D130F Alway room for Improvement

[Zilch]

Assuming the baffle thickness is 0.75", your 9.9 cuft cabinets with heavy fill are tuned to 45.5 Hz (blue).

If the fill is more like "typical," instead, it's 48 Hz (orchid).

In either case, its not a bad alignment in comparison to the one suggested by BB6P for "extended bass" (red).

A bit "boomy," perhaps, but you've got useable bass down to 38.5 Hz.

0.18 Watts worth, before you run out of cone excursion, for 93 dB max acoustic power there.

[8" 116A closed-box Minis will do that quite nicely.... ]

[Zilch]

Zilch I will go back and give the posts relative to Air Suspension a more careful read.

Relevant for the 123A-3s, but not the D130s. BB6P recommended closed box for D130 is the black curve, above. Terrible, or rather, worse than what you've got.

When I originally built these my attitude about the extra midrange I put in and the 3 tweeters was...

ACK!!

[Harvey Gerst]

Here's a question on impedance. The D130F's are 4 ohm.

Are you sure they're 4 ohms? Most of the D130F's were 8 ohms.

Check with an ohm meter. A 4 ohm speaker will have about 3 ohms DC resistance.

[BMWCCA]

While we're picking Harvey's brain:

In a recent discussion on re-boxing my 030 system (D130/N2400/075 as if you didn't know), Zilch ran the BB6B program which indicates the 030 would actually produce better bass in the Baron C38 compared to the C37 (what mine are currently). I found that hard to believe but it would be interesting to know the opinion of someone who was there at the conception. The discussion came up when I was considering putting the 030 in an L200 box or, now that Heather will soon be picking up the empty L200s, perhaps putting the 030 in Heather's old 4320 boxes. I certainly realize that Zilch knows way more than do I about DIY (that wouldn't take much, unfortunately), but I assume you all played with the D130 to determine optimum reflex cabinet size and that there'd be no reason for the C37 if the C38 worked better. Any comment? I certainly do appreciate your counsel here. My JBLs have been in my family since I was five-years-old (and my Dad purchased the first in 1958, so you do the math!). Thanks for any help, advice, stories, and for just being here to shoot the sh*t with us.

[Zilch]

In a recent discussion on re-boxing my 030 system (D130/N2400/075 as if you didn't know), Zilch ran the BB6B program which indicates the 030 would actually produce better bass in the Baron C38 compared to the C37 (what mine are currently).

Well, no, what I SAID was:

So, what BB6P is telling ME tonight is if I want an improved (maximally flat) alignment for D130, it's put the 030 system in a smaller box more like Baron (or slightly smaller, even,) tune it properly, and run a sub with them.

The gist of the exercise being that it's largely pointless trying to get extended bass out of a D130; instead, align it to take maximum advantage of what it DOES do well, which isn't bass:

http://audioheritage.org/vbulletin/s...305#post153305

That's why I'm suggesting that GeneT consider repackaging his D130s in boxes 1/3 or less the size of his present systems, and mate subs with them. By contemporary standards, D130 is a midbass driver, not an extended-bass woofer. Even originally, it was not sold as a "low frequency transducer," rather, as an "extended range loudspeaker." In the MI versions, D140F was the bass driver....

[Thom]

Here is an Old Thurston Howell The III quote (Jim Bacus) from Gilgians Island "Anyone who says money can't buy happiness, doesn't know where to shop".

Hoenstly though I don't care if I end up with Ring Radiators or Ringless Radiators as long as I sit down at the end of the day turn on the stereo and put a smile on my face.

Zilch I will go back and give the posts relative to Air Suspension a more careful read.

Here's a question on impedence. The D130F's are 4 ohm. When I originally built these my attitude about the extra midrange I put in and the 3 tweeters was, they are crossed over and I don't really care about the impedence (of the mid and high), as long as it's 4 ohms or greater and the sound comes out balanced. I do have a wire wound pot connected to the tweeters for adjustment. My inclination these days, without really knowing the tweeters mentioned would be to put in 2 8 ohm units in parallel, run them at 4 ohms and put the pot in to balance them. I'd be a bit concerned about a single tweeter keeping up.

