A how to for a PC XO.

[Thunau]

Here is a pretty advanced software crossover.
4-way (or more if multiple instances are used) up to 42dB/oct slopes, response graphs, measurements importing, EQ, delay, etc- it's all there.
All you need is a PC with multichannel ASIO sound card and $59.00.
No excuses if you can't make your speakers sound right with this cossover.

Check it out at
http://www.thuneau.com/alloclite.htm ] http://www.thuneau.com/alloclite.htm [/URL]

Yes, it's my website, but there isn't really anything out there that gives you this much power when it comes to software DSP crossovers for so little money.
So, while it's admittedly a shameless plug, it's an honest advice at the same time.
I developed this software because there was nothing like it available and I wanted these features in a software crossover.

[Emiel]

I've been reading most of this thread now, very interesting. Thanks for all the usefull info, especially ShinOBIWAN.

I'm looking for a new soundcard and I stumbled upon the Terratec Phase series. Would this PC XO work with e.g. the Phase 28?

http://audioen.terratec.net/modules....ticle&artid=25

Kind regards,

Emiel

[ShinOBIWAN]

Originally posted by Emiel
I've been reading most of this thread now, very interesting. Thanks for all the usefull info, especially ShinOBIWAN.

I'm looking for a new soundcard and I stumbled upon the Terratec Phase series. Would this PC XO work with e.g. the Phase 28?

http://audioen.terratec.net/modules....ticle&artid=25

Kind regards,

Emiel

Hi and thanks,

Yes that would work very nicely with Thunau's Frequency allocator. I would no longer recommend the Console/Waves route because a new and better solution is available.

Thunau has demo's of all his products available from his website and very reasonable prices too.

[Daveis]

I agree that the Thunau FreqAllocator should, perhaps, be the first starting place for those wanting to do crossover functions on a Windows PC. I look forward to refinements of the program. The one I'm most interested in is a way to swith the Allocator into a super low latency mode (eg. like Allocator lite) for home theatre/DVD use.

I am going to begn experimenting wih partial digital/passive crossover.

The only issue I see with using the Thunau stuff is you still need to complement it with measurement tools. I havent found a good system for measuring MLS response, etc.

In particular, I need a good 48volt mic preamp and A/D convertor with AES/EBU outputs.... anyone know of something? And I'm also finding that an uncalibrated ECM8000 Behringer Mic isnt enough for serious measurements.

[Thunau]

Yes, it looks like a very good candidate for the Allocator Light. It has ASIO drivers, 8 outputs and digital I/O.
I said Allocator Light because I could not find the ASIO buffers descriptions for it. If it has the option to set them to 1024 or more, you should be able to run the Allocator with no problems.

The only thing of possible concern to users might be the cabling.
The break out connector uses TRS (tip ring sleeve) 1/4" connectors. The signal is balanced and from what I can find on their website- set to 0dBV nominal output level. That means it's on the hot side. You would need extra 10 dB of attenuation to make it work with consumer style hi-fi amps that have RCA inputs.

The Terratec Phase 88 has a nice break out box with RCA outputs that can be set to output -10dB signal and you don't have to get behind the computer to make connections. That one looks like a very nice interface for use with crossover software. I know it's much more costly, but you get the convenience and features that make it very good for the application.

[Thunau]

Originally posted by Daveis
I agree that the Thunau FreqAllocator should, perhaps, be the first starting place for those wanting to do crossover functions on a Windows PC. I look forward to refinements of the program. The one I'm most interested in is a way to swith the Allocator into a super low latency mode (eg. like Allocator lite) for home theatre/DVD use.

I am going to begn experimenting wih partial digital/passive crossover.

The only issue I see with using the Thunau stuff is you still need to complement it with measurement tools. I havent found a good system for measuring MLS response, etc.

In particular, I need a good 48volt mic preamp and A/D convertor with AES/EBU outputs.... anyone know of something? And I'm also finding that an uncalibrated ECM8000 Behringer Mic isnt enough for serious measurements.

For HT use there is no way to switch the Allocator into a super low latency mode. But there is a way of delaying the video signal to align it with the Allocator's audio stream.
You just have to use a good DVD playback software. On my board someone brought up the FDshow dll that is a free download and apparently adds this functionality to any software player.
One thing to keep in mind though is the CPU load. You will need a very good machine to keep up with DVD decoding/playback and multiple instances of Allocator.
Perharps a fast dual processor machine like the new dual cores would be enough.

[dwk123]

Originally posted by Daveis
[B]I agree that the Thunau FreqAllocator should, perhaps, be the first starting place for those wanting to do crossover functions on a Windows PC. I look forward to refinements of the program. The one I'm most interested in is a way to swith the Allocator into a super low latency mode (eg. like Allocator lite) for home theatre/DVD use.

