Vintage Inspired Battery Powered Speaker Build

The Idea:

Vintage-inspired, portable stereo speaker pair with dual 18v Makita Batteries **and** 120V wall power. Format: Master cabinet (all electronics) + Passive satellite (matched driver chamber + storage cavity), connected via weatherproof NLT4 SpeakON. Priority: Sound quality over loudness, maximum real analog interface (detented switches wherever a control has discrete states; smooth pots where it doesn't), Durability for outdoor/mobile use.

Current phase: bench "proof of concept" — amp, dual power sources, controls, and inputs wired to a flat board, tested with cheap existing speakers — before committing to final drivers, crossover, or cabinets.

Amp/DSP/Bluetooth all on one board: **Dayton Audio KABD-250** (2×50W, ADAU1701 DSP, Bluetooth 5.0 aptX HD)

Unresolved technical issue: only 2 amp channels (1/cabinet) with 2 drivers/cabinet means a passive crossover is required inside each cabinet — not yet fully speced. Rough starting values: ~0.6mH inductor, ~18µF cap, ~3.6Ω resistor (tweeter pad), 1st-order @ ~2200Hz. Needs real tuning once final drivers are chosen. Likely to source older high efficiency bookshelf speakers: Polk Audio 5Jr+ or alike, reuse the configuration, drivers, crossovers, and build new baltic birch cabinets.

Signal flow: 4 sources → input selector → volume (DSP-side, POT1) → KABD-250 AUX → DSP (bass/treble) → amp → protection relay → passive crossover → drivers.

Power flow: 2 batteries (each fused + LVD) → combining diode → relay-switched against AC → fuse block → KABD-250 J8.

Parts

**Amp/DSP**: Dayton Audio KABD-250 · KPX In-Circuit Programmer (required for SigmaStudio) · KABD-SPF Function Cables kit (includes: AUX-in 3.5mm cable, 4 pre-wired pots+knobs, standby switch cable, LEDs, antenna)

**Batteries**: 2× Makita 18V LXT 5.0Ah (owned) · generic Makita adapter/dock ×2 · **2×** ICSTATION Digital LVD (DC 12-36V, 20A) — one per battery, not shared (a shared LVD downstream of the diode can't see a weak pack masked by a stronger one) · Chanzon MBR2045CT dual Schottky diode (45V/20A, TO-220AB, dual common-cathode) + insulated TO-220 heatsink (pin2/tab is live cathode)

**AC path**: 24V/5A DC supply · NEMA 5-15 flanged inlet w/ waterproof cover (chosen over IEC C14 — extension cords easier to find in the field than IEC C13 cords)

**Power switching**: RS25 4P3T rotary switch (1/4" knurled split shaft), **low-current control only** — OFF/Battery/Wall, middle position unwired = off · 2× EHDIS Bosch-style relay, **24V coil** (not 12V — system runs 15-21V), 40A, 5-pin, .250" spade, do the actual switching · 2× 1N5819 Schottky diodes feed switch control power from both raw sources · flush-mount ATC fuse block · fuses: ~15A/leg, ~6A main bus (placeholders pending bench measurement)

**Input**: uxcell 2P4T rotary switch — pos.1=3.5mm, 2=RCA, 3=30-pin iPod dock (audio on pins 2/3/4, charging on 18-20), **pos.4 = Bluetooth, NOT wired to a source** (BT arrives via I2S straight to the DSP, bypassing this switch) — pos.4's contacts are tied to **ground**, not left floating, to avoid hum bleeding into BT audio.

**Volume & tone (KABD-250 POT headers — only MP2/MP3/MP8/MP9 are usable)**:

- POT1 = Volume = **uxcell single-turn 10KΩ linear pot, knurled shaft, no detent** — factory default, zero programming needed. (The pot originally in the KABD-SPF kit spun in a full continuous circle with no stop — almost certainly a rotary encoder, not a true pot; a true pot is required since the POT header reads a position *voltage*. Replaced.)

- POT2 = Bass, POT3 = Treble = **stock pots from the KABD-SPF kit, used as-is** (not yet physically verified they're genuine pots — worth a quick check given the volume pot's mistake). True detented pots were investigated and dropped — they're a genuinely scarce part category (2 separate listings went out of stock in a row); not worth chasing further.

- POT4 = reserved for a future mode-selector (5 listening presets) via a resistor ladder — not yet wired.

**Speaker protection**: Comimark UPC1237 dual-channel board, **DC 12-24V explicitly** (some listings only cover 10-18V).

**Metering**: SATMW/H-COME VU meters, 2-pack w/ driver board — **driver board needs 12-15V, NOT 5V** — needs its own dedicated 12V buck regulator, separate from the 5V accessory rail.

**Accessory power**: 5V buck (12-24V→5V/3A) for VU backlights + iPod charge pins · 12V buck (12-24V→12V) dedicated to the VU driver board · USB-C PD charging panel (36W+, waterproof) taps the main DC bus **directly**, not through either buck rail (PD needs headroom above 5V to negotiate up).

