free air resonance is about 40hz so it is not toasted or burned.
i followed suggestions above.
i first eleminated the horn and used one of my bose 301 as the upper range tones.
brought up the inductor near 10mh with still 60uf cap. this cutted off almost all the vocal
added a 1mh inductor in series with a 20 ohm potentiometer, this brought up some mids, adjustable.
with a white noise and spectrum analyser i found out that there is a resonance still near 120hz and a dip at 60, and it goes up to 28-30 (cabinet tuned to that so no surprise)
it plays far better like this but is still far from what i was expecting. i can get low bass since all the rest is muffled down....yeah.
as for the horn...it needs to be seriously muffled down at 2-8k, which would require a lot of cross over work.
so all in all, this is a very bad project to start with
-bad woofer selection, 2225h is not very well favored for a vlf =*>i am talking /expecting 20-40hz operation
-too large enclodure for the poor old woofer
-horn is soo agressive....way too much.
soo i will toss this away i think. money not well spent.
i followed suggestions above.
i first eleminated the horn and used one of my bose 301 as the upper range tones.
brought up the inductor near 10mh with still 60uf cap. this cutted off almost all the vocal
added a 1mh inductor in series with a 20 ohm potentiometer, this brought up some mids, adjustable.
with a white noise and spectrum analyser i found out that there is a resonance still near 120hz and a dip at 60, and it goes up to 28-30 (cabinet tuned to that so no surprise)
it plays far better like this but is still far from what i was expecting. i can get low bass since all the rest is muffled down....yeah.
as for the horn...it needs to be seriously muffled down at 2-8k, which would require a lot of cross over work.
so all in all, this is a very bad project to start with
-bad woofer selection, 2225h is not very well favored for a vlf =*>i am talking /expecting 20-40hz operation
-too large enclodure for the poor old woofer
-horn is soo agressive....way too much.
soo i will toss this away i think. money not well spent.
I wouldn’t give up that easily.
Shorten the bass reflex, fill the cabinet with some sand or other heavy material to stiffen it and reduce volume, add more bracing to start with maybe less damping. The point is to increase boom 50-100hz and forget about the bottom octave. Try a smoother but higher xo on the horn with variable lpad. Many things to explore here. And ensure the drivers are properly broken in 100 hours of playtime minimum. You can also try sealed but I doubt it will help.
Shorten the bass reflex, fill the cabinet with some sand or other heavy material to stiffen it and reduce volume, add more bracing to start with maybe less damping. The point is to increase boom 50-100hz and forget about the bottom octave. Try a smoother but higher xo on the horn with variable lpad. Many things to explore here. And ensure the drivers are properly broken in 100 hours of playtime minimum. You can also try sealed but I doubt it will help.
Last edited:
i have lpad already. spectrum shows resonance (high output )( at 120hz and 2khz.
my room is large, 20x20 if not more...
20x20 feet or meter? If the later you will need more drivers and maybe three way 
Try some of the advices above tuning up to 50 Hz for more boom/powerful bass and forget about the lowest sub who really need that it’s not really possible with 2-way it’s all by compromising. I’m sure the horn can be solved with a small mod in xo, polarity or a band stop notch.
Making this work is great practice. Don’t start a new project, make this work first and then see.
Try some of the advices above tuning up to 50 Hz for more boom/powerful bass and forget about the lowest sub who really need that it’s not really possible with 2-way it’s all by compromising. I’m sure the horn can be solved with a small mod in xo, polarity or a band stop notch.
Making this work is great practice. Don’t start a new project, make this work first and then see.
20x20 feet or meter? If the later you will need more drivers and maybe three way
Try some of the advices above tuning up to 50 Hz for more boom/powerful bass and forget about the lowest sub who really need that it’s not really possible with 2-way it’s all by compromising. I’m sure the horn can be solved with a small mod in xo, polarity or a band stop notch.
