New Project: Recommendation for bass driver.

[Sootshe]

Hi all,

Putting together a 3 way & have the mid & top drivers & crossovers. I was going to use the GPA 416-8B, but lately have been looking at the Acoustic Elegance TD15M. I read a report that says the AE has a problem with cone excursion on the outward stroke, which severely limits the cone travel, causing distortion.....see this link http://www.data-bass.com/data?id=52&page=driver, so that has put a doubt in my mind.

What would you recommend for a 15" JBL bass driver to give solid performance down into the low 30's?
The system will consist of the following:
15" bass driver in ported cab up to 250L, crossed at 500Hz to -
A55G Compresson mid mated to Altec 511B, crossed at 6000Hz to - sensitivity 106db
JBL 2404 tweeter
Crossover is from Werner Jagusch with autoformers & PIO caps.

As you can see, I believe I need a fairly high sensitivity woofer, say 97db minimum, to mate with the other components. Looked at the 2226 & would appreciate your opinions & other options.

Thanks

[Horn Fanatic]

Hi all,

Putting together a 3 way & have the mid & top drivers & crossovers. I was going to use the GPA 416-8B, but lately have been looking at the Acoustic Elegance TD15M. I read a report that says the AE has a problem with cone excursion on the outward stroke, which severely limits the cone travel, causing distortion.....see this link http://www.data-bass.com/data?id=52&page=driver, so that has put a doubt in my mind.

What would you recommend for a 15" JBL bass driver to give solid performance down into the low 30's?
The system will consist of the following:
15" bass driver in ported cab up to 250L, crossed at 500Hz to -
A55G Compresson mid mated to Altec 511B, crossed at 6000Hz to - sensitivity 106db
JBL 2404 tweeter
Crossover is from Werner Jagusch with autoformers & PIO caps.

As you can see, I believe I need a fairly high sensitivity woofer, say 97db minimum, to mate with the other components. Looked at the 2226 & would appreciate your opinions & other options.

Thanks

Greetings -

IMHO, you can't go wrong with the ALTEC. With a free air resonance of 24 Hz, in a 250 liter enclosure you shouldn't have much trouble reproducing 30 Hz. Personally, I wouldn't use a 2226 for anything but sound reinforcement.

Just sayin'...

H.F.

[Sootshe]

Greetings -

IMHO, you can't go wrong with the ALTEC. With a free air resonance of 24 Hz, in a 250 liter enclosure you shouldn't have much trouble reproducing 30 Hz. Personally, I wouldn't use a 2226 for anything but sound reinforcement.

Just sayin'...

H.F.

Yeah, that Altec is a great driver, but then I looked at the AE & thought that would be a cleaner more up to date sound.......ah....decisions, decisions.
Thanks for your thoughts on the 2226.....I don't really want to go down the PA type sound road, would much rather prefer a more detailed, clean, & smoother bass.

[Lee in Montreal]

And what about the venerable 2235 in your specified 8.8cft ?
If so, I'd even consider a 2245 in that same 8,8cft... ;-)

[Lee in Montreal]

... I wouldn't use a 2226 for anything but sound reinforcement.

Just sayin'...

H.F.

Well, it can sound pretty good and hifi, but requires a lot of processing. Major boost is required from 30Hz up to 70Hz. And I mean major... Better have a digital crossover... ;-)

[Sootshe]

And what about the venerable 2235 in your specified 8.8cft ?
If so, I'd even consider a 2245 in that same 8,8cft... ;-)

Wouldn't that 93db sensitivity be a little on the low side?

[ivica]

Wouldn't that 93db sensitivity be a little on the low side?


Hi,
May be two 2235, or 2235 + 2234...reaching about 99 dB (93 + 6 due to the mutual coupling)

regards
ivica

[Mr. Widget]

As you can see, I believe I need a fairly high sensitivity woofer, say 97db minimum, to mate with the other components. Looked at the 2226 & would appreciate your opinions & other options. I'm not a fan of the 2226H in a domestic setting though others seem to be happy with it. If you have the room, a pair of 2234Hs might be a great option.



May be two 2235, or 2235 + 2234...reaching about 99 dB (93 + 6 due to the mutual coupling)
Actually the pair of 2235s in a 4355 or the pair of 2234H in the 4435 are both rated at 96db.


