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Isobarik Lovers

oldie

oldie

pfm Member
Hi All,
I am thinking of changing my active SBL's for passive Brik's ,as being a poor old age pensioner I can't afford another 250 and snaxo to go active. So the question that I just can't get my head round is how do you wire up Bricks with two 250's I know it can be done as I have seen it, but a series of senior moments are making my befuddled brain go into spasms, Any help or instructions on how this is achieved would be greatly appreciated
oldie
 
Use one 250 per channel and just use one channel on each 250. Its similar to using two 135s.

Cheers,

DV
 
Hi,

I did it in a simple way before I went active.

From the HiCap or Snaps get Flashback sales to make you a lead that has two plugs instead of the one plug to a single 250. Basically instead of one lead carrying both channels you get them split into two leads from the HiCap with two plugs.

Then plug one into each 250 and you are basically only using one channel on each 250 so the power supply in the 250 is only driving one channel rather than two.

Yes you can get more electronics to use both channels in both 250's to drive the Isobariks in semi active mode but for a very small outlay you can get a pretty big increase by just using a single channel in each 250.

I will have a look tonight when I go home and see if I still have the lead.

Cheers

John
 
depends on the age of the briks

I had external crossovers and had my 135s on the treble units and one 250 taking care of everything else

sounded best that way

Dave
 
Personally i think Briks only come into their own driven actively - i had them passive and they sounded slow(previously Kans)

Your SBL will sound fast and dynamic compared to passive briks(but less bass extension)

I recently demo Neat Momentum 4i - stunning speaker - if you like what the briks do (especially bass extension) - these will not dissapoint

Brian
 
If I understand you correctly then you need a specific variant of the Isobarkis to do this: The DMS ones with the two parallel wired crossovers in the base of the speaker behind a removable panel. All you do is disconnect the red/black input wires from one of the crossovers and reconnect these wires to one of the available pairs of sockets (3 free pairs IIRC?). You then power L/R with one 250 and L/R with the other 250.

Easiest way to understand this is to consider that each Isobarik is essintially a pair of KefKit 3s in one cabinet (they were exactly this from 74-77). So just imagine you have 4 individual speakers and 2 L/R stereo power amps.

James.
 
Not true.

The Briks with the large external crossover in the stand are easy to biamp or tri-amp. There are simply links on the circuit board the link the bass input to the mid input and then more that link the mid input to the treble input. Cut one set of these (for bi-amping I would suggest cutting the bass to mid links and have one amp feeding the bass input and the other the mid or treble (doesn't matter which as the remaing link joins the two anyway).

CJ
 
CJ, You are of course correct.

I made the assumption as the OP stated passive Briks that it was a pair of DMS briks that was being referred to, rather that the later active speakers (no DMS/PMS nomenclature) with external passive crossovers. These can be biamped or triamped in the normal fashion. The DMS can only be used with more than one amp as above.

James.
 
If the underside of your Isobariks looks like,

undersidepassive.jpg


IOW they have 4 pairs of connectors, then as standard the two crossovers are wired in parallel. You can use a pair of stereo power amps to some advantage by separating the inputs to each crossover and driving them individually.

With earlier speakers you cannot easily get to the two crossovers, they are inside the Isobarik cavity,

stumo3.jpg


Although you may be able to access the wiring behind the input XLR.

The later '4 Ohm' crossovers do not allow this sort of arrangement, but you can easily implement a more conventional biamp by spliiting the bass from the mid/treble and driving the different parts of the crossover from different amps.

The big win of two power amps with the earlier speakers is that each amp is now seeing an 8 Ohm load and will work better as a consequence.

