Mini Karlsonator (0.53X) with Dual TC9FDs

[Bearforce One]

Stuffing and Damping for Mini Karlsonator 0.40

Hello gents,

I'm building my first pair of speakers and decided to start with these, in foam core and hot glue. Enjoying it so far!

I'm ordering some foam, felt and stuffing today from QTA Systems, but was wondering how far to go with it. Stuffing in the wedge-type cavity thing, foam on the back, top and bottom panels, and thin felt on the back of the front K aperture, according to Muddjester's nice drawing I'm following.

I also have some Silent Coat adhesive bitumen kicking around.

I'm wondering though, should I put foam on the sides as well? And should I use bitumen matting anywhere? I know from car audio that foam would normally go on top of any matting used. Don't really want to get her all glued up then find I've missed something I shouldn't have.

Grateful for any advice!

Thanks

 

[xrk971]

Damping tips is linked on post 1:
https://www.diyaudio.com/forums/ful...onator-0-53x-dual-tc9fds-296.html#post5577990

 

[Bearforce One]

Lovely, thank you!

 

[twocents]

Bearforce One. Don't overdo the stuffing and damping. The link X shared is great, but applies to wooden enclosures. You are using foam core and it does not require a lot. You mention foam, felt and stuffing

Have a look at these examples:
Mini Karlsonator (0.53X) with Dual TC9FD's

Mini Karlsonator (0.53X) with Dual TC9FD's

Hope it helps.

 

[xrk971]

Thanks for the clarification, Twocents. Yes, foamcore does not require all the extra pads in the front chamber.

 

[soundaddict]

Does anyone know if the wood dampened version sounds as good as the foam board one?

 

[Bearforce One]

Stuffing and Damping for Mini Karlsonator 0.40

Bearforce One. Don't overdo the stuffing and damping. The link X shared is great, but applies to wooden enclosures. You are using foam core and it does not require a lot. You mention foam, felt and stuffing

Have a look at these examples:
Mini Karlsonator (0.53X) with Dual TC9FD's

Mini Karlsonator (0.53X) with Dual TC9FD's

Hope it helps.

Thanks, that's helpful. Reason I asked was I've been following this drawing:

View attachment Karlson Stuffing.doc

 

[Bearforce One]

I was also going to ask, how do you fix the speaker to the foamcore? One of those little clips behind and a screw? I’m guessing you don’t just screw into the foamcore..

Loudspeaker gasket too?

Thanks!

 

[twocents]

I was also going to ask, how do you fix the speaker to the foamcore? One of those little clips behind and a screw? I’m guessing you don’t just screw into the foamcore..

Yes, you can use screws into the foam core, but glue some foam core pieces (or even soft wood pieces) to the back of the baffle for the screws to bite into and more grip. I like to use what is called "drywall screws" - they have a course grain and are black. See X's example:
Mini Karlsonator (0.53X) with Dual TC9FDs

 

[xrk971]

Add some small squares of foam core and stack them a few layers thick. Screw right into to and use drywall screws with lots of thread. Don’t overtighten.

Wood with proper damping sounds as good or better. Bass quality is deeper and more powerful with wood. Less rattling from vibration at higher SPL. But foam properly braced and damped doesn’t rattle either.

 

[Bearforce One]

Lovely gents, thanks for that.

 

[soundaddict]

Add some small squares of foam core and stack them a few layers thick. Screw right into to and use drywall screws with lots of thread. Don’t overtighten.

Wood with proper damping sounds as good or better. Bass quality is deeper and more powerful with wood. Less rattling from vibration at higher SPL. But foam properly braced and damped doesn’t rattle either.

Thank you, sir
For me seems like the wooden/mdf version is the way to go.
Being such a versatile design good for a variety of drivers I prefer to make a solid one which could last for a long time and having only the drivers replaced if they fail.

 

[Bearforce One]

One more thing, how do I decide which amp to use? I’ve never really understood this.. If someone can explain to me in simple terms how and why impedance matters, it would be v helpful..

Drivers arrived today! In the spirit of the forum, I will post some pics when I get chance. But I have small children. Which reminds me - has anyone used or found decent grilles to protect the cones from small fingers?? I’ll be keeping them apart, but it only takes a moment...

 

[Bearforce One]

Just remembered I do have one on my phone..

 

[xrk971]

Great work, Bearforce!

For getting started, I can recommend some low cost but good sounding amps. Do you want ready to run (in a case) or DIY where you add your own power supply, knobs, connectors and case?

Ready to run, or DIY look for a TPA3116 class D amp. Something with built in bluetooth is nice as you can run it from your smart phone wirelessly.

