sootshe

When I built these I installed the centre brace, but that didn't cure the resonance coming from the bass bin, so I doubled the side walls & also the rear panel & that completely eliminated any resonances coming form the bass bin.

The top & bottom pieces of wood aren't braces...they are just strips of wood for the grilles to attach to. . The centre section is the actual brace. I built these.

Thanks to all......got a lot of useful info from the link to the old thread.

Hi all, Looking to put together a set of Deans crossovers for a pair of Belles. I've searched everywhere on this forum for a thread I believe he created - " Building the AA"s", but can't find it anywhere. Can anyone point me in the right direction? Also, does he still make crossovers? Many thanks, John

Here's the link to the Altec forum.....unfortunately the pages take forever to load, they must have issues with their web site, but if you're patient there's a wealth of info on there. .http://www.hostboard.com/forums/f700/altec-users-board.html

Been a bit tied up on other projects lately, but thanks for your help....I appreciate it.

Hang on to those 515's & the 288's. They are some of the best drivers you will ever get. Best to talk to the Altec Users Board guys to pursue your queries, as they will have all the answers. Can't seem to get on there at the moment to give you the link, but just google - "Altec Users Board"

Sorry....forgot to add the TS parameters.....see attached in post 1.

Hi all, I have a set of 5.3ft3 cabinets with 2 x 4" diam x 6" long ports that I want to install some CW1526C's into. I ran sims in Win ISD & that size cab seems to work OK, but I can't seem to get the venting calculation to work properly. TS parameters for the 1526 attached. Can anyone run some sims for me & tell me what the best port dimensions are for the 1526 drivers in that size cab? I would like the tuning frequency to be as close to the tuning of the Cornwall cabinets as possible.....not sure what that tuning frequency is. Thanks. CW1526C WOOFER DRIVER PARAMETERS.docx

Here's a couple: https://www.tortugaaudio.com/ http://www.iconaudio.com/main-products/passive-and-passive-r-pre-amp/

Curves & specs don't always tell the full story.....let your ears decide. There's a reason that JBL is more expensive than other drivers. This may account for the reason they & another similar brand was used in recording studios & PA systems world wide & why there is a resurgence in so called older technology. You can't go past good old fashioned engineering principles. Not everything that is new is better.

Hi Dean, Mike Lenehan from Lenehan Audio on the Gold Coast in Queensland made them for me.....nice job. I was originally going to go for North Creek, but they are no longer available. Mike winds these by hand - 3mm copper.

North West Queensland.....about 4 hours west of Brisbane. Good to see another Aussie Klipsch fan.

Some pics of my new crossover build for a set of Belles I'll be putting together. These are AP12 - 500 & AP15 - 6000 design with upgraded components. As you can see I've used all Sonicaps in the bass section & Jantzen Superior Z's in the top section. Have just alligator clipped the swamping resistor in place until I get the final settings. Will hopefully trialling these on a friends LS soon. Inductors are custom hand wound 3mm (8 gauge) for the bass & Solen Litz for the top. The bass inductors weigh about 5kg each so these are quite a handful & I'm hoping that this will give a noticeable improvement to the bottom end of the Belles. I'll be porting the cabs up into the mid horn cabinet & using the foam layer mod in the doghouse. Hope to start cutting wood early next year.

Great stuff.....really appreciate your input.....that sort of info is invaluable. I will experiment with all these options when my cabs are complete. Will be posting a Belle build sometime in the new year & will post pics of my crossover build in the next few days (AP12-500 / AP15-6000 with custom components). Thanks again.

I just occurred to me.......why can't I use digital EQ to achieve the boost & cut needed? I have digital parametric EQ with the Amarra software playback that I use & can easily set that for the boost or cut that is needed. So....6db of boost at 39Hz & is there any cut required to protect the woofer at low frequencies?

Thanks for the info Marvel. I don't run an active set up & have an integrated & cannot seperate the pre & power. Just wondering if there is a schematic somewhere to build a passive that will do the job.

