/2024 at 12:46 PM, Invidiosulus said: Foam Both versions of the LS benefit from a 2' x 2' x 1" piece of foam behind the woofer. It really smooths out things above 100hz. I had a similar modification but with the bass reflex box attached ( noting that I did not read the above information prior to my idea ) Just tinkering with different aerodynamic ideas and I ended up using a cone made of styrofoam and glued it to the magnet of the bass driver This may or may not work on a standard LS and as noted it’s in place in conjunction with the bass reflex box 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted April 5 Share Posted April 5 32 minutes ago, Full Range said: Are you referring to the bass reflex port? This is the configuration and measurements that I posted of the bass reflex unit on my LS Ha, that's one of the drawings I made and posted before folks shortened the port lengths. 2 Quote Link to comment Share on other sites More sharing options...
Full Range Posted April 5 Share Posted April 5 36 minutes ago, Marvel said: Ha, that's one of the drawings I made and posted before folks shortened the port lengths. ‘You did a great job on the drawing I just added the measurement's for others to follow, but I did a few more internal modifications to make them better to my personal preference By the way my LS with the bass reflex mod still rock 🤘 2 Quote Link to comment Share on other sites More sharing options...
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