NaO Note II RS

[john k...]

Why do you suggest placing the amps near the speaker? I thought it was preferable to have short interconnects between the minidsp and the amplifiers.

I found a set of affordable second-hand 125ASX2 modules, so my summer project can begin!

Good quality interconnects with short speaker cables will yield the best results.

 

[pkaro]

Good quality interconnects with short speaker cables will yield the best results.

I'm planning on doing this all single-ended, is twisted pair enough for this, or should I be looking at something with single or double braided shielding? Or even something more exotic like triax cables?

 

[Speedskater]

From a theoretical electrical point of view, twisting is better than braiding. But in the real world there won't be any difference.

From a mechanical point of view, twisting may unwind, but braiding won't.

 

[pkaro]

I meant having twisted pair Signal and Ground with an additional braided shield connected to ground.

 

[Juhazi]

I noticed that I needed (braided) shielded interconnects (RCA) between pre-amp/source - minidsp - power amps.

There is a terrible mess of power and signal cables behind my AV-cadget desk, housing a tv, bd-player, dtv-recoder, AV-receiver (works as pre-amp), vintage CD-player, minidsp and two 4-ch amplifiers. And the speaker cables to my 4-ways! It helps to have the power amps next to speakers, but cable between minidsp and amps should be short and straight.

 

[john k...]

I use 3 M commercial, but good quality, shielded, coaxial RCA interconnects from preamo to miniDSP and miniDSP to amps. Nothing home grown. Nothing particularly special.

 

[454Casull]

Coaxial cables with foil and braid shielding are par for the course. You can get a bunch of information from Blue Jeans Cable -- Quality Cables at Reasonable Prices

 

[ultramaroon]

Subwoofers for the Nao Note II RS

Has anyone either bought or made subwoofers to work with the Nao Note 2 RS? About six months ago, I built and love my SLS-based Notes. They're as much speaker as I'll ever need really.. but I'm bored and curious, and use it just enough for home theater that I'd like to see what adding some subwoofers might do. Unfortunately, I don't know anything about integrating subwoofers (I hear good integration is incredibly important)! I don't know anything about anything! As I use them mostly for music, perhaps I should build my own (dipole?) subwoofers? Maybe purchasing self-powered ones are the way to go? Any and all advice appreciated!

 

[john k...]

Has anyone either bought or made subwoofers to work with the Nao Note 2 RS? About six months ago, I built and love my SLS-based Notes. They're as much speaker as I'll ever need really.. but I'm bored and curious, and use it just enough for home theater that I'd like to see what adding some subwoofers might do. Unfortunately, I don't know anything about integrating subwoofers (I hear good integration is incredibly important)! I don't know anything about anything! As I use them mostly for music, perhaps I should build my own (dipole?) subwoofers? Maybe purchasing self-powered ones are the way to go? Any and all advice appreciated!

If you wanted to extend the bass of the Notes below 30-35 Hz I recommend using a pair of monopole subs. At those frequencies it more about moving air than definition. Any variety of commercial, self powered subs, like those available from Parts Express, which have a low pass filter can be used with the Note by adding a high pass filter at the input. I guess I should put up a web page on doing this. Stay tuned.

 

[ultramaroon]

Thanks for chiming in, John. Look forward to whatever you have to say... If you need me to experiment with anything, let me know. Budget isn't a particularly large concern... Just learning and having fun.

 

[SAC]

Any chance you will put up said page John. I too am interested in how I could add subs to make my unfinished Note ii speakers home theatre friendly.

Seperately, I am wondering about the woofer enclosure “access panel”. Can this be omitted or even installed flat rather than angled, more like a table top therefore?

 

[Septimus]

SAC, the plans that John sells includes an alternate (original) design for the dipole bass section that results in a flat top of the back. It actually looks simpler to make than the angled back version.

 

[SAC]

Hi, yes, I do have the alternate plans. I should have realised it does not matter surely, as you point out. I am building those box type enclosures, though modified for my 13" Focal 13v7511 drivers.

 

[pkaro]

Update: So the summer project was put on hold and I actually began work at the beginning of winter.

Good quality interconnects with short speaker cables will yield the best results.

I completed two amps, each consisting of two ICEpower 125ASX2 modules. I used small cases so each amp can sit neatly in the back of each respective speaker so the speaker cables will remain short.

Just to confirm: are both the tweeters and the subwoofers to be connected in parallel to each other with the back facing drivers out of phase?

My planned signal chain will be as follows:

1. Raspberry Pi 3 Model B running Volumio 2 with HifiBerry Digi+ Pro HAT
2. TosLink cable
3. MiniDSP 4x10 HD
4. MonoPrice 10-Feet 22AWG RCA
5. ICEPower 125ASX2 amplifiers
6. Monoprice Nimbus Series 14AWG Speaker Cable
7. Nao Note II RS

For volume control I will just use the digital volume control on the MiniDSP. Does that seem reasonable to you all? Are there any MiniDSP settings such as gain switches which may require special attention?

Many thanks for all your help so far.

Lastly, a couple of photos:

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

 

[Juhazi]

Just a little warning, my experience tells that RCAs from preamp (volume control in my case) to dsp and to power amps are very sensitive to induced hums and other noises. This is because (attenuated) voltage is only some millivolts at normal listening levels!

I use shielded cables and try to keep that distance short, less than 1 meter. Balanced line is better for long distance, but ICE power module doesn't support it. Speaker cable uses higher voltage and has sturdier wires, they are not so sensitive to pick up noise. Power and signal cables should be kept far a way form each other.

My setup
sources -(usb/toslink/rca)- HT-receiver-(rca)-minidsp 4x10hd -(rca)-ICEPower125ASX and 50 modules - 4-way dipole diy speaker

 

[pkaro]

Thanks for the heads up Juhazi.

I'll clean up the wiring inside the amps when I get a chance, I bought the ICEpower modules second-hand and used the included wires, though I might order new sets from Ghentaudio if I run into issues, same goes for the RCA interconnects.

I'm itching to get the first sound out of these puppies this weekend, once I am assured the system works and all my wiring is correct I will begin measuring and tweaking.

 

[pkaro]

The speakers are finished, the amps done and the system works!

Apart from a bit of initial trouble wiring the ICEpower modules (I got the 8-pin connector pin-out backwards), and some speaker hum because of the long interconnects (I got rid of that by cleaning up nearby electronics) it's done!

I'll post some pictures once I finalize the setup.

Next question: measurements & room treatment.

Are there good resources for placing dipole speakers and how to distribute diffusive & absorbing material around the listening space? I've come across this calculator Room Setup Calculators which suggests placing the speakers 100 cm from the sidewalls and 150 cm from the back walls in my living room.

I will begin measurements tonight and see where the Room EQ Wizard takes me.

Thanks to everyone for the help so far!

 

[Juhazi]

pkaro, have you read this? The-Magic-in-2-Channel-Sound

I have dipoles on the long wall, turned almost 45¤ inwards, just like in the graph below. Sidewall nearness is actually not very bad, because of directivity. Distance to front wall must be tested, it affects bass very much, below 3-500Hz. But it can be handled with dsp except the reflection nulls. Rotating the speaker helps at higher frequencies. Abrsorbing backwave is not recommended, it easily kills the dipole magic!

 

[gadut]

this new 12" woofer specifically designed for OB from SBA seems a good candidate for dipole.

SB Acoustics :: 12” SB34NRX75-16

I wish John design nao note with all SBA drivers cheaper for me to build

 

[Juhazi]

^If you are using minidsp or other dsp, driver sensitivitiy and response deviations are no problem! The diameter of each unit and the frame is far more important, to control dispersion.