The Neutrino - A High-Output Mini-Monitor

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Re: The Neutrino - A High-Output Mini-Monitor

Just a quick post-script:

After a long time of being satisfied with these speakers using a 4-ohm padding resistor prior to the tweeter network, I decided to try a 5-ohm resistor, dropping the tweeter's level just a little bit. This has completely remade and stunningly refined the character of these speakers, and I recommend it wholeheartedly to anyone who wants to try building these (though to my knowledge no one has yet completed a pair, and admittedly they are a 'difficult' build). The result of adding that extra ohm of resistance has been to expand the soundstage even further, in width (enormously), depth, and height, and also to take the edge off the tweeters, which could over-accentuate detail at times and portray some recordings as difficult to listen to. Imaging becomes even a bit more continuous without losing definition.

So, if you are considering building these speakers, use the 5-ohm resistor. If you have a very dead room or find the treble to be less than your liking, then step back to a 4-ohm resistor. I'll put up a new schematic reflecting this change for clarity's sake.

Best Regards,

Rory Buszka

[johnnyrichards]

Re: The Neutrino - A High-Output Mini-Monitor

Thanks for the update, Rory - when I said they were over analytical, I think my limited time with them lead to that impression, and I think it was probably just a hot treble I was hearing. Look forward to hearing the new revision!

[gsswallow]

Port length question:

I'm mid-way through a Neutrino's build, but due to differences in standard sizes in the UK, the port diameters specified in the plans aren't available easily. I have some 30mm pipe left-over from an OS build so would like to use this.

I've modelled this in WinISD but I can't quite get all the metrics to match (ie getting the same port tuning, and box size). It looks like a port with 30mm dia and length of 82mm would be close to identical but I wouldn't mind another pair of eyes on it to confirm before I go any further.

Thanks for your help....

[Wolf]

Remember- larger diameter = longer port. It's a function of tuning, not port volume.
Later,
Wolf

[gsswallow]

Thanks for the tip, Wolf. I also referenced Paul C's Speedsters that use the same driver, but with a different box vol and tuning. I feel I'm close but given I couldn't quite get the 'proper' Neutrino port length, tuning and box vol to match in WinISD, I'm a touch concerned I might have missed something and end up with the wrong length in my change to a 30mm pipe.

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They really are sweet. Keep going and start a new thread with your build pics.

[keith_correa]

Port Resize:
	[Inches]	[cms]
Old Port Diameter:	1.029	2.614
Old Port Length:	4.975	12.637
New Port Diameter:	1.181	3.000
New Port Length:	6.553	16.645

[gsswallow]

Thanks Keith - so bearing in mind there are 2 ports in the original Neutrino plan, and I'm replacing with a single 30mm port, how do I manipulate those lengths to equivalise?!?

[gsswallow]

OK I've had a chance to run this through WinISD again and am starting to make sense of the data. With a box vol of 5.75l (probably a bit high) and tuning at 62 hz, this gives a port length of 16.6cm (matching the above). I only want 1 port, and tuned a bit lower (around 58hz, which takes me to a single port of 8.57cm. I think I'm happy now. I'll start a separate thread with my build tomorrow. Prior warning: I'm no artisan and haven't strayed from the original design much.

[Rory Buszka]

Use caution in tuning the box any differently than my original design (referring to using different modeled Vb and Fb; using a different port(s) to achieve the tuning is open for experimentation). My box design is intended to provide the best combination of bass extension, excursion control, and overall output that is achievable from the W4-1720. Others have used differently sized and tuned enclosure volumes, but these designs (of the other ones I'm aware) were prone to over-excursion of the driver at low frequencies.

[stephenmarklay]

Years later is are the parts to complete this still available?

[Wolf]

Yep!
Wolf