As far as subs go I'm close to picking up a HSU Research VTF3-MKII. I've read nothing but good things about HSU and for that matter SVS. Cool thing about HSU is that there is an "ask" function on the web and Dr Hsu himself replied back with server possible suggestions based on setup, room size and room configuration. The man must believe in his product to go to the trouble of personalized service. I emailed on a week end and got a reply back during the week end (Dr. Hsu - get a life!). Pretty impressive. Gene

If the single tweeter you are concerned about is the 075 have no fear. Just take a look at the efficiency compared to the cones. You'll still pad the 075.
The 075 gets a real bad rap here and I'm not into an argument right now but when the 077 I think it's called came out the benefit that was pushed was pattern not harshness. With the 075 there will definitely be a sweet spot. Wonder what happens if you hang a lens in front of it? I've never seen it so I'm guessing it's not too effective.

[GeneT]

If I though I would take a beating for cabinet size, I am ready to accept my punishment for ignorance and mis-information. I knew these were 4 ohms. They both came out of a single Sunn lead guitar cabinet mounted top and bottom, so both wired in series yield 8 ohms. Perfectly logical but, thought I, I'll crack open the cabinet and snap a picture and let my luminance shine (my meter died a few weeks back). Yes they are 4 ohms but they are 130F-2's. I have been calling them D130F's for years and I stand ready to assume the position. Gene

[GeneT]

So much for self-flatulation. Now that I've admitted fault what's the difference between a D130F and 130F-2 other than maybe 4 ohms. I can't find a reference to 130F-2 using the seach engine for this forum or google. I'm waiting for the folks from Antique Road Show to call and tell me I have a national treasure worth at least 6 figures.
--
Nooo.. the single tweeter I was worried about would not be the 075's. I love good toys but I'd find it hard to pony up $400-$500 for a couple of tweeters. Most of what I have, I've bought pretty right and that is sweet music in it's self. I do really appreciate all the info, it fires up the imagination. Thanks - Gene

[BMWCCA]

Well, no, what I SAID was:
The gist of the exercise being that it's largely pointless trying to get extended bass out of a D130; instead, align it to take maximum advantage of what it DOES do well, which isn't bass...

Got it. Though I like the sound they produce the way they are. Probably why I think everything else overdoes the bottom end, after fifty years of listening to these. Nobody ever complained and the JBL dealer insisted when I bought the L112s that I'd like them better than the 030s. It just never happened. Something about old dogs and new tricks, and me and my 030s are both old dogs.

Not that I don't enjoy my L112s, L150As, and 4412As. Different strokes....

[Zilch]

I don't know what 130F-2s are, but I do know that JBL was kinda fast and loose about what impedance they put on the foilcals back in the olden days, and the only way to know what they really are is to measure them.

DCR will give an indication, but not an absolute determination of the actual impedance.

It's not on the Transducer List....

[GeneT]

We'll I'm unique, but it's not the first time...I digress. If I had to guess they are probably D130F's designated 130F-2 because they were parried up in a Sunn Cabinet. To paraphrase a recent commercial... I totally don't know what they are but I like them. I wandered back to the computer from listening to a CD of Lilly Wilde a regional Jazz artist doing Stormy Weather. Thank the Good Lord for music, the people who do it and the companies with a passion for presenting it properly. In any case I'll bring home a meter and veirfy the DC resistance. - Gene

[Harvey Gerst]

After 50 years of use, I suspect that the Fs will drop a bit, so some of the T/S parameters might be wrong by now.

[GeneT]

Well after reading a bunch of post on other threads what has started out as a simple maybe I could shrink these a bit has cascaded into,
I need to re-access the tweeters and midrange I'm using, with a preference towards $450.00 075's, or I could use 2402's, but the're a bit beamy, midranges will be dependant on where I roll the frequency over at which will depend on whether I shrink the cabinets, or not and then I can build the custom crossovers because the stock ones look to be mainly for 8 ohms, making sure that I use the "poly" caps instead of the electrolytics with inductors the size of small power stations making sure they are seperated and turned 90 degress. Not that this is bad I suspect it will all make a subtantial difference but it's not where I thought I was headed. Did I miss any major points :|? - Gene

[Zilch]

Did I miss any major points :|? - Gene

Yes, what Zilch said:

The money you'll spend on POS 075/2402s will buy you a pair of JBL's TOTL Be-diaphragm compression drivers, 2435HPL, used. An additional $200 will get you a pair of new JBL PT waveguides to mount them on. Make small (2.4 cuft) mid/high boxes tuned properly to stack on subs.

http://www.jblpro.com/ae/pdf/PT_WaveGuide.pdf

Get radical: do something RATIONAL with your D130s....

[clmrt]

WinISD =

2.4

Tune to 60hz

2x 4.5" vents, 4" diameter

Sound right?