sound boy Posted January 29, 2003 Share Posted January 29, 2003 I have a pair of Pro La Scalas and would like to add more bass. I was thinking of adding one ksw 15; is this enough to accomodate? Thanks Quote Link to comment Share on other sites More sharing options...
Q-Man Posted January 29, 2003 Share Posted January 29, 2003 NO! You need more sub then that. Start reading the post under Subwoofers. I would say that the bare Min. would be a Sunfire Signature, Velodyne HGS-18. Above them. I would start with the SVS dual Ultras. I'm sure the EAR will add a few. Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted January 29, 2003 Share Posted January 29, 2003 The opinion of many people here on the forum is that the KSW subs are a little on the "sloppy" side of things. I doubt that A single KSW-15 would be able to keep up with the speed of the LaScalas. Peace, Josh Quote Link to comment Share on other sites More sharing options...
HDBRbuilder Posted January 29, 2003 Share Posted January 29, 2003 Sound boy...do you mean you want louder bass, or deeper bass? If it is deeper bass you want...you can get a bit more of that by going from the k-43 woofer in your pro LaScalas to the k-33 woofer...if it is louder bass you want, then the k-43 should stay in them. Remember, that if you change over to the k-33 woofer, you will need to adjust your crossover...and limit the power going to the lascalas...the k-33 goes lower, but can't handle as much power as the k-43 can handle! Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 29, 2003 Share Posted January 29, 2003 I read, on one of the other speaker forums, added about 4 cubic feet of volume to the back chamber on the LS and port it, that you pick up a fair amount of bass. This guys solution was to open up the back camber to the mid range horn area, seal the back and the port it. I wasnt willing to destroy my LSs but there is no reason why you could not remove the bottom plate and build a new 4 ft^3 box on the bottom. Has anyone tried this? Jim N Quote Link to comment Share on other sites More sharing options...
michael hurd Posted January 29, 2003 Share Posted January 29, 2003 I wouldn't recommend that from my limited knowledge. From everything I have read about horns is that the rear chamber load must match the loading of the horn itself, otherwise non-linear motion of the transducer will result, and possibly damage the woofer, when driven to higher levels. If there is more resistance in the throat of the horn, then more excursion rearward is possible. If Q-man has more to say about this, then regard his opinions, as he is the basshorn man. Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 30, 2003 Share Posted January 30, 2003 Both Altec and JBL built many front horn loaded rear bass reflex loaded systems. This is not to say the that k33 is the optimum driver for this arangement. Jim N Quote Link to comment Share on other sites More sharing options...
djk Posted January 30, 2003 Share Posted January 30, 2003 I'm the one that suggested porting the LaScala. It works best with the K43 woofer, although the K33 is OK. If you have a pro set you can replace the removeable back board across the HF section and should you not care for the mod, replace this board back with the original. No one that has tried this mod has felt the need to go back to stock. Do a search in Audio Asylum on 'djk' and 'LaScala' if you want details. Quote Link to comment Share on other sites More sharing options...
jnorv Posted January 31, 2003 Share Posted January 31, 2003 djk, do you have any opinion on the optimum extra size for the "base bin". I plan on building a box that I set the LS's on, so the extra volume can be anything that I like. Using the T/s parameters, it looks like a 7 ft^3 box is about right. Jim N Quote Link to comment Share on other sites More sharing options...
djk Posted January 31, 2003 Share Posted January 31, 2003 7 cu ft (net) is about right for a K33, you can tune it just like a Cornwall. The way I do it with a K43 does not change the size or look of the LaScala. You can also tune it to go deeper than the Cornwall. Trying it out with the extra volume in the form of a riser base really is the 'no pain' method. Quote Link to comment Share on other sites More sharing options...
jnorv Posted February 1, 2003 Share Posted February 1, 2003 djk, do you have a thought for the difference in sound if I invert the LS's and put the additional box on top? Makes it much easier to test. Don't have to lift the LS's and it makes it easier to change drivers. This arrangement is close to 1/2 of an Altec 210. I have a pair of 515B's that should also be a good match for a system like this. Second question. What are your thoughts on going bigger on the volume of the cabinet and retuning to get lower bass response? Must be some kind of trade off. I am a firm believer in the 1st law of Thermodynamics-you can't get something for nothing. I am not using the LS's mid/high drivers. I will use 511's with 802's, mounted on top of the stack. Jim N Quote Link to comment Share on other sites More sharing options...
djk Posted February 2, 2003 Share Posted February 2, 2003 The Altec 515B will not fit in a Klipsch LaScala, it is 15-5/16" wide, the LaScala is only 15.000" I made my LaScala clones 15-3/4" wide so I could use any 15" without worry about the fit. Even then, an Altec 421 and later 416 won't fit. http://www.lansingheritage.org/images/altec/catalogs/1975-pro/page11.jpg The requirements for a horn woofer and a vented woofer are at direct odds. The lower the Qts for the horn, the better. The higher the Qts for the vented system, the better (he maximum here being about Qts=0.4) The optimum Qts for a combination horn/vented system would be a Qts=0.312 (taking into consideration the source impedance as well). The Altec 515-8G would be much better suited for a combination horn/vented system, it has the 16" frame. Quote Link to comment Share on other sites More sharing options...
erikjohn Posted February 4, 2003 Share Posted February 4, 2003 Keep in mind what you gain in lower Freq you will lose off the top. I wouldn't mess with em', just add a sub, you'll be happier in the end by keeping that tight bass kick that the LaScala has. EJ Quote Link to comment Share on other sites More sharing options...
