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I'm not familiar with the Marchand crossover you are using, but when you biamp don't you just connect the low frequency speaker to the low frequency outputs on the electronic crossover & the high frequency speaker to the high frequency outputs on the electronic crossover? I don't understand why you are still connecting the passive crossover into the system. Regards, John

Yes, I did build the kit......it was an extremely labour intensive job, but then also very economical for the result you achieve.........and I'm completely happy with the finished product & the sound quality...........you'd have to spend thousands to get a better sound than these & even then I don't really know if it would actually be any better.........Dave was very helpful as we had a few issues with the fitting of the 399's to his adaptors, but he sorted all that out for me.........If I was to do it again, I wouldn't use the adaptors, but would get him to make the throat down to the 1.4inch size without any adaptors............I figure I'm not changing drivers with these babies!!!

and the 399's........this doesn't really show the scale of these things...........but they sure have an awesome sound.

another view.....before the drivers were fitted.

I'm using Al's universal, but have modified it a little.................. I've changed all the mid & top end caps for Jantzen Superior Z caps & am in the process of splitting it into 2 sections to basically build Al's AP12-500 mated to an AP12-6000......................... For the AP12-500 I have 10 gauge North Creek Audio coils & Sonicaps & for the 6000Hz section I'll stick with the Jantzens & the originla Solen Litz inductors.................... Can't wait to hear those NC inductors.....they're massive!!!!.................I've also changed out the mids for Dave's Elliptracs mated to GPA 399.s............awesome.............in hindsight I should have just gone with these from the very beginning...........those GPA drivers are amazing!!!!!!

another view.

The original Crites CT 125,s I had where fitted to a "baby cheeks" clone. I can't remember what brand or type they were....try a google search for "baby cheeks horn flare"??? those horns opened up the top end considerably. I've since moved on to JBL 2404's.

I've tried lots of different dampening materials in bass cabinets, but I always come back to the old fashioned fibreglass insulation. Seems to impart a warmer smoother sound to the bottom end. You may have to line over the top of the fibreglass with some speaker grill cloth to prevent the fibreglass from flying all over the interior of the cabinet with the air pressure from the bass driver.

Front view.

....or like this....to time align the tweeter with the mid driver.

Thanks for the advice Peter. This will be a long term speaker & I intend to use the Crites cast woofer, as that will integrate with the crossovers that I currently have (AP12-500 + AP 15-6000). I don't want to go down the path of re inventing a crossover to suit another type of woofer. My end goal is to get a warmer, fuller sound from the bass than my current ported La Scala design, so I'm not sure how to achieve this, short of building something & listening to it. I modelled with the 40 Hz tuning as most here say that the Cornscala sounds best with that tuning, however, I can sacrifice some efficiency for lower response. I notice when I do that, that the response falls off in the mid bass though. My original plan was to build an Onken cabinet with the Altec 416 series woofer, but I've heard so many stories of trying to get the crossover right,that it just seemed like opening another can of worms. The mids & tops are GPA 399's mounted to Elliptrac's & JBL 2504's.

Fourth & final screen shot

Third screen shot

Second screen shot

I've decided to put together a set of Cornscala's & want to have the dimensions appropriate to my current Elliptrac mid horn set up , so they will vary a little in the dimensions of the usual styles...........................................To that end, I've downloaded Win ISD to design the dimensions & calculate the port dimensions & my question relates to the dimensions of the port, or ports, as the case may be................................................................I have 4 spare Precision Ports (4" diam) so am keen to use these, as opposed to the standard slot type port in the bottom of the cabinet. I have no experience using Win ISD so I'm just wanting to check things before I start cutting wood. I've attached some screen shots of the results. The programs recommendation when using 2 x 4" ports per cabinet is that they be 3.46 " in length. If I change the design to using just a single port, it says that the port should be only 0.26 inches in length.....................................................................So my question is, are these calculations correct? Maybe I'm not using the program correctly? It just seems strange that with 2 ports the length of the port is 3.46 inches & with 1 port the length computes as 0.26 inches.............................................. Any help appreciated..............................Thanks,...............................John......I posted this under updates & mods, but got no replies.......hoping someone here can advise.

Purdy!.......I'm sure it will be a step forward.

Fourth & final screenshot.

Third screenshot.

Next screenshot.

I've decided to put together a set of Cornscala's & want to have the dimensions appropriate to my current Elliptrac mid horn set up , so they will vary a little in the dimensions of the usual styles...........................................To that end, I've downloaded Win ISD to design the dimensions & calculate the port dimensions & my question relates to the dimensions of the port, or ports, as the case may be................................................................I have 4 spare Precision Ports (4" diam) so am keen to use these, as opposed to the standard slot type port in the bottom of the cabinet. I have no experience using Win ISD so I'm just wanting to check things before I start cutting wood. I've attached some screen shots of the results. The programs recommendation when using 2 x 4" ports per cabinet is that they be 3.12 " in length (79.2mm). If I change the design to using just a single port, it says that the port should be only 3mm in length.....................................................................So my question is, are these calculations correct? Maybe I'm not using the program correctly? It just seems strange that with 2 ports the length of the port is 79.2mm & with 1 port the length computes as 3mm...................................I've adjusted the total volume as 6.7ft3 to allow for bracing & such..................... Any help appreciated..............................Thanks,...............................John

The balance between the drivers is one of the most important things. It alters the whole characteristics of the sound. You do need a bit of flexibility on the autoformer. I usually back the mids off a tad too much & then bring them back until the sound just starts to crispen up. Pick out an album that you know that the recording is not too dull & not too bright & use that as your reference........I've just switched from the standard K55's to some GPA 399's & after a lot of experimenting I ended up at -10.4db for the mids & -5db for my JBL 2404 tweeter............so that's X & 3 on the autoformer......attenuation for the tweeter is via Al's transformer attenuator...............the CT 125 isn't as hot as the JBL, so that may be OK........oh & previously with the K55's I was at X & 4, which is -6.2 db.

One final one. Not sure why you can see the white type marks around some of the perimeter, but they aren't visible in reality. Must be the camera or the light.......sorry about the fingermarks.

These pics are before I fitted the drivers, so that's masking tape you can see down the throat.

With a bit of trimming they fitted beautifully into the existing cabinets.

oh....& by the way......no affiliation with GPA