AudioCircle
Industry Circles => Hollis Audio Labs => Topic started by: HAL on 9 Apr 2024, 03:33 pm
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Here is a video tech talk by Tom Martin of The Absolute Sound and The Audio Belle about the Magnepan 1.7i open architecture speaker project.
The Danville Signal dspNexus 2x8 with the AK4499EX DAC's, the Hollis Audio Labs built pair of 4x8in servo sub arrays used with the modified Magnepan 1.7i's were the system described and shown in the video.
The system without the servo subs will be at AXPONA 2024 in the Danville Signal room 356 for an AB comparison of passive and DSP crossovers. Please stop by for a listen at the show.
https://youtu.be/G2aRzygAOgI
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It's a shame they didn't give you credit in the TAS video.
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It's a shame they didn't give you credit in the TAS video.
They stole it. Normal
charles
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There are some inaccuracies in the video.
Danville Signal makes the dspNexus 2x8 system, I helped with the Magnepan 1.7i DSP crossover design from measurements. Danville moded those speakers with connectors to use with the tri-amp system.
The GR-Research 8in servo sub drivers and Rythmik Audio A370XLR3 servo amps were in the OB sub system. The 4x8in modular cabinets are flat pack kits that I built and had painted. Same pair as at CAF 2023. These 4x8in are a prototype OB servo sub system for demos.
Just for reference what I have is a pair of the original Magnepan 1.7's that I modified to use with my dspNexus 2x8 and Orchard Audio Monoblocks. Mine are setup with a pair of 2x12 OB servo subs for trials. This helped in the development of the DSP crossover design.
To me, the bigger outcome of the video is that there are times when technology has come to a point in developement where it can be on par or surpass what is accepted as the standard. I think this will be a very eye and ear opening AB demo of the Magnepan 1.7i's at AXPONA 2024.
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One other thing.
The amplifiers used can be any 3 stereo amps or 6 monoblocks with enough power output to drive the modified 1.7i's. The user can optimize the amps for each driver in the speaker and adjust for the voltage gain differences. You have much lower bandwidth requirements with a tri-amp system, so that helps not having to purchase very large amps. The bass panels could have a Class D amps, tubes amps on the mids and Class A SS on the highs as an example. That is why the dspNexus 2x8 is balanced line level output.
Danville has balanced input demo amps, so is using those for the passive vs DSP AB comparison system for AXPONA 2024.
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I was very impressed with the system at last year's LSAF. Is this version that you were talking about coming down the pike?
Have fun at Axpona.
Mike
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Mike,
I showed a pair of Magnepan MG10/QR's modified for bi-amping with the two 4x8in servo subs towers with dspNexus 2x8 DSP crossover at CAF2023. I removed the passive crossover like the 1.7i's.
I also have a pair of used 1.7's that I have been working with as a baseline. This pair has one super tweeter open circuit, so I just use them as a two way. I have the repair kit for the one 1.7 with the open super tweeter when the weather is warm enough as it has to be done outside.
The system for AXPONA 2024 is the next generation of the ideas with Magnepan possibly offering an open architecture version of the 1.7i's without an internal crossover and three sets of terminals for the planar drivers for direct connection with an external crossover. The early MG!!!A's were like this in the past with an external box for the system and other models. All depends on the response at the show. The video I posted from TAS has generated interest at the show.
The dspNexus 2x8 system at AXPONA 2024 has the latest flagship AKM AK4499EX DAC's for all channels, similar to what I had at LSAF 2023 for the two way system, but an updated board for AKM's latest version of the DAC.
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I set through a demo of the system at AXPONA on Saturday.
Al from Danville did an AB comparison with multiple tracks, for me the starkest difference was heard on the Take 5 by Dave Brubeck.
(https://snipboard.io/gjqXzo.jpg)
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Leo,
Thanks for giving the AB demo a try! :D
I really hope that Magnepan undertakes the open architecture versions of the Magneplanars, as DSP crossovers and correct EQ really make a significant difference in their sound for the better. Then integrating subs can be done well as can room correction where it is needed.
First time I tried upgrading a pair of MGIIB's was in the early '80s with better paaisve crossover components. They really needed new crossovers and EQ even with biamping them with an external line level high pass crossover XO-1 box they sold to add subs. Now that would all be a piece of cake to accomplish with the dspNexus.
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A wrap-up from The Absolute Sound about AXPONA 2024. Danville Signal discussion starts at 10:10 into the video:
https://www.youtube.com/watch?v=c1s12SK__j0
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They stole it. Normal
charles
Who stole what?
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Rich has been involved with the dspNexus since its inception. This is discussed in an article I wrote for AudioXpress a few years ago during development.
Rich was also involved in the crossover design of the 1.7i used at Axpona and also at Tom Martin's home. He was on a video call at the Audio Belle during the same road trip.
Cynthia (Audio Belle) contributed to the videos.
I often mention Rich in conversations with prospects and at shows, etc. He has been invaluable in the process of making the dspNexus a good product.
Al
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For reference, here is the article in AudioXpress that Al is referring to about the genesis of the dspNexus system:
https://audioxpress.com/article/r-d-stories-a-dsp-audio-processor-at-the-heart