That's actually a pretty good idea. I'm not sure how easy it would be to implement, but it would make it easier to get 'one stop shopping'.

The only issue I see with using the Thunau stuff is you still need to complement it with measurement tools. I havent found a good system for measuring MLS response, etc.

I use SoundEasy to measure 'through' Allocator, and it mostly works ok. The big issue I'm having I believe is due to the Emu drivers and not anything to do with Allocator, which is that latency is wildly unpredictable from measurement to measurement. Makes it really tough to look at time alignment. I'm planning to swithc measurement over to an M-Audio card, but then Allocator won't be in the loop. However, it should at least allow me to get solid reference FRD's that are normalized.

In particular, I need a good 48volt mic preamp and A/D convertor with AES/EBU outputs.... anyone know of something? And I'm also finding that an uncalibrated ECM8000 Behringer Mic isnt enough for serious measurements.

What problems are you finding with the ECM8000? And, I guess how can you tell if you don't have a 'good' pre with phantom power? My take is that it's pretty good uncalibrated up to about 10k or so, and above that I consider things to be 'adjust to taste' anyway.
A good standalone A/D with AES/EBU out will probably be somewhat pricey.. The only cheap one I know of in production (I think) is the M-Audio 'flying cow', which appears to have AES/EBU out, but only goes to 48k. I have a Symetrix 620 that does both AES/EBU and spdif out, but once again limited to 48k and it's been discontiued for quite a while.
PreSonus has a combination mic pre +A/D converter (the DigiTube) but it's spdif only. You can probably use a transformer to feed it into an AES input, though.

[Thunau]

Originally posted by dwk123

That's actually a pretty good idea. I'm not sure how easy it would be to implement, but it would make it easier to get 'one stop shopping'.

See above. No way to put the full Allocator into a low latency mode. That's the reason Allocator Light exist.

Originally posted by dwk123
I use SoundEasy to measure 'through' Allocator, and it mostly works ok. The big issue I'm having I believe is due to the Emu drivers and not anything to do with Allocator, which is that latency is wildly unpredictable from measurement to measurement. Makes it really tough to look at time alignment. I'm planning to swithc measurement over to an M-Audio card, but then Allocator won't be in the loop. However, it should at least allow me to get solid reference FRD's that are normalized.

If you wanted to just confirm the combined frequency response you could open the preset saved in Allocator in Allocator Light (the preset files are compatible). This way your measurements would not have the extra delay in them.
If you wanted to confirm the phase as well, you have to use the Full allocator and deal with the latency issues.
I guess I really should look into a measurement tool specifically written for use with the Allocator.
Maybe after the next product that's coming up is finished.

Originally posted by dwk123
What problems are you finding with the ECM8000? And, I guess how can you tell if you don't have a 'good' pre with phantom power? My take is that it's pretty good uncalibrated up to about 10k or so, and above that I consider things to be 'adjust to taste' anyway.
A good standalone A/D with AES/EBU out will probably be somewhat pricey.. The only cheap one I know of in production (I think) is the M-Audio 'flying cow', which appears to have AES/EBU out, but only goes to 48k. I have a Symetrix 620 that does both AES/EBU and spdif out, but once again limited to 48k and it's been discontiued for quite a while.
PreSonus has a combination mic pre +A/D converter (the DigiTube) but it's spdif only. You can probably use a transformer to feed it into an AES input, though.

I think that all you need is a mic preamp in the audio interface. The M-audio 410 has it, the Presonus Firebox has it, the Emu 1820 has it.

Are you running into problems acessing yours from two applications simultaniously?

[Daveis]

Originally posted by Thunau


See above. No way to put the full Allocator into a low latency mode. That's the reason Allocator Light exist.

Are you running into problems acessing yours from two applications simultaniously?

For the folks that purchased Allocator, it would be a nice extra to bundle in Lite for those times you needed to watch a movie. Does a full Allocator purchase entitle the user to use Lite? I'm fuzzy on that.

I think I'll look into a MAudio Flying Cow. I thought those were discontinued, but I know you can still find them.

My main complaint with the uncalibrated ECM8000 was indeed it's questonable response above 10Khz.

[Thunau]

Originally posted by Daveis


For the folks that purchased Allocator, it would be a nice extra to bundle in Lite for those times you needed to watch a movie. Does a full Allocator purchase entitle the user to use Lite? I'm fuzzy on that.

Yes, that is the plan with the release of 1.0. But I will provide all the owners of Allocator 0.10.1 with a serial for the light version retroactively.