Quick & Dirty 4430-Inspired Two-Ways Part II

[Robh3606]

"However, I believe we can all agree that it's extremely difficult, if not impossible, to do this without the appropriate measurement tools.

It's apparent in this thread and others here that a simple RTA can carry the endeavor a very long way, indeed, and it certainly expedites the process."

Hello Zilch

Yes it does help things. Yes, no tools and you are going no where fast. I am looking into CLIO as well so there could be a bunch of us by the new year. I am itching to start building again but want a better tool than the RTA. Not that I can't appreciate what it's capable of, sure has served me well over the years. It's just time to move on to something better. Maybe we could start our own clinic in a thread. We can all learn together.


Rob

[Zilch]

Thank you, Rob.

I must say I was enlightened by the exchange with Mvaldes over the past few days. I learned a new way to use it for analysis and troubleshooting, and just looking at his curve suggested what the problem might be.

WAY cool bringing that from the other side of the world, yup....

Your clinic idea is GREAT! Let's do that. Mr. Widget's gonna help me get started. We should all share using CLIO here....

[Hamilton]

It's apparent in this thread and others here that a simple RTA can carry the endeavor a very long way, indeed, and it certainly expedites the process.

If I've accomplished nothing else here, it has been to make the utility of an RTA familiar on the forum.

I've said it before, and it's worth repeating: I could not do this without one. No way.

If someone were to tell me two months ago that I would own an RTA I would have shook my head and scoffed, but now I do...because of threads like this one.

Yep, even we beginners, who don't post much or know much, have to be shown where to start... somewhere.

Carry on, Zilch.

[yggdrasil]

In order to maintain house peace I have to try to keep costs for audio equipment down, test equipment included.

After this thread about measuring back in september i downloaded speaker workshop. http://audioheritage.org/vbulletin/s...eaker+workshop

After some work I have started to get some results from it. For now I get impedance plots, which is what I am looking for right now.

I also bought Winairr and a Behringer measurement mic earlier this year. With Ian's help I was finally able to make good repeatable measurements.

I just ordered Joseph D'Appolito's book - Testing loudspeakers.

In my experience it is a long way, even with the equipment in house.

[Earl K]

,,,,,so far, I'd have made naught... you are one who likes bargains......... Earl, you of all people shouldn't be without it!

- Yeh, you're right about that . and that's why I'll eventually buy it . But that also dictates a migration over to the PC world which for me is the real problem ( complicating that migration is the fact that I also need a new main computer )


- I inserted this aside within this thread because IMO, I feel some of the guys have started hammering on Zilch a little too hard for his lacking of CLIO . I want to counter that. I feel he's done a lot of relevant explorations with a minimal tool set. This was done at his own expense in time & money / neither of which is trivial . Sharing all this with us is a great bonus . There are a lot of people who can relate to that. To attempt to trivialize it just because of a lack a more sophisticated software is disengenious to say the least.

- ( Also , I suspected the reaction to my posting was good for at least another 10 replies / gotta get this thread up to 1000 somehow, ya know, so Zilch can spend next year breaking it apart.

- Anyways, I really appreciate getting those insights into the use of impedance equalizers within networks ( and that was done under Zilches' watch ) .

[4313B]

I inserted this aside within this thread because IMO, I feel some of the guys have started hammering on Zilch a little too hard for his lacking of CLIO . I want to counter that. I feel he's done a lot of relevant explorations with a minimal tool set.

There is nothing to counter. Zilch has aquired a CLIO system and should be up to speed with it soon enough (Discussions about getting Zilch setup with CLIO were actually initiated behind the scenes quite some time ago). I suspect he will find it quite handy. He has also stated that he has aquired the recommended D'Appolito reference which others here are familiar with. What he has done so far is quite interesting and entertaining. He has shown what can be done with an RTA and how useful it can be. We won't get into how he has been using that RTA, he's learning. He'll get better.

This was done at his own expense in time & money / neither of which is trivial . Sharing all this with us is a great bonus . There are a lot of people who can relate to that. To attempt to trivialize it just because of a lack a more sophisticated software is disengenious to say the least.

Who is attempting to trivialize it? When it was first realized exactly how much time and energy he seemed willing to put into this there were quite a few discussions as to what to do about that. I believe one suggestion was for the forum to do a raffle in order to hook him up with more equipment to further his cause.

Done Dirt Cheap




Hey isn't that a song??

Rob

Yes. I think you might be starting to get where I'm coming from Rob. It's all just one big long Roadrunner cartoon.

Maybe not design, but there is picture back in old Stereo Review of a couple of insiders listening with an RTA by the side- just like Zilch. Listening to L100T models.
David F

How old?
Early 80's... yeah I was using a Urei Model 200 plotter back then.

