18" + WAVEGUIDE - 2 Way Bass Reflex 'THE VERSATILE' Loudspeaker.

[The Space Egg Corp]

Hi to all you intrepid DIY audioers out there.

Just as I thought my speaker building days were over, the need for a new loudspeaker has popped up !

Having built a few speakers over the years my current line up has not changed for quite sometime, as I am very happy with them.
They are:-
6.5" Full Range
8" 2 Way Bass Reflex
8" 2 Way Transmission Line

There were a few before these, but they are now part of my carbon footprint !

My new acquisition of a Steinberger 5 string bass guitar, has brought about the need for a new speaker (yes mono) or maybe speakers.

The 5th string on the Steinberger is normaly tuned to B zero, which is the same as the 3rd key on a regular piano, or 30.868 Hz.

I was quite pleased to find my existing speakers did quite a nice job of conveying the Steinbergers full frequency range, from the bottom end, right the way up to the shimmering harmonics disapearing off the top end of the audible spectrum.
What I wasn't pleased about, was that if I carry on playing it through my 'Hi-Fi' speakers, the cones will end up embeded in the rear wall of my listening room !

Conclusion:- New speaker/s needed.

Being an intrepid DIYer I wouldn't even dream of buying a commercial speaker unless the worlds MDF resources were about to dry up, but checking out the competition is always a good place to start.

I won't go into the gory details and the huge expense of speakers I found commercialy offered.
But needless to say I was not overly impressed by anything I found.

However, as a result of seeing what I didn't want, It quickly became apparent what I did want.

What I wanted was an 'audiophile' bass guitar speaker.
Something which would not disapoint compared to my 'Hi Fi' speakers.
Also, a fairly compact speaker which would nevertheless give a pro-audio PA speaker a run for it's money.
And a speaker that could also perhaps function as a decent sub-woofer, and potentialy integrate well with existing 'Hi Fi' speakers.

So the idea of 'The Versatile' loudspeaker is what I am aiming for.

Ah !!! 'The Versatile' loudspeaker, I hear...

Jack of all trades, and master of none, more like...
A guitar speaker without 'character', It'll never catch on mate...
Pro audio PA speaker ? Wot ? you don't need a forklift to move it...
Really ? A 'Hi Fi' speaker with an 18" driver that isn't the size of a wardrobe...

Ideas for 'The Versatile' loudspeaker spec to follow shortly...

Cheers for now

Simon

[The Space Egg Corp]

Speaker building has always seemed to me to be a risky business.
DIY speaker builders are the stunt people of the DIY audio world !
Jumping off tall cabinets, and praying they don't land with a sobering crash.

If your latest pre-amp sounds a bit off, you can always tweek a few bits here and there, and bring it back from the abyss.
If your turntable plays a bit bad, couple o' bucks on a new cart, and your on the rails again.
A big wooden box all glued up with holes cut in it, and expensive (or cheap) drivers installed, can be an impossible fix if it ain't right.

With that in mind, The Space Egg Corp's #1 rule of speaker building would have to be:-

"Weigh out some wedge on yer woofers"

Trans:-
Use the best possible bass driver you can (think of a decent spec, and then double it, at least).
Once you've spent hours (days(weeks)) gluing up a complicated cabinet and making big holes in it, woofers are 99% impossible to change. Tweeters fortunately are more forgiving.

Sorry if all you vets. are nodding off out there, but if someone told me that when I started, I would have more cool speakers to listen to, and less ash on my bonfire !

By the way, before I try to spec. out 'The Versatile' loudspeaker.
I would love to hear from any members who have used any of the following drivers and components in any type of speaker whatsoever, and their opinion of them.
Or who have used, and can give opinions on alternative similar parts.
That to me is what being a diyAudio member is all about.

BEWARE OF THE DOG
IT BITES !
woof woof woof woof

Woofer selection.

1. It has to be suitable for a 2 way speaker.
2. It has to have the absolute lowest possible resonant frequency.
3. It has to have the absolute widest possible frequency response.
4. Needs to have an alloy cast chassis.
5. Largest magnet available for it's cone size is a good sign.
6. It has to be a 'sensible' price (whatever that is).
7. It has to be replaceable, and (fingures X'ed) available for years to come,
8. Doesn't have to be light (am not going to use them for dumbells).
9. Power handling ? (not an issue, never seen a 1W 18" speaker).

Mmmm....is that all the main points ?

In our next thrilling episode, meet the 'Eminence Sigma Pro 18A-2'

BEWARE IT BITES !

