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 :confused:
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 :bouncy:

I received very kind email`s from the forum-member "Jan Daugaard (http://www.audioheritage.org/vbulletin/member.php?8-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/vbulletin/showthread.php?361-The-purpose-of-JBL-E145/page2&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/jbl/specs/home-speakers/1985-everest.htm

[Dr.db]

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

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/msg/4167735810.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 (http://www.lansingheritage.org/html/jbl/specs/home-speakers/1985-everest.htm) JBL Everest: looks like -3db @ 50hz and -10db @ 35hz in about 227litre enclosure

http://www.jblpro.com/pub/obsolete/low_frequency_enclosures2.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. :blink: 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/msg/4167735810.htmlthanks for the info ;)
but according to the size of the cabinet we can see i also have some doubts regarding the low bass extension :crying:

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 :hmm:
different surrounding condition spec. :dont-know:

[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...

[Dr.db]

Hey Frank,

thanks for your reply!

Do you feel the 2235h goes lower at nearly any kind of soundtrack or is it just noticeable at some few, very low tracks ?
Your crossover is very low (150hz). I`m surprised you hear advantages of the E-145 allthough it doesn`t play much of the upper mid-bass.
Does the 2235h really sounds a bit slow ?
Or what is it, what you dislike ?


Thanks a lot...!!

BTW, I`m not living in Hamburg anymore. But thanks anyway for your offer, very kind!

[frank23]

The E145 also does the low end with quite some power. Maybe my low crossover frequency and active crossover makes that I can adjust the E145 level a bit more than someone who uses it to 500Hz or so and is limited by the 500Hz level becoming too high. I felt the 2235 gives a little more shake on very low organ and on the ultimate low of a bass drum on the Sheffield Drum cd. But the E145 came about more musical. It has the same surround and cone profile as the 2123 I use for mid, so maybe there is some magic integration going on there. And the cone is only 55grams whereas the moving mass of the 2235 is about 150grams I think.

There are others here that also went the E145 way and consider it better than the 2235. But the 2235 is a great bass. I still have my pair and would never sell them, even though they are just stored in their boxes. Vertically of course so not to cause spider sag.

In the JBL way of looking at things, they say the E145 is for "producing" music, whereas the 2235 is for "reproducing" music. But JBL has used the E145 in the original Everest so they also thought it suitable for reproduction.

[Dr.db]

Dear Frank,


thanks again for your reply!!
I believe the E145 will sound more musical due to it`s much lighter moving mass and very strong magnet. I was just worried about the low bass in modern music... I actually don`t listen to organ-pipe music, but a lot of electronic-music such as Drum & Bass, House, Techno and sometimes even Hip Hop like Busta Rhymes or Eminem...

BTW, do you drive your system very loud or just at usual listening-levels ?
Where-at do you use a high-pass filter ? At 40 hz maybe?

[frank23]

I play Daft Punk, Rihanna, Steely Dan, Stevie Wonder etc. I have an active 3-way setup with identical Marantz MA24 amps hooked up to all drivers. So 3 left and 3 right for low/mid/high. The MA24 give about 35W each, so a clean 35W is the max I can throw at the E145, and with that it goes very loud. Although because of my active system I can play much louder than people that have a passive system with 3x35=105W of power as possible clipping in the bass does not affect my mid and high.

I have tried to emulate a real drum kit using the Sheffield drum track and asked a real drummer if he thought it sounded life like. He thought it did. Maybe that answers your question about how loud you can play a E145 with 35W :-) But the MA24 Watts are the best 35W or so Watts you can get by the way :-)

My living room is about 75m2, or 200m3. I don't use a low pass, my E145 easily reach down low enough in room not to have to bother with too low freqs not being damped. With 2 holes open, the 4507 ports are tuned at about 30Hz I believe.

[Mr. Widget]

The E-145 will play about about 110dB at 1m in the midband with 35 watts. That's pretty loud.:D

I'm not sure the low end will satisfy all listeners, but in the 60-80Hz to 500Hz region, the E-145 is tough to beat.


