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Is anyone using a ULN8 as an active crossover ?


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Steve,

 

So if I understand this correctly it looks like the better pros use a similar process to what we use for the DEQX. Measure the speakers in a near anechoic environment, apply correction to the speakers then place them in the room and then using a combination of speaker placement and EQ correct the in room response. And in the pro's case time alignment of multiple sources.

 

Thanks for insight

 

Mark

 

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Hi Nyal,

 

Thanks for all the research material. This will keep me busy for hours following up on all this information.

 

I am not sure if you have had time to look over here http://www.mhsecure.com/technotes/v5MixerOverview/MIO+DSP_Plugin_Index/index.html but this link will take you to a list of many of the standard plugins that come with the ULN8 under the DSP+ license.

 

For crossovers and speaker correction you might start with the (1) 6 and 12 band parametric EQ's that contain high pass, low pass, cut boost, band pass, high and low self filters (2) delay (3) mixer (4) band split primitive which provides Linkwitz-Riley filters - see Steves post above. I have yet to track it down but I expect there is a way of adjusting phase. I am sure I read in MH's literature that phase is automatically corrected when the DSP+ plugins are used so manual phase correction may not be required. Only measurement will tell.

 

So I would not say that the ULN 8 /Model 305 is not designed to do crossovers and speaker correction. It may be more correct to say that it is not its primary function.

 

One big advantages of using the DSP+ plugins is that once you have built the required template (that may not be the right technical word) they can be down loaded from the computer into the ULN 8 / Model 305 which can then be run in stand alone mode. In fact 8 or 9 different templates can be downloaded to the ULN 8 / Model 305.

 

Of course you will still need your computer if you are using it as your music server but then the only load on the computer will be audio playback. I will let others argue about wether that is important or not, but the option is there.

 

At this stage the MIO console does not support third party AU plugins. I currently have very little knowledge about plugins but I understand you need to run a DAW to be able to use other plugins and the DAW can then send the processed signals though the console to the ULN 8 / Model 305. The downside to this is that the computer is used to process all this whilst also working as a music server.

 

Of course all this is Mac based. Which brings us to what I see as potentially the biggest downside of the ULN 8 / Model 305. It is Mac only. Not only doe this mean you can't run the MIO console on a widows based computer, there is not even a driver to allow you to run a windows based music server to the ULN 8 / Model 305 via firewire.

 

As yet I have yet to find a similar piece of hardware that does what the ULN 8 / Model 305 does. The Prism Orpheus has the firewire interface, 8 AD and DA channels and it has drivers for both mac and windows. To me the downside to the Prism is that its on board DSP is limited to mixer functions. Not an issue if you do not want to download correction filters onto the unit to run in stand alone mode. But for me I would prefer to do without the windows interface.

 

But for anyone who wants to focus on windows based crossover and correction software this might be the way to go. I can not comment on the quality of the sound from either as I have not heard either, but they both seem to get favorable reviews. (please lets not start a war here on the respective sound quality of the 2 units)

 

Of course I do have a work around for trying windows based programs. I already own a Lynx AES 16e. So I put the Lynx into my windows computer and just send the 6 channels out via AES/EBU to the digital inputs of the ULN 8 / Model 305.

 

I have no idea which software will work and sound best for me (native DSP+ plugins, windows based ...) but I think I have enough flexibility with the ULN 8 / Model 305 to keep me amused for quite a long time.

 

Particularly with all the stuff I must learn about along the way.

 

 

Regards

 

Mark

 

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All the Metric Halo plugins run in the DSP chip on board the interface so there is no way to integrate AU or VST plugins. However, Metric Halo provides a plugin for AU, VST and RTAS formats which will embed the configuration (all DSP plugin and routing) information in the host program.

 

So any DAW that runs on a MAc can use its plugin capability to provide custom total recall of any MIO configuration.

 

In addition each MIO has 18 firewire sends to the DAW and 18 DAW returns via the firewire i/o. So there is no reason that you cannot integrate host based plugins with MIO based DSP. In fact many of us in the live sound community use this very configuration to integrate CPU intensive IR plugins and long delays with our MIO based mixers.

 

Steve

 

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Have you managed to integrate a music app like iTunes with a DAW?

 

These things are never so straightforward - for example: I run iTunes into an AU host which has a parametric EQ installed so I can do room correction a la Meridian. However when I put my mac mini to sleep the rerouting app I am using - soundflowerbed - loses the audio interface selection that I have chosen, which means I have to open a VNC connection to reconnect it. Going this route with the metric halo is going to have all these little ergonomic issues that are difficult to work around. Fine for experimenting, not so good to live with on a day to day basis.

 

Nyal Mellor, Acoustic Frontiers LLC.

