Monacor SP-310CX Coaxial Driver MLTL's

Dedicated to those large boxes at one end of the room
User avatar
Toppsy
Shed dweller
Posts: 2188
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country
Contact:

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Toppsy » Thu Dec 05, 2019 10:46 pm

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.

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » 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?

chris661
Shed dweller
Posts: 2289
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by chris661 » Fri Dec 06, 2019 4:22 pm

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

User avatar
Scottmoose
Needs to get out more
Posts: 1522
Joined: Sat Sep 08, 2007 11:03 am
Contact:

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Scottmoose » Fri Dec 06, 2019 6:01 pm

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.
'"That'll do," comes the cry of the perfectionist down the ages.' (James May The Reassembler)
Website www.wodendesign.com
Community sites www.frugal-horn.com & www.frugal-phile.com

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » 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

User avatar
The Stratmangler
Shed dweller
Posts: 2053
Joined: Fri Aug 24, 2007 1:50 pm
Location: Rossendale, Lancashire

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by The Stratmangler » Sat Dec 07, 2019 9:41 am

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.
Chris :happy3:

User avatar
Toppsy
Shed dweller
Posts: 2188
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country
Contact:

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Toppsy » 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.

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » Sat Dec 07, 2019 3:49 pm

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

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » Fri Jan 24, 2020 3:46 pm

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
Attachments
54519159-035E-4470-BEA5-1F92B8E44AEE.jpeg
B3C32E0F-D069-421B-A77E-93054003FD04.jpeg
6312BB49-D58E-4A33-A9AA-B462578AA782.jpeg

User avatar
Toppsy
Shed dweller
Posts: 2188
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country
Contact:

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Toppsy » Fri Jan 24, 2020 5:56 pm

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.

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » Mon Feb 10, 2020 7:32 pm

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
Attachments
08B66C58-0F57-4601-9E7E-B0236C411169.jpeg
CBF3B203-AA3E-46EC-8F0D-D564BE798847.jpeg
68FD7FD0-C8F6-4E2D-8640-E3809C8DF557.jpeg

petr.kosin
User
Posts: 7
Joined: Thu Dec 05, 2019 6:54 pm

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by petr.kosin » Mon Feb 10, 2020 8:25 pm

...and some more pictures...
Attachments
B40DD7B1-D462-4400-82C8-B763ADCBA03E.jpeg
B40DD7B1-D462-4400-82C8-B763ADCBA03E.jpeg (20.63 KiB) Viewed 370 times
71600D0D-FEB4-4762-B736-928AE8B45B4A.jpeg
71600D0D-FEB4-4762-B736-928AE8B45B4A.jpeg (39.24 KiB) Viewed 370 times
8D43DDE7-E310-457C-8AC7-23C85CE09A08.jpeg
8D43DDE7-E310-457C-8AC7-23C85CE09A08.jpeg (29.83 KiB) Viewed 370 times

steve s
Needs to get out more
Posts: 1874
Joined: Wed May 30, 2007 6:19 pm
Location: east yorks

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by steve s » Mon Feb 10, 2020 8:32 pm

Those are very nice..
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number

User avatar
Toppsy
Shed dweller
Posts: 2188
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country
Contact:

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Toppsy » Tue Feb 11, 2020 3:17 pm

Top job there Petr they look really nice indeed. Your workmanship is first rate. :notworthy: :thumbup:
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.

User avatar
Ray P
Social outcast
Posts: 3387
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

Re: Monacor SP-310CX Coaxial Driver MLTL's

Post by Ray P » Tue Feb 11, 2020 7:06 pm

Nice job Petr.

Post Reply