Subwoofer for hi-fi: 2242H vs 2245H.

[Doc Mark]

Greetings, Friends,

Well, my $30 2242H is going to have it's new dust cap, possibly today, and I'll soon be playing around with a box for it. Several of you have suggested, and it appears quite wisely, that the 2245H would actually be a much better choice for home hi-fi subwoofer use. So, I've been playing around with alignments for each woofer, and it appears that you may well be right.

I've been running graphs on the Linear Team site, and in most cases, the 2245H looks to give a flatter, more extended bass response, in similar cabinet size, than the 2242H. Hummmmmm......?????

I do not have, however, a 2245H against which I can compare the 2242H, which I DO have. So, in your collective opinions, should I dump my plans to use the 2242H for a hi-fi subwoofer, and replace it with a good 2245H? I could very probably sell the 2242H to someone who wants it for use in a more high power system than what I have in mind for home use. Or, if someone has a really good condition 2245H, and would rather have the 2242H, I might be open to a trade. Or, hell, I could just hang onto it, and use it for something else, "someday", and buy a good 2245H!

What do you think, my JBL Friends?? I want the best VLF sub I can get, for my intended purpose. My power will come from a Crown DC300A, in mono-mode, and we will very seldom require our system to really crank out the db's!! Should I stick with the 2242H, in an 8-10 cubic foot box, properly ported and EQ'ed, or go with the 2245H, in a similar-sized box, also properly ported? Thanks for any thoughts you might have on this! Take care, and God Bless!

Every Good Wish,
Doc

[pos]

I've been running graphs on the Linear Team site, and in most cases, the 2245H looks to give a flatter, more extended bass response, in similar cabinet size, than the 2242H. Hummmmmm......?????

Hi Doc

Don't let these simulations mislead you:
If you run a simulation with a similar box and tuning for the 2245H and 2242H keep in mind that the 2242H is 99dB/1W/1m whereas the 2245H is 95dB/1W/1m

If you look for SPL output you will see that infact the responses are quite similar below 80Hz, and that the 2242H rises to 99dB above that.

http://www.audioheritage.org/vbulletin/showpost.php?p=43846&postcount=3

That said, the response curve do not tell everything

[JBL 4645]

Hi Doc

Don't let these simulations mislead you:
If you run a simulation with a similar box and tuning for the 2245H and 2242H keep in mind that the 2242H is 99dB/1W/1m whereas the 2245H is 95dB/1W/1m

If you look for SPL output you will see that infact the responses are quite similar below 80Hz, and that the 2242H rises to 99dB above that.

http://www.audioheritage.org/vbulletin/showpost.php?p=43846&postcount=3

That said, the response curve do not tell everything

I think the 2245 off the top of my head is down 20Hz and was THX approved and they sounded and felt wicked with the original JBL THX specification at the Empire. I think the 2242 is 22Hz or 25Hz? It will still damage the home surroundings when played loud!:D

[johnaec]

You're really making this a lot more complicated than you need to. The speakers are designed for slightly different uses.

First, the main obvious difference is that the 2245 uses a foam surround, while the 2242 uses a corrugated one. Because of the greater compliance of the foam, it's able to more easily follow LF waveforms with accuracy, plus, it's not as stiff so its resonance frequency will be lower than the stiffer surround of the 2242. This means the 2245 is able to more accurately reproduce VLF than the 2242.

OK - so if the 2245 produces a little better VLF than the 2242, why even build the 2242? Mainly, because of live pro sound use. By using a corrugated surround, they lose a little bit of VLF, but there's no comparison in terms of reliability. When driving the 2245 and 2242 to concert sound levels, they foam surrounds just constantly wear out - they're not made for that kind of abuse. Hence the modifications to come up with speakers like the 2242, that are really made to take whatever you throw at them. That's why Scotty uses 2242's.

Fortunately, their fidelity is such that they can still be used for purposes other than pro sound.

So if you want the highest fidelity for home/studio use, the 2245 will give you a little more, but if you want something you'll never have to worry about, (with close to the same fidelity as the 2245), get the 2242.

That' my take, anyway...

John

[JBL 4645]

You need a large diy (MDF) enclosure kinder like the one that I have. It will give U.S.S. Enterprising impulse and warp factor 10 sound pressure! :applaud:


http://i233.photobucket.com/albums/ee15/Evolution3417/StarTrekthemotionpicturedeepsubb-4.jpg


http://i279.photobucket.com/albums/kk123/IndianaJones34/JBLBladeRunnerfivescreen.jpg


You're really making this a lot more complicated than you need to. The speakers are designed for slightly different uses.

First, the main obvious difference is that the 2245 uses a foam surround, while the 2242 uses a corrugated one. Because of the greater compliance of the foam, it's able to more easily follow LF waveforms with accuracy, plus, it's not as stiff so its resonance frequency will be lower than the stiffer surround of the 2242. This means the 2245 is able to more accurately reproduce VLF than the 2242.

OK - so if the 2245 produces a little better VLF than the 2242, why even build the 2242? Mainly, because of live pro sound use. By using a corrugated surround, they lose a little bit of VLF, but there's no comparison in terms of reliability. When driving the 2245 and 2242 to concert sound levels, they foam surrounds just constantly wear out - they're not made for that kind of abuse. Hence the modifications to come up with speakers like the 2242, that are really made to take whatever you throw at them. That's why Scotty uses 2242's.

Fortunately, their fidelity is such that they can still be used for purposes other than pro sound.

So if you want the highest fidelity for home/studio use, the 2245 will give you a little more, but if you want something you'll never have to worry about, (with close to the same fidelity as the 2245), get the 2242.

That' my take, anyway...

John

Interesting fact that was! But why, why, why, is JBL shipping out 18” subs with cloth ribbon surrounds today, if they know this fact? Only issue I have is having to replace the foam, yes it easy providing its done right, but what dog’s dinner it can be sometimes.

I heard that the JBL 4645 was busted in a few times at the Empire Leicester Square with one of the THX trailer introductions with its original 13KW JBL THX seems like a task then of getting behind the screen and replacing the damaged driver! The original set consisted of x8 JBL 4645.

I prefer cloth ribbon its far more robust over foam.

[4313B]

So, I've been playing around with alignments for each woofer, and it appears that you may well be right.Ya think!? :rotfl:

You're really making this a lot more complicated than you need to.From glancing at the myriad threads that have been started recently with respect to this and the L300's I'm guessing you're probably right.


The JBL Model 4645 and JBL Model S1S originally used the 2245H. If I remember correctly it was 8 cu ft tuned to 30 Hz. At some point JBL changed the tuning frequency of these boxes to 25 Hz. I think some models still used the 2245H at that time and the 2245H's started suffering excessive casualties. The 2242H became available and it could handle all the power and abuse the original 2245H could not. The 2242H is designed to be used in larger numbers where mutual coupling fills in the VLF region very nicely. It can still be used in pairs just like it is in the current S1S but the 2245H is arguably a bit better in that role providing it isn't overdriven. The easiest thing to do with a DIY S1S or 4645 box is to bolt a 2242H or 2245H into it and then use a BX63A if desired. The 25 Hz tuning frequency of the newer S1S and 4645 boxes are functionally equivalent to the old B460 box.

[JBL 4645]

I like to see pictures Doc because I like pictures I like to see some pictures of the JBL 2245 from many angles because that is hot sub bass when fitted in the right enclosure.:)

:useless:

I’ll show you a picture of my JBL 2240 if you show me your big huge 18” JBL 2245.

[toddalin]

Think W15GTI. You can get more LF extension in a box half the size of the 2245 and never worry about "overexcursion" or foam rot. Plus you can pick them up new for ~$250 (or less). ;)

[Doc Mark]

Greetings, Friends,

Thanks, very much, for that additional information! I know, it seems as if you are repeating such things over and over again, and I guess in some ways, you are! But, it is much appreciated, in any case.

I rather liken LH to my stove collecting site, on which I am heading for 7,000 posts, not too long from now. I've been collecting old brass kerosene, Coleman fuel, and alcohol stoves, and gathering spare parts, and learning how to rebuild them, since the late 1970's-early 1980's, and in all that time, I have made enough mistakes that I can help keep new "Stovies" from making those same ones! Yes, it sometimes feels like those of us with more experience are repeating the same old stuff, over and over again (sound familiar;)), but we have to remember that those folks that asked the questions are new, and do not have the vast experience (read that: haven't made enough mistakes, yet!), that some others of us have!! Sometimes, I think that, if I have to tell one more person how to remove and properly rebuild an NRV (non-return valve), I'll go out and kick someone!!! But, I have to remember that, to a new person, this rather simple and mundane task is extremely daunting, and quite scary!! If a mistake is made, not only will the stove malfunction, but severe injury, conflagration, and even DEATH, can result!!! :blink:

So, just like you more experienced folks here at LH, over at the stove site, we have to help those with less experience, to keep them safe, happy, and healthy. And, in truth, that's what we want to do, anyway, even if it seems boring at times. Without new folks learning about them, our old, and very "obsolete" backpacking and expedition stoves will slip even further into the collective unconscienceness of history, and before too long, nobody will know a thing about them. Same with thing JBL, as far as I'm concerned!

