Defining the single driver speaker

jrebman · « **on:** 10 Sep 2007, 04:14 pm »

The definition of a single driver speaker, as with most things audio, has several interpretations, so let's try to figure it out between us. Right now there seems to be a consensus building around the idea of a wideband driver handling the bulk of the musical spectrum, which is, or is not augmented with subs and/or supertweeters.

So let's see where this goes...

-- Jim

miklorsmith · « **Reply #1 on:** 10 Sep 2007, 05:01 pm »

My speakers have 7 drivers per side and I demand to be included.

Bob in St. Louis · « **Reply #2 on:** 11 Sep 2007, 01:06 pm »

Quote from: miklorsmith on 10 Sep 2007, 05:01 pm

My speakers have 7 drivers per side and I demand to be included.

I think, based on that comment, you and I are closer to the array forum than this SD forum.

Bob

SET Man · « **Reply #3 on:** 12 Sep 2007, 05:22 am »

Hey!

My definition of Single Driver speaker?

Well, if you are watching you TV right now than you are likely listening to a SD speaker system... of course this is a bad example of SD speaker.

Basically in an ideal world there will be just one driver in each channel that could handle 20Hz to 20KHz and beyond without any xover... hi efficiency is a plus

Of course that doesn't exist.

As for type of drivers. Well, we all know about Lowther and Fostex. But there are other that I would consider them SD speaker. First one and this is probably what many already have... the headphone. Yes, the headphone of which most of them have just one driver and without any xover. Than there is the fullrange electrostatic speaker some like the the Martin Logan CLS.

So, for me it would be at minimum a SD speaker should be able to handle 80hz to 12hzk+ by itself. And one that I feel that would be something that most SD could live with is driver in cab that could handle 40hz to 18hzk+ My current home made seem to cover a little more than that in my room... even without supertweeters

Anyway, there are two SD speaker system that I think came close to an ideal. The Fostex F200A in Brines FTA-2000 cab and Teresonic "Ingenium" with Lowther... from what Scott's review. I've heard the F200A in FTA-200 cabs and I was impressed with the low end of this driver. The down side of the F200A is that they are not efficiency enough for me.

Well, that's how I see it.

Take care,
Buddy

jrebman · « **Reply #4 on:** 17 Sep 2007, 03:37 pm »

So, any further thoughts on the subject?

So far, I think we have the idea that a single driver speaker should be one in which a single, wideband driver is handling the bulk of the musical information, though there is no real consensus on what that means. Some say the standard 80-8000 Hz is the minum, but there are plenty of fine speakers out there that don't even hit that mark, and which would still be considered a true single driver system. The Auditorium 23 Solo Vox comes to mind with it's 100 Hz bottom end.

Should efficiency enter the discussion?

Then there is the question of multiple drivers (of the same type and carrying the same portion of the spectrum) -- i.e. - di/bipoles, OBs with two vertically arrange drivers, etc. While these may not preserve the idea of point source coherence, my feeling is that if they are indeed of the same type and handling the same part of the spectrum, then they should count. I can't think of any reason why the Omega dipoles, for example, wouldn't be considered part of this group.

Then there's the question of crossovers. I am not sure what to say here but my feeling that if there is any crossover at all, it should be of the simplest type, and only for rolling off the top or bottom end to transition well with a sub or supertweeter. BSC and other compensation networks, while they do compromise efficiency seem like a completely reasonable thing to me and not any sort of divergence from the SD genre.

Any other thoughts?

Are we getting closer to a definition, and really, do we even need one, as most folks who are into it are already aware of what they have, and I'm guessing that most of the others don't really care. In other words, if you see a circle called "single driver speakers" and you check it out and post in it, chances are it is something that you know about and what interests you.

-- Jim

michaelavorgna · « **Reply #5 on:** 17 Sep 2007, 03:58 pm »

Hi Jim,

Quote

The Auditorium 23 Solo Vox comes to mind with it's 100 Hz bottom end.

I was wondering where you got this info from? It doesn't jive with my experience as an owner or the published specs for the stock PHY driver.

http://www.phy-hp.com/English/Products/H21lb15_SAG_E.html

And here's a quote from Jules Coleman's review of the SoloVox:

"Output falls off precipitously above 12KHz and there is little output below 40-50Hz."

I'm not trying to start any wars or even suggest I can back up the fact that I hear stuff well into the 40s with scientific evidence, but I'd bet my tweeters the SoloVox go below 100Hz.

