Since the dspNexus 2x8 can be used for either new speaker designs or reworking old speaker designs, decided to give it a try with a pair of Magnepan MG10QR planars I found. Had a pair of Magnepan MGIIB's back in the '80s, so a good place to start. At 10.5in wide about half the width of my old MGIIB's, so that should improve imaging. Mechanically time aligned, but adding a servo sub will time align them for the room setup.
These are the original Quasi-Ribbon model of the speaker, a two way crossover design with single pole filters. The response is reported as 80Hz to 22KHz for the speakers, so a good subwoofer is needed for first octave sound reproduction. I know how to do that!
Speaker measurements are needed to see what will be the new DSP crossover design.
A few surprises along the way, so will see what happens.
Quote from: HAL on June 14, 2023, 05:29:23 AM
Since the dspNexus 2x8 can be used for either new speaker designs or reworking old speaker designs, decided to give it a try with a pair of Magnepan MG10QR planars I found. Had a pair of Magnepan MGIIB's back in the '80s, so a good place to start. At 10.5in wide about half the width of my old MGIIB's, so that should improve imaging. Mechanically time aligned, but adding a servo sub will time align them for the room setup.
These are the original Quasi-Ribbon model of the speaker, a two way crossover design with single pole filters. The response is reported as 80Hz to 22KHz for the speakers, so a good subwoofer is needed for first octave sound reproduction. I know how to do that!
Speaker measurements are needed to see what will be the new DSP crossover design.
A few surprises along the way, so will see what happens.
The only commentary I have is that my GoldenEar Triton Reference speakers use DSP, and they are the best speakers I've ever had. The bass integration with sub and mids is exactly perfect. :thumb:
To me, DSP has completely surpassed the sound quality of passive crossovers when it is a competent design. I will not go back.
Quote from: HAL on June 14, 2023, 10:50:53 AM
To me, DSP has completely surpassed the sound quality of passive crossovers when it is a competent design. I will not go back.
I agree. So please allow me to seek your opinion. Given that you're a friend (done business with?) Greg of GTAW, if I'm not mistaken his design approach is the best crossover is no crossover. Hence I believe his speakers don't use any (or I recall hearing something about a capacitor used for some kind of "protection", not sure though). Can you opine on the benefits (or lack thereof) of no crossover?
As a side, I've heard other (boxed) single driver full range speakers besides Greg's. They sound fine but honestly I cannot hear anything advantageous versus multiple drivers with crossovers.
Thank you. :)
Hal
Greg's planar/ribbon combinations did not use a crossover on the woofer/mid panel, but had a cap on the direct drive ribbons. The new ribbons he said are transformer coupled, so probably also has a cap to remove LF energy from the tweeter ribbon depending on the transformer.
I have heard them play very loud without strain, so his system is robust from the driver material and magnetic field strength components of the design. Every generation of his planars sounded better. He also uses them with a sub array. In the past servo subs, now standard subwoofer designs. Probably for the same reason everyone else is for lack of servo amps from Rythmik Audio.
I prefer using high rate XO's to remove more energy from the woofer and tweeter drivers to let them play loud and clean. I also like using high rate acoustic L-R style crossovers for all the crossover points. I will be doing exactly that with the MG10QR's. No linear phase filter crossovers will ever be used for speakers from HAL.
When you can make a pair of LM10n planars play 180Hz to 20KHz flat and have plenty of acoustical output using a high rate L-R crossover, and sound this good, why bother with other types. The MG10QR's should be a lot of fun since the bass panels go to 80Hz. The servo subs will have a simple job to do.
I am not a fan of boxed full range cone drivers other than for electric guitar and amp use. That is a different animal than for music reproduction.
To drive the MG10QR's bass panels, will be using Pizza Box Amp v2.1 with the new 1kW SMPS and capacitor filter. Those will be tested soon. The QR tweeter amp will be the Orchard Audio Starkrimson monoblocks with 300W GaN SMPS.
