You're probably pretty close.
You can tune the cabinet once everything is installed.
One method is described here. Page 28
There are also other ways.
2235. Volume Displaced by Driver When Mounted in Enclosure: 6 L
Other drivers?
So why to make two big vents?
If they are too small you will get noise from the air that passes in the tube.
Stuffing
Use glass wool as original.
Glass wool increases the volume in the cabinet a bit.
These 2405H's are rough, but there is nothing that can't be fixed
Someone from LH forums has posted a topic about refurbishment of two 2405 tweeters some time ago, take a look:
http://www.audioheritage.org/vbullet...5-refurb/page2
I second the opinion to use glass woo, I've spoken to some JBL freaks in the past and all of them told me to use only glass wool.
However I'm asking myself if there is any way to put a dust/particle filter on the bass reflex pipes since glass wool is nasty stuff.
I see this concern voiced quite often. I have vintage and new JBL and a ton of pro boxes and have yet to ever notice that any of them have ejected fiberglass. Some of its pro gear that gets banged around and moved a lot. I don't know but it's something I stopped worrying about a long time ago.Originally Posted by martin2395
Barry.
If we knew what the hell we were doing, we wouldn't call it research would we.
There is a Swedish thread, Allram moffar i lådan, where different damping materials are tested. Google translate will probably make it readable. Gullfiber = glass wool. Moff = slang for damping material.
Conclusions are: Glass wool is good for midrange, but not for bass. Wool and twaron are good for all frequencies.
THAT sense for detail makes me speechless!
This baffle blue research is simply amazing.
Thank guys.
Martin, I agree with the fact that glass wool is nasty stuff. I don’t want to use it in the house (sorry Barry).
Filled my L80T’s with sheep wool, which is nice to work with and with good results in the low tones.
More10, I (and my friend Google translator) checked the Swedish thread where they test the damping materials.
I like the way they do the test and included the IKEA bed.
What I miss is the starting point: What are you looking for and THEN try to find it. I still cannot find the 'goal', the 'aim' of the internal stuffing.
Is it to kill as much as possible sound inside the cabinet? And then only for the low frequencies; it's only the 2235 who makes sound inside the cabinet.
The Swedish test comes with wool and twaron to be GOOD...... for ??? damping.
Is glass wool maybe used because of the price?
I'd like to use this special (left over from a project) acoustic damping material which costs a fortune (with a reason). Not for me in this case......
In the meantime searching the web for "damping inside speakers".
Thanks Guido: if you do it, you better do your best.
Nice. Your going to have some first rate speakers when done. Its a happy feeling listening to speakers you built yourself. Its like a drug.
looks better than new!
No worries here! I just think people worry about a lot of things needlessly so I just wanted to share my experience with glass. But, I have a tritium powered exit sign in my bedroom and 10 pounds of mercury on my bench so,,,
The stuff I use comes from a company called CWSI and is lightly coated with something that resembles hair spray. If its not identical to what JBL uses its by far the closest thing I have found. The down side is that it only comes in a great big roll that has to come freight.
If we knew what the hell we were doing, we wouldn't call it research would we.
Hi JBLP,
sorry for too late answer: 0.6m means 60cm.
http://www.audioheritage.org/vbullet...l=1#post352504
so for your box INTERNAL dimensions frequencies (and their multiple) around 172Hz, 295Hz and 530Hz can introduce internal standing waves.
some interesting about damping material can be seen :
http://www.faktiskt.se/modules.php?n...wtopic&t=40658
As I can see from the figures you have 2405H (ferrite ) and 2404H magnets, so I think you can use 2404 magnets and 2405 Phase plug, but using D16R2402 diaphragm ( from 2402 drivers) would reduce 2405 frequency response ...
Regards
Ivica
Hi
Really like your detailed build, awesome quality
I always wanted a 4 way JBL system as well but after reading a couple of books by Philip Newell (1 with Keith Holland) about studio monitor design and studio design I contacted Philip via email and he recommended to stick with 2 way as it's much easier to deal with the phase shift in the system.
He explains it very well in his books.
I have 2205s in 8 cu foot sealed cabinets with Altec Lansing 808-8As on 811B horns.
I use a DBX electronic crossover with a bi-amp and would recommend that you pursue that as opposed to a passive crossover.
Much cleaner sound with an electronic crossover.
Philip Newell also recommended the sealed 8 cu ft cabinet, I had it vented (both 4th order and equalized 6th order) at first but sealed is much cleaner, it is much easier to follow what the bass player and drummer are doing.
I was also using an SAE parametric equalizer but it deteriorates the sound quality.
Read Newell and you will get rid of all your Digital signal processing and EQ.
Your sound quality will improve.
I have ordered 2231s locally to try and get a bit more bass as I don't really need the efficiency of the 2205s.
I also purchased JBL 2425 drivers with 2370 horns to try to find out if the alnico/ceramic debate really means anything as well as the Ti/Al diaphragm thing.
I also have JBL 2447 drivers with an aftermarket horn to experiment with.
My plans are sand filled walls on the 8 cu ft bass cabinets and separate horn cabinets also filled with sand.
Wharfedale used a sand filled back on the early 60s W60 and it's way better damped (dead) than anything I've been able to construct using bracing, dead sheets, extra layers of wood etc.
If I turn up the volume the walls of the cabinet start to move caused by the sound off the back of the bass driver and it muddies up the sound.
(The advantage of a small cabinet I guess)
I just don't like the sound of modern speakers with a tiny bass driver and a dome tweeter, (no dynamics and they sound loud before they really are loud.
My system doesn't really sound loud until it's really loud, I just want more of what I have already.
"Too much is never enough"
My wife thinks I'm nuts but see if I care.
Maybe I'll post some pics as well.
BTW I'm from The Netherlands as well, Obdam in North Holland, moved to Canada in '03.
Good luck with your project and let us know what you drive it with and what it sounds like.
Thanks
Bloys Dekker
Hmm, with 2231A/H may be 2205 can be used as mid-bas, and some 811B "look-a-like" (bi-radial) horn but with 1.5" inch throat used with 2447 ( say at least with Radian 1245-J diaphragm),Hi
Really like your detailed build, awesome quality
I always wanted a 4 way JBL system as well but after reading a couple of books by Philip Newell (1 with Keith Holland) about studio monitor design and studio design I contacted Philip via email and he recommended to stick with 2 way as it's much easier to deal with the phase shift in the system.
He explains it very well in his books.
I have 2205s in 8 cu foot sealed cabinets with Altec Lansing 808-8As on 811B horns.
I have ordered 2231s locally to try and get a bit more bass as I don't really need the efficiency of the 2205s.
I also purchased JBL 2425 drivers with 2370 horns to try to find out if the alnico/ceramic debate really means anything as well as the Ti/Al diaphragm thing.
I also have JBL 2447 drivers with an aftermarket horn to experiment with.
My plans are sand filled walls on the 8 cu ft bass cabinets and separate horn cabinets also filled with sand.
Bloys Dekker
and for sure a kid of UHF driver ( 2405, or may be 2402)...
regrds
ivica
Hey NickH: building them is also like a drug, what to do when they are finished.......
Pos: I was in Poland to visit a furniture-painting-factory and took them (2405 alu splits) with me. They did a nice job!
1audiohack: I'm stuffing them with the modern-lab-tested-sound-absorption-material and just see what it brings.
Ivica: So I will have to test them and see if there are standing waves. Take then the proper action?
Hoi Kawasakitech: what's number one on your list: Kawasaki or JBL? Your wive prefers JBL?
So you're really busy with a serious project: filling cabinet walls with sand.
I remember some audio freaks at the university testing concrete cabinets in the concrete lab. Talking about damping dead!
I will pursue your proposed crossover setup like this:
Driving it with:
I'm infected with the Sansui Vintage virus. I will drive it with a CA/BA-2000 set and the bi-amp will be the AU-11000A.
I also still have my first S(on.)ansui AU-7900. A good and warm sound.
So what system do you have now? Show us some of your projects.
Thanks Bloys; defend our cheese and tulips over there, cheese-head!
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