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You raise a good point but the Metric Halo units do pretty well in this type of app. First off the routing and DSP setup in the Metric Halo DSP is persistent and can be stored as a default boot state. So if your Metric Halo mixer routed DAW1&2 to your EQ and then to your monitoring system you would be all set to go with itunes on launch or restart. If iTunes were your only app then you could put iTunes on your startup list as well.

 

If you also needed a secondary CPU based process to run, you could store the process document in your startup folder and have it launch correctly figured. If it were also an AU host it could launch and configure the Metric Halo DSP as well.

 

This is simply a matter of saving your host document with the Console COnnect AU plugin loaded with the Metric Halo routing set as you like it.

 

So it might not be as bad as you think.

 

Steve

 

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  • 2 weeks later...

Hi Barry,

 

I've appreciated reading your comments and insight into the ULN-8 at this site. In fact, Ive tuned into the MobileIO forum to learn more and enjoyed it. There is no question about the cleverness of the ULN-8 design. My main interest in the unit is as a D/A and preamp, and here my question comes down to the output stage. Since I don't need a lot of the features that you guys do in pro audio, can the ULN-8 stand head to head as a preamp with a really good preamp? The other route I could see going would be a good firewire to AES interface to a used dcs unit. Thanks very much for your input.

 

Tim

 

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Tim - I use it as a preamp and I think it's very good (as analog stage). While it's actual attenuator may not meet the standards of the best audiophile gear, skipping the extra set of connections and step in the signal path was a plus for me (I ended up removing a very good preamp from my signal path and got an improvement in transparency, the Cary slp-05).

 

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Hi Tim,

 

Thanks for your kind feedback.

Regarding your question, in my view, the ULN-8 can do better than "stand head to head" against a really good preamp. I think it can shame many.

 

This however, is just my own perspective. Much depends on what the listener seeks. In my experience, not everyone really wants gear as neutral as they might originally believe. I've often heard folks refer to neutral gear as "dry" and to gear that adds spurious harmonics as "detailed".

 

My suggestion is to audition a unit if you can, using a variety of recordings you know to be good sounding. If you like what you hear, I think you'll find it extends to the preamp function.

 

Hope this helps.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

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Hi silverlight,

 

"While it's actual attenuator may not meet the standards of the best audiophile gear..."

 

The attenuator on the ULN-8 is in its digital logic. The front panel knob is simply an encoder, not a "volume pot".

 

That said, whatever the nature of a component's volume control, it is important to remember it is but one of a very large number of devices the signal must pass through in a component. We listen to the totality and never to just a single device. That of course, is why the '8 replaced your old preamp.

 

I believe it is an effective marketing tool, used on audiophiles (and writers), to cite parts in a component, as if using a certain type of volume pot or using a certain digital converter chip will somehow suggest a certain quality level when the signal passes through these and the thousand other devices within a given component. As if these supersede the importance of the topology itself. As if the best parts make bad sound impossible (something clearly refuted by all too much audiophile gear today).

 

Personally, I'd rather listen to a component from a top designer using "second rate" parts (whatever they are) than one from a hack using "first rate" parts (whatever they are). Of course, giving the top designer the best parts would be ideal but for me, it is the designer (and the design) and not the parts at all. That's why the current chip-of-the-month holds no interest for me.

 

Unless one was to believe the numbers on the spec sheet tell us how something sounds, I don't understand why so many audio writers and 'philes buy into the marketing hype. The only way I know to really be sure of any device's superiority is to put it into the same circuit as another device to which it claims superiority. In the absence of such a direct comparison, we don't know if a volume pot (of digital chip) is better, worse or neither, regardless of what the spec sheets, ads or audio magazine and web site writers (subject to the same spec sheets, ads and other hype) say.

 

(For more, see first post here.)

 

All just my perspective, of course.

 

Best regards,

Barry

www.soundkeeperrecordings.com

www.barrydiamentaudio.com

 

 

 

 

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I am sorry if it was mentioned, but you can use Pure Vinyl as a crossover, you can set it up in its preferences. The Mac will be used for sure doing the number crunching, but can not be to bad. I have never tried so no experience, but I have a DEQX so one day i can PV as well, just for experimenting.

 

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Hey folks

 

Early on in this thread, twist222 said,

 

"Sonic Studio seems to have a good parametric EQ plugin but I am looking for more than jut a good EQ plugin. I expect they do more ?"

 

Yup, more. One of the main differences between Sonic Studio's Model 305 and a ULN-8 is that the 305 includes an extra +DSP module, Sonic EQ. You can read more about it at:

 

http://www.sonicstudio.com/products/hw/soniceq.html

 

All Sonic hardware includes Sonic EQ: Twelve topologies, very adjustable (note that the paramet has 5 controls).

