4-way speaker

I´m thinking of a new 4-way speaker and would like to hear your thoughts about the concept.

My ideas are inspired by the JBL 4355, but I would use some different components. Further more, I would use a different baffle-layout, inspired by the Westlake Audio HR-1.
http://www.westlakeaudio.com/Speaker...ries/hr-1.html

I would use the following components:
- 2405
- 2441 on westlake-horn (2397)
- 2123
- LE14H-1 (2 per box)

- 3155 passive network
- active crossover at 350hz

This is what these speakers would look like:

Attachment 82629

What do you guys think of this baffle-layout :confused:
I´m not shure if 8" between the westlake-horn and 2123 is enough to avoid reflections?
Looking at the pictures of the Westlake Audio HR-1 the distance should be aprox. 8"... But I can´t tell for shure...

The 2405 is positioned right between the westlake-horn and 2123. So the 2405 is 2" below the westlake-horn. Is this distance enough or will this cause reflections?
Different Westlake models using the 2403 below the mid-horn mount these rather close to the mid-horn...

The center of the mid-horn is positioned at my ear-level e.g. the listening-high.
Or should the listening-high be between the westlake-horn and 2123?

Best regards,
Olaf

Quote:

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Originally Posted by Dr.db

I´m thinking of a new 4-way speaker and would like to hear your thoughts about the concept.

My ideas are inspired by the JBL 4355, but I would use some different components. Further more, I would use a different baffle-layout, inspired by the Westlake Audio HR-1.
http://www.westlakeaudio.com/Speaker...ries/hr-1.html

I would use the following components:
- 2405
- 2441 on westlake-horn (2397)
- 2123
- LE14H-1 (2 per box)

- 3155 passive network
- active crossover at 350hz

This is what these speakers would look like:

Attachment 82629

What do you guys think of this baffle-layout :confused:
I´m not shure if 8" between the westlake-horn and 2123 is enough to avoid reflections?
Looking at the pictures of the Westlake Audio HR-1 the distance should be aprox. 8"... But I can´t tell for shure...

The 2405 is positioned right between the westlake-horn and 2123. So the 2405 is 2" below the westlake-horn. Is this distance enough or will this cause reflections?
Different Westlake models using the 2403 below the mid-horn mount these rather close to the mid-horn...

The center of the mid-horn is positioned at my ear-level e.g. the listening-high.
Or should the listening-high be between the westlake-horn and 2123?

Best regards,
Olaf

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Very good,why not 2403?

Because I own 2405 allready and the 3155 network is designed for these.

Quote:

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Originally Posted by Dr.db

I´m thinking of a new 4-way speaker and would like to hear your thoughts about the concept.

My ideas are inspired by the JBL 4355, but I would use some different components. Further more, I would use a different baffle-layout, inspired by the Westlake Audio HR-1.
http://www.westlakeaudio.com/Speaker...ries/hr-1.html

I would use the following components:
- 2405
- 2441 on westlake-horn (2397)
- 2123
- LE14H-1 (2 per box)

- 3155 passive network
- active crossover at 350hz

This is what these speakers would look like:

Attachment 82629

What do you guys think of this baffle-layout :confused:
I´m not shure if 8" between the westlake-horn and 2123 is enough to avoid reflections?
Looking at the pictures of the Westlake Audio HR-1 the distance should be aprox. 8"... But I can´t tell for shure...

The 2405 is positioned right between the westlake-horn and 2123. So the 2405 is 2" below the westlake-horn. Is this distance enough or will this cause reflections?
Different Westlake models using the 2403 below the mid-horn mount these rather close to the mid-horn...

The center of the mid-horn is positioned at my ear-level e.g. the listening-high.
Or should the listening-high be between the westlake-horn and 2123?

Best regards,
Olaf

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The listening height is subject to the vertical dispersion of the 2397 at the crossover point to the 2405 ie 8000 hertz.

The 2405 has quite narrow vertical dispersion.

You will need to experiment with the position of the horn and 2405 yourself. No one can answer this question for you.

As to the location of the 2123 it is likely far enough from the horn.
To work best the crossover should be setup so the design point is at listening height.
The de facto design point is often on axis with the Hf device.

The 2123 is tight between the LE14’s.
Have you thought out how you will construct the sub enclosure for the 2123?
Baffle strength could be an issue and coupling of the LE14’s.

I would prefer you lower the LE14’s so they are under the 2123 and closer together.

The 2123 sub enclosure can then appropriately dimensioned. You will find placing the horn/drivers in its own enclosure a distinct advantage.

1. Independent lateral movement to optimise the crossover design
2. Sealing an air tight enclosure for the 2397 if occupying the woofer enclosure could prove problematic.

I see the key challenge(s) as finding a suitable baffle layout to optimise the design acoustically that can be built without too many construction difficulties.

Again you SHOULD make a few prototypes and then listen and measure like real designers do.

Quote:

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Originally Posted by Ian Mackenzie

The 2123 is tight between the LE14’s.
Have you thought out how you will construct the sub enclosure for the 2123?
Baffle strength could be an issue and coupling of the LE14’s.

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You are right, they are very close.
The sub enclosure will be made of 3/4" plywood. So the distance between the LE14´s and 2123 is aprox. 1"... The baffle itself will be at least 2" thick, so the overal strength shouldn´t be an issue.
But I´m not shure if there´s a problem when the woofers are stuffed tightly in an enclosure?
The sidewalls are very very close to the woofers...

Quote:

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Originally Posted by Ian Mackenzie

Baffle strength could be an issue and coupling of the LE14’s.
I would prefer you lower the LE14’s so they are under the 2123 and closer together.

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I have choosen this baffle-layout on purpose, because I wanted to get the LE-14´s as far of the ground as possible.
In a usual setup with the woofers at the bottom, many peoble report problems with the bass-response caused by the room-acoustics. Getting the woofers of the ground should reduce the modal room-resonances...

Getting the LE14´s under the 2123 and closer together will gain their acoustic coupling, that´s correct. But is this as important as reducing the boominess of the room-acoustics?

Quote:

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Originally Posted by Ian Mackenzie

You will find placing the horn/drivers in its own enclosure a distinct advantage.
1. Independent lateral movement to optimise the crossover design
2. Sealing an air tight enclosure for the 2397 if occupying the woofer enclosure could prove problematic.

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I will do this for the prototypes, but at the end I want just one enclosure because of the looks ;)
Sealing the horn air tight could be an issue, that´s a good point! I will work something up, thanks for indicating.

.

Both the 2405 and 2397 have narrow vertical dispersion, so I´m doubtful if a vertical baffle-layout makes sense at all. I can only put one of these devices at ear level... At the moment I havn´t got any 2397 around for a test setup, but I will try this as soon as I get my hands on a 2397.

Quote:

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Originally Posted by Ian Mackenzie

To work best the crossover should be setup so the design point is at listening height.

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Could you please say this with different words, I don´t understand your statement.

Quote:

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Could you please say this with different words, I don´t understand your statement.

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If you were making a smaller 2 way system it would normally be on stands with the tweeter at the height of your ears in a seated position. You would take your measurements on the tweeters axis as an example. With your larger system you need to decide where you listening axis will be. My 4344's were all measured with the speakers on stands using the 2405 and 2307 as the listening axis. When seated with the stands they are right at my ears seated height above the floor. Hope this helps.

Rob

My suggestion is to not overly engineer or pre conceive the concept baffle unlit such time as you have all the components.

Otherwise you will make too many intuitive assumptions.

Questions that come to mind are how is the 2123 going to behave (and sound) directly between the woofers (and how will the woofers react)

The simple answer is you don’t know so you need to consider making up some modular enclosures and stack them in different ways until you get the best results both subjective and measured.

