JBL E-145 enclosure

[Dr.db]

Hey,


I bought myself a pair of E-145`s.
My idea was to build some vented reflex-enclosure`s, but I´m not quiet shure about the internal box-volume. All I`ve found was the JBL 4628B which includes the E-145... It`s about 127 litres (4.5 cubic feet) net-volume...
I`m wondering if the performance will improve in about 150-180litres (5-6 cubic feet) large enclosures...!? What do you guys think
The JBL E-155 (18"-version...) was used in the cabaret series in a vented enclosure with 283litres (10 cubic feet) net volume...!!
That is more than twice as much, but cone-area of the 18"-model is not even twice as much as the 15" E-145...

Thanks a lot,
Olaf

[maxserg]

I'm not a specialist, but I have 2 boxes of 4,5 cu ft. with K-145 and that this is a compromise for size/basss extension. Personnally I would go for around 8/9 cu. ft. to get moore of the 35/40Hz extension, mine are good to about 40/50Hz. But this is a big size step for only 10Hz in the low. This is an excellent woofer but limited in the lows 30's. Some others could give a moore precise clue

And tue 151 are rare but I guess they are astounding but moore limited in the xover (lower) section.

Good luck!

[Ear4life]

Hello

I think the lowest compromise you can do would be a 6 ft3 tuned to 41 hz. That will keep the speaker within -3 db of its sensitivity from 45 hz and up. It depends on your system (integrated bass speaker with passive filtering, or separate subwoofers with active eq for compensating possibilities). But that should give you a -10 db in the low 30 area with no eq. It´s not a low bass driver, but you can pull a little maybe.

Regards
Martin

[Dr.db]

Hey guys,

thanks for your suggestions

I know the E-145 is not the first choice for very low frequencies, but I like it`s dynamic response.
Actually I do not have the space for a seperate subwoofer, so the E-145 should go as low as they can without compromising it`s fast attacks and natural sound. Decent powerhandling has to be considered as well

I received very kind email`s from the forum-member "Jan Daugaard". We`ve compared a 6 cu ft. simulation with an 8 cu ft. simulation and these did show us nearly the same sensitivity at 40hz and even at 30hz...!!
But why would JBL build an 8 cu ft. enclosure for the Jbl Everest, when there`s no advantage...!?

[Robh3606]

I use a pair in 5 cubic ft. Even in that you need a subwoofer for them. You are better off just droping them into say 4 cubic ft 40hz and putting a sub under them. Watch the Vas number you use the one in the JBL T/S sheets is incorrect. I think the correct value is 428 not 247


http://www.audioheritage.org/vbullet...highlight=E145

Rob

[Dr.db]

Anyone knows the f3 -3db point in the low`s of the Jbl Everest dd55000 ​?

[speakerdave]

Looks to be about 100Hz anechoic and 50Hz 2Pi, if I'm reading the graphs correctly:

http://www.lansingheritage.org/html/...85-everest.htm

[Dr.db]

Thanks...!!
How could I miss these graphs...

Anyway, it really looks like fb3 at 50hz... ain`t low for such a huge enclosure.
But I think it should be allright down to 40hz (-5db).

If I will drive this setup with heavy-bass-music at full power, where at should I set up my highpass-filter ? 30hz, 35hz or even 40hz ?

[speakerdave]

The graphs are also in the thread Rob3606 linked, a worthwhile read.

I'm not the go-to-guy for designing bass reflexes, but--assume the system unloads the woofer below port frequency.

[toddalin]

Ampeg (known for their bass guitar amps) put this driver in at least one of their bass enclosures. You may want to try to find out what volume they used and how they ported it.

http://losangeles.craigslist.org/sfv...167735810.html

[Dr.db]

@ toddalin:

Thanks for your link and the idea behind it
The ampex guitar box has just about 3,5cubicf. of volume and is tuned to 50hz...




When I compare these two JBL simulations, I don`t see the sense in building the huge everest-enclosure:

http://www.lansingheritage.org/html/...85-everest.htm JBL Everest: looks like -3db @ 50hz and -10db @ 35hz in about 227litre enclosure

http://www.jblpro.com/pub/obsolete/l...nclosures2.pdf JBL 4508: looks like -3db @ 45hz and -10db @ 30hz in about 127litre enclosure


If these graphs are correct, the smaller enclosure (JBL 4508) would offer an even better low frequency response. I`m confused...!!

[ratitifb]

Ampeg (known for their bass guitar amps) put this driver in at least one of their bass enclosures. You may want to try to find out what volume they used and how they ported it.http://losangeles.craigslist.org/sfv...167735810.html

thanks for the info
but according to the size of the cabinet we can see i also have some doubts regarding the low bass extension

For E145 load you also have the 4628B Cabaret design as follows (with probably the -3dB @ 45Hz approx.) :

[Dr.db]

JBL 4628 seems to have the same low freq. response as the Everest does.... But with an enclosure half of it`s size

Something must be wrong there!

[ratitifb]

JBL 4628 seems to have the same low freq. response as the Everest does.... But with an enclosure half of it`s size

Something must be wrong there!

different alignments
different surrounding condition spec.

[frank23]

I use the E145-8 in a 4507 cabinet with 2 of the 4 vents blocked. I used to have 2235's in there, and the 2235 do go a bit lower, but I like the sound from the E145 much better. I do not need more bass than the E145 in the 4507 can give, but I can imagine some would like a sub to go with it.

Should you want to see my set setup, I'm only 450km away from Hamburg :-)

I use an M553 active crossover by the way. at 150Hz it crosses to the 2123 and at 1600Hz to the 2420/2344.

By the way, playing Daft Punk over my system, you really do not need more bass, do not think the E145 is bass-shy in a 4507 cabinet...