Colin Posted February 4, 2003 Share Posted February 4, 2003 Like so many full range loudspeakers, the big old LaScala horns do have high output and fairly flat, quick, but not punchy, bass down to about 40-Hz. The punchy sound that we like is most often heard with bass reflex cone loudspeakers, often tipped up in the lower regions. Or it is heard from moderate price subwoofers, which have prodigious output in the 40 to 80-Hz range. It is a shame that we have to dig to find the frequency response curves for subwoofers. They would tell you where the sub is most capable. A modest sub, like the KSW series, will add some boomy muscle to the mid-bass areas. This can be very nice, for the low cost of this improvement, especially for movies. It will add some punch, but can easily overwhlem the accuracy of the mid, upper-bass and mid-range regions. (The LaScala sound more like live acoustic bass, then the techno stuff we get nowadys.) A deep bass subwoofer, like the SVS tubes, will be the best match for music. They have most of their output at levels only expensive, high performance subs can reach. They can provide a flat response below where the LaScalas can not go. The RSW reference series will provide a lot of mid-bass punch, which makes movies great, but they can not reach as deep as the SVS tubes. See Product Review - Subwoofers Under the Christmas Tree - December, 2001 at: http://www.hometheaterhifi.com/volume_8_4/subwoofers-12-2001.html Quote Link to comment Share on other sites More sharing options...
Q-Man Posted February 4, 2003 Share Posted February 4, 2003 I have to side with EJ, and Colin on this one. Opening up the LaScala that way is simular to turning it into a Cornwall, at best a poorly designed back loaded bass horn. Quote Link to comment Share on other sites More sharing options...
Walter Creati Posted December 18, 2003 Share Posted December 18, 2003 Hi djk, I live in Italy and it is the first time I write in this forum. I have a pair of LaScala's (a bit modified design as you can see) and a pair of Altec 515B 15"'s and a pair of 421 8H's. The 515B sounds faster and louder, ma with both drivers the bass is dry and not deep. So I have thought of your reflex box to add to bottom. What internal volume do I consider for the 515 (and for the 421 too if you think this is a better choice) and for the dimension and lenght of the reflex port? I use biamping (Audio Note Kit one for the highs and Adcom for the bass), a passive line filter only for the bass (I lower the coupled capacitor for the highs), and an Altec 288 with 311 horn. Thanks in advance Walter Creati Quote Link to comment Share on other sites More sharing options...
IndyKlipschFan Posted December 18, 2003 Share Posted December 18, 2003 I have a pair of Pro La Scalas and would like to add more bass. I was thinking of adding one ksw 15; is this enough to accomodate? At the risk of all of the stereo guys beating me up in here or the SVS guys saying heck go get the SVS sub..(these are audio home theater subs, not live sound application subs in here as suggestions... First off, A great DBX 1/3 octive Stereo EQ might "find" all the bass you need. 299.00 fix. I still have 2 pro La Scala pairs.. I also agree with you especially with todays music. Todays music is much more dynamic and people gotta hear the bass and synth and drums too. Origianally designed for GOV Rockafeller political speaches so he could have em set up in no time from a train station someplace (I know we all sweetly remember the La Scala opera house....This speaker was designed mainly for the VOICE to carry over large crowds read Pauls Book. I am sure now I have offended everyone.) This is more true especially with the pro La Scalas woofer in the dog house or "W box" as we called em in the midwest here. LOL It does not go asl low as the K 33 regular one, but def will play louder and longer safer... I wish the La Scala bottom end was like the Cornwalls or the Klipschorn. 38 and 33Htz if I remember right off the top of my head and the La Scala is what 53 ish?? Most people will argue that in pro sound you will never hear it especially at very loud volumes. While I "semi agree" with this point unless your also using your La Scalas for Band DJ/KJ work in a large room...at some hotel or bar.. How will you let em out n breathe to see at these levels? In College we used a dual 18 inch JBL sub cabinet with something like 1000 watts of Crown amp power in front of the band Dj setup. This provided us a gap between us and the audience gave me something to stand on occasionally..LOL This seemed to work out great. No not to 20 htz but more like 30-60 if I remember right?... to add the "thump" to the DJ music. Today JBL has a Crown amp built into a single 18" I would suggest you look into. I have a feeling this would be the perfect match for what your looking at. I am hoping the guys at my local GUITAR CENTER or SAM ASH store will let me rent to buy one overnight sometime this spring to find out. The JBL/Crown MP418SP is