Drivers and how they behave can be very unpredictable. See Troels article and measurements of placement of 10 inch mid drivers on a baffle. If there is a problem how are you going to fix it?

Another problem can be unpredictable enclosure resonances. Woofers in particular can excite complex resonance modes that can be very difficult to control or remove. So again it a case of using the modular approach to refine your concept into a working design.

About room boundaries on bass again its trial and error and listening to see what really works and more importantly what the best compromise.

I would invest in something like SoundEasy and Clio so you can get some worthwhile measurements.

@ROB:
Thanks, I got it ;)

In a westlake-like baffle-layout as I have pictured, where would you see the best listening-axis? Right between the 2397 and 2405, as you can´t have them both at ear level at the same time?
Or should the listening-axis be placed right at the 2397?

@Ian:
I´m aware that I have to do some practical testing when I got all the components, but I want to get to know if my idea is complete nonsense or basically a good concept.

What could be the problem with the 2123 between the woofers?
Westlake has the midcone between the woofers as well, so I thought it should work well.

Enclosure resonances is once again a useful indication, thanks!
I have to adress this topic for shure, but I think it would be too much for this specific thread.

Quote:

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Originally Posted by Dr.db

@ROB:
Thanks, I got it ;)

In a westlake-like baffle-layout as I have pictured, where would you see the best listening-axis? Right between the 2397 and 2405, as you can´t have them both at ear level at the same time?
Or should the listening-axis be placed right at the 2397?

@Ian:
I´m aware that I have to do some practical testing when I got all the components, but I want to get to know if my idea is complete nonsense or basically a good concept.

What could be the problem with the 2123 between the woofers?
Westlake has the midcone between the woofers as well, so I thought it should work well.

Enclosure resonances is once again a useful indication, thanks!
I have to adress this topic for shure, but I think it would be too much for this specific thread.

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Hi Olaf,

In some ways l think you are answering your own questions with your responses.

Obviously if Westlake adopted the general layout its hardly nonsense and you already know that.

What you are doing here is attempting to seek out answers to detailed concerns or doubts you obviously have as to whether it’s is will work satisfactorily before you go ahead?

Your concept is similar in a general sense to some of the Westlake layouts but not in detail if you look closely.
With this sort of thing the devil is always in the detail which you are completely oblivious to.


Your diy project is one of a kind and what one persons way of doing it may not necessarily meet with your approval on a practical level or subjectively.

This is why we are saying you need to start doing your own homework yourself.

That way you will get it.

I don’t have time to elaborate on your questions but if you look at the link the mid cone is not dead centre between the woofers at all in the Westlake systems as you have done. Jbl didn’t adopt that approach with the 4350 either.

http://www.westlakeaudio.com/Speaker.../hifiBroch.pdf

The placement of the mid cone on the baffle is quite sensitive in terms of response variations. Troels illustrates this in his article.

If you do research on these Westlake systems they are not just a bunch of drivers thrown together with a cool looking baffle layout. They are very carefully optimised. The enclosure construction is quite unique as are the crossover networks.

Hi Ian,

thanks for your kind words.
I know I have to do my own homework and promised I will. Please understand my questions more as a consultation with you guys, to secure my understandings of the westlake baffle-layout are correct.

Did I get you right, that the common way would be to have the 2397 at ear level or the 2405?

To me the westlake-style looks like the best baffle-layout for a 2123, 2397 and 2405 I can think of. And I really admire Westlake Audio for their sophisticated work. But there designs are nearly 30 years old, maybe there are smarter alternatives around these days?

I had a look at "Troels" baffle-measurements and understand want you mean. The influence of the baffle-dimension e.g. placement of the 2123 is unpredictable and their is no way around measurements. I agree!

I just had a look at your link (westlake-brochure) and indeed the mid cone is not dead centre between the woofers in the upright HR-1VF.
But have a look at the horizontal format HR-1 here: http://www.westlakeaudio.com/Speaker...ries/hr-1.html