Tiny full range drivers..like 1-2" tiny.

[danosix]

Your math is wrong it's pi(r)(r) - (pi x r squared) - so a 15 is about 150" and an 8 is about 50.
You also want to take out the area inside the coil so realistically if you double the diameter you quadruple the area so 4 8s would be ever so slightly more than a 15. The other thing to take into consideration is throw - the speaker needs to move more forward and backward for the big frequencies and more so if it's small.
That's why the 8 in the baby blue is so expensive it's a purpose built bass speaker with LOTS of throw and power handling.
I totally get the appeal of a bunch of wildly undersized speakers, but do this for fun - not for an effective cabinet.
Also - stereo speakers have very different demands than instrument (esp bass) speakers and so they are much less efficient and don't need to be nearly as robust as they don't get the huge changes in volume (transients) that instrument speakers experience.

 

[dincz]

Your math is wrong it's pi(r)(r) - (pi x r squared)

We've been there.

 

[Mark_70]

This reminded me of an article I read on a 50cc V8 engine.
We'll need to see some pictures when you're done with this project

Regards
Mark

 

[Coolhandjjl]

Everyone I know who just gets into acoustics want to build a wall of 1" drivers. Everyone. Why is that?
Anyway, all the reasons given are good, and I will add to that that getting the waves from each driver to couple properly is an issue also. You will have pistonic beaming issues as you add more.

 

[GrumpiusMaximus]

The other issue is that you need the size to get a good bass extension, unless you go with a ported design. The issue with ported designs are twofold. Firstly, you need a well-sealed cabinet and secondly you need to tune the port properly. Bad port designs tend to only resonate well with one frequency and multiples thereof so you can end up with a very one-dimensional low-end response. Then you also have the issue of bass phase interference with multiple sound sources.

I think you're better off with a small array of small drivers (say four - just off the top of my head), a passive crossover and another array of bass speakers. You'd probably want to put some kind of limiter on the smaller speakers depending on your crossover frequency.

 

[trevcda]

You will have pistonic beaming issues as you add more.

Here you go. 42 two inch drivers flanked by a pair of five inchers. Not exactly bass worthy sound but is able to beam multiple channels around a small room to present five channel surround. Still needs a sub for bass, but I thought it might add an interesting dynamic to the thread.

 

[will33]

Here you go. 42 two inch drivers flanked by a pair of five inchers. Not exactly bass worthy sound but is able to beam multiple channels around a small room to present five channel surround. Still needs a sub for bass, but I thought it might add an interesting dynamic to the thread.

Beam soumd alrighty.

That thing should be layed out in a sort of "shallow horseshoe", wrapping around the listening area.

 

[pie_man_25]

Everyone I know who just gets into acoustics want to build a wall of 1" drivers. Everyone. Why is that?
Anyway, all the reasons given are good, and I will add to that that getting the waves from each driver to couple properly is an issue also. You will have pistonic beaming issues as you add more.

I've been getting into amateur speaker designing, and I've never really considered the idea. It just seems too impractical, drilling/cutting all of those holes (at that size a hole saw would probably work though), not to mention - making sure that they're all wired in the correct polarity etc... , just seems like an artichoke - a lot of work for comparatively little good stuff. That said, 1" drivers also have their use, but IMO simpler=better for this sort of thing. Plus, it's been mentioned before - bigger speakers are more cost effective than lots of smaller speakers, or at least, they tend to be.

 

[Timmah]

If you're looking for 3.5" - 4.5" drivers with enough xmax you should try one of these.

Invalid Link Removed (excellent driver IME)

http://www.parts-express.com/dayton-audio-rs125p-4-5-reference-paper-woofer-4-ohm--295-371 (good choice IMO)

http://www.parts-express.com/dayton-audio-ds115-8-4-designer-series-woofer-speaker--295-424

Invalid Link Removed

Don't expect such a design to be able to handle a low-B, a normal 4-string should be doable.
I would at least build two Bose 800 type of enclosures (16 x 4" drivers in total) else the SPL will be to low.
Btw. another problem with most of these small drivers with low enough Fs is their suspension properties. Most of them have a "linear" supsension and for PA/Basscab use, you want it to be "progressive" at least from the moment the voice-coil starts to leave the airgap. This will protect the driver from mechanical abuse.

I wonder if a little desktop combo with one of these in it would sound good- it would be tiny but cool.

 

[Feral Feline]

I wonder if a little desktop combo with one of these in it would sound good- it would be tiny but cool.

That's what I've always wanted to do (and the reason I came to this thread)... get a single PJB Piranha driver from a wrecked cab and have somebody else build for me a mini-cab for it. Hook up a 1w or half-watt mini-tube head for some desktop/office/bedroom/living room bassy goodness.

