Setting up the Nathan 10

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#182
If you measure at 95-100dB SPL I guess that you will capture the data with a comfortable SNR in your place. Only one full spectrum L+R Pink measurement with the mic where your head is when comfortably listening at your preferred position. Full system on, subs, mains, normally used toe in. Use longest time averaging setting on spectrum analyzer. Let it settle for 10secs.
 
#183
markus76 said:
I didn't read your comments about the data - why not?
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Your initial presentation of the results indicated that the nulls are significantly altering the response at angles as narrow as +/- 5°, providing a vertical listening "window" of less than 10°. I cannot reconcile that with the calcs from the driver spacing, and thus repeatedly asked Earl to post the verticals per Geddes.

In response to another's inquiry, you posted a revised version with clarification of the colors, but at a lower +/- 10° resolution which does not resolve the question of how narrow the usable window actually is. It was also unclear whether the second set of curves were a remeasure, or a restatement of the original data.

You said you could hear nulls, but were uncertain as to what they were coming from. Playing pink or white noise, you should be able to ascertain where the nulls are, just by listening to the phase effect.

Earl stated that the nulls were at ~+/- 20°, but observed that there would be interference at narrower angles than that. From my perspective, what we need to know requires better resolution in the region of the axis, perhaps in 2.5° increments out to 10°, and 5° beyond.

I hesitated asking you to do that, since Earl could easily lay this to rest. His reluctance to provide the data may itself be telling, or perhaps it's as simple as his never having measured the verticals, since they are not important to him.

There may also be something stupid going on here, such as a polarity reversal on one of the drivers, something I frequently discover when measuring my own builds. In any case, resolving the matter of the actual and/or intended vertical beamwidth and the amount of tilt, if any, would be essential to prescribing the optimal setup for the system in any listening space.... :yes:
 
#184
The second set of curves were a restatement of the original data.

Even if the optimal vertical listening window is 10° it would be 35 cm for a listening distance of 2 m and 52 cm for 3 m. Is there a problem with that? I never experienced a horizontal sweet spot that big.

Best, Markus
 
#185
salas said:
If you measure at 95-100dB SPL I guess that you will capture the data with a comfortable SNR in your place. Only one full spectrum L+R Pink measurement with the mic where your head is when comfortably listening at your preferred position. Full system on, subs, mains, normally used toe in. Use longest time averaging setting on spectrum analyzer. Let it settle for 10secs.
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Uhmm, gotta position the mic at the exact acoustic center, but that's easily determined watching the RTA and moving it side to side. Where max VHF is max, that's the absolute sweet spot, and it's as narrow as 1/8" or less at those frequencies....
 
#186
markus76 said:
Even if the optimal vertical listening window is 10° it would be 35 cm for a listening distance of 2 m and 52 cm for 3 m. Is there a problem with that? I never experienced a horizontal sweet spot that big.
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We don't know how wide it actually is yet, which is why I suggest better resolution in the axial region.

Also, with the 45° toe-in, if everything is working properly, you will experience a wider horizontal sweet spot than you ever have before. Earl suggests it may be as wide as an entire couch, depending upon a variety of factors.

The link I cited above indicated that, with 4430, the width of a mixing console, perhaps. I'm not sure how wide that was 25 years ago.... 😎
 
#187
markus76 said:
salas, I would love to but the noise in my apartment seems just to be too loud. But I keep at finding a way to measure it...
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Fuzzmeasure's averaging should significantly lower the noise floor, you shouldn't have much problem if you jack up the number of synchronous averaged passes to around 16 and run at a reasonably high level. Even if your room is as loud as a car on the highway, Averaging plus 90db should get you 30-40db out of the noise.

Sean
 
#188
markus76 said:
salas, I would love to but the noise in my apartment seems just to be too loud. But I keep at finding a way to measure it...
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Markus

Our factory in Thailand was right across the street from the airport, planes taking off all day long. We had no trouble with this for the most part. Why would your measurement technique be so sensitive to noise? Is that because its a swept sine with no cross-correlation? That is the problem with that technique.

I use noise and cross-correlation which basically ignores everything external, include 747s taking off. It is not the cleanest technique for frequency response as there is always uncertainty in the data, but its never due to external noise that's for sure.
 
#189
Re: getting power and signal to the subs

col said:
How are people dealing with the issue of getting power and signal to the subs? Iv'e been looking at the increasing amount of cheap 2.4GHz AV Sender/Receiver devices coming on the market.

Do these detract anything from the signal? Would it be possible to just plug one transmitter onto the back of the sub out on the preamp and then have 3 receivers one for each sub (with plate amps)? Would this be better then splitting the signal, having to boost it for 3 connections etc.. And of course not having to run wires everywhere.
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For subs I think this would be fine, full range I'd have my concerns.
 
#195
People frequently apply an adjective to describe the size of the "sweet spot"...so for some speakers it may be just a few inches wide...for others it may be a few feet...toeing in the speakers so the axis (axi? sp?) cross in front of the listener has been a way of increasing the width of it.

How big is your "sweet spot"? 😉
 
#196
soongsc said:
With CD wave guides, the sweet spot will give you a center image that might pretty much shift with the listener.
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Only when cross-fired in front of the listener, which is essential to appreciating how/why it works. There is an optimum angle for generation of the "effect" which correllates with the attenuation provided by the particular waveguide at varying off-axis angles.

Exception: A small group of defined-directivity horns produced by JBL specifically to exploit the principle: Everest I, S2600, and S3100.... :yes:
 
#199
winslow said:
So, have we listened to the speakers yet? I'm curious as to how they sound.
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What?! Acutally listen? Lurking on the sidelines here I have come to the sad conclusion that measurements count for just about everything. How musical and involving a loudspeaker system is of much less importance. I can only hope 'they' will come to their senses and at some point in the near future and start a new thread on how the Nathatn 10's actually sound.
Because.....
🙄
 
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