Evolution of Speaker / Electronics Ratio

[Cosmik]

Agree that DSP is a huge help when it comes to crossovers.

But unless you have a Spin-o-rama rig at home you're well short of being able to accurately measure dispersion and also well short of what the best engineered commercial designs offer.

Well I have already taken care of by far the biggest dispersion factor of all: I specified three-way, not two. And for even better performance we could go four-way.

A Spin-o-Rama seems like a very quaint, old fashioned solution to a problem that may, anyway, not be as crucial as people have been led to believe. If we are serious about this sort of thing, we would be simulating the whole thing in software and evolving it using genetic algorithms - as long as we knew what 'target' we were aiming for. But I'll bet that the results wouldn't sound as drastically different as you expect.

Nothing to stop anyone from doing the Kii/Beolab multiple drivers thing, either.

By far the biggest factors in the home constructor's favour are the freedom to eschew 'fashion', and to insist on things like phase/time alignment and the use of large sealed woofers.

 

[watchnerd]

Well I have already taken care of by far the biggest dispersion factor of all: I specified three-way, not two. And for even better performance we could go four-way.

A Spin-o-Rama seems like a very quaint, old fashioned solution to a problem that may, anyway, not be as crucial as people have been led to believe.

Have you read Floyd Toole's research?

Also, Harman tests big speakers on the Spin-o-rama, too. It's not just for little guys.

 

[Cosmik]

Have you read Floyd Toole's research?

Yes... do you find it all that thrilling? I think the conclusion is kind of obvious, and no obstacle was going to get in the way of arriving at it.

Don't give your speakers a weird dispersion pattern. Got it.

 

[watchnerd]

Yes... do you find it all that thrilling? I think the conclusion is kind of obvious, and no obstacle was going to get in the way of arriving at it.

Don't give your speakers a weird dispersion pattern. Got it.

Sorry, but your answer grossly oversimplifies the debate of limited directivity controlled dispersion loudspeakers vs wide dispersion that has been raging for several decades.

It's not simply a "weird dispersion pattern".

The limited directivity controlled dispersion crowd believes room interaction should be tightly controlled. Contrast that with the opposite philosophy of highly regarded bipolar panel radiators like Quad and Magnepan.

So, yeah, there were plenty of obstacles at arriving at the conclusion and it wasn't necessarily obvious.

Anyway, this is getting way off topic for the thread...

 

[fas42]

Weird dispersion doesn't matter, if the quality is there. On another forum a member mentioned another casual, subjective evaluation tool - have someone move around in front of the speakers, walk past them slowly while they're working. This is weird dispersion with a bit of grunt to it - with a competent system that person will be effectively invisible, subjectively the sound won't suddenly collapse into a heap.

 

[watchnerd]

Quality as in it approaches that needed for the speakers to fully disappear, acoustically. The numbers don't exist that measure this, not because it can't be done, but because no-one knows precisely what to measure, me included. It's tied up with signal to noise, dynamic noise modulation, interference rejection - a whole host of things which are swept under the carpet, using the line "competent engineering takes care of this, don't worry your little head about it" ...

Tying it back to the thread....

Can you do this for $600 for the whole system?

 

[fas42]

Yes. There are intelligent, very low cost parts and methods for getting all the requisite competence - personally, I do it by experimenting with low cost, second hand components, using replacement parts, if needed, that are only as good as they need to be, from a normal electronics supplier.

 

[watchnerd]

Yes. There are intelligent, very low cost parts and methods for getting all the requisite competence - personally, I do it by experimenting with low cost, second hand components, using replacement parts, if needed, that are only as good as they need to be, from a normal electronics supplier.

Can you give examples of such components and parts?

 

[Cosmik]

Sorry, but your answer grossly oversimplifies the debate of limited directivity controlled dispersion loudspeakers vs wide dispersion that has been raging for several decades.

It's not simply a "weird dispersion pattern".

The limited directivity controlled dispersion crowd believes room interaction should be tightly controlled. Contrast that with the opposite philosophy of highly regarded bipolar panel radiators like Quad and Magnepan.

So, yeah, there were plenty of obstacles at arriving at the conclusion and it wasn't necessarily obvious.

Anyway, this is getting way off topic for the thread...

I haven't oversimplified anything. You say it yourself: there is a debate about whether to go for (non-weird) wide dispersion versus (non-weird) narrow dispersion, and no one has been declared the winner - not even the revered Floyd Toole. Unless you know of a weird dispersion advocate as well?

B&O have made directionality an adjustable characteristic. Personally, I actually quite like the sound of 'monkey coffins' - active of course.

As I mentioned earlier, if you know the characteristics of the ideal speaker there is no obstacle to programming a computer to create it. It could be a concrete cylinder that goes from floor to ceiling, comprising 100 drivers, or a single flat panel with a thousand separately-driven electrodes. For the prices audiophiles are duped into paying for one piece of wire, these things could be done.

But your comment highlights how would-be 'scientific' audiophiles go round in circles. They talk about measurements and quantifying stuff, but they can't agree what constitutes a good measurement in the first place. Things get confused: the reason why Quads have their legendary status may be that they once produced a more coherent mid range and treble than could be achieved by the crude technology of other speakers of the time - it doesn't mean there is something inherently better in their dispersion characteristics. Nor does it mean that they do anything better than can be achieved by modern techniques in a much more practical way. But the legend persists, and people project onto them whatever their particular interest is.

 

[fas42]

Can you give examples of such components and parts?

As an approach I would use right now, those JBL 3 series speakers sound like they have most things pretty right, out of the box . I would take a pair, see where they fall down, and correct as necessary - keep researching until I've nailed the quality aspects ... and take it from there ...

 

[RayDunzl]

those JBL 3 series speakers sound like they have most things pretty right, out of the box . I would take a pair, see where they fall down, and correct as necessary

Here's something to save you some time.

http://noaudiophile.com/JBL_LSR308/

 

[fas42]

OK, straight away, the construction is too flimsy to be able to carry it off - make a bigger box so that the bass numbers look better - and it all goes downhill. I had the same experience with the older, Behringer equivalents - the bigger brother looked on paper to be significantly better, but in the flesh it wasn't in the race - the smaller one had much better tightness of sound - for the simple reason that the panels are much stiffer; same thickness but smaller area. For those JBLs, you would have to "rescue" the carcase by adroitly bracing it where essential.

 

[fas42]

Reminds me of when I purchased some decently high column speakers many years ago - previewed a few in the quite ordinary electrical area of the store, and some of the "respectable" brands, English and such, started rattling various bits of themselves when the pressure was on. The ones I got were almost unknown, Oz designed, Chinese made - but the carcase had decent guts to it - no Wilsons, but if they dropped on your toes ...

 

[watchnerd]

Nor does it mean that they do anything better than can be achieved by modern techniques in a much more practical way. But the legend persists, and people project onto them whatever their particular interest is.

I've never owned Quads, but I do have a pair of Martin Logans that I hook up for time to time. Electrostatic speakers still have a few advantages:

1. Broad single-driver coverage without the need for a crossover through the critical midrange and above, with perfect phase

2. Fast impulse response due to low moving mass, which also leads to less energy storage

3. Most importantly, distortion stats that are 1-2 orders of magnitude lower than dynamic drivers

They're a complete pain in the ass in other respects, but electrostats are still very hard to beat in some areas.

 

[watchnerd]

Here's something to save you some time.

http://noaudiophile.com/JBL_LSR308/

I own the LSR305 for my home office and actually think they're the better of the two unless you want to mix dance music or rap.

Sound on Sound agrees, giving both the thumbs up, but preferring the 305:

http://www.soundonsound.com/reviews/jbl-lsr305-lsr308

Music Tech felt similarly, giving the 305 9/10 and the 308 8/10:

http://www.musictech.net/2014/03/jbl-lsr-reviews/

The shockingly inexpensive LSR310S subwoofer mates well with both, in my experience, and is pretty good for music for the price. It's still too small for home theater nutters who like to feel their balls quiver from LFE, though.

 

[watchnerd]

carcase had decent guts to it

When you say carcass, are you referring to the cabinet?

Or something different?

 

[fas42]

So, where are the measurements that tell one that the wobbly wood panels are great for adding extra, ummm, zippiness - but not so good for accuracy ...

 

[fas42]

When you say carcass, are you referring to the cabinet?

Or something different?

The cabinet. The other term must have been used quite a bit when I was focusing on reading up on such matters.

 

[fas42]

It's still too small for home theater nutters who like to feel their balls quiver from LFE, though.

This sort of thing completely ruins a movie for me - it's exactly equivalent to the young twits bulging the sheet metal of their ride with a throbbing beat - this is duhhh! stuff ...

 

[Don Hills]

Have you actually built speakers from scratch before?

I have. Getting it to make sounds is easy. Getting it to sound superb is hard and takes a huge amount of time, testing, measuring, re-testing, re-measuring, re-building the box when you decide you prefer a different Q for the bass, etc.

AkAbak and ABEC (and Hornresp) have been available for the home constructor for some time. They can save a lot of time, wasted wood and parts.