Zilch's AK Design Collaborative - Econowave Speaker

[Zilch]

I generally don't put too much stock in enclosures being too big. I prefer them 'too big' most of the time. EBS alignments are some of my favs and that is an alignment that uses an enclosure that is oversized and tuned deeper. They work great at producing very extended, tight bass. I've read those comments myself about the 19s but have always walked away a little baffled by them.

http://audioheritage.org/vbulletin/showthread.php?p=138472#post138472

http://audioheritage.org/vbulletin/showthread.php?p=138477#post138477

We don't have "official" T/S parameters for 416A/Z, which is why I suggest measuring them.

Working with what I did have available indicated that EBS was an appropriate alignment for 416Z, as I recall.... :yes:

What I've read about the Onken cabs is they are "tighter" bass than a sealed or vented cab of the same size. It's worth a try though.

There may be an advantage to oversize ports and huge duct volumes.

Enthusiasts are also notorious for making stuff up....

 

[dnewma04]

I understand what you were doing, you just took a different approach then I would have. I would have tuned deeper to loose the hump in the bass response because of my preference for that sound. I don't like the idea of giving up cabinet volume, generally. That said, I would almost guarantee that I would prefer either of methods to the little bump the altec guys employed but only because I grew up in the age of t/s. All i've known since I got in the hobby are things like maximally flat, critically damped, EBS, etc. I bet the Altec guys were going for a sound they deemed accurate and realistic and I wouldn't be surprised if they tried tuning with a number of port lengths before deciding on that one. Based on the success and popularity of the 19, I think they hit the mark.

As far as the onken goes, there is an advantage to more port surface area but its a balancing act. Too much area and it gets long enough to start acting more like a pipe and less like a ported enclosure. Onkens look nice and with certain cabinet volumes/tuning freq make large ports more viable, they inherently provide more bracing than more common construction methods and if I didn't mention it they look cool. Maybe they sound tighter to some people that compared them to ported boxes without adequate bracing? or inadequate port area? I don't put too much stock in those kind of subjective impressions without more info about what was compared.

 

[nerdorama]

Eminence Beta 8 inquiry

Hi Ewaver's,

Wondered if anyone has personal experience or any other comments regarding this driver. Gary Pimm, of tube amplifier fame, wrote somewhere about a speaker he built using a pair of these in an EBS alignment (4.25 cu ft, 40Hz tuning). The lower woofer he rolled of early so it only augmented the bass. He also used a .4mH coil in series to trim the rising hi end.

This seems like it might be a good match for the Ewaveguide and I have some empty cabinets that are just about the right volume.

Thanks for any comments.

John
DIY tubes for music, Yamaha for fun
CA-1010, CR-1000, CR-1020, CR-820, CR-620, CR-440
M-80, R-2000, R-700, CR-840, A-960II, A-500, A-100a
AX-596, CT-810, T-7, T-1060, NS-500

 

[Zilch]

Working with what I did have available indicated that EBS was an appropriate alignment for 416Z, as I recall....

As y'all might have known I would, I looked it up. The analysis begins at Page 42, Post #622 of the "Babies" thread:

http://audioheritage.org/vbulletin/showthread.php?p=162781#post162781

With the available T/S parameter provided there, Valencia is an EBS tuning, and the efficiency of the the system is artificial, at the expense of bass response. Expanding the cabinet volume does NOT "fix" it.

Whether those findings are correct or not is indefinite, but we subsequently installed 2235H in a pair of Valencias, and even without optimizing the tuning, full-blown bass response "magically" appeared.

Yo, ANDYMAN, heads UP! :yes:

 

[Kegger]

So are we saying pretty much any cabinet arrangement we won't be getting good, deep,
solid bass with that Altec woofer? That sucks, I like the sound of the bottom half on the
speakers of Andy's but a bit deeper/lower is what I'd want from them, seems pretty funky
to have to add a subwoofer to a 15" woofer'd speaker with a big ole cabinet!

Any tricks that could be done, a different type cabinet approach or just no can not do it?

 

[Zilch]

Any tricks that could be done, a different type cabinet approach or just no can not do it?

Mind the caveat: we don't have unequivocally good T/S parameters on 416A/Z; that's just what those we DO have tell us: it's a midbass driver.

[Rant]It's STOOPID, and typical of the status of knowledge regarding Altec components and systems. I don't give a flinging whit about Altec stuff. Why is it ME the only one apparently willing to actually figure it out?

This post by Moldyoldy sums it up:

http://audioheritage.org/vbulletin/showthread.php?p=161840#post161840

It's a cult, is what.... [/Rant]

Bottom line, we don't know until someone undertakes to measure a bunch of 416Zs and get accurate and reliable T/S data.

Do they work in bass horns?

Compenstation knocking down the rising response will restore reasonable balance, but you sacrifice efficiency. Notice that, in the Valencia alignment, that's about what installing 2235H instead does. With that driver, though, there's the potential of retuning for even more extended LF response.... :yes:

 

[dnewma04]

According to GPA, 416B and 416Z have identical T/S parameters. If this is true, 10 cu feet tuned to 25hz looks outstanding. It's got an F3 of 57 hz, but is basically shelved at that level all the way down to 25 hz without losing much output. F6 is at 25 hz. Excursion is safe up to approx 75w before you start pushing safe limits. In room, I would expect you to get very deep bass extension into the high teens or low 20 hz range.

If you don't have subs available, this the route I would take. If you do have subs, the Altec woofers mounted in a 4.75 cu ft box tuned to 42 hz looks promising if you don't want to lose a db or two of sensivitity around 80-130hz or have space limitations.

The 416 on paper seems to model very closely to the LE14H in similar type alignments. (doubling standard ported volume requirements and dropping tuning down to 22-25hz range). Why is the LE14H a very good subwoofer and the Altec not capable of creating acceptable bass when they model almost identically outstide of sensitivity where the Altec will make the same amount of bass in 2x the enclosure and half the power?

416Z in 10 ft^3 tuned to 25 hz

416z in 4.75 ft^3 tuned to 42hz

Outside of the impedance plot and high power, high SPL applications, I prefer the bigger box. Of course, this also assumes that GOAs comments are correct and the 416B and 416Z do have the same parameters.

 

[Steve O]

According to GPA, 416B and 416Z have identical T/S parameters. If this is true, 10 cu feet tuned to 25hz looks outstanding. It's got an F3 of 57 hz, but is basically shelved at that level all the way down to 25 hz without losing much output. F6 is at 25 hz. Excursion is safe up to approx 75w before you start pushing safe limits. In room, I would expect you to get very deep bass extension into the high teens or low 20 hz range.

If you don't have subs available, this the route I would take. If you do have subs, the Altec woofers mounted in a 4.75 cu ft box tuned to 42 hz looks promising if you don't want to lose a db or two of sensivitity around 80-130hz or have space limitations.

The 416 on paper seems to model very closely to the LE14H in similar type
alignments. (doubling standard ported volume requirements and dropping tuning down to 22-25hz range). Why is the LE14H a very good subwoofer and the Altec not capable of creating acceptable bass when they model almost identically outstide of sensitivity where the Altec will make the same amount of bass in 2x the enclosure and half the power?

416Z in 10 ft^3 tuned to 25 hz

<snip other images>

416z in 4.75 ft^3 tuned to 42hz

<snip other images>

Do my eyes deceive me or are the plots at 25Hz and 42Hz the same.

Steve O
Still lurkin n' learnin

 

[dnewma04]

Oops! I copied the wrong link. Will edit.

Thanks!

 

[Zilch]

COOL! I also ran models of 416-8C in Valencia volume here on AK, and found it to be an excellent performer.

http://audiokarma.org/forums/showthread.php?p=1432063#post1432063

The key to this is whether T/S parameters for 8A/Z and 8B are the same, or at least similar.

Jack has three pair of Valencias, and while he's not set up to measure T/S parameters, we may be able to talk him into doing some nearfield LF RTA curves for us to verify. We figured 846B volume at 5.233 cuft. net, and the stock tuning at 35.8 Hz. He did post Valencia measurements earlier in this thread, but they are not nearfield.

Anybody else have 416-8Zs and some measurement gear?

Post the 416-8B T/S parameters you're using, please, Dave, and the source, for comparison.... :yes:

 

[dnewma04]

The 416-8A appears to be a very different beast from the 416-8B.

