joessportster Posted May 2, 2018 Share Posted May 2, 2018 So I have my SS set by N. Pass and it sounds great but as expected there is no real bass SLAM so I am considering Bi-Amping the cornscala, My question is this, Cant I simply disconnect the woofer from the Crossover, use the existing crossover for the top half with my set amp, and get an active crossover and a more powerful amp with Volume control for the bass section set the X-over at the same freq. as the original passive, and simply adjust the volume on the bass amp for integration of sound. thoughts ? 1 Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 2, 2018 Share Posted May 2, 2018 Your crossover needs to be bi-wire-able. You would need to get the low frequency section out of the power path because no telling what impedance the amplifier will see if you remove the woofer load (12db+ crossovers). 6db with only a coil the circuit will be open on typical crossovers. This also depends on the the type of crossover along with the possibility of changing the frequency response some along with impacts on the actual crossover point and slope of the electronic crossover. It would be much safer if your woofer and upper range were able to be isolated so you could remove the woofer section from the circuit. Quote Link to comment Share on other sites More sharing options...
wvu80 Posted May 2, 2018 Share Posted May 2, 2018 1 hour ago, pzannucci said: You would need to get the low frequency section out of the power path because no telling what impedance the amplifier will see if you remove the woofer load (12db+ crossovers). I am no expert on such things but I was wondering the same thing. The crossover was designed to produce an 8 Ohm load and if you take the woofer out (which consumes most of the power) the impedance would not be right. In the four years I have been posting here I've never read about anybody running a passive HF section and an active LF. I have to tell you it sounds like an interesting idea. I hope you follow through with some more technical discussion to find out why this idea is, or is not feasible to produce the bass slam you want. Maybe this will be your next million dollar idea! Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 2, 2018 Share Posted May 2, 2018 It is most feasible if you can get the low frequency crossover out of the picture. The key thing would be the phase / time domain and roll off since the passive high frequency and low frequency sections were designed to compensate for each other. Edit: many electronic crossovers are 24db per octave. Most default configurations are 12db on the passive. Quote Link to comment Share on other sites More sharing options...
mboxler Posted May 2, 2018 Share Posted May 2, 2018 It shouldn't be that hard to bypass the hi-pass portion of the passive crossover and drive the mid/high drivers using the hi-pass of the active crossover. If you could post a picture/schematic of the passive crossover, we could find out. Mike Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 2, 2018 Author Share Posted May 2, 2018 My crossover is the ALK cornscalawall pic below, This is Al's picture but mine is identical. I would have thought I could simply remove the woofer lead. Guess not though.. Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 2, 2018 Author Share Posted May 2, 2018 Anyone have a lead on a decent active crossover that wont break the bank ? Any opinions on this https://www.xkitz.com/products/linkwitz-riley-3-way-active-crossover-fully-assembled-xover-3 Quote Link to comment Share on other sites More sharing options...
mboxler Posted May 2, 2018 Share Posted May 2, 2018 I've been curious about the Xkitz products too. If you are willing to do some DIY, I'd be happy to send you a pair of Marchand XM1's with 500 hz modules, as well as the power supply for them. They are unbalanced input/output only. Regarding Al's crossover, hopefully someone smarter than me will chime in. It appears that the ends of the 33uf cap are soldered to copper (?) posts. If one were to connect a 14 AWG wire with alligator clips to the two posts, would that not bypass the capacitor completely? Now the crossover will only passively split the high pass signal from the active crossover to the mid and high drivers. Mike Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 2, 2018 Author Share Posted May 2, 2018 Really appreciate the offer, sounds like it would be fun to try, I had a couple marchand X-overs years ago and always found they were quality products. Are these something you would consider selling ? Quote Link to comment Share on other sites More sharing options...
mboxler Posted May 2, 2018 Share Posted May 2, 2018 PM sent. Quote Link to comment Share on other sites More sharing options...
The Dude Posted May 2, 2018 Share Posted May 2, 2018 I believe you could go with the AP15-6000t or ES5800 from AL that will handle that Squawker to tweeter and you could get by with a MINIDSP or the device you mentioned. https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4 I've got a minidsp sitting if you want to try it. Pm me for details. Quote Link to comment Share on other sites More sharing options...
pzannucci Posted May 3, 2018 Share Posted May 3, 2018 If the mid/treble section isn't behind the woofer choke, you can probably just unhook one leg of the choke from the input terminal. That will get the woofer completely out of the circuit. If Al tied the mid/treble behind the choke for some reason, you can't do that. I doubt it is though. Quote Link to comment Share on other sites More sharing options...
