Zilch's AK Design Collaborative - Econowave Speaker

[jackgiff]

Ok, i`ve been trying to get this project started for a while now and i picked up a pair of L55s off craigslist a couple of days ago. I`ve already given them a couple of coats of dot3 and the bass has improved enormously. I think i will build new cabinets for these drivers as they seem rather small. I am quite suprised by the sound quality of the LE14s. I was expecting a "vintage" sound but they are clear and excellent. The Le20s are not to my taste however and sound distorted at higher volumes. I figure i will build something in the 4-5 cuft range and incorporate the ewave into the cabinet. Can`t wait to get started. Steve.

Hi Steve,

I agree with Zilch's description of the L55 cabinets. I built a pair of specials (4414's?) in L55 cabinets and used the mid, tweet and crossover from a 4412 to replace the LE20's. They are superb, and are still sitting on my main workbench furnishing tunes while I am working on some electronics project.

If you decide to build new cabinets, at least offer the L55 cabinets to someone who is building EconoWaves. I will eventually convert my "4414"s" to EconoWave, unless I can find another pair of L55's. That is a great cabinet if your LE14's are able to flex. Refoam them, and you will be glad you did.

 

[packrat]

Ok, i`ve been trying to get this project started for a while now and i picked up a pair of L55s off craigslist a couple of days ago. I`ve already given them a couple of coats of dot3 and the bass has improved enormously. I think i will build new cabinets for these drivers as they seem rather small. I am quite suprised by the sound quality of the LE14s. I was expecting a "vintage" sound but they are clear and excellent. The Le20s are not to my taste however and sound distorted at higher volumes. I figure i will build something in the 4-5 cuft range and incorporate the ewave into the cabinet. Can`t wait to get started. Steve.

Steve,

I'm doing the same thing - got a pair of L55s last December and am fixing them up bit by bit. You should refoam the woofers - one of my LE14As had soft surrounds and it still had an fs of 80Hz! Both now measure below 30Hz. I ordered surrounds from Rick Cobb and they fit exactly right. I'm waiting for the horns to come in, and new dust caps from JBL (my woofers had the originals pushed in badly). This weekend I'm building the crossovers. My plan was to put the L55s upside down and fasten a board with the horn installed to the original base. Then use another pair of speakers (or bricks) as stands to get the box at least 6 inches off the floor. No more glass top, but it should work. :thmbsp:

 

[Russellc]

Sure am jealous of all you LE14a owners out there. Eventually I will find a pair at the same time I have the spare $.

Russellc

 

[Zilch]

Sure am jealous of all you LE14a owners out there. Eventually I will find a pair at the same time I have the spare $.

Don't pass up any "Hs" or "H-1s" should they happen your way, either, Russell....

 

[Russellc]

Don't pass up any "Hs" or "H1s" should they happen your way, either, Russell....

Will keep an eye open, so far only the 2213H has come to me.

russellc

 

[packrat]

Sure am jealous of all you LE14a owners out there. Eventually I will find a pair at the same time I have the spare $.

Russellc

I've been looking locally for several years and luckily a seller I know decided he needed the storage space more than these. I have thought of eBay but the shipping cost from the US to Canada is kinda crazy.

But, even though the LE14A has been tried out with this (mostly because Zilch and Jack had them?) I've been wondering if the 12" JBL woofers would be better for this - 123A, 122A, the L100T woofer, etc... Heck, I've been looking at all the current pro-sound woofers out there and really wonder if there isn't something in the enormous selection of NEW stuff that would be better than the classic JBLs, and easier to get. Then my mind wanders into dreamland where I'm using an 18" woofer, actively crossed over at 300Hz to a 12" mid-bass, then over to the eco-waveguide....:scratch2:

 

[Zilch]

But, even though the LE14A has been tried out with this (mostly because Zilch and Jack had them?) I've been wondering if the 12" JBL woofers would be better for this - 123A, 122A, the L100T woofer, etc...

Those'll work too, and some E'Wavers have built with them. :yes:

Heck, I've been looking at all the current pro-sound woofers out there and really wonder if there isn't something in the enormous selection of NEW stuff that would be better than the classic JBLs, and easier to get.

Yeah, that too, but generally, prosound woofers have different design objectives, and for extended bass, subwoofer augmentation is required.

There are newer JBL Consumer woofers, too, but at $300 apiece, LE14H-3, for example, moves us well outside the "Econo" realm, if we can even obtain them, and it goes up from there. We use the vintage woofers because they're good, and we can get them. Look to some of the Daytons Gordon and others recommend here for more affordable "new" options.

Then my mind wanders into dreamland where I'm using an 18" woofer, actively crossed over at 300Hz to a 12" mid-bass, then over to the eco-waveguide....:scratch2:

That'll work. Think 43xx large-format Studio Monitors.... :thmbsp:

 

[castlesteve]

Hey thanks for the replies guys. Looks like i should order the ewave parts and work with the L55s until i get a new pair of cabinets together. I will get the new surrounds as suggested and retune the cabinet venting. Maybe a set of legs to get them into better listening position. I`ll post some pics tomorrow as i need to charge the batteries for the camera. I`m playing one of them at the moment on a 9 watt single ended amp and it`s sounding fine with no clipping at all. Very encouraging. You should have seen the basement of the guy i bought them from. He had 4 pairs of JBLs, a pair of AR4s, a pair of ADS and 2 other speaker pairs i didn`t recognise. I thought i had the fever bad! Steve.

 

[Russellc]

Zilch or Jack, a LE14A crossover question:

All this LE14a talk has got me looking at the threads and posts here about that driver. While looking at the "special" crossover for that driver, (900 hz on woofer) I noticed that this version used the same parts selection for the HF that the "over 95 db effeciency" version used.

Without rereading the entire crossover design portion, can someone remind me why this was done? Or am I incorrectly surmising that it is a <95 db woofer?

Thanks in advance,

Russellc

 

[dnewma04]

Good question, as far as I know, you are correct as to the sensitivity being below 95dB.

 

[Kegger]

I wondered about that awhile back myself.

But someone posted a link here not to long ago that showed a bunch of JBL woofers
and it suggested (I believe) the sens was like 93 or 95 on the LE14A.

Andyman is running it with the greater than 95 xover, I do believe though he has that
pad turned towards the down side, so it would tend to have me believe that 94, 95 is
about right as I could not use that high output version with the HPM woofer, the high
end was just too hot and I couldn't trim it back with the L-Pad to match the HPM well.

Cosmos posted the sensitivity was higher then he expected as well, all of this has had
me wanting a pair of these for awhile, if they truly are that sensitive and get the bass,
I'm thinking they can take over as my main woofs with a nice little upgrade! I HOPE!


Only thing I have found is this, which basically shows it as 93, for the H variant, not H1.
http://audioheritage.org/vbulletin/showthread.php?t=10664

 

[dnewma04]

Is JBL playing Klipsch and exaggerating their sensitivities, now? *ducks*



Based on various published T/S parameters, the LE14A is ~92dB 1w/1m or ~93dB 2.83v/1m.

LE14H is marginally less sensitive.

 

[packrat]

Is JBL playing Klipsch and exaggerating their sensitivities, now? *ducks*



Based on various published T/S parameters, the LE14A is ~92dB 1w/1m or ~93dB 2.83v/1m.

LE14H is marginally less sensitive.

Klipsch has nothing on Audio Note for exaggeration - let’s say a 90dB speaker is a 98 dB speaker, is -6db down at 17Hz, and say it works well with a 9 watt amp.... ha!

My LE14A measured 92 db/w/m, and the impedance is pretty much 8 ohms (Re~6 ohms on both). Mms is about 100g on the pair I have, and fs ~ 29Hz (not broken in, and no dustcap yet!). I've found, through looking at the published specs online, that many JBL consumer market woofers are not as efficient as people think (eg. the L300 woofer is also 92-93 dB, not so high considering how large the speaker is). The woofers might have big magnets and large diameter voice coils but they also have coated cones (heavy) and some have pretty low Fs. If you could recone an LE14A with a 50g cone it would easily turn into a 95 to 98 dB speaker, but probably have cone break up to extend the response to beyond 3kHz, like a good guitar speaker has, and no bass below 80 Hz.

This is one reason I was wondering out loud about the high efficiency version, using a 10 or 12 inch pro-sound mid bass unit. Most of these are +95db/w/m speakers, with fs about 50 Hz. They would start rolling off below 100Hz, so a nice 18" woofer in a large cabinet would be needed to match up with it. As Zilch pointed out, you're now looking at JBL 43xx monitors at that point, and $$$$.

Horns arrived yesterday (no taxes, or customs fees either)! I need to make the xover, and then wait for the dustcaps.

 

[Robh3606]

you're now looking at JBL 43xx monitors at that point, and $$$$.

A high efficiency version?? JBL has a ton of those waveguides in SR cabinets.

Where do you want to go with them?? The JBL Large Format Monitors were mostly in the lower 90's sensitivity wise. I think highest was around 96db for either a 4350/55, 4345 or a 4435. There is not all that much of a difference in sensitivity between an LE-14A and a 15" 2235. The real differences are in power handling and X-Max

You don't need 18's for the subs if this is for your living room. You could actually use LE-14 as subs and drop in a 2206 ,or 12 of your choice, between them and the waveguide. You can power the LE-14's with inexpensive PE subwoofer plate amps.