Paul
 
Hi all,
Please accept my apologies, I should have replied and thanked you all for your advice before,but I just had a senior moment and it slipped my mind
Just to bring everything up to date,Dispite what I stated at first in this thread, I managed to buy a pair of Active Briks in absolute Pristine condition from Lintone Audio they came complete with the Linn Aktiv crossover and Dirkt Power suppy for a very reasonable price (and before someone shouts get a Snaxo it sounds better the answer is no I've already over spent my budget) in fact it was a brilliant bargain so I would like to thank Peter and Tony at Lintone Audio for their help. Then as a cheap skate option I bought a Nap 180 to drive the tweeters instead of the much more expensive Nap 250's. So I have my original two 250's driving the bass and Mid and the 180 driving the tweeters. As my listening room has a wooden suspended floor, ,as I did with my SBL's I have screwed three cross head screws into the floor with two screws at the front, in a triangular pattern just smaller than the briks footprint, into the cross heads sit 4mm ball bearings and a 30mm thick granite slab sits on top of the ball bearings.The Briks and the stands sit on top of the granite slabs, all points adjusted and tightened correctly.
All are positioned as Mr Ellwood suggested as regarding distance between the speakers and the wall behind them. The resulting sound is nice and tight with the extra bass that the SBL's didn't have,but I don't think that I have lost the other attributes that the SBL's are well known for. We had a session last night with Groucho, Simonms and Rasher so a very deep pool of knowledge sitting in judgment, so I'm now awaiting their unbiased opinions, has the itch that I scratched been worth it or was it a upgrade too far
oldie
 
The granite/screws and bearings have gone some way to giving these Briks a slightly different "voice", I used to have briks also but never had anything underneath them and they were also on a suspended floor as Oldie's are.

I would be interested in what others have tried under their briks, if anything at all, Groucho also mentioned that when he bought his the owner had had some new stands built and basically described the originals as shite, was there a Mana stand for them? If so was that any good?

Cheers Si.
 
My view is that any negatives to the result of these Brix over the previous SBLs is in the loss of midrange sweetness, which at times can get edgy with less than good recordings. However, I think this is just a revelation that the LP12 needs yet another service. It isn't the fault of the Brix.
I think it sounds fab and not as warm and wooly as I had expected.
 
isobariks should sound just like big kans.

not much apparent bass just very extended and fast.

mine are sat on the solid steel stands with panel inserts and stuffed with heavy curtains on a solid concrete floor.
 
I made the same move from active SBls to passive Briks about 3 years ago. I had not heard Briks for many years but purchased a pair for a second system that I was putting together at the time. I was rather surprised at the improvement over the SBLs, so much so that I purchased a second pair of Briks for the main system. Before selling the SBLs, I put them back into the system to try them one more time. The Briks won hands down and the SBLs were sold. I am rather puzzled by those who refer to the Briks as slow, lacking in dynamics or coloured. I certainly do not find them so at all. They, IMO, play music very, very well.

To the OP - good luck with your new Briks. Hope they work out for you as well as they did for me.
 
PaulB

Would you ever consider moving to active with the briks, as you did with the SBLs? Seems 'so near but yet so far' if you needed just the one more amp (plus a different x-over, I grant you).

I ran passive briks happily for years but so do not regret the extra cost of going active. Would like less boxes though I must say.
 
mrclick said:
PaulB

Would you ever consider moving to active with the briks, as you did with the SBLs? Seems 'so near but yet so far' if you needed just the one more amp (plus a different x-over, I grant you).

I ran passive briks happily for years but so do not regret the extra cost of going active. Would like less boxes though I must say.
Click to expand...

I have actually never heard active Briks, and unfortunately, both of my pairs of Briks have the internal crossover (and I am not about to modify them myself as it would require major surgery). If a another pair appear locally that have the external crossover, I would be VERY tempted though.
 
PaulB

If I may be so bold as to try to encourage you - I had never heard active briks, or anyone elses briks, or any active speaker come to think of it. And I have virtually no understanding of electronics. I can change a plug on a kettle. My hi-fi journey had always been a solitary one, as it probably is for many (hence the wonder of forums such as this).

My briks are 1988 build and have the internal crossovers in the base of the speaker, but they do have the banana plug sockets available at the back which is essential I suppose.

One day I stumbled on a wiring diagram specifically for converting to active mode for this internal crossover. It is still available on www.mybriks.com in the FAQ section. So I decided to get a Naim snaxo, a couple more 250s, and try it. All you need is a soldering iron, and it is a really easy operation. Honest!

I have since heard active Naim SL2s, which are very good, and am able to "reference" the briks to those to some degree, and I know the 'operation' has been a great success.

And a tremendous sense of personal satisfaction at doing it.

Go on - you know you want to!

Regards
David

Ps - if you live anywhere near Surrey you are welcome to come and hear them.
 
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