Looking to upgrade to horns
- Thread starter roccus
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Take a look if you have not already. You can buy one piece at a time like Johnny Cash:
https://critesspeakers.com/cornscala.html
https://critesspeakers.com/cornscala.html
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- Halfbiass...Electron Herder and Backass Woof
- Joined
- Jan 14, 2011
- Messages
- 74,877
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
Lee . yep the 808-8b's but I have changed the diaphragm to the 802. GPA still builds all original Altec parts.
so the 808-8b now is a 802-8g with the phragm swap.
As you know, ya got to be easy on the power to compression drivers. One reason I like active crossovers . I can drive them with there
own amp to control output power, slope and amp choice. They don't need much . When I ran passive's I would kill them once in a while if I got
heavy on the go knob. $150.oo a pop for new phrgm's.
I still have the Dahlquist bi amp system also.
so the 808-8b now is a 802-8g with the phragm swap.
As you know, ya got to be easy on the power to compression drivers. One reason I like active crossovers . I can drive them with there
own amp to control output power, slope and amp choice. They don't need much . When I ran passive's I would kill them once in a while if I got
heavy on the go knob. $150.oo a pop for new phrgm's.
I still have the Dahlquist bi amp system also.
- Joined
- Jan 14, 2011
- Messages
- 74,877
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
For someone who is patient (and has mid-level wood working skills at least) and wants to slowly build a horn system, I would recommend a two-piece ported La Scala system. The La Scala is much easier to construct than a K-Horn with minimal angles to figure out. Construct the bass cabinet as a separate piece from the top section, so you can experiment with different mid-range drivers/horns and tweeters.
Porting a La Scala is the only way to go in my opinion. Stock, the La Scala is a giant 100Hz and up "satellite speaker". The reason I suggest the La Scala is because not everyone has the room to set-up the K-Horns properly and the K-Horn is also fairly large. The La Scala is large but more manageable than a K-Horn and placement is more flexible. The ported La Scala prefers a corner to load the port (mine are ported to the rear, which I think work and sound the best), but it is not absolutely necessary.
The original design lends itself well to the porting mod. To extract the most from the porting mod, you need a special 12dB/octave high pass filter with a high "Q". This filter is centered at 35Hz and gives 6dB of boost, then rolls of simulating an infra-sonic filter. This roll off is necessary to keep the woofer under control below the porting frequency.
Some may question how good a ported La Scala can sound, but until you have heard how much the bass comes up after the mod, it's a night and day difference. The bass is tight, dynamic and fast (The way a lot of people like it here... wink wink). It's been decades since I have heard K-Horns, but the ported La Scala is the closest you will come (bass wise) in a smaller package.
For those who want to experiment, I have designed the high pass filter you will need to make this project successful. See attached circuit and graph for reference. A simple power supply is shown too.
You don't have to get crazy choosing an op-amp, but I do prefer bi-polar input types for my projects. One of my favorites is the NJM2068. It is low noise and has good specs for $0.50.
Forgot to mention - The bass EQ circuit can go into your tape or EQ loop on your preamp.
Porting a La Scala is the only way to go in my opinion. Stock, the La Scala is a giant 100Hz and up "satellite speaker". The reason I suggest the La Scala is because not everyone has the room to set-up the K-Horns properly and the K-Horn is also fairly large. The La Scala is large but more manageable than a K-Horn and placement is more flexible. The ported La Scala prefers a corner to load the port (mine are ported to the rear, which I think work and sound the best), but it is not absolutely necessary.
The original design lends itself well to the porting mod. To extract the most from the porting mod, you need a special 12dB/octave high pass filter with a high "Q". This filter is centered at 35Hz and gives 6dB of boost, then rolls of simulating an infra-sonic filter. This roll off is necessary to keep the woofer under control below the porting frequency.
Some may question how good a ported La Scala can sound, but until you have heard how much the bass comes up after the mod, it's a night and day difference. The bass is tight, dynamic and fast (The way a lot of people like it here... wink wink). It's been decades since I have heard K-Horns, but the ported La Scala is the closest you will come (bass wise) in a smaller package.
For those who want to experiment, I have designed the high pass filter you will need to make this project successful. See attached circuit and graph for reference. A simple power supply is shown too.
You don't have to get crazy choosing an op-amp, but I do prefer bi-polar input types for my projects. One of my favorites is the NJM2068. It is low noise and has good specs for $0.50.
Forgot to mention - The bass EQ circuit can go into your tape or EQ loop on your preamp.
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- Joined
- Jan 14, 2011
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- 74,877
- Location
- Gillette, Wyo.
- Tagline
- Halfbiass...Electron Herder and Backass Woof
Hide 'em in the basement. She'll never notice!
