Hi All,

My first post - pardon any breech of etiquette.

In my past speaker building and studies - I always equated 'order' of a filter to not only the roll-off characteristics 2nd (12dB / oct.) , 3rd (18dB /oct.) - etc; but with the number of reactive elements in the circuit.

For example, a 3rd order circuit in a crossover has 3 reactive elements (e.g. 3rd order low pass (to me) equals series inductor (LF pass) - shunt capacitance (HF shunt) and another inductor (LF pass) 18dB / oct.

In the acoustic analog - air mass would be analogous to electrical inductance and air compression (springiness or compliance) would be analogous to capacitance. So it would stand to reason that a 4th order box would involve 4 reactive elements (roughly speaking). So does anyone know what these elements are? I realize it's a sealed enclosure firing into a vented chamber (I think). And, a sealed enclosure rolls of at 12dB / octave (indicating second order) - how is the vented section modeled? I clearly have much to learn and appreciate reading the collective wisdom here. Also, there is a very old book that drills into these analogies by Harry F. Olsen - "Solutions to Engineering Problems using Dynamical Analogies. This treats electrical, mechanical and acoustical relationships. Headache producing, gnarly math - but interesting concepts.

Interested in your thoughts and experiences.

Good evening,

I'm looking to install a helmet speaker for my Mandalorian helmet. Many people usually use a belt mounted speaker like tour guides do but I'd really like the audio to come from my helmet. I disassembled an old Kindle Fire I had lying around to obtain the speaker unit as that is compact enough for what I need and should be loud enough, but so far that's all I have.

As a minimum, I'm imagining the Speaker mounted onto my sun visor externally, and hen wired into the helmet with an internal microphone. I'd need a power supply which would probably be a USB powerbank, but I'd imagine I'd need some sort of power regulation which I have no experience with.
As an ideal, I'd love sound effects also - 501st Stormtroopers have a static burst effect that activates when they speak but I think that would almost certainly involve some circuit boards to include that?

What I'm essentially asking, is how to wire the Kindle Fire speakers into a Microphone and Power Supply to work correctly, and if possible how to make it do a static burst or even voice changer effect.

Many thanks in advance!

Is this an insane person thing to do? Or is it so crazy it's genius?

Can anyone recommend a simple circuit to basically turn on a negative voltage (-28v) using a 3.3V gpio pin?

I’m using a lm3866 chip amp and I want to control the mute circuit using a microcontroller. Basically the mute circuit needs to sink 0.5ma of current from the chip to disable mute. This is usually accomplished by connecting the negative supply through a resistor to the pin. But I’d like for this to be controlled with an mcu.

If this was a positive voltage I’d have no issue, but not sure how to do it as a negative voltage or current sink. Thanks.

Man, all I want to do is hook up a subwoofer to my TV. I have the subwoofer. Why is it so complicated?

I can’t just wire the subwoofer to the AVR because the subwoofer has speaker wire for output but the AVR has RCA input for a subwoofer.

Can I just get an adapter? Apparently no! I need to spend several hundred dollars on an amp to make it work.

Once I have an amp (which is a whole thing, finding one that will work), my job is done, right?

No way! The wiring on the amps is all different too and there’s no guarantee it will work. Many don’t even come with an electrical cord to plug them into the wall and you have to buy that separately!

I’m not stupid. I have an advanced degree. But I wasn’t expecting I’d have to take night classes to understand amperage and voltage and resistance and wattage and impedance to be able to connect a subwoofer. How do normal people do this? Do they have to hire someone?

Sorry, I guess this is the exact opposite crowd for whom this rant should be intended, but I don’t like feeling stupid!

Hi everyone. I have two large, old speakers. Unfortunately, they don't show the power, so I don't know what it is. They are two speakers, about 80cm x 60cm x 60cm. They have a positive and negative cable input. I'd like to build something that can play music in my house with Bluetooth, nothing too fancy. Basically, I want to do the minimum so that these speakers can play music. Thank you very much for your help and I'll keep you posted on my progress.

Hey, does anyone decent diy stereo speaker kit/build plan in 1000 eur range?

Hi all, as i want to build me a pair of the Ojas Artbook Speakers is started searching for the JBL 328c Speakers, but i can't find any of them available in the EU. Maybe someone has an idea where to find them, shipping to Germany, without any further taxes?

My amp started to smoke the mosfets were burned I changed them but its still shorting help!

I have two main speakers connected to my amp, and I’m looking for a subwoofer to handle frequencies below 80 Hz. My question is what should I look for in a subwoofer? I understand it should have a low-pass filter, but how will the crossover between the speakers and subwoofer work? Will I need to adjust my amp for that? I’ve also noticed some subs with speaker-level inputs, but I’m unsure if those are worthwhile

Which speakers do you recommend on this one

https://preview.redd.it/ga67m9iqk74e1.png?width=386&format=png&auto=webp&s=b5e665054ef4c62fee3fb94637a0944931a1d6e4

I though it would be fun to build a great sounding, but reasonably priced, class A amp for my headphones. I want it to be quality enough to use as my daily driver. I've been soldering and repairing electronics over the years, so I'm not totally a novice. I do have all the equipment (multi-meter, oscilloscope, iron etc) Any advice on a good place to start for plans or kits, point to point or PCB? I don't have the education do design my own amplifier... yet ;)

I’ll try to be brief. I’ve got a 300w passive Sony subwoofer (1.5 ohms). I need an amp in order to connect it to my AVR.

