BK Gemini Mk2

[ChaosFlower]

If anyone else could chime in, answer any of my unanswered questions.. I would be very grateful.. subs are a complete unknown to me.

And I thought of another question.. I am mostly a 2 channel music guy.. but I do love my plasma screens.. never went the LCD route.. but I do movies in 2 channel... presumably the sub will still add to my movie experience?

 

[MaryWhitehouse]

My Missions have two 6.3in drivers and an inch soft dome tweeter. I expect I will put a heatsink on the Gemini plate using double sided heatsink tape. I have 12in 5v USB fans sucking air out of the vents on my elderly Arcam and other amps. A tad autistic? Maybe. I like looking after stuff. The cooler electronics are the happier they are.

You don't need to add any cooling, it'll be fine. A Gemini will reinforce the bass nicely but will add little 'thump' if you want a really unsubtle film experience. To generate the pressures needed for that you'd need to move up a lot. That said for normal use it will make a huge difference.

 

[Jamesw71]

Skip the Gemini. Try something like a monolith

 

[stuproberts]

Thank you.. our main speakers not that disimilar so I could ask.. did you find a bit more oomph from the Gemini? The sub works well with your floorstanders and adds a bit more thump? I really don't know what to expect. My system is well loved... I just thought.. bk.. british made.. well regarded.. maybe a bit more thump would be nice.

I don’t think it’s an oomph thing although you could do that with it. I find it’s more of an underpinning of the bass (just seems to make it feel firmer and faster)

 

[ChaosFlower]

Skip the Gemini. Try something like a monolith

In my room lol dude.. my room is 3.5m by 3m... tiny just measured it..

I just want a bit more low end thump in music...
Plus I can't afford the monolith
Plus I have already pulled trigger on gemini 2 grade B Black ash gemini!
Should come later this week

 

[ChaosFlower]

I don’t think it’s an oomph thing although you could do that with it. I find it’s more of an underpinning of the bass (just seems to make it feel firmer and faster)

Yes. That's it. I just want more precise and more present lows. Just a bit more than the Arcam Alpha 10 and Mission M74's can give... enough that I don't have to crank the now elderly gent Alpha 10 too high to get it...

 

[ChaosFlower]

You don't need to add any cooling, it'll be fine. A Gemini will reinforce the bass nicely but will add little 'thump' if you want a really unsubtle film experience. To generate the pressures needed for that you'd need to move up a lot. That said for normal use it will make a huge difference.

Yes reinforcement is what I am after in music. Any added benefit to movies would also be nice bearingt in mind that that is not my main priority. I am not a home cinema guy. Music mainly.. but a 2 channel with sub decent movie experience also a bonus...

I find the mission M74's are great with 4/4 dance.. but they lose their way a little bit with rock.. when it gets very busy the bass diminishes... I thought the sub might stop that happening.

 

[B4ker13]

Sorry for bringing up the hum conversation, but I'm still looking for a fix.
Basically I've read loads about this issue and just changed the main capacitors, but alas the hum remains. I've checked everything, unplugged everything and now changed the capacitors. Am I correct in thinking a DC filter mains cable is my last port of call?

Changing the caps has improved performance slightly and reduced the hum slightly, but not removed it.

 

[Conrad.]

If it's transformer hum the ATL hifi DC blockers worked well for me.

Combined module DC Blocker (trap, filter) & EMI/RFI/Common Mode Filter – Assembled in Case – ATL Audio Ltd.

www.atlhifi.com

Did we already discuss this on another thread?

 

[B4ker13]

Did we already discuss this on another thread?
[/QUOTE]

Maybe, not sure. I attempted to sort the hum out a while ago, but gave up as it wasn't too intrusive. Now I'm having another go due to lockdown boredom. I rang bk and they sent me some caps as they said my sub was 10 years old. When I opened it up, I thought that might not be the problem as original caps looked fine.

 

[Conrad.]

I bought one of the above as I have power amps that have large transformers in them that hummed. This killed it completely. Eventually I bought the double socket higher powered one as I now have two amps.

I have the single socket one spare and if you want to borrow it you'd be more than welcome to test it out if you're happy to cover return postage.

 

[B4ker13]

I bought one of the above as I have power amps that have large transformers in them that hummed. This killed it completely. Eventually I bought the double socket higher powered one as I now have two amps.

I have the single socket one spare and if you want to borrow it you'd be more than welcome to test it out if you're happy to cover return postage.

That is very kind of you to offer, but as the problem is not too bad I think I'll just live with it after seeing the price to fix it is almost as much as I paid for the sub.

Again thanks for the offer.

 

[Conrad.]

Fair, probably diminishing returns!

 

[ChaosFlower]

Sorry for bringing up the hum conversation, but I'm still looking for a fix.
Basically I've read loads about this issue and just changed the main capacitors, but alas the hum remains. I've checked everything, unplugged everything and now changed the capacitors. Am I correct in thinking a DC filter mains cable is my last port of call?

Changing the caps has improved performance slightly and reduced the hum slightly, but not removed it.

View attachment 1405683

They use Samwha don't they? South Korean. Good caps. I have two twenty year old Arcam Alpha amps stuffed with Rubycons and Samwha etc that still show good on an ESR meter. Electrolytic Caps are microphonic but I can't see need for changing them unless they are older than +10 years or are exhibiting issues. A lot of amp manufacturers do damp the big main filter caps with glues and foams. Arcam used to wedge a piece of foam between main filter caps and lid. Maybe they still do. My technics 900mk2 has a big foam ring around the main filter caps. Blu tack is good for damping around the base of caps. Mass damping helps the performance of electrolytics. But hums aren't usually caps I don't think.. aren't they almost always transformer related? Maybe the sub doesn't have good filtering? Would one of those Tacima filter blocks help?

 

[B4ker13]

Yes they do use samwha caps. Even though my sub is 10+ years old, they looked fine. No damping around the base, just double sided sticky tape, to help them stay put. I changed them for the simple reason of trying to eliminate the cheapest problems first. My hum is actually coming from the driver.

 

[ChaosFlower]

I've just set up my BK G2..

Appears to have no hum.

I have no idea how to best set it up. Using high level connections. Sometimes I think 0 degrees.. sometimes 90, 180.. maybe I have a tin ear.. maybe I need to choose a simple track to really try get the exact phase?

Amp is Arcam Alpha 10. Mission M74 floorstander speakers. 2 channel and a sub. This is primarily for music.

Is there like a good youtube video test tone thing that could help me? Any tips?

I just wanted a bit more bass to allow lower volume of Arcam 10... gain set at 9pm or less seems fine.. crossover maybe 50, 60...Hz

 

[ChaosFlower]

Ok.. I think 9pm on gain.. 55Hz on crossover.. and 0 degrees on phase.. does that sound about right with my set up?

 

[ChaosFlower]

Have to say I love this Gemini. I never wanted outright boom so I turned the gain way down to about 9pm. Just enough to fill in that very low end below 55hz.. I no longer feel the need to crank up the Arcam Alpha 10 to get the bass up.. now I am listening to a lower volume yet I have that missing low end.. I should have bought one of these years ago! I really missed out!

For anyone else thinking of buying - do! I got a grade B cabinet from BK on ebay (collusussubs). There are some superficial marks on the veneer underneath that you cannot see. The cabinet and driver is otherwise immaculate. Bargain. Finally after years I have the sound I want.