View Full Version : 2245 up to 300hz?
Hello all,
This is my first post on this forum, though I've been reading it for some time now.
I have a question regarding the low end of the 4345.
I read that it was not a good idea to get a 18" up to 300hz, and that the 2245 was tuned to high in the 4345.
Does that means that a 4345 is less accurate in the 100-300 zone than a 4344? Even bi-amplified?
Would a 4344+sub (2245 or maybe W15GTI) sound better than a 4345?
I'm asking this question because I have the project of building a studio monitor style speaker, with something like 2245+2123+2426/2342, with an horizontal arrangement similar to a 4412.
This could be called a 4444 or 4445 I guess...
I know that the 2123 will not go as low as a 2122 (it is crossed at 340hz in the 4344mk2), so maybe it would be better to use a 2235 instead of a 2245 and cross it around 500hz? Or a 2226+2245 ?...
The only drivers I already bought for this project are the two 2123, so all other options are still open and your input would be more than welcome!:bouncy:
speakerdave
05-27-2007, 07:22 AM
Good question, pos, welcome to the forum. I think the problem you are puzzling over should be recognized as signifying that in designing and building a speaker compromises are necessary. It becomes a question of which ones you insist on designing out of your speaker and which ones you will settle for.
If you want to build a speaker like the 4345 the EASIEST thing to do would be to copy the 4345 EXACTLY, even though it would mean back-tracking and replacing your 2123's with 2122's.
You did not say who wrote what you read about not using an 18" woofer up to 300 cycles. Maybe you should just ignore him. Really, the only way you can answer the doubt it has raised is to hear for yourself a pair of 4345's (that have been biamped).
I think you should study Drew Daniels's system which is described here on the Lansing website. It is one solution to the problem you describe. Also, use our search engine in the forums and try to find a description of Robert H's system. Both of these systems use a 15" in the frequency region you are talking about, with a subwoofer below and a ten-inch above.
One option you did not mention is to consider the bass layout of the 4435 and Everest II. The 2234's used on the 4435 are still available new from JBL Pro.
David
Drew's Clues: http://www.audioheritage.org/html/perspectives/drews-clues/drews-clues.htm
Thanks!
Here are the quotes about the 18" at 300hz:
http://www.audioheritage.org/vbulletin/showpost.php?p=150803&postcount=19
http://www.audioheritage.org/vbulletin/showpost.php?p=150804&postcount=20
And I remember Giskard said something like he didn't liked the tune frequency of the 4345 (too high) but I cannot find where. (maybe I misunderstood, which is quite possible).
I also read Greg Timber's post in the 4345 club thread. He said that the 2245 was a great driver when used as a sub for VLF, but quite difficult to drive (biamp mendatory) and not so articulated (compared to a LE14) when used as a LF tranducer.
In fact the 4345 is the only model that uses it that way.
I never had the chance to listen to a 434X, so I really wonder how a 4345 and a 4344 compare in the low end (not VLF). Everything I have read tend to prove that the 4345 performs better in practice.
You are probably rigth about the dual 15" approach. It was used in most modern JBL monitors (4435, DMS-1, new everest...), so it should be the best design.
But 2245s are easier to find than 2235, because they where also used in PA.
Maybe I could find a 2225 and have it reconed though, but then I would have to find 4 of them!
And, well, I would really love to have something like a giant 4412 !
Just imagine the beast that would be!
remusr
05-27-2007, 10:46 AM
Would there be material difference in transients with an 18" or a 15" up to the 300Hz range? The 2245 has a larger & heavier cone than the 2235 with a larger magnet assembly than the 2235 to control it. Different specifics in suspension and magnet structure so lots of variables but they share a similar design philosophy in SFG w/ Flux Stab Ring etc and designed response range down to 20Hz.
The JBL brochures' freq response curves show the 2245 staying flat to 40Hz and -15dB at 20Hz (10ft3 box tuned to 30Hz) with a 2235 flat to 50Hz and -15dB at 20Hz (5 ft3 box tuned to 30Hz) so the 2245 may have some advantage in low bass.
For reference, and you may want to consider buying one of their kits, Gold Sound www.goldsound.net (http://www.goldsound.net) runs the 15" higher in their kits (2235 in 6 ft3 Kit#11 w/ 300Hz XO to 8" 2118H, 2245 in 12 ft3 Kit #14 w/ 80Hz XO to 12" 2206H).