This will be 500W into the planar 4 Ohm load, so should have plenty of dynamics even with the 86dB/1w/1m sensitivity to 113dBSPL. The QR's should be good to 108dBSPL.
The fuses will remain after the crossover upgrade.
The dspNexus 2x8 DSP crossover design is done for testing.
Now to mod the speaker crossovers to allow access to the two drivers directly.
Removed the connector panel on the MG10QR and this is the passive crossover and wiring to the drivers. They are fast-on connectors so easy to disconnect the original crossover, remove the original connectors and use 5-way binding posts and new wiring directly to the drivers to biamp the speakers. Will use the Pizza Box Amp v2.1 on the woofer panels and the Starkrimson monoblocks on the Quasi-ribbons.
The EA dspNexus 2x8 will be the DSP crossover to replace the passive crossovers and add the servo subs below the 80Hz rolloff of the woofer panels.
With the nominal crossover will be able to make measurements to see what will improve the response of the system. Using higher order Linkwitz-Reily crossovers will improve power handling for the drivers and the amps.
This is Deja-Vu as I did this to my MGIIB's back in the 1980's, since the capacitors at the time were Mylar and Polypropylene caps were then available. A bit bigger, but sounded a lot better. Now to bypass all the passive components and see what the MG10QR's are fully capable of sounding like.
Quote from: HAL on June 20, 2023, 04:24:30 AM
The EA dspNexus 2x8 will be the DSP crossover to replace the passive crossovers and add the servo subs below the 80Hz rolloff of the woofer panels.
With the nominal crossover will be able to make measurements to see what will improve the response of the system. Using higher order Linkwitz-Reily crossovers will improve power handling for the drivers and the amps.
By using the higher order filters, you can pull that mid/tweet fuse and replace it with a short piece of 1/4" copper tubing. This greatly helps the dynamics of small Maggies.
Dave,
That is a good idea.
I know my old MGIIB's sound better every few years replacing the fuses and cleaning contacts.
Rich
Quote from: HAL on June 20, 2023, 02:06:13 PM
Dave,
That is a good idea.
I know my old MGIIB's sound better every few years replacing the fuses and cleaning contacts.
Rich
Polish up that copper tube first.
Yeah. I'm still me :rofl:
Quote from: HAL on June 20, 2023, 02:06:13 PM
Dave,
That is a good idea.
I know my old MGIIB's sound better every few years replacing the fuses and cleaning contacts.
Rich
Rich, what are you using to clean contacts? I'm attaching a PDF of what is supposedly best, but I cannot order this unless in bulk (i.e. I cannot find it retail).
Thanks.
I use Caig Deoxit for contact cleaning. There is also Deoxit Gold for those contacts. Used it for many years and very happy with it.
One or two cans will probably last me a lifetime for contact cleaning. Easy to find.
Quote from: P.I. on June 20, 2023, 02:49:58 PM
Quote from: HAL on June 20, 2023, 02:06:13 PM
Dave,
That is a good idea.
I know my old MGIIB's sound better every few years replacing the fuses and cleaning contacts.
Rich
Polish up that copper tube first.
Yeah. I'm still me :rofl:
Dave,
I would expect nothing less! :)
Quote from: HAL on June 20, 2023, 04:18:09 PM
Quote from: P.I. on June 20, 2023, 02:49:58 PM
Quote from: HAL on June 20, 2023, 02:06:13 PM
Dave,
That is a good idea.
I know my old MGIIB's sound better every few years replacing the fuses and cleaning contacts.
Rich
Polish up that copper tube first.
Yeah. I'm still me :rofl:
Dave,
I would expect nothing less! :)
https://www.mcmaster.com/products/tubing/general-purpose-copper-tubing/?s=copper+tubing
I've used this for lots of things in different diameters. Good stuff.
General disclaimer: Bypass fuses at your own risk. Be smart. Enjoy the music!
Dave,
Understand.
I will start with the tweeter fuse and see how it goes. Should be easy to see what it can take.