So, please bear with me, and I'll try not to tax your patience, too much! ;):) I haven't built an enclosure for a good many years, and I've NEVER actually used a computer to model performance, prior to building. I have alway sat down with some rudimentary test gear, my calculator, a pencil, and some paper, and worked out the alignments as best I could. Hey, most of the time, they came out fairly well, to tell the truth!! But, all this computer modeling is new, and somewhat scary to me, especially when I see something different, depending on which program is doing the work for you!! :blink:

JBL4645, as to photos, I have none of the 2242H, Mate. But, I promise, after I pick it up from Edgewound, which might be today, or early next week, I'll snap a few and post them here. Fair enough?! ;):D

Thanks again, to one and all, for your suggestions. Even if you think otherwise, I AM learning from your wise counsel, and hope to end up with something good when I am finally finished with these projects! Take care, and God Bless!

Every Good Wish,
Doc

[hjames]

Think W15GTI. You can get more LF extension in a box half the size of the 2245 and never worry about "overexcursion" or foam rot. Plus you can pick them up new for ~$250 (or less). ;)

Hmm cool - so - those look like some kinder Car speakers tho ...
Will they really play in the home?
Can I just stick one in my B380 for deeper sound?

[toddalin]

Hmm cool - so - those look like some kinder Car speakers tho ...
Will they really play in the home?
Can I just stick one in my B380 for deeper sound?


Yes, some kinder Car speaker... is that really a problem what the original intent was so long as it does the job?

Yes, they will play in your home, with authority, no less.

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/Woofers.jpg

http://www.largescaleonline.com/eimages/lsolpics/Team_Member_Pics/toddalin/center-2235-w15gti.jpg

Possibly, but recognize that the surround sticks out further than the 2235 in your cabinet and this could hit your grill. Also, the speaker is much deeper (note the first picture) so you need adequate space behind it. I added some standoffs for my grill.

You can run them at 12 ohms and need lots of power (500+ watts).

[Allanvh5150]

I was going to run W15gti's in my theartre, Alpine make one that is on a similar level as well. The JBL is about $1500 here! Not that money really make a difference but instead I installed 4 2235's, which cost about $300 for the lot. They arent as power hungry as "car subs" but then again, why would we put car subs in anything but our cars?:)

[toddalin]

They arent as power hungry as "car subs" but then again, why would we put car subs in anything but our cars?:)

:dont-know Maybe, because they work better in that range, can be put into a smaller cabinet, are more readily available, are cheaper, are almost indestructable, carry a longer warrantee, not as prone to sun fade and rot, never bottom out, and never get foam rot??? Seems logical to me.

[Allanvh5150]

I knew that would get a bite out of you.:D
I do love the car subs as well but only in my car.
I will post some pics later of where my subs are positioned. They are both huge cabinets that are burried in the wall which just happens to be the downstairs roofspace.

[toddalin]

I was going to run W15gti's in my theartre, Alpine make one that is on a similar level as well. The JBL is about $1500 here! Not that money really make a difference but instead I installed 4 2235's, which cost about $300 for the lot. They arent as power hungry as "car subs" but then again, why would we put car subs in anything but our cars?:)


OT, but do you know the Sullivan's in Christchurch? They now have my '70 Corvette roadster that I restored, as well as a '63 split window. Maybe you've seen my old roadster running around town. Its Donneybrook Green with green interior and a white convertable top. If you see them, say hi to them for me. :bouncy:

Todd

[robertbartsch]

I'm using a 2242H in a large 10 sq ft. vented cab with a Dayton 500 watt sub amp. In a home setting, you can't ask for more. On demand - it feels like it could move the house from the foundation.

During the plannning phase, I was considering a smaller box and smaller amp but the advice here was not to do this.

Anyway, the unit is downward firing about 10 inches off the floor. (The idea for the downfiring sub was obtained from a "Klip-horn" sub. I own)

The cab has roller casters and the power amp is mounted in the cab but it is a tad too big for my taste - estetically speaking.

If you are considering an amp that has equalization built in, I would suggest that you consider a smaller box - if huge boxes are not your thing!

I'm not real keen on separate subs but this one is the best of the bunch. Most others I have tried over the years are localized. You can definately hear where this one is located but much less so than other subs I have known. Unfortunately, much of today's ULF program material on DVDs, 5.1, 7.1 tracks is recorded on the sub only track.

I just bought two blown 2240 carcasses but I have no idea what these will ultimately become in the future.

[4313B]

Think W15GTI. You can get more LF extension in a box half the size of the 2245 and never worry about "overexcursion" or foam rot. Plus you can pick them up new for ~$250 (or less). ;)Alot of people just don't like high Q subwoofers... I know you can't seem to understand this but the point is, JBL would drop that puppy into the HB5000 or 1500 Array instead of a W1500H in a New York minute if they knew it would do the job they were after.

You are right, the W15Gti are much cheaper and easier to obtain but so are alot of other things in life... and I suspect alot of forum users would love them.

The main selling point of the larger eighteens is that they can move a much larger amount of air with much less effort. If one has the requisite room they are quite fascinating. That's why JBL hasn't replaced every other VLF transducer with the W15GTi... it is not the be all, end all that you would apparently like it to be.

During the plannning phase, I was considering a smaller box and smaller amp but the advice here was not to do this.I personally did not care for the sound of the 6 cu ft EQ'd box for the 2242H. I think JBL called it the S1S-EX.

I just bought two blown 2240 carcasses but I have no idea what these will ultimately become in the future.Hopefully they will be reconed as 2245H's and used in 4345 clones. :p

[mikebake]

:spin:

[toddalin]

Alot of people just don't like high Q subwoofers... I know you can't seem to understand this but the point is, JBL would drop that puppy into the HB5000 or 1500 Array instead of a W1500H in a New York minute if they knew it would do the job they were after.

You are right, the W15Gti are much cheaper and easier to obtain but so are alot of other things in life...

The main selling point of the larger eighteens is that they can move a much larger amount of air with much less effort. If one has the requisite room they are quite fascinating. That's why JBL hasn't replaced every other VLF transducer with the W15GTi... it is not the be all, end all that you would apparently like it to be.
I personally did not care for the sound of the 6 cu ft EQ'd box for the 2242H. I think JBL called it the S1S-EX.

When you say people don't like "high Q" subs, I assume that you mean these to be "one note wonders." (Maybe you need to define your terms and say why this is a bad thing?)

But in the home enviroment in a proper enclosure, I find that the frequency response is more linear under 80 Hz than a 2235, far more linear under 40 Hz, and a world of difference in the 20-30 Hz range in similar enclosures. This was documented here in the past. No need to get into it again.

[4313B]

When you say people don't like "high Q" subs, I assume that you mean these to be "one note wonders." (Maybe you need to define your terms and say why this is a bad thing?)Everyone who knows what they are doing with these things knows exactly what I mean. No need to define anything. And no, high Q doesn't mean "one note wonder" in any sense of the word. JBL has traditionally used low Q transducers that fit very well into quasi third order alignments. Occasionally they use higher Q transducers for sealed boxes or to create a certain response such as the high Q driver in the old L100. I've long suspected that you had a massive gap in your understanding of high performance loudspeaker systems and that is probably why you continue to peddle these automotive subwoofers. Seriously though, I am sick of going over and over this so I hope going forward everyone will buy W15GTi's and use them profusely. All that really matters is that JBL sell product and if that product is in the form of W15GTi's so be it. Going forward I will stay out of these endless subwoofer threads.

But in the home enviroment in a proper enclosure, I find that the frequency response is more linear under 80 Hz than a 2235, far more linear under 40 Hz, and a world of difference in the 20-30 Hz range in similar enclosures.As long as you're satisfied that's all that matters.
:spin:Yep, pretty much and I'm excusing myself from it.

[robertbartsch]

Well, personally, I would prefer to design a high fidelity system without a separate sub or subs. Since the Hollywood wizards have effecively eliminated that option, we are all "stuck" with the problem of re-creating very low frequency sound in our home theaters and music systems.

Not to rant, but while were at it, I don't care too much for the rediculous amount of sound tracks they have in 5.1 and 7.1 systems. Ask youself this: are all these tracks really necessary?

If I was not a skeptic, I would assume multi-track material was created by the manufacturors to specifically induce us to purchase more amps, more speakers, more recorded material and other such gadgets.

By-the-way, I need a bigger house now that my home theater equipment has morphed to unmanageable proportions. I suppose this is one way to stimulate the economy.

