Tiny practice/acoustic session cab DIY ideas

[Beer of the Bass]

I do a little bit of playing in "acoustic" type settings, in which I either play double bass (often unamped) or bass guitar through my GK MB200 / Wizzy 10 setup. Since the space is often limited and I'm typically running the amp barely-on, I've been musing over whether I could use something even smaller for these sessions. It would be used for bringing up bass guitar to a level where it can work with acoustic guitar and light percussion, or adding a tiny bit of reinforcement and monitoring to the double bass in drummerless settings. I'm not looking for something to hang with full drums and electric guitar here, more the sort of setting where a small practice amp would suffice.
On a whim, I've picked up a couple of lightly used Faital 6FE100 drivers to experiment with which were going cheaply on eBay. The specs of those are here:
[url="http://www.faitalpro.com/products/files/6FE100/8/6FE100_datasheet_8.pdf"]http://www.faitalpro...datasheet_8.pdf[/url]

These have respectable X-max, (so a pair could have similar displacement to many 10"s), 100 watts thermal handling but fairly low efficiency at 91dB. Modelling them in WinISD, I found that putting a single driver in 9-10 litres tuned to 50Hz gave me low end response which is probably OK for this application (-3dB at around 70Hz, with a mid-bass bump of less than 2dB). Maximum SPL is 106dB at 80Hz, rising to about 110dB above that.
I'm going to do this in salvaged/scrap plywood first to try the concept without spending too much. At the moment I'm not sure whether I'll get a useful amount of output with one driver in 10 litres, or whether I should use both from the start. I suspect one of the biggest challenges will be fitting a large enough port in the box to avoid chuffing. I may also try them sealed, which gives a higher roll-off but a smoother response with no bump while conveniently side-stepping the port size issue.
I'd be curious to see whether anyone thinks this idea has legs or if it looks like an exercise in futility!

Edited April 18, 2015 by Beer of the Bass

[CamdenRob]

[quote name='Beer of the Bass' timestamp='1429012302' post='2746956']
...or bass guitar through my GK MB200 / Wizzy 10 setup.
[/quote]

No idea about all that techinal stuff you just asked, but I also use an MB200 / Wizzy 10 setup for acoustic style gigs and it's great. I reckon it's the smallest usable set up you can get away with (except perhaps one of those PJB jobbies).

I did try out a few practice amps etc but none of them made my bass actually sound like a bass, just a nasty honky twang.

[Beer of the Bass]

[quote name='CamdenRob' timestamp='1429013081' post='2746971']
No idea about all that techinal stuff you just asked, but I also use an MB200 / Wizzy 10 setup for acoustic style gigs and it's great. I reckon it's the smallest usable set up you can get away with (except perhaps one of those PJB jobbies).

I did try out a few practice amps etc but none of them made my bass actually sound like a bass, just a nasty honky twang.
[/quote]

Yes, the Wizzy is a nice piece of kit. This project is driven more by curiosity than any real desire to replace it.
Also, coming up with something plain looking and low in value could have its uses - during August when the Edinburgh Fringe is on I've often ended up leaving gear stored in various places to avoid lugging it through the crowds each time.

[eude]

What about one of those Crazy 8 cabs?...
http://greenboyaudio.com/cabdetail?model=Crazy8
Trick Audio, here in the UK make them from £375 up.

Eude

[razze06]

PJB seems to be able to get nice tone from very small speakers in small enclosures. I guess it's all down to materials and bracing.

Alternatively, I found some joy with the roland microcube. It doesn't sound as nice as the PJB combo, but it will do in a pinch. You are welcome to try mine, since we're both in edinburgh.

[bassace]

[quote name='eude' timestamp='1429020083' post='2747085']
What about one of those Crazy 8 cabs?...
http://greenboyaudio.com/cabdetail?model=Crazy8
Trick Audio, here in the UK make them from £375 up.

Eude
[/quote]

Yes, I've got a Crazy 8. I use it lot with DB. It seems to have more bottom and thump than the Wizzy 10. A great cab.

[CamdenRob]

[quote name='bassace' timestamp='1429026795' post='2747177']
Yes, I've got a Crazy 8. I use it lot with DB. It seems to have more bottom and thump than the Wizzy 10. A great cab.
[/quote]

Interesting... Have you tried it with electric bass?

[bassace]

[quote name='CamdenRob' timestamp='1429027046' post='2747185']


Interesting... Have you tried it with electric bass?
[/quote]

No CR I haven't. The OP referred to use with an acoustic and I replied with that in mind. However, if the Crazy 8 is a good substitute for a Wizzy 10 I'd have thought that it would be good for an electric. I've got a mag PU on my Kolstein and I'll try to give it a go over the next few days. I'm gigging the K on Friday so may take the 8. (Was planning to use the Genz which works very well with it).

[Guest Jecklin]

The cab peeking in the top left of the picture link below was built for precisely the purpose you describe beer of the bass - to reinforce my double bass in specific situations.

