The Splitter Channel

[Jim vanBergen]

Originally Posted by DRC

Im using the passive crossovers in the speakers. I would think that hitting the each power amp with the line level signal at the same time (via a 3-way "y" cable) would yield better results that going through more connections, transformer outs, and what ever else might be involved with chaining amps.

Is this how you Triamp your system? What are you using? Results?

I use Hafler 1500s for my Dynacoustic monitors (rock mixes), Crown DC300s for my Tannoys (my most neutral, phase-shift free monitors), and then the rest (broadcast, classical and theatre mixes) are all self-powered Genelecs.

I like active crossovers like XTA and BSS when I need to use them. The most important thing to me is that the speakers sound ACCURATE, either the best the manufacturer can make them sound, or the best they can sound while being sonicly correct and accurate from phase response, frequency & amplitude.

If I were you, I'd contact the manufacturer of the speakers and find out exactly what THEY suggest you do for wiring. While a three-way Y is fine, it will change the impedance of the line level (no longer 600 ohms) which means that the mix will translate differently on other speakers. THAT is my primary concern. If it were MY gear, I'd either use an external crossover (like an XTA DP226 with L/M/H out) for distribution unless I had amplifiers that utilized an electronically balanced, buffered pass thru of the input signal (like many Crown amps have.) But its YOUR call!!!!

Hope this helps!!!

[DRC]

Originally Posted by Jim vanBergen

If I were you, I'd contact the manufacturer of the speakers and find out exactly what THEY suggest you do for wiring. While a three-way Y is fine, it will change the impedance of the line level (no longer 600 ohms) which means that the mix will translate differently on other speakers. THAT is my primary concern. If it were MY gear, I'd either use an external crossover (like an XTA DP226 with L/M/H out) for distribution unless I had amplifiers that utilized an electronically balanced, buffered pass thru of the input signal (like many Crown amps have.) But its YOUR call!!!!

Hope this helps!!!

I did speak with a guy from PMC about it, and demoed the pair that way as well. Passive Triamping sounded very accurate. I like where the internal crossovers are set, I just need a way to get the same signal there. I will definately take the line level impedence issue into consideration.

Thanks for the input Jim.

[Jim vanBergen]

Happy to provide an opinion; I just I hope my opinion helps.

I'd go with the manufacturer's specification/recommendation. If you liked the way it sounded in a specific location/installation, find out how THEY did it and do that. Best to be sure, right?

[mpdonahue]

Originally Posted by Jim vanBergen

If I were you, I'd contact the manufacturer of the speakers and find out exactly what THEY suggest you do for wiring. While a three-way Y is fine, it will change the impedance of the line level (no longer 600 ohms) which means that the mix will translate differently on other speakers. THAT is my primary concern. If it were MY gear, I'd either use an external crossover (like an XTA DP226 with L/M/H out) for distribution unless I had amplifiers that utilized an electronically balanced, buffered pass thru of the input signal (like many Crown amps have.) But its YOUR call!!!!

Jim, I don't think that there will be any loading issues feeding the inputs of 3 modern power amplifiers with bridging inputs from a modern low impedance source. Most modern amps have a 20k or 50k ohm input loads. It would take about 15 or 20 parallel inputs to get down to 600 ohms.

All the best,
Mark

[bennals]

G'day.

I hope I'm putting this post in the right place. I've looked through a lot of the posts about splitters and haven't found exactly what I'm looking for so I thought I'd give it a go here.

I'm pretty much a novice when it comes to electronics. I've done plenty of soldering on mic leads and the like but don't really know much about the underlying theories of, for example, a passive isolated splitter box. Anyway, I'm just starting to get into mobile recordings and figure one way to learn more about these things and get something useful out of it at the same time would be to build a 16 channel splitter box.

So, I've bought my transformers (Crimson Audio 2 way split) and got my case sorted. I've also read through the Jensen notes on construction as well as a few other documents and now I have a few questions.

1. The Jensen article refers to an RF network consisting of a 51 ohm resistor and 10 nF capacitor. Do people generally agree this is an important feature of a good quality spliiter box?

2. The article also suggests soldering a 2k7 resisitor across pins 2 and 3 on the isolated outputs if there is a possibility that any of the isolated outputs will not be used. I'm guessing that means that in a three way split with two isolated outputs, only using one of the isolated outputs might cause problems that the 2k7 resistor is intended to address. I'm also guessing that because I've only got two way splits and the isolated split will always be used (otherwise I'd remove the splitter box altogether) that it won't be required for this design. Is this correct?

3. I noticed that on the photos of a Crimson Audio splitter box that John sent me there is a chassis ground lug on the case. What would this lug ideally be connected to?

The other thing that I would really like to find is some good, detailed close-up photos of the wiring internals of splitter boxes people have made. I think it would help me to understand the schematic diagrams in the Jensen article more thoroughly. Like for example, how people have implemented the RF network.

