conjuring deep bass from E145 in a huge enclosure

[johanwholst]

After playing with E145 for a while, I concluded that iit s my favorite driver despite lack any significant output under 50hz in my 140L (4.5cuft) test cabinets
Im now contemplating building cabinets at 300L net (10cuft) tuned to 30hz, a bit under the resonance frequency of 35hz. I am using a DSP solution.
Any reasons not to go ahead with this project? Can a cabinet for these drivers ever be too big (wife's opinion not included)?

[JoeNelis]

I say if your ears are happy go for it. thats what audio is about.

[johanwholst]

I say if your ears are happy go for it. thats what audio is about.

Sure, I really like what I'm hearing from E145 in a smallish 140l cabinet, but a box twice the size is quite a built, and I'm wondering how the large volume and relatively low tuning can affect the general sound and transient response of the woofer
Its not built in a day either...

[johanwholst]

This is my initial idea
Waveguide is M2, but I'm working on the idea of making the front baffle detachable for testing different horns



JBL M2 as comparison

[srm51555]

Johan, sounds like it would be a cool build. Looking forward to see what you come up with.

[grumpy]

Everest went ~8ft3

http://www.audioheritage.org/html/pr...bl/everest.htm

[mantisory]

Looks like an interesting project. I currently have my 145's mounted in 4560 cabinets. I have them cut off at ~90Hz so I don't have to deal with the crazy response below that (the main reason, I think, that people dislike the 4560). Below that I use a Fitzmaurice THT
Anyway, I wonder what the difference would be, moving them from a mid-bass horn to a bass-reflex unit like this...I really like the way they sound now, but the could definitely use an asthetic upgrade
Byron

[johanwholst]

Everest went ~8ft3

http://www.audioheritage.org/html/pr...bl/everest.htm

Okay, so I'm not totally off. Will probably end up with a net volume at 9cuft after some slight modifications and bracing.

Ill try to figure out a cabinet that's aesteticly acceptable, with good material utilization, and preferably modular if I can find a slick way of doing it.
Will use the same bracing structure as in M2 and most likely 1"mdf.

[Ruediger]

The E145 has these parameters:
fs = 35 Hz
Qt = 0.25
Vas = 275 liters

The 1st design which fits is a QB3 (Quasi Butterworth):
f3 = 62 Hz
Vb = 62 liters

The 2nd is a B6 and requires an electronic filter:
f3 = 35 Hz
Vb = 100 liters

The Qt of the E145 must be increased for a fit. The unwanted DC resistance of basscoil in the xover and in the cables can do that (if properly calculated).

Also you can use the above parameters as a starting point and vary them, see what results.

I do not have a design program, perhaps somebody with a program can run a simulation?

ruediger

[johanwholst]

The VAS in the JBL T/S is probably wrong, and I have seen claims that it should be 427 Litres.

[rusty jefferson]

The E-145 is the woofer used in the 801c coaxial driver used for the UREI monitors. The 813c and 815c have (I think) approximately 11/15 cubic ft boxes and helper woofers. I don't know if the crossovers in those models have a compensation to relieve the E-145 of low bass, but those speakers are quite (deep) bass shy unless soffit mounted (as designed) or heavily eqed (very common in the time they were popular). The E-145 is an amazing midwoofer. Keeping the boxes you have and building subwoofers may give more satisfying results?

[Ruediger]

The VAS in the JBL T/S is probably wrong, and I have seen claims that it should be 427 Litres.

427 Liters is about the value for the E155. Somebody should measure that

Anyway: using 427 Liters as the Vas for the E145 results in the following cabinet sizes:
for the Qb3: 96 liters
for the B6: 156 liters

ruediger

[Hoerninger]

An active filter can be found here on page 12/13
http://www.xlrtechs.com/dbkeele.com/...estatement.pdf
and lots more of info.
__________
Peter

[Robh3606]

Hello

I have been using E-145's for years. They are a fine sounding woofer but they simply are not going to give you solid bass below 40Hz. I have used mine crossed at 80 Hz to subs. Mine are in 5 cubic ft, enclosures with 2235's under and it's a winning combination. The 2235's are in B380 clone cabinets as far as tuning with a BX-63 providing the LF boost at 26Hz.


Rob

[badman]

I agree about trying too hard with a driver not meant for deep bass. You'd be better off choosing a different option for the deep stuff- if enclosures that big are an option, perhaps multi-subs are instead? Multiple in-room subs proper distributes modal behavior better than single large enclosures, and will give you more output, deeper, with smoother response and higher output capability (and lower distortion) than you could ever hope to achieve with funky alignments.

Cost no option, Rhythmiks are very punchy, clean subs and would be great choices, but a nice benefit of multiple subs is the lowered requirements of each individual unit- you could go with inexpensive units from parts express, or DIY them. Audiokinesis also has a nice "swarm" sub arrangement though IMO it's overpriced at 3k, and I'd rather go with a few of these http://www.parts-express.com/dayton-...oofer--300-634 or their 12" brethren.