I made it in 2005 using whatever the 8inch eminence bass driver Maplin sold back then mounted in the perfect size box with a very thick baffle and plnety of bracing ( and wadding etc).

Sounds brilliant.

The cabinet was one of the self assembly modular drawer things that IKEA sold at the time for £6.

I have used it with electric bass and my contrabassoon and it travels to all my gigs now.

8ohm, 150 watt, not especially efficient though.

[url="https://instagram.com/p/zFeb2mhjVu/"]https://instagram.com/p/zFeb2mhjVu/[/url]

Edited April 14, 2015 by Jecklin

[Guest Jecklin]

Just done some fag packet maths and with the big port my cab is about 15.5 litres.

If IKEA still sell these things (a decade on who knows?) It is a really easy way to get a light, stiff box to mount both your drivers in.

[Beer of the Bass]

[quote name='Jecklin' timestamp='1429030654' post='2747221']
Just done some fag packet maths and with the big port my cab is about 15.5 litres.

If IKEA still sell these things (a decade on who knows?) It is a really easy way to get a light, stiff box to mount both your drivers in.
[/quote]

That looks like a neat little cab, though if I do a 2x6" I'm looking at something just a couple of litres more than that so perhaps the IKEA option isn't for me.

Just for the sake of comparison, I've been playing around with a simulation of the driver and box size used in the Crazy 8 cab, though I've had to guess at what their port tuning might be. It looks like a similarly sized 2x6" cab with the 6FE100 drivers might do a somewhat comparable job, though the low end response of the 2x6" is less smooth with a small mid-bass bump.

Edited April 16, 2015 by Beer of the Bass

[ahpook]

[quote name='Jecklin' timestamp='1429029493' post='2747207']
The cabinet was one of the self assembly modular drawer things that IKEA sold at the time for £6.
[/quote]

I doff my hat to you sir !

[Annoying Twit]

I can see how much more people on this thread know about amps and cabs than me. But, can I express surprise as to what people consider the minimum amplification for an acoustic gig. I attended an event where a ukulele orchestra was playing in a moderate sized tent. There was one person playing a Kala u-bass, through a very small amplifier. I would guess something with a 10" speaker at most, but I think maybe an 8" speaker. Their volume held up very well against what might have been 20 or so people playing ukuleles and I didn't notice that it sounded inappropriately weedy. Usually I go to electric gigs with a notable bass stack, but for that acoustic gig I did note the small size of the amplifier but still sufficient bass sound.

By 'acoustic gig', I'm presuming that all the other instruments are un-amplified. I'm aware that you need a goodly number of watts to compete with a loudly played un-amplified drum kit. But for a quiet acoustic gig, wouldn't the drummer be playing quietly?

Edited April 16, 2015 by Annoying Twit

[Guest Jecklin]

[quote name='Beer of the Bass' timestamp='1429178694' post='2748746']


That looks like a neat little cab, though if I do a 2x6" I'm looking at something just a couple of litres more than that so perhaps the IKEA option isn't for me.
[/quote]

A better view if the "ghetto crazy8"
https://instagram.com/p/1iFfBxhjYQ/

I could possibly have got another litre from the box by moving the baffle flush with the box edge, but yes if you need 20litres this box won't suffice sadly (Luckily 15.5 was exactly what I needed).

This is 6mm ply and with good bracing it is stiff and light. If the speaker could take more power then a thicker walled cab may be needed.

Would you wire your 2 speakers up to give a 4ohm cab?
I really reckon you should get something together - I'd love to hear the results.

@ahphook cheers man!
@annoyingtwit once one gets out of amplified music world it is scary how little power you need to be heard. I think this is because acoustic instruments have clearer frequency ranges - an acoustic guitar can't turn up the bass knob and infringe in the double bass for example.

Drummers who have only played with electric guitarists have learned to play as loud as possible to punctuate the amplified volume, where as a drummer used to playing with clarinets and pianos etc will have a very soft touch and be able to coax a full sound from the drums, but at an appropriate volume.

Had you seen the uke band in a solid room rather than a tent the bass would probably have sounded even louder.

[Annoying Twit]

Thanks @Jecklin.

Just out of curiosity, for an acoustic gig with no drummer or a quiet playing drummer in a small performance space, would something like an Ampeg BA110 be useful?

Edited April 16, 2015 by Annoying Twit

[stevie]

The Faitals are probably not a great choice for bass guitar. They are more more suited to a studio monitor and you really need an enclosure volume of around 25 litres (each) to make the most of them. They would work in a smaller reflex box, but you'll struggle with porting (as you stated) if you go below 15 litres per driver.

To get something compact, I'd be tempted to try a sealed box of around 15 litres using both drivers. The shallowness of the sealed box slope should compensate for the high rolloff. For home practice use, sealed cabinets tend to sound less 'lumpy' than reflex, although they obviously won't go as loud.