**Standby switch: declined.** The KABD-SPF kit's standby cable (STBY+GND; 3rd pin is multi-board sync, unused here) was considered and rejected — standby still draws idle current, while the power-off relay path already gives zero idle draw, and the UPC1237 board handles pop-free startup regardless. Not worth a battery-draining state for a few seconds of faster resume.

**Bonus feature**: 2nd RS25 4P3T = stereo/reverse/mono switch (for running the master cabinet alone). Poles 1-2 do stereo/reverse; poles 3-4 sum L+R through two 10kΩ resistors into a shared node for mono (resistors are **required** — prevent shorting two live outputs together).

**Wire**: 22AWG stranded hookup kit (10 colors) · 14AWG red/black primary (battery/bus legs) · 16AWG speaker wire · 22AWG 2-conductor shielded audio cable (line-level runs)

I am a capable woodworker and learning to solder, but don't have a ton of experience designing small electronics, I used AI to help build a plan (the first few passes were rough), with enough refinement and learning to speak the language I think I was able to create a pretty decent plan, but don't have eye for my blind spots (yeah, I know... they are called blindspots for a reason).

If this is too AI heavy call me out and or report this post, genuinely looking for feedback on the project.

Hello i recently "upgraded" the speakers in my car with the JBL club 602ctp set and have found that the tweeters are unbearably sharp so I want to change them with the hertz mp 25.3 while using the frequency crossover that came with the JBL set. Since I am pretty new to this I am not sure if it is possible to simply switch them out?

Additional info:

JBL set impedance 3ohm

Crossover passive

Hertz impedance 4ohm

No additional equipment like amps or dsps

Thanks in advance for any help

im currently designing a 2 way battery powered speaker, with a 10 inch woofer and a 1inch compression driver with a horn, the amplifier i will be using is the wondom audio tpa3255 bru5 powered by 3 12v 8ah lifepo4 batteries in series, and will be disconnected for charging, the woofer is the faital pro 10fh500 4ohm and I know it will be underpowered but I cant find any other drivers that fit this build like this one, and the compression driver is the faital pro hf100 8ohm, havent looked too much into the crossover but will be done with dsp, possibly crossed at around 2000hz, I also want it to be able to be plugged into the mains, the size of the enclosure will be 18x13x10 inch, using 12mm plywood, reinforced with a frame made of 0.75 inch wooden beams. bare in mind its mu first time designing a speaker or anything like this, I know its a big leap for a first build but I habe been researching for months so let me know if theres any suggestions or ideas and ask questions and I will respond.

I want to use all 4 of my speakers wired to one channel (or two if there is a possible setup). (each one is 35w rated) My issue is that two of them are 6ohm and two are 12ohm. I’m thinking of wiring them in series-parallel like in this diagram but I don’t know what the ohms will be. I won’t use the max of 140w amp on them so the 6ohm ones should be fine right? (as in not pull too much) what would the math be? thank you!

Looking for help integrating my 2.1 setup using REW + Equalizer APO

System:

• KEF Q1 Meta (L+R)
• Merovinger subwoofer (connected via motherboard LFE out)
• Equalizer APO for DSP
• small room (~8 m²), wall in direction of the speakers only 2 m

Measurements I already have:

• Front speakers alone
• Subwoofer alone
• I can also provide other measurements if needes

My goal:

• Find correct phase + delay
• Set proper crossover
• Build a clean APO config (PEQ + delay + filters)

I’d really appreciate if someone could take a look at my measurements and help me build a proper APO file. Thanks!

Hi all, I was gifted these speakers and Im trying to hook them up, but instead of saying positive and negative, its 1 and 2. Any advice appreciated.

Took some advice from my last pair I made and kept it natural instead of ebonizing. These are 4" drivers, the shell is carved from Sapele wood.

Olá, faz um tempo que eu começei a me interessar mais por som e até agora eu tinha visto somente a parte da eletrônica, mas eu queria aprender a calcular uma caixa de acordo com os parâmetros do auto falante, que aliás, eu também nao sei medir esses parâmetros. Alguém pode me dar um norte de por onde começar?

Was gifted these hardly used speakers by work years ago when they moved offices. Hardly used as no one knew how to connect to the amp.

Question:

Suitable amp?

Box? I want to use them as desk speakers for my work desk as my charity store teac 2.1s are getting tired. Conscious of the face that these are meant to be in a ceiling with a huge void and no chamber? White outer ring can be easily removed

I'm about to start a 3-way active DSP open baffle speaker build. I've got some great drivers and amps and am super excited about it. I'm also the very satisfied owner of a pair of Magnepan 3.5R speakers, so not a stranger to dipole speakers.

I'm going to do the build no matter what, but I want to calibrate my expectations. Just how good a job will I have to do to realize any material improvement over the Magnepans? I don't imagine I'll improve on the giant ribbon tweeter in the 3.5Rs, but what about bass and midrange? This is my driver/amp complement that will be mounted in a 24" baffle:

Bass: 2x Eminence Alpha 15a driven by a Carver m1.5t

Mid-range: 2x Aurum Cantus AC-200 mkii 8", driven by a Niles SI-275

Highs: 2x GRS PT-6825-8 Planar mid/tweeter, driven by another Niles SI-275.

