Edgar
-
Posts
2589 -
Joined
-
Last visited
-
Days Won
1
Content Type
Forums
Events
Gallery
Posts posted by Edgar
-
-
58 minutes ago, RealMarkDeneen said:
... I would guess that today, a young man with $1500 will spend it on a telephone to carry around in his pocket before he would buy a piece of high end audio gear.
Do phones really cost that much nowadays? Wow, do I ever feel like a dinosaur. My last phone cost me $59, and yes it's a smart phone. Does everything I need and a few things I don't. But then, I use it almost exclusively for phone calls and texts, the exceptions being those few new electronic devices that require a smart phone just to set-up.
-
2
-
1
-
-
No mumps?
-
10 hours ago, tigerwoodKhorns said:
Sounds like some mods to me 🥵
Yeah, it's easy to get caught-up in the excitement of experimentation.
-
1 hour ago, noviygera said:
On the OTHER hand, the loading down to 80-85hz would not be happening in the conical section, right?
People have reported success with corner-loading, and even with turning the cabinet around so that the mouth points into the corner, so it's difficult to make any predictions.
-
2
-
-
34 minutes ago, noviygera said:
Has anyone modeled LaScalla 1 in Hornresp?
-
2
-
-
-
I agree wholeheartedly. In addition, I have found that many of the remixes ("remasters" they call them) have no bass whatsoever below about 60 Hz. It's annoying when played over a set of loudspeakers that can reproduce bass down into the twenties.
I'm also starting to notice that many of them are heavy in the right channel, as if somebody hung their winter coat in front of the right monitor during the mixing session.
-
I haven't actually tried this, but from the description it may be worth checking-out for your application. I've had no luck with standard epoxy on plastic.
-
1
-
-
2 minutes ago, Deang said:
Mass roll off at 112Hz. Terrible.
What I noticed is that none of them is a perfect replacement for the genuine K33E.
-
2
-
-
1 hour ago, tigerwoodKhorns said:
I got an ad from Partsexpress the other day where they have K33 replacements for $100 delivered.
Here's the WinISD model of the GRS K33E-4, real Klipsch K33E, Crites CW1526 and CW1526C; all in a 137 liter closed box (which yields Qtc=0.7071 for the Klipsch) and all driven by 2.0 Volts.
-
20 minutes ago, Travis In Austin said:
I found this: https://testbook.com/question-answer/if-a-brass-core-of-an-inductor-is-replaced-by-an-i--5eb0442cf60d5d42e6590554
Scroll down to where it says, "The type of core material:" and read the bolded text.
A brass screw will actually reduce the inductance of an air core inductor.
-
22 minutes ago, Travis In Austin said:
You should consider becoming an expert witness, the lawyers would love information like that.
No disrespect intended, @Travis In Austin, but I had my fill of the legal profession back when I was trying to get my own company off the ground.
-
1 minute ago, mboxler said:
I believe your are correct. My 245uh air coil measures .1 ohm DCR. When I switch to resistance at 1 khz, it is .152 ohms. Placing the nail through the center increases the resistance to .524 ohms.
Likewise, at 10 khz, the resistance increases from 1.75 to 3.59 ohms.
In either case, Q is almost cut in half with the nail, which will flatten the peak.
I love it when science works!
However, make certain that your AC resistance measurements are not also including the inductive reactance magnitude.
-
9 hours ago, Travis In Austin said:
So @edgar, even though the nail go the "target" rise in the impedance (345mH), it doesn't act the same acoustically as a 345uH. I assume this is due to the "side effects" you described in earlier posts like hysteresis and other things going on when you but something magnetic down the center of an air core conductor?
The change is measureable. The specific cause(s) of the change are unknown without more information.
However, magnetic hysteresis consumes energy and dissipates it as heat. That means it acts like a resistance. Resistance in an LC circuit reduces the Q, i.e., flattens-out peaks. It's only conjecture, but it seems to fit.
-
1
-
-
17 minutes ago, Travis In Austin said:
Why don't Bob's curve and Klipschguy's curve look more the same?
One of the curves is measured while the other is simulated using LTSpice.
-
12 minutes ago, Travis In Austin said:
... a milliHenry is 1/1000 or a microHenry right?
No, it's the other way around. A microHenry is 1/1000 of a milliHenry.
-
1
-
-
27 minutes ago, Travis In Austin said:
First, I have been lax in specifying the units with microhenrys (mH) or ultrahenrys (uH).
Just a point of correction:
mH is milliHenry; 1/1,000 Henry.
uH (more correctly µH) is microHenry; 1/1,000,000 (one millionth) Henry.