Rob

 

[Zilch]

Without rereading the entire crossover design portion, can someone remind me why this was done? Or am I incorrectly surmising that it is a <95 db woofer?

I have tried them both and confirmed Jack's design. With the low-efficiency version, I run the HF nearly full on, and the high-efficiency one sets the L-Pad south of noon, as Andyman found. I believe we determined the difference between the two is on the order of 4 - 5 dB, and noon is -4 dB on L-Pads.

I'm putting together a switchable sensitivity version of the crossover; the latest PC boards include that option. Seemed like somewhat of a dumb idea 'til I recognized that many E'Wavers are venturing out to try woofers having different sensitivities. Yeah, I'll document that here for anyone to build.

Ideally, it appears that an intermediate sensitivity would be more optimum for LE14A, but the "special" schematic works. Tweakers should look to the results I documented earlier for all of the attenuations Wayne suggested as guidance. The lowpass may change a bit, as well.... :yes:

You could actually use LE-14 as subs.... You can power the LE-14's with inexpensive PE subwoofer plate amps.

I've dropped several hints re: Citation 7.4 but nobody's picked up on that yet.

For 2235H, there's B380, of course.

Easy builds, both of these.... :thmbsp:

 

[dnewma04]

For those considering LE14Hs for subs, you can find signficantly more capable woofers for sub duty and save some serious money in the process. LE14 variants cost too much and are excursion limited, best to save them for what they do best.

If you have them laying around and don't want to spend any more money, then by all means use them. They are fine drivers that can squeak by for sub duty with enough of them.

 

[Russellc]

I have tried them both and confirmed Jack's design. With the low-efficiency version, I run the HF nearly full on, and the high-efficiency one sets the L-Pad south of noon, as Andyman found. I believe we determined the difference between the two is on the order of 4 - 5 dB, and noon is -4 dB on L-Pads.

I'm putting together a switchable sensitivity version of the crossover; the latest PC boards include that option. Seemed like somewhat of a dumb idea 'til I recognized that many E'Wavers are venturing out to try woofers having different sensitivities. Yeah, I'll document that here for anyone to build.

Ideally, it appears that an intermediate sensitivity would be more optimum for LE14A, but the "special" schematic works. Tweakers should look to the results I documented earlier for all of the attenuations Wayne suggested as guidance. The lowpass may change a bit, as well.... :yes:


I've dropped several hints re: Citation 7.4 but nobody's picked up on that yet.

For 2235H, there's B380, of course.

Easy builds, both of these.... :thmbsp:

I may have to try the other crossover on my 2235H drivers, looks like the components in the 4430 LF crossover should work out to 800-900 hz or so, electrically. Dont know what it is accoustically, JBL says 1000.

With the <95 db crossover, Usually have the l-pad in the middle, or just a little to the plus side.

russellc

 

[Zilch]

If you have them laying around and don't want to spend any more money, then by all means use them. They are fine drivers that can squeak by for sub duty with enough of them.

Anyone with LE14s "laying around" needs reacculturation, is what.

[Fortunately, that's what we mostly do here.... :thmbsp: ]

 

[jackgiff]

All this LE14a talk has got me looking at the threads and posts here about that driver. While looking at the "special" crossover for that driver, (900 hz on woofer) I noticed that this version used the same parts selection for the HF that the "over 95 db effeciency" version used.

Without rereading the entire crossover design portion, can someone remind me why this was done? Or am I incorrectly surmising that it is a <95 db woofer?

Thanks in advance,

Russellc

Hi Cody,

The LE14A's are so close to the dividing point, that I chose to use the >95 dB version simply to give some room for both up and down adjustments on the L-Pad. The <95 dB version set it pretty much full scale on the L-Pad, which wasn't comfortable for me. It didn't matter to me whether the extra sensitivity was thrown away by the resistors or the L-Pad.

I recently bought a pair of LE10A's, just because they were affordable, and they are also great woofers. Plus I had a pair of surrounds just laying on the shelf. Or so I thought. Turns out, there was only one. Rick Cobb is now about to send me another pair. I am sure that another project will rear it's ugly head soon using the LE10A's. The pic shows only the right one refoamed, while the one on the left waits for Rick's delivery.

If anyone is looking for a smaller woofer, the LE10A's, H's, or H-1's are extremely nice for E-Waving.

 

[Robh3606]

"Anyone with LE14s "laying around" needs reacculturation, is what."

And I though I was nuts with 3 pairs

Rob