Widget

[Dr.db]

Hey,

thanks a lot for your replies guys...!!

You did encourage me to start my project with the E-145 :bouncy:
Even if some few tracks might be missing the very lowest notes, therefor 90% of the other tracks will sound more dynamic and live!
I believe that`s the way to go for me.


I just have to figure out if it`s worth building a 6ft³ instead of the 4,5ft³ enclosure....

[Mr. Widget]

I just have to figure out if it`s worth building a 6ft³ instead of the 4,5ft³ enclosure....I'd buy or borrow a "Woofer Tester 2" and get the actual TS parameters from your pair and run them through a design calculator like BB Pro. You will get a very clear answer to your question.


Widget

[Dr.db]

When using JBL`s Thile-Small-Parametres, is VAS = 428 ?? There is some confusion about this value in the internet....

I doubt I find someone around having a "Woofer Tester2", so I stick to the original TSP´s...

[Robh3606]

so I stick to the original TSP´s...

Which are wrong.

Rob:)

[Dr.db]

Which parameters else than VAS are wrong ??

[Robh3606]

Just the VAS

Rob:)

[Ruediger]

I found a JBL document with a set of TS params which looks reasonable. In the table are other drivers like the E140, so one can compare.

Ruediger

[Dr.db]

Thank you guys.


So when using VAS = 428 I should be allright, correct ?

[Robh3606]

Yes

Rob:)

[frank23]

It has been said that someone at JBL made a typing error. For the E145 they typed VAS=274,7 in the TS sheets, but calculations suggest it should have been VAS=427,7.

[Ruediger]

It has been said that someone at JBL made a typing error. For the E145 they typed VAS=274,7 in the TS sheets, but calculations suggest it should have been VAS=427,7.

... and see what is more plausible.

Somebody should measure it.

Ruediger

[Robh3606]

When you enter the T/S into Bass Box Pro it flags it as incorrect and recalculates it to the correct value based on the other parameters.

Rob:)

[Ruediger]

When you enter the T/S into Bass Box Pro it flags it as incorrect and recalculates it to the correct value based on the other parameters.

Rob:)

... the other parameters are right. Vas is calculated from other params. What if they are wrong?

Someone is needed to bite the bullet and do the measurements. The 2nd paper from Thiele describes how the params can be measured.

Ruediger

[Robh3606]

We have already been through this look at the previous thread. Run it both ways and it's obvious which one is right. Have you actually used E-145's ?? The measured response is more in line with the the higher VAS and the roll off.

Rob:)

[Dr.db]

I just had a look at the newer Everest model, the Everest DD-66000, and compared it`s graphs with the Everest DD-55000 which used the E-145...

Even the newer DD-66000 with it`s two 15" AL1501 with foam surround`s does not go significantly lower than the older Everest with the stiff E-145 :blink:
DD-66000 claims -6db at 45hz and -10db at 32hz.... Looking at the graphs, both systems should have similar low frequency response...
Or am I misstaken ?

http://www.lansingheritage.org/images/jbl/specs/home-speakers/1985-everest/page10.jpg

http://www.jblsynthesis.com/downloads/products/prod_92_634480738986209413_Brochure%20JBL%20Everes t%20Lit%2011%201%2009.pdf

[ivica]

I just had a look at the newer Everest model, the Everest DD-66000, and compared it`s graphs with the Everest DD-55000 which used the E-145...

Even the newer DD-66000 with it`s two 15" AL1501 with foam surround`s does not go significantly lower than the older Everest with the stiff E-145 :blink:
DD-66000 claims -6db at 45hz and -10db at 32hz.... Looking at the graphs, both systems should have similar low frequency response...
Or am I misstaken ?

http://www.lansingheritage.org/images/jbl/specs/home-speakers/1985-everest/page10.jpg

http://www.jblsynthesis.com/downloads/products/prod_92_634480738986209413_Brochure JBL Everest Lit 11 1 09.pdf

It would be said to say that such expensive speakers would need sub-woofer..????

regards
ivica