a compact, powered, single 18 inch, bass-reflex subwoofer system. Designed for portable applications, the MP418SP includes heavy-duty, 3 inch casters and ergonomically positioned steel carry handles to facilitate transport. A dual-channel Crown amplifier with signal processing is incorporated into the system. While one amplifier channel (the Internal channel) is dedicated to powering the internal 18" VGC woofer, the other channel (the External channel) may be used in one of two ways: In the Sub + Sat mode, an MP418SP may be used with a full-range, passive speaker for a single channel, two piece system. The external amplifier channel powers the satellite. In the Sub + Sub mode, the external amplifier channel is used to drive the MP418S (a passive version of the MP418SP). Stereo, high-passed line-outputs are provided to drive powered satellite speakers or an external amplifier / speaker system. Features: 600 watt, 4 ohm VGC (Vented Gap Cooling) 18 inch low frequency transducer for unsurpassed performance. Powered By Crown Dual channel amplifier with 660 watts RMS per channel into 4 ohms or 400 watts RMS into 8 ohms. Flexibility - May be used with passive or powered satellite speakers. Enclosure constructed of 18 mm plywood and coated with JBLs exclusive DuraFlex - a rugged, advanced, poly-urea finish. 16 gauge, hexagon perforated, steel grill. Heavy-duty steel carry handles. Heavy duty casters mounted on the rear of the enclosure for easy transport 35 mm pole mount receptacle. Specifications: Frequency Range (-10 dB): 36 Hz - 150 Hz Frequency Response (±3 dB): 40 Hz - 120 Hz Nominal Impedance: 4 ohms Crossover Frequeency: 120 Hz Total Harmonic Distortion: 1 kHz rated power, 0.5% or less true THD from 20 Hz to 20 kHz http://www.samash.com/catalog/showitem.asp?ItemID=21921&TempID=6&Method=3&CategoryID=109&BrandID=0&PriceRangeID=0&PageNum=0&DepartmentID=5&DepartmentKeeper=5&pagesize=10&SortMethod=6&Word1=&Contains=&Search_Type=SEARCH&GroupCode=nonetodaythanks Again not to 20 HTZ, but if you get solid 30 something as you know and feel in the K horn and Cornwalls... Def low enough! And more important inside or out safe to use with your Pro Lascalas night in, night out. I just wish for all purposes the La Scalas did go to 33 like the K horn then we might have a great A vs B comparison. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted December 18, 2003 Share Posted December 18, 2003 I agree with djk... and the idea of putting the LS on top of the ported box is a brilliant idea! the LS horn has a low freq cutoff of around 60 Hz, if I remember correctly, that means that you really can't force the enclosure to go lower than about 5O Hz or so without modifications. This is a just a guess, but I think that the easiest approach (which will not harm the original LS cabinet) is to reflex port the back chamber by sitting the LS on another box with the bottom cover of the back chamber mated to an appropriately sized and tuned box containing the port itself. This will unload the pressure on the front of the driver facing the horn to a degree and subsequently lower efficiency and lessen the mid-bass punch but should result in the ability to reproduce bass notes lower than the horn by itself using the same driver. Note that the bottom "ported unit" should only be about 2 or 2-1/2 cu ft. This would be somewhat like a Altec A-7 (which has a direct horn with a cutoff at around 80 Hz). I would guess that the performance would be about the same, but don't hold me to it. Due to the extremely short length of the LS horn itself, I wouldn't expect that the amount of resistance that the driver is pushing against would be drastically effected by enlarging the back chamber area by a couple of cubic feet as long as the port area itself is kept reasonably small so the horn is not completely unloaded. The port size itself can be regulated for testing by a screw attached cover, like the A-7, etc. The K33-E woofer is a bit "sloppier" than the Altec 515-8, but should go lower (but may lack some of the punch). also if it doesn't work out, you can simply put the botton convers back on and burn the ported boxes... I would love to hear about this experiment if you do it... Go for it, dude! DM Quote Link to comment Share on other sites More sharing options...
Walter Creati Posted December 19, 2003 Share Posted December 19, 2003 Hi D-Man and IndyKlipschFan, thanks for your answers. In the past I tried some subs, but it was almost impossible to find the right position for it. During these holidays I'd like to build two vented boxes. I hope to report positive impressions. Merry Christmas Walter Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 19, 2003 Share Posted December 19, 2003 Hi Walter, Welcome to the forum. I posted this drawing some time ago for those wanting to try this mod. This will give more of an idea what djk had written about. Marvel Quote Link to comment Share on other sites More sharing options...
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