New shelf box with AL170 and G25FFL (_WG)

[Willy_65]

Hello,
I'm designing a new shelf box with the AL170 and G25FFL, with or without waveguide. I would prefer to use the _WG because of the better distribution of the sound.
But in another topic the nasty behavior of the waveguide has already been discussed, in particular the deep dip around 15 kHz.
I always come across these simulations and I find that unacceptable.
Is there a solution for that problem in the meantime? Addition of a rubber ring is not a solution. Visaton must be able to provide a waveguide that is perfect and otherwise no waveguide.

For my boxes it is also important that they can be used optimally for tube amplifiers, so the impedance is much more important than with solid-state amplifiers. This makes the crossover a bit more complicated due to the added resonance filters.

In the following simulations you can see what my results are for a box of H46 - D35 - W25 cm.
The first is without and the second with waveguide.

[walwal]

http://forum.visaton.de/showthread.php?t=30267

The G 25 + WG is not perfect, but this Dip is not so bad, i don't think, you van hear ist. But really bad is the radiation of sound without WG.
The Box with WG therefore will sound much better. Even better will be the Ke 25 + WG.

[sayrum]

Hey Willi

Merry X-Mas!

I think it is great that you are dropping in here, welcome

Are you set on the AL170?
As far as I remember it has a strong resonance which makes it not ideal for a regular 2 way system...

Best regards,
Daniel

[walwal]

The resonance can be taimed by crossing over at 1500 and a Cap + resistor. As shown here: http://forum.visaton.de/showthread.php?t=30267

[Willy_65]

The resonance can be taimed by crossing over at 1500 and a Cap + resistor. As shown here: http://forum.visaton.de/showthread.php?t=30267

That is definitely a handsome and very efficient modification around the 0.82mH.
I had already added that coil to dampen the higher elevations, but it was not enough.
Now it's much better, thanks!

P.S. Crossing over at 1500, is that not to low for the G25+WG?

[Willy_65]

http://forum.visaton.de/showthread.php?t=30267

The G 25 + WG is not perfect, but this Dip is not so bad, i don't think, you van hear ist. But really bad is the radiation of sound without WG.
The Box with WG therefore will sound much better. Even better will be the Ke 25 + WG.

When I read all this, using the _WG is by far the best choice.
The dip around 15 kHz would therefore hardly be heard (except for member "Q").
Of course, it is also true that many designs use the _WG, both for the G25 and KE25.
However, the KE25 is not an option for me, I think it is far beyond budget.

[Willy_65]

A few thoughts about the box itself.
1. I am in favor of placing the bass reflex tube (BR 19.24) at the front since it would strengthen the bass, correct? If not, is there a certain preference for placement on the rear wall?
2. I place the WG as close as possible to the AL170, because that would benefit a better spatial sound reproduction.
Correct or nonsense?
3. The chamfers are not shown in the box here because I'm not a specialist in CorelDRAW. But they will come there in reality: 1.8 cm on the sides.

[walwal]

placement on the rear wall is better due to midrange-mud out of the port.

I place the WG as close as possible to the AL170 correct, if you want, cut out the WG like this:
http://forum.visaton.de/attachment.p...5&d=1505748850

chamfers The more, the better due spatial sound reproduction.

https://heissmann-acoustics.de/kante...eiberanordnun/
http://forum.visaton.de/attachment.p...5&d=1323782386

[Willy_65]

I have repeated the simulation a number of times and I finally have results based on the structure of the Couplet. Special attention was paid to the whims of the AL speakers there.

Merry X-Mas for everyone!

[jama]

simu as shelf and korrekt box
------ free
_______ shelf

[Willy_65]

Good morning jama,

Wow that looks much better!
Apparently I still have a lot to learn, so you removed the AL170 from the "common outer housing" and configured it specifically under "baffle and position".
Frankly, I had no idea how to configure this separately. Can you give me a little explanation of where you get those settings from?

It certainly meets my highest expectations regarding the bass. I think it is very important that with silent background music, the bass is still audibly present, so not like cheap alternatives.
You have more than achieved this here!

update:
I think I get it a bit, the values specific to the speaker are already there and furthermore you have placed the bass reflex back on the front and finally checked out "bottom" and "left" under "diffraction on baffle".
Personally, I would leave "left" checked, because I think that is closer to reality.

Am I correct?
Or should I approach it this way: you are never both left and right of the same box?

[jama]

Hi Willy

is OK so ?


do you have a picture of the shelf where the speakers will be ?

[Willy_65]

Now I understand, apparently not well awake this morning ...
So of course it's about the chamfers: I only have left and right chamfers of 1.8 cm, so we only check them.

You will find a drawing of the box a few posts earlier (black box), with the dimensions.

[walwal]

.... or you switch off the diffraction calculation from the drivers, then boxsim simulates the bass and fundamental tone increase with "wall installation".

...... Where to turn off the diffraction calculation. I didn't find it or didn't recognize it.

you have to do this individually for each chassis under "chassis and installation" --- select chassis and then on "baffle and position" --- deactivate the common outer housing, deactivate the diffraction calculation at the bottom right-hand corner ...

If the Box ist not free standing, the frequency response from 20 - 500 Hz will be increased.
You can calculate this as written above, but this ist not the reality. The best way ist to measure the frequncy respose ald correct this with EQ.

If you listen with low volume, your hearing felts bass too quit. Not the box is wrong, thats mother nature.

Some amplifiers can correct this loudness-effect.

Once again, the chamfers should be as large as possible, those left and right are much more important. The best way is, to make the chamfer as near to the Waveguide as possible.

Here an example



You can calculate this (approximately) like this one:

[jama]

instead of using chamfers in all cases, we can also use the bafflestep-effect to linearize the response curve...