audio-talk

Hi Petr,
If you want to place these speakers hard up against a wall, there is nothing stopping you fitting the port on the front baffle of these speakers instead of the rear as shown. Therefore you can keep everything as designed including the XO filter. *Filter is by request only as certain conditions apply that you have to agree to before a copy will be sent to you direct via email.

I only had the port tube on the rear so as not to spoil the looks of the nice clean front baffle.

Hello Toppsy, thank you for your reply. The speakers will not be hard on the wall, but like 20 cm from the wall. Would it be enough? If not, can the port be positioned higher on the front baffle?

The height of the port is important (this design relies on how sound bounces from top-to-bottom), but it can be on the front or back or either side.

Chris

As Colin and Chris note, being a quarter-wave design, the vertical position of the vent from the internal base of the enclosure needs to be maintained, although it can be relocated to the front or sides if you prefer. At c. 8in from the front wall, I wouldn't anticipate any issues with the rear vent location though; like almost all my enclosure designs it's a lightly damped alignment rather than flat or peaking, so is quite flexible when it comes to room positioning.

Re sealed boxes, this is a pro-audio coaxial, so Fs is relatively high, and Qt relatively low, making it unsuited to sealed box loading (even with boundary gain), and not much cop with regular vented boxes either if you want any usable LF output. That's why I went with the QW load.

Thank you Scott for advice, I would keep the project with rear port. I emailed Toppsy, I am really curious how the crossover looks like. Kind regards, Petr

petr.kosin wrote: ↑Fri Dec 06, 2019 2:27 pm Hello Toppsy, thank you for your reply. The speakers will not be hard on the wall, but like 20 cm from the wall. Would it be enough? If not, can the port be positioned higher on the front baffle?

I have mine toed in slightly, 23cm inner corner and 26cm outer corner from a wall, and they sound great.

petr.kosin wrote: ↑Sat Dec 07, 2019 5:38 am Thank you Scott for advice, I would keep the project with rear port. I emailed Toppsy, I am really curious how the crossover looks like. Kind regards, Petr

Petr,
you have email reply.

Toppsy wrote: ↑Sat Dec 07, 2019 10:24 am

petr.kosin wrote: ↑Sat Dec 07, 2019 5:38 am Thank you Scott for advice, I would keep the project with rear port. I emailed Toppsy, I am really curious how the crossover looks like. Kind regards, Petr

Petr,
you have email reply.

Thank you all, I will post the build progress

Hello,

so hopefully I have everything needed for the build. Wood material is steamed beech wood, 20 mm boards, glued with frequent use of biscuit joints.
I have a question on the length of the port tube. When there is 35 mm in the project, is it meant 35 mm from the outside of the box, or 35 mm inside the box (therefore 35 + 20 mm thickness of the wall = 55 mm port)? I am attaching first pictures of the build.
Thanks a lot, Petr

Petr,
Looking good. As we say on this forum Shoddy. Which means very nice mate.

I have a question on the length of the port tube. When there is 35 mm in the project, is it meant 35 mm from the outside of the box, or 35 mm inside the box (therefore 35 + 20 mm thickness of the wall = 55 mm port)?

Port tube length is 35mm total, measured from outside of the box.

Hello,

project finished, thank you very much for all help. Speakers sound heavenly compared to our old Magnats. All spectrum is clear, no rumble or mumble. Proof is my wife never turned volume down since I’d connected them. When I connected old Magnat on one side and this Monacor on the other for a while, the old side was just booming and from the Monacor side Gregory Porter literally visited us home.
Sufrace finish is just waxed pure wood and I changed the frame grill (so magnets are useless) to PA grid, because we really like the octagonal shape of the Monacors. I also added stand with built-in 6 kg iron ingot to move down the center of gravity, the final weight of one speaker is around 20 kg.

Thank you again,
Cheers,
Petr

...and some more pictures...

Those are very nice..

Top job there Petr they look really nice indeed. Your workmanship is first rate.
The sound will improve as the drivers free up.
You may find it worth while lifting the front of the speakers by say 6mm, so they are angled backwards. It's how I have built mine and the couple other pairs I have made for fellow forum members. This should aim the compression tweeter firing more towards ear level at a listing distance of around 3 metres. You could achieve this with the treaded spikes you have incorporated in the base plinth.

Nice job Petr.