HI all, Does anyone know the full detail for adding the passive EQ filter for the ported LS mod? I'd really like to add this to get the max out of the bass reflex mod. I need the values, or a circuit diagram & what does it connect to? Is it a seperate crossove or added to the existing? Here's a quote from the original explanation. Posted August 25, 2009 Original text from Dennis: The taper rate of a LaScala is 100hz,The mouth area is good for 125hz. Below this it is a big woofer in a small sealed box.If we plug the T/S parameters for the K33E into a box program we will see that the Qtc=.85, the Fc=82.5hz, and the F3=70.9hz. If we close in the back of the high frequency cabinet and open the woofer rear chamber up into this volume and fill with fiberglass we now have Qtc=.577, Fc=58.2hz, F3=73.6hz . Bessel=Qtc.577=D2 gives the best transient response and the least group delay of all the sealed boxes.At 30hz the Qtc=.577 has 4.5dB more output than the Qtc=.85 . Compared with sealed enclosures,the transient performance of the best vented enclosure is worse than the best sealed box enclosure.Since we have made great gains in performance some may elect to stop here.But please read on.The next step is to port it. The K33E is not the optimum woofer for this but it works pretty good. With the box size optimized for a D2 we can port the stock woofer to an SC4.The transient response of an SC4 while not as good as an SBB4(more on this later)is better than the more common QB3. Unequalized the F3=49hz and has 3dB more output at 30hz than the D2. The response curves are parallel with the D2 the only difference being the Fc being a half octave lower with the SC4 and the output being 3dB higher from 30~70hz. The output of the SC4 does not drop lower than the D2 until you go below 17hz. Again this may be a stopping point for some. But by adding a simple two pole high pass filter ahead of the power amp we can now have a C6 with a -3dB point of 31hz. Since this is the Fb of the system there is no increase in cone excursion or distortion. The filter consists of a cap, an inductor and a pot. The pot allows adjustment at Fb of +/- 3dB. This is similar to being able to change the Qtc of a sealed box from .5~1.0 .If you think about it we have the choice between a D2,SC4,and a C6 in the same box by plugging the port and/or bypassing the eq. If you have a SET amp or simply want to get the most out of the LaScala you will want to upgrade the woofer to something with a lower Qts. The Klipsch K43E does the trick, as do the EV DL15W and the JBL 2205. The EV and JBL drivers require some minor network changes. The lower Qts drivers allow for an SBB4 alignment which has the best transient response of the vented alignments. With no eq they have 3dB more output at 30hz than the stock woofer. With eq we have a maximally flat B6 and the F3 of the system is 27~28hz. If using a solid state amp with the low Qts woofers a small resistor must be added in series with the driver to have the same Rg as the SET does. This mod can be backed out of a stock LaScala with no externally visible changes if you don't like it. No one has ever gone back to stock after hearing this mod

This may not be of use, but here's one for the K69 with the 402 horn.

Haven't actually heard a Cornwall, but the general response from everything I've read about Cornscala's is that the bass is significantly deeper than a LS, so will take your comment on board & also trust the Klipsch engineers & stick with the tried & proven port & cabinet dimensions. Anyone care to comment on if I move the bass driver to the top of the cab & the port to just underneath the bass driver, as to whether this will alter the sound? The bass cab will only have the bass driver in it, with the horn in a seperate cab above it. I want to get the bass driver closer to the mid horn & put the port directly under the bass driver.

Quite happy with the response, just curious as to why it's different to a Cornwall.

No one? I just need to verify that the tuning is correct before I start building.

So here's my calcs from Win ISD & I have gone with 2 round ports 90mm diameter - is this the same as the rectangular port of the Cornscala? Should I use this port combination or the standard Cornwall port?

Advice need on port location for a set of Cornscala's I'm putting together. Cabinet dimensions will be the same as the factory Cornwall, but the bass bin will only have the woofer in it, the mids & tops will be in a seperate cabinet on top of the bass bin. I want to mount the bass driver towards the top of the cabinet & have the same size port as the Cornwall just below the bass driver, rather than at the bottom of the bass cabinet. Anyone see any issues with doing this? Secondly, will be using the Crites 1526C woofer & when I run sims in Win ISD, it comes up with a 160 litre cab instead of the 183 litre cab of the Cornwall & the port dimensions are totally different than the Cornwalls. From research, I see that everyone uses the port dimensions of the Cornwall for the Cornscala, so a bit confused as to why this is. I'm sure the Klipsch engineers knew what they were doing when they designed the Cornwall, maybe they were aiming for a particular response or sound?