Very nice little speakers!
Would be fun to compare them against 4429 some time.
Do you know how the directivity will match in the crossover region? I read somewhere, that the same size of woofer and horn usually is good best-practise (from a directivity point of view). So maybe a 15" is a general better match to the M2 horn than a 12".
Hi,
Maybe the pictures give that impression POS, but these are tiny compared to the DD55000. These would look like your average table top computer speakers if you would place them side by side :-) .
bubbleboy76, I was not aware that the physical width of the WG would influence directivity that much. The M2 WG is 100 by 100 degrees I think, so I hope that should be ok. Several of the JBL K2 series speakers do have much wider horns than their woofers so that gives at least some hope. I will just have to measure and listen when I get that far.
Anyway, LE1400H is a 14" woofer and a sibling to LE14H-3/4 but with a 1401Nd coated cone so the physical width difference compared to a 15" is not all that big.
I certainly hope that these will at least match 4429 given, the larger woofer (albeit that 1200FE is really good woofer), the small format driver in the 4429 compared to the large format SL driver here and that the M2 WG is a newer design. These will also be active with a BSS DSP like the original M2's so maybe that can help a little.
It may also be easier to succeed with a DIY 2-way design compared to a 3-way as the 4429. -Unless you are JBL with "unlimited" design and measuring capabilities. :-)
-More info to follow.
Kind regards and thank you for input.
//RoB
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
The point of view make them look quite impressive, with the horn staring at you from above, like the DD55000 do.
Why not put the tweeter on the side like the DD55000?
Like this? :-)
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
Hi,
As mentioned above the M2 waveguides does not have entirely parallel sides, the guide is 4 millimetres wider in the top. Attached is a picture of how much I needed to mill down to fit into my cabinets.
In the original M2 cabinet the guide is flanked by the sides of the cabinets and they have rounded/angled edges. In my cabinet the guide forms part of the sides. Hence I decided to round of the edges with the router. I will have to respray them anyway . In the attached Picture it is not bolted to the cabinet, hence the gap.
Now it’s time for painting the guides and make grills in front of the woofers.
One step at a time
Kind regards
//RoB
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
No no, one the side like thisOriginally Posted by sebackman
(just kidding, your implementation looks neat and sound!)
Looks like some great progress on both the two way and the three way. Keep up the good work.
Speakers are starting to look great!! They will be pretty cool when painted
I've always been curious about those LE1400, are they any good? Didn't know until you wrote it was a 1401ND/LE14-3 mix
Let me know if you make adapters
While I’m “post bombing” LHF tonight I might as well update progress on the Compact Monitor. I guess that I have to get used to that all my projects keeps going for years instead of months due to lack of time….
The waveguides are all set with parallel sides and all. I tried to paint them myself but with less than desired result. Now they are off to a “real” paint shop for some proper treatment and with additional charges to remove the remains of my futile attempts.
They will be kept black, it’s such a happy color. The WG for the upcoming 3-ways will be Anthracite Gray as per the older JBL horns.
Baldrick, I have no clue as to the performance of the LE1400’s. I plan to mount them next weekend and measure/adjust the porting to get somewhere in the region of 30-35Hz. They will probably be used in Oslo so maybe you can swing by if you find the time. I can post a measuring curve when I get around to do it.
Cabinets are pretty much done and grills ready to mount. As you can see the curvature of the grill follows that of the WG when attached. I don’t think the “mesh” will affect the sound from the woofer and the WG will be open.
I also got some new D8R475Nd diaphragms and mounted in my almost new 2450SL cores. The pair measured very close so I hope it will be good.
Having followed the “charge coupling threads” and being a firm believer I did some math and the size of the capacitors needed to make up a protection but without interfering with the XO was very large. Hence I decided to go without protection cap but with an -8db attenuator. I got some 50w alu housed resistors with low tolerance, in fact low everything , and place my trust into the protection circuits of my beloved Crown CTS amps….
I first made an attenuator for the expected 8ohm diaphragms but when they arrived they were indeed 16ohm so I had to redo them again…
These won't have the 045Ti's , it was just for the Picture. They will go into the next Project.
Getting there.
Kind regards
//RoB
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
The Compact Monitor turned out to be too big for bookshelf and too short for floor standing so I made some stands that should bring them pretty much in M2 original height.
I will use them in an apartment so the stands would have to prevent bass vibrations to be shared with everyone else in the building.
I got some Oak and decided to make a stand that matched the speaker cabinet footprint at the top but was a little wider at the bottom.
It has integrated anti vibration inserts on top and in the bottom of each the pillars and also very soft feet at the bottom. The picture shows the feet and mounts.
I found these feet when looking for feet’s to my SUB1500 HT subs and stumbled on a company in France that does anti vibration mounts for helicopter dashboards. They have a very controlled function and are behave almost fluid but without losing their form.
I use them under my subs that are quite heavy 75kg each and they are completely still even at rather high excursions. But if you push the cabinet at the top it moves to the side. I hope it will work here also.
-A bit crude but I hope you like them.
Kind regards
//RoB
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
Great work like this always takes a little more time. Looking good.
Hey Rob, Those are looking really cool! Looking forward to your impressions.
Always fun learning more.......
Hi Robert,
Nice work on the tap. I did not have the tool to reduce the diameter so I had to find a thin one, which proved difficult.
I currently have one horn tapped with M5 threads, but I will redo them with M6 now...
And the second one is still untouched.
Did you enlarge the hole from the original ~4.7mm to 5mm before tapping the M6 thread?
Intresting those damping "feet"
I have a couple of subs around 80kg each that needs something like those.
Where did you find them?
Hi Johan
Not the exact same model, but you could use these: DVA.6-30-36
Conic feet tend to be better than straight ones (settling vs weight is not linear).
See attached pdf for calculations.
At 20kg per foot (4 feet for your 80kg sub) you would get a 8mm settling, which translates to a 6Hz resonance frequency.
The calculated reduction in vibration transmission would be as follow:
I have been using these, as well as the smaller 20-24 version, but I will now try foam.Code:-6dB at 10Hz -20dB at 20Hz -40dB at 60Hz
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