I would say that the 2245 sounds great in my 4345 running passive (not biamp) crossing over at ~300Hz. It is far superior to the 2235 as used in my 4430's in the low bass and its overall articulation of bass instruments is also better. The sound is obviously influenced by room effects, enclosure, crossover & interaction with the speaker it crosses over to. Both have been placed in the same room location as well as many others. In the 443x series the 2235 is asked to go to 1000Hz where it is not the optimum driver - don't know if that affects its low bass performance significantly. So far as dual LF drivers in JBL systems I have only heard my 4435's. I really do like their low end as well, using 2234's, but find it not as quick or articulate as the 4345. The 4435 also does not image very well in my room, a small part of which may be due to dual speakers in the low bass. Neither system is currently biamped, but are using a good Mac MC352 power amp, and maybe that situation would change everything.
Roy
Zilch
05-27-2007, 11:57 AM
The 4435 also does not image very well in my room, a small part of which may be due to dual speakers in the low bass.Extremely small, I'd say, considering the frequencies at which the second woofer operates.
That's not "imaging" territory, in my experience....
Robh3606
05-27-2007, 01:53 PM
Hello pos
Welcome to the site.
Does that means that a 4345 is less accurate in the 100-300 zone than a 4344? Even bi-amplified? Would a 4344+sub (2245 or maybe W15GTI) sound better than a 4345?
I have 4344 wanabees. They are biamped with a JBL DX-1 active crossover. With room gain they simply don't need a sub at least not in my room. Run active the 2235 sounds just fine. I can't say anything about a 2245/2235 comparison as I have never done one.
I'm asking this question because I have the project of building a studio monitor style speaker, with something like 2245+2123+2426/2342, with an horizontal arrangement similar to a 4412.
That is similar to my active set-up which I ran for a couple of years without changes. I used an E-145 as my 300Hz and lower driver with subs under them. I also used the 2344 horn as opposed to the 2342. It was a fun system and the 2123 is a very nice midrange driver. I still run the subs, E145 and 2123 but the top end has changed to a 2435 on a PTH1010 waveguide. You have to post some pictures for us. Are you going to run this active???
Rob:)
Ian Mackenzie
05-27-2007, 02:24 PM
Pos,
Why not build a quasi 4344 with twin 2235/2234 woofers. You are going to have trouble finding the 2122H mid cone. The 2123 is more common.
The more recent JBL woofers used in the consumer series 2 way systems with a newer compression driver may be more hifi and better if you want a easier amplifier load.
I dont want to get into discussing the in's and outs of the 4345 tuning on the public forums but are happy to send a pm. Un fortunately there is a lot of mis information about these details as you have read in the links about.
However, one of the problems with the larger 18 inch woofer is it need a larger box to really work properly. The large cone also does a nice job a coupling to the room boundaries hence we ready about technically deficient applications in the 100-300 region..
The 18 inch woofer however does move more air and is has more linearity.
If you want to use the 18 inch woofer you must get it off the floor or use an equaliser to smooth the response. With such a large box this is not alway practical!
JBL typically used an 8 cu ft - 10 cu ft box for the 2245.
In one diy project I personally used the 2245 in a 10 cu ft box (net volume) properly tuned to 27.2 hz. In that system I used an Audax 8 inch mid cone HT210. I suggest you biamp
Later I decided to use the 2344 horn and it works very well. Using the 2344 bi radial is a more open sounding but you must have a room with not many flat bare walls otheruse it will not image correctly.
Depending on the room you can vary the tuning +-2 hz and get a satisfactory result.
You will need to trial a few options. I suggets you make up some test boxes (un finished timber) and see what works best in your situation.
soundboy
05-27-2007, 02:30 PM
...I have the project of building a studio monitor style speaker, with something like 2245+2123+2426/2342, with an horizontal arrangement similar to a 4412.
The only drivers I already bought for this project are the two 2123, so all other options are still open and your input would be more than welcome!:bouncy:
Not to be redundant, but what are the design goals? Maximum efficency and output, or maximum transparency, articulation, and detail?
For maximum output, I would go with a 2241/2242 to 300hz. For maximum articulation, and would go with a 12" or LE14 to 300 hz, and use a 2245 below 80hz. How low does it have to go? How many cabs do you want?
Like it has been said, it is all a trade off...the 2241's would play a lot louder, and still get 35 hz or so, in a single cab arrangement, and, they would be punchier in the midbass than a 2245H....
I tried the 2245H's for live SR years ago, and they just don't get it above 100hz, like a 2240, or 2241 did, in my experience...not enough efficiency and punch...they were in 10 cu ft, tuned to 30 hertz, I think. Again, this was for live sound..
