AL170 and G25FFL in bass reflex box

[walwal]

If the baffle meters 20 cm and has 3 cm chamfers, the sonogram is real good. Ib you don't like the design, try, what ist the best compromise between design and function.

[mcl2k6]

Thanks!
Indeed, the energy FR had a more pronounced negative slope on my original design compared to your optimizations.
Maybe I will give it one more try, although the current all-2nd-order one is comparable.
Making changes to the baffle is currently not an option. My wife told me to finish first the current set, before going on another crazy new project with lots of sawing and tinkering

You know, Boxsim contents a Tool "optimize"?

I did this, here the result. First of all, your crossover ist very good. But, if the Energiefrequenzgang has a slope, the Box sounds too dull, therefore you should lift the frequencyresponse a little bit like the optimizer did.

My advice: look for available values for the crossover and check the simulation again. 1500 Hz ist ok for the G 25 FFL in WG. A liitle bit better will be the KE25, but more expensive.

If you look for Sonogramm, you will see at 2-3 kHz some disturbances. The reason ist Bafflediffraction. whith a smaller one it will be better. You can read also here. Good luck.

https://heissmann-acoustics.de/kante...eiberanordnun/

[walwal]

Your box is tuned to 37 Hz, i guess, 30 would fit better to most rooms. But this is trial and error, so keep the reflexport variable in length.

[mcl2k6]

I have the feeling that the box is on the limit of what's recommended for the AL170. It's around 37L, so that low tuning might not work efficiently already.

Your box is tuned to 37 Hz, i guess, 30 would fit better to most rooms. But this is trial and error, so keep the reflexport variable in length.

[UweG]

I'm a bit confused about the discussion. I understood that this speaker is built already and that the measurements and the project file that was posted in #11 is the current state.
Did I understand right?

[mcl2k6]

It was built already. However, minor tweaks are possible, therefore we're discussing.

I'm a bit confused about the discussion. I understood that this speaker is built already and that the measurements and the project file that was posted in #11 is the current state.
Did I understand right?

[UweG]

Having another look at the project posted in #13 and in the measurements as well, I feel that the microphone was placed higher than the boxes. In this case, the directivity is not fitting due to wrong phase difference.

It should work better with two small mods only needing a new 33 Ohm resistor. You may try 22 ohm alternatively.

[mcl2k6]

Thanks for the suggestion.
I place the microphone to point exactly on the space between the tweeter and the woofer. This is what I have read on several "how to measure speakers" threads and documents.
The distance between the mike and the speaker is ~96cm.
Obviously, there are measurement errors because I do this in my living room, which is about 5m x 4.5 m x 2.5m tall. Around 10% filled with furniture, and some 2m x 1.5m carpet.
The speaker is put on a 0.5m tall table, on the carpet.
Can't do better than this, as I live in a flat, and there is no bigger open space.

Having another look at the project posted in #13 and in the measurements as well, I feel that the microphone was placed higher than the boxes. In this case, the directivity is not fitting due to wrong phase difference.

It should work better with two small mods only needing a new 33 Ohm resistor. You may try 22 ohm alternatively.

[UweG]

In case this is also your normal hearing position, it's o.k. … apart from the unknown reason for the high level around 5k … maybe due to some reflections in the measurement setup?

In case your normal hearing position is e.g. 15 or 20 degree higher than on axis, the current crossover produces a dip (see vertical directivity plot) directly to the listener. That can be avoided or at least reduced significantly by the mod in #22.