Open backed (dipole) cabinet for bass guitar

[StigErik]

Anyone tried it and/or want to comment on that?

[cyclecamper]

You'll get cancellation between the two sides, and if you don't put a high-pass infrasonic filter on the amp then very low frequencies from slapping the strings etc. can make slower extreme cone excursions and cause you to exceed xmax.

I don't even like a ported cabinet for bass guitar.

I like sealed boxes for bass guitar, and choose my drivers for the frequency band and box size for Qtc. Very simple and straightforward whether you're going for a pop&slap lead bass with lots of 10"'s like and SVT or a walk line with couple of 15's. A bass guitar doesn't really go too low..

Check out what Orange is doing with compact isobaric cabinets if you want to try something new.

[StigErik]

Its true that a 4-string bass don't go all that low. The low E is "just" 42 Hz. Problem is that most ported bass cabinets I've listened to don't go to 42 Hz. The fundamental is usually lost somewhere around A (55 Hz). Sealed cabinets are better I agree, but I really like the sound of open baffle bass for hifi, so why not try it for bass guitar as well?

My current bass amp - small and cheap - is a laugh. Its a Laney RB2. The 10" woofer has about 1 mm Xmax, resonant frequency somewhere around 150 Hz. The very small ported cabinet is tuned to 120 Hz. And the frequency response of the amp itself is a joke, even with the "bass" control on max it rolls off at the low end. There is simpy nothing below 150 Hz, and they call it a bass amp??

[cyclecamper]

Bass amp is just a LOT harder on speakers, and some SLAM impact is sometimes wanted. Focus used to be efficiency, now it's mostly tone.

I'm not a big fan of dipoles. LInkwitz may differ.

[454Casull]

You could, but it probably won't sound very good in the upper registers. It will be impossible to avoid the pipe resonance of a U/H-frame if using only one driver, and the polar radiation will go crazy above the dipole peak.

[StigErik]

I know... but a regular 15" woofer cabinet is pretty awful off-axis as well, if not worse.

The dipole peak can be handled with parametric EQ or the tone controls of the amp perhaps.

[sreten]

Hi,

Very bad idea, it simply won't work unless your playing in a light jazz combo.

Sealed is standard, depending on the drivers vented an option.

There are some outstandingly poor bass combo's out there, probably lashed
up by a guitar combo designer, with no real idea what they are doing.

Nevertheless, the best compact, loudest and useful for purpose bass
equipment only goes flat to around 80Hz, because for the same flat
to 40Hz it would need to be 8 times bigger, a bugger to transport.

Open backed bass cabinets are awful for modern music. Don't go there.

rgds, sreten.

[454Casull]

Originally Posted by StigErik

I know... but a regular 15" woofer cabinet is pretty awful off-axis as well, if not worse.

The dipole peak can be handled with parametric EQ or the tone controls of the amp perhaps.

Well, yes, once the driver starts beaming, dipole starts to become more and more like bipole... but you can't EQ out off-axis oddities. Also, simple beaming is much smoother, and MUCH more usable, than this:


from http://www.linkwitzlab.com/models.htm

I really can't see any advantages to dipole in this application.

[StigErik]

That model is just a model. It dont look like that in real life. I know, I have dipole speakers, and I have measured them.... but anyway, I get your point. Its not a good idea to operate a dipole speaker above the dipole peak. Hm....... guess I should consider sealed box then, or make a two-way dipole.

Like to add that I'm not after a very loud bass amp, its just for practice and for playing electric bass with unamplified acoustic instruments and voices.

[0feedback]

...speed maybe ?