new living voice prototype horns

'Isobarik' only works (at all) if the separation between the woofers is insignificant compared to the wavelengths in operation.

The 'sound starts' when the woofer moves, you are asserting in effect that it starts sometime before the outer woofer moves, which is unlikely. Either 'Clio' is wrong or there's something else going on. Perhaps you're measuring at frequencies outside the woofer's design spec?

Obviously the analogy to a horn is unhelpful since the mouth of a horn isn't a driven diaphragm.

Paul

 

You mean one for the rear woofer alone, one for the front woofer alone and one for both woofers?

The only thing I can see is the the woofers start at different times (traveling time to the mic) for all combinations. Hence the acoustical center when both woofer are in function is in between them.
This is what I can meassure.

Say if we have an acoustical phase aligned one piston 3 way speaker. All drivers has the same phase shift at all frequencies. Works like one piston. We have a flat amplitude then as it summarise perfectly at the x-over points.
If we assume we have that, then pulling or pushing one of the drivers back or forth and thereby bring it out of timealignment physically, we would see a dip appear on the total frequency plot.
If I pull out my Orpeans to align the front woofer I see a dip. If I set it aligned with the rear woofer I see a dip.

Hence the acoustical center in the ISOBARIK bass is in the mittle in between the drivers.

Wouldn't you say so?




Gerner

 

If the acoustic output of the two drivers is summed, would that not mean the efficiency would be increased? The efficiency of an Isobaric group is actually decreased.

 

Paul you're absolutely right about the horm mouth not being the acoustical center. But some people think that. Look at all those designs with horns hoping for alignment by placing the mouth aligned with the woofer. Oooops.

My finding is related to the fact that the rear woofer is farer away, it has an acoustical center and that acoustical center plays a role too. I don't refer to that it should start later than the front woofer. But as we have traveling time from the radiant to our ears and one radiant is farer away, it will arrive later.
So my parralel connected woofers, one behind the other, sealed with an airtight tube between them, seems to me to handshake about where the common average source is placed in the time domain.

Clio confirms, my tape meassure confirms what Clio tells and my phase out tests says the same.

Am I in a culprit here or??

I have Googled my self to death on this phenomenon and nobody address the acoustical center for an ISOBARIK the way it's made in my speakers. I cannot find it. Neither what I claim can be Googled without it leads to this thread.


Gerner

 

As I mentioned earlier, the horizontal displacement between the voice coils of the cone and compression driver should be even multiples of one half the wavelength of the transition frequency to maintain proper acoustical phasing.

That will often mean that the horn mouth and bass driver being aligned is perfectly acceptable according to most research.

 

Hi Mic

They are conncted in parallel and in push/push-pul/pul config. They don't sumarise anything inside the cylinder enclosing them. There is only some volume of air that are moved back and forth in absolute phase with the woofers.

Maybe it's a good idea not to call what I have here ISOBARIK, because this is normally defined as two driver mounted face to face in a panel and with reversed polarity on one of the woofers. There you loose 3 db. I neither loose or win gain here compared to the use of only one woofer. But the gain is of course affected due to the amp sees only half the impedance with two woffers.

What I gain is that I can use a smaller cabinet. (Vas related)

Gerner

 

That is correct Mic. Only problem here is the traveling time incoherency.

Lets go to an extreem:

Take a long basshorn, say 10 meters, mouthing out on your wall. Yeah it came from the next room or even the garden.
Then it should match another speaker driver in a cabinet or horn placed in your listening room.

No matter how much you swift phase and polarity, you hear the horn bass arriving too late. And people have to grab for a Behringer thing to delay the room placed speakers. Pfew...
But you address it your self that your trick only works within a certain context.

If we are looking for a one pistion multiway speaker, we have a "fullrange" driver in a way where sound emits from the same vertical point.
The one piston is gone the moment you start to disalign the drivers.

Gerner

 

Isobarik is a Linn trademark. What you have is isobaric loading. This can either be cone to magnet in phase or magnet to magnet/cone to cone with reverse phase. If you have two radiating surfaces producing sound, the increase in output/efficiency is 3db ignoring any mutual coupling that might take place. In this instance you do not gain in efficiency, only in controlling the cabinet pressures and reducing the necessary cabinet volume. Does this not possibly suggest that the acoustic output of the rear drive unit is effectively inaudible?

 

Right on spot Mic. Cone to magnet. This is what I have. And this is what I gain. Just as you say.

Yes the rear driver is "audible" in a way. As well as the outer driver certainly is. It is just not timealigned. And the lack of this underlines what I mean by audible.
But I know what you mean by inaudible.

And all my arguments leaves me in the corner where I cannot figure out why they should not summarise in the time domain as a point in between them.


Gerner

 

i think this is the key point : is the back woofer audible ore not ? if it is, Gerner might be right, but if only the front woofer is audible, then probably only the front woofer is relevant. However, what i remember reading at Bert's Forum , is that in Isobaric configuration the woofer sounds faster and tighter, is this not true ? if advantage is only to get a smaller cabinet, then i dont think its worth to do such a big effort and investment.

Angelo

 

Hi Angelo


I can disconnect the front woofer. You will for sure hear the rear one.

I missed that part on Bert's forum Angelo. To me they don't add any speed, just the smaller cab. advantage...and that is only a visual important thing related to the looks of the Swings.

I had many fine inputs here, which made me ponder again. But that science prevents me until now not to have moved that much toward it could be different.

Gerner

 

My Goodness

This post comes in a off topic inapropriate place, but some how it belongs here.

I just want to clean up my own record here, better do it now than too late.

So guys here it comes:

Naively I jumped on this forum without any recearch done prior to that. I spent an hour or was it two just to come through the posts in this thread to the point I jumped on the train.

I jumped on without knowing what I was doing. Now I somehow know that I shouldn't have, maybe?

I started a Swing topic which where closed after few hours because of personal harrasments by people who jumped on this taxi to Nirvana.

By reading this thread from post one to this, for the moment, last one, I learn that this thread is even worse than the thread/topic I started.

Most schocking was to find Romy alowed to post. Is the moderater a humorist here or is he passed away without no one noticing it?

Next I find others like Romy and in between quite a few serious persons with an honest platform to think out loud.
I was deluted into it by my own lazyness to sign for the seriousity that by first glance appeared. And now I find out that this BS is terrible.

I came in to share what a really decent person as Gordan addressed. And don't spit on him now, I know him better than most of you I think.

I see it's hard for many not to join the same boxing ring that Romy makes his blueprints for: A fight about abslutely nonsense. There is no scientific proves for subjective obeservations and I did not learn as Mic also stated, one thing reading all those posts. Not one thing.
No one seems to have much maths to envelope their posts in. It is one eternal argue about unproved statements delivered by mostly people who did not do any real recearch TMB. Including you Romy. You stole everything from others and just put a system there to defend your choise. Was it really nessecary to make a homepage for that. I mean, we all could do that. Buy a system and defend it.
I find the most empty statements in your post rather than the reactions to them.
Yes I saw your site.
Each an everytime you appear you ask everyone else to disapppear. That's why you have your own forum pal. Only there you can excist.

I kindly ask the moderator of this forum to delete the whole topic and please delete my own topic too. I can only ask because any newbie will think that ZG is a club for lunatics. And if Googeling psycopatic it should appear on the top hit list there.

Now a deep appology to all who contributed to this, beside that OK, forum, it is not your fault. But you are much bettered not having this thread on you site.

I assume some kick backs on my post here will appear. But I will not see this.

I hope you will recover this place as it is much more interesting and encurraging to deal with other forums that doesn'nt contain anything but learning from each others trials and error.

Bey bey....

Gerner

If you beleive that serious audio developers jumps in and takes the gloves on here, your might be very wrong.

I am not even commercial trapped to anyone, neither I have any interest being a teacher ss too many appears to be. I am just me.

It is a crual and very ignorant thread I jumped too.

 

Romy....

hello Gerner

Romy does not post here for some time, probably even not reads the thread here anymore . So why bother abought him ?

rds Angelo

 

Yes you will. Because the front woofer is not moving . If the front moves - the pressure in the gap between the drive units remains constant. If the air pressure is constant, how can that produce sound?

 

I think that assumption only holds if the gap between the woofers is small in relation to the wavelength of the sound. Which it should be.

I wonder what Gerner is measuring and hearing? It's a shame he's gone off in a huff.

Paul

 

FWIW Tannoy treat the point midway down the voicecoils as the acoustic center.
Which at first you may think is no different-but bass drivers tend to have much longer voice coils than HF units.

 

how's possible these horns - based on TAD drivers - are so cheap:

http://www.classicaudiorepro.com/page5.html

prices:

http://www.classicaudiorepro.com/page9.html

 

Those aren't prices. They are the costs of the components that go into each loudspeaker. The Classics are not that great from what friends tell me - the passive crossover is most likely to blame.

 

I've heard them a couple of times & they were fierce each time. Whether it was the crossover design, I couldn't say. It needn't necessarily be the cause. I suspect as often seems to happen, they perhaps believed the TAD spec & were just running them too high.

 

wow,

check out the new definitive audio and living voice websites.

I think they've ''raised the bar'' a bit, compared with many hifi related websites. Nice job.

You get some sneaky peaks at what might be the new design of Living Voice Horns too!




www.livingvoice.co.uk

www.definitiveaudio.co.uk