For home practice I am finalising a small cab with an 8" driver not too disimilar to Jecklin's. OK - it's a bit more pro, but the idea's the same. I'll post some pictures later and if anyone's interested in building one, I could also post some DIY plans on another thread. There are a few good, inexpensive 8" drivers out there that would work. It would also be interesting to know if that IKEA drawer is still on the market.

[Guest Jecklin]

Hi annoying twit, do you own that combo already?

I reckon it would be fine.
Are you doing an acoustic session soon?

Another thing you might notice is how much more of an effect your right hand (assuming you're right handed) can have of on how the bass sits in the the band sound.

In an amplified setting that's going for it you always need a certain amount if attack to punctuate the sound.
As the overall sound level reduces you can ease up your attack somewhat.
Depending on the material you are playing and with what instruments you may find you are moving your right hand around a lot more, ie over the neck more often letting notes bloom.

Have fun!

[stevie]

Here you go. This is fitted with a 200-watt neo driver. Despite its diminutive size, it can easily shake the doors and windows. The trapezoidal shape is useful but optional. Who needs a practice amp?

[IMG]http://i58.tinypic.com/15rnuhj.jpg[/IMG]

[Guest Jecklin]

[quote name='stevie' timestamp='1429192681' post='2749044']
Here you go. This is fitted with a 200-watt neo driver.

[IMG]http://i58.tinypic.com/15rnuhj.jpg[/IMG]
[/quote]

SWEET!!!
What driver do you have in yours?
Mine won't last forever so I'll be keeping my eyes peeled for something to chuck in the cab (modify the cab' volume as necessary)

Edited April 16, 2015 by Jecklin

[stevie]

It's the P.Audio E8-200N. http://www.p-audio.co.uk/pdf/E8_200N.pdf It works well in 15 litres - you probably wouldn't have to change anything.

Edited April 16, 2015 by stevie

[Beer of the Bass]

[quote name='stevie' timestamp='1429190847' post='2749014']
The Faitals are probably not a great choice for bass guitar. They are more more suited to a studio monitor and you really need an enclosure volume of around 25 litres (each) to make the most of them. They would work in a smaller reflex box, but you'll struggle with porting (as you stated) if you go below 15 litres per driver.

To get something compact, I'd be tempted to try a sealed box of around 15 litres using both drivers. The shallowness of the sealed box slope should compensate for the high rolloff. For home practice use, sealed cabinets tend to sound less 'lumpy' than reflex, although they obviously won't go as loud.
[/quote]

There does seem to be a juggling act when looking at ported vs sealed with this, as the extra output from a ported design could be irrelevant if the port is making noises before that point. I looked at putting them in around 18 litres, ported at 50Hz with a pair of 51mm round tubes. This provided about the best compromise I could find, but with an input of 100 watts the port velocity becomes too high below 50Hz. That could be worked around with a high pass filter, but the sealed design might be a more elegant solution. It may be that I don't need a lot of low end in these settings anyway as we're talking about something for quiet use.

Regarding the IKEA drawer, I'm not sure if they do it any more but the closest thing I've seen is this 30x30x20cm solid birch wall cabinet. It would need a baffle and I suspect the back will be very thin. I probably won't try it, but I'm sure it could be adapted with a bit of tinkering!

[url="http://www.ikea.com/gb/en/catalog/products/30252360/#/30252360"]http://www.ikea.com/gb/en/catalog/products/30252360/#/30252360[/url]

Edited April 16, 2015 by Beer of the Bass

[Beer of the Bass]

Hmm, having looked up the price of that P-Audio driver I'm now wondering whether I should punt the Faitals on eBay and look at one of those! That's very well priced for a neo driver, and the high mid and treble response looks like it would be nice and even for acoustic instrument use.

Edited April 16, 2015 by Beer of the Bass

[stevie]

That's not a bad idea. The cheaper P.Audio ceramic 150-watt driver looks quite good too, but I don't think you can go wrong with the neo - especially when you consider the price of the Crazy 8.

[MoonBassAlpha]

So, in use, what is the P-Audio's top end like?

[Beer of the Bass]

I had a bit more of a play around with WinISD, comparing the Faitals I already have at hand with the P-Audio driver. I think the Faital 2x6" might still be worth a shot, considering that they're sat here waiting to be used. In a 16l sealed box they get as loud as the P-Audio (which I modelled in a 16l box tuned to 45Hz) from 80Hz upwards, both in terms of efficiency and maximum SPL. A bit more low end is available if the box is a couple of litres larger and ported, but since I'm going for small rather than loud here I think I'll try them sealed first. It's not going to push much fundamental, but it looks like it should be quite even sounding from the first harmonic upwards and would make for a nice slim box to tuck under my arm and get the bus with, or to squeeze into tiny spaces.

Edited April 17, 2015 by Beer of the Bass