Any help I can get would be greatly appreciated.

Cheers.

Bill.

[idave]

Hey Steve, I would like some advise on the following and many thanks in advance for any and all given!!
My rig is based around (2) HD24's (3) Octopre's with adat cards (3) Crimson 8ch splitters with DIR + ISO outs, WC=Apogee Big Ben, pwr conditioning=Furman AR1215 and a UPS also the Roland M-480 for Monitoring the HD24's. I have to say that a lot of great information came from you and the guys on this board so thnx all for the great pearls of wisdom!! I designed and Elco/Elco multipin system to connect everything together, the elco system was built by Roger Cane of Cane Audio Systems on Staten Island and I am really impressed with his work etc!!
My system is designed primarily as a 24 track with 24 trk b/up recorded 24bit/48k wired as follows;-
mic-->crimson split-----> ISO------->Octopre-----> as the Octopre's have dual litepipe outs (for s/mux when recording at 88.2 or higher etc!) but at 44.1/48k they are a "mirror" image of each other (all this I am sure you are aware!!) so I take (1) litepipe to HD24.Main and the other litepipe to HD24 B/up so as long as the mic's don't fry, Octopre's frazzle or litepipe cables crash (Huh!!) I have a mirror back up of 24trks!!
I have a client who is considering renting my rig to take on a european tour and he will be doing double duty FOH & Recording the band (a very brave man indeed!!) I have all my delicate gear in an 16sp Anvil type shock rack and the M-480 + 4 space drawer in a 10sp SKB US Roto Rack (the new models) and the 24 ch's of Crimson splitters + 4 sp drawer in a 2nd SKB US Roto Rack all patched together with (3) elco/elco snakes (gorra love that!!)
Although for this tour I am in wondering wether to rack up the Mixer/Splitters in a 2nd 18 sp shock rack that I have as long as the FOH/Record guy doesn't mind having the splitters at the FOH position along with the pre's and HD24's of course which would mean taking his main FOH feed and splitting it at the FOH position with my Crimson Splits ----> DIR to him and ----> ISO to my rec rack, do you see any problems with this scenario?

Sorry for the long posting but I wanted to give you as much info as poss. I promise to post some pics soon as possible of my rig etc!!

cheers
dave

[Mick@itc]

Guys...

I am excited by this thread and would just love if we could develop a design for a 24 channel splitter with wiring connections and components specificed/suggested. I would certainly like to build one over time. It would be great for a few of us to do it and compare notes...

So what I am asking for is someone who knows what they are doing to draft up a list of parts and wiring instructions for the "best" passive splitter as defined by people like Steve and the experienced guys here.
WHATYATHINK??
Mick

[tnjazz]

Originally Posted by Mick@itc

So what I am asking for is someone who knows what they are doing to draft up a list of parts and wiring instructions for the "best" passive splitter as defined by people like Steve and the experienced guys here.
WHATYATHINK??
Mick

Just make sure you buy good parts and you'll be fine (Neutrik connectors, etc). Here's a recipe for you.

6 space rack case
3 x 24 XLR punched panel from Redco
24 panel mount XLR female connectors
48 panel mount XLR male connectors
~200 feet of rack wire (Gepco or similar)
2 XLR to XLR 24 channel snakes, any length you can afford

Connect all panel mount XLRs to their respective panels. Number each with a silver sharpie (or similar) on the inside for future soldering reference.

Cut 48 lengths of 4 ft or so. Strip, twist, tin 2 of each together to form 24 pairs. Strip and tin the two opposite sides as well.

Solder joined ends to female panel mounts. drains to 1, reds to 2, blacks to 3. Repeat with single ends to male panel mounts for each of the 24 channels.

Screw panels into rack case. Number the inputs and outputs on the outside of the panels. I use a labelmaker. The black tape blends in very well and is a whole lot cheaper than screening or engraving.

Zing! Boom! Voila! One simple 24 channel passive splitter at your service.

I make my splitters this way, although instead of 48 male XLR panels I wire all the ones I make to Elco/EDAC connectors for quick disconnects. A lot more time consuming to make, but it saves a lot of time in the field.

[Mick@itc]

Originally Posted by tnjazz

Just make sure you buy good parts and you'll be fine (Neutrik connectors, etc). Here's a recipe for you.

6 space rack case
3 x 24 XLR punched panel from Redco
24 panel mount XLR female connectors
48 panel mount XLR male connectors
~200 feet of rack wire (Gepco or similar)
2 XLR to XLR 24 channel snakes, any length you can afford

Connect all panel mount XLRs to their respective panels. Number each with a silver sharpie (or similar) on the inside for future soldering reference.

Cut 48 lengths of 4 ft or so. Strip, twist, tin 2 of each together to form 24 pairs. Strip and tin the two opposite sides as well.