Cheers & good luck with the Single Driver Speaker forum. Excellent idea!

jrebman · « **Reply #6 on:** 17 Sep 2007, 04:14 pm »

Michael,

Thanks for the note and for posting here. Mea culpa -- I was basing my comments on that same review by Jules Coleman, and I thought he said that things fell off precipitously at 100 Hz or so. I'll have to go back and re-read it as it's been at least a year or more since I read it.

Hey, if you're looking for another Sony PS-1, drop me a PM.

Thanks,

Jim

michaelavorgna · « **Reply #7 on:** 17 Sep 2007, 04:35 pm »

Jim,

No worries. The single-driver speaker approach seems to suffer from a bunch of misconceptions. Inadequate bass being one of the biggies.

You can find Jules' review here http://www.toneimports.com/reviews.html - the original site where it was published has gone mysteriously missing for about a year.

Oh No! Not the dreaded PS1 topic. I've never had knowledge of this PS1 nor do I know anyone who's commingled with one.

Scott F. · « **Reply #8 on:** 17 Sep 2007, 05:13 pm »

Jim,

Bumping up the low frequency response a bit to 100 or even 150 Hz to cover the definition I think would be fine. Guessing, a fairly large segment of the single driver community probably uses subs to augment the lowest three octaves. Much beyond the 150Hz range then starts to get you into many other designs like front loaded horns like the Oris or even big Altec's.

When it comes to notch filters, the same holds true. Many of the guys use these to tame frequency peaks from the drivers or baffles. When it comes to actual crossovers, my personal preference is for 1st order but that doesn't mean higher order XO's can't sound good either. I don't think these should play into the definition of a single driver speaker.

I'm not sure efficiency should play a factor here. There are a number of lower efficiency drivers that could be considered full range like the Jordan's and Manger drivers.

I'm with you, keep the definition loose and see where we end up. That average guy that sees a Single Driver circle either understands the intent of the circle and likely won't post about his two way speakers that crossover at 1250Hz. Besides, somebody may come across a killer driver that sounds great from 40-6kHz and only costs $30/pr. That could make for an easy and cheap project with loads of discussion.

nathanm · « **Reply #9 on:** 17 Sep 2007, 07:52 pm »

And the Lord spake, saying, 'First shalt thou mount the Holy Driver. Then, shalt thou count to one. No more. No less. One shalt be the number thou shalt count, and the number of the counting shall be one. Two shalt thou not count, neither count thou naught, excepting that thou then proceed to one.'

Single driver speaker: ONE vibrating diaphragm per cabinet, no crossover.
YES:Ed's Horn, Norh 3.0, computer speakers, lowthers, fostex headphones etc.
NO: Zu Druid, Tannoy Coaxials, the above combined with a tweeter etc.

The above combined with add-on tweeters or bass cabinets might be a single driver speaker based system but not a single driver speaker. If there is more than one driver per side it should not be called single. Full-range, extended, wideband, or something else, but just not single. Assuming stereo you could have a pair of single driver speakers and actually have two drivers total but if you've got four drivers in two cabinets don't call one side a single. The true, purist single driver speaker would actually be a mono system but I am not sure how many folks actually have one speaker sitting in the middle of their room.

rajacat · « **Reply #10 on:** 17 Sep 2007, 08:05 pm »

How about crossoverless speakers as more apt description for the circle? Doesn't exactly roll off the tongue so perhaps the circle should retain the same name but include only and all speakers without crossovers in the discussion.

JRace · « **Reply #11 on:** 17 Sep 2007, 09:29 pm »

Single driver speakers can (and some must) have crossover components - mind you this is somewhat of a misnoner as the components are not crossing-over anything....more cleaning up the sound to acheive the desired response. Notch filters, baffle-step-compensation networks, etc...

IMO if the speaker has more than a single driver it cannot be a single driver speaker!

rajacat · « **Reply #12 on:** 17 Sep 2007, 09:51 pm »

Quote from: JRace on 17 Sep 2007, 09:29 pm

Single driver speakers can (and some must) have crossover components - mind you this is somewhat of a misnoner as the components are not crossing-over anything....more cleaning up the sound to acheive the desired response. Notch filters, baffle-step-compensation networks, etc...

IMO if the speaker has more than a single driver it cannot be a single driver speaker!

Yes, you are right crossover components but not true crossovers so therefore SD speakers are crossover-less. Should coaxial speakers be allowed in the definition?

JLM · « **Reply #13 on:** 17 Sep 2007, 10:02 pm »

I'd vote for any speaker with a one driver that goes 60 - 8,000 Hz without a crossover. (I don't consider baffle step or zobel compensation to be a crossover.)