Widget

[RMC]

Ivica and Mr. widget are both right but failed to explain their answer...

Mutual coupling of 2 identical drivers results in + 3 db due to the coupling itself (increased sensitivity of two sources close by), and MAY also result in another + 3 db due to increased (doubled) power capability of the two drivers compared to a single one. Naturally, the second 3 db may show-up if, an only if, the drivers are driven hard enough to get there. If not, then you get only + 3 db on sensitivity as Mr. Widget has shown. Regards,

Richard

[Sootshe]

I'm not a fan of the 2226H in a domestic setting though others seem to be happy with it. If you have the room, a pair of 2234Hs might be a great option.


Actually the pair of 2235s in a 4355 or the pair of 2234H in the 4435 are both rated at 96db.


Widget

Agreed, a pair of these per side would be quite good. Pretty hard to find a good pair, let alone a couple. I assume if I go this way that I would use the enclosure guide as per attached......a 10ft3 enclosure divided into 2 sections & tuned to 30Hz.
Do you know if genuine recone kits are still available for these , if so, I don't have to be too fussy about the condition of the ones I purchase.
Almost impossible to get these in Oz, so would need to probably come from the States, making freight a fairly expensive exercise.

I think I can get 21db attenuation with the autoformers in my crossovers, so maybe I don't need a pair per side & can get away with that 93db efficiency just using 1 driver per side.......Link to autoformer specs - https://www.ebay.com.au/itm/Autotransformer-passend-fur-Altec-and-other-Horn-Projekte/222726674049?hash=item33db8b5681:m:m7uCI7P__iu42LD S-PiHkDQ

Cheers,
John

[ivica]

...
Actually the pair of 2235s in a 4355 or the pair of 2234H in the 4435 are both rated at 96db.

Widget

Hi Widget,

You are right if we are talking about the efficiency, as two 2234/5 are working in parallel, so their "net" impedance in such configuration is 4 Ohms, but if it is applied the voltage from the amp of about 2.83Veff then the sound effect would be 99dB/1m (yes from the amp it would be consumed 2W of electric power), but I do not expect that the amp power here would be the limitation.
I do not want to mention here that in stereo configuration, lower frequency would be influenced by speaker mutual coupling too (especially if the room would be
of not so large size) plus teh room LF "gain", but all of that would be out of the topics here....

Regards
Ivica

[hlaari]

what about E145?
sensitivity 98db
a great bass driver with light cone that make him very fast and good for midrange also

[Mr. Widget]

I assume if I go this way that I would use the enclosure guide as per attached......a 10ft3 enclosure divided into 2 sections & tuned to 30Hz.
Do you know if genuine recone kits are still available for these , if so, I don't have to be too fussy about the condition of the ones I purchase.Genuine C8R2235 kits are still available. I would study the JBL 4435 design. This speaker has excellent bass. The pair of 2234Hs (2235H without mass ring) in parallel with one as the a helper woofer is an excellent solution.


Widget

[Ian Mackenzie]

Hi all,

Putting together a 3 way & have the mid & top drivers & crossovers. I was going to use the GPA 416-8B, but lately have been looking at the Acoustic Elegance TD15M. I read a report that says the AE has a problem with cone excursion on the outward stroke, which severely limits the cone travel, causing distortion.....see this link http://www.data-bass.com/data?id=52&page=driver, so that has put a doubt in my mind.

What would you recommend for a 15" JBL bass driver to give solid performance down into the low 30's?
The system will consist of the following:
15" bass driver in ported cab up to 250L, crossed at 500Hz to -
A55G Compresson mid mated to Altec 511B, crossed at 6000Hz to - sensitivity 106db
JBL 2404 tweeter
Crossover is from Werner Jagusch with autoformers & PIO caps.

As you can see, I believe I need a fairly high sensitivity woofer, say 97db minimum, to mate with the other components. Looked at the 2226 & would appreciate your opinions & other options.

Thanks

Due to the physics involved a single 15 inch wooder of that rated sensitivity will not give useable extension with out active equaliser applying 6 dB of boost and a port tuned to the low 30’s.

