Hi
If you give the Sound Org in York a ring I traded my isobariks and Aktiv crossover in just before Christmas, they may still have it
Active Isobariks the best ive experienced
- Thread starter dspatterson
- Start date
If you give the Sound Org in York a ring I traded my isobariks and Aktiv crossover in just before Christmas, they may still have it
nostromo
pfm Member
dspatterson, I'm really intrigued by your Rotel 991 as you mention these can outperform Klouts on the bass. I'm on a tight budget leash too and always look longingly at getting hold of 6 Klouts and then recapping them etc. But the Rotel 991 maybe a better route.
How much is a 991 s/h these days...I might experiment. One review I just glimpsed stated under 1K USD new...so could be very affordable. I know those nc200 Avondales are very Naim like, I have heard those...I just prefer a properly designed case and some aesthetic too.
How much is a 991 s/h these days...I might experiment. One review I just glimpsed stated under 1K USD new...so could be very affordable. I know those nc200 Avondales are very Naim like, I have heard those...I just prefer a properly designed case and some aesthetic too.
Rotel amps are good. Years ago I used a Rotel integrated driving my Briks while my 250 was away getting serviced. At low volume, in all honesty I couldn't really hear much difference! They are good sounding and reliable amps.
I don't think active is some kind of magic bullet for Briks. Yes, active can sound better but that's true with any speaker. I've heard active Briks sound ordinary and passive ones astonishing. Bottom line is that they are tricky to get working properly but have epic potential when you do. However you do it. I've heard loads of speakers over the years, some have been great in certain areas, but nothing has made me think about changing the Briks.
nostromo
pfm Member
Have to disagree with you there. Active operation provides far more reserve power and you get far better dynamics and grip of the drivers giving tight accurate reproduction of rock music, with minimal chance of clipping or distortion.
nostromo
pfm Member
RyanSoundLab
Trade: Ryan Sound Lab
When I reverse-engineered the original brik's passive crossover, it showed bass down -3db@292Hz (2-pole), mid down -3db@423Hz and 2.4kHz (both 3-pole), and the tweeter [email protected](3-pole). I can't verify the actual design points but those numbers are what the Spice model shows if I plug in the nominal values for the caps, etc in the actual Linn passive crossover. Others have published similar but somewhat different numbers and that's OK, too.
Regarding the lack of specialized, speaker-specific characteristics in the active version, this is due to the fact that you are now driving the cones directly with an extremely low impedance amp output instead of through a "matching" passive network. Special speaker tweaks aren't needed because those speaker resonances (causing wild variations in impedance and subsequent mismatch with the passive crossover) are effectively controlled by direct connection to the power amp. With a typical output impedance of way less than 1 ohm, the output amp just doesn't let the speaker resonate.
I might add one other thought to this discussion - when you go active, the speakers are directly connected to the power amps. With the occasional amp turn-on thump, a large pulse can get to your tweeters in particular - not a good thing. I blew all 4 of mine out from this. So.....I suggest putting a top quality polypropylene cap in the line to the tweeters, say 4uf/50v, to save them from possible extinction.
S-Man
StrivingON
Each drive unit (in a box/baffle) still has its own frequency response and polar radiation characteristics. Standard LR4 slopes cannot fix this no matter how low the output impedance of the power amp.
RyanSoundLab
Trade: Ryan Sound Lab
Forgot one other thing. At least for the passive version, Linn designed it have the mid-range speakers hooked up with inverted polarity. However, when my friend and I did some tests with the active version, we much preferred the polarity to be normal - the same as the woofers and tweeters. Gave a much better central image. Just something else to experiment with.
RyanSoundLab
Trade: Ryan Sound Lab
Agree on the radiation characteristics and frequency response. I was referring to the Zobel networks that target the speaker resonances in my note.
dspatterson
pfm Member
I use an Avondale based amplifier on treble that has a soft start board so no nasty crack.
Re the Rotel 991 they can be had for £300 to £350.. I almost parted with them when i brought the Klouts out of hibernation, i did advertise here not so long ago. I struggled with the kudos of the klout vs the high street mainstream tin can build of the Rotel, but i had to get over it and trust my ears, it was difficult to let go of the Klouts.
BUT the Klouts may have performed better over a full bandwidth where as i was comparing driving bass against bass.
Re the Rotel 991 they can be had for £300 to £350.. I almost parted with them when i brought the Klouts out of hibernation, i did advertise here not so long ago. I struggled with the kudos of the klout vs the high street mainstream tin can build of the Rotel, but i had to get over it and trust my ears, it was difficult to let go of the Klouts.
BUT the Klouts may have performed better over a full bandwidth where as i was comparing driving bass against bass.
nostromo
pfm Member
@RyanSoundLab , great info in your above posts about the crossovers...thanks.
All my drivers are connected normal phase. It's Vangelis ( particularily the track Pulstar that's kills my tweeters)....I'm very wary of volume with that these days.
All my drivers are connected normal phase. It's Vangelis ( particularily the track Pulstar that's kills my tweeters)....I'm very wary of volume with that these days.
Tonewheelkev
...I can dream!!
....I think that I may have ended up with your Aktiv Box!
chris geary
pfm Member
I now have a Linn Crossover that has the upgraded power supply and the Bingo mod. It is better than the NAXO 3-6. The Naim boxes are gone.
I use aktiv Briks with Keltik bass drivers, in quite a large room (31ft x 18ft). I'm using 6 x akurate 2200's to drive them.
The issue I had with the B139's was having to be careful with certain bass heavy material, as the 139's would often hit the end stops and make rather alarming noises, even at moderate volume levels, (with the Bingo fitted). I have never experienced this problem with the Keltik drivers.
The issue I had with the B139's was having to be careful with certain bass heavy material, as the 139's would often hit the end stops and make rather alarming noises, even at moderate volume levels, (with the Bingo fitted). I have never experienced this problem with the Keltik drivers.