KeithL
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Post by KeithL on Oct 4, 2022 9:12:08 GMT -5
Errrrr.... kind of... sort of... First of all a speaker driver can often have phase shift due to its mechanical characteristics. (The mass and capacitance of the driver are equivalent to inductance and capacitance.) Secondly many single driver speakers include "passive frequency compensation networks". These may be needed to boost high frequencies... and to suppress in-band resonances which tend to occur in "wideband drivers". These networks are made up of inductors and capacitors and so cause phase shift. It is true that, with a single driver, you tend to avoid sharp discontinuities of the sort you might have with multiple drivers. And, at least with some, you might find a smoother overall phase response. But don't count on "phase coherence". It's also worth noting that ANY single driver is going to be subject to excessive directionality at high frequencies. A driver only has wide dispersion at frequencies where the wavelength is larger than the diameter of the driver... (So, for example, a 6" driver WILL be extremely directional at 5 kHz... and adding something like a grating to improve dispersion makes the phase question more... interesting.) Horns avoid some of this sort of issues... but at the expense of other issues. I wonder how well a single driver / full range speaekr soes in this regard.?? I've seen some Thiel crossovers which were in the region of Square Feet.......Huge and many components..... By definition, a single driver speaker is almost always phase-coherent. There are some exceptions such as "bending driver" speakers whose cones deliberately flex... The Thiel crossovers, despite their many components (which are, for the most part, just notch filters) ARE first-order AND phase-coherent. |
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KeithL
Administrator
Posts: 10,273
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Post by KeithL on Oct 4, 2022 9:33:05 GMT -5
Pretty much... although some very fancy chargers may be able to sense the sort of battery you attach and treat each appropriately. Batteries have also changed over the years... and they've gotten quite complicated. For example, some older technologies had what was called "memory"... If you repeatedly recharged the battery after only half depleting it eventually the battery would "remember" and start "dying" when it was half depleted. (And there were special procedures which were required to get them back to normal.) And some lead-acid batteries are specifically designed for "shallow cycle" (like car batteries)... While some are designed for "deep cycle" (like the batteries used to power the motors on small fishing boats)... And some modern smaller batteries are specifically designed to charge very quickly... But batteries NOT designed that way may overheat, or not charge efficiently, unless you charge them slowly. Basically.... The voltage of lead-acid batteries rises as they charge and starts to rise sharply when they are fully charged - so the charger detects this. With NiCds the voltage stays pretty much the same (you can "trickle charge" them indefinitely and the extra energy is just "burned as heat" - and the battery doesn't mind). But, with some other types, the voltage actually dips very slightly at full charge. This requires a different sort of charger... that shuts off when it senses that dip... And you risk the charger "forgetting that the battery is full", or "being tricked into thinking the battery is full when it isn't" if there is a power fluctuation. (The dip is small - on the order of tens of millivolts with some batteries). Many modern chargers also monitor the TEMPERATURE of the battery as it charges... They may actually limit the charge rate based on how warm the battery is... and charge at the maximum rate where the battery stays at a safe temperature. Or shut off if it gets too warm. Some phone chargers even have a tiny fan that cools the rear of the phone while charging the battery as quickly as possible. (Mine does.) It's also worth noting that, with modern batteries, like lithium ion cells, there are MANY different formulations... So the only really reliable advice is to follow the advice of the battery manufacturer... (They usually offer a data sheet that spells out things like maximum charge rate and what sort of charger to use.) DO NOT assume that they are all interchangeable - even if of the same basic "type". The other thing to be aware of is that some modern batteries can actually catch fire or even explode if charged incorrectly. This is a real thing and actually can happen. (Just look on Youtube for "videos of lithium ion batteries fire" or "lithium batteries exploding".) [Just FYI: www.youtube.com/watch?v=CUgbmCSmSNY ] So if I understand the above, KeithL , there is no such thing as a "universal charger." You have to match the chargers to type of batteries you're charging (and by battery type - not just by battery size). I may be mistaken, but I've read that rechargeable batteries also do best if they're used in the specific charge/discharge range preferred by their technology. Some batteries do best if fully discharged prior to recharging - others do best if maintained between a certain range of charge. I notice that the batteries in my hybrid car, for example, are maintained by the car's charging system in a very narrow charge range. |
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Post by leonski on Oct 4, 2022 18:28:13 GMT -5
I have a SlydeKing flashlight. Tops. But I have a Gen1 version and while it does take an 18650 LIon Cell of 3.7 volts, it has BOTH poles on one end......Not the typical + on the 'north' and
the - on the 'south' end........And it is tough to find. And while you can find such batteries up to 3000mah or more (claimed) this battery is only in 2000mah capacity.
For camping / hiking which may not be best use....it is heavy.....I 'd bring a PAIR of charged cells......and use the dimmer to conserve battery power....Unless I heard a bigfoot stomping around
in the bush outside camp....
If you look at the literature, most or at least many such Lion cells are advertised as 'chipped' which is code for a regulator and overcharge protector.
And If you are curious? Go to one of the RC (remote control) hobby stores and look up appropriate battery chargers. They are $$ if authentic (fakes abound)
but also are VERY smart and will not damage your expensive batteries.
Not to Forget? The 18650 is what put Tesla 'on the map' since his original vehicles took THOUSANDS of 'em for each car.
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Post by leonski on Oct 4, 2022 19:37:42 GMT -5
www.towerhobbies.com/product/rdx2-mini-ac-balance-charger/HRC44299.htmlFirst? this is NOT a cheap-o charger. Lists 4 different Lithium chemistries. NiMh. Nicad AND I'm guessing PB means lead / acid. IOW? You'd be hard pressed to find a battery this one CAN'T charge. Call it 85$ You may see the word 'balance'. This is when a battery consists of multiple CELLS and they must be kept 'together'....... So you don't want them at wildly different states of charge. For example? buddy has a high cpacityy LIon battery.... It is 3 cells and 11.1 volts.
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Post by Boomzilla on Oct 6, 2022 6:14:31 GMT -5
Some files are available only online (YouTube). I'd like to download those files, strip the audio, and turn the audio into saved .wav files. I have DB-Poweramp, thet I think can convert the audio, but I think I need software that can download the actual video without 403 errors. I tried "YouTube Music Downloader" but it only returns 403 errors. Any idea how to actually capture & save YouTube videos (instead of just their URLs)? I'm using a Mac...
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Post by leonski on Oct 6, 2022 14:51:13 GMT -5
I suspect you may be up against the 'Wall Of Copyright'.......
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Post by Boomzilla on Oct 7, 2022 5:40:46 GMT -5
Well... If you're a YouTube premium customer, you can download their videos directly as I understand. Without that membership, I found that iFunia YouTube downloader works (but is painfully slow). My best luck for conversions is still dBPoweramp.
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Post by sockemdog on Oct 7, 2022 8:24:03 GMT -5
Some files are available only online (YouTube). I'd like to download those files, strip the audio, and turn the audio into saved .wav files. I have DB-Poweramp, thet I think can convert the audio, but I think I need software that can download the actual video without 403 errors. I tried "YouTube Music Downloader" but it only returns 403 errors. Any idea how to actually capture & save YouTube videos (instead of just their URLs)? I'm using a Mac... Hey Boom- I've used jDownloader (https://jdownloader.org/home) for many years now. You copy the Youtube URL link and paste into the program and it automatically breaks apart the streams for you to choose what to download. The video stream and audio stream are separate (as well as some other stuff in the package). Then, you can use dBpoweramp (like I do) to convert the music file into whatever format you need.
Good luck! -Brad
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Post by Boomzilla on Oct 7, 2022 16:53:31 GMT -5
Some files are available only online (YouTube). I'd like to download those files, strip the audio, and turn the audio into saved .wav files. I have DB-Poweramp, thet I think can convert the audio, but I think I need software that can download the actual video without 403 errors. I tried "YouTube Music Downloader" but it only returns 403 errors. Any idea how to actually capture & save YouTube videos (instead of just their URLs)? I'm using a Mac... Hey Boom- I've used jDownloader (https://jdownloader.org/home) for many years now. You copy the Youtube URL link and paste into the program and it automatically breaks apart the streams for you to choose what to download. The video stream and audio stream are separate (as well as some other stuff in the package). Then, you can use dBpoweramp (like I do) to convert the music file into whatever format you need. Good luck! -Brad
Thanks much! I'll see if they have a Mac version. A good music editing tool is Wavepad (available for both PC & Mac, unless I'm mistaken). |
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Post by Boomzilla on Oct 9, 2022 10:46:38 GMT -5
Wow, downloading from YouTube is SLOW! But there are some things there you just can't get anywhere else. A lot of bands have videos on YouTube that are unavailable for streaming or CD purchase anywhere. My audio amigo, Russell, has some upscale editing "pro" devices and software that let him tweak even the lossy YouTube video into something that sounds significantly better. He's kind enough to upgrade my downloads for free if I share the files with him. What's the legality of all this? I really don't know. By putting the material on YouTube for public consumption, do the artists forego their copyright claims? Actually, I"d be happy to reimburse the artists for their work were there a method of doing so. But to my knowledge, there isn't unless the artist has the material available on their own website with a purchase mechanism. This seems to be a "no win" all the way around. The consumer is forced to pirate low-quality material from public sites like YouTube, the artist is deprived of the revenue they deserve, and the only winner is the middle man (YouTube) who sells advertising.
Sigh...
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Post by novisnick on Oct 9, 2022 13:54:14 GMT -5
Wow, downloading from YouTube is SLOW! But there are some things there you just can't get anywhere else. A lot of bands have videos on YouTube that are unavailable for streaming or CD purchase anywhere. My audio amigo, Russell, has some upscale editing "pro" devices and software that let him tweak even the lossy YouTube video into something that sounds significantly better. He's kind enough to upgrade my downloads for free if I share the files with him. What's the legality of all this? I really don't know. By putting the material on YouTube for public consumption, do the artists forego their copyright claims? Actually, I"d be happy to reimburse the artists for their work were there a method of doing so. But to my knowledge, there isn't unless the artist has the material available on their own website with a purchase mechanism. This seems to be a "no win" all the way around. The consumer is forced to pirate low-quality material from public sites like YouTube, the artist is deprived of the revenue they deserve, and the only winner is the middle man (YouTube) who sells advertising. Sigh... Many, maybe most YT posts have a link to donate to their channel, but I’ve not fully investigated the topic. Click on the small down arrow below the picture and a link should be there. I’ve often found the link there and have donated. YT may have a copyright or just the creator. I’ve never read the contract as I’m not a creator that’s monetized. |
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Post by leonski on Oct 9, 2022 17:59:31 GMT -5
All decency and civility goes OUT the window when you include the word 'monetized'......
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KeithL
Administrator
Posts: 10,273
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Post by KeithL on Oct 10, 2022 10:02:59 GMT -5
I would suggest you try this one... www.4kdownload.com/-qab5p/video-downloaderIt does both audio and video (video up to and including 8k - and you can set it to automatically get the best resolution available for each video). You can also have it download just the audio directly (although it won't convert it to wav for you). The free version lets you have up to 30 downloads per day. (And, yes, it eliminates the commercials automatically... even without a "Youtube premium" subscription.) They do seem to have a Mac version and they update it quite regularly. Some files are available only online (YouTube). I'd like to download those files, strip the audio, and turn the audio into saved .wav files. I have DB-Poweramp, thet I think can convert the audio, but I think I need software that can download the actual video without 403 errors. I tried "YouTube Music Downloader" but it only returns 403 errors. Any idea how to actually capture & save YouTube videos (instead of just their URLs)? I'm using a Mac... |
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Post by Boomzilla on Oct 12, 2022 10:13:18 GMT -5
Despite "adequate" service from my elderly Mac mini, used as a music server, I think I'm finally ready to move on to a fan-less, head-less NUC running Roon ROCK. I need to buy the NUC without a drive, since I have a variety of SSD drives sitting around idle. I can research the requirements on the Roonlabs website, but wanted to ask if anyone here in the Lounge had gone this route, and had any specific advice for things to avoid or things to add when buying my NUC?
Thanks - Boomzilla
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Post by LuisV on Oct 12, 2022 12:27:25 GMT -5
Despite "adequate" service from my elderly Mac mini, used as a music server, I think I'm finally ready to move on to a fan-less, head-less NUC running Roon ROCK. I need to buy the NUC without a drive, since I have a variety of SSD drives sitting around idle. I can research the requirements on the Roonlabs website, but wanted to ask if anyone here in the Lounge had gone this route, and had any specific advice for things to avoid or things to add when buying my NUC? Thanks - Boomzilla I didn't go down the NUC route, as I ultimately decided to run Core as a docker on my NAS; however, during my research, I came across these fanless cases. If possible, connect your core via ethernet. streacom.com/products/nc2-fanless-nuc-case/hdplex.com/hdplex-h5-fanless-computer-case.htmlwww.akasa.com.tw/update.php?tpl=product/product.list.tpl&type=Fanless%20Chassis&type_sub=Fanless%20NUC |
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Post by brubacca on Oct 14, 2022 7:01:13 GMT -5
Despite "adequate" service from my elderly Mac mini, used as a music server, I think I'm finally ready to move on to a fan-less, head-less NUC running Roon ROCK. I need to buy the NUC without a drive, since I have a variety of SSD drives sitting around idle. I can research the requirements on the Roonlabs website, but wanted to ask if anyone here in the Lounge had gone this route, and had any specific advice for things to avoid or things to add when buying my NUC? Thanks - Boomzilla Boomzilla, I went down this route. Built my Roon Server from a NUC Barebones kit. I'd follow their recommendations for what versions are supported. I got a Nuc Tall so I could use a M2 Drive as the OS and then 2.5" Drive as the storage. My warning would be to first check to make sure the NUC you are buying is on the compatibility page for ROCK. ROCK is not always up to date with the latest NUCs. Second, buy a Samsung M2 Drive. I used the cheap one they recommended and it crashed on me. Samsung SSDs have been good to me. Remember that when you install the data 2.5" Drive that Roon ROCK will erase it. Know you storage requirements. Also realize that the NUC has a max height 2.5" Drive that you can use. Personally I used a m2 SSD and a 2TB Regular 2.5" Drive for my data. Splurge and get the i7 version. Roon can be used to create DSP effect (or room calibration with REW) for a zone. Conceivably you could create a room filter. but you'll need the i7 to do this. After seeing your posts for all these years, I'll bet you'll want to try this. If you know that this is not tempting to you get the i5. Its a great little processor. I built mine around a Nuc8i5.... That is an older version now. I'm always cost conscious (cheap) and bought one from Amazon Refurbished from a company called OEM XS (actually I bought two). Lastly have a BACKUP strategy! You can backup the Library to an external USB drive, but not the DATA. Personally I have a couple NAS drives and use them to backup my music over the network. Some people who have a NAS system load Roon Server on their NAS. I had a bad experience with this, but it was more about my NAS getting hit with Ransomware and losing my music for a few days. If you want to go down the NAS instead of NUC route you need to buy a fairly expensive NAS with a good processor. Also some people buy a NUC SLim and then add a network share for their music, personally I decided to have music local to the server. Lastly you can use an external USB drive as your music storage on the NUC. People like this option because USB3 is fast enough, I just think this looks sloppy, I mean you have this nice tiny server that is the size of 4 CD Cases stacked then these external cable and drive. Good luck. I don't cruise over here often anymore, but I'll check this thread if you want to ask anything else. |
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Post by Boomzilla on Oct 14, 2022 7:42:25 GMT -5
Thanks, brubacca - Exactly what I needed! |
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Post by Boomzilla on Oct 21, 2022 16:51:34 GMT -5
Having digested brubacca’s excellent advice and having visited Roon’s ROCK page to see what’s supported, I think I’m ready. I’d like a NUC10i7fnh with a power supply. I DON’T need: RAM (have a bunch laying around & amigos who can get me anything I lack for free) SSD (I have several on hand in sizes from 500G to 2TB). I’d be ok with a used one, but will buy new if I must. Recommendations? Thanks - Boom |
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Post by leonski on Oct 21, 2022 19:03:15 GMT -5
If you have a mathcin pair of SSD? Might be time for some kind of simple RAID setup?
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Post by Boomzilla on Oct 21, 2022 22:35:24 GMT -5
If you have a mathcin pair of SSD? Might be time for some kind of simple RAID setup? Already got a RAID on standby! |
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I wonder how well a single driver / full range speaekr soes in this regard.??
