Time for some 8in servo subs to go with the MG10/QR's

[HAL]

To go with the MG10/QR DSP Crossover project, worked with folks to develop a modular 8in Servo Sub OB H-Frame 4x8 stack.  These are for the GR-Research 8in servo subs from the latest design.  These will work below the 80Hz cutoff of the planars down to 30Hz. 

These are the flat packs being test fitted before glue-up and then off to be painted.

Getting them ready for CAF2023.

[Nick B]

Hi Rich,

Danny is selling 8" servo kits now? Are you going to use the same painter? Your last ones looked very good

Nick

[HAL]

Hi Rich,

Danny is selling 8" servo kits now? Are you going to use the same painter? Your last ones looked very good

Nick

Nick,
Danny has 8in servo drivers in stock.  I am planning to take these to my painter and get them finished in Hot Rod Black as before.

Problem is that only the A370PEQ and A370XLR2 servo amps seem to be in stock, not the HX300 or HX400 Class D amps.  Those have been out for a long time.  Not sure if Rythmik has HX480's at this point.  The amp also has to be modified for the different driver.  This is an experiment in alternative ideas.

Danny changed the impedance of this batch so a 4x8 stack should be ~4 Ohms.  An easy load for a Class D amp. 

We shall see what happens.

[Nick B]

Hi Rich,

Danny is selling 8" servo kits now? Are you going to use the same painter? Your last ones looked very good

Nick

Nick,
Danny has 8in servo drivers in stock.  I am planning to take these to my painter and get them finished in Hot Rod Black as before.

Problem is that only the A370PEQ and A370XLR2 servo amps seem to be in stock, not the HX300 or HX400 Class D amps.  Those have been out for a long time.  Not sure if Rythmik has HX480's at this point.  The amp also has to be modified for the different driver.  This is an experiment in alternative ideas.

Danny changed the impedance of this batch so a 4x8 stack should be ~4 Ohms.  An easy load for a Class D amp. 

We shall see what happens.

Lots going on there, Rich. Hope it turns out great. I'm putting hours on my Rythmik L12s. I have a long way to go in figuring out how to integrate them properly. My first pair of subs...ever

[HAL]

Nick,
If you have Room EQ Wizard on a machine and can make room measurements of just each sub and then each sub and speaker, we might be able to help.

Even the little iMM-6s calibrated mic for like $20 works with a computer with a TRRS style 3.5mm headphone jack with powered mic input.  I use it with a TRRS extender cable and download the calibration data with the mic serial number.

I am working customers through using REW with the dspNexus 2x8 and they are getting very good results.

[Nick B]

Nick,
If you have Room EQ Wizard on a machine and can make room measurements of just each sub and then each sub and speaker, we might be able to help.

Even the little iMM-6s calibrated mic for like $20 works with a computer with a TRRS style 3.5mm headphone jack with powered mic input.  I use it with a TRRS extender cable and download the calibration data with the mic serial number.

I am working customers through using REW with the dspNexus 2x8 and they are getting very good results.

Rich,

I have REW on a macbook air laptop and the headphone jack as well. I run Roon on my Mac desktop and it has MUSE dsp. Would I not be complicating things quite a bit by using dsp nexus and wouldn't that need to also run on Windows?

[HAL]

Nick,
Using REW on a machine with a soundcard that will work with a mic and output signal to the system is all that is needed for measurements.  The HAL MS-6 PC does it with the built in soundcard and the TRRS connector for output.  Just an example.  The MAC should work.

I used the dspNexus as an example as it becomes the crossover for a speaker and bass management with multiple PEQ's available.  If ROON is doing that in your system, then just use REW to make the measurements and input the PEQ data it calculates into the filters.

One system I am working on has 5 PEQ's below 300Hz split between the sub and woofers and on the other channel 1 PEQ in the sub channel.  These were calculated with REW after some listening seat measurements.  Pretty classic way to do bass management.  The PEQ's are only on the speaker driver channels that need them. 

[HAL]

Checked out the grill frames that insert into the OB H-Frame module face.

Then glued and clamped the first module to do a test fit of the 8in servo woofer.

Will wire the driver before install as they are a tight fit.  Then use a Neutrik connector in a mount to wire up for use.