Solder joined ends to female panel mounts. drains to 1, reds to 2, blacks to 3. Repeat with single ends to male panel mounts for each of the 24 channels.

Screw panels into rack case. Number the inputs and outputs on the outside of the panels. I use a labelmaker. The black tape blends in very well and is a whole lot cheaper than screening or engraving.

Zing! Boom! Voila! One simple 24 channel passive splitter at your service.

I make my splitters this way, although instead of 48 male XLR panels I wire all the ones I make to Elco/EDAC connectors for quick disconnects. A lot more time consuming to make, but it saves a lot of time in the field.

No Isolation transformers...I thought that would not be a good solution for mic level signals???

[tnjazz]

Originally Posted by Mick@itc

No Isolation transformers...I thought that would not be a good solution for mic level signals???

You want transformers in your splitter? Wire them in between the XLRs then. Jensen, Lundahl and Sowter are typically considered the "best". You'll pay a premium for that though (about $100 per unit)

I have a 3 way transformer iso split and I never use it, so I don't really buy into the need for that isolation. For all the shows I do I just use the 24 channel 2 way I built and it works just fine. Never had any problems with it. As long as you do your due diligence on the front end (line checks, etc) you should be just fine. Running in parallel will cause about a 3db drop in signal on both ends, but I've never found that to be a major issue (either for recording OR for the FOH guys).

[mpdonahue]

Couple of quick comments:

What some are calling "passive splits" are anything but a splitter. Where I come from splitters provide isolation. If there is no isolation then they are nothing more than a "Y" cable and for mic level are a recipe for disaster. You could do this a lot cheaper and faster with a fistful of Dsub 25 pin IDC connectors and a roll of ribbon cable. Combine this with 3 Hosa 25 pin to XLR and you have a " splitter". It still is a patently bad idea for mic level sources, especially those using phantom power. I'm sure that there are those that will say "it worked fine for me" but the additional loading and attendant drop in level and increase in distortion, hum, buzz, frequency response aberrations and all the other things that come from non-isolated microphone splits make me run for the hills.
A passive splitter is a transformer, not a Y cable.

WRT the 51ohm/10 nF filter, this is probably the most important thing in the Jensen application note. The reason most people need to connect grounds on a transformer isolated splitter is because this is not present. In the splitters I build I put these components directly on the XLR connector before I even start wiring the chassis. It is easy to put the components between the lug and pin 1 so that they sit along the side of the connector shell, out of the way. If you back mount your connectors you can do this on the bench, rather than with the connector mounted in the panel.

One of the things I've thought about doing is laying out a PC board to use the transformers with PC mounts rather than those with flying leads. Maybe if I get a couple of days off this winter I'll sit down and do it.

All the best,
-mark

[DRC]

If I am just splitting line level, post preamp, would something like this: Violet Audio - Home be just fine? Has any one heard of any quality issues with this company?

The DX16XI has no transformers but the outputs of my pres and channel strips all do (minus my GML's). I just want to send the signal straight to the recorder without having to go through a cheap monitor mixers direct outs. What is the point of tracking with a GML pre just so you can run it through a Mackie on the way to the recorder?

[Mick@itc]

Originally Posted by DRC

If I am just splitting line level, post preamp, would something like this: Violet Audio - Home be just fine? Has any one heard of any quality issues with this company?

The DX16XI has no transformers but the outputs of my pres and channel strips all do (minus my GML's). I just want to send the signal straight to the recorder without having to go through a cheap monitor mixers direct outs. What is the point of tracking with a GML pre just so you can run it through a Mackie on the way to the recorder?

I live down the road from them...will check them out and let you know.
Mick

[NorseHorse]

Helloo Steve and fellow GSers,

Thus far, I've done very few shows that needed splits, but I anticipate more, so I'm checking out my options. I've looked over a few threads and gleaned some good info. But I also have a question. Someone mentioned having mic pres on stage and the splitter AFTER these. So...

Can run-of-the-mill XLR splitters (like the ART S8 or Horizon MS4) handle both mic levels and line level signals?

The S8 is advertised as an "XLR splitter" while the Horizon has "mic splitter" written right on it.

[Mick@itc]

Originally Posted by DRC

If I am just splitting line level, post preamp, would something like this: Violet Audio - Home be just fine? Has any one heard of any quality issues with this company?

The DX16XI has no transformers but the outputs of my pres and channel strips all do (minus my GML's). I just want to send the signal straight to the recorder without having to go through a cheap monitor mixers direct outs. What is the point of tracking with a GML pre just so you can run it through a Mackie on the way to the recorder?

Just bought one of the DX16I's and will post some sample files through it ,straight cable and a EWI splitter. Initial physical impressions..very solid...heavier than I thought...looks the goods and a good price.

Give me a week or so and I will post an opinion and samples.

Mick