More worried about power off transients if I forget to first turn off the amps. I need a timer startup system like Parasound has in the JC preamp and JC poweramps. The Starkrimson Ultra DIY 250W modules have 12V triggers for power up/down. On the list of things to do. Until then a line strip with a switch. :o
Rainy day so made the two sets of wire connections from the planar fast-ons to the 5-way binding posts.
Hope to have the 5-way binding posts this week to make the swap.
Quote from: HAL on June 20, 2023, 04:17:11 PM
I use Caig Deoxit for contact cleaning. There is also Deoxit Gold for those contacts. Used it for many years and very happy with it.
One or two cans will probably last me a lifetime for contact cleaning. Easy to find.
I've heard and read - both good and bad, mostly good though of deoxit. The only contacts I would be wanting to "clean" are XLR, RCA and speaker connections. Even then my personal belief is this activity is best every 5-10 years or so, not annually or semi-annually. In the case of speaker connections, my main concern is that I use bare wire (Belden 5T00UP) and although hand tight, it is *very* tight as I have rather good dexterity and strength in my fingers. It's so tight that it actually crimps, albeit to a very small degree, the wire. If I take the wire out to spray it and the terminal, I would never be able to reinsert it in the same spot and, therefore, cause yet another crimp. I would consider spraying the terminal and wire while connected, but haven't thought hard enough about it nor do I have the liquid (deoxit or something else).
The 5-way binding posts arrived today. Superior Electric BP30 model in red and black.
Test fit the connections and everything looks good.
Will see if it will all fits in the original crossover cavity.
First set of biamp cables connected to the MG10QR drivers.
Now time to remove the original connectors and install the 5-way binding posts.
The MG10QR's connector plate with the new biamp wiring and 5-way binding posts is ready to install on to the speaker.
Now to shrink tube the original connector wiring and then on to speaker #2.
First MG10QR rewiring for biamp use is complete!
Time to rework speaker #2.
Quote from: HAL on June 30, 2023, 03:59:52 AM
First MG10QR rewiring for biamp use is complete!
Time to rework speaker #2.
Hi Rich,
What brand are the binding posts?
Nick
Nick,
They are Superior Electric BP30 models. I also like the BP30-10 models. They are getting harder to find at decent prices. Got these on Ebay in original packaging.
The MG10QR #2 is modified and ready for testing and listening.
Monday a new pair of Orchard Audio Starkrimson monoblocks with GaN SMPS will be arriving to biamp the speakers. The first pair are the ones I used at LSAF2023 that everyone commented favorably on the system sound quality with the dspNexus 2x8. :)
Quote from: HAL on June 30, 2023, 04:41:41 PM
Nick,
They are Superior Electric BP30 models. I also like the BP30-10 models. They are getting harder to find at decent prices. Got these on Ebay in original packaging.
Thanks, Rich 👍
Nick,
You are most welcome!
The second pair of Orchard Audio Starkrimson Monoblocks GaN Class D amps with the GaN SMPS arrive Monday.
Making 2ft speaker cables for each of them to biamp the MG10QR's to use with the dspNexus 2x8. Will use spade connectors to the 5-way binding posts and tinned wire at the amp end. Have some rosin core 2% silver content eutectic solder for the tinning.
The connections from the dspNexus 2x8 to the monoblocks will be XLR balanced interconnect cables. Will take 15ft cables from the DSP crossover to the monoblocks in the setup. Might even build some if I can find all the parts in storage. :o
The Orchard Audio Starkrimson monoblocks have arrived. This is the newer style chassis than my previous pairs. Connectors are all on one side.
Time to make the 2ft speaker cables from the amps to the MG10/QR speakers 5-way binding posts.
Finished the 2ft speaker cables for the amps to the MG10/QR drivers to get the system setup.
Next is time for some driver frequency response measurements to see what is needed.
Have the first step of the room acoustics materials setup to check out. Side walls have some absorption and rear wall has more diffusion. Room needs more absorption, but a lot better than the reverb chamber it was.
Installed the Magna Risers on the Magnepan MG10/QR speakers. The screws on this pair were 1/4-20 x 1-1/4" style where normally they are 10-32's. Just had to remove some of the coating from the screw holes on the stands to fit the original screws.
Next is to wire them up to the Class D amps and start making some acoustic measurements.
Quote from: HAL on September 18, 2023, 07:07:05 PM
Have the first step of the room acoustics materials setup to check out. Side walls have some absorption and rear wall has more diffusion. Room needs more absorption, but a lot better than the reverb chamber it was.
Installed the Magna Risers on the Magnepan MG10/QR speakers. The screws on this pair were 1/4-20 x 1-1/4" style where normally they are 10-32's. Just had to remove some of the coating from the screw holes on the stands to fit the original screws.
Next is to wire them up to the Class D amps and start making some acoustic measurements.
I recommend raising the " - 16" off of the floor. Get it up to where it will be more effective!
Dave,
I am planning on putting more of the diffusor panels on top of the first 3 rows. Should be 8' high once done.
They are just stacked for the time being. Nothing is being installed until I can get some measurements done with at least REW.
These are the AQD styles. The Mr T's are still in boxes for CAF2023. After the show, the portable acoustic walls will go to the rear wall of the room.
The rest of the room equipment is still in the POD. Hopefully starting Thursday at least the equipment racks will be brought back in to setup the new system.
Have the MG10/QR's wired to the Orchard Audio Starkrimson Monoblocks for testing with the dspNexus 2x8 DSP crossover.
Setting up the Music Server PC with the software for development and testing.
QOBUZ is already on the PC from LSAF2023 and then try the planars without the servo subs.
The Magnepan MG10/QR speakers are now playing music in biamp mode with the EA dspNexus 2x8 DSP crossover driving the four Orchard Audio Starkrimson Monoblocks. Every planar driver with its own HiRez DAC and monoblock amp. 🙂
Now that the system is running will use REW to make measurements with my calibrated Behringer ECM8000 mic to see what needs some crossover work.
After some in room measurements of the MG10/QR speakers, worked on an EA dspNexus 2x8 DSP crossover system to correct what I see as things needed to be addressed in the frequency response.
The time gate is 500mSec, so this includes room reflections at the ECM8000 mic. The mic is at the listening seat on axis.
There is a version of an 80Hz High Pass Filter for use when the 4x8in servo subs are running. That will be tuned once I have final measurements with the servo subs.
The custom modified HX300-8OB servo amps are here and now in their boxes to get wired to the servo subs.
Using the Neutrik 4-pole Speakon connectors on the cabinets and wiring harness for simple connections.
Wiring the cable harness is ongoing as the parts arrived today to complete the wiring.
The 4x8in OB cabinets are to be finished this week and delivered.
Getting closer!
Quote from: HAL on October 21, 2023, 05:00:34 PM
The custom modified HX300-8OB servo amps are here and now in their boxes to get wired to the servo subs.
Using the Neutrik 4-pole Speakon connectors on the cabinets and wiring harness for simple connections.
Wiring the cable harness is ongoing as the parts arrived today to complete the wiring.
The 4x8in OB cabinets are to be finished this week and delivered.
Getting closer!
:thumb:
The servo amp are ready to use with the wiring completed.
Next is the sub cable harnesses. Since these are for shows, the wiring is external to make it easy to assemble and disassemble for movement and setup.
Have the module grill frames, so will try to put the black speaker fabric on them for the show.
Quote from: HAL on October 22, 2023, 05:00:00 AM
The servo amp are ready to use with the wiring completed.
Next is the sub cable harnesses. Since these are for shows, the wiring is external to make it easy to assemble and disassemble for movement and setup.
Have the module grill frames, so will try to put the black speaker fabric on them for the show.
Grill cloth, schmill cloth! Audiophools love to see the drivers dance!
Quote from: P.I. on October 26, 2023, 07:30:02 PM
Quote from: HAL on October 22, 2023, 05:00:00 AM
The servo amp are ready to use with the wiring completed.
Next is the sub cable harnesses. Since these are for shows, the wiring is external to make it easy to assemble and disassemble for movement and setup.
Have the module grill frames, so will try to put the black speaker fabric on them for the show.
Grill cloth, schmill cloth! Audiophools love to see the drivers dance!
Hmmm....to grill or not to grill....that is the question 🤷 😁
Quote from: Nick B on October 26, 2023, 09:13:52 PM
Quote from: P.I. on October 26, 2023, 07:30:02 PM
Quote from: HAL on October 22, 2023, 05:00:00 AM
The servo amp are ready to use with the wiring completed.
Next is the sub cable harnesses. Since these are for shows, the wiring is external to make it easy to assemble and disassemble for movement and setup.
Have the module grill frames, so will try to put the black speaker fabric on them for the show.
Grill cloth, schmill cloth! Audiophools love to see the drivers dance!
Hmmm....to grill or not to grill....that is the question 🤷 😁
No question. As I wrote to you in your subwoofer thread, "I like options". :thumb:
I agree with P.I. that "Audiophools love to see the drivers..." The "dance!" part perhaps, but IMO that depends on
which driver is dancing and how so. I think the movement of any kind would be limited to the bass drivers.
Grills provide advantages that
should include aesthetics as well as protection. Additionally, they
can contribute (or detract) from the sonic attributes. No grill is 100 percent acoustically transparent, but it can be better than 99 percent. In this context, what I mean by "grill" is anything except air directly in front of and closer than one foot to the plane of the driver. A potential positive advantage acoustically comes from increased damping factor and/or taking just enough unwanted airiness away from the top end. I realize this is a slippery slope. Glad I'm not a DIYer or speaker designer. :rofl:
Considering all of the aforementioned, it is my belief/opinion that grills
should be included with any pair of speakers, however, said grill should be
easily (operative word being easily) removable and re-attachable to the frame of the speaker. I'll repeat myself in that "I like options" 8)
The grills are easily removed from each module, so the option is there. Just depends on what the owners would want for asthetics.
All the 8in drivers will face forward, so will be black speaker cones in black modules in the prototypes. Everyone can choose what they want to do for colors for flat pack kits.
The wait continues for getting the cabinets back from finishing.
Looks like painted cabinets will be here Tuesday to install the servo drivers and wiring.
In the mean time, have the two HX300PEQ servo amps and eight servo drivers wired up to test. Looks like everything is working.
Both 4x8in servo sub wiring harnesses are complete and working.
The two 4x8in modular sub cabinets are to be finished and deliverd Tuesday. Then time to install the servo drivers and start measurements and listening.
Today the H-Frame modules were finished and started installing the drivers and wiring.
Stack #1 is complete. Stack #2 is half complete and will be ready tomorrow to test and do some listening.
Quote from: HAL on November 02, 2023, 07:13:55 PM
Today the H-Frame modules were finished and started installing the drivers and wiring.
Stack #1 is complete. Stack #2 is half complete and will be ready tomorrow to test and do some listening.
Lookin' good, Rich 👍👍
Nick,
Thanks! :D
The two OB 4x8in servo sub stacks are complete and making music!
Now for another round of measurements to integrate the MG10/QR's and sub stacks to be ready for CAF2023.
Quote from: HAL on November 03, 2023, 09:39:26 AM
The two OB 4x8in servo sub stacks are complete and making music!
Now for another round of measurements to integrate the MG10/QR's and sub stacks to be ready for CAF2023.
Kewl!!! 👍🏼
Dave,
I had Rythmik Audio modify the HX300PEQ amps to go lower with the H-Frames. I added DSP filters to keep things from hitting xmax.
The higher impedance of the new 8in driver x4 are an easy load for the amps. So far, so good! :D
Quote from: HAL on November 04, 2023, 05:51:42 AM
Dave,
I had Rythmik Audio modify the HX300PEQ amps to go lower with the H-Frames. I added DSP filters to keep things from hitting xmax.
The higher impedance of the new 8in driver x4 are an easy load for the amps. So far, so good! :D
:thumb: