Drivers for DIY Heartsfield

[mbeards]

Hi everyone,

I am new to this forum. I joined after reading some great information posted by others and learned alot about the JBL product line.

I am planning building my own Heartsfield speakers and have a few questions on drivers.
Currently my planned driver lineup is: D130, 2441 (or 2440 w/ w2441 diaphragm), and 075 tweeter. Crossovers: 3115 and N7000

My first question: Will the D130 be a good fit to replace the 150-4C or is there a better option for the bass driver? I have done a bit of research and have seen it used before in Heartsfields.

Second: Is there a less expensive equivalent to the N7000 crossover? I did some looking around and couldn't find the crossover frequency of the N7000. I assume it is 7kHz.

Third: Are there any cheaper and more available options for the horn and lens used in the Heartsfield? Should I use a different horn and lens than the original since I am not using the 375? (any have a pair to part with?)

Fourth: The 3115 Crossover states to use an 8ohm woofer load and a 16 ohm high frequency load. Can I use a 16ohm woofer? I saw on another JBL data sheet or advert that you can use either an 8 or a 16ohm. Also what should I connect for my amplifier impedance if the crossover is running both an 8 and 16 ohm load?

This is going to be one massive project but I am ready for the challenge!

Thanks for any help
Matt

[hjames]

Not trying to be a spelling nazi - just a friendly heads up.

I believe they are called Hartsfield speakers - so if you google for info,
it would be helpful to get the spelling right.

Again, said in all friendliness!

here is a local link to help!

http://www.audioheritage.org/html/profiles/jbl/hartsfield.htm

[gasfan]

Not trying to be a spelling nazi - just a friendly heads up.

I believe they are called Hartsfield speakers - so if you google for info,
it would be helpful to get the spelling right.

Again, said in all friendliness!

here is a local link to help!

http://www.audioheritage.org/html/profiles/jbl/hartsfield.htm

If my hart was in it, I'd call it a heartsfield too! They are the cutest little things, aren't they?

[NickH]

The d130 has a low q so that mean the suspensions is very dampened. It would work in the Hartsfield I bet. Shoot, it would probably work in anything as horns go. It's a very different driver then the 150. Its curved cone is make to break up so it provides the higher frequencies. My first choice besides the 150 would be a 130a. Back in the days when the Hartsfield was first made the d130, 130, and 150-4c all used the same frame. The 150 had a ring on the mounting flange. But the magnet and frame were identical. Keep in mind this changed with the creation of jbl pro. But as for the other 2, d130 and 130. They were basically the same driver, almost. Same cone but different voice coil and dust cap. The d meant it used an aluminum dust cap and a aluminum voice coil. This made a driver with great mid range and higher mid bass. But no low bass as the d130 had very little excursion.

Sorry for the little driver history and genealogy lesson.

That being said, I'm no expert but I think the d130 will work. It will not give the same results though.

Hope thus helps a bit,
Nick

[mbeards]

Thanks for the help Nick,

I actually just discovered the 130A myself. Never knew it existed. I only knew about the D130 and D130F. The 130A sounds like the ticket based on what you and others have said. Sounds like it is capable of lower frequency response. Now I need to find a pair with original cones! I am willing to bet that most have been re-coned with a D130 kit or equivalent. I did some searching and cant find 130A re-cone kits anywhere.

Matt

[NickH]

[QUOTE=mbeards;350309]Thanks for the help Nick,

I actually just discovered the 130A myself. Never knew it existed. I only knew about the D130 and D130F. The 130A sounds like the ticket based on what you and others have said. Sounds like it is capable of lower frequency response. Now I need to find a pair with original cones! I am willing to bet that most have been re-coned with a D130 kit or equivalent. I did some searching and cant find 130A re-cone kits anywhere.

Matt[/QUOTE

I believe there's a pair on ebay right now. At least there was. Theoretically you could convert a d130 to it by adding 10 grams mass under the dust cap. But I've not tried it.

I'm going to try and make some in the near future. Just for clarification, when jbl pro came to be they change them completely. I think the later 130a and a 2220 were the same. Come yo think of it a jbl 2205a or 2220a would be other good options. Not completely sure the 2205, but I bet money the 2220 would work.

Nick

[mbeards]

I believe there's a pair on ebay right now. At least there was. Theoretically you could convert a d130 to it by adding 10 grams mass under the dust cap. But I've not tried it.

Nick


Just bought that pair! They were cheap and looks like they have been re-coned with the right 130A kits. The ad stated the cones were stamped 21057. I did some quick looking and I think that is the right cone. Any thoughts?

Matt

[Oldmics]

The E 145 would have been the next best speaker to use other than the 150.

Oldmics

[NickH]

The E 145 would have been the next best speaker to use other than the 150.

Oldmics

I wish the sensitivity was know for the 150-4c. Because I'd bet they were much higher sensitivity then the 145's. Not to mention the completely different voice coil and gap configuration. I know the 150-4c had a .28 inch deep gap. The 145's are both thicker then that and under hung. I don't know if the 150 was over hung or the same size as the gap depth. Plus there not as easy to find. I'd love to find 4. But that's not going to happen any time soon.

Plus it hard to even get aftermarket parts for them. And jbl left them behind in the 90 s didn't they?

Nick

[ratitifb]

59468

[ivica]

Hi everyone,

I am new to this forum. I joined after reading some great information posted by others and learned alot about the JBL product line.

I am planning building my own Heartsfield speakers and have a few questions on drivers.
Currently my planned driver lineup is: D130, 2441 (or 2440 w/ w2441 diaphragm), and 075 tweeter. Crossovers: 3115 and N7000

My first question: Will the D130 be a good fit to replace the 150-4C or is there a better option for the bass driver? I have done a bit of research and have seen it used before in Heartsfields.

Second: Is there a less expensive equivalent to the N7000 crossover? I did some looking around and couldn't find the crossover frequency of the N7000. I assume it is 7kHz.

Third: Are there any cheaper and more available options for the horn and lens used in the Heartsfield? Should I use a different horn and lens than the original since I am not using the 375? (any have a pair to part with?)

Fourth: The 3115 Crossover states to use an 8ohm woofer load and a 16 ohm high frequency load. Can I use a 16ohm woofer? I saw on another JBL data sheet or advert that you can use either an 8 or a 16ohm. Also what should I connect for my amplifier impedance if the crossover is running both an 8 and 16 ohm load?

This is going to be one massive project but I am ready for the challenge!

Thanks for any help
Matt

Hi ,
Nice to join us.
About mentioned Hartsfield box be aware about the : "...It was a natural fit that Bill Hartsfield would be called upon to develop JBL's version of a corner horn. He was hired on retainer as a consultant to JBL to develop a corner horn speaker....." not to mention how complicated the whole construction would be, but I wish You good luck..
see plans:

http://www.lansingheritage.org/html/jbl/plans/harts.htm


Regards
Ivica

[mbeards]

Thanks for the info. if the 130A's sound a bit lacking I will try the E145's

Also others may find this interesting: here are some Hartsfield plans I ordered based on CAD drawings of an original!

http://www.audio-kits.com/catalog/item/4071362/4158237.htm

[NickH]

Good luck finding some. There out there but nowhere near as common as the 130a.

plus you'll lose 4 db in sensitivity. But there supposedly a great driver. Oh and they fetch a bit more, obviously.

In retrospect I'm sorry I didn't think to mention them too. They didn't even cross my mind.

As with any true horn driver, they don't provide well down real low.

Nick

[mbeards]

No problem Nick,

I saw others on the web using D130's with good success (or so they say) so I would imagine that the 130A would be a step up from that.

The last hurtle, from a driver standpoint, is to find some horns and lenses that are not ridiculously expensive!

Any one want a nice guitar as a trade?? http://www.audioheritage.org/vbulletin/images/icons/icon10.png

[NickH]

You can't really compare a d130 and a 130a like that. The d130 is not a woofer actually. Its a semi full range driver. The 130a is a woofer though. Hence why I say you can't really compare them.

But between the 2 of them for you desired application, yes its the better of the 2. I like to think of it as a poor man's 150, lol. Not that it has many similarities to the 150. The one thing you have to watch out for is jbl changed the 130a many years ago. It went from an accordion surround driver to a foam half roll. There completely different animals altogether. The accordian surround driver is the horn driver. The reason I say poor man's 150 is in the old catalogs. All the big horn cabinets that the 150 is the top suggestion, the 130a is a much cheaper driver selection. But the similarities of the 130a and the 150 end there.

As the the six string, don't know if you can put it up in the none Lansing marketplace.

Craigslist?

As for the horns, good luck. Those serpentine horn lenses that were on the harts are insane.
but if you separate them from the bass horn it would make life a bit simpler.
Nick

[John W]

No problem Nick,

I saw others on the web using D130's with good success (or so they say) so I would imagine that the 130A would be a step up from that.

The last hurtle, from a driver standpoint, is to find some horns and lenses that are not ridiculously expensive!

Any one want a nice guitar as a trade?? http://www.audioheritage.org/vbulletin/images/icons/icon10.png

This add has been up for a long time on Craigslist in Seattle:
http://seattle.craigslist.org/see/msg/3934673946.html
I've contacted the seller in the past about his horns, but don't recall the price. It was too high at the time.
I do remember he is a bass player, and was looking for trades.
If you can work something out, I can help getting them shipped.

[mbeards]

This add has been up for a long time on Craigslist in Seattle:
http://seattle.craigslist.org/see/msg/3934673946.html
I've contacted the seller in the past about his horns, but don't recall the price. It was too high at the time.
I do remember he is a bass player, and was looking for trades.
If you can work something out, I can help getting them shipped.


Just contacted the seller. Hopefully he has two of those lens assemblies!

Thanks for the link! It is much appreciated

Matt

[Oldmics]

Those Craigslist lenses are probably McCaully devices.

Might want to get measurements to compare to a JBL product and see if they are plastic or made of metal.

Oldmics

[mbeards]

So Im making notes and adding small edits to my blueprints for the Hartsfields.
I know during the last years of production it was turned into a 3 way system.

Any suggestions on 075 tweeter placement?

I have seen them placed behind the grills on the top left or right corner of the speakers. This is based on one photo I found on google with the grills removed.
I was thinking of making a cutout in the grill to fit the barrel of the 075 tweeter through so it is visible once the grill is on.

Was this the standard position or is there a better spot to place it?
I have done a little reading where it is suggested that placing the tweeter off center improves diffraction properties.

Matt