[mresseguie]

My experience with single driver speakers is pretty limited, so feel free to educate me, warn me, encourage me, or....?

If I wanted to try out a single driver speaker, which size driver should I consider? I see lots of folks talk about 5" drivers. I once heard a magnificent 12" (or was it 15") speaker at a show that stopped me dead in my tracks.

Boxed or OB?

I've been perusing the Commonsense Audio website for ideas, but no answers so far.

Thanks for any insights.

Michael

[FullRangeMan]

12 and 15'' FR have a impressive mid and midbass presence along with great transient capability and in a big BR box the bass is superb, better bass (under 200Hz) is only avaliable with a 15'' woofer as DeltaLite 2515 or Faital 1515PR400 or Beyma 15P80ND in a big BR box.

I have choosed the Classic 10 Alnico though due I dont liked the 12/15 Classic versions due the early bass drop at around 100Hz.

This may help:
http://www.glowinthedarkaudio.com/audionirvana.html

[ohenry]

I think an elegant implementation is a small 4-5 inch dia. driver in a back loaded horn cabinet.  You get wider dispersion from the smaller diameter and lower excursion that doesn't muddy the mids and highs.  Being a horn, the bass is enhanced and the driver doesn't puke above 85dB.  And, the speaker has a small footprint.

A nimble sub can easily make more bass for you.

If you like the lighter side of music, a ported cabinet is a simpler option.

[ohenry]

double post...

[FullRangeMan]

Boxed or OB?
Best box for big bass is a large BR box (over 100L) that will built a deep bass, in this case it fit well with big drivers from Commom Sense 10/12/15 FRs.

OB is a great opportunity to use a 15'' woofer as Delta Lite 2515, Faital 15PR400 or Beyma 15P80ND in a big BR box with a 6/8'' FR in OB over 270Hz, the boxed woofer will delivery fast 99dB sensitivity not 94dB as in OB.

I favor the Beyma 15P80ND woofer why it is easily avaliable here.

[FullRangeMan]

Faital and two Beyma, all Neo magnets.

[datman]

I am using a pair of Audio Nirvana 15 inch alnico Classic drivers in a 5.6 cubic foot box with a six inch port. After 2 1/2 years, I have no regrets about having these put together. They continue to sound astounding on just about everything.

I also have a Don Sachs amp and preamp. They are an excellent match for my speakers.

By the way, Don listens to these same speakers. We discussed my speakers before he bought his.

[WC]

Like all things in audio. It depends...

Typically the smaller the driver the better high end it has, the less power it can take, and the less efficient the driver. They work well in small rooms or with near field listening. They can produce decent bass in the right enclosure.

The middle size drivers do reasonably well in the high end, are more efficient than smaller drivers, and can take more power than the smaller driver. They can work well on their own in mid size rooms in the right enclosure.

Larger size drivers can lack some high frequencies so to combat that many drivers will add a whizzer to the driver for the high frequencies. They are generally more efficient and can handle more power. They are the only ones that can be listened to in OB without bass support. They are the best bet for low watt tube amps.

I went with mid size drivers 4" to 6" for my home theater speaker builds. They can be used on their own in my room and I can high pass them for higher volumes and use subs for the low end.

Most full range speakers are missing either form the low end or the higher end. You won't get speaker driver that can get 20-20k, but you could get 30-18k at moderate volumes.

[JLM]

There is no perfect speaker.  And there is no perfect size for a single driver.

60 years ago 80-8,000 Hz was considered full range, making single driver designs much more viable.  Nowadays marketeers have convinced us that full range is 20-20,000 Hz.  So it's the laws of physics versus individual expectations.

I commissioned and still own single driver speakers that use Fostex F200A 8 inch (whizzerless) AlNiCo magnet drivers (89 dB/w/m, 8 ohm, 30-20,000 Hz, $575 each when last available) mounted in floor standing transmission line cabinets.  But I added an ambience tweeter (made nice improvements) and a subwoofer (an improvement but not huge). 

[FullRangeMan]

alnico Classic drivers in a 5.6 cubic foot box with a six inch port.
Nice, any photo? Seems a great bass at 157 Liters

[Sarchi]

I think an elegant implementation is a small 4-5 inch dia. driver in a back loaded horn cabinet.  You get wider dispersion from the smaller diameter and lower excursion that doesn't muddy the mids and highs.  Being a horn, the bass is enhanced and the driver doesn't puke above 85dB.  And, the speaker has a small footprint.

A nimble sub can easily make more bass for you.

If you like the lighter side of music, a ported cabinet is a simpler option.

