I have a JBL 305P MkII with a dead mainboard and want to restore it using a replacement amplifier.
I’ve already started designing the original 4th-order active crossover, which will go before the amplifier.
The LF and HF drivers are each rated around 41 W.
I’m currently looking at TPA3116D2-based amp boards and trying to figure out if they’re suitable for driving the two drivers.
Would a TPA3116D2 be a good choice, or is there a better amp/module I should consider?

Here's the first post/video that showed the project.

https://www.reddit.com/r/diyaudio/s/LWIR50xvtM

I wasn't able to include audio/music, but here's a video showing the audio quality of the speakers.

I’m restoring a pair of Fostex PM-2 active 2-way monitors. One factory 8-inch woofer has a broken voice coil, and since original Fostex replacement woofers (#379013) are long discontinued, I am fitting a matching pair of aftermarket 8-inch woofers. Have looked everywhere, the only option is hoping for a donor/oem replacement to show up second hand, so in the meantime i have began looking for aftermarket woofers

I’d love some input from anyone with active speaker building/modding, here is an ai overview of the info i have gathered plus the drivers im looking at:

System & Cabinet Specs

• Enclosure Type: Ported / Vented (Dual front-firing ports, tuned to ~40 Hz)
• Measured Internal Dimensions: 22.5 cm × 23 cm × 37 cm
• Internal Volume: ~19.1L gross ~16.5L–17L net (after accounting for active plate amp, ports, and driver displacement)
• Damping: Factory hybrid lining (1" polyfill on walls + light stuffing behind driver cavity)
• Electronics: Bi-amplified active system (120W woofer amp / 40W tweeter amp)
• Electronic Crossover: 2 kHz crossover point
• Cabinet Cutout: 184 mm inner cutout diameter (willing to drill new pilot holes / use T-nuts)
• Use Case: Desktop near-field listening (Dub / DnB / Movies / Casual listening)

Current Shortlisted Drivers

1. Peerless SLS-P830667 (8-ohm, Paper Composite)
   • Specs: 86.5 dB (1W/1m), 11.1 mm extension, 120W RMS.
   • Pros: Heavy excursion capability for low sub-bass; smooth paper cone transition at the 2 kHz crossover.
   • Cons: Lower sensitivity (can compensate via active rear trim knob).
2. Dayton Audio DA215-8 (8-ohm, Aluminum Cone)
   • Specs: 88.0 dB (1W/1m), 5.5 mm extension, 80W RMS.
   • Pros: Stiff cone, fast transient response, tight bass.
   • Cons: Aluminum cone breakup spike around 5.5 kHz (plan to apply a software PEQ notch via Equalizer APO if needed).
3. Dayton Audio DS215-8 (8-ohm, Paper Cone)
   • Specs: Smooth response, 5.5 mm extension, 80W RMS.
   • Pros: Smooth non-fatiguing midrange, no top-end breakup.
4. Budget Alternative: QTX QXW8 (8-ohm, Woven Kevlar)
   • Pros: Very cheap (~£24 each), high power handling.
   • Cons: Limited excursion, punchy upper-bass focus, requires software EQ boost for 40 Hz extension.

Hi,

Recently bought a 12v Bluetooth amplifier. I wanted to put inside a Phillips speaker my dad had lying around, then make it so it plugs into my 12v canopy setup to play music on it while camping.

I wired it all up, music was playing great. I had loose wires connected to a car battery just to test it out before making plugs etc. I then turned up the knob on the amplifier. And turned it down from my phone. So I can turn it up to max from my phone.

Then I started hearing a strange tick in the background happening rhythmically but it would go away once phone disconnected.

Then out of nowhere it just started blasting static noise and now, everyone i power it up, the power up noise starts, then the connection noise starts and stops repeatedly while playing static Im between. And my phone won’t connect to the amplifier at all. All the connections to the amplifier look the exact same as when I soldered it.

Need help Im not very good with this stuff.

Kind regards, Raphael

Hey all! I wanted to get your thoughts about an extended range 2-way desktop speaker.

I've done some reading recently about using small full range drivers in lieu of tweeters on 2-way speakers, and the 2" Tectonic TEBM35C10 seems like a perfect candidate for this. It has extremely wide dispersion to avoid beaming problems typical to these designs.

As the woofer, I'm looking at a W3-2053S. It has an impressively low predicted F3, and is usable up to 600hz.

I'd like to cross it over as low as practical, maybe 400hz, to keep the mids as out of the woofer as possible.

Anyone have any thoughts about this idea?

I'll likely 3D print a ~1.5L box with a sealed portion for the tweeter, and as much passive radiator as I can manage to fit.

