Quick & Dirty 4430-Inspired Two-Ways Part II

[Hamilton]

Can't just throw 'em together, tho, and expect it to work worth a poop....

Zilboe, were you referring to using a 10 cu ft center cab for two 2118s?

[Zilch]

Zilboe, were you referring to using a 10 cu ft center cab for two 2118s?

Hampone, we expect to see full exposition of your killer "projects" in their own thread here in the very near future.

Complete with RTA results, of course.

[Oh, and JBL Monitor Blue grilles.... ]

[TimG]

How much were those 2352 horns, did you get them direct from JBL?

[Zilch]

How much were those 2352 horns, did you get them direct from JBL?

Hi, Tim.

Yup, I scored a chipped "B" stock pair. Factory list new is $306 apiece. I paid about 1/3 less.

Be aware, though, we have no confirmation of compatibility of these OA horns with the newer 1.5" driver phase plug. The horn flanges have to be drilled with a different bolt circle to mechanically accept these drivers. If there were an "A" version with factory mounting holes and something published about using these, I'd feel a bunch more comfortable about this presently unsupported combination.

It seems to work, sounds good, and measures well with the limited capabilities available here.

[Earl K]

Hi Zilch ( helping to "up" the post count , towards 1000 )

- I've been working out with PowerPoint. ( Ever since I realized it was effective as an export tool for .gif graphics . )

- Here's a collage of info available from other disparate sources / but now existing in a single graphic. ( OK, maybe the S5500 FR graphic is new / even though it must have been obtained here ) .

- The relevancy of this posting is mostly due to the 2-Way nature of the S5500 and it's associated "Prior-Art": network ( along with its' use of the 275nd ) .

- Also, since we were talking about impedance equalizers ( & GTs' use of them for 15 years ) / here's another early example .
- I believe the Vertical Scale for impedance is ; 10 ohms per darker horizontal line .
- I've included some questions & speculations within this graphic (mostly for my sake / due to my ADD, since I never get around to asking after them ).

- I've included the bio on Fancher Murray because he designed the 275nd .

regards

[Zilch]

Radian aluminum diaphragm with Mylar surround:

http://www.radianaudio.com/products/.../1245_1225.pdf

Here in 2425 on H3100 driven with N3100, reduced 3 dB with 6-Ohm L-Pad (S=1.75 Ohms, P=14.5 Ohms) kludged onto the driver. Impedance correcting LCR notch filter (0.16 mH, 30 uF, 10 Ohms) also in place at crossover input.

Compare response to earlier RTA curve with stock 2426H (bottom). It took several hours of break-in for the Radian to develop HF extension. "Bump" at 9 kHz adds "crispness" to their sound on these horns.

Yup, smoother sounding than stock titanium. Now $89 at Parts Express, counterbore recess in driver body made installation easy. No alignment required (though I checked with a sweep).

Crappy curve actually sounds good. Point is, expect a difference on swapping.

We'll get more definitive measurements in the planned 1" driver/diaphragm study using CLIO soon.

2426H subs for Mpingo disk (front).

[4313B]

Yup, smoother sounding than stock titanium. Now $89 at Parts Express, counterbore recess in driver body made installation easy. No alignment required (though I checked with a sweep).

Oh Ick! If I wanted Radian parts in my JBL's why would I buy JBL's in the first place? That's it Zilch, back you go on to my ignore list... for some stupid reason I took you off of it when David posted in this thread.

Let's change the title of this thread to "Quick & Dirty 4430 Wannabees Done Dirt Cheap".

[Mr. Widget]

We'll get more definitive measurements in the planned 1" driver/diaphragm study using CLIO soon.

Maybe you'll be able to set up a measurement area upstairs where you have more room. The early reflections in your "lab" will reduce the time window and thus the validity of the lower frequencies. It will be interesting to see how these various drivers and diaphragms combined with the various horns actually do plot once you are set up.


Widget

[Earl K]

Hi Zilch

- Could you post 2 more RTA shots of the N3100 driving just the 2426H (Ti )/H3100 ?
- ( One with the LCR impedance equalizer in place and the other shot without the LCR filter ). Put an 8 ohm dummy load on the woofer section of the network.
- I would think one might see the LCRs' effect manifested in the lower FR response of the horn , especially if you have available a higher resolution scale for your RTA .

Thanks <> EarlK

[Zilch]

If I wanted Radian parts in my JBL's why would I buy JBL's in the first place?

Now, Giskard, we're just lookin' for compatible aluminum diaphragms is all, which you, yourself, have stated you prefer.

D8R2421's at $244 apiece are not an option for many (if not most) users. At $89, these were worth testing, certainly.

It's easily seen they're not the same; not equivalent, even, at least in this setup.

[I'd bet you've tried 'em yourself, actually.... ]

The early reflections in your "lab" will reduce the time window and thus the validity of the lower frequencies.

Yeah, I'm kinda ignoring the LF for now. That big bump at ~630 Hz is appearing on all of the systems here, of late. A couple of weeks ago, the room was eatin' 200 Hz. Interestingly, if I short out all of the other woofers in the room, some of that anomalous stuff goes away.

It will be interesting to see how these various drivers and diaphragms combined with the various horns actually do plot once you are set up.

Ummmm, we're doin' that at YOUR lab, remember?

[Tell Giskard you wanna see the Radians too, please.... ]

[4313B]

Now, Giskard, we're just lookin' for compatible aluminum diaphragms is all. D8R2421's at $244 apiece are not an option for many (if not most) users. At $89, these were worth testing, certainly....

I'm sure all the other aftermarket parts people can buy are worth testing as well.

One is either up to the task of owning and caring for Altec and JBL loudspeaker systems and components or they are not.

[Zilch]

One is either up to the task of owning and caring for Altec and JBL loudspeaker systems and components or they are not.

We're doing the Aquaplas coated D8R275nd's too, as you know. Dusting some stock Ti's is also an option to achieve damping, though some here would be yellin' at me for doing "unsupported" Franken-stuff with that, too.

I'm not cheap, and I'm not trying to win anything. It's all good for tryin', yup....

[Mr. Widget]

Yeah, I'm kinda ignoring the LF for now. That big bump at ~630 Hz is appearing on all of the systems here, of late. A couple of weeks ago, the room was eatin' 200 Hz. Interestingly, if I short out all of the other woofers in the room, some of that anomalous stuff goes away.

I think you're missing my point. You will see what I am talking about once you get going with Clio. You will also be able to get very accurate and repeatable HF measurements, as long as the mic placement is reasonably precise.

Ummmm, we're doin' that at YOUR lab, remember?

I figured I could get out from under that since you are getting a set-up. How about a compromise... I'll come over once you have it up and running and I'll show you how the thing works and how to take accurate MLS measurements... it'll save you several days of fussing around with it.


Widget

[Zilch]

Could you post 2 more RTA shots of the N3100 driving just the 2426H (Ti )/H3100 ?

1) Without filter.
2) With filter.

2.5 dB per dotted line, twice the resolution I usually post.

My 6230 amp don't give a whit, looks like.

Lemme run the woofer, too ...

3) Without filter.
4) With filter.

Nada.... :dont-know

[Earl K]

Nada.... :dont-know

Yeh, thanks ! as you say, nothing to see there apart from some typical pink noise variations in the response .

I find the investment ( by JBL ) in those three added elements quite interesting to say the least / since one can't easily point to an obvious FR payoff .

Again, thanks for the effort .

<> EarlK