Marvel Posted May 4, 2018 Share Posted May 4, 2018 On 5/2/2018 at 9:28 AM, wvu80 said: In the four years I have been posting here I've never read about anybody running a passive HF section and an active LF. I have to tell you it sounds like an interesting idea. I hope you follow through with some more technical discussion to find out why this idea is, or is not feasible to produce the bass slam you want. Since I physically time aligned the mids and tweets on my LS, it is something I am working on as well. I would use the 75wpc amp to drive the LS bottoms, and 2a3 amps (3.5 wpc) to drive the mid/tweets through the passive. I am sure there are others on here who have done this. As Peter has said, the woofe portion of the crossover has to be out of the circuit. IOW, you just need a two way crossover for the mid/tweeters. Bruce Quote Link to comment Share on other sites More sharing options...
wvu80 Posted May 5, 2018 Share Posted May 5, 2018 12 hours ago, Marvel said: Since I physically time aligned the mids and tweets on my LS, it is something I am working on as well. I would use the 75wpc amp to drive the LS bottoms, and 2a3 amps (3.5 wpc) to drive the mid/tweets through the passive. I am sure there are others on here who have done this. As Peter has said, the woof portion of the crossover has to be out of the circuit. IOW, you just need a two way crossover for the mid/tweeters. Your comment (bolded by me) exposes my ignorance of exactly how crossovers work. If a 3-way has an 8 Ohm resistance, if you take the power hungry woofs out of the circuit, what would the mid and tweeter need to show? Surely not an 8 Ohm load, but not 4 Ohm either. Feel free to pose/answer a better question if mine is not the right one. Quote Link to comment Share on other sites More sharing options...
Marvel Posted May 5, 2018 Share Posted May 5, 2018 Sure, a passive for a two way Jubilee is a nominal 8 ohms. You just have one that crosses over at 4.5k or 6k. The electronic crossover would then protect the mid by sending only 400Hz and up, or whatever the Cornscala woofer to mid gets. Exactly what The Dude states above. A simple crossover is designed for the two impedances of a two way and an overall impedance. Bruce 1 Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 6, 2018 Author Share Posted May 6, 2018 Marvel, You are saying (I think) if I take the woofer disconnect it & bypass the cap, I would then essentially have a 2 way Passive sending only 500hz up to the mid and that crosses over again at 5800 for the tweet. and a load close to 8 ohm ? I am going to try this no matter I just have to get the crossover when $$$ allows, I have a pair of Pass ACA set amps for mid highs, and a passive pre with 2 outputs so only needing a bass amp with a volume control, and the active crossover for the bass set at 500 HZ. Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 6, 2018 Author Share Posted May 6, 2018 What about something like this for the bass crossover https://www.ebay.com/itm/Rolls-SX45-2-Way-Stereo-Crossover-with-Mono-Sub-Output/352333996419?epid=1100302412&hash=item5208be2183:g:mW0AAOSw5Oxa2NZw Quote Link to comment Share on other sites More sharing options...
Khornukopia Posted May 6, 2018 Share Posted May 6, 2018 13 hours ago, joessportster said: What about something like this for the bass crossover https://www.ebay.com/itm/Rolls-SX45-2-Way-Stereo-Crossover-with-Mono-Sub-Output/352333996419?epid=1100302412&hash=item5208be2183:g:mW0AAOSw5Oxa2NZw I tried one of those with some La Scalas a few years ago and could hear some background hiss at low volume music listening. On 5/2/2018 at 4:16 AM, joessportster said: So I have my SS set by N. Pass and it sounds great but as expected there is no real bass SLAM so I am considering Bi-Amping the cornscala, My question is this, Cant I simply disconnect the woofer from the Crossover, use the existing crossover for the top half with my set amp, and get an active crossover and a more powerful amp with Volume control for the bass section set the X-over at the same freq. as the original passive, and simply adjust the volume on the bass amp for integration of sound. thoughts ? Maybe your room acoustics are affecting the bass response. Does the bass sound better in a back corner of the room, or on the other side of a doorway into another room. If so, you may have standing waves causing a null at the listening position. Eliminate that possibility before spending money on more equipment. Quote Link to comment Share on other sites More sharing options...
mboxler Posted May 6, 2018 Share Posted May 6, 2018 Not sure if this helps, but here's a Type-A-BA (bi-amp) crossover I'm working on. SInce the active crossover replaces the 2.5 mh inductor (low pass filter) and the 13 uf capacitor (high pass filter) of the Type-A crossover, all that remains is an autoformer and 2 uf cap. I even went so far as to reverse the function of the autoformer. Instead of attenuating the mid by 3 db, the autoformer passes a 3 db gain to the tweeter. Since I'm using the same amp type for the low and high pass, I run the low pass amp at full volume, and the high pass amp at around 12 o'clock. Mike Quote Link to comment Share on other sites More sharing options...
Schu Posted May 6, 2018 Share Posted May 6, 2018 On 5/2/2018 at 4:16 AM, joessportster said: So I have my SS set by N. Pass and it sounds great but as expected there is no real bass SLAM so I am considering Bi-Amping the cornscala, My question is this, Cant I simply disconnect the woofer from the Crossover, use the existing crossover for the top half with my set amp, and get an active crossover and a more powerful amp with Volume control for the bass section set the X-over at the same freq. as the original passive, and simply adjust the volume on the bass amp for integration of sound. thoughts ? since you're already a fan... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.