1 Henry is a really big inductor.
-
2
-
-
22 minutes ago, Travis In Austin said:
In that circuit, forgetting the screw for a second, if you put in a 300 rated air core inductor what would you expect to see in the crossover frequency? A rise, a drop. Any way to predict how much change to expect?
I'm not familiar with the particular circuit in question, so I can only answer in generic terms.
From https://www.calsci.com/audio/X-Overs1a.html:For a first-order crossover, L = R/(2PI*f). Rearranging that, f = R/(2PI*L).
If L is multiplied by 1.1, an increase of 10%, then f will be divided by 1.1, a decrease of 9.09%.On to the next page, https://www.calsci.com/audio/X-Overs1b.html:
For a second-order crossover, L = R/(2PI*f*Q). Rearranging that, f = R/(2PI*L*Q).
Again, if L is increased by 10%, then f will be decreased by 9.09%.It gets more complicated with higher-order crossovers. I don't know what the order is for the crossover in question.
QuoteWhat are the typical tolerances and these kind of conductors? 1% 5% 10% 20?
A quick glance at Parts-Express shows 5% and 1%, priced accordingly.
-
38 minutes ago, Travis In Austin said:
On a serious note, will a multimeter with inductance function properly measure the amount of change (if any) caused by a ferrous screw, non-magnetic stainless, brass, aluminum, nylon, hot glue to base, nylon zip ties or (my favorite) duct tape?
I'm sure that it would, if sufficiently sensitive. I think that someone earlier in this thread measured some significant change, didn't they?
But that's just the inductance change. Other effects include magnetic hysteresis and saturation. And now we're getting into the more exotic stuff with which I have only theoretical experience.
-
4 hours ago, henry4841 said:
It would take someone with extraordinary hearing to tell the difference in a blind test.
Let me start with the disclaimer that I agree with your statement.
That said, here we are on a forum that has seen long discussions about the sonic signatures not only of different capacitor dielectric materials, but of different capacitor manufacturers using the same dielectric materials. In that context, we are now dismissing as "negligible" the measurable distortion, not to mention the change in inductance, resulting from an iron bolt inserted into the magnetic field of an air-core inductor.
I just sit back and grin. We audiophiles are an amusing bunch. And please take this comment in the light-hearted nature with which it was written.
-
3
-
1
-
-
10 hours ago, Travis In Austin said:
@Edgar Greg, does a conductive screw, brass or aluminum also create potential for change in this application?
No, only ferrous (iron-based) or other magnetic materials.
EDIT: Well, there might be potential for some eddy currents in other conductive materials, but I think the current in the coil would have to be unrealistically high.
QuoteDoes the higher inductance measured with the ferrous screw correspond with the 1kHZ change in the crossover that was measured? Does the change match up with what one would expect on paper/XO calculator?
It's hard to say. The cores for iron-core inductors have size, shape, and magnetic properties that are well-characterized before the coil is even wound, so the results are predictable (within tolerances). Just putting an iron bolt of unknown size, orientation, and magnetic properties into the magnetic field will change the inductance in ways that are hard to predict.
Bottom line: It's simply not a good idea, but in certain circumstances one might get away with it.
-
1
-
-
1 hour ago, Klipschguy said:
However, if feeding a Khorn speaker system, the amplifier power it would take to saturate the inductor in the tweeter leg of a AA network…well one would not want to be in the same room! Of course you did say “when the current is high.”
True. Just pointing-out the potential pitfalls of using a ferrous bolt to secure an air-core inductor, in the generic case. In the specific case that you describe, the biggest problem would probably be the change in inductance.
-
2
-
-
13 hours ago, Travis In Austin said:
There is more to the problem than just the change in inductance caused by the ferrous mounting screw. You are effectively changing an air-core inductor into an iron-core inductor. That increases the inductance, but the iron core is subject to hysteresis and saturation when the current through the inductor is high. Hysteresis causes asymmetry in the waveform while saturation causes the inductance to change near the peaks in the waveform; both of those count as distortion. This is the reason that audiophiles prefer air-core inductors.
-
1
-
3
-
-
1 hour ago, henry4841 said:
Worse inflation I have ever seen in my 73 years.
Actually, not even close: https://www.macrotrends.net/countries/USA/united-states/inflation-rate-cpi#:~:text=U.S. inflation rate for 2020,a 0.31% increase from 2017.
-
1
-
Audio Research in Receivership??????
in Lounge
Posted
Actually, no. It's a TracFone. I bought it outright for $59. I average about $7 per month for my usage style -- talk and text only; data are available but I don't use them.