Hi there.
First off apologies for the lack of knowledge and thanks in advance for all the help!
Looking to replace the Beyma 18G400 drivers in these bass cabs and have got a couple of JBL 2242HPL off ebay (possibly prematurely) the specs look decent on paper but seems like the more I try to look into it the more it seems like they won't be as good in the sub bass end. I don't understand why though because as far as I can work out (from the limited readings on speaker perameters) they should be better. but Data-Bass has them down as more of a woofer than sub woofer and WinISD seems to agree as far as I can tell (could be doing something wrong though)
There is also the other matter of what modifications I might/will need to make to the cabs in order to get the most from the drivers. They are approx 150litres internal and the vent seems to be around 20litres (not sure that's the important measure for vents though) h9xw54xd40cm. Have been trying to find all of this out myself but its a bit overwhelming so thought I would ask on here.
Thanks again for any help given. and happy to do some more measuring or give some more details if I have missed something.
Why do you want to replace the drivers? Are they blown?
If it is more output you are after: for a given enclosure size and low frequency extension, the efficiency is more or less fixed. Better / newer woofer can have a higher power handling though.
150 L net and those port dimensions result in a tuning of 40 Hz.
If it is more output you are after: for a given enclosure size and low frequency extension, the efficiency is more or less fixed. Better / newer woofer can have a higher power handling though.
150 L net and those port dimensions result in a tuning of 40 Hz.
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Cool, thanks for the info. 40hz makes sense based on the old drivers.
One of the old drivers is blown. and they don't make them anymore, they do sell a re-cone kit but I would also quite like to 'upgrade' them a bit. ideally I would like more sub bass response and also some more power in general. is that possible with the jbl's? and what would I need to do to the cabs to bring the tuning down?
One of the old drivers is blown. and they don't make them anymore, they do sell a re-cone kit but I would also quite like to 'upgrade' them a bit. ideally I would like more sub bass response and also some more power in general. is that possible with the jbl's? and what would I need to do to the cabs to bring the tuning down?
mmm, yeah would have liked to get some pd1850's but budget doesn't allow at the moment.
have seen a few different specs for the jbl's. Data-Bass has the fs at 27hz while jbl states 35... someone had tested them for winisd and had them at fs30.. I am presuming if I use them it would be good to tune the ports/cabs to that frequency? if so how do I go about that?
have seen a few different specs for the jbl's. Data-Bass has the fs at 27hz while jbl states 35... someone had tested them for winisd and had them at fs30.. I am presuming if I use them it would be good to tune the ports/cabs to that frequency? if so how do I go about that?
Not necessarily.
You need to run some simulations (WinISD Pro or Hornresp) and find out what port tuning frequency would work best for your drivers in that size cabinet.
Chris
Thanks for the tips, they all look pretty good. Unfortunately I think I might be stuck with the jbl's for now.
Thanks Chris.
Yes I realise now that what I should have done is run a load of tests with the cab/tuning to see what would work best
oh well you live an learn (hopefully)Well it looks like tuning the cab to 38hz would preduce the flattest response.
with the cabs at 40 there is a bit of a peak around 50hz (+1db)
Is this worth worrying about. how difficult would it be to adjust the port to tune to 38hz? is it something that's best fixed with some eq'ing?
Changing the port tuning frequency is a matter of woodwork, and making sure the additional port length (bear in mind it'll cut into the cabinet volume, so it can end up an iterative calculation) is well sealed to the rest of the cabinet.
I wouldn't bother. 40Hz extension is enough for most music. If you get a big-name EDM artist through your venue, it might be worth hiring in something that'll hit 25Hz with authority.
Chris
I wouldn't bother. 40Hz extension is enough for most music. If you get a big-name EDM artist through your venue, it might be worth hiring in something that'll hit 25Hz with authority.
Chris
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