Cheers

Simon

[Godzilla]

http://www.parts-express.com/pdf/295-036s.pdf
http://www.parts-express.com/pdf/290-427s.pdf

Maybe use one of these and partner it with the Econowave tweeter. They appear to have extension past 2k and the Econowave crosses around 1.6k...

There, i figured it all out for you... lol

[The Space Egg Corp]

Originally Posted by Godzilla

http://www.parts-express.com/pdf/295-036s.pdf
http://www.parts-express.com/pdf/290-427s.pdf

Maybe use one of these and partner it with the Econowave tweeter. They appear to have extension past 2k and the Econowave crosses around 1.6k...

There, i figured it all out for you... lol

Hi God

Thanks for your interest in 'the versatile' loudspeaker.

I checked out the PDF links you gave.
One is the data sheet for the Eminence Sigma Pro 18A-2 in this thread.
The other PDF I'm not sure what it is, as having tried it a few times would not open.
Can you let us know the subject of the other PDF ?

I googled 'econowave tweeter' and found myself at a thread started by yourself at diyAudio.

I see you proposed using an Eminence 'Lil' Buddy tm.' 10" on an open baffle with an econowave tweeter.

The 'Lil' Buddy tm.' is a guitar cabinet driver similar to the amusingly named 'Cannabis Rex tm.' both from the 'Patriot' range of guitar drivers by Eminence.

The 'Lil' Buddy tm.' has a resonance of 149 Hz, an intentional 'character peak' at the musical note D3, playable on the 3 low strings of a regular guitar, and all strings of a bass guitar (30th note on a regular piano key board).

Are you a guitar player, or are interested in guitar speakers ?

Whilst using the 'Lil' Buddy tm.' for 'the versatile' loudspeaker would be unsuitable.
I am intrigued to learn your reactions to using this guitar driver on an open baffle 2 way, for example how large was the baffle and what did it sound like etc.

Eminence make a bafflingly huge range (sorry) of such 'character peak' drivers, this one interestingly going to 5K, that finding one with the 'right' character seems like walking into a minefield.

Cheers

Simon

[Josephjcole]

Econowave

[Godzilla]

Thank you Joseph for posting the right link to the econowave project.

Simon, i never got around to trying the Lil Buddy... I don't think it will work at all in your proposed project either. I read it sounds good on OB with helper woofer and tweeter.

The link that won't open for you is a Dayton 18" driver similar to the Eminence. They both extend somewhat past 2k... most of the others did not go past 1k.

[freddi]

I play bass. Here's two speakers with 18" and a waveguide. Moving mass should be as low as possible and motor strength as high as possible.

The Karlson open-end waveguide was patented as a microwave antenna.
Stanley Clarke used Karlson-couplers at one time and apparently at first a different set than seen in a common picture

both 18" have good fidelity with the 1.875"x9" long slotted tube - moreso than a lot of "fullrange" stuff

[DougL]

Doesn't an 18" driver beam at less than 800 Hz?
Wouldn't you need a compression driver that allows a ~500 Hz cutoff and an 18" waveguide to match?
I would think a 3 way would be more practical with an 18", but that's just me.

Doug

[The Space Egg Corp]

Originally Posted by DougL

Doesn't an 18" driver beam at less than 800 Hz?
Wouldn't you need a compression driver that allows a ~500 Hz cutoff and an 18" waveguide to match?
I would think a 3 way would be more practical with an 18", but that's just me.

Doug

Hi Doug

Yes I had wondered about beaming.

A product I noticed recently and was intrigued by is the 'Tayden Sonic Diffuser'.
These are available, I think, only up to 12" diameter.
They are intended to be fitted to guitar cabinet type speakers to deflect unwanted beaming sideways.

I did wonder If I could lash together my own DIY beam deflector for an 18".

Just noticed also Dayton Audio produce a big 12" circular waveguide which looks interesting. They quote crossover at 1.2k Hz.

I umed & rred about a 3 way, but, would love to try a 2 way, and get away without a 3rd driver. Mmmm?

Cheers

Simon

[The Space Egg Corp]

Hi again Doug

& anyone who was wondering what a 'Tayden Sonic Diffuser' is.

Here's a picture of one.

Basicaly a pointy pyramid type exponential cone type thingy in reverse, if you get my drift.

DIY pointy shape held by dowel or alloy rods, fairly easy to lash up by the looks of things.

I Read feedback from several happy customers on the net, who said their beaming problems were gone !

Perhaps the DIY version could be called 'The Beam Be Gone', groan...

Cheers

Simon