 

Happy crossing!

OMas

 

Regards,

______________________________________________

O.A. Masciarotte - http://www.othermunday.com

______________________________________________

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Oliver,

 

Thanks for the link. My comment on parametric EQ's was very early in the piece, probably before I was pointed in the right direction to understand that both the MH and Sonic eq's can work as high pass, bandpass, lowpass, shelving etc etc filters in addition to peaking eq's.

However it looks like using these EQ's as a starting block will still require a fair amount of manual input to provide time alignment, manual eq for driver frequency correction and potentially phase correction. I had hoped to find some OS X software that was designed for the job. I have been pointed towards windows based software but nothing really for OS X.

 

Have you had the oppertunity to use the Sonic Studio EQ ? If so I would love to hear what you were using it for and your experiences with it.

 

Regards

Mark

 

So

 

 

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Mark wrote:

 

"Have you had the oppertunity to use the Sonic Studio EQ ? If so I would love to hear what you were using it for and your experiences with it."

 

Hey Mark,

 

The current implementation has a wide range of shapes (topologies) as well as a very wide range of control parameters. I mentioned the 5 controls for the paramet, which allows you to trade off group delay for stopband attenuation. Another useful feature is the ability to set a very high Q, up to 100, which is useful for narrow band noise contamination issues like NTSC color subcarrier removal, which appears in more recordings than I care to mention. It's used for everything from timbre "taste adjustments" to problem solving. The latter includes DC/ultrasonic removal, to AES/EBU and RIAA de-emphasis, to the aforementioned speaker crossover.

 

Currently, using a Model Four or a Model 305 for crossover duties is a completely manual process, and requires a bit of geek prowess since the filter type, resonant frequency, slope and gain must all be determined prior to dialing them in. That said, once they're set, those setting can be saved as a preset for recall or further modification.

 

One of my favorite uses for Sonic EQ, a version of which shows up in Amarra, is to "lift a bit of air" in 88.2 and 96 K recordings. What I mean is to provide a bit of gain above 20 kHz, which subjectively adds "air" to otherwise dull or dark recording. I know, not a purist move but, it's pleasant nonetheless.

 

BTW, in the spirit of full disclosure, I'm the marketing guy for Sonic Studio and also an audio engineer. I've been using some form of Sonic EQ since 1990, on everything from classical acoustic recordings, to forensic audio for law enforcement.

 

Regards,

OMas

 

 

Regards,

______________________________________________

O.A. Masciarotte - http://www.othermunday.com

______________________________________________

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  • 3 months later...

Hi Mark (and all others on the thread),

 

I have been looking at active crossovers with or without room correction, too, and the deqx has been pretty high on my list. Have you found and tried a pro-audio alternative to it, yet?

 

Sorry for warming up this old thread,

Martin

 

 

 

Empirical Audio Off-Ramp Turbo 2 -> Accustic Arts DAC 1 Mk. 4 -> AudioZone Pre-T 1 -> EVS M500 -> B&W 802D

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While not a pro option I’ve found this works quite well as tool for finding out what the speakers are doing. http://www.speakerworkshop.com/

Adapting the mic as recommended here http://www.linkwitzlab.com/sys_test.htm is a cheap way of getting reasonable measurements but pretty fiddly.

I have self built active crossovers using linkwitzlab designs but I’ve never tried to control them from a PC. Got me thinking now.

I’ve popped a few drivers experimenting ;)

 

Interesting topic.

 

 

Dedicated Mains Cond dis block. Custom Linux Voyage MPD server. HRT Music Streamer Pro, Linear mains powered ADUM Belkin Gold USB cable. TP Buffalo 11, Custom XLR interconnects/Belkin Silver Series RCA. Exposure 21RC Pre, Super 18 Power (recap & modified). Modded World Audio HD83 HP amp.Van de Hull hybrid air lock speaker cables. Custom 3 way Monitors,Volt 250 bass&ABR, Scanspeak 13M8621Mid & D2905/9300Hi. HD595 cans.[br]2)Quantum Elec based active system self built.

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  • 2 months later...

I got an Amarra 305 working in active mode from the Mio Console (dsp+), I have also had it running Pure Music in Active mode.

 

Both are very good, as a word of caution I had a little trouble running files greater with greater resolution than 44.1kHz 16Bit running through the Mio console.

 

That said, others have not had this problem.

 

I ran a 2.1 system in both, so stereo & mid/bass and mono sub.

 

 

 

Trying to make sense of all the bits...MacMini/Amarra -> WavIO USB to I2S -> DDDAC 1794 NOS DAC -> Active XO ->Bass Amp Avondale NCC200s, Mid/Treble Amp Sugden Masterclass -> My Own Speakers

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