Solen caps in NHT SuperZero make trumpet sound harsh and ear-hurting
- Thread starter Kreshna
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StimpyWan
Addicted Member
The 8.2uF cap should be part of the woofer low pass circuit. Typically, it's a parallel shunt capacitor, tied to ground. Not as audible in circuit as the series caps.
Kreshna
...but I have to know.
I see, thanks.
Trumpets sounded harsh before the recap, trumpets sound even harsher after the recap, but also sounds cleaner. All else being equal.
Yet indeed, the SuperZero A450 has peak at 2 kHz.
I've seen a few posts recently which refer to "sandcast" resistors with disparaging comments. Those so-called sandcast resistors are actually wirewound resistors enclosed in a ceramic casing. Wirewound resistors are good and reliable and generally have better specs than metal film resistors. The ceramic casing helps to dissipate heat and prevents fires if the resistors are abused enough to get that hot. I think they're getting a bad reputation, though unjustified in my opinion, probably because they aren't expensive enough to qualify as "audiophile".
StimpyWan
Addicted Member
Why the negativity concerning sandcast resistors? They've never even been mentioned in this thread. Adding resistors was discussed, though only if one wanted to compensate for the differences in ESR, between NPE and poly.
I did mention replacing sandcast resistors, with Mills resistors, in a different thread. But that was in reference to the other OP stating that he felt his stock resistors, in his speakers, was affecting their sound quality. It turns out, he was confusing resistors and capacitors, is that instance. So, no harm done!
Post #16
StimpyWan
Addicted Member
Ah man, you made me dig for it. I hate work.
Still, I don't read anything "disparaging". Just a comment about a sandcast resistor being in circuit. But, Duelund, Mills and Mundorf do manufacture some nice, aftermarket resistors, if there's interest?
No, not disparaging in this instance, but in the other posts I read recently they seemed to get no love. It just rings alarm bells for me when I see non-technical terms being applied to components along with dismissive comments - I see "internet folklore" being born. "Tropical fish" and "orange drop" capacitors have acquired some kind of mystique in the guitar world for example. I wouldn't like to see forums full of advice for everyone to rip out the "sandcast resistors" from their crossovers because they ruin the sound.
Kinda like sitting in front of the trumpet section?
https://www.bbc.com/news/entertainment-arts-43571144
Congratulations on the high fidelity!
That's what I was thinking.
Trumpets *are* kinda harsh and ear-hurting. I remember being in a large restaurant in Chicago on a Saturday night and they had a band with lots of horns, including trumpets. Without any amplification, it was *loud* and pretty hard on the ears.
I often think about that when people say they want all the volume and dynamics of a live band in their living room. I for one would *not* want the sound of that band in my living room.
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About two weeks ago (September 15, to be exact) I replaced the crossover capacitors of my NHT SuperZero with Solen caps. I noticed the overall sound became less grainy and more fluid, especially cymbals and hi-hats. My wife is not an audiophile, so she doesn't understand audiophile jargons like "grain", but she told me that the sound becomes cleaner.
However, I also noticed that trumpet becomes very harsh and ear-hurting.
I once drove B&W DM302, difficult load speakers, with Sansui A-40, which is underpowered for the job. The sound becomes harsh and ear-hurting due to the distortion. But this time, it is not the same kind of harshness.
First, trumpet is the only instrument that sound harsh. Other instruments like Herbie Mann's flutes and Louis Armstrong's vocals sound nice and lifelike.
And then, while trumpet sounds really harsh and ear-hurting, it also sounds very clean and lifelike. I cannot hear any distortion accompanying the harshness. Trumpet sounds very alive, very real, probably due to the lack of distortion. But it also sounds very harsh that it hurts my ears. Louis Armstrong's songs become heavenly and hellish at the same time. Armstrong's vocals sound really nice, clean, and fluid, but when the trumpet comes then I'm ready to close my ears.
Trumpet also sounded harsh before recap, but not as ear-hurting as now.
I wonder, do capacitors need to break-in? I've been very busy, so I've only listened averagely an hour per day. So the speakers have only been used about 15 hours since recap. Perhaps it would take 100 hours of burn-in until trumpet sounds nice?
Never use Solen caps in the high pass. They are edgy, harsh and bright, which no amount of burn in will help. Never use bypass caps with film/foil caps as they are not needed and will create un-natural artifacts.
This cap works extremely well in the high pass of NHT speakers, https://www.partsconnexion.com/OBLIG-74469.html
I also highly recommend replacing the stock resistors with Mills.
Chip Chester
Super Member
I remember Maynard live in '77, plus before and after. He's the poster child for 'crisp' sound from time to time.
Many interesting things in this thread -- a case of studio-monitor-like accuracy vs. speakers whose sound one prefers. Break-in vs. 'just don't use them'. Plus it's really easy to 'over-record' brass, especially trumpets and trombones. (Studio engineer and trumpet player here.) The fact that it's over-crispy to the OP even on early-technology recordings means the recordings are crisp to begin with, and the new caps may be exaggerating that. Now, back in the day they were recorded, that edginess was needed to make things sound good on the medium-level systems of the day, and it's possible they over-corrected. It's very easy to do, and it's somewhat of a moving target as the decades go by.
But now that the OP has a specific point of comparison, and go/no-go, it will be easier to judge the adjustments made in the future.
Might also be interesting to make back-up room recordings from specific locations to double-check one's sonic memory.
I learned something new AGAIN from NHT superzero crossover , no shunt coil on tweeter = very coherent, with 3 boxes of cap coil resistors ....it sacrifices a little volume for smothness. My improved conclusion was this 3uf grounded with 10watt 22ohm. nice NHT...................oh ya the hash probly is not from the twanger
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Kreshna
...but I have to know.
Come again? You mean I should replace the 4.7 uF cap with 3 uF, then add a 22 ohm resistor in series with the 3 uF cap?
This is what scares me about changing caps. Know poly and film are supposed to be “better”, but always scared to change the character of a speaker. 
Picking up a pair of Mach 3s this week, looks like they use 4 NPEs and 2 poly caps. Need a refoam, but will probably run em as-is afterward if they sound good. Know the caps are “old”, but scared to end up with a situation like this by replacing them.
Joe
Picking up a pair of Mach 3s this week, looks like they use 4 NPEs and 2 poly caps. Need a refoam, but will probably run em as-is afterward if they sound good. Know the caps are “old”, but scared to end up with a situation like this by replacing them.
Joe
You used the word "scare" three times, so perhaps this is an activity you should not be pursuing. However, keep in mind that the idea of changing a speaker's sound can have at least two outcomes: degrade the sound or improve the sound, to name two possibilities. The only way you are going to be able to make this assessment yourself is to try the re-cap and then form your own subjective conclusions. If you read too much of this endless discussion on re-capping, you'll hear dozens of different thoughts. Have some fun with this hobby, reduce the anxiety, and create your own opinions.