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... ;-)

[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

[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... ;-)

[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

[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/Autotran...iu42LDS-PiHkDQ

Cheers,
John

[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

[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

[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.

[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

[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

[hlaari]

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