Crossover for Linkwitz LX521

[Tubenstein]

My friend and I are both interested in setup a Linkwitz LX521 speaker system in DSP config.
LX521 Description
http://www.linkwitzlab.com/LX521/LX521-DSP-system-c.jpg

Other than miniDSP 4x10HD, can I use Lake LM-44 for the DSP setup of Linkwitz LX521??
LM 44 | LM SERIES | Lake | Categories | Music Tribe - Lake)
Or do you have a better option for this application?

Thanks!

 

[billshurv]

If you are building an LX521 and buy the official kit plans then you will get access to the OPLUG forum where linkwitz owners hang out. ORION/PLUTO/LX... Users Group • Index page in the meantime a search on there might find the answer. I have no experience of the LM 44 so cannot comment if it can do all the EQ required.

 

[Tubenstein]

Do you think DSP better than ASP for LX521??

 

[billshurv]

That I cannot comment on as I don't have LX521. Properly implemented both should be transparent but DSP allows a lot more flexibility. I will note that, in his last year Linkwitz changed his mind and decided ASP was better after some tweaks and changes. My view is it's as much a belief thing as a technical difference 🙂

 

[Tubenstein]

This is what I thought. If ASP is used, it allows me to have a better quality digital preamplifier such as Cambridge Edge NQ, NAD M12 or Anthem STR Preamp. Otherwise we have to deal with much lower grade DAC built inside the minDSP 4 x 10HD unit.

 

[billshurv]

4x10HD has I2S lines available so you can add your own DACs. nanodigi 2x8 is spdif out as another option. There are choices depending on what you want to do.

 

[Tubenstein]

Really?? So we can use 4 x good quality 2 channel DAC for the purpose??

However, the miniDSP 4 x 10HD only has 2 SPDIF outputs.

 

[billshurv]

for the 4x10 some work inside is required, but all the headers are there to get signals out. The nanodigi is spdif in and out. Music in the Round #93: miniDSP & Ripping SACDs | Stereophile.com has an interesting and heroic comparison of using multiple dacs for surround sound. If your sources are all digital and you have a PC at the centre you could use this approach as well.

 

[Tubenstein]

for the 4x10 some work inside is required, but all the headers are there to get signals out. The nanodigi is spdif in and out. Music in the Round #93: miniDSP & Ripping SACDs | Stereophile.com has an interesting and heroic comparison of using multiple dacs for surround sound. If your sources are all digital and you have a PC at the centre you could use this approach as well.

If you are in our positions, what would you choose?? ASP or DSP??

 

[kevinahcc20]

I have the Linkwitz Orion 3.3.1 with ASP and the LXmini with DSP and I find both to be musically satisfying. Tomato, tomahto.

 

[billshurv]

If you are in our positions, what would you choose?? ASP or DSP??

I cannot answer that for you. 5 years ago I bought a set of ASP boards (not for LX, but because they are useful for all crossovers) as was very much in the pro analog camp. Then I looked at the capabilities of minidsp and the ability to just fire up a change in seconds and so bought one. both methods work so pick the one that suits your budget and preferences.

 

[Tubenstein]

I cannot answer that for you. 5 years ago I bought a set of ASP boards (not for LX, but because they are useful for all crossovers) as was very much in the pro analog camp. Then I looked at the capabilities of minidsp and the ability to just fire up a change in seconds and so bought one. both methods work so pick the one that suits your budget and preferences.

Me, would most likely to use 4 identical amplifier to power sup the LX521, however, my friend planned to use different amplifiers except the two for the midrange (Above 1K and below 1K). As a result, the miniDSP 4x10HD should be a better option as it is able to adjust the gain for each way / drive units, am I correct??

 

[Ugg10]

As a 4 way speaker (LX521 Description) and if you have digital sources then, as described above you could -

Stereo digital signal (Toslink, Coax SPDIF or via a streamer) > Minidsp Nanodigi > 8 channel digital COAX output > 4 x stereo COAX DAC > 4 x Stereo amps > speakers

I have looked into this and am considering the following options -

Input via a Chromecast Audio (note, Nanodigi does not accept USB computer audio streaming)
8 channels of DAC - either Lucid 88192 second hand or 4 x Khadas Tone Board (usb powered)

http://www.symetrix.co/repository/88192_ug.pdf
Review and Measurements of WesionTEK Khadas Tone Board DAC | Audio Science Review (ASR) Forum page 2 for COAX input measurements (even better than USB!)

I have then got two Rotel RMB1066 amps which can be configured as 60w x 6 (4-8ohm) or 150w x 3 (8ohm) through bridging or any combinations in between. But you choice of amp is up to you, if on a budget a RMB1048 give you 8 channel at 50W in one box. Or any combination of stereo amps you are to use.