However, everything tells me I need to match the wattage and ohms. Firstly, I can’t find any amps that match.

Second and more importantly, this is for a home theater setup in a pretty small shed. I feel like I probably don’t need anywhere near the 300w the subwoofer provides.

That being said, should I look for a 1.5 ohm amp with a much smaller wattage?

Thanks, and sorry if this is very dumb

Okay folks, after running some designs through WinISD, I decided to go with a dual 15" sub bank for the in ceiling mount. Here is the design showing the view looking up at it and the internals with bracing. This is designed to sit between two 4x12 ceiling beams. The box is designed to that there is a slight gap between the box and the ceiling and beams so some isolation can be used. Drivers will be SQL 15 Series 2 from Stereo Integrity.

A few questions:

- Does the bracing look adequate?
- If I am allowing 1/2" spacing, is that enough for isolation?
- How would you secure this to the ceiling/beams? Some type of brackets with isolation rubber grommets?The ceiling is car decking so has plenty of strength.
- Would you design a cover for the drivers or leave showing?

https://preview.redd.it/t1qlmmlgl44e1.png?width=1270&format=png&auto=webp&s=1b5b2531f62e4b769959bf5359e68a2178f51711

https://preview.redd.it/g6oev1ehl44e1.png?width=1017&format=png&auto=webp&s=583cbe8da413e3c739039ff597079190cd270560

It's a little rough as I designed it in Fusion 360 and I'm just starting to learn how to use it.

Guys I bought a replacement 8 inch subwoofer speaker for my current sub which is a Yamaha YST-215 and it is rated at 5ohms but the subwoofer I bought is of 4 ohms.

Am I good or cooked?

He folks, I picked up this tube preamp a few years ago, but don’t have a lot of use for it now. I’ve been wanting to get a tube phono stage, and was wondering if I could add riaa to something like this to make it a phono pre? While I know that “anything is possible”, is something like this practical and doable for a novice? Cheers

im looking to make a portable " sub" for an rc car with some 1 inch full range drivers and the kab 215 v2. would a small 3 or 4s lipo battery work to power this ? id run an in line volt meter so i dont go too low. i dont want to use 18650s and have another charging device. when i have lipos or life batteries. ive never used lipos for anything other than rcs and even less so with the protek life batteries . but i do know how to charge store and keep an eye on voltages safely. its gonna be a heavy rc car so this wont always be in the trunk.

I have a Pioneer sx636 that one day just sounded terrible.

Static and just generally something not right.

I bought a kit on eBay to do capacitors and other odds and ends

But realize I have never done soldering or anything like this.

What is a good starter project to learn how this stuff works?

https://preview.redd.it/2lm5e77rzx3e1.png?width=3024&format=png&auto=webp&s=bb4bd525b8a72acc62170f9af6cd870b2363df7c

I recently acquired an Onkyo HT-S9100THX speaker set (7 speakers + 1 sub) and one of the midrange drivers on one of the front speakers seems to be blown. It works, but has lower volume output than any other front driver and also crackles or flutters at certain frequencies (Bottom driver in the attached picture).

Here’s the specifications of this speaker:
SKF-960F
Type: Two-way, front
Tweeter (size in inches, type): 1, soft dome
Woofer (size in inches, type): 5, A-OMF cone (2)
Nominal Impedance (ohms): 8
Recommended Amp Power (watts): 130 max
Available Finishes: Black
Dimensions (W x H x D, inches): 6.25 x 17.06 x 7.81
Weight (pounds): 11.7

Would a driver such as the Dayton Audio DSA135-8 (Aluminum Cone) or DS-135-8 (Paper Cone) serve as a good drop in replacement for this driver? I'm assuming I would need to change at least 2 drivers (one each on front left and right to keep it balanced). Or would I be better off getting different Onkyo THX Midrange drivers from ebay (they're not the same model, but same size and bolt pattern).

Or finally, is none of this actually worth it and should I just get a new set of fronts?

Finally got them finished today, still a little tidying up left to do. Initial impressions are extremely good, imaging and detail are spot on.

https://preview.redd.it/dw3uv26qsx3e1.jpg?width=4080&format=pjpg&auto=webp&s=c2b5a6e8fb8fa8f7299c0eb0fb3d28c0b5fa2de3

One of the things that I love about the open baffle aesthetic is the rear mounted driver. It looks so clean, and allows the front baffle to make a statement of its own. Why don’t more cabinet speakers opt for rear mounted drivers with a removable back panel? It seems like it would give you the ability to manipulate the internal damping material as well. Mostly concern for a good seal?