Have a look at DB keele’s Website extended box tuning

The other issue is Xmax

A 416 has relatively small Xmax to deliver usable authority in the low 30’s

The AE15m is a similar category of woofer

In 7 ft3 it will do the mid to high 30’s but not full power in the low 30’s

It just won’t happen

I have a pair and they are excellent

Most simulators of TL bass response modelling only give you a small signal prediction at 1 watt

So that means looking at dual 15 inch woofers or an extended bass woofer of lower sensitivity

The jbl 2234 is a good option as used in the 4435

It offers full power to the mid 20’s

But jbl will not sell genuine recone kits to consumers

It needs to be done by a jbl service centre like Jands in Sydney

Just call them to get further advice.

The other way to go is a B&C woofer as used in The Earl Geddes Summa and use several subs at below 80 hertz

The box is relatively small and you get you cake and eat it too

The other old chestnut is the Jbl 2245 18 inch woofer

That will reliably give you extended low bass but is only suitable to 250-300 hz.

[Ed Zeppeli]

You may consider the 2216ND-1

[Sootshe]

Genuine C8R2235 kits are still available. I would study the JBL 4435 design. This speaker has excellent bass. The pair of 2234Hs (2235H without mass ring) in parallel with one as the a helper woofer is an excellent solution.


Widget

Looked at some data on the 4435 & it seems very impressive.
When you say - "The pair of 2234Hs (2235H without mass ring) in parallel with one as the a helper woofer", do you mean using a similar crossover to that employed in the 4435?

I see that this crosses one over below 100Hz & then the other runs from above 100Hz. This set up would probably be beyond my capabilities to construct a passive crossover that would do this.

What if I ran 2 x 2234's in parrallel & ran them both full range up to the crossover point of 500Hz? The simplicity of this may outweigh the complexity of the additional components used by the 100Hz passive crossover? Just thinking out loud.

On the other hand, A single 2234 is probably all I need in terms of output & this would still be nearly 95db sensitivity, only about 2db down from the GPA 416 option, but gives me greater bass extension & a much smaller cabinet.

If I go with the 2234, they are going to be impossible to source here in Australia, so what's the best place to look for them in the States. I have a search saved in EBay & I know you have Craiglist & Canuck Audio Mart.....any other suggestions for sourcing these.

Many thanks,
John

[Sootshe]

Due to the physics involved a single 15 inch wooder of that rated sensitivity will not give useable extension with out active equaliser applying 6 dB of boost and a port tuned to the low 30’s.

Have a look at DB keele’s Website extended box tuning

The other issue is Xmax

A 416 has relatively small Xmax to deliver usable authority in the low 30’s

The AE15m is a similar category of woofer

In 7 ft3 it will do the mid to high 30’s but not full power in the low 30’s

It just won’t happen

I have a pair and they are excellent

Most simulators of TL bass response modelling only give you a small signal prediction at 1 watt

So that means looking at dual 15 inch woofers or an extended bass woofer of lower sensitivity

The jbl 2234 is a good option as used in the 4435

It offers full power to the mid 20’s

But jbl will not sell genuine recone kits to consumers

It needs to be done by a jbl service centre like Jands in Sydney

Just call them to get further advice.

The other way to go is a B&C woofer as used in The Earl Geddes Summa and use several subs at below 80 hertz

The box is relatively small and you get you cake and eat it too

The other old chestnut is the Jbl 2245 18 inch woofer

That will reliably give you extended low bass but is only suitable to 250-300 hz.

Appreciate your input on the AE's & the response is pretty much as I thought. I modelled this in WINISD & came up with a 250L box tuned to 37Hz, which gave me -3db at 37Hz.

That 2234 is a serious performer & one of those is probably all I need.......spoke with the guys at Jands & they have recone kits in stock, so all good there, just need to find some drivers somewhere.

[grumpy]

While looking for a core, keep in mind that a 2225, 2234, 2235 are functionally identical once the cone kit is removed (all could be made into a 2234)

[Sootshe]

While looking for a core, keep in mind that a 2225, 2234, 2235 are functionally identical once the cone kit is removed (all could be made into a 2234)

That's great info, I didn't know that, what would I do without you guys. Thanks.

[Ian Mackenzie]

Try eBay, Smithyscor Cannon Sound in Sydney for baskets

[ivica]

While looking for a core, keep in mind that a 2225, 2234, 2235 are functionally identical once the cone kit is removed (all could be made into a 2234)

Hi
even E130/140 basket can be used, but would produce several dB pronounced mid-bass, that can be reduced by EQ...., but 2225/34/35 are right solution.

regards
ivica

[Sootshe]

Try eBay, Smithyscor Cannon Sound in Sydney for baskets

So. I've picked up one driver from CC Light & Sound in Melbourne & another from an EBay seller in the States.
Both drivers are 2225H & appear to be in good condition. Will order the 2234 recone kits from Jands in Sydney tomorrow, now just need to find a reputable recone specialist.