- Yeh ,I too prefer the most economical approach
- Maybe if I was trying to get people to purchase speakers from me , it would be a different story .

Yeah, you Walmart shoppers kill me. You even want your JBL parts from Walmart. Or was that Radian parts? Hopefully JBL will see the light and finally discontinue support for all their legacy systems and components. I do believe Harman is working on doing just that.

[spkrman57]

I have WT2 and thought I was doing good. Can't afford CLIO or the others yet, but who knows, if I stop buying drivers and systems I might be able to afford that stuff down the road.

Ron

[4313B]

I have WT2 and thought I was doing good.

You are doing good. WT2 is great for getting your boxes dialed in a bit better than with pencil, paper, and a math formula. It's also quite a bit easier than doing paramters the old fashioned way - pencil, paper, a VTVM, a series resistor and a source generator.

You've probably learned now that TS parameters vary quite a bit and are more of a general tool than an exact science but they are a lot nicer than cutting down a whole slew of trees, building a whole bunch of different sized boxes and then trying various tunings to get a driver to sound like you want it to.

Can't afford CLIO or the others yet, but who knows, if I stop buying drivers and systems I might be able to afford that stuff down the road.

Whatever is most important to you. Maybe you just need to analyze what it is you wish to do. Do you really need a CLIO rig to meet your goals or will an RTA or something else suffice.

[Ian Mackenzie]

Thank you, Rob.

I must say I was enlightened by the exchange with Mvaldes over the past few days. I learned a new way to use it for analysis and troubleshooting, and just looking at his curve suggested what the problem might be.

WAY cool bringing that from the other side of the world, yup....

Your clinic idea is GREAT! Let's do that. Mr. Widget's gonna help me get started. We should all share using CLIO here....

Zilch,

Has it arrived yet?..I hope I have given the right opportunity!

Playing around with speakers is like walking around an elephant.

Its a big subject and it takes a while to see the full picture.

Used wisely, Clio as a tool will give you a better appreciation of the big picture.

In reference to more recent posts an audio tool will always serve you best when used for the intended application. Words to that effect are in the fine print on many JBL professional brochures.

[Zilch]

A pair of LE85's get new ($500 with shipping) D8R2421 diaphragms. Alignment pins on the driver make installation simple and Zilchproof.

Here on same H3100, N3100, B380, as above. Delicious HF extension. Compare to 2426H (below).

Impedance sweep of driver and horn, bottom.

[Robh3606]

Pssst

That's not extension it's a peak in the response that tops out at 8k. The roll off is still there. Take a look at this.

http://www.lansingheritage.org/image...4331/page2.jpg

http://www.lansingheritage.org/image...4333/page3.jpg

Look similar???

Rob

[Zilch]

Look similar???

Yup, but I'm talkin' about 12 to 20 kHz here, where 4331(A) dies.

Can't say I much like the peak. If it stays there after breakin, I'll notch it flat. It seems symmetrical, and thus easily "handled." I'd very much like to use this driver, diaphragm, horn, crossover combination. Not sure which LF yet, tho. LE14H-3 may be the better choice, but the B380 "Lowboy" is a kinda cool setup.

I was expecting the HF extension might be damped out with the diamond surround aluminum diaphragm. We already saw that the original tangential surround LE85's had a little bit more (and also sounded better) than the titanium 2426's. It's still there with these....

What's delicious is the way they sound, of course....

[Robh3606]

"I was expecting the HF extension might be damped out with the diamond surround aluminum diaphragm."

The RGA shown with the 4331 is the original aluminum diaphram. The extension you see in your display is from the diamond surround. That surround type extended the UHF response beyond what the original 2420 could do. Same with the 2440 vs. 2441.

http://audioheritage.csdco.com/vbull...ead.php?t=4410

Check out figure 4 2440/2441/Tad comparison

Also B Secondary Resonances on the same page.

Rob

[Zilch]

Thanks, Rob.

It's all GOOD then.

We'll let our new pal CLIO handle the peak....

[Zilch]

2235H's back from reconing by Audivex, here mounted in 5 cuft. JBL 4507 boxes. Closing off two of the four ports as shown retunes them to 27.5 Hz (black). For punchier but less extended bass, just one port closed tunes the system to 33 Hz (orchid). Curves cross at 33.76 Hz, -4.15 dB.

2352 90° x 50° horns with flange modified to accept 2435HPL 3" beryllium diaphragm drivers get a slight downward tilt. They should be moved forward for optimum time alignment, but I'm not yet ready to drill mounting holes in the cabinets.

Crossovers are developmental modification of AM6212, 1 kHz.

What are the woofer frames? Only Zilch's reconer knows for sure.

May be some 4430's for sale here soon....