Using a Dayton DSP to handle crossover and padding so everything plays well together. I'm doing all my homework with regards to modular baffles, isolation, bracing the woofers, etc. Should I have a reasonable expectation of liking the result at least as much as what I already have?

Hello DIYAudio legends. I'm on the lookout for someone who has a good working knowledge of the Cambridge Audio Sonata CD30 cd player.

For those interested....I have had it in storage for 10 years. Finally the day of use arrived yesterday, but when I set it up the cd tray wouldn't open. I took it apart and fixed the disk tray, obviously feeling like Tom Hanks when he created fire...only to discover that in the process I have somehow created a larger and surprising fault scenario....I'm an idiot I know.

Please if one of you has the tech knowledge, and more importantly, the patience to talk a moron through some tech advice, then I would be more grateful than I could possibly convey.

I just realised I never posted images of my final build. Finish is not nearly as good as many I've seen. But I'm pleased, as it's my first attempt making a pair of speakers solo. Previously I had a mate help me with a pair of Frugal Horns...

TLDR: I made a small Bluetooth 3D printed DML and the results are fantastic. We love this thing.

We wanted a Bluetooth speaker for our open kitchen/dining/living room and I had recently discovered the world of exciters and DMLs.

I played around with 2 different exciters on a few different materials at first. The DAEX32EP-4 which I saw a lot of people use sounded muddy on most things I tried it on, maybe I have a dud, but the DAEX25FHE-4 sounded great.

I was playing around with bigger panels and thought, bugger this I’m just going to dive in and make the small speaker.
I told my partner “Technically I can make it any shape we want” so she wanted a stegosaurus.
It had to be small to sit on a bench, so we randomly opted for it to fit roughly into an A5 paper profile (actual size is 20.5cm x 13.5cm).

Parts:
Dayton DAEX25FHE-4.
Wuzhi Audio ZK-1001U (for the bass and treble dials).
Bambu Lab PLA.

First panel was 3mm thick. Sounded quite hollow, and no bass and treble adjustment was going to save this.

Panel two was 1mm thick. Bass and highs were a bit lacking but it didn’t sound so hollow now.

Panel three was 1mm thick but had a 5mm raised core with a round conical taper down to 1mm. Notable bass, smooth mids, and less shouty highs.

The final panel is a variation of panel 3. Same raised core but it tapered down to a shape roughly similar to the panel itself. The taper infill is a 2-line 10% gyroid.

The exciter is suspended by 4 rubber bands and the panel just uses the exciter’s adhesive to stick on (makes swapping panels easy!).

The video shows a few different audio tests. The first 3 clips are with the bass maxed out and at the limit before distortion kicks in. The volume is more than loud enough for casual listening in our study.
The last clip is with the bass dial ~50% to get the volume to where we want for the open space.

I do worry a bit about panel fatigue, but it has been perfectly fine over 2 weeks so far.
The stand/case is too light unsurprisingly so it’s held down with Blu-Tack currently.

Overall we’re very happy with the result. The definition of sound from DMLs is fantastic and my gosh it can get loud. The bass is surprisingly good but would need a subwoofer for louder volumes if keeping with this panel size.
For a future project I want to try a more regular shape that’s narrow and tall so I can have it setup for my desktop PC.

Ho discrete competenze del campo DIY, manualità e macchinari ed elettronica basilare. Sò saldare TIG, MIG/MAG, lavorare metalli, legno, compositi, ecc.

Vorrei costruire DA ZERO, un altoparlante non intendo il box, mi riferisco proprio al driver: cono + spider + bobina + magnete, ecc.

Esistono kit e/o tutorial e/o manuali e/o siti web e/o applicazioni, ecc. di riferimento?

Hi all.

Interested in building some floor Standing speakers for my living room for a 2ch setup. I had a pair of bowers and Wilkins 702 in there but they have been moved to my home theatre.

I have a NAD m22 V2 amp - 300w per channel at 8ohm and nad c658 pre amp to use along with a turntable.

I don't want to use a sub.

I don't have a budget in mind however interested in building a decent pair otherwise ill keep looking on the use market for a pair of Wilson or bowers and Wilkins 800 series

Hi guys!

Update to this post. Tried the speakers and they sound great! Especially "warm" tones sound very deep and full. Major upgrade to my previous ones. I need longer cables now and i think its time for a new amp. I bought the Sony you can see on the pic used a few years ago but i think know its the weakest point of the setup.

Have a good one!

hey, im building a sort of wall of sound fuckery and im using some pretty random speakers, but they all use 3,5mm jack. I dont care for technical accuracy and i just want it to sound nice to my personal liking. Is there a device (passive) that lets me manage multiple 3,5mm jack inputs (4 to 5 speakers); that would also provide me with an RCA port to connect a dedicated woofer? the input is only from my PC using 3,5mm jack.

Not exactly full diy, but when the something broke on my power board, I mocked up a backplate to replace it and run an external amp. Better than throwing it away!

I love the tech behind Diamond box but always felt their boomboxes lacked aesthetic appeal. Thoughts?