Linkwitz active xover

Systems

Im upgrading the active crossover for the mid-tweeter section in my fully active 3way with one of S Linkwitz's MT boards. (The 300hz woofer -mid xover is handled by a Bryston 10B LR).As the name suggests he is the codeveloper of the Linkwitz-Riley crossover alignment which is in all probability the most oft used crossover topology in commercial and DIY speakers.Not surprisingly the board was designed for 24db L-R slopes , I will set mine at 2.1k.
The PCB also has provisions for adding electronic time delay to the tweeter section if necessary. I won't be needing this feature as I have used a slanted baffle to time aligned the midrange and tweeter.

Other features will include.

-Panasonic Polyprop caps in the filter sections
-Premium audio grade op amps,National's LM4562
-Discrete low noise voltage regulators(stolen from my BB1792 DAC)
-No input or output coupling caps
-CONNEX gold RCA' connectors
-DH Labs Silver Sonic signal wiring
-Outboard 100VA toroid transformer(too big to fit into chassis)
-Bourns 91series conductive plastic pots for hi pass level adjustment.

treitz3

When will you get it?

Systems

treitz3 wrote: »

When will you get it?

get what?

treitz3

The active x-over.

Face

Too bad you're too far away for me to hear the finished product.

Systems

treitz3 wrote: »

The active x-over.

That is the partially completed unit in the thumbnail,I have much soldering left to do.

ShinAce

Face wrote: »

Too bad you're too far away for me to hear the finished product.

aside: He already runs 3-way active(afaik). He's just swapping out a section or two.

Road trip?

ben62670

I used the Marchand electronics boards. They were $50 a pair of 2 way kits with the 24db L-R slopes, and came with all the parts including 6 OPA2134 OpAmps. Is there any particular reason you choose the board you are using? Is it a border thing? The Marchandelec kits are a steal.
Thanks
Ben

treitz3

GV#27 wrote: »

That is the partially completed unit in the thumbnail,I have much soldering left to do.

Ah, 10-4.

ShinAce

p.s. Nice case! That is heavy duty, certain!

Rack mount? If yes, you're a beast.

Systems

ShinAce wrote: »

. He's just swapping out a section or two.

Yes Im just upgrading this section,the xover I'm removing will be used for experimenting with active 2 ways.

Road trip?

Sure your only 3.5-4 hrs away.

Systems

ShinAce wrote: »

p.s. Nice case! That is heavy duty, certain!

Rack mount? If yes, you're a beast.

Yes I will be using the same 19" rack mount front panel that I used on my 1792 DAC.It is a blank panel from Hammond.

Systems

ben62670 wrote: »

Is there any particular reason you choose the board you are using?

I really liked the layout and having the on board allpass delay option is nice,though I won't be needing it in my current configuration.

The Marchandelec kits are a steal.
Thanks
Ben

An absolute steal and the best deal by far in active kits.I don't know how he makes any money at those prices.

Systems

I have the unit completed and operational.Thankfully it passed the smoke test.It's early days but I believe it offers an improvement in the areas of detail retrieval and soundstage width and depth vs the one it is replacing.

ben62670

Cool. Very cool. I heard major improvements going from a cheap active XO to the dedicated Marchand XO. Do you have any nude pics of the PS? I need to get my PS up to date. Are you doing the recitation inside the PS? I see you have the regs inside the XO box.

Systems

ben62670 wrote: »

Do you have any nude pics of the PS?

No,it just has a 100va toroid and a Corcom AC line filter.

Are you doing the recitation inside the PS? I see you have the regs inside the XO box.

Rectification and filter capacitance is contained on the reg board's.

ben62670

Which caps are you using on in the XO, and why. Inquiring minds want to know:)

Systems

ben62670 wrote: »

Which caps are you using on in the XO, and why. Inquiring minds want to know:)

I listed them in the first post.Panny P series polyprop's from Digi Key.

ben62670

These?
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P3223TB-ND
The 2% are very cheap.

Systems

Thats them.I tested and matched the 22 pieces I purchased and all except 3 were the same value.The other 3 were a mere 1% smaller.


