1×6″ Astoria Cabinet

I love how my 1×10″ cabinet sounds, but the Celestion G10 Vintage in there gets too loud for my apartment even with low power (1-3W) tube amps. Guitar speakers are usually quite loud. The measure in the specs that tells us how loud they are is “Sensitivity”. Generally it’s expressed as decibels per one watt of power measured 1 meter away from the speaker. G10 Vintage and most other Celestions are rated around 97db, some Eminence go up to 102db. That’s for 1W of power only! At the time I was building my 10″ cabinet, my main goal was to find a smaller speaker sounding close to the V30 without worrying much about the sensitivity. And I got a great sounding speaker that’s too loud for most situations in apartment.

This time I wanted to try and build even smaller cabinet with an even smaller speaker, but find one that has noticeably lower sensitivity than the Celestion. Weber Signature Ceramic speakers should have sensitivity around 94db, they go down to 8″ in size and I know they sound good because I have one in my Princeton build. But then I came across a relatively new model from Jensen, called C6V, that was announced back in 2015. Generally I don’t find Jensen speakers too interesting, probably because they are rarely used in amplifiers I gravitate towards. But this one seemed interesting – warm and clear with late breakup and slight mid cut. I don’t want the speaker to distort on its own too much, like some Jensens do and I don’t want it to sound brittle. And the rated sensitivity is only 91db. That means that with the same amplifier, it will output about the quarter of the volume of the Celestion. They have a similar 6″ model from the MOD line with sensitivity even lower, at 90db, but the C6V sounded nicer at least on the demos. So I ordered one and started designing the cabinet while waiting for it to arrive.


Using this closed box calculator with the specs from the Jensen website I calculated that a cabinet with internal volume or around 8 liters should go down to ~100Hz and that should be sufficient for guitar. Using a strict rule of multiplying sides by 1.61 I got close, but had to make height a bit bigger to make sure the speaker will fit. That should be fine as we’re not dealing with Hi-Fi here. A friend gave me a nice spruce plank 16mm thick. Going thinner on such a small cabinet may be better because it will allow the whole cabinet to be “livelier” and resonate more than a big slab of wood. Again, something we might not want in Hi-Fi world, but could be beneficial for guitar. To make it more flexible, the back side is separated into two parts. Removing one of them converts the cabinet from closed to open-back.

Visual Design

I wanted to make something nice and being too lazy to design something from scratch, I just browsed the web for cool amp designs to adapt. Few models stood out, but I liked Marshall Astoria line the most, so I set the goal to build a sized-down version of similar design. Marshall makes them in few cool vintage pastel-looking colors, but finding good tolex is not an easy task. Usually you can get bright colors that aren’t very interesting to me. The closest color I could find was TubeTown.de “Candy Green” shade that has a bit of olive and less saturated, in-your-face than the usual green tolex.

As the final touch, I made a laser engraved nameplate and tinted the letters green with a fine permanent marker.

8 Responses to “1×6″ Astoria Cabinet”
  1. Matthew Quinney says:

    I got to your site when I googled the Blackstar Fly mod and saw your article for adding an external speaker. I would like to do this, but I am completely new at guitar. The Blackstar Fly is my first, and only amp. I therefore haven’t a clue what size speaker to use. I noticed you have the Blackstar with this speaker cabinet, would you recommend this size speaker for the Blackstar? Thanks, Matt

    • bancika says:

      Depends on what your needs and restrictions are. It’s more than capable of driving even a 4×12″ cabinet and that will probably sound the “best” and the loudest. I went for small size and low sensitivity speaker to be able to get fuller sound of of my amps at reasonable “TV” levels for my apartment. It still sounds louder than Fly 3 speaker but also much fuller. One thing to notice is that the small driver in Fly 3 is probably some full-range driver that has much more highs than any other guitar speaker and they are most likely compensating that by cutting some high frequencies in the circuit. If you are building a cabinet dedicated to Fly 3 only, maaaybe you’d be better off using some full-range driver. I haven’t tried myself, but I’m guessing. With a dedicated guitar driver we are cutting treble both internally and the driver itself cuts highs, so I find the sound lacking a bit of presence. Not much, but I think it’s there. I still prefer to use it with the cabinet because the sound is much fuller, but I modified Fly 3 again to be able to run the external speaker in addition to the internal speaker…so external one gives fullness, the internal one adds some top end fizz 🙂

      • Matthew Quinney says:

        Thank you for the information! I like building things but until now I’ve dealt mostly with wood. This is my first foray into electronics. Also thanks for the tip of using both internal and external speakers to preserve highs. One more quick question, if you use both, should the speakers be in series or parallel?

        Many thanks, Matt

        • bancika says:

          I wired them in parallel, but added a 4ohm in series with the internal speaker, so total impedance remains at 4ohms and internal speaker is a bit quieter because of the resistor…which is good.

  2. ando says:

    where can i find the circuit or the schematics ???

  3. Steven Williams says:

    Any chance you could tell me where you found “Candy” green Tolex?

    Thanks! Steve

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    The idea behind this site is to share my experience with Do It Yourself approach to guitars, amplifiers and pedals. Whether you want to save a couple of bucks by performing a mod or upgrade yourself instead of paying a tech, or want to build your own piece of gear from scratch, I'm sure you will find something interesting here. Also, this is the home of DIY Layout Creator, a free piece of software for drawing circuit layouts and schematics, written with DIY enthusiasts in mind.