[Doc Mark]

Evening, All,

Well, I'm finally back from running errands, both up here, and also down the mountain. Besides the mundane stuff, I also got to make a quick stop at Edgewound's place, because my three woofers were all ready to go!! YAHOO!! :bouncy::bouncy::applaud:

I must tell you, very honestly, that Edgewound's work is better than any other I've yet seen! In almost 30 years as a professional musician, I've seen tons of recones, refoams, and most of the other things that such shops do. But, when I picked up my two 128H woofers for my new 4411's, and my 2242H, they all, pretty much, looked brand spanking new!!! :blink::D Ken is a true artist at this business, and his work was worth every bit of the charge he asked for it!! I can hardly wait to get the 4411's up and running, but it may have to wait until next week, as I am WAAAAAY behind in my work, and that must always come first. No, really, it should. Now, stop it, I mean it.... this time!! ;);) Ken takes extra special care to do things that I've never seen at ANY other Authorized Service Center, JBL, or otherwise. His meticulous craftsmanship is very apparent in the finished product, too. Can you get this sort of work done for less? Not on our life, my Friends! Yes, you can PAY less, but after seeing Ken's work, I guarantee that you will not get the kind of professional work that I got for my money. Again, worth every penny!! Thanks, Edgewound, for your very professional attitude, attention to detail, and meticulous work!! Well done, my Friend, and MUCH appreciated!! Take care, and God Bless!

Every Good Wish,
Doc

[Doc Mark]

Howdy, Mates,

OK, back to the subwoofer project. I have decided to go ahead with the 2242H, as that is what I already own, and now is not a good time to be spending more money. So, with that in mind, I note that JBL recommends a 10 cubic foot enclosure for this woofer, tuned to 40HZ! Odd, to me, especially when they are selling the 4645C, which is an 8 cubic foot enclosure, tuned to 25HZ, with that same woofer!

When looking at alignments in Linear Team, both the 10 foot box, and the 8 foot box seem to have good and bad points. What do you think, Folks? I'm tempted to go with the 8 footer, and try to duplicate the 4645C. But, something about that 10 foot box is "calling me", and I'd appreciate your thoughts and comments on this. Thanks, very much, and God Bless!

Every Good Wish,
Doc (who remembers his promise to take photos of the 2242H and post them here, and will try to do that tomorrow!) ;)

[Doc Mark]

(snip) I'm using a 2242H in a large 10 sq ft. vented cab with a Dayton 500 watt sub amp. In a home setting, you can't ask for more. On demand - it feels like it could move the house from the foundation.

Robert,

To which frequency did you tune your 10 cubic foot box, please? Thanks, and God Bless!

Every Good Wish,
Doc

[robertbartsch]

Doc:
I don't recall the tuning now. I got the views of several folks here about the size of box and the port, etc. since I was not too interested in playing with the specialized software at the time.

Most wives that I have known do not like big sub boxes for a home system, as you probably know. Frankly, the difference between an 8 and 10 foot box is not that much in an average sized living room.

In the planning phase, you should consider the amp too. If the amp has equalization you have some more flexibility, I suppose. But again, 8 or 10 is a toss up, so you may want to error on extra large size.

I prefer new electronics for the specific task at hand to avoid future hastles including trying to repair old electronic components. The Dayton sub amp at 500 watts into 8 ohms has worked well so far. It runs cool as ice with no special ventalation or forced cooling.

The downward firing sub was a very good idea in retrospect since you can avoid building a grill to fit the box. The sub box with a downward firing woof and no grill is less obtrusive looking in a home setting if that is a concern with a picky spouce.

[Rusnzha]

The 2242h will make you very happy, this is a promise. You might consider a Velodyne SMS-1 to use in conjunction with it. I am using one with my 2241h and it is nearly flat down to the lower limits of hearing. A good healthy amp (500 watts or more) will assure you of plenty of headroom in this situation.

[Doc Mark]

Greetings, All,

Many thanks, as always, for your thoughts and suggestions! Much appreciated!

OK, today, I took a break from work, and snapped a couple of pics of the 2242H, and my 128H woofers, showing Edgewound's great work on them! So, without further delay, and so I can return to work, here they are!

Take care, and God Bless!

Every Good Wish,
Doc

[Doc Mark]

Hey,

Forgot you can only do five at a time! Oops! Here are a few more...

Doc

[boputnam]

That' my take, anyway...Good post, John.


Alot of people just don't like high Q subwoofers... Count me in that lot.


The main selling point of the larger eighteens is that they can move a much larger amount of air with much less effort. If one has the requisite room they are quite fascinating. That is so true. I marvel at the efficiency, response and tonality of the 2245 even at extremely low gain - we're talking maybe 46dBA (Leq ;)). Amazing.


...something about that 10 foot box is "calling me", and I'd appreciate your thoughts and comments on this. Dood, if you have room for 8ft3, then you likely have room for 10ft3. Do not skimp on cabinet volume, if you don't need to. Like 4313B advised, these 18's move a lot of air. It's best to keep them happy... :)

[Doc Mark]

Hello, Bo,

Thanks for that thought, and I do believe you are right in your comments. I had pretty much settled on the 10ft3, but after reading Greg's old article in SR, am now wondering if I should shoot the moon, and go all the way to a 12ft3 box?!! I will have to think on that some more, and see how it looks on the Linear Team site. But, after I came to grips with a 10ft3 box, such a thing most certainly seems to offer more than the 8. Thanks, again, and God Bless!

Every Good Wish,
Doc

[spkrman57]

http://audioheritage.org/vbulletin/showthread.php?t=4845&highlight=cubic




Howdy, Mates,

OK, back to the subwoofer project. I have decided to go ahead with the 2242H, as that is what I already own, and now is not a good time to be spending more money. So, with that in mind, I note that JBL recommends a 10 cubic foot enclosure for this woofer, tuned to 40HZ! Odd, to me, especially when they are selling the 4645C, which is an 8 cubic foot enclosure, tuned to 25HZ, with that same woofer!

When looking at alignments in Linear Team, both the 10 foot box, and the 8 foot box seem to have good and bad points. What do you think, Folks? I'm tempted to go with the 8 footer, and try to duplicate the 4645C. But, something about that 10 foot box is "calling me", and I'd appreciate your thoughts and comments on this. Thanks, very much, and God Bless!

Every Good Wish,
Doc (who remembers his promise to take photos of the 2242H and post them here, and will try to do that tomorrow!) ;)

[Doc Mark]

Hey, Spkrman57,

Thanks for that one! After seeing that thread, and also running the performance graphs on Linear Team, I've decided that I am best served with the 12ft3 box, tuned as Greg Timbers suggested in his outstanding subwoofer article. Since I already have a very good 2242H on hand, which I don't really believe was ever even mounted in a cabinet, I'm going to use that one and see how I like it. If I find it lacking in detail and subtlety, then I'll find a 2245H and use it in the same cabinet, as per Greg Timbers. Don't really see how I can lose, no matter which way it turns out, eh?! The only change I will make in Greg's original design, is in the placement of the 18" driver. I will be mounting the 2242H on the front baffle, instead of on the end, as that will better fit into either of the two locations in which I will be placing this enclosure.

The cool thing is, that I can use this big subwoofer with my L300's, with the 4333's, or with a 4-way system that will also be in the offing! Outstanding options, as far as I'm concerned!

Now, to get some time to actually build this giant and put it to use!! ;):D:bouncy: Take care, and God Bless!

Every Good Wish,
Doc

[spkrman57]

4313B put alot of effort into that thread and I had always found it useful(still do!!!);)

Ron

[JBL 4645]

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=35191&stc=1&d=1226188870

You bugger you! You, I said you bugger you. What he said bugger you? Yes he said you bugger you.:D

That’s my clean version of Derek & Clive LOL :D

http://userserve-ak.last.fm/serve/252/66918.jpg

Damn I like that JBL 2242 sub bass really tasty yummy delicious. :applaud:

Are you using any loudspeaker crossover management system with this set-up? It’s the word now (LCMS)! The word!:)

[4313B]

Don't really see how I can lose, no matter which way it turns out, eh?!The 2242H is a low compliance woofer, it doesn't need that huge volume. You can build it and then proclaim all over the Internet that is rocks your world but it really isn't best practice. In that size box with that 25 Hz tuning frequency the 2245H has roughly 4.5 dB greater output.

[spkrman57]

I think that says it all for the 2242!

Ron

[Doc Mark]

The 2242H is a low compliance woofer, it doesn't need that huge volume. You can build it and then proclaim all over the Internet that is rocks your world but it really isn't best practice. In that size box with that 25 Hz tuning frequency the 2245H has roughly 4.5 dB greater output.

Good Morning, 4313B, and All,

Thanks, as aways, for your thoughts and comments on this project. I guess I'm more than a little confused by "the graphs". When I compare the 2242H in a 12ft3 box, tuned to 25HZ, I am seeing a -6db point of around 25 HZ. When I look at the graph of the 2242H in a 9ft3 box, tuned to 30 HZ, I see a -6db point of around 32HZ, or so. From that, it appears I'd be getting a bit more solid bass extension by going for the larger box, and slightly deeper tuning. Am I wrong about that, and if so, why?

I fully understand that the 2242H was made to really shine in high SPL situations, and in clusters, and that the 2245H is probably better for the project I have in mind. However, I don't have a 2245H at my disposal, and at this time do not see the funds to procure one coming my way for a while. So, given that, and given that I already have a 2242H, and given that Mr. Timbers recommended a 12ft3 box, tuned to 25HZ for the 2245H, it seems to me that going with the bigger box will give me acceptable results with the 2242H, and later, should I chance upon a very nice 2245H, then I can simply swap them out, and have a subwoofer that really performs as such a system is supposed to! Again, am I wrong about that, and if so, why? The 2242H may give me what I am seeking, which is a bit more bass extension than the L300's can offer. 25HZ seems better than 32HZ, given that the L300's extend to around 35HZ, right? In truth, I am really happy with what the bass respone that the L300's offer us, but if a little more can be had, why not go for it?

Thanks, very much, as always, for your thoughts and comments on all this. As I've written before, I realize that all this is old hat to folks like you, but your experience seems vast, and for those of us without the wherewithal for in depth testing, it is crucial to know as much as we can before beginning such a project. Take care, and God Bless!

Every Good Wish,
Doc

[4313B]

I think I might understand where your confusion might be coming from. Because JBL used the 2242H in the same box as the 2245H, 8.0 cubic feet tuned to 25Hz, you thought perhaps that they were interchangeable in the larger volume as well?

In reality 8 cu ft is pretty large to a 2242H, its Vas is something like 9 cu ft. In contrast, 8 cu ft is really small to a 2245H with its Vas of something like 29 cu ft. The group delay and transient response of a 2242H in a 12 cu ft box looks pretty bad. JBL actually has another subwoofer that uses the 2242H and I believe that volume is on the order of 6 cu ft. That should give you an idea of where the 2242H likes to be.

I wouldn't waste my time and lumber building a 12 cu ft box for a 2242H regardless of what may happen in the future. I would build a nice 8 cu ft box tuned to 25 Hz and possibly apply the 25 Hz bump filter if required. Forget about the 2245H, it isn't the driver you have. Use the driver you have in the box it requires. You don't use a phillips head screwdriver to remove slot head screws do you?

Any kind of decent dedicated sub is going to slaughter your L300's on the bottom end. That's what bandwidth limiting does. A single 4645C should murder your L300's and leave plenty of forensic evidence in the process.

[mikebake]

A single 4645C should murder your L300's and leave plenty of forensic evidence in the process.
:applaud:

[Doc Mark]

Hi, 4313B,

Ahhh, comes the dawn! I am beginning to understand why this has been confusing to me, thanks to your last comments. Thanks very much for helping to clear away some of my confusion. Yes, I was thinking that both woofers "could" be interchangable in the larger box, as well as the 8ft3 enclosure. You are right in the Vas of the 2242H, as it's 10ft3.

I am looking for the type of performance that the B460 would add to our systems, both the L300's, and any future experimental goodies, like a 4-way system + sub, which I guess will actually be a 5-way system (18 [sub] + 15 + 10 + CD/Horn + slot tweeter, all electronically crossed over).

And, as you correctly surmise, since I already have the 2242H, and only paid $30 for it, I was hoping to use that for my project. I see, now, that it will offer me "something", but not really the true performance I was seeking. Will the addition of a 2242H, in an 8ft3 cabinet, be "good enough"? I do not know. But, it's probably a good place to start, in that I can try to reproduce a clone of the 4645C system, and see how I like it.

If it is not satisfactory, I can replace the 2242H with a 2245H, somewhere down the line, and retune the cabinet as necessary, and end up with a clone B460. That makes sense to me, and seems like a fun and educational experience, which is part of why I am interested in doing all this in the first place! ;):D

Thanks, again, for your thoughts on all this! Much appreciated! I'll post further comments as I actually get into the project, and begin to make sawdust. Take care, and God Bless!

Every Good Wish,
Doc

[spkrman57]

Look at the last post on this thread showing one of the 9 cu ft boxes made by 4313B which I used for awhile:

http://audioheritage.org/vbulletin/showthread.php?t=4845&highlight=cubic&page=3

I found that bandwidth limited below 80hz these subs (2242H) were actually TOO much for my 12' x 16' living room and were capable of permanent hearing damage if listened to at high levels.

If you built the 8 or 9 cu ft boxes for the 2242's, I don't think you would be disappointed. When you mentioned that response in the mid 30hz range did not seem adequate I must point out that they did actually did work below that effortlessly.

Don't take specs alone as a rule of thumb and you should be quite happy!

Just my 2 cents worth here.

Regards, Ron






Hi, 4313B,

Ahhh, comes the dawn! I am beginning to understand why this has been confusing to me, thanks to your last comments. Thanks very much for helping to clear away some of my confusion. Yes, I was thinking that both woofers "could" be interchangable in the larger box, as well as the 8ft3 enclosure. You are right in the Vas of the 2242H, as it's 10ft3.

I am looking for the type of performance that the B460 would add to our systems, both the L300's, and any future experimental goodies, like a 4-way system + sub, which I guess will actually be a 5-way system (18 [sub] + 15 + 10 + CD/Horn + slot tweeter, all electronically crossed over).

And, as you correctly surmise, since I already have the 2242H, and only paid $30 for it, I was hoping to use that for my project. I see, now, that it will offer me "something", but not really the true performance I was seeking. Will the addition of a 2242H, in an 8ft3 cabinet, be "good enough"? I do not know. But, it's probably a good place to start, in that I can try to reproduce a clone of the 4645C system, and see how I like it.

If it is not satisfactory, I can replace the 2242H with a 2245H, somewhere down the line, and retune the cabinet as necessary, and end up with a clone B460. That makes sense to me, and seems like a fun and educational experience, which is part of why I am interested in doing all this in the first place! ;):D

Thanks, again, for your thoughts on all this! Much appreciated! I'll post further comments as I actually get into the project, and begin to make sawdust. Take care, and God Bless!

Every Good Wish,
Doc

[Jakob]

Hi Doc! Have to congratulate You on taking this route. Once you've tried an 18 inch there is no way back. I run a pair of 8 cu ft boxes with the cousin of the 2442, the 2243, and even at very high levels when flowerpots crack and paintings fall from the walls, You can hardly see the cones moving :) Be prepared to move the sub around in Your room in the beginning to get the right sound and gain, especially if not using any room calibrating tools. Have a nice vibrating winter!

Regards: Jakob

[toddalin]

Be prepared to move the sub around in Your room in the beginning to get the right sound and gain, especially if not using any room calibrating tools. Have a nice vibrating winter!

Regards: Jakob

Not to hijack the thread, but there is a way around this. The effect is the same if you place the sub in the seating position and simply move your ears (or mic) around the room to find the best position for the sub.

Of course getting a 10 cubic foot box to sit on you sofa in your position may be a little harder. ;)

[Doc Mark]

Evening, Jakob and Todd, and All,

Jakob, thanks, very much! I'm looking forward to messing with this, but also have other JBL projects on the list, too, including those great 4333's I got from Grumpy!! Yeah, man!! But, I have a feeling that, with a decent 18" JBL as a subwoofer, I will be "won over" fairly easily to the need for such a thing! ;):D Thanks, again, for your nice words of support and encouragement!

Todd, I actually have an RTA and calibrated microphone, and even though it's probably not up to the standards you need in your job, it will work just fine for me in this application, me thinks. It's a Soundcraftsmen AS-1000 Scan-alyzer. I'll most certainly use it, especially when setting up the Ashly XR-4001 electronic crossover. Thanks for the suggestion of moving the sub, but I was wondering if it had to cross it's legs, whilst sitting on the couch, or would the invalidate the test??!! :blink::blink::D:bouncy: ;) Take care, and God Bless!

Every Good Wish,
Doc

[Doc Mark]

Spkrman57,

Thanks for your additional comments and suggestions, too. Since you've already trod this path, and with the help of 4313B, and others, I can see you've gained some experience and insight into what I can expect to hear, I appreciate your sharing this with me. Thanks, too, to 4313B for putting all this into proper perspective, and for making sense of it all!! Much appreciate, one and all!! :applaud::D Take care, and God Bless!

Every Good Wish,
Doc

[16hz lover]

To expand on and revive this thread, I'm toying with the idea of using (2) 18" woofers, either 2242 or 2245 models in a 19 cu ft box, which I would like to have with a divider in the middle so that each driver has 9.5 cu ft. of space behind it, and I wanted to use a rectangular port for each driver.Tuned as low as possible as I would be using it with a 60 hz crossover. I do not have any software to model this up and would love to hear your suggestions on which is the more suitable driver. I would be driving these with a Crown K2 amp. I'm looking for maximum output at the lowest frequency ( aren't we all ):p
Thanks in advance

[Loren42]

To expand on and revive this thread, I'm toying with the idea of using (2) 18" woofers, either 2242 or 2245 models in a 19 cu ft box, which I would like to have with a divider in the middle so that each driver has 9.5 cu ft. of space behind it, and I wanted to use a rectangular port for each driver.Tuned as low as possible as I would be using it with a 60 hz crossover. I do not have any software to model this up and would love to hear your suggestions on which is the more suitable driver. I would be driving these with a Crown K2 amp. I'm looking for maximum output at the lowest frequency ( aren't we all ):p
Thanks in advance

Will this be an assisted or unassisted design?

Here are some of my observations:

1) I would keep the port round instead of rectangular. Rectangular ports are hard to change compared to round and offer no sonic advantages. Round ports are easier to flare since those components already exist at places like Madisound and Parts Express.

2) The tuned frequency for a vented enclosure is a set of trade offs. The lower you tune the port the higher up the frequency band the bass response begins to dive downward. Raising the tuned frequency higher will flatten out the response, but you get a steeper roll off after the tuned frequency.

3) 9.5 cubic feet per driver will probably be a little small for optimal low end response.

If you want, I can model that in BassBox Pro and show you exactly what I mean.

I have no idea which speaker poses a better driver for your cause. The 2242 handles a lot more power, but its Fs is 35 Hz, versus the 2245, which has a Fs of 20 Hz.

Can someone chime in and tell me why the 2245 would not be the better driver for HiFi?

[spkrman57]

2245 best low end response in the home.

2242 most output available without destroying the drivers!

Ron sends...

[grumpy]

There have been many post comparing the JBL 18" drivers... some referenced in
this thread. In the case of 2242 or 2245 in 9.5ft3 volume (presuming you'll add a few
dB if doubling up), and choosing 22Hz tuning as an example, you can see limitations and
responses (w/ 60Hz L-R LPF) comparing the two at their max Pe (300w and 800w) in
the accompanying plots (grab a free copy of WinISD to play with):

[Loren42]

Okay. I did some comparison plots to give you some ideas.

The traces are:

Color Volume Fb F3
Red 9.5 18 47.5
Yel 9.5 24 40.3
Grn 15 20.3 43.8
Cyan 15 16 50.4

Volume is in cubic feet and Fb and F3 are in Hz.

Fb is the frequency that the cabinet is tuned to.
F3 is the -3 dB point.

Your best sound tends to be with the lowest F3 as far as bass response goes. The higher the F3, the quicker bass rolls off.



http://www.mdbq.net/2245_Curves.jpg

[16hz lover]

Wow, after seeing those curves, it looks like I'm gonna have trouble getting a good flat output at 25hz.:( I thought having a 19cu ft box in my room with 2-18" woofers in it was gonna break the good China. Why does Grumpy's response curves look so good compared to the steep roll off or Lorens? And what it the green curve at the bottom Grumpy? Are both of those the 2242?

[Loren42]

Wow, after seeing those curves, it looks like I'm gonna have trouble getting a good flat output at 25hz.:( I thought having a 19cu ft box in my room with 2-18" woofers in it was gonna break the good China. Why does Grumpy's response curves look so good compared to the steep roll off or Lorens? And what it the green curve at the bottom Grumpy? Are both of those the 2242?

I don't know why the difference. Grumpy?

You can always pump up the bass with an active EQ. This is called an assisted design. JBL does this as well.

However, let's ask a few questions of yourself. First, what are you trying to accomplish? Why?

I can see two ways of looking at it. There are more, but let's explore these two first.

One goal is to create a subwoofer that meets some design criteria. Let's say you want flat response down to 20Hz. Well, the best way to do that is to cast away any prejudices and explore every possible way to generate audio down to that level. I might look at this link (http://www.drmarksays.com/?p=25) to do that.

Wait! There isn't a JBL in there anywhere. Right, but if you want a specific criteria, then JBL might not be the right tool.

Now, on the other hand, let's say the project requirement is all about getting the most out of a JBL 2245. That's another horse and a different challenge. It would be fun to see how you could maximize that driver in a specific cabinet. The end result may not be as good as another caugh-caugh manufacture's driver, but that wasn't the point, was it?

Let's say that the latter is what you want and you play with a JBL 18. The next question is what compromises must you make? Cabinet size is one of those. In your case you may have a limit. How do you work around that limit? Can you think of something a little out of the box? Maybe a corner horn? Maybe something else?

So, tell me what you are after and what are the limitations for your requirements and the next steps will come pretty easily.

[grumpy]

Grumpy?I don't see that there is much difference. Loren's FR plots are normalized,
mine are at specific power levels, and I included max-power/xmax-limit
info in the left plot (Green 2242H, Red 2245H). Plot on the right ignores
max-power/xmax-limit, but it wouldn't be crazy far off (just note in the
left plot where the system will max out).

I didn't bother plotting above 200Hz as that wasn't the stated area of interest
(and gets wonky with cheap modeling software anyway).

Note that thus far, room gain has not been mentioned and will affect things
greatly.

Both are capable of scooting the good china off of the shelf.

Opinon -> 2245H seems to be a more articulate driver, having tried a pair
of each... one per 8ft3 JBL theater cab. 2242H isn't far behind in this regard but
can take b-loads more power and be happy (as has been stated a number
of times). My take? If you want to shake things as violently as possible, go
with the 2242H and buy a -big- amp. If you want to hear as much music
as possible (hearing 'into' the music ... pitch definition, instrument identification,
etc...) I'd suggest the 2245H's as being a worthy choice. I'd also
suggest with the 2245's that you might want to go bigger with the cabs
if you want to see "how low, can you go".

Availability and cost may also steer you one way or the other.

Cool that Loren can help you! :)

[16hz lover]

I don't know why the difference. Grumpy?

You can always pump up the bass with an active EQ. This is called an assisted design. JBL does this as well. I was planning on using a 31 band eq with the sub to add some boost as needed.

However, let's ask a few questions of yourself. First, what are you trying to accomplish? Why? I was looking for 120 @ 20hz in my room. Why???? Because I want to recreate the actual sounds at realistic levels in my room...isn't that the purpose of a stereo to begin with?:D

I can see two ways of looking at it. There are more, but let's explore these two first.

One goal is to create a subwoofer that meets some design criteria. Let's say you want flat response down to 20Hz. Well, the best way to do that is to cast away any prejudices and explore every possible way to generate audio down to that level. I might look at this link (http://www.drmarksays.com/?p=25) to do that. I've been the car stereo driver route before and was not impressed, as 99% of all the drivers are very inefficient and they depend on car cabin gain. I went last week to a guys house who had the almighty Maelstrom 18" sub driver (although it was in a sealed box):(, and it has 33mm of linear travel. I proceeded to burn up his voice coil with my demo disc(which has happened numerous times). He had a 2400 watt amp that ended up clipping, which did the voice coil in. Those sealed box designs just keep asking for more and more power until the woofer goes up in smoke due to the amplifier running out of juice.

Wait! There isn't a JBL in there anywhere. Right, but if you want a specific criteria, then JBL might not be the right tool.

Now, on the other hand, let's say the project requirement is all about getting the most out of a JBL 2245. That's another horse and a different challenge. It would be fun to see how you could maximize that driver in a specific cabinet. The end result may not be as good as another caugh-caugh manufacture's driver, but that wasn't the point, was it?

Let's say that the latter is what you want and you play with a JBL 18. The next question is what compromises must you make? Cabinet size is one of those. In your case you may have a limit. How do you work around that limit? Can you think of something a little out of the box? Maybe a corner horn? Maybe something else? Yes, I am restricted to a box 96" long and about a 23" cube as my corners will be used up with 4 horn loaded bass bins(2 per corner), each bin having (2) 15" drivers....I think I've got the coveted mid-bass thing all covered.;)

So, tell me what you are after and what are the limitations for your requirements and the next steps will come pretty easily. See information supplied above. Thanks.

[4313B]

I have no idea which speaker poses a better driver for your cause. The 2242 handles a lot more power, but its Fs is 35 Hz, versus the 2245, which has a Fs of 20 Hz.The 2242H is designed to be used in multiples (mutual coupling) in large venues where maximum, ultra low distortion, low frequency output is required.

JBL also used it to replace the 2245H in the ubiquitous 4645 and S1S subwoofers when the 2245H was retired. These days one might also want to look at the 2269H.

Can someone chime in and tell me why the 2245 would not be the better driver for HiFi?The 2245H was half the cost of the 2242H and is arguably the better choice for home hifi applications if you can find or build one. We've beaten this dead horse well past the point of exhaustion.

2245H or 2242H in a 4645, S1S or B460 box with or without a 25 Hz bump filter such as the BX63/BX63A and it's a done deal. If one really likes bigger boxes for some reason then build them bigger instead. The 2242H won't like it as much and the 2245H will. Whatever...

Until some of you guys actual build this stuff and get some experience in various venues and configurations under your belts you're just wasting everyone's time dreaming and blogging about what could be.

[BMWCCA]

Because I want to recreate the actual sounds at realistic levels in my room...isn't that the purpose of a stereo to begin with?:DI'm not sure the purpose of "stereo" was to actually reproduce the sound levels of today's live concerts, but "high-fidelity" was intended to re-create the live music experience at home. And for that, I'm pretty confident my 2245Hs in their 9-ft boxes (4345) do that pretty well by faithfully and effortlessly reproducing low frequencies even at low volume—something I value much more than their ability to destroy my ears at SPLs of 120-dB and higher.

[Ducatista47]

I'm not sure the purpose of "stereo" was to actually reproduce the sound levels of today's live concerts, but "high-fidelity" was intended to re-create the live music experience at home. And for that, I'm pretty confident my 2245Hs in their 9-ft boxes (4345) do that pretty well by faithfully and effortlessly reproducing low frequencies even at low volume—something I value much more than their ability to destroy my ears at SPLs of 120-dB and higher.

Nice answer, and it does bring up the question. Why don't we put all the questions asked here into two categories - at least in our heads. Is a desired playback SPL for a proposed system (speaker capability or amp power or both) about high fidelity enjoyment? Or is it about reproducing concert level when anyone at that concert (or theater) in those seats should be wearing earplugs? I have to believe that the latter is about nostalgia or an "easily entertained" personality, but not high fidelity.

No need to figure out a quality solution for how to destroy someone's hearing. A Yamaha or Peavey SR rig will do nicely, and chances are it will sound more like what they heard in the first place than a nice JBL or Altec system. There goes half the DIY and three quarters of the amplifier discussions. :D

Clark

[16hz lover]

Nice answer, and it does bring up the question. Why don't we put all the questions asked here into two categories - at least in our heads. Is a desired playback SPL for a proposed system (speaker capability or amp power or both) about high fidelity enjoyment? Or is it about reproducing concert level when anyone at that concert in those seats should be wearing earplugs? I have to believe that the latter is about nostalgia or an "easily entertained" personality, but not high fidelity.

No need to figure out a quality solution for how to destroy someone's hearing. A Yamaha or Peavey SR rig will do nicely, and chances are it will sound more like what they heard in the first place than a nice JBL or Altec system. There goes half the DIY and three quarters of the amplifier discussions. :D

I had a feeling I would end up getting a response like these....don't get me wrong now, I appreciate your participation, but I'm talking about the ability for the system to reproduce a loud low transient, most things in movies(explosions,cannon shots, etc) or an orchestral drum tuned to 22 hz, japanese kodo drum, etc. is just that...a transient, not sustained rock concert levels. I don't want to have hearing damage anymore than you guys do. Most all hi-fi- systems are incapable of reproducing the very low frequencies, or a set of drums in the room, due to their limited spl capabilities and/or frequency limitations.
As a drummer, and trumpet player, (Orchestral, Big Bands, etc.) I have spent enough time in close proximity of percussion to know what things sound like as those two instruments are the loudest in the band.
If I had the room, I would surely design a very large horn system that would be flat to 20hz and be 110db/eff. , but I'm squeezed for space with my 19cuft box. Most all audio enthusiasts I have known have never heard a true full range system with true dynamic capabilities.

If you were to bring a blind person in the listening area, would they be convinced that what they were hearing was an actual event happening in the room? For most all the systems out there, the answer is NO:(

Unfortunately, I spend way too much of my time scouring the web for information, in hope of saving myself time and money building speakers I don't need to build. :banghead: So your useful suggestions are appreciated.:applaud:

[jcrobso]

To expand on and revive this thread, I'm toying with the idea of using (2) 18" woofers, either 2242 or 2245 models in a 19 cu ft box, which I would like to have with a divider in the middle so that each driver has 9.5 cu ft. of space behind it, and I wanted to use a rectangular port for each driver.Tuned as low as possible as I would be using it with a 60 hz crossover. I do not have any software to model this up and would love to hear your suggestions on which is the more suitable driver. I would be driving these with a Crown K2 amp. I'm looking for maximum output at the lowest frequency ( aren't we all ):p
Thanks in advance

Lowest note on the piano 27hz. Only a BIG pipe organ can get an octave lower or about 14hz. My 5 string bass goes to 31hz. In general there is no music blow 27hz, except for thumps and explosions on DVDs. If you have room for 19cu ft box great! But make sure you do tune it correctly!!
I have see some subs where this was not done and the cones flop around, makes me want to :barf:
Report back when you have finished.:) John

[jcrobso]

since you thinking about BIG boxes get a pair like this! They WILL rock your world!:D John
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=370178151468

[57BELAIRE]

http://i233.photobucket.com/albums/ee15/Evolution3417/StarTrekthemotionpicturedeepsubb-4.jpg


http://i279.photobucket.com/albums/kk123/IndianaJones34/JBLBladeRunnerfivescreen.jpg



Interesting fact that was! But why, why, why, is JBL shipping out 18” subs with cloth ribbon surrounds today, if they know this fact? Only issue I have is having to replace the foam, yes it easy providing its done right, but what dog’s dinner it can be sometimes.

I heard that the JBL 4645 was busted in a few times at the Empire Leicester Square with one of the THX trailer introductions with its original 13KW JBL THX seems like a task then of getting behind the screen and replacing the damaged driver! The original set consisted of x8 JBL 4645.

I prefer cloth ribbon its far more robust over foam.

[/quote

I prefer cloth over foam also and after having to refoam my 136H
for the third time I opted for double roll treated cloth instead...
well, you'd have thought I burned down the local church.

Some of the "purists" here castigated me with no mercy,,,in fact
the kindest remark was I had created "Frankenwoofers" :blah:

I think JBL's Achilles heel has always been the use of foam in their products (surrounds, grilles, damping...it doesn't last!

[4313B]

I think JBL's Achilles heel has always been the use of foam in their products (surrounds, grilles, damping...it doesn't last!The best surround material was Lans-a-loy. Unfortunately it was a warranty nightmare.

I guess we'll find out how long these newer rubber surrounds last...

[16hz lover]

Lowest note on the piano 27hz. Only a BIG pipe organ can get an octave lower or about 14hz. My 5 string bass goes to 31hz. In general there is no music blow 27hz, except for thumps and explosions on DVDs. If you have room for 19cu ft box great! But make sure you do tune it correctly!!
I have see some subs where this was not done and the cones flop around, makes me want to :barf:
Report back when you have finished.:) John

Yep, I worked in the pipe organ business for 7 years and Low C on a 32ft stop is 16hz fundamental. There is a piece by Bach which the Low C is held for over 30 seconds. I have a nice collection of music which has notes in the low 20's. You are correct in that most music doesn't contain anything near that, but then I'm not "normal" either.:blink:

[Allanvh5150]

How long does everyone expect the foam surrounds to last? Paper, cloth or foam, they all wear out but with foam it becomes very apparent when the foam falls out on the floor.....I still have original srrounds on my L86's and I have used 2245's in proffesional situations and the foam has lasted well in excess of 5 years. It is a very simple task to replace the foam and takes less than one hour per driver. How long do the tyres last on your car?

Allan.

[Allanvh5150]

Lowest note on the piano 27hz. Only a BIG pipe organ can get an octave lower or about 14hz. My 5 string bass goes to 31hz. In general there is no music blow 27hz, except for thumps and explosions on DVDs. If you have room for 19cu ft box great! But make sure you do tune it correctly!!
I have see some subs where this was not done and the cones flop around, makes me want to :barf:
Report back when you have finished.:) John

There are a couple of instruments that go lower than 10Hz. Do a search for "sub-contrabass clarinet". In the normal world though there isnt much below 40Hz. Alot of the LFE tracks are done with subharmonic generators whereby the bass frequencies are prcessed and dropped and octave or two below the original. As with most of the things we see on movies these days the sound is just as fake.

Allan.

P.S. Eathquakes go well below 10Hz......:blink:

[16hz lover]

since you thinking about BIG boxes get a pair like this! They WILL rock your world!:D John
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=370178151468
I have only room for a 23x23x96 box:(

[jcrobso]

I have a set of D140F with the original cones and cloth surrounds, they still sound great.:) john

[jcrobso]

There are a couple of instruments that go lower than 10Hz. Do a search for "sub-contrabass clarinet". In the normal world though there isn't much below 40Hz. A lot of the LFE tracks are done with subharmonic generators whereby the bass frequencies are processed and dropped and octave or two below the original. As with most of the things we see on movies these days the sound is just as fake.

Allan.

P.S. Earthquakes go well below 10Hz......:blink:

The original concept was music. Yes, non musical sounds can be very low.
My bass amp has a setting that will create an octave lower note that the one I'm playing. If I get the mix right it sounds like I have 10 string bass, similar to the sound of a 12 string guitar. If this works when I play the low B(31hz) I have no idea, I don't have any speakers that will do 16hz.:(

I did some checking some really, really big pipe organs have 64' pipe that will do 8hz. Keep in mind that the pipe IS 64' long! and about 12~16'" in diameter. Many times a 32' long wooden pipe with the end closed is used. The wave travels down the pipe hits the end and bounces back, total distance traveled is 64'. Yes there are comprises everywhere. What ever bass I get from my speakers I would rather have it be clean than crappy supper lows.. John

[57BELAIRE]

While working at Radio City Music Hall I was able to get an
upclose and personal experience with their magnificent pipe organ.

The longest pipe measured 2 stories and could be felt
from the dressing room as a rumble similar to an earthquake...now that's bass! :D

[JBL 4645]

I prefer cloth over foam also and after having to refoam my 136H
for the third time I opted for double roll treated cloth instead...
well, you'd have thought I burned down the local church.

Some of the "purists" here castigated me with no mercy,,,in fact
the kindest remark was I had created "Frankenwoofers" :blah:

I think JBL's Achilles heel has always been the use of foam in their products (surrounds, grilles, damping...it doesn't last!

You’re the work of the devil Satan him or herself. Burned down the church LOL :rotfl:
http://videodetective.com/photos/030/00128533_.jpg

I have something else on my mind that I’m sure has been talked about, only trouble is what keywords do I use to search for the thread if it does exist?

Frequency VS amplifier VS sub VS listening distance?

[JBL 4645]

While working at Radio City Music Hall I was able to get an
upclose and personal experience with their magnificent pipe organ.

The longest pipe measured 2 stories and could be felt
from the dressing room as a rumble similar to an earthquake...now that's bass! :D

I recall seeing on the internet a sub bass speaker that had long pipe kinder like that…excuse me Bose cannon wave, now you can attack me. :D

Not sure if I can find the article again as I stumbled across it on Google image I think a few years ago. The designer mentioned it had huge wave of air that would blow trousers from a given distance.:bouncy:


Edit: No its not this one but WTF now that is bit over the top, how in the hell are you suppose to fit that in the living room?:rotfl:

That has got to be at least 30 feet? Correcting 12 feet I’m waiting for the site to load the page up.

http://fle33.com/public/images/stories/Projects/Audio/DSCF5466.JPG

BASS CANNON
http://fle33.com/public/index.php?option=com_content&task=view&id=3&Itemid=2

[Valentin]

well i have 2 b460 cabinets with 2242h and just fine for hifi

[Ducatista47]

I had a feeling I would end up getting a response like these....don't get me wrong now, I appreciate your participation, but I'm talking about the ability for the system to reproduce a loud low transient, most things in movies(explosions,cannon shots, etc) or an orchestral drum tuned to 22 hz, japanese kodo drum, etc. is just that...a transient, not sustained rock concert levels.
I was speaking generally. I certainly did not intend to pose the question to any individual person. I hope no personal offense was taken.

Getting a speaker to reproduce very low frequencies in a musical way is only part of the battle. Recordings of musical material that actually capture that information and present it in home media are pretty scarce. The soundtracks of motion pictures, on the other hand, are rife with low information because it was synthesized, not recorded, in most cases.

If you can find suitable recordings, the greatest sacrifice a listener has to make is the sheer monstrosity of any system that will play it. The transducer, power and projection requirements climb so rapidly once you get below about 30hz. Everything gets so large and needs so much power. Home theater is one thing but high fidelity music containing 16 or even 8 hz is one tough nut to crack at home.

The quality is even more elusive than the basic technical problems. I have given up on ever hearing the rolling, seemingly omnipresent tones of a live string double bass done perfectly through a stereo rig, and that is not nearly as low as some of what you would like to hear properly reproduced. Even when the tones are technically being reproduced, the directionality and feel is all wrong. Multichannel does not seem to help.

Your blind man test is certainly a challenge when it comes to deep bass. I hope someone succeeds at some point. Maybe it will be you!

Clark

[JBL 4645]

I tweaked the diy JBL 4645 over and over and over last night or was it the night before haven’t tired the new settings yet, might try later in the day to see where it can or can not go.

I can’t lower the frequency response below 20Hz I can place filter with variable Q to squeeze or tighten up for narrow and cut the range down, but I’m still left with peak in the 10Hz range.

Also I blocked up all three ports to reduce some port air flow noise.

I’m not sure if this will present some order of strain on the JBL or demand more power I’m only at 300 watts bridge mode with Alesis RA300.

[JBL 4645]

I’ve just made a few short silent videos as the camera is picture only with video motion only.

I’ll format the videos load them up on youtube that will show the in-room frequency response A & B one with FBQ2496 parametric EQ OFF and ON.

Film is Star Trek IV The Voyage Home (1986) the one with the whales, the frequency response is fascinating. :bouncy:

Chapter 6 Warp speed Mr. Sulu
Time is taken from 32 minutes 29 seconds

I’ll post them when they have finished uploading.

[JBL 4645]

An in-room frequency response of Star Trek IV The Voyage Home (1986) the one with the whales.

Here I’ve stretched the limit diy JBL 4645 as far as I can possibly take it, as I need to know where she can or can’t go in terms of frequency response and SPL db max with the new FBQ2496 parametric EQ settings that took me several hours a few nights ago.

Star Trek IV spectrumlab FBQ2496 OFF
http://www.youtube.com/watch?v=4cMExPnnq6Q&feature=channel_page (http://www.youtube.com/watch?v=4cMExPnnq6Q&feature=channel_page)

Star Trek IV spectrumlab FBQ2496 ON
http://www.youtube.com/watch?v=jeHTmkiYp54&feature=channel_page (http://www.youtube.com/watch?v=jeHTmkiYp54&feature=channel_page)

The new EQ is still pending testing at realistic levels while noting barograph display on Alesis RA300 SPL db level and frequency response on spectrumlab. One thing I don’t want is clipping and I might tailor each film to fit within the size of image VS room.

The sub bass extension is next on the testing grounds to stretch it further than before. One thing I don’t have is barograph display on the Eltax A-12R so I’d have to use instincts and common sense. I really dislike active subs no barograph display no clipping LED, that’s just not on.

I do have the LED barograph display on the Behringer FBQ2496 for input monitoring of channel A LFE.1 track channel B sub bass extension LCRS.

Anyway note the frequency response with OFF and then ON the response is much flatter with less peaks in the 30Hz to 40Hz range. The video is bit smeary I apologize for the poor digital quality.

I must say this diy JBL 4645 has been very dependable over the 11 years and I’m only just starting to explore it further.

[JBL 4645]

Red Alert JBL is on Red Alert!

I’ve just noticed some heavy excursion and have eased off on the, peddle so to speck. Looks like I’d have to go over the figures again as it was really intensifying has the bird of pry got nearer and nearer to the sun.

It’s that damn peak down within 10Hz range, but it felt good.:p

[JBL 4645]

I’ve readjusted the placement of the microphone from the back of the sofa to in front of sofa which is 4 feet there a few dips.

This is looks kinder natural thou I’d have to run the same test sequence from Star Trek again and see if she holds together. She’s breaking up captain! LOL

[Valentin]

you are also forgetting the room

if you have a big room you may get a better room gain at lower freq

if your room is not big enough you will not have any room gain at the lower registers and too much gain at higher bass register

at these freq the room rules what we hear nor the speaker


there is also the question of loudness contour so 85 db at 1khz would mean about 110db at 25hz for them to be equal and that's mean a lot of power and air moving and all that to have bad room and screw things up with some peaks an deeps at tremendous power levels at higher frequencies that screw thing up

[JBL 4645]

So I’ve noticed its too bad isn’t that I have small room that isn’t even near the width of average cinema. But we keep trying like fools, don’t we. :D

[Eaulive]

Hey,

Forgot you can only do five at a time! Oops! Here are a few more...

Doc

The dustcap seam on this 2242 is flawless! I did my share of recones in my life but I don't think I ever achieved that kind of precision.

I know it does not affect the sound but still, great job!:applaud:

[Doc Mark]

Hi, Eaulive,

Thank you, very much! Like you, I think this particular 2242 is a fine one. I still have not had time to figure out my hum problems in the stereo, nor why my Ashly 4001 crossover doesn't seem to be as "seamless" as I'd like it to be. But, the 2242 is mounted in the JBL 4645 cabinet I got from Grumpy, and is ready to do, whenever I figure out the other stuff. Someday..... Thanks, again, for your nice comment, and God Bless!

Every Good Wish,
Doc

[lgvenable]

Doc
Are you suffering from ground loop hum? I resolved all ground loop issues on my system with the use of a isolation transformer to supply the system; as well as going to balanced i/o from the pre-amp to the amps (from unbalanced RCA to balanced AES/BEU on the amps).

The isolation transformer was a singel phase Square D 15KVA. I supplied power to the primary (240/120) via a 60 amp breaker from my main supply breaker box w/6 ga wire. I grounded the transformer box to the box and ground of the primary breaker box.
I then established a new ground (#2) for the secondary (120/240) and did three circuits 20A off the transformer to the wall where I'm installing the amps (12 installed).

Between this and the balanced connections, there is absolutely zero hum. Until this all I could do was put Behringer:blink:HD400 hum destroyers between each amp and my old Denon 3806 pre-amp unit RCA-outs.

Now the new Integra (Onkyo) DHC80.1 the output is perfect, and absolutely hum free.

I cant say how many things I did to eliminate hum, many suggested by well meaning forum members. However, a sound engineer I'm working with in the Evansville area showed me his mobil isolation power transformer and explained what I needed to do...voila...hum free.

Our ground loop issues on the sound system at our church were even worse; aggravated by the presence of AC dimmers in the lights. The same solution there resolved the issue there too, which was much much worse than I had ever had at home. ;). It was however considerably $$$ since I had to use a 3 phase 208 primary to a 120/240 secondary.

Good luck.

Larry
Larry

[Doc Mark]

Good Morning, Larry,

Thanks, very much, for that information. I think you sent me a PM with that same info, and again, this is much appreciated! I'm not ready to up grade our power to 60 Amp, however, and running new wire is out of the question, at least for now. We have too many other home upgrading projects that have to take precedence at this time. I've been replacing toilets, painting walls, re-grouting shower tiles, and other such fun stuff, for a while, now, with many more such projects on the list! :blink::bouncy: So, upgrading the wiring and power to the house will have to wait, I'm afraid. But, again, many thanks for the information. I will save it in my "important info" file, and put it to good use when time permits. Take care, and God Bless!

Every Good Wish,
Doc

[Eaulive]

Good Morning, Larry,

Thanks, very much, for that information. I think you sent me a PM with that same info, and again, this is much appreciated! I'm not ready to up grade our power to 60 Amp, however, and running new wire is out of the question, at least for now. We have too many other home upgrading projects that have to take precedence at this time. I've been replacing toilets, painting walls, re-grouting shower tiles, and other such fun stuff, for a while, now, with many more such projects on the list! :blink::bouncy: So, upgrading the wiring and power to the house will have to wait, I'm afraid. But, again, many thanks for the information. I will save it in my "important info" file, and put it to good use when time permits. Take care, and God Bless!

Every Good Wish,
Doc

Basic rule of thumb for hums and ground loops: have all the equipment at the same neutral and ground potential.
You can do this by:

1) Connecting ALL your interconnected equipment to the same power source.
2) Adding a heavy guage ground wire between all your device's chassis, with a good low resistance connection. and connect it also to the ground lead of the power inlet (the only one you should use as specified in #1)
3) Ground the entrance of the cable TV or satellite coax to the same grounding point, a couple of feet before it enters your equipment. Do the same with all conections to the outside world.

Remember, hum is caused by AC current travelling on the shields of the RCA, coaxial or any interconnecting wire in your setup.
In an unbalanced setup, the shield is the return path for the signal and the slightest foreign current that travels along will be heard, unlike a balanced connection where the shield is not part of the return signal, only the two inner conductors.
If you deviate the current caused by potential difference between your devices through an external, lower resistance conductor, you will most likely eliminate this hum.

I repeat, ZERO curent flow on the interconnects shields other than your music! Potential differences, if unavoidable should be channeled through external, low resistance paths.

Changing the cheap RCA cables to better ones WILL NOT solve your problem, the current is still travelling on them!


Good luck.

[Doc Mark]

Good Morning, Eaulive,

Thank you, very much, for your additional informaton! Much appreciated. I will add this info to my "important information" file, and when time permits, will use it in my experimentation on this problem.

As far back as I can remember, I've heard "some" hum in my Hi Fi systems, over the years. Most of the time, it's been so slight as not to bother me. But, when trying to hook up my current system (mostly H/K stuff) to the new Ashly XR4001 crossover (made in China), the hum was horrible and rendered the system not enjoyable!

Once my home projects are finished, I will have much more time to dig into this hum/noise problem, and I do very much look forward to sussing it all out, and getting our system hum-free! Thanks, again, and God Bless!

Every Good Wish,
Doc

[grumpy]

another link on hum/buzz problems:
http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz

(I'd change the diagnostic order and unplug any RF cable coming into the
house, first... as that is often the culprit)

If you have cable, but not a satellite/dish system (which may require a DC
pass-through), these are useful (and not crap), once your system is properly
grounded to begin with:

good price on isolator:
http://www.markertek.com/Video-Equipment/Video-Processors/Video-Noise-Hum-Elimination/Jensen-Transformers/VRD-1FF.xhtml

[Eaulive]

(I'd change the diagnostic order and unplug any RF cable coming into the
house, first... as that is often the culprit)

It is indeed, cable TV lines are terrible for this and often overlooked.

[Doc Mark]

Hey, Grumpy,

Thanks for that additional info! I've filed it, and will begin where you suggest, when I get to all this. Your fix is simple, and easily diagnosed, so that's a good place to begin.

On a completely different topic: I found another fairly good barbeque place. I'd been going to Lucille's, after you turned me on to that place, and like it quite a bit. Then, I stopped in at a place called "Famous Dave's", and it, too, is a pretty good place, for a chain restaurant. Ever been there? Another of our favorite places is "Woodranch", which has, in SB's and my opinion, the very best barbequed chicked we've ever had in a restaurant. Sorry to get off topic, but I'm hungry, and when I saw your post, Grumpy, I remembered our Lucille's visit a while back! :D Take care, and God Bless!

Every Good Wish,
Doc

[lgvenable]

hey doc,
I used a 2245H in my DIY sub; 600 wpc @ 8 ohm = 25 HZ. If you decide to build your own, I'll send the excel file if you pm & want it. I built a 12ft3 cabinet however, a box within a box w/additional fir 2x4 bracing.

It makes for some kind of bass!!! and weighs 228lbs.

I'm using a driverack260 to equalize both it and an SR4719A.

Larry

[Doc Mark]

Evening, Larry,

WOW!! That's some sub you've created, Sir!! I'll bet it pumps out the bass, when it's called upon to do that task!! I appreciate your kind offer of the box plans, but I'm hoping that the 4645 cabinet with my 2242H in it, will do what I want done. First, I have to make time to tackle that hum problem. Several good folks here at LH have offered outstanding suggestions for helping to track it all done, as have you, and I'm really thinking that I can find and kill that problem, when I have the time to do it. The huge box of your sub, would be wasted on the 2242, as it is not designed to work well in those big boxes. If I ever end up with a nice pair of 2245's, which I someday hope to do, then such a large box as yours will really be perfect for that superlative woofer! Thanks, again, for your kind offer, Larry. I'd love to hear that sub, one of these days! Take care, and God Bless!

Every Good Wish,
Doc

[Titanium Dome]

Doc, if you ever decide that 2242 is not the right driver for you, let me know. Based on common preference, most folks here favor the 2245 in a big box, so that might be the way to go. I'm planning a home for orphaned 2242 drivers, the poor second cousins of the 2245. Here they can wait out their final days in casual play while their well-regarded kin thump themselves into oblivion.

Now you let me know, hear? :D

[JBL 4645]

hey doc,
I used a 2245H in my DIY sub; 600 wpc @ 8 ohm = 25 HZ. If you decide to build your own, I'll send the excel file if you pm & want it. I built a 12ft3 cabinet however, a box within a box w/additional fir 2x4 bracing.

It makes for some kind of bass!!! and weighs 228lbs.

I'm using a driverack260 to equalize both it and an SR4719A.

Larry

Twin ports kinder like 4645B that has twin ports angled. Are these ports angled in the same way or just straight for a few inches inside the enclosure?

[Doc Mark]

Doc, if you ever decide that 2242 is not the right driver for you, let me know. Based on common preference, most folks here favor the 2245 in a big box, so that might be the way to go. I'm planning a home for orphaned 2242 drivers, the poor second cousins of the 2245. Here they can wait out their final days in casual play while their well-regarded kin thump themselves into oblivion.

Now you let me know, hear? :D

Hey, TD,

Very kind of your, Sir, and much appreciated! ;):D However, my main reason for wanting to score a nice pair of 2245's, is that I would use them in cloning a JBL 4-way, like BMWCC, 4313B, and others here at LH, have done. So, even if I get the 2245's, I have a feeling that the 2242 will have a home here in our mountains, for a good long time to come. But, just in case I change my mind, I will definitely keep your kind offer in mind, Sir! ;) Take care, and God Bless!

Every Good Wish,
Doc (who still loves his $30 2242, and for that price, might pick up another one..... IF someone wanted to sell him one for that price!!);):D:bouncy: