New Project: Recommendation for bass driver.

[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.


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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.