View attachment 518931 I think they are Baller!

These would be of more interest if they were inverted, ie the speakers facing each other in a cross-firing arrangement ... just a thought, as I've no real idea 'bout this speaker-physics stuff.

 

[lomo]

The smaller the driver, the higher the ratio of weight of metal/weight of paper cone. PJB speakers sound good, but are less efficient, heavier , more complicated (and often more expensive) than other top quality speakers with similar or greater output. They sure do look cool though.

 

[lomo]

I have owned PJB suitcase combo with ext and a 9B cab-sold 'em both 'cause there just wasn't enough volume per pound or dollar. Now I do have a double 4, and IMHO that's where PJB excels...applications where even one 8 or 10" speaker will make the box bigger than desired. Once the box could accomodate an 8 or 10" speaker, KJung's description of PJB comes to mind: "...a bad idea, beautifully executed"

 

[Foz]

I totally get the appeal of a bunch of wildly undersized speakers

I am immune to the charms of this concept... appeals to to me about as much as the idea of "wildly undersized" shoes.

 

[will33]

Few years back somebody on here made a 16x5" using some fairly inexpensive hifi woofers from Parts Express. It went really low, and quite high for no tweeter, and really smooth on axis, but the whole cab only added up to something like 98db@1watt due to the low (86-ish db) sensitivity of the drivers.

They were aluminum cone 5" and 16 of them added up to something like $300.

My memory is foggy but there is an old thread on it around here somewhere.

 

[will33]

Was these drivers.

Invalid Link Removed

Only need about 1/3 cu.ft. per to reach into the 40's, but they are soft suspension, low spl hifi woofers. Need lots of them to get respectable output and mechanical power handling, but 2 or 4 could make a cool little home practice cab that is very small and plays deep. Could be cool for a low power practice amp or little 5 watt tube amp or something.

 

[Coolhandjjl]

BigE designs use an array of 5" or 6" drivers in a cross-fired baffle, they go really low. But they also have that rear mounted waveguide integrated as part of the design as well.

 

[will33]

Apparently I had done some modeling for them in this thread.

http://www.talkbass.com/threads/flat-practice-amp-speaker-cab.613819/

So there ya go..... .33 cu.ft per driver, tuned 48hz, times however many you need to get where you want to go.

Not Prosound drivers but will work for small low power stuff. Basically a "book shelf" speaker that'll do widerange bass guitar with no tweeter needed. Simple little "speaker in a box".

Keep the power low as hifi drivers aren't very good at handling live instrument transients. Easy to bottom them out.

 

[Coolhandjjl]

Keep the power low as hifi drivers aren't very good at handling live instrument transients. Easy to bottom them out.

That's what separates the men from the boys. The initial config of the Dead's WOS fried the tweets due to transients.

Anyone ever take a look at the backside of a Cerwin Vega 15" woofer from their D9 home hi-fi speaker? It looks like a toy compared to a pro audio 15" woofer. (Even the 12" driver in my 1975 JBL L100s looks more robust than that D9 driver, but again, that's JBL.)

 

[will33]

That's what separates the men from the boys. The initial config of the Dead's WOS fried the tweets due to transients.

Anyone ever take a look at the backside of a Cerwin Vega 15" woofer from their D9 home hi-fi speaker? It looks like a toy compared to a pro audio 15" woofer. (Even the 12" driver in my 1975 JBL L100s looks more robust than that D9 driver, but again, that's JBL.)

Yup.

They're not designed for live sound but can work for low volume home practice stuff. You get the tiny size with real low end at the expense of (a lot of) spl.

A pair in an MTM layout with a soft-dome tweet could make a nice inexpensive stereo speaker. I'd once thought of making a fleet of them to spread throughout the house. Wouldn't take up any space and could have a volume control for each room but I never followed through with it.

Found an old pair of Realistics that have a passive woofer and 4 powered electrostat tweets, and an old pair of KLH 2-ways with cone tweets, all on the curb for free , I wanted to refurbish instead but haven't got around to doing that either.

They're still taking up space in the storage unit.

 

[DukeLeJeune]

Here you go. 42 two inch drivers flanked by a pair of five inchers. Not exactly bass worthy sound but is able to beam multiple channels around a small room to present five channel surround. Still needs a sub for bass, but I thought it might add an interesting dynamic to the thread.

I'm pretty sure they use some DSP-implemented steering algorithm to beam the side surround channels off at an angle so that you get the wall bounce to mimic a sound source in that location. Like to hit a side wall, you'd send that signal to widely-spaced drivers (to get a narrow pattern), and then delay the drivers on the same side as your target wall by an amount that would pull the in-phase axis over to the desired angle.

Probably doesn't work as well as the real thing, but takes up a lot less space.