I have also used the EPCOS polyprop's in filter sections ,also from Digi key.

Systems

ben62670 wrote: »

.. and why.

Sorry forgot to answer this.


Mainly beause of the price -performance ratio and SL lists them for use in his boards.I have used Panny film caps in many previous projects and have had nothing but positive results.I have also seen them used in hi end commercial offering's ie. Pass Aleph P preamp.

soiset

GV#27 wrote: »

Im upgrading the active crossover for the mid-tweeter section in my fully active 3way with one of S Linkwitz's MT boards. (The 300hz woofer -mid xover is handled by a Bryston 10B LR).As the name suggests he is the codeveloper of the Linkwitz-Riley crossover alignment which is in all probability the most oft used crossover topology in commercial and DIY speakers.Not surprisingly the board was designed for 24db L-R slopes , I will set mine at 2.1k.
The PCB also has provisions for adding electronic time delay to the tweeter section if necessary. I won't be needing this feature as I have used a slanted baffle to time aligned the midrange and tweeter.

Why did you use a slanted baffle instead of a stepped baffle?

Systems

soiset wrote: »

Why did you use a slanted baffle instead of a stepped baffle?

The biggest reason was cosmetic,I like the slanted look better.Aswell the protrusion of the step would create a reflective surface below the tweeter.

soiset

GV#27 wrote: »

The biggest reason was cosmetic,I like the slanted look better.Aswell the protrusion of the step would create a reflective surface below the tweeter.

Yeah, the slant looks good, and high-end, like that Usher Tiny Dancer speaker. And without the time-delay, you get lobing toward the farther-recessed woofer, which means the in-phase response is horizontal.

I'm going to be starting my own active speakers soon, with a very similar design. The crossover will be modified Rane AC-22's (modified to remove the DC-blocking caps and infrasonic filters, as well as to change the woofer delay to a tweeter delay). I'm still working on the driver selection, but when I get the design down pat, I plan to build 9 of them for HT use. Later, I'll build a two-channel pair that will use a second cab below each, similar to your design, to hold the subwoofers (crossed at about 80 Hz).

I figure an active design will allow the use of lesser loudspeakers with results equivalent to using much more expensive drivers with passive xovers.

ben62670

soiset wrote: »

Yeah, the slant looks good, and high-end, like that Usher Tiny Dancer speaker. And without the time-delay, you get lobing toward the farther-recessed woofer, which means the in-phase response is horizontal.

I'm going to be starting my own active speakers soon, with a very similar design. The crossover will be modified Rane AC-22's (modified to remove the DC-blocking caps and infrasonic filters, as well as to change the woofer delay to a tweeter delay). I'm still working on the driver selection, but when I get the design down pat, I plan to build 9 of them for HT use. Later, I'll build a two-channel pair that will use a second cab below each, similar to your design, to hold the subwoofers (crossed at about 80 Hz).

I figure an active design will allow the use of lesser loudspeakers with results equivalent to using much more expensive drivers with passive xovers.

I love the active speakers. I used Marchand electronics XO's. 24db LR slopes, but no timing on them. A pair of 2way boards is only $50 with BB/TI OPA2134 opamps, and all good parts minus the trim to adjust the bump/dip at the XO point. If figured what I wanted and replaced the pot with the correct value resistor. I may be making a custom board with 3 ways XO's, time delay, and an EQ for the sealed subs I am running in my 3 way SDA's. LMK if you have any interest.

soiset

ben62670 wrote: »

I love the active speakers. I used Marchand electronics XO's. 24db LR slopes, but no timing on them. A pair of 2way boards is only $50 with BB/TI OPA2134 opamps, and all good parts minus the trim to adjust the bump/dip at the XO point. If figured what I wanted and replaced the pot with the correct value resistor. I may be making a custom board with 3 ways XO's, time delay, and an EQ for the sealed subs I am running in my 3 way SDA's. LMK if you have any interest.