I agree. I recently built the Metronome with the Fostex FE127e (4" FR driver, discontinued). It's not a backloaded horn, it's a tapered pipe...but achieves the same goal. I'm very impressed with the sound quality. I've had FR's from 3" to 8", and minimalist coaxials from 8-15". There is something really special about the smaller FR's, if your design can get some bass out of them. One thing I've learned though, even though these drivers are very easy to drive, they benefit from a little more power - or to be precise, an amp with a decent damping factor/ability to push low impedance loads. The Fostex sounds a lot better with my 30w PP amp than my 300B SET, even though the 300B is a better amp. This has to do with the mechanical control (Qms) of the driver. Now if the driver is low Q, like an 8" Lowther, then a watt or two is all you need - but since that type of driver hardly moves, it needs a big horn to make music. Hope this makes sense.

[FullRangeMan]

The 4/5'' FR drivers will be useful when some manufacturer made a 1 ohms driver to be used serialed in a LineArray to 8 ohms.

My favorite 4'' is this:
http://www.madisoundspeakerstore.com/approx-4-woofers/sb-acoustics-sb12pac25-4-4-aluminum-cone-woofer/#tab-1
Unfortunately SPL is very shy 87dB.

[Sarchi]

 

[FullRangeMan]

This SB is 87dB/4 ohms and the competidor Alpair 10M/8 ohms is 88dB this not alot of sound, good for desktops and needs 20W or more.

[mresseguie]

My apologies for taking so long to reply. I managed to pick a very busy day to ask my question.

Thank you all for your replies. As it happens, the driver I've spent the most time considering is the Classic 12 alnico driver. I'm pretty certain my wife would have a heart attack if I surprised her with the 15" driver in a ported enclosure. Before I began considering the Classic 12, I'd considered a 4" or 5" driver.

Takman,

I remembered that Don had switched to a full range driver, but I'd forgotten who the manufacturer was until you posted. I'd like to learn more about either the 12" or 15" driver - anything you care to add is fine. I think I need to chat with David Dicks, too.

I'll let you all know what I decide.

[OzarkTom]

I am using a pair of Common Sense large box speakers with a pair of 8 inch alnico retired drivers. I cannot find any fault with the bass, they will vibrate the room if there is low enough bass in the source.

[FullRangeMan]

The internal stuffing can increase the bass alot or nothing depend on what material is used.

[JLM]

The laws of physics dictate that if you want all the high frequencies, a large/well defined soundstage, and are OK with limited by moderate sound pressure levels and lack of "real" bass go small (4 - 5 inch diameter drivers).  If you want to feel you pant legs moving with full bass and/or reach higher sound pressure levels but suffer from 'beaming' (narrow dispersion) of high frequencies and  associated tiny soundstage go large (12 - 15 inch diameter drivers).  Anything in between driver size compromises all the above.  Note that many single driver fans have deluded themselves into denying the very existence of deep bass and are actually shocked and/or simply don't like it when they do hear it.

And IMO if you want to consider a driver with a whizzer (secondary smaller cone which acts like a mechanical crossover), then get out of here (no longer a purist single driver) and just look for coaxial designs to gain some of the coherent sound of a single driver.  A better way to 'cheat' those pesky laws of physics might be to use a small driver and add one or more subwoofer(s) that can reach up into mid-bass frequencies (but you'd lose a touch of coherency to gain more bass performance).  Again, there is no perfect speaker. 

Some might say, what about vertical (or curved) arrays?  I'd say mighty expensive if you use good drivers/highly compromised sound quality if you use crummy drivers, plus phase issues with varying distances from each driver to the listener's ear, literally hundreds of feet of wire involved, and again those laws of physics say that they can't image vertically.  All together you're getting a long way from the single driver ideal.  Others have used a pair of drivers: front mounted (losses coherency and is a trade off between no crossover and limited frequency range compared to a 2-way design); dipole (presents the opposite of a single point source ideal so discrete imaging is lost); and bipole (my favorite as it doubles bass output and adds ambience but is still bass limited if using small drivers).

[Dieterle Tool]

^ I don't disagree with any of that, but I would like to add my experience with Audio Nirvana's newer "Classic" series drivers. They do not have a whizzer and remarkably do not have that "shout" typical of most full range drivers. I too (like datman), have the alnico 15" Classics from AN. I built 8.0 cubic foot enclosures for them and bass is pretty damn good. But they are huge and would not be an acceptable solution for a joint purposed living situation. As far as high frequency roll off, most of us can't hear above 12-15 kHz anyway. I personally do not miss the high frequency extension offered by tweeters. Although the "late ceiling splash" concept is brilliant when properly adopted (has little to do with adding HF).

 So I say go big if you have a dedicated listening space and are older than dirt. Otherwise a little compromise should be expected in one or the other frequency extremes.

-Dieter

[FullRangeMan]

I would like to add my experience with Audio Nirvana's newer "Classic" series drivers. They do not have a whizzer and remarkably do not have that "shout" typical of most full range drivers.
My experience with the Classic10Alnico is the same.