2225h, 2425j 2405h (077)

[seeker]

Hi all!

I am new to this forum and new to JBL... I was at a frien's house and heared his newly bought L300 Summit DIY copies....... I was really surprized to hear such clarity in the midrange, crisp and transparent top and tight bottom......
Anyway, I figured, maybe I could build myself something simular that isn't that big but yet good enough! In my room, where I sit, I have like 6-10 db raise at 30-50Hz and therefore looked upon woofers with a bit higher fs. I liked the sound of the 15" woofers in the L300 but realized that it wasn't for me, too big cabinet and too deep in terms of Hz.

I went to ebay etc. and came up (bought) with the following drivers:
2405h - 077 8Ohm with the prism (former jubal)
2425j
2225h

I will by horns (perhaps H91) and lenses to that.
I could change diaphrams 16 to 8 or vice vers

Now to my question:
Do you have any suggestions regarding crossovers horns lenses or boxes?
It would be prefferable to use standard crossovers (or just the schematics) from JBL but it's not a must! I would imagine that the JBL technicians has made a great job developing those crossovers....

Best regards
Patrik

[macaroonie]

You might want to have a look at this ------

http://www.audioheritage.org/vbullet...building+build


Its kind of in your zone.

[seeker]

Wow that was an interesting thread.... Will dig into that deeper later on for the buliding part!

What was your thoughts around the choise of crossover? Going active could be something for me to because I have the parts. Rather weak amplifiers though (Active home from Hypex). But I think that I will have a go at a passive crossover.

Do you know what differs from your and my woofers?
What are you driving the speakers with?
What are your impression of the speakrs now?
Do you still have them as they were?

Are there anyone else with this setup?
Which crossovers could I choose from (IBM Parts) and what modifications do I then have to do? changing diphrams?

/Patrik

[richluvsound]

Hi seeker,

it would be worthwhile having the 2225 reconed to 2235 .
2225 wont go low enough . If you need 2425's I can help - I have a pair with brandnew aquaplased dia that are just sitting here. Where are you in this big bad world ?

Rich

[macaroonie]

I know its quite a long thread but spend the time and plough through it and the parallel thread ' backyard box building '. Most of your questions are answered in there somewhere.
I would suggest that you go active if you have small kit amps for two reasons. One, the demands on each amp are significantly reduced because you do not suffer the insertion losses that occur with a passive network.
Two, given that you have at least two of these amps the cost of ramping up to the six ch. that are required is not high. I would suggest that one of these hypex units will not really be adequate to run the full system, and the cost of upgrading the amp to something more suitable will most likely cost more than more kits. Granted you still have to get an electronic x/o. Tons to chose from or build your own if you feel up to it.
Here is another link for you. http://www.jblproservice.com/pdf/M-S...onics/M553.pdf PS Rich is right about the recone but no need to do that yet you got some boxes to build. 2370 horn will get you there cheaply or my man in San Francisco will tell you about a suitable waveguide that you can use.
Zilch is the name and you will be needing him for your grill cloth requisites.
All the info you will need is here somewhere or if you get stuck just ask.
Good luck

[seeker]

Hi!

richluvsound: I already have the drivers I'm afraid. Thanks anyway!
But I am not so sure that the deeper bass won't be sufficient enough because I will have the speakers close to the wall behind them. Also I will sit close to the wall behind myself...... This will create a boost of, in the region, 6-10 db at 30-50Hz. The speaker box will also be slite larger than recommended, further extend the bass.

macaroonie: The active crossovers and amps are 3-way active with 3x65W in 8 Ohms per speaker....... I know it's not much so I will try it but I don't beleve in it.

/Patrik

[seeker]

Is there anyone else that perhaps has input regarding sutable crossovers ?

Also a sutable horn and lens..... Was thinking about H91??

/Patrik

[richluvsound]

Seeker,

coral make good copies of both 2307 (h 91 ) and 2308 lens. ebay is your best bet. There is a set set on German ebay.

I suggested a recone for 2 reasons. 2235 is
far more efficient than the 2225 pa woof- better suited to low level listening.If you want to clone the original crossover , then stick to original component spec. If you want to stick with 2225 then you'll have to redisign the crossover.

Rich

[seeker]

richluvsound: Do you mean the original crossover to L300?
One question though, What does it mean when JBL shows on the schematics that you should take the signal from the middle (AS IT LOOKS) of the coil...?
From the posts that I have read here it dousn't matter if I have 8 ohm 077 when it comes to the crossover values..?

I will check the horn from coral Thanks! Germany --> Sweden is not that far!

/Patrik

[macaroonie]

JBL used that tapped coil quite a lot in the good old days but it is not an off the shelf item. Somewhere in this forum there is a post that has it measured etc but much easier than that, here is a post from 4313B that re works the crossover and does not use that split coil

http://audioheritage.org/vbulletin/s...42&postcount=3

[matsj]

Technovox have 4 2307 for 400 svenska styck and maybe he have the 2308 lins also. Recone your 2225 to 2235 at LN högtalarservice for a lot better sound.
Where in Sweden do you live Patrik ?
Make a L300 look a like and you have a good start.

mats

[seeker]

Hi!

matsj: I live in Gothenburg and I don't know if you are the same mats that I am bying the bass and midrange drivers from but one thing is defenetly clear, you stole the L300 from a friend of mine, just in front of his nose.... ;-) That seller did not no what the value was!!

As I can see you all (some of you) think that I should recone the 2225 but I am not as sure of that as some of you are.... I can get really good bass from speakers that have their fs at -6 db at 50Hz in my room and in my listening position.......... Of course I will definetly give the original 2225 a try and go from there!!

Will the value (in terms of $) of the drivers be lower if I recone them?

Also hat do you think of the combination 077 8ohm, 2425 16 ohm - H91 or equal and lens , and the woofer 2225 or 2235? could it be something successful? I haven't seen anyone here at the forum with this combo.

/Patrik

[richluvsound]

Seeker,


your lucky that the 2225 basket is one of the very few that will take 2235 kit.

I think you answered your own question regarding your proposed combo.

The guys here know their stuff and I'd be inclined to follow them. There are

current and ex-employees from JBL that post here.... This is the Mecca !

The 2235 is one of JBL's most copied designs. Check the spec on the usher studio 15 . Only the Chinese copy crap !

Rich

[matsj]

Sorry for the L300 . No i´m not the same mats. I think you bought the stuff in småland right ?
I think you are on the right way.

2235h is for "hifi" and 2225 are more for "Pa".

There aint so many horns for 2425, but don´t look for the 2370.

mats

[speakerdave]

I used some 2225H's in some 4333a's briefly while the 2231's were being refoamed and I could not wait to hear the speakers doing something!, anything!

It was evident that the low bass was missing, and the midrange transition from the woofer did not work with the stock crossover. When the 2231's were ready I popped them in, and those two problems were fixed, but it was also clear that I had lost a good deal of snap and slam in the upper bass, which I do like.

So, as I see you are apparently set on using your 2225's, I will share this experience with you, but unfortunately I cannot advise you on how to adjust the crossover. You may be correct about thinking the 2225 will work well in your room, but it could also be the case that copying the L300 exactly and moderating your room mode some other way, may in the end be easier.

Regards,

David