You used a resistor to correct the bump/dip at the xo point? How did you do that? That is my only remaining concern, and I don't want to use an EQ to solve it.

ben62670

http://www.marchandelec.com/xm1.html
This is the kit I used. There is a link to the manual. Also I hard mounted the XO resistors instead of using the socket. Same with the OpAmps. I knew what value I wanted from experimentation.

Edit: I also hard wired the wires instead of using the terminal blocks.

Systems

soiset wrote: »

And without the time-delay, you get lobing toward the farther-recessed woofer,

Exactly.

I'm going to be starting my own active speakers soon, with a very similar design. The crossover will be modified Rane AC-22's (modified to remove the DC-blocking caps and infrasonic filters, as well as to change the woofer delay to a tweeter delay). I'm still working on the driver selection, but when I get the design down pat, I plan to build 9 of them for HT use. Later, I'll build a two-channel pair that will use a second cab below each, similar to your design, to hold the subwoofers (crossed at about 80 Hz).

Wow 9 active channels,thats very ambitous.What are your plans for amplification?Gainclones?

I figure an active design will allow the use of lesser loudspeakers with results equivalent to using much more expensive drivers with passive xovers.

Since going completely active I'm convinced it has many performance advantages vs the passive approach but the downside is the added complexity.

soiset wrote: »

You used a resistor to correct the bump/dip at the xo point? How did you do that? That is my only remaining concern, and I don't want to use an EQ to solve it.

The particular config Marchand uses allows for a pot to be used for adjusting the damping at the crossover frequency.

soiset

GV#27 wrote: »

Exactly.Wow 9 active channels,thats very ambitous.What are your plans for amplification?Gainclones?

Don't laugh, because I've had very good results with them: Rane amps. The Rane MA6s is six channels at 150 wpc into 4. The Rane MA3 is three of 60 into 4. I have two of the MA6s amps and 4 of the MA3. So I can go 12 channels if I want to. They are actually pretty good amps. All channels are independently gain-adjustable, and the specs are quite good. Rane actually marketed a re-badged MA6s (called the SS6) with RCA inputs as a home theater amp, for a while. The downside (for most) are the fans, but I'll have my stack o' amps in a closet. The subs will be driven by a Crown MA1200 if I don't swap it out for the slightly less roadworthy but more powerful Microtech 2400.

The Rane crossovers have been very handy, and sound great without the mods, but they are simple, so I'll do them (especially for adjusting the delay of the tweeter).

The two channel is all Rotel, though. I'm kinda regretting selling that RB991 a while back, because it would be so nice for the stereo subs that will go there (same gain as the 971 and 981 I have currently biamping my setup).

My HT pre is a Sunfire TGP3, and Rane's guys all came from Carver (they still aren't far apart) so I kinda like to think I've kept it all in the family. The MA6s was a $1200 amp, new, but with the fan and lack of audiophile name, you can pick them up for less than $300 in great shape. I'm ashamed to say how cheap the MA3 has been going for on ebay lately.

I might use all Dayton loudspeakers in the HT. That silk dome 1-1/8" is supposed to be really good. Should be able to come in at less than $60/speaker for the drivers. Haven't decided on the 2-channel pair components. I'd like to stick to a budget of $300 for the loudspeakers in those.

Systems

soiset wrote: »

Don't laugh, because I've had very good results with them: Rane amps. The Rane MA6s is six channels at 150 wpc into 4.

No laughing here.Going active places less of a burden on the driving amplifier because of the restricted bandwidth it will be reproducing and the easy load, just the driver itself (no reactive xover components).IMO good results can be had with less expensive amplifiers.6X 100w in one chassis is certainly attractive.

I might use all Dayton loudspeakers in the HT. That silk dome 1-1/8" is supposed to be really good.

The Dayton stuff is hard to beat for value and performance.

ben62670

The 6.5 inch Silver Flutes at Madisound are great sounding speakers that can handle power well. At $25 each they are a steal. They make the Polk MW's look like toys. Cast frames, wool cones, and rubber surrounds. I have the 5.5" Silver Flutes in mine, but the weird thing is they don't voice the same as the 6.5's, and are petite looking compared to the 6.5's.