The 4345 2010

[Ian Mackenzie]

Thanks at all for the great input!

But the dusted 2425j looks like a smart idea. Would work without crossover changes, except for the level of the l-pads...

Unfortunately your statement above is incorrect.

Please refer to my earlier post.

Neither the response nor the impedance of a dusted diaphragm is suited to the stock network or the equivalent.

As was stated earlier you need to get you hands dirty then you will learn and grow with this hobby. In time you will start to understand how to design a diy loudspeak (There is no other around it.)

In the diy loudspeaker space one persons opinion (which is quite often the case) could be another’s bullshit.

And the measurements don’t necessarily tell you if it works. You need to make things and listen like everyone else.

If you don’t feel that is the road you can build a JBL design as closely as you can and get a good result.

We’ve been over this a thousand time

[Dr.db]

My mistake, I thought the idea was to aquaplas the existing diaphragm. I wasn´t aware of any aquaplased diaphragms readily available for 1"-drivers...

[marco_gea]

In that case, do you guys think the Yuichi A480 is a major upgrade to the original 2307-2308 horn-lens?

YES.

But, only once all the caveats discussed above regarding crossover and overall system integration have been duly considered.

[Ian Mackenzie]

My mistake, I thought the idea was to aquaplas the existing diaphragm. I wasn´t aware of any aquaplased diaphragms readily available for 1"-drivers...

They are only available now for large formal Jbl compression drivers.

Jbl only did acquaplas 1 inch diaphragms for the 275nd used in several systems in the1990’s.

The only other 1 inch aquaplas diaphragm are diy attempts about 10 years ago.

But my point as described early is under scrutinised measurements the diy acquaplas diaphragm response is different from the stock diaphragm and requires a modified network.

Does this matter? If you are just interested in swapping diaphragm on face value at home then No.
The same applies to any matter of horns.

BUT, if you are an audiophile and serious diy amatuer then making changes and getting then to work properly requires a disciplined approach, the right tools and significant understanding of what really matters and how things work.

I am an staunch advocate of the latter because it’s a waste of time otherwise if you are serious about audio reproduction.

Please read the commentary by this widely respected diy loudspeaker designer for an illustrated guide to how to succeed. The article also provides insights into the unique qualities of well executed four way system.

My own experience and investigations over the past 20 years indicates the drivers were and still are under utilised in these systems and with associated components. Meaning everything matters.

My unqualified advice is before you change anything buy or build the best the best amps you can afford for the mid, horn and uhf.

http://www.troelsgravesen.dk/The-Loudspeaker.htm

[Robh3606]

But my point as described early is under scrutinised measurements the diy acquaplas diaphragm response is different from the stock diaphragm and requires a modified network.

That certainly was the case with the dusted 2435's. Even if you don't dust them you need to run impedance and frequency response plots on the drivers to make sure you have the diaphragms properly re-installed.

Rob

[Dr.db]

Thanks for the link, very nice to read.

Regarding the diy-game, I get you.