No sound going to my Lil 8 inch bass in my truck, recently ran new rca cables, I dont really know what im doing just trying to replicate how my setup was before hand. Any ideas based on the picture?

Edit: Thank you everyone, my uncle was tweaking when he installed this system, ive never seen a proper stereo system before because im poor tbh.

Two-channel valve microphone preamplifier, takes a mic or instrument on a combo XLR/jack, runs it through an input transformer and three valve stages, and puts it back out balanced through an output transformer — into a screw terminal for the main output plus two JST headers that feed an ADAT converter board and a gain meter. I'd like a second set of eyes on it before I order boards.

**Signal flow (per channel):**

Combo XLR/TRS in → P48 phantom feed (2 × 6.8k, switched) → −20 dB pad (820R / 182R / 820R, switched) → polarity reverse switch

→ input transformer (Neutrik nte10-3) → 12AY7 gain stage (68 k plate, bypassed cathode) → coupling cap → 100 k gain trimmer → 12AY7 second stage (150 k plate) → DC-coupled → 12AU7 White cathode follower → output transformer (off-board) → balanced out ×3

The jack tip is normalled through the connector, so with nothing plugged into the 1/4" side the grid sees the mic transformer, and inserting a plug swaps it over to a high-impedance instrument input. Roughly 60 dB of gain in the valve stages on top of whatever the input transformer contributes. The White cathode follower is there specifically so the output transformer gets driven with real current capability rather than a plain follower.

**Power:**
both rails come in from external supplies on screw terminals, nothing rectifies on this board. B+ is 225 V DC regulated, with 2 × 22 µF / 400 V of bulk on-board and a 4.99 k / 10 µF RC per channel for the gain stages. Heaters run on 50.4 V DC with all four valves in series (4 × 12.6 V @ 150 mA); the chain is ordered so both cathode-follower valves sit at the top of the string, which keeps the worst-case heater-to-cathode voltage around 98 V.

**Main components:**

- U1 / U3 — 12AY7 / 6072A, input and second gain stage (one per channel)

- U2 / U4 — 12AU7 / ECC82, White cathode follower output stage

- J1 / J11 — Neutrik NCJ10FI-H, combo XLR + 6.35 mm switching jack input

- SW1 / SW4 — +48 V phantom, Alps SPUJ190900 latching DPDT

- SW2 / SW5 — −20 dB pad, same switch type

- SW3 / SW6 — polarity reverse, same switch type

- R12 / R31 — PT01-B120D-A104, 100 k gain trimmer

- C17 / C18 — 22 µF / 400 V, B+ reservoir

- J4 / J14 and J3 / J13 — input transformer (NTE 10/3), off-board on JST

- J6 / J16 and J5 / J15 — output transformer (UTM3510), off-board on JST

- J8 / J18 — balanced main output, screw terminal

- J10 / J20 and J17 / J23 — balanced output to ADAT converter and to gain meter

- J21 — B+ 225 V in, screw terminal

- J22 — heater 50.4 V in, screw terminal

**Board:**
180 × 200 mm, 2-layer (top signal + ground pour / bottom signal + ground pour), 1.6 mm FR4, 35 µm copper, through-hole only, single-sided assembly. Ground pour on both layers with 161 stitching vias. Custom clearance rules for the high-voltage nets: 1.25 mm for everything at or above ~167 V, per IPC-2221 table 6-1 case B2. DRC is clean — no errors, no unconnected nets.

Any feedback welcome — layout, grounding, the high-voltage side, component choices, anything I've missed.

Once this cures in 24-36 hours I can finally vanish and assemble these beasts!

Bought this cheapo Samsung driver for 10€ in mint condition (for a party sub build) and it ended up getting damaged due to poor packaging.

Should i return it and miss out on the fairly decent price or is there a good way to straighten it out?

None of the surround has peeled off or anything it's just the mounting right that's a little bent. And its a nice even bend too, nothing crumpled or pinched

Hey everyone, I’m planning to build a set of speakers for my dad and could use some input. He only listens to vinyl and mostly listens to Rock, Metal, Jazz and Blues, and lately he’s gotten into Hip Hop too, mainly MF DOOM.

I was thinking about going with Klipsch La Scala clones with the low extension mod or maybe something with Fostex drivers, but honestly I’m open to pretty much anything at this point. Budget isn’t fixed yet so I’ve got some flexibility there.

What would you build for a listener like that? Looking for something that can handle the punch and energy of rock and metal but still sound good and detailed on jazz and blues, and hold up on hip hop bass too. Any recommendations you’d point me toward would be awesome. Thanks in advance!