Is the 5ft3 cabinet tuned to 30Hz the best way to go? That cab seems awfully small, yet it is JBL's recommended enclosure for a single 2234H.

[ivica]

So. I've picked up one driver from CC Light & Sound in Melbourne & another from an EBay seller in the States.
Both drivers are 2225H & appear to be in good condition. Will order the 2234 recone kits from Jands in Sydney tomorrow, now just need to find a reputable recone specialist.

Is the 5ft3 cabinet tuned to 30Hz the best way to go? That cab seems awfully small, yet it is JBL's recommended enclosure for a single 2234H.

Hi Sootshe,

Why to order recone-kits if the drivers are in good condition and have JBL original cone and VC.
I would suggest You firstly to measure their T/S parameters, and after that to decide what to do. Anyhow after a years of use driver foams would have to be replaced.
regards
ivica

[Sootshe]

Hi Sootshe,

Why to order recone-kits if the drivers are in good condition and have JBL original cone and VC.
I would suggest You firstly to measure their T/S parameters, and after that to decide what to do. Anyhow after a years of use driver foams would have to be replaced.
regards
ivica

Ivica,
The plan is to convert these to 2234, which from the specs of both the 2225 & 2234 drivers will give me a much lower frequency response than the the 2225.
Thanks, John

[ivica]

Ivica,
The plan is to convert these to 2234, which from the specs of both the 2225 & 2234 drivers will give me a much lower frequency response than the the 2225.
Thanks, John

Hi John,

Looking at the F/R:
http://www.jblpro.com/pub/obsolete/2225hj.pdf

I wonder if so large amount of $$$ (say about 500U$D ++) would be worthy for several dB under 40Hz, that can be EQ, may be.

regards
ivica

[Dr.db]

I believe several members have used the 2235/2234 drivers in a 6 ft3 enclosure, allthough JBL never sold them in anything bigger than 5 ft3.

The frequency response of a 7 ft3 enclosure looks even better, but I would worry about to much cone-excursion because of a loss of damping.

[Dr.db]

Hi John,

Looking at the F/R:
http://www.jblpro.com/pub/obsolete/2225hj.pdf

I wonder if so large amount of $$$ (say about 500U$D ++) would be worthy for several dB under 40Hz, that can be EQ, may be.

regards
ivica

Maybe a good point.

A 2235 would definetly sound a lot different to the 2225, but maybe a 2234 is very similar to the 2225 and not much of a change!?

[Sootshe]

Maybe a good point.

A 2235 would definetly sound a lot different to the 2225, but maybe a 2234 is very similar to the 2225 and not much of a change!?

Here's the TS specs for both of them. 20Hz fS versus 40hZ fS & so on........a fairly substantial difference I would have thought.

[Sootshe]

Hi John,

Looking at the F/R:
http://www.jblpro.com/pub/obsolete/2225hj.pdf

I wonder if so large amount of $$$ (say about 500U$D ++) would be worthy for several dB under 40Hz, that can be EQ, may be.

regards
ivica

Hi Ivica,
Thanks for the info, but I don't want to use EQ, just want the driver to perform at that range.

[grumpy]

IMHO, a 2225 does not sound like a 2234 or 2235, but the latter two are more similar than one might expect when put in the same size/tuned box
(having tried the 2234/5 comparison in a 4430 system... ~1kHz crossover range). There are proper uses for a 2225 where it will do quite nicely
and tearing up good drivers seems a (minor) shame, but at least if they work you know the magnets aren't shifted or have gunk in the gap.

[Sootshe]

IMHO, a 2225 does not sound like a 2234 or 2235, but the latter two are more similar than one might expect when put in the same size/tuned box
(having tried the 2234/5 comparison in a 4430 system... ~1kHz crossover range). There are proper uses for a 2225 where it will do quite nicely
and tearing up good drivers seems a (minor) shame, but at least if they work you know the magnets aren't shifted or have gunk in the gap.

