18" bass bin design for hi fi

[Eduardocastrejo]

Hi, please help me

I want to build a pair of speakers with some vintage lansing parts

I like the idea of compression style like lascala, also I have the plans for diy for la scala series 1, that uses 15" woofer, I only want to use the lascala bass bin design , I dont want to incorporate mid and high inside the speaker cabinet.

but I have a 18" woofers that I want to use

could somebody can gave me an advice for a good bass bin design for hi fi

thanks in advance

18" 16 ohm woofers with jbl 3115 crossover- I dont know the crossover frequency for the woofer , somebody please help me on this ?
2445 16 0hm drivers with 2380 horns crossover 500hz
2404 tweeter 3105 crossover 7000hz

[Mr. Widget]

What is the model number of your woofers? Are you sure they are 18”? Most JBL woofers are not really designed for horn loading.


Widget

[Eduardocastrejo]

Thanks for your answer

18" electro voice ev1
15" are le15a

[Mr. Widget]

I don’t know anything about that Electro-Voice woofer, but the LE15A is best used in a bass reflex design.


Widget

[Riley Casey]

It helps to remember that the early Klipsch bass horns were designed largely to increase SPL in the days of 15 watt amplifiers. The La Scala in particular was a real compromise between size and performance. Modern amps and 18" speakers make possible much more linear designs. 18" drivers were designed to improve low frequency response at the expense of lower midrange response. A smaller cone mid bass driver like an 8-10-12" between the 18 and the compression driver will make for a much better design.

...

I like the idea of compression style like lascala, also I have the plans for diy for la scala series 1, that uses 15" woofer, I only want to use the lascala bass bin design , I dont want to incorporate mid and high inside the speaker cabinet...

[Cyclotronguy]

EV does not as far as I know publish T/S parameters for their drive elements , so if you wish to truly engineer something you will simply have to measure and model. It may or may not be a good candidate for horn loading.

But that said their subwoofers are aimed at the pro-sound market. I suspect you are going to find the Fs for the 18" woofer to be higher than you might expect. That driver is normally used in a vented enclosure and is intend to have a steep high pass filter applied at 35- 40 Hz to limit low end excursion and output.

Cyclotronguy

[Eduardocastrejo]

thanks for your answers

the woofers need to be rebuilt, and the coils are handmade locally, i supose that diferent coils change the parameters of the woofer compared with oem coil
then, after rebuilt what do I need to measure ?
I dont have a lot of options locally, I only know that needs to be 16 ohm to work join with the 3115 crossover ( could somebody tell me what is the frecuency range for woofer with 3115 corssover )
I like the idea of compressed bass bin but if not work properly, and other style like reflex works better, I can change of idea, can be ether 15 or 18" woofers
the room is about 345 ft2 with a height of 8.5 f

this are the specs for the ev 18"
https://products.electrovoice.com/bi...20II%20EDS.pdf

thanks in advance

[retromick]

My new diy subs
2269h in 9.5 cuft enclosurs
ports 2 x 4” x 9.5”

[grumpy]

Nice details!

Your dentist and drywall person should love it

[retromick]

Nice details!

Your dentist and drywall person should love it

Not sure about them, but I’m stoked! Taken me a long time and lots of cash t find my nirvana😎😎😎

[RMC]

EBP = Efficiency Bandwidth Product

This was invented by speaker Engineer R.H. Small as a way to address the suitability issue of a low frequency driver VS the type of system or box to be used: vented, sealed or horn loaded. Easy to calculate: driver Fs/Qes= EBP. Suspension alone doesn't make the woofer, and different suspensions would also change Vas parameter. Many things are involved.

Qes refers to driver's electrical aspect of suspension. EBP is a good rule of thumb, however driver Qts should also be considered as part of the picture. Other aspects can also be taken into consideration, as an example, remember the mention of a foam surround larger excursion driver, where in a horn cab the cone may strike the horn's throat, etc.

Vented enclosure is often a win, to use your own word, JBL considers this as the best compromise among box types. Nevertheless, some drivers are still best used in a sealed sub-box.

From this site, Qes:

"The driver's Q at resonance (Fs), due to electrical losses; dimensionless. "A measurement of the control coming from the speaker's electrical suspension system (the voice coil and magnet). Opposing forces from the mechanical and electrical suspensions act to absorb shock."

[RMC]

I might have a copy of the EV TL-505 plans mentioned in the EV spec sheet. No time to check now but i'll be back later tonight, need to find it in my other computer if have it or not, i think i have it but memory sometimes...

[Mr. Widget]

Personally, I wouldn’t place too much importance on that old crossover. Here is a basic sheet on it, the schematics are also available, but I would suggest selling them and going another route.

http://www.lansingheritage.org/html/...crossovers.htm

Regarding winding a new “16” ohm coil... I imagine you can get a new coil installed and get the woofer working again, but you will really have a lot of unknowns there.


Widget

[Eduardocastrejo]

I might have a copy of the EV TL-505 plans mentioned in the EV spec sheet. No time to check now but i'll be back later tonight, need to find it in my other computer if have it or not, i think i have it but memory sometimes...

I Cant found complete plans

i want to try this old crossovers, if not I already have an old dbx electronic crossover , I dont want to biamp or triamp

i already have reflex speakers, I prefer compression or sealed enclosure

[Anti K]

That's the right thing! Bass 15'', better 2 of them. Sub 18'' (better 2 of them )

How You drive them?

Try what happens closing tubes of upper cabs (15'' sealed then) and active crossing between Upper Cab and Sub around 90...70Hz.
Should make low end very concrete.