Brilliant!
Thank you for all the information. Lots of good data in the White Paper and with additional data from this excellent forum it should not be too difficult build cabinets.
My idea was to make a L300 tribute with slanting flush front and angled edges like the 4333's/4367, using a back firing port. After reading about the 4367 and also other "lower" floor standing speakers it appears that most argue that they sound better with a stand. That kind of defies the L300 low & wide look. Would the slanting front help enough to compensate for the driver being lower that the listening position? Any other drawbacks regarding reflections aso with having a upward tilting baffle?
The K2 S9900 is the same width as the 4367, do you think that would be a better choice to use that as a template? It is 260mm higher. L300 uses slanting baffle to limit standing waves (i guess) and the S9900 use a rounded back. The rounded back is probably very difficult to produce DIY so maybe some angled sides can get me close enough. Input welcome
Maybe there are some left over empty non finished S9900/S9800 DIY cabinets from the the Danish JBL Hornlet factory bankruptcy a few years ago still for sale?? somewhere??
I will probably go for flared port(s) just for aesthetics, looks more modern even if the improvements limited for home use. At lease on the outside. A friend has printed the ports to SUB18 and M2's so that is probably the way I go this time also. We can print in two parts and shorten as needed before assembly.
I usually use DATS3 to set the port length by trial and error. I have used SW programs but I never get it right. Maybe it is use of material or stuffing that is difficult to model. Typically set it a few Hz lower than element rez as I use DSP and can control the curve there.
I have both D2's and several 4" Nd drivers/diaphragms (except Mg) so i just have to try. I use 4" Be's in my other system on M2 WG's but at the cost of needing UHF in the form of 045's. Works fine but these will be 2-ways and hence most likely not Be's.
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
And it's great that jmpsmash's mom has 4367s! My mom would have come as close to piloting the space shuttle as she would have owning some top tier JBL monitors.
Do you plan to replicate the height of the L300 or 4367?
L300 is 803mm tall, 4367 is 941mm tall.
4367 height is OK to be used without a stand. while the L300 is 6" shorter, and probably why they have a slanted baffle to compensate.
my mom has a stand for the 4367 (~6 inch tall) and she says it sounds better that way. It depends a lot on the listening room and environment. Sitting position will affect the HF height while room modes will affect the LF source location.
Unfortunately due to COVID I have not been able to visit my folks and listen to the 4367.
as for the K2 S9900, personally I love that look. However, back of the envelope calculation shows that with that semi-circular cabinet it barely has 3.5-4 cu ft of gross volume.
I am in the designing stage of building something that has a curve cabinet. but deeper with a cut-off oval shape instead of semi-circle. It will have M2 lens and 2216ND1 woofer. inspired by the design posted in the KM2 thread.
what's the pros and cons of having the port at the back vs front?
Oh... Did I mention she is in her 70s?
Couple of years ago she came to visit me and we were tweaking my system and she was able to tell differences in the 10kHz+ range (verified with FR measurements)
20 yrs ago she had someone build a pair of custom speakers with a pair of LE15A. She was bummed that some friend was letting go of a pair of 2231A and she didn't take them before another friend snatched it. The LE15A speaker didn't age very well with 20 yrs of high humidity in Hong Kong. Most of the drivers have disintegrated so she got the 4367. I told her to keep the LE15A driver which can still be refoamed but so far no urgency to.
RE "what's the pros and cons of having the port at the back vs front?"
In principle none since VLF radiated is omnidirectional. However, with rear firing vent(s) one must not put the cab's back too close to a rear wall as this will impair vent air flow. So that reduces back wall box placement.
Vent works as well either way as long as you have free air flow. On JBL B460 sub the vents are on a side panel near the back. Then this means cab has to have a distance from side wall.
Box placement flexibility is one reason i always put vent(s) on the front panel. Speaker system placement needs to be experimented with for best sound or most pleasing. When vent is not on the baffle that precludes some box arrangements, such as to back or side walls, which one may regret later. My other reason is psycho i guess (lol), simply prefer front firing vent, i get the impression that output is straight to my ears, like for the drivers.