I am also considering whether to add in a passive variable attenuator in between the DAC and the Power amps (ladder type attenautor) rather than use the digital volume on the source (PC/APP) or nanodigi.


The beauty of this is that it keeps the signal digital until the last minute and you can choose your DAC and power amp combinations.

https://www.minidsp.com/images/documents/Product%20Brief-nanoDIGI%202x8%20Box.pdf

 

[Tubenstein]

As a 4 way speaker (LX521 Description) and if you have digital sources then, as described above you could -

Stereo digital signal (Toslink, Coax SPDIF or via a streamer) > Minidsp Nanodigi > 8 channel digital COAX output > 4 x stereo COAX DAC > 4 x Stereo amps > speakers

I have looked into this and am considering the following options -

Input via a Chromecast Audio (note, Nanodigi does not accept USB computer audio streaming)
8 channels of DAC - either Lucid 88192 second hand or 4 x Khadas Tone Board (usb powered)

http://www.symetrix.co/repository/88192_ug.pdf
Review and Measurements of WesionTEK Khadas Tone Board DAC | Audio Science Review (ASR) Forum page 2 for COAX input measurements (even better than USB!)

I have then got two Rotel RMB1066 amps which can be configured as 60w x 6 (4-8ohm) or 150w x 3 (8ohm) through bridging or any combinations in between. But you choice of amp is up to you, if on a budget a RMB1048 give you 8 channel at 50W in one box. Or any combination of stereo amps you are to use.


I am also considering whether to add in a passive variable attenuator in between the DAC and the Power amps (ladder type attenautor) rather than use the digital volume on the source (PC/APP) or nanodigi.


The beauty of this is that it keeps the signal digital until the last minute and you can choose your DAC and power amp combinations.

https://www.minidsp.com/images/documents/Product%20Brief-nanoDIGI%202x8%20Box.pdf

Well...how can you set the crossover point slope??

 

[Ugg10]

All done in the Minidsp Nanodigi - this allows you to choose cross over points, slopes, add notch/boost/shelf filters and apply delays for each input and output channel.

from the manual -
"Filter types:
oLinkwitz Riley (LR): Available in 12, 24, 48dB/oct
oButterworth (BW): Available in 6, 12, 18, 24, 30, 36, 42, 48dB/oct [/FONT oBessel: Available in 12dB/oct
EQ band selection:
Select one of the 6 x Parametric Equalizers
•Filter type: Select between Peak, Low Shelf, High Shelf "

My aim would be to get acoustically flat using the output filters and then use the input filters to do room correction and to tailor to suit my taste (e.g. 6db 20-20khz slope, BBC 1-3khz dip, bass boost etc.). These can then be chosen (upto 4) using the remote on the fly.

Worth a read of the nanodigi manual - link on here - miniDSP in a BOX : nanoDIGI 2x8 B

 

[sfdoddsy]

If you are in our positions, what would you choose?? ASP or DSP??

I believe the official position from SL was that there was no audible penalty for using the MiniDSP version of the LX521 crossover.

Given how much easier it makes life, that's what I would do.

 

[Tubenstein]

lake processing claimed that we can use 2 x LM44 for the LX521.

However, we are not so sure their equalization capability able to reach the LX521 requirement.

http://www.marketing.labgruppen.com/webservices/dh.ashx?t=qv&v=6315

 

[jeffbook]

So if you spend the $8K for two Lake LM44, you still have to translate the crossover and EQ functions from the miniDSP 4x10 to however the Lake sets these up.

This has been shown on the OPLUG to be cumbersome at best. You would have to match the EQ curves output from the miniDSP. This is best down by measuring the output from the miniDSP and match them by adjusting settings in the new unit. Then confirm that they match the miniDSP on a trial and error basis by repetitive measurements.

Or, you could buy the miniDSP for $545 and either save $7,400+ or spend much more on other equipment. (amps???)

The ASP route may or may not be superior in performance and you lose the ability to adjust settings to dial in the speakers in your room.

 

[john k...]

If you have the configuration file for the 4 x10 HD and the 4x 10 plug-in you can open the config file with the 4x10 plug-in and copy the setting to the plug-in for one of miniDSP's fully digital units as long as the sampling rate is the same. I assume there are some filters that are defined as biquads for the LX521.

 

[Davey]

I answered your friends query on the OPLUG forum. Apparently he wasn't buying it. 🙂 He was asking about a super expensive Accuphase DF-65 crossover unit that has no equalization capabilities. The LX521 requires extensive equalization capabilities on drivers, individually. I told him the Accuphase crossover would not work. How difficult a concept is this to grasp??????

My goodness.
Dave.