[2020 Upgraded] Bluetooth 5.0 Stereo Audio Amplifier Receiver 2 Channel Class D Mini Hi-Fi Integrated Amp for Home Speakers 50W x 2 TPA3116 - Fosi Audio BT10A Amazon.com: [2020 Upgraded] Bluetooth 5.0 Stereo Audio Amplifier Receiver 2 Channel Class D Mini Hi-Fi Integrated Amp for Home Speakers 50W x 2 TPA3116 - Fosi Audio BT10A: Electronics

DIY:
200W Bluetooth Amplifier Board TPA3116,DAMGOO 100W+100W Audio Amp Board with LC Filter Technique,Dual Channel DC8-24V,Password Free Connect to Phone Quietly Amazon.com: 200W Bluetooth Amplifier Board TPA3116,DAMGOO 100W+100W Audio Amp Board with LC Filter Technique,Dual Channel DC8-24V,Password Free Connect to Phone Quietly: Home Audio & Theater

TDA7297 “Lunch Money Amp”:
TDA7297 15W+15W Digital Amplifier Module, 30W Audio Power 12V DC Mini Stereo Amp Amplify Dual Channel Power Stereo Compatible with DIY Sound Amplify System Component Car Vehicle Auto Computer Speaker Amazon.com: TDA7297 15W+15W Digital Amplifier Module, 30W Audio Power 12V DC Mini Stereo Amp Amplify Dual Channel Power Stereo Compatible with DIY Sound Amplify System Component Car Vehicle Auto Computer Speaker: Home Audio & Theater

I really like this one - it can power just about any speaker for home use and is very quiet regarding background noise and Bluetooth noise. Connects easily and reliably. Well built. $100 but worth it as you will use it for many applications and it sounds great.
Dayton Audio DTA-120BT2 Class D Mini Amplifier 60 WPC with Bluetooth

 

[Bearforce One]

Thank you Xrk, that's very kind. I might even work out how to post a pic the right way up one day...

Re: amps, I probably should have said, I was looking for advice on how to pair an amp with a set of speakers, and hopefully using one of my own amps. I have a small Topping amp, a Fujitsu Eclipse TDA501, also my old Arcam AVR300 that I use for TV. I'm not sure how to decide whether an amp would be too much for a speaker, or not enough iyswim. I've never bothered before to pay any attention to this, but I figure it must be important, as people do tend to..

Having said that... I'm grateful for the list, because I just cannot resist any excuse to buy something new and shiny that may just blow my doors off. Especially if it's cheap and/or the new best thing. I will almost certainly buy at least one more amp at some point, and on the flimsiest of excuses too

And on that note, one more thing (sounding like Columbo here), I did look but haven't seen a mention of how to stop lower frequencies hitting the TC9. It may well be around somewhere, but I'm too green to have noticed. Isn't there some component thing I need to buy and connect up, somehow?

Thanks again for any and all help offered. I've done a reasonable amount of lurking and reading here. As forums go, it does seem pretty chilled out; I've not really seen one argument yet! Which, on the internet, makes a nice change...

 

[Bearforce One]

Yes, you can use screws into the foam core, but glue some foam core pieces (or even soft wood pieces) to the back of the baffle for the screws to bite into and more grip. I like to use what is called "drywall screws" - they have a course grain and are black. See X's example:
Mini Karlsonator (0.53X) with Dual TC9FDs

I have some drywall screws kicking around, so I will use this method, thank you.

I've noticed the TC9 comes with a gasket on the front. I'll see if I can trace an outline of this to replicate it for the back when my gasket tape turns up. The driver fits in nice and snug to the 3" hole. Might chamfer her down a bit from the back before fixing in.

 

[EddieT]

This time I decided to purchase an amp that looks good. My rationale being;

Young folks live on borrowed money,
Old folks live on borrowed time

[

 

[xrk971]

Hi Bearforce,
Any of those amps will be fine - just be careful not to overdrive the speaker with too loud of a volume. Typically a 30w amp won’t have enough power to damage a TC9FD. And even if it does, it’s $10 - and to this day, I have not lost a single TC9 due to over drive - they are quite rugged.

I never bother to limit the low frequencies. If you have a DSP you can do it digitally - limit it to frequencies higher than 40Hz. You can do it as a simple high pass with large bipolar electrolytic cap. There are online filter calculators, for example:

Crossover Calculators

A basic 1st order (-6dB/octave) high pass for 8ohms and 40Hz can be made with two back to back 1000uF electrolytic caps (+ve to +ve connected) and place this in series with the amp and speaker + input. Use a 2.2uF to 4.7uF MKP or equivalent film cap to bypass the electrolytic caps to give better high frequency response. In all practicality, it will sound darn good even without the bypass film cap if you use a quality electrolytic cap Elna Silmic II or Panasonic FC or FM or Nichicon Muse.

 

[spiggs]

What do you think of laying 2 0.4x single TC9FD Karlsonators on their sides against each other for a 24" x 6" speaker in a small cabinet? See my linked thread for what I am building.

Small Record Console Build


X in an earlier post you said they don't sound bad when laid on their side. I think you were referring to the 0.4x size.