Line arrays, dipoles, bipoles, and Bose 901s go home.

Russell Dawkins · « **Reply #14 on:** 17 Sep 2007, 10:08 pm »

Quote from: nathanm on 17 Sep 2007, 07:52 pm

And the Lord spake, saying, 'First shalt thou mount the Holy Driver. Then, shalt thou count to one. No more. No less. One shalt be the number thou shalt count, and the number of the counting shall be one. Two shalt thou not count, neither count thou naught, excepting that thou then proceed to one.'

Single driver speaker: ONE vibrating diaphragm per cabinet, no crossover.
YES:Ed's Horn, Norh 3.0, computer speakers, lowthers, fostex headphones etc.
NO: Zu Druid, Tannoy Coaxials, the above combined with a tweeter etc.

The above combined with add-on tweeters or bass cabinets might be a single driver speaker based system but not a single driver speaker. If there is more than one driver per side it should not be called single. Full-range, extended, wideband, or something else, but just not single. Assuming stereo you could have a pair of single driver speakers and actually have two drivers total but if you've got four drivers in two cabinets don't call one side a single. The true, purist single driver speaker would actually be a mono system but I am not sure how many folks actually have one speaker sitting in the middle of their room.

Nathan,

I bow down in deference to your authoritative take on thith. I thinketh that it ith abtholutely impothible to mithconthtrue your (or God'th) meaning in thith and, furthermore, that coaxials are an abomination and demonthtrably not thingle yea, even though they be good, on occathion.

Ruthell

rajacat · « **Reply #15 on:** 17 Sep 2007, 10:09 pm »

So coaxial speakers like the Hawthorne Silver Iris would not be discussed in the SD circle? Maybe the single driver definition might be a little too finely and literately drawn.

We couldn't discuss supertweeters either?

rajacat · « **Reply #16 on:** 17 Sep 2007, 10:18 pm »

It doesn't seem logical to allow supertweeters to be discussed because then there would be two drivers per side. The true purist must not fiddle with supertweeters to stay true to the single drive ideal.

nathanm · « **Reply #17 on:** 17 Sep 2007, 10:27 pm »

Thank you Russell. Indeed, I spent many hours in thought upon what could possibly define a single driver speaker. At first it seemed obvious; a single driver speaker is one with three or more drivers! Duh! But eventually this theory gave way to the Quad Theory, wherein at least four drivers were necessary. I then honed this down to the dual driver theory which was working quite well. But then it struck me; what else could a single driver speaker be except one with a single driver!? Eureka! Granted, I could still be wrong; for all I know a single driver speaker could involve potentially hundreds of drivers but right now I am sticking with one.

MJK · « **Reply #18 on:** 18 Sep 2007, 12:33 am »

To the purists,

I think that you guys are making your definitions so tight and restrictive that eventually only 4 or 5 people will qualify to post. As it is right now, I don't qualify but I still consider myself a single driver speaker user and believer. I own 7 pairs of Lowther drivers, 2 pairs of Fostex drivers, 10 pairs of the old Radio Shack 40-1197 drivers and 8 pairs of the old Radio Shack 1286C bought on clearance for a song, and a big old pair of University 15" triaxials. But I also have and use woofers and super tweeters, an electronic crossover, and multiple amps with my full range drivers. So I don't qualify.

I think you have to decide if you want a policy of exclusion or inclusion. I see a policy of exclusion developing. A policy of inclusion might redefine the forum as one where full range drivers are used in speaker systems, sometimes alone and sometimes in combination. Your rigid definition would even exclude bipoles using the same driver, does that make sense? Even if used in combination with other drivers full range drivers are not anywhere near to being a typical two way with a midbass and tweeter or a three way speaker with a woofer, mid, and tweeter. The goal is still the same, no crossover in the critical frequency range.

So if you want to be strict in your interpretation/definition and preach only the purist rhetoric that is fine but your discussions will become limited to a few contributors, narrow, and repetitive. If you want to open your eyes and ears to other applications of these interesting drivers you might see and discuss some things that are beyond you current field of vision. I am not sure what you are afraid of reading or considering by allowing the use of woofers or supertweeters. Work it out and I will post and contribute if I can in line with the rules, or abide by your restrictions and go elsewhere. It is your forum and the majority rules.

Just a thought,

Martin

raov1 · « **Reply #19 on:** 18 Sep 2007, 01:06 am »

Single driver speaker = one man army.