The comment about the B/Z being the same was from a speaker building friend who was given that info by someone at GPA. I can vouch for my friend, I can't vouch for who he spoke with, so I'm just making some assumptions, here.

416-8B(Z)

Fs 25.00 Hz
Re 8.00 Ohm
Qms 7.00
Qes 0.29
Sd 890.0 cm2
Vas 377.0 l
Xmax 5.00 mm
(Le) 2.40 mH
P 100.0 W
Qts 0.278
Mms 119.62 g
Cms 0.339 mm/N
Rms 2.684 kg/s
Bl 22.76 Tm
SPL (1w/1m)94.7 dB


416-8B from www.thielesmall.com

Vas 749.6
Qts: .31352
Qes: .33
Qms: 7.05
Sensitivity 1w/1m 98
Power: 100w
xmax 3.8
Moving mass 59.48g
Disp area 890cm^2
BL 14.005

This was linked to the following chart of t/s parameters.

http://web.archive.org/web/20051030025046/alteclansingunofficial.nlenet.net/Thiele-Small.html

There are certainly some discrepancies from source to source that could make a huge difference.

 

[Zilch]

Indeed, that's the level of chaos I encountered trying to suss it out. From the links I posted, 416-8A and 416Z are allegedly the same driver, used in Valencia et.al., 416-8B is the Model 19 woofer, and 416-8C is the ferrite-magnet version of 416-8B.

 

[dnewma04]

In any case, I tended to fine the alignment of the Altec 19 in the bigger box to be a curve i'd be more interested in pursuing, just tuned deeper. Maybe we can convince someone with some original Vals and 19s to send you a woofer? Or I'll just buy a woofer tester to get some quick TS parameters.

 

[Zilch]

Or I'll just buy a woofer tester to get some quick TS parameters.

That's the better idea. My data is plastered all over the internet. It'd be good if it were independently verified or contradicted.... :yes:

 

[GordonW]

Whether those findings are correct or not is indefinite, but we subsequently installed 2235H in a pair of Valencias, and even without optimizing the tuning, full-blown bass response "magically" appeared.

Same seems to apply to the (ostensibly similar) Altec 411, in a Valencia/Heathkit AS101 cabinet. Boy, does it have LOW BASS. 30 Hz no problem!

Regards,
Gordon.

 

[Andyman]

So how were the mids? Were they as sweet as with the Altecs? I'd like more bass, but not sure I'm willing to lose the mids in the process. More guitar here than pipe organ

 

[djnagle]

Hi All, I have a problem. I am messing with my system...AGAIN, and I have my Adcom hooked to my Jensen Imperial bass bins, my 300B hooked to my EWG running the 210, and my Heil tweets hooked to my digital amp. All of this is running through a seperated passive crossover. The highs are unbelivable, the lows are increadable, but the mids coming through the EWG get highly distorted on the energy peaks. Happens on both channels. My 300B is 16ohms and the EWGs are 8ohms. What gives? Cheers.

 

[Zilch]

My 300B is 16ohms and the EWGs are 8ohms. What gives? Cheers.

What's the "separated passive crossover?" What frequencies? At what impedance?

I have no clue what a 300B is, but if it's rated at 16 Ohms, and you're running an 8-Ohm load on it, there's not much mystery here....

So how were the mids? Were they as sweet as with the Altecs? I'd like more bass, but not sure I'm willing to lose the mids in the process. More guitar here than pipe organ

It's a good question, and always an issue. There's not many 15" woofers that will play extended bass and mids well concurrently, and they all have limits.

2235H in 4430 is crossed at 1 kHz. Does that work? Yup, but it's a stretch.

416-8B is the woofer in Model 19, no? Does that work crossed at 1.2 kHz?

I have no experience with the Altec 411 Gordon mentions.

 

[dnewma04]

Do the right thing, Andy...add a subwoofer or two....or three.

What's the "separated passive crossover?" What frequencies? At what impedance?

I have no clue what a 300B is, but if it's rated at 16 Ohms, and you're running an 8-Ohm load on it, there's not much mystery here....

300B is a tube and it sounds like he only has a 16 ohm secondary on his output transformer.

It's a good question, and always an issue. There's not many 15" woofers that will play extended bass and mids well concurrently, and they all have limits.

Bass extension would be limited to 35hz range, maybe a little lower in room but....

 

[Kