With two drivers, how about a dipole sub? Not sure 2241s would work for that, and I've never heard one in operation, but they seem to be pretty compact.
With two drivers, how about a dipole sub? Not sure 2241s would work for that, and I've never heard one in operation, but they seem to be pretty compact.
I think that some of you are missing the point here:
"My thought was to build some house shaking 2-ways with large horn up top."
No one is talking about building a sub here and a 2245 running "all the way up to a horn" is just not going to do it.
Then get a 2240 which has the exact same basket as the 2245. It has Fs30, will cross at 600Hz no sweat and it has a light cone. ;-)
If cabinet volume is limited, then using woofers in an isobaric system will reduce cabinet size by half. But you need twice the amps. Nothing is free. ;-)
He wants bass and an extended range. The 2241H is the best 18" for the job, except perhaps the neodymium 18" which gets a bit more bass. I've been through the plots before I purchased my 2241Hs.
These are the WinISD plots for the three woofers in question. The yellow line is the 2245, the red is the 2241, and the green the 2240. As far as I can tell the 2240 is just a big, loud, lower midrange with volume and power handling being it redeeming values. These plots represent WinISDs "best" attempts at bass that the speaker can reproduce, regardless of cabinet size or porting, to produce the flattest response.
Hi toddalin,
I'm fully supportive of your approach since you entered the thread, regardless of the curves in post # 21 and some other things, since it tries to make something acceptable with what the "customer" HAS, instead of what he DOESN'T. Sablotny is in a particular situation which requires more help than simply the dump/replace driver approach...
I'll be back with more on my reasoning here and consequently why I support what you do. Keep the approach and position! There's two of us. Regards,
Richard
Wow. I am impressed by your plot. Three woofers that are flat from 100Hz and up... Just kidding ;-) But I don't think it reflects the real world. That being said. Any woofer can do anything if one is willing to heavily digitally "massage it"... The OP has a 2241, well let's have him do the experimentation by himself. And if comments from more experienced people is not wanted as mentioned by RMC just above, oh well. ;-)
BTW I once did some test with a 2241... Not impressed at all. Sure it can handle twice the power as a 2240, but that's probably because you need twice the power to get decent low bass. Just the same as its little brother, the 2226 which is well known to be a mid bass driver, not a woofer as we expect it... ;-)
Hi Toddalin and Sablotny,
RE Lee's fairy tale, the usual crap, no time to waste on that: he sure hasn't read nor understood post # 22.
I think the purpose of this site is to share info and provide help whenever possible and within the means of everyone (provider and "client").
Some folks here seem to be quite fast on the trigger, driver wise (i.e. kill it). If I can help Sablotny make an acceptable LF box, not necessarily ideal in view of constraints, I will though the "jury" may think otherwise. Trying first to "salvage or rescue" the drivers seems important, as he won't get reimbursed for these = money down the drain. Also important when its JBL drivers being discussed on a JBL stuff related site, and the member has requested suggestions to make things work. Dumping or scraping them he can do all by himself, he doesn't really need help for that.
Right from the start Sablotny admitted having made a mistake when ordering the drivers, and that there are concerns from spouse about box size. Fine for me, that's part of real life and of the challenge of working with constraints, like taking whats there.
I'm much more interested in trying to help him out of the ditch than making thumb up or down on the equipment. This is why I modeled a number of 2241H boxes for him so that he can assess the impact and help him make a choice.
Seems to me this site has an elitist tendency in its approaches. Looks like "audio snobbery", and it reminds me of what another member wrote in another thread not long ago about members giving too much importance to perfection and their reference system than really helping the younger generation or newbies who come here for help and know mostly MP3 sound on ear buds. Can't remember his Avatar and exact words but its something along these lines here.
2241H is basically a sound reinforcement driver (not really for sub), with all that comes with it, instead of a home hi-fi or a control room monitor driver (though tech sheet tries to salvage the latter aspect). These are different ball games. One emphasizes linearity and deeper bass, the other sensitivity and spl output at the expense of the former items.
I take it as it is trying to provide something helpful to the member, like Toddalin, rather than focus on what he should own or puchased, which would mean dumping working drivers he spent money on, plus spending more on others that fellows here won't pay for. Then lets try to make these work.
Sure doing it this way requires more time and effort. But I think that discarding the drivers doesn't really help him at all, it just means "you purchased the wrong thing" i.e. appears blaming vs helping him out.
Going back to the following, plus his stated context, its my guidance: "My question is: can I stuff these into smaller enclosures as a compromise? I know it would not be optimum, but using the woofers would seem to be better than not using them." He knows its not best but still better than nothing.
If the bass is deficient, then he can start with 2-3 boundary box placement to help increase VLF output, that is free bass boost, saving some EQ and associated amp power requirement.
So I support Toddalin's approach, which is also mine here, to try to make something with the drivers instead of nothing. I see this as more useful, relevant and cost-effective in the circumstances. We agree on the end result for somewhat different reasons, but some are complementary. Regards,
Richard
Subject to building a real enclosure for subjective assessment the OP may like the D.B. Keele 6th order boosted alignment with the 2241 woofer.
A bass reflex enclosure of 7cu ft 3 with 1 inch of fibre glass lining yields an f3 of 29 hertz (see curser window box readout) with the tuning of Fb = 26 and boost of 26 hertz (Q=2).
At full power the output is 128 db AT 26 hertz and 124 db at 40 hertz.
A large JBL 2384 wave guide and a suitable driver could be used down to a crossover frequency of 630 hertz. Theis wave guide is regarded as being particularly impressive from diy user reports.
The 2241H has a maximum recommended crossover frequency of 800 hertz
The boost for the woofer, horn and crossover for a bi amp system (for friendly diy ) can be applied with a DSP loudspeaker management system such as from DBX.
The reason l went for the above approach is the 2241H is not a hifi woofer. You can’t get any worthwhile bass extension that would be an expectation for relatively large enclosures in a domestic setting.
If the OP is a SE triode nerd with 2 Watts who only listens to acoustic or folk music he might be happy but otherwise it would sound loud but thin in the bass. It’s a pa woofer and with its efficiency requires a relatively large enclosure by domestic standard.
Good stuff Ian, thanks. I've got a pair of 811b horns I had stripped and re-powdercoated black, but larger waveguides that can cross over lower would be a better bet. DSP crossovers would seem to be a prefect match for this project with their flexibility. Just figuring out now if I want to dedicate my garage to the project or if I should hand off the 2241's to someone else.
Hello,
I too have a pair of 2241H’s on the shelf. The size of the required reflex enclosures puts me off a bit as well.
I am thinking that putting these drivers into closed 4.5 ft^3 boxes would be idea for a 2.1 system. The 2241 will be down only 3dB at 63Hz. Perhaps with just a little equalization and room gain in your small listening space at home no sub would be required.
Use what you have; add a sub sometime in the future if you must.
Thanks DT
Hi DT,
For the most part I totally agree with you, specially "Use what you have" and add a sub in the future.
But why settle for sealed box 4.5 cu.ft. F3 63 hz when better can easily be done according to my simulations in post # 7? Whether for your own 2241H or Sablotny's.
5 cu.ft vs 4.5 is pretty much the same cab size in my view. However, my 5 cu.ft simulation showed:
* 5 cu.ft., Fb 35 hz, F3 48 hz, ripple + 0.7 db @ 100 hz, Sv min. 41 sq. in., 2 X 5" vents (39.3 sq. in.), Lv 12.2"
So for half a cubic foot more or so (peanuts) you get F3 at 48 hz in vented. That's 15 hz lower bass with no sweat!!
Plus you get the benefit of vented- box increased efficiency with lower distortion due to vent work, more so when you mention EQing the low end on top of room gain. Why bother with closed box in this context?
Why not go for 5 cu.ft vented then?? With all due respect, that's the part I have some difficulty with. Regards,
Richard
Hello,
I agree that ½ cubic foot out of 5 is not going to be much difference either way.
Another option is to build the enclosures with a port(s) and tune to your prescribed resonance and also provide a plug or cap to seal the port(s) tight. Try it both ways; vented and closed.
My preference leans towards the tighter controlled bass of the sealed enclosure.
Added thought; 12dB boost at 35Hz for the sealed enclosure is flat down to 35Hz, not shabby.
Thanks DT
There are currently 1 users browsing this thread. (0 members and 1 guests)