Official Luthiers Forum!

As the title suggests, I’m looking for a cheap laptop to use in the shop for things like fft analysis and frequency generation for Chladni testing.

Having spent all my life in the Mac universe however, I don’t know the first thing about “cheap”

What’s a sound card and do I need one? Is Android strictly for mobile devices or is it a computer operating system as well?

Just in case you couldn’t guess, I’m way out of my depth on this one.

Any thoughts/insights/recommendations would be much appreciated.

As always, thanks in advance

Steve

I would recommend getting whatever laptop is in your budget and then getting an external USB mic. You can use the built in mic but I would lean more towards getting an external one. I use a Blue snowball.

Any laptop will have an integrated sound chip and should work fine for what your trying to do. The Realtek chip in most cheap laptops should be fine.

Edited to add: I would get a Windows PC rather than a chrome book or anything running Android. You’ll have a larger set of available applications for what you are trying to achieve.



Sent from my iPhone using Tapatalk Pro

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob

Thanks Brad, much appreciated. Output into an amplifier to drive a speaker for chladni testing?

From the headphone jack?

Steve

Yep, but full disclosure I’ve never done the Chladni pattern stuff, but I don’t believe it will require a high end sound card.


Sent from my iPhone using Tapatalk Pro

_________________
"Is this the one where I trot downfield and act like I'm lost ?" - Billy Bob

You might find apps for your smartphone that will do all you want to do. There are quite a few in the Android O.S. I just picked a couple at random.
https://play.google.com/store/apps/deta ... rumAnalyze
https://play.google.com/store/apps/deta ... om.xyz.fft
https://play.google.com/store/apps/deta ... l&hl=en_US
https://play.google.com/store/search?q= ... zer&c=apps

FWIW, I keep my first Acer Aspire 1 in the shop for frequency analysis, 6/7 years old now.
Use it with a drum mic, picks up lower frequencies well.
I've been using Acers last 3 laptops, they all still work well.

_________________
“There are two men inside the artist, the poet and the craftsman. One is born a poet. One becomes a craftsman.” - Emile Zola

Steve, check out this thread. Whilst you likely won't want to build the whole outfit yourself, it discusses the specifications of the stuff you need and some alternative ways of doing things.

Regarding lap tops, just about any new PC will do what you want, but you will always still need a power amp and speaker for Chladni patterns. 2nd hand PCs will also work fine, but if you are a newby to the MS world, probably best to go with new stuff, as support is always directed toward new systems and away from legacy systems.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

If you are a Mac guy then going to a PC may turn out to be frustrating. Why not just use a MacBook. I have one that I use for all my normal household use and then take it out in the shop when doing frequency testing. Wouldn't have it any other way.

Steve,

You can get a good Macbook Pro from around 2010 for well under $300. They have a good reputation for reliability, and the OS upgrades, if needed, are painless. My shop music system on the old receiver Aux jacks are hooked up to the shop Mac's headphone jack, with an old receiver. I do the Chladni voodoo with a 4" driver from PartsExpress. I looked at all the sound generator app options I could find for Mac and iphones and kept going back to Audiotest for Macs from Katsura because of the ease of changing frequencies by using a scroll wheel mouse, which gives you one-Hz increments without having to ener a new value every time. I use Audacity for FFT, though I don't rely so much on that technique. I think that (with all due respect) Trevor Gore doesn't think too highly of Audacity, but I guess I don't know what it is that I don't know about its shortcomings.

Works for me.

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com

If you buy a newer Windows machine for the shop, you will likely not have it on and operating every day; and if you come from the Mac world, you will be frustrated by the barrage of windows updates that can basically become the machines first priority for the first 10-15 minutes that it is up and running, followed by the frequent reboot that comes with the updates. You're not used to living in the Windows world, where this is considered normal. Barry's suggestion for a used Macbook is a good idea, or look for a cheap solution (tablet?) if that is possible.

Other options:

Use an old Mac machine with a windows emulator (Parallels ??)

Use a Windows PC and once you have the apps you want downloaded don't let it connect to the internet. (Switch off wireless and don't plug in a network cable). That would keep the vast majority of the the annoying stuff at bay without needing to have a lot a Windows experience. I would guess you'd still do all your other work on a Mac.

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

I don't have that sort of problem with my Windows PCs. The downloading and installing of updates can be scheduled for a specific time of day, like during the night. You can also choose to be notified that updates are available but not have them installed until you choose to do so, like before shutting the computer off if you don't want to leave it always on.

_________________
Ignorance more frequently begets confidence than does knowledge - Charles Darwin

I suggest looking into a Chromebook (Android) laptop. But that's new stuff. But zero update and virus/malware problems and no antivirus software to nurse.

_________________
Peter Havriluk

Thank you everyone.

I may have found a solution that will keep me in the Mac ecosystem and not cost me any money. I know, unheard of for macs

But my wife remembered that she had a decommissioned iPad. We pulled it out, I wiped it clean, and while it powers up, I’ve been checking out apps in the Mac App Store.

I’ve already got a good USB mic. A small amp, a speaker, and I may be ready to go.

Without being forced over to the dark side

I’ll keep you up to date, and again, thank you everyone for your help.

Steve

Steve you've probably got all the info you need but I thought I would just add that I use an old stereo amplifier (from the days when we had three or four separate units in the hifi system) which works fine to feed a small speaker.

The other thing is that if you build a little speaker box as I have done (using a cheap 4 inch car speaker) then make sure you have handles on it. You do not want to drop it on your newly fashioned guitar! Or indeed any guitar.

Oh and you will need ear protection. You do have to turn the sound up seriously loud. Chladni patterns are seriously fun. I call them the dancing tealeaves.

Dave

Thanks Dave, and everyone. I’ve got the iPad fired up, I’ve got a 5” speaker ready to be connected, and I’m just waiting for my little amp to show up from Amazon.

Where were these amps when I was spending kajillions in the 70s for audio?

Again, thanks everyone for the help. Once I get everything working, I’ll give an update.

Sorry. _if_ I get everything working.

Don’t want to mess with the audio/guitar gods.

Steve

What amp did you get?

Hey Barry, it’s just a little thing, maybe 4x5”.

https://www.amazon.ca/gp/product/B07BVK ... UTF8&psc=1

But I just hooked it up today. It did a pretty good job of moving a top on a completed box at 314hz, so I’m thinking it shouldn’t have any problems on unattached top plates.

But again, I’m completely new at this. I could be wrong

Steve

Thanks Steve. Looks like a nice amp.

P.S. I already had an old 8” speaker so I used that for my first Chladni pattern efforts. I later found that Al Carruth had written that a small speaker, around 4” dia., worked better by allowing a smaller area, and he was right. Trevor Gore suggests building a small box for the speaker to increase efficiency and that worked well too.

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com

I copied a photo I saw somewhere - I think it was from G&G? - that showed a 4” speaker silicone caulked into the end of a short length of 4” PVC pipe with a cap on the other end. I stuffed a wad of Fiberglas inside. I think I cemented another thickness of pipe around the end so I could sink a couple of screws in as well, to ensure the speaker doesn’t break loose. Works great, powered by a cheap little class D amp with an iPhone app for a signal source (Function Generator Pro - also pretty cheap).

_________________
"We must make our choice. We may have democracy, or we may have wealth concentrated in the hands of a few, but we can't have both." Louis Dembitz Brandeis, Associate Justice of the U.S. Supreme Court