 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
68.124.70.13
I've upgraded the capacitors in my crossover. Speakers are Alon Model II. The stock Solen caps have been replaced with Dynamicaps for the tweeter, KimberKaps for the midrange and Sonicaps in the midrange Zobel/shunt. See link below for schematic.
The stock Colber resistors are still in place. They're 3 and 5 watt. I'm interested in replacing two of them that are in the signal path: the 4 ohm going to the tweeter and the 3 ohm going to the midrange. Mills MRA-12 would be an easy choice, but I'd like to experiment with something like Caddock. This may prove to be a meaningless upgrade, but the cost is less than $30.
I've heard good things about Caddock, but which version are people using? Power Film (MS223)? MP-930? Any other brands I should consider?
thanks!
Follow Ups:
Some general comments; I haven't explored past the Mills MRA-12's as they were excellent, so I'll pass on the resistors.
I strongly suggest not messing with the crossover topology. Reversing the mid is a major change, and would require redesigning the xo to get back to a flat response. See, for example, the Dickason Loudspeaker Design Cookbook for good xo design discussion. To reiterate, I agree with the other posters who counsel against making that change.
Wire. I used the Cardas #17 silver. For our project, the silver was warmer and less grainy than copper. (The best Cardas cables use copper and are completely grainless, so I expect I'm missing something.) You could certainly use copper on the woofer, and perhaps the mid. A star wiring configuration, with the star(s) at the input terminals works out well.
Breakin. I am not happy about the breakin phenomenon, but nontheless the bumblebee flies. It really took about 40 hours, depending on the component, before a good evaluation could be made.
After a lot of testing, I just gave up and went to Cardas hardware (Rh plated) across the board. Haven't looked back. In a comparison, Cardas contact cleaner/conditioner was smoother than Craig DeOxit.
Any trials should be conducted with the component soldered in place; we tried clip leads for breadboarding, and that was a disaster.
We found that reducing diffraction was very beneficial. Try some high wool-content soft felt (McMaster has a good selection) on the front panel, and/or rounding the edges of the cabinet with felt or foam or something to see if you'd like to tackle diffraction.
Let us know how it turns out please.
Semper, excellent comments and suggestions. Thank you!
What is a star wiring configuration?
What do you think of Cardas 6/9s copper wire?
I'm not willing to spend the money on silver.
Likely the ones included in the OEM setup :-) Unless they are those square white cast cement Radio shack types. IMO you do have to be Superman to hear any audible differences in Resistors in a passive Crossover.. But no Doubt someone will Bleat otherwise :-)
Did note yr speakers are 3 ways.. Don't go too Nutz on the Improvements.
Caddock is one of the top choice resistors for network. MP 820 is great. However, it has been said that the best resistor for crossover is Duelund.
Thanks Bom! I appreciate the info. Deulund sounds interesting, but is it worth $20 a pop when Caddock MP820's are $7?
From Parts Connexion:
The special charcteristic about this resistor (Deulund) is that it displays a negative temperature coefficient. For example, when the voice coil of a speaker heats up, it's impedance rises. The DUELUND Graphite Resistor counteracts this by means of a decreasing impedance. The results are greatly improved dynamics from the driver.
The special charcteristic about this resistor (Deulund) is that it displays a negative temperature coefficient. For example, when the voice coil of a speaker heats up, it's impedance rises. The DUELUND Graphite Resistor counteracts this by means of a decreasing impedance. The results are greatly improved dynamics from the driver.
How does the heat from the voice coil get transfered to the resistor?
If they share the same current then they both heat at the same time don't they?
inverting the polarity of the midrange driver. Wiring can also stand an upgrade.
Stu
You'll create a dip, perhaps severe, at the crossover point.
The driver is inverted in relation to the other drivers. Actually, instead of a dip, you'll get a reinforcement at the crossover points. Like many three way designs (the Hales had similar issues), the inverted midrange gives a much steeper crossover slope because of the cancellation to the adjacent drivers. However, I find that getting the timing correct is more important than the slight anomalies in the FR, as you don't always have music playing in the reinforcement band width, which is actually smaller than you may suspect.
IIRC correctly, crossover on the woofer is quite high about 400-500HZ since the midrange has no cabinet to lower the response of the driver. At any rate, it is a simply thing to try, merely a wire swap and easily reversed should the user not like it. On the upper models from Alon, the speakers are tri-wired and so inverting polarity is even easier.
I have sold all the Alon models from the 1's through the 5's, and all exhibit mismatched polarities of the drivers, specifically the midrange. I used to demo them and sell them with the mids reversed. Sold quite a few that way, too.
Stu
Hey unclestu52,
"I have sold all the Alon models from the 1's through the 5's, and all exhibit mismatched polarities of the drivers, specifically the midrange. I used to demo them and sell them with the mids reversed. Sold quite a few that way, too."
U have me at a loss concerning this statement. Being a long time owner of both the Alon l's and the Alon Lotus SE mk 11 series of speakers, I have tried reversing the polarity on the Lotus series midrange driver, as it has an external 3 way x-over which easily facilitates this, and found that when I did, there was a huge hole in the midrange spectrum.
Concerning the Alon 1's, unless one physically opens up the speaker cabinet and swaps the midrange drivers polarity by unsoldering the driver leads from the mid/high x-over, reversing them, then resoldering the leads, does one get a true reversal of polarity with regards to the midrange driver.
Just swapping the mid/high polarity on the Alon 1's inputs will put your tweeter out of phase with the woofer and the midrange driver will be out of phase with both of them due to the second order progressive slope of the midrange drivers x-over.
I think Carl did a VERY good job with driver blending in the Alon series of speakers and trying to second guess his vast knowledge of driver blending experience doesn't make sense to me.
With proper attention paid to room acoustics/positioning, both speakers have sounded coherent to this listener :-)
Cheers,
~kenster
with the speakers I get a muddiness in the mids compared to the tweeter and woofer. I get a 'suck out' in the mids in stock form, so my experience is diametrically opposite to yours. You may want to try inverting the entire speaker at the amplifier terminals if you wish to repeat the experiment.
In this case the original poster is contemplating crossover mods and is already in the process of disassembling the speaker, so a speaker wire swap for the 2's would be relatively easily accomplished.
As I say, YMMV.
Stu
Stu, I'll try inverting the polarity of the midrange to see how it sounds. I was planning to pull out the crossovers to put them in an external box so tweaks weren't such a big project. However, I tend to agree with Kenster that Carl knew what he was doing when he designed these things. I don't want to second guess you, but muddiness in my experience (with Alon I and II) has been due to room resonances.
> Wiring can also stand an upgrade.
What wire have you had good experience with? These are usualy pretty inexpensive tweaks that I'm willing to do.
Thanks, Mark
wires are like spicing foods, a little can go a long way, but you need to know what sound change you'd like. So now the question becomes what aspect of the sound would you want to enhance, and the more specific the better.
Stu
Stu, I hate to say, but I'm a skeptic when it comes to using wire to change the overall sound of a speaker. I'm sure it can change things, but I doubt it's as significant as changing caps. I understand silver tends to be bright. I definitely don't want that. I'm looking for something warm, but on the neutral side. People generally recommend large gauge wire for the woofer and small gauge for the mids and tweets. Do you have any specific suggestions?
You'd be surprised. Try the Nordost Two Flat for the mids and highs and the Nordost Flat-line for the woofers. If you're going to leave the crossovers external, these would be good for the internal wiring.
Stu
I recommended trying the midrange driver inverted. YMMV as usual.
I find that doing so does significantly open up the sound of the overall system. I told a friend about this on the East Coast and he had a well known reviewer come over to listen to his pair of 2's in stock form. The reviewer was not very impressed. He reversed the mid driver the next day and had that same reviewer back for another listening session. The reviewer was shocked at the transformation.
Stu
...is to change from inductive to non-inductive which are preferable. However, the inductances we're dealing with in a crossover are vanishingly small, so it's doubtful you'll get an audible change in that department. However, many listeners report a significant reduction in "grain" when moving up to a higher quality resistor. So, if you don't mind spending some cash, this may or may not yield audible benefits. I'd start with the tweeter circuit, then move to the mid range. Listen to each change before moving on to the next one. That way if a problem becomes apparent, you'll know exactly where to look. And one more thing. Ret rid of those 5 watt resistors and replace them with 10 watters.
I'm not expecting a profound change. I know it's going to be subtle. I recently switched to a passive TVC preamp and started hearing new things... I discovered that subtle changes can be revealed. That's what got me thinking about resistors in the crossover. It's a good feeling knowing that your signal isn't filtered through a bunch of transistors, tubes, capacitors and resistors. I like that kind of purity.
> I'd start with the tweeter circuit, then move to the mid range.
> Listen to each change before moving on to the next one.
Excellent idea.
> Ret rid of those 5 watt resistors and replace them with 10 watters.
Can you explain why high watt resistors are better? Are they just an insurance policy in case you overdrive your amp?
All resistors have a degree of noise. Carbon comps are the worst and wire wounds are the best. All things equal a 1 watt carbon comp will be quieter than a 1/4 watt in the same circuit.
I'd go with the Mills. IMHO the caddocks and vishays and such have been served me better in digital circuits rather than analog. But then I admit to a bias as , on paper, a good wire wound is the best resistor.
Russ
Hi.
Theoretically, you're correct on noise levels windwound vs carbon or whatever else.
But we are talking about the final stage of the very strong signal path -
X-network inside the loudspeaker box. Only signal loss or attenuation rather than signal boost as in amp stages.
IMO, it would be a waste of money to invest in a costly exotic resistor of higher than the rated power given very strong signal going through to the speaker units.
c-J
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