Yes, If I'm going to do this, I want to do it right. This will be a long term keeper & this way I know that everything is correct.
Have ordered the recone kits & have a contact of Brisbane Sound to do the reconing. Will keep all up to date on progress.

[jlac4]

Yes, If I'm going to do this, I want to do it right. This will be a long term keeper & this way I know that everything is correct.
Have ordered the recone kits & have a contact of Brisbane Sound to do the reconing. Will keep all up to date on progress.
Hello Sootche
I'm planing to buy a recone kit for 2235 .Where do you intend to buy a good recone kit close to the original C8R 2235 .There 's a lot of shop in Usa and I don't know where to order .
Best regards
Alain

[Dr.db]

As you are located in europe, contact the member "guido" he is a dealer for JBL parts in germany and has some customers in france...

[toddalin]

2241H! :D

More volume, better articulation and detail than a 2235/2245, and can take what you throw at it.

Doesn't require a huge cabinet like a 2245.

Doesn't go as low as a "foam job," but a bit of eq can take care of that. Depending on the cabinet tuning, does have a very nice "bass bump."

Not highly sought after and can be had very reasonably (=<$$$). And, never needs a refoam!

Run WinISD and compare this to all other JBL woofers and you will be suprised of its capabilities. Blows away everything else, except the foam jobs, for deep bass.

[Ian Mackenzie]

For clarity the 2234 was used in pairs per the 4435 with box frequency of 26 hertz

http://www.jblpro.com/pub/obsolete/443035.pdf

The sensitivity of a single woofer is 96 db

The second woofer has a low pass filter above 100-150 hertz at 6 dB per octave

The tuning in the 4435 is an over damped alignment where both drivers “add”and level the response to 30 hertz

[Sootshe]

2241H! :D

More volume, better articulation and detail than a 2235/2245, and can take what you throw at it.

Doesn't require a huge cabinet like a 2245.

Doesn't go as low as a "foam job," but a bit of eq can take care of that. Depending on the cabinet tuning, does have a very nice "bass bump."

Not highly sought after and can be had very reasonably (=<$$$). And, never needs a refoam!

Run WinISD and compare this to all other JBL woofers and you will be suprised of its capabilities. Blows away everything else, except the foam jobs, for deep bass.
Thanks for the tip, but I don't want to go 18" for the bottom end - need to get all the way up to 500Hz for the first crossover point.

[Sootshe]

Hello Sootche
I'm planing to buy a recone kit for 2235 .Where do you intend to buy a good recone kit close to the original C8R 2235 .There 's a lot of shop in Usa and I don't know where to order .
Best regards
Alain

I'm located in Australia, so can't really help you with kits from USA. Take Dr db's advice re German distributor.

[Sootshe]

For clarity the 2234 was used in pairs per the 4435 with box frequency of 26 hertz

http://www.jblpro.com/pub/obsolete/443035.pdf

The sensitivity of a single woofer is 96 db

The second woofer has a low pass filter above 100-150 hertz at 6 dB per octave

The tuning in the 4435 is an over damped alignment where both drivers “add”and level the response to 30 hertz

Thanks Ian,
So just a simple low pass filter on one of the woofers.....sounds good. Now you've piqued my interest in the 2 woofer set up, although the cost will hold me back just at the moment. It's costing a small fortune to get the drivers, plus then the recone kits & then have someone recone them.......let's see how I like the sound of the single woofer set up.

[toddalin]

Thanks for the tip, but I don't want to go 18" for the bottom end - need to get all the way up to 500Hz for the first crossover point.


2241H goes higher than a 2235H and easily gets to 500 Hz. (Actually rated from 30-3kHz whereas 2235 is rated to 20-2kHz.) Vocals are more intelligible and articulated than a 2235. Also reverb and decay are improved as is the stereo image. I don't know how much dispersion (if any) you would loose over a 2235 crossed over at 500 Hz though, if that is an issue. I always sit in the sweet spot.

[Sootshe]

2241H goes higher than a 2235H and easily gets to 500 Hz. (Actually rated from 30-3kHz whereas 2235 is rated to 20-2kHz.) Vocals are more intelligible and articulated than a 2235. Also reverb and decay are improved as is the stereo image. I don't know how much dispersion (if any) you would loose over a 2235 crossed over at 500 Hz though, if that is an issue. I always sit in the sweet spot.

Good to know, thanks.