[Nick B]

Nick,
Using REW on a machine with a soundcard that will work with a mic and output signal to the system is all that is needed for measurements.  The HAL MS-6 PC does it with the built in soundcard and the TRRS connector for output.  Just an example.  The MAC should work.

I used the dspNexus as an example as it becomes the crossover for a speaker and bass management with multiple PEQ's available.  If ROON is doing that in your system, then just use REW to make the measurements and input the PEQ data it calculates into the filters.

One system I am working on has 5 PEQ's below 300Hz split between the sub and woofers and on the other channel 1 PEQ in the sub channel.  These were calculated with REW after some listening seat measurements.  Pretty classic way to do bass management.  The PEQ's are only on the speaker driver channels that need them.

Ok, Rich. That seems pretty straightforward. I have virtually no experience with DSP and set MUSE at 75Hz and the subs as well. Dave made me inline filters at 75 I believe. But there was an issue with the connectors and he's working on that. So all I've used with these subs is MUSE DSP. I will say that when I set the DSP at 75, it did cause a slight peak at 500 or so. I don't know if that is because the Roon software is not the best or simply because it's common with DSP software.

[HAL]

Nick,
The 500Hz peak is not something common to DSP use as it is not seen in the dspNexus 2x8 in use as the crossover and room correction.

With a little time REW will become a valuable tool in getting the system and room better balanced.  I just got two customers using REW and they are very happy with the results.  Measurements are your friend.

Both those customers have a ROON based system and run Windows 10/11 for the ROON Bridge.

Rich

[Nick B]

Nick,
The 500Hz peak is not something common to DSP use as it is not seen in the dspNexus 2x8 in use as the crossover and room correction.

With a little time REW will become a valuable tool in getting the system and room better balanced.  I just got two customers using REW and they are very happy with the results.  Measurements are your friend.

Both those customers have a ROON based system and run Windows 10/11 for the ROON Bridge.

Rich

I tried to find that mic on Amazon, but didn't see it. Will check the audio sites tomorrow. I attached a link for a pic of the Roon DSP to show that peak. The 12"" drivers are sounding better. It's quite an adjustment (at least for me...) getting used to having subs

https://share.icloud.com/photos/040cwj2YBgY10aqjSGWdH3BrQ

[HAL]

Nick,
There are three mics to look at depending on you PC.  If it has a TRRS connector look at the Dayton Audio iMM-6 and iMM-6S mics:

https://www.parts-express.com/Dayton-Audio-iMM-6-iDevice-Calibrated-Microphone-390-810?quantity=1

https://www.parts-express.com/Dayton-Audio-iMM-6S-iDevice-Calibrated-Microphone-Straight-390-812?quantity=1

If you have a balanced mic input to the measurement system, the eMM-6 is an option:

https://www.parts-express.com/Dayton-Audio-EMM-6-Electret-Measurement-Microphone-390-801?quantity=1

Not sure about Amazon except for the basic Behringer ECM8000 mic without calibration data.  All 3 above have downloadable calibration data from the Dayton Audio website.

[HAL]

Two of the 8in OB H-Frames with the sub drivers installed and wired.

Time for some testing.

[Nick B]

Nick,
There are three mics to look at depending on you PC.  If it has a TRRS connector look at the Dayton Audio iMM-6 and iMM-6S mics:

https://www.parts-express.com/Dayton-Audio-iMM-6-iDevice-Calibrated-Microphone-390-810?quantity=1

https://www.parts-express.com/Dayton-Audio-iMM-6S-iDevice-Calibrated-Microphone-Straight-390-812?quantity=1

If you have a balanced mic input to the measurement system, the eMM-6 is an option:

https://www.parts-express.com/Dayton-Audio-EMM-6-Electret-Measurement-Microphone-390-801?quantity=1

Not sure about Amazon except for the basic Behringer ECM8000 mic without calibration data.  All 3 above have downloadable calibration data from the Dayton Audio website.

Thanks very much, Rich. I'll take a look and see if I can find the specs on my MacBook Air laptop or call Apple. It's a 2013 model.

[HAL]

Finished the 4th sub module and the rest of the wiring for the 8in servo subs.

Once the 4th module glue has set, then install the next two servo woofers and wire them up.