JBL used the 2241 and 2123 crossed at 600hz for a PA cab years ago (4738?)....they sounded killer for stage monitors....but I never put a pair in my living room, and listened....maybe that's a good thing???:D
My 2245H subs in two different systems sound killer below 80hz in my home...nothing better, IMHO. One is below 4408's, the other below a Dynaudio 3 way with 10" midbass....they both blend superbly....not slow or boomy at all...in fact, they both sounded even better after I re screwed the sheetrock to the studs behind each one....the nails had loosened and were out an 1/8" from the walls:bouncy:
speakerdave
05-27-2007, 03:39 PM
Here are the quotes about the 18" at 300hz:
http://www.audioheritage.org/vbulletin/showpost.php?p=150803&postcount=19
http://www.audioheritage.org/vbulletin/showpost.php?p=150804&postcount=20
Oh, those guys! :o:
And I remember Giskard said something like he didn't liked the tune frequency of the 4345 (too high) but I cannot find where.
I'm guessing that Giskard was talking about the box size being too small and the port tuning too high to make the most of the 2245's bass capabilities. Greg Timbers said the same thing.
But that is a perfect example of the kind of compromise I was talking about. The 2245 in a smaller-than-optimum 9.5 cu. ft. cabinet would take away some of the bass but would help the woofer in the upper part of its range. If you put the woofer in a larger enclosure, yes, you would want to cross out of it lower in the upper bass, as soundboy has said. But much lower and you will not be able to use any of the purpose-built 10" midranges in the way they are used in the large four-way monitors, because you would need to make a larger dog box, maybe even a ported one, and that would compromise performance in the upper part of IT's range due to increase in size of the dog box and greater excursions in the lower part of its range. So, you would need to identify a driver to use in the upper bass, lower midrange. The 12" 2202 would present the same problems as the 10's. If you choose a 15", then you must lower your crossover to the treble horn, which would require a different horn, maybe a 2" compression driver. And on and on.
You are probably rigth about the dual 15" approach. It was used in most modern JBL monitors (4435, DMS-1, new everest...), so it should be the best design.
But 2245s are easier to find than 2235, because they where also used in PA.
Maybe I could find a 2225 and have it reconed though, but then I would have to find 4 of them!
Yes--it's going to pay to observe JBL's latest thinking. By the way, if you choose to follow the example of the 4435, it's 2234's you want, not 2235's. If you have frames reconed for the purpose, it's a simple matter of leaving out the mass ring of the the 2235 kit.
Or, you could get some 1500Al's. I believe they are slightly easier to get in Europe than here.
David
Zilch
05-27-2007, 04:26 PM
I stay out of 43xx discussions, 'cause I don't do them.
But I'm not above pushing the envelope ahead 30 years or so:
http://audioheritage.org/vbulletin/showpost.php?p=170474&postcount=24
[Send Mr. Widget over here.... ;) ]
Ian Mackenzie
05-28-2007, 01:24 AM
Pos,
It might be worth looking for an LE14H.
It does not need a big box and does many things very well according to the JBL folks;).
Ian
Would there be material difference in transients with an 18" or a 15" up to the 300Hz range? The 2245 has a larger & heavier cone than the 2235 with a larger magnet assembly than the 2235 to control it. Different specifics in suspension and magnet structure so lots of variables but they share a similar design philosophy in SFG w/ Flux Stab Ring etc and designed response range down to 20Hz.
The JBL brochures' freq response curves show the 2245 staying flat to 40Hz and -15dB at 20Hz (10ft3 box tuned to 30Hz) with a 2235 flat to 50Hz and -15dB at 20Hz (5 ft3 box tuned to 30Hz) so the 2245 may have some advantage in low bass.
Ok, so maybe the 2245H used that way is not optimum in the sense it will not go as low as it could in a properly tuned enclosure, but will not be more colored in le LF than a 2235.
That is similar to my active set-up which I ran for a couple of years without changes. I used an E-145 as my 300Hz and lower driver with subs under them. I also used the 2344 horn as opposed to the 2342. It was a fun system and the 2123 is a very nice midrange driver. I still run the subs, E145 and 2123 but the top end has changed to a 2435 on a PTH1010 waveguide. You have to post some pictures for us. Are you going to run this active???
That is a very impressive system you have here!
I will have some questions about the top end also, maybe in another thread.
Yes I want to run everything active, using a DCX2496 that I plan to buy. The DCX has 6 outputs, which is parlty why I want to stick to a 3-way design.
It is surely not the best device, but if the DMS-1 did sound good with their old digital crossover then it cannot be that bad.
The digital crossover will allow me to put delays on each transducter, and also to play with crossover frequencies. It also has some nice parametrical eq, which could be sufficient to flatten the horn response.
I do not have any picture to post yet. The only things I build so far are two little 14L sealed boxes for the 2123. I put them on top of my 4425 and did some testing, removing the 300-1200 zone from the 4425 and feeding it to a separate amplifier for the 2123 using my PC soundcard.
It does not sound really good, mainly because of the passive crossover in the 4425 that is already operating in the 1200 range. Maybe I should try 1500 or even higher to minimize this.
The ideal would be to test on a 4430, but I don't have any.
However, one of the problems with the larger 18 inch woofer is it need a larger box to really work properly. The large cone also does a nice job a coupling to the room boundaries hence we ready about technically deficient applications in the 100-300 region..
The 18 inch woofer however does move more air and is has more linearity.
If you want to use the 18 inch woofer you must get it off the floor or use an equaliser to smooth the response. With such a large box this is not alway practical!
JBL typically used an 8 cu ft - 10 cu ft box for the 2245.
In one diy project I personally used the 2245 in a 10 cu ft box (net volume) properly tuned to 27.2 hz. In that system I used an Audax 8 inch mid cone HT210. I suggest you biamp
Later I decided to use the 2344 horn and it works very well. Using the 2344 bi radial is a more open sounding but you must have a room with not many flat bare walls otheruse it will not image correctly.
Depending on the room you can vary the tuning +-2 hz and get a satisfactory result.
You will need to trial a few options. I suggets you make up some test boxes (un finished timber) and see what works best in your situation.
The DCX with allow me to do a lot of trial and error testing I suppose.
The speaker will *have* to be off the floor because it will have a horizontal layout, à la 4412. I will also have to find/make some nice stands...
It might be worth looking for an LE14H.
It does not need a big box and does many things very well according to the JBL folks
The idea of a not-so-big box is appealing!
I'm guessing that Giskard was talking about the box size being too small and the port tuning too high to make the most of the 2245's bass capabilities. Greg Timbers said the same thing.
Yes, I understand now. So that does not mean a 2245 will not perform as good as a 2235 is this situation. It will just not perform as good as it could have. That is fine for me.
Or, you could get some 1500Al's. I believe they are slightly easier to get in Europe than here.
Not sure I will be able to find this in France. Maybe in Germany?
But I guess this will be quite expensive.
Not to be redundant, but what are the design goals? Maximum efficency and output, or maximum transparency, articulation, and detail?
I want a studio monitor.
Greg Timbers said the 434X were "effortless, dynamic, pretty low in coloration and really "alive"".
He also said this :
.' They are a little vague by today's standards in terms of precise imaging and although they are very low in intermodulation effects, they are not as detailed as really good lesser way designs.What I am looking for is something with a real JBL sound: generous, alive, effortless. But I would also like to have a detailed sound, to be usable as a studio monitor.
Like it has been said, it is all a trade off...the 2241's would play a lot louder, and still get 35 hz or so, in a single cab arrangement, and, they would be punchier in the midbass than a 2245H....
I tried the 2245H's for live SR years ago, and they just don't get it above 100hz, like a 2240, or 2241 did, in my experience...not enough efficiency and punch...they were in 10 cu ft, tuned to 30 hertz
So you think a 2242 would be better for low mid than a 2245? And a 2241 would be even better?
Looking at the specs the mamixum recommended frequency for the 2241 is 800hz, whereas it is 1000hz for the 2245 and 2242.
Is it an indication of anything?
As I understand it, if I want more articulation and more precision in the low end I should go the LE14 way, but if I want something effortless and "alive" I should go the 2241/2242/2245 way. A dual 2235 or 2234 would sit somewhere in between (but then it would require more than the 6 outputs of a DCX2496).
I think I could sacrifice a little bit of precision to get the real JBL feeling!
If I could have something as precise as a 4430, but with more bass and more mid, then I would be really happy!
remusr
05-28-2007, 11:38 AM
A pair of vintage 4842 (or clone) with dual 2245h's would be very interesting. 1200W, 126dB, 25-250Hz. Hide them behind the couch.
Ian Mackenzie
05-28-2007, 02:22 PM
I want a studio monitor.
What I am looking for is something with a real JBL sound: generous, alive, effortless. But I would also like to have a detailed sound, to be usable as a studio monitor.
As I understand it, if I want more articulation and more precision in the low end I should go the LE14 way, but if I want something effortless and "alive" I should go the 2241/2242/2245 way. A dual 2235 or 2234 would sit somewhere in between (but then it would require more than the 6 outputs of a DCX2496).
I think I could sacrifice a little bit of precision to get the real JBL feeling!
If I could have something as precise as a 4430, but with more bass and more mid, then I would be really happy!
Firstly,
Tell use what sort of room you are going to use them in? How big, construction, floor coverings?
If you have some software model the woofers and you will begin to understand what they do.
If you have the real estate look at the Drew Daniels system. A scaled down version might be a 2245, a 2220 mid bass, the 2123, 2397 smith horn and 2405. Also look at the Westlake designs as it will give you some ideas. Spend some time browsing the forums threads, there are some interesting projects.
Dont attempt to design your own system unless you are prepared to do a LOT and trial and error. A DEQX is not your Angel to creating a properly designed system. Its a tool. You appear to want a customised solution.......but are asking us for the answers. It comes down to taste and your own expectations. A diy loudspeaker is more about the journey then the end result.
Keep is simple. Build the 4435 (use 2234H woofers only) design to start with. Use it for a while then try some other horns like some other members are doing with the more recent JBL drivers and look at a super tweeter.
With the 4435 the horn goes down the 1000hz. Its a nice set of compromises. If you can find a good horn and a driver to go lower, ie 650hz or thereabouts that might be the next (expensive) step. The buy some 1500AL woofers (next expensive step).
A pair of vintage 4842 (or clone) with dual 2245h's would be very interesting. 1200W, 126dB, 25-250Hz. Hide them behind the couch.
A double B460 !!
I guess the present version of this design is the 4642A (double 2241H)
Zilch
05-28-2007, 03:29 PM
The proposed design is an upscaled 4412, horizontal, using 2245 woofer, 2123 mid, and 2426/2342 high, clustered, presumably, with "monitor" performance, having more bass and better mids than 4430.
Plus dual 18" sub behind the couch.... ;)
Ian,
I already browsed a lot of threads of this forum and saw a lot of very interessting designs.
I am certanly not an expert in anything and this is going to be a long journey.
I am not a carpenter, and building cabs will be very difficult, but I don't mind if they look ugly (at least for the first iterations).
I do not know a lot in electronic, and bairly know how to solder a capacitor, but I will rely on a digital crossover so I should just have to plug cables.
I do not fully understand driver parameters (tuning, box volume, etc.) but I can rely on existing design for each frequency range and driver (that is the most misleading part arguably).
So yes, I am definitly ready for a lot a trial and error. Lots of trial, lots of error, lots of fun!
The only driver that I currently have is a 2123, so I will begin with it and see where I can go.
I am sorry I asked so much questions here. This is my first thread on this forum, and as I have been reading it for a long time I had (and still have) a lot of questions pending in my head...
Interesting parts do not show up very often on ebay in France, so I guess I will just grab the first pair of LF drivers I can found for a reasonnable price (223X, 224X, LE14H-X), and see what I can get from them.
The proposed design is an upscaled 4412, horizontal, using 2245 woofer, 2123 mid, and 2426/2342 high, clustered, presumably, with "monitor" performance, having more bass and better mids than 4430.
Plus dual 18" sub behind the couch.... ;)
Hey, the dual 18" would only be used when I am not at home (I could not stand the pressure) to keep the neighbors angry. :D
In fact I prefer no sub at all, if two speakers can do the job. And that will certanly be the case, even with a single 15".
Do you think these goals are not realistic? (upscaled 4412, 4430++)
I currently have a nice pair of 4412 and I really like their sound (beside their lack of bass). I just want.... more of it!
soundboy
05-28-2007, 05:04 PM
I currently have a nice pair of 4412 and I really like their sound (beside their lack of bass). I just want.... more of it!
A 2245, 2123, and a horn, is not going to remotely resemble the sound of a 4412. Why not just add a 18" sub? I see a lot of guys that try to re invent the wheel. Been there, done that:banghead:. Lot's of headaches and hours....The crossover is absolutely vital, and even with a computerized LEAP design, a 2245 up to the midrange, with a 10" and a Horn isn't going to have the same delicacy, detail, smoothness, transparency as a 4412. It will be a lot louder, more dynamic, and effortless....at high volume levels. The high end on the 1" driver and biradial will get harsh at those levels, as well...At low to medium levels, the 4412 will be more detailed and transparent, with a sub. Unless you use a TAD horn driver, you will never get the high end air and detail of the 035 tweeter in the 4412. From experience, it's not gonna happen... but if loud and punchy is your goal, that should be obtainable with the correct crossover frequencies and slopes.
It could sound great with the right driver blend...but I still think that the 2245's belong in a sub below 80hz, with one of the other drivers suggested for the midbass below the 2123...LE14, 2234, etc.
Just my two cents from years of breathing too many solder fumes :D
boputnam
05-28-2007, 05:10 PM
And I remember Giskard said something like he didn't liked the tune frequency of the 4345 (too high) :no: :no: :no:
...but I cannot find where. (maybe I misunderstood, which is quite possible).:yes:
The 2245 is quite efficient, and very able to run to 300Hz. Giskard has remarked time and time again about it's high sensitivity and tonality. They do require large cabinets.
The Link and this image are taken from the Technical Reference area of the forum, in-particular under Transducer Information (http://audioheritage.csdco.com/vbulletin/forumdisplay.php?f=59). This area of the forum is rich with JBL engineering info.
The high end on the 1" driver and biradial will get harsh at those levels, as well...At low to medium levels, the 4412 will be more detailed and transparent, with a sub.
You are probably right.
But I also currently have a pair of 4425, and even if I still prefere the 4412 (for the mid), I find the high end of the 4425 very pleasant and transparent. It does not go really high, but it seems more accurate thant the 035. The 4412 are also too directive in the high.
So if I have to sum it up, I would say what I'm aiming for is:
- the mids of the 4412 (THE most important frequency range to my taste)
- the highs of the 4425 (transparency and directivity)
- some good bass
and the solutions could be:
- 2123
- 2342
- 224X or 223X or LE14 or ...
But it seems I will have a hard time trying to build something better to my hears than my 4412, so myabe I should just go for a nice little sub as you suggest (W12GTI?...).
Nah, now that I have this 2123 I cannot go back! This is already too late :banghead:
:no: :no: :no:
here is the message that misled me:
http://audioheritage.csdco.com/vbulletin/showpost.php?p=6045&postcount=4
speakerdave
05-28-2007, 07:15 PM
. . . . Nah, now that I have this 2123 I cannot go back! This is already too late :banghead:
Well, you certainly have a nice pair of midranges there, and in my opinion you are starting with the right driver to build around. Please keep us posted on developments.
David
We go about things all wrong. In early HiFi publications you read about people building the house around the infinite baffle or the folded or sometimes even straight bass horn. I wonder if stereo brought as much evil as it did good. I'm kidding of course, I think, sort of. If a hurricane was coming you could all go down into the horn. I have always wondered what they listened to on these monophonic monsters. What was there for media? I know that some of what I've read was at least as serious as the more serious stuff here and I'm sure it wasn't $100.00 ft power cord as there is science there I just wonder where the media was.
speakerdave
06-06-2007, 01:55 AM
I've been reading some old threads about the JBL 8", 10" and 12" midrange cones, and I need to qualify some of the things I said earlier in this thread. The 2122 (and the 2108) can indeed work down below 100 Hz in a fairly small sealed enclosure. They have a small half-roll foam surround, but a fairly light cone. Whether it would be advisable to look to these drivers for a lot of upper bass is another question. I certainly would not run a 2122 down to 80 Hz to meet a 2245. That would be a gross mismatch in output capacity.
In the L212 the 8" 2108/112 was used without a high pass filter in a .4 cu ft enclosure, and it was expected to perform down to 70 Hz. But . . . two of them (one in each of the satellites) were matched to a single 12" subwoofer, and the output capacities were balanced.
David
4313B
06-06-2007, 04:43 AM
I certainly would not run a 2122 down to 80 Hz to meet a 2245. That would be a gross mismatch in output capacity.I did it in several custom systems over the years but usually crossed over to the 2235H instead of the 2245H. Output capacity wasn't an issue at all since the systems were bi-amped.
In the L212 the 8" 2108/112 was used without a high pass filter in a .4 cu ft enclosure, and it was expected to perform down to 70 Hz. But . . . two of them (one in each of the satellites) were matched to a single 12" subwoofer, and the output capacities were balanced.I used two B212's with my L212's, again bi-amped rather than using the built-in E212's. I also used two B380's with a pair of L212's for one custom installation and again, no issues.
The only problem with both these transducers is the very short VC. But for moderate volume they work just fine in this kind of application.
I tried to find old JBL models that used the 2123, to see to what woofer and horn they were matched, and found these:
JBL 4716A (http://www.jblproservice.com/pdf/Sound%20Power%204700%20Series/4716A.pdf)
http://fr.sonofanzine.com/img/produits/thumb2/8/4/84269.jpg
This is a little PA box with 2123 and 2416 on 2342 (with ports integrated in the horn). In this configuration the 2123 are used down to 100hz or so, or maybe 300hz when used with a sub.
Does anybody have experience with these?
This is exactly the conbination I want to use for the mid/high section. This is quite disappointing to see that JBL see it as a PA box though...
So, am I going the in the wrong direction, trying to turn a PA design into a "studio monitor"?
Robh3606
06-09-2007, 03:26 PM
So, am I going the in the wrong direction, trying to turn a PA design into a "studio monitor"?
You worry too much. You already know you like the 2416 2342 top end. Just do it. It's not like you can't change things down the road.
Rob:)
Sure!
But I have to wait till I can find a good deal for 2416/2342 on ebay before I really "do it" (I just sold my 4425).
Plus I will have to find a woofer. I will try to by a new LE14H-3 (but 433 euros per woofer from harman france is too expensive for now).
This give me plenty of time to think/expect/regret before even having cut any piece of wood !
Some updates on my project.
Thanks to your input I am now pretty confident on the final aspects of my project.
6 months have passed and I now have all the drivers I need. I still need to get the 2245's reconed though.
The drivers are, 2 x ( 2245H + 2123H + 2435HPL + 2407H )
The horns will be PT-F1010 for the 1.5" and Dayton H45E (http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=270-314) for the 1"
I will use an active crossover (on the PC, using an 8 outputs soundcard).
I wanted to retain the 4412 spirit, but with an option for vertical orientation (more realistic in my current listening room), so now I plan to go the 4343/LSR32 route with a rotary panel.
The codename for this projet will be LSR6345 :D
Here are some scaled pictures of what it should look like!
I am not in a hurry so I will wait to raise sufficient money and components (2245 recone kits, horns, active filters hardware and software, passive protection filters, HF/UHF amps, wood and... skills) before completing the whole project !
please tell me what you think!
Robh3606
12-15-2007, 09:32 AM
Nice!! Good thing you have neos on the rotating panel. It should be fun and it could be a nice sounding system. You are probably going to need some passive compensation on the 2435 unless you go the digital crossover route. The EQ needed for them is parametric. A simple in line cap won't do.
Rob:)
You are probably going to need some passive compensation on the 2435 unless you go the digital crossover route. The EQ needed for them is parametric. A simple in line cap won't do.
Yes I plan to use digital crossovers, using a PC and a quality 8 outputs soundcard.
I currently use a cheap creative lab 5.1 soundcard which gives me 6 outputs that can be used as a digital crossover using foobar2000 together with a plugin (classic and FIR crossovers, with delay). It is limited regarding EQ but other software can be used for that.
rs237
12-16-2007, 05:17 AM
using a PC and a quality 8 outputs soundcard.
Pos Hello,
With the sound card is a good idea. I use the Lynx Two B, six outputs, two inputs, for a three way system. I have my CDs gegrabbt on a NAS server saved (raw not mp3).
The sound quality is very good. Some CD player for a few thousand $ sounding not so good.Also, you will have many opportunities for lossless editing, filtering, frequency response corrections, delay, resampling (CD 16Bit/44, 1kHz to 24bit/192kHz) etc.
regards
juergen
richluvsound
12-16-2007, 06:16 AM
Hi Pos,
If you need help tp get started on the cabinet build. I'd love to come and help get you started for a couple of days. Just say the word" EUROSTAR"
Rich
John W
12-16-2007, 09:37 AM
Look great! I have a setup similar to this that sounds fantastic.
Don't forget to plan for the dog box behind the 2123. I'm not sure of the exact size you'll need. Also, the oval port may be a bit of a challange to build and tune.
Hi Pos,
If you need help tp get started on the cabinet build. I'd love to come and help get you started for a couple of days. Just say the word" EUROSTAR"
Rich
That would be great! I will store this magic word -EUROSTAR- in my mind for when I am ready with all the parts! :)
Right now I am not quite sure with the dimensions of the box. I have to keep it small for the wife to accept it in the living room.
Pos Hello,
With the sound card is a good idea. I use the Lynx Two B, six outputs, two inputs, for a three way system. I have my CDs gegrabbt on a NAS server saved (raw not mp3).
The sound quality is very good. Some CD player for a few thousand $ sounding not so good.Also, you will have many opportunities for lossless editing, filtering, frequency response corrections, delay, resampling (CD 16Bit/44, 1kHz to 24bit/192kHz) etc.
regards
juergen
Yes with that sort of setup you have the best possible transport! Have you tried the FLAC lossless compression file format?
One thing that afraid me a lot is connecting HF/UHF drivers directly to the amp with the sound card as a source: you never knwo if the software of the computer can have a bug a send some fullband signal to their input...
I will use bypassed/biased protection caps at line level before the amp for that, plus some protection systems (http://www.dcx2496.fr/protect.php) inside the speaker, just before the HF/UHF drivers.
Look great! I have a setup similar to this that sounds fantastic.
Don't forget to plan for the dog box behind the 2123. I'm not sure of the exact size you'll need. Also, the oval port may be a bit of a challange to build and tune.
Yes your setup was a great inspiration for me. Mine is very similar to yours, expect the use of 2245's instead of 2241's, and of course my inability to craft these beautiful horns you have for HF/UHF.
I read that you sold your DCX2496, what are you currently using for your crossover?
The oval port will be difficult. I was thinking of distorting some cardboard...
But I think I will start with a closed design for evaluation. A 8 cu ft internal volume would give me sort of a bessel alignment when sealed, with minimal stuffing (only on the panels).
Robh3606
12-16-2007, 10:31 AM
Right now I am not quite sure with the dimensions of the box. I have to keep it small for the wife to accept it in the living room.
If that's the case you may want to change your bass driver. The 2245 needs a big box. By the time you add the bracing and subenclosure for the midrange it's BIG. There is no way around this.
You may want to look at either a 2235 or an LE-14H-3. Much smaller boxes. The LE-14 would be the best for WAF and it is a damn nice driver only problem could be availabillity.
Rob:)
If that's the case you may want to change your bass driver. The 2245 needs a big box. By the time you add the bracing and subenclosure for the midrange it's BIG. There is no way around this.
You may want to look at either a 2235 or an LE-14H-3. Much smaller boxes. The LE-14 would be the best for WAF and it is a damn nice driver only problem could be availabillity.
Rob:)
no Rob, no way! It is too late to change the drivers :D
I want these big 18"! Those small 14" are for kids !! :barf:
8+0.5 cu ft internal is something I should manage to get accepted in the house
richluvsound
12-16-2007, 11:26 AM
Pos,
the 18" needs minimum 9 ft2 .even better would be 9.5-10 . see what GT said about it ! maybe make the baffle thinner and the box deeper:) PM Ian , see what he thinks.
Rich
You are probably right, but it will have to live with a smaller volume for now...
8 cu ft is what the 4645/B460 gives to the 2245, and that is also the size of the "small" box in the 1983 article. With a low tuning and some eq (which I hope I can add with small group delay penalty using the PC) it seems quite good.
I also read this thread:
http://www.audioheritage.org/vbulletin/showthread.php?p=9616
2245 in a sealed enclosures could well be what I need for my room, and a 8 cu ft volume would let me try both ported/sealed design. If it fails then I could build a bigger box, keeping the unchanged HF panel.
This will be the first box I build, maybe I am crazy to begin with such a big box :banghead::baby:
rs237
12-17-2007, 01:01 AM
Yes with that sort of setup you have the best possible transport! Have you tried the FLAC lossless compression file format?
One thing that afraid me a lot is connecting HF/UHF drivers directly to the amp with the sound card as a source: you never knwo if the software of the computer can have a bug a send some fullband signal to their input...
I will use bypassed/biased protection caps at line level before the amp for that, plus some protection systems (http://www.dcx2496.fr/protect.php) inside the speaker, just before the HF/UHF drivers.
hello Pos,
no i have not tried FLAC. Hard Disk memory is so cheap, 200EUR (280 $) for 1TerraByte takes place for 1500 CDs. For the best sounding filter I the CD and save 3 files (high, mid, low). Then I play them simultaneously, or delayed for the mid and high. Very low Prozessorlast its the result.
Protection Cabs are ok. I will for the HF / UHF DIY Tube Amps . Here, I can easily limit the frequency response 1 or 2 octaves below the filter frequency limit.
regards
juergen
JBL 4645
09-24-2008, 04:51 AM
I was thinking 300Hz and I seemed to remember reading it had limit max up 2Khz so I looked around Google image for the profile specs on the JBL 2245.
hjames
09-24-2008, 05:25 AM
I was thinking 300Hz and I seemed to remember reading it had limit max up 2Khz so I looked around Google image for the profile specs on the JBL 2245.
As opposed to going to JBLPRO and just reading the specs there?
http://www.jblpro.com/pages/components/2245h.htm
pointing to the brochure here:
http://www.jblpro.com/pages/components/2245H.pdf
Anyway, wouldn't you think this spec is significant?
Highest Recommended Crossover Frequency: 800 Hz
I mean, I'd figure they know what they are talking about if they recommend
800hz as the MAX crossover freq.
Its a LONG way from there to 2000Hz -
JBL 4645
09-24-2008, 05:34 AM
As opposed to going to JBLPRO and just reading the specs there?
http://www.jblpro.com/pages/components/2245h.htm
pointing to the brochure here:
http://www.jblpro.com/pages/components/2245H.pdf
Anyway, wouldn't you think this spec is significant?
Highest Recommended Crossover Frequency: 800 Hz
I mean, I'd figure they know what they are talking about if they recommend
800hz as the MAX crossover freq.
Its a LONG way from there to 2000Hz -
Yeah maybe for LF bass to mid range and HF horn housed on top of the enclosure.;)
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