But i can imagine, justified or not, that rear vent sound may not be exactly in phase with the front sound due to a short delay on the back wave from port having to rebound before reaching the listener maybe? Others may have an opinion on this. Regards,
Richard
P.S. Regarding the last point, i can't recall seeing studio monitors, used in a Prof. studio, having rear firing ports. Could this be an indication?
I thought about soffit mount. However, the ones i've seen in recent times were not soffit mounted or up against another surface, but rather "flown" using some ajustable speaker metal support, and angled downwards shooting at the recording engineer's position. In such situation they could have had rear or side firing vents, but they didn't...
Since the manufacturer can’t control where a monitor will be installed, the safe answer is to place the port(s) on the front.
Widget
Yup, agreed. Plus this way one keeps all box placement options available, i.e. box to back wall, in the corner, etc. Nice to have flexibility.
I see your point and it is not really important to have the ports in the back, just look less busy. I had two ports in the back on the ”compact monitor” a few years ago and that worked very well. They were LE1400H + 2451/475SL on M2`s. They are now with a friend and still sound among the best I have been able to build. BSS DSP and Crown CTS as always :-)
However, it feel like I`m passing on the 4367 cabinte design and moving towards the higher cabinets like the S9800/S9900 to eliminate the need for stands. The curved rear is too complicated so I will probably make angled sides. Maybe make them romboid... I need to give that some though as there others in our home having views on such matters...
A pair of empty S9800/9900 cabintes from Hornslet bankruptcy would fit the bill perfectly. Must start searching.
Anyway, 4367 WG´s and 2216Nd-1 is in transit as the last set -1 woofers went with my M2´s to a friend. I also have a set of dual 15”s, dual 14” and 18”s if needed...... I`m not planning to use a sub with these, they are only for 2-channel enjoyment.
I`m going to try to make these phase linear. I guess everyone wants that but it is not that simple, not even with a DSP. My reference speakers from Genelec are both frequency and phase linear. They are near/mid field so they cannot replace the JBL`s, but they sound real nice with their digital correction SW. Probably like a 708P or so.
I bought them to keep the DSP fiddeling at sane levels. It is easy o lose the direction when you can change EVERYTHING.
All input much appreciated.
//Rob
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
Hi Rob , in the world of Baltic Birch there are suppliers of pre formed curved sheets.
Think about drum shells but bigger. How you go about cutting etc is a different matter but I have seen various radii on sheets as high as 48" / 1200
You are in the Nordic region so should be able to dig into industrial suppliers.
Here's a linky from the US but the product will not be made there simply because they could not call it 'Baltic'
http://www.aitwood.com/StoreFront.As...(90%20degrees)
You will need to dig around in the site to see what exists , I have seen 18mm half round
somewhere on this site. I would be surprised if there was not a Skandi manufacturer out there.
Regards Mac
Hi everyone,
Just wanted to get back on this as I have sold the 4367 Kit to a local JBL enthusiast who will continue the build and most likely this thread. His name is Bjorn.
I got some LSR6332 , but that is for another thread.
Thank you for the support.
//Rob
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
Okey, this thread is officially open again. :-)
The first 4367 set was bought by my dear friend Björn but I have a second set inbound that was originally going to a friend that in the end left the table :-( .
So I will build me a set of 4367 clone as originally planned. These will however be faithful to the original design and Björn and his son has put in loads of efforts to re-engineer the design and make the necessary files. Brilliant work form their side. Thank you.
Björn will run original D2 driver and original XO. I will stick to my guns and use my favorite combo 2451 with larger felt back cap and 475Nd diaphragms. I have one new NOS set left.
This means that I will have to move to DSP so any input on curves and filers is much appreciated.
I will keep this thread updated.
Have a nice weekend when it arrives fellow JBL nuts.
//Rob
The solution to the problem changes the problem.
-And always remember that all of your equipment was made by the lowest bidder
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