Making this work is great practice. Don’t start a new project, make this work first and then see.
its in feet
thanks for your help and encouragements !
To summarize:
- decrease volume / fill with sand or similar quite a bit I would think
- shorten bass reflex, consider maybe also bigger diameter
- add more bracing to remove the 120Hz resonance
- think about position, place speaker closer to wall, same with listening position
- try a first order filter instead at low volumes only, but with higher xo point on HF to avoid 2kHz peak
- ensure proper driver break in 100 hours play.
- remove some damping, or add/change material
- use spikes?
- decrease volume / fill with sand or similar quite a bit I would think
- shorten bass reflex, consider maybe also bigger diameter
- add more bracing to remove the 120Hz resonance
- think about position, place speaker closer to wall, same with listening position
- try a first order filter instead at low volumes only, but with higher xo point on HF to avoid 2kHz peak
- ensure proper driver break in 100 hours play.
- remove some damping, or add/change material
- use spikes?
Last edited:
Try also get some inspiration from the PI 4 speaker design, crossover etc drivers is very similar to yours. I think your tuning and xo is the main issue.
Pi Speakers - four Pi loudspeaker performance data
Pi Speakers - four Pi loudspeaker performance data
very interesting, thanks very much for all thoses precious informations !
I cannot promise any improvement, I am in the same process myself with some of my builds and I’m an amateur, others may have better advice especially on the crossover. But it doesn’t hurt much to try the above, none of the suggestions have any cost but time and effort which is a learning process anyway. If it’s successful you will be much more motivated in the next project instead of starting blank again.
The 120 Hz could probably be an internal resonance of the box due to ist height. If that really is the case it could be reduced by damping.
And yes, I would also go higher with the tuning. Around 35 to 40 Hz is better with that driver and box size. A little reduction in size would not be bad either ("doate" the part below to the crossover as separate compartment).
Regards
Charles
And yes, I would also go higher with the tuning. Around 35 to 40 Hz is better with that driver and box size. A little reduction in size would not be bad either ("doate" the part below to the crossover as separate compartment).
Regards
Charles
Last edited:
i measured the box internal volume more acurately
it is 6.21 ft3 minus the speaker volume itself so it may fall more close to 6ft3 instead of 7.
port is 4x4....
box is has all of its walls with damping material.
the 120hz feels more like the speaker itself that resonate in it armature or basket....
my only fear is that at the far end i will find out that the 2225h is just not good for a vlf speaker....hence my question for another driver, while trying to keep this box "as is"...
it is 6.21 ft3 minus the speaker volume itself so it may fall more close to 6ft3 instead of 7.
port is 4x4....
box is has all of its walls with damping material.
the 120hz feels more like the speaker itself that resonate in it armature or basket....
my only fear is that at the far end i will find out that the 2225h is just not good for a vlf speaker....hence my question for another driver, while trying to keep this box "as is"...
Not sure what you mean by vlf, very low frequency? The driver is not a subwoofer to my understanding it’s a traditional bass/mid bass driver for high dynamics and punch but require a smaller cabinet vol and higher tuning to do so. And in any case you have designed it as a 2-way speaker and compromises must be done. Deep bass usually go for the benefit of efficiency or clear mids. This speaker project can be good I’m sure, the driver should be good for its intended use (see the PI article), but if your original idea was sub then it makes no sense to have a passive xo and a horn in there, it should be active 80hz LPF but then this driver may not be the one you look for unless you design a new horn sub cabinet. Maybe you can say some more of your needs. Is it a sub you want? Or a two way full range?
Last edited:
6cf is like 165 litres right? It must be way too much for this driver.
With the 2225h driver I think you have a couple of options:
- 2-way speaker / small cabinet, good punch/mids but no sub (50-1000Hz). Like 46710, I think this was your inspiration but you got greedy and wanted more out of it hence your current problems
- 3-way speaker / a little larger cabinet, deeper bass but you need separate mid (35-250Hz). 4628 style. Would require a complete remake in your case.
- Sub-Horn 4530 style, I guess high SPL in 60-80Hz, still no subs I would believe and you would still the xo issue with transition to HF.
I don't think you will be able to go complete full range with a 2-way system no matter the drivers you will always lose something. But do you really need anything below 45Hz? If not you have hopes fixing your current design.
In any case I still don't know if your driver is factory new or broken in, I believe these needs plenty of play time especially if its 30+ years old un-used.
My point is, I don't think a new driver will solve your problem.
Your objectives is too high expectations of a 2-way but if you can drop the bottom octave your in luck there are solutions for you to make a good speaker with small mods.
With the 2225h driver I think you have a couple of options:
- 2-way speaker / small cabinet, good punch/mids but no sub (50-1000Hz). Like 46710, I think this was your inspiration but you got greedy and wanted more out of it hence your current problems
- 3-way speaker / a little larger cabinet, deeper bass but you need separate mid (35-250Hz). 4628 style. Would require a complete remake in your case.
- Sub-Horn 4530 style, I guess high SPL in 60-80Hz, still no subs I would believe and you would still the xo issue with transition to HF.
I don't think you will be able to go complete full range with a 2-way system no matter the drivers you will always lose something. But do you really need anything below 45Hz? If not you have hopes fixing your current design.
In any case I still don't know if your driver is factory new or broken in, I believe these needs plenty of play time especially if its 30+ years old un-used.
My point is, I don't think a new driver will solve your problem.
Your objectives is too high expectations of a 2-way but if you can drop the bottom octave your in luck there are solutions for you to make a good speaker with small mods.
Attachments
Last edited:
you are right on all points, i went too greedy with the project, initial inspiration was the 4671, later 4530 but way too large for my room.
Do you have the specs of the 4628 ? internal volume, port,...i wouldlike to simulate that on winisd to see
otherwise i will try to shave some ft3 out of my existing cabinet to 5ft3 and see from there.
thanks very much
Do you have the specs of the 4628 ? internal volume, port,...i wouldlike to simulate that on winisd to see
otherwise i will try to shave some ft3 out of my existing cabinet to 5ft3 and see from there.
thanks very much
Last edited by a moderator:
I’m really not an experienced DIYer and especially not with vintage JBL or big 2-ways, the findings above was just some simple google searches on your driver. You can do the same and you will find tons of projects and advices but the common is that they don’t go very deep, they are more traditional bass drivers more than a sub, but still I understand they are great drivers in the right design
I know the feeling you have though. I’ve made a few designs where my hopes was too much, but my lack of simulation skills and proper planning resulted in a bad box design even with great drivers. Don’t blame the driver though. Good thing is that is fixable. You can do a lot with your current box to improve without starting over.
My only experience with JBL though is surreal. In my younger days I worked part time at a hifi shop (to get factory price and equipment discounts primary...) and we were so exited to get the Everest in house for a few months. It had no bass. Great sound and dynamics but so thin? You don’t expect that when you’re 20 years old and see a dual 15 inch speaker to 50k but I truly learned something back then.
I’ll leave the detailed xo advice to someone else, I don’t have that amount of theory skills. I’m sure you will get help here though.
I know the feeling you have though. I’ve made a few designs where my hopes was too much, but my lack of simulation skills and proper planning resulted in a bad box design even with great drivers. Don’t blame the driver though. Good thing is that is fixable. You can do a lot with your current box to improve without starting over.
My only experience with JBL though is surreal. In my younger days I worked part time at a hifi shop (to get factory price and equipment discounts primary...) and we were so exited to get the Everest in house for a few months. It had no bass. Great sound and dynamics but so thin? You don’t expect that when you’re 20 years old and see a dual 15 inch speaker to 50k but I truly learned something back then.
I’ll leave the detailed xo advice to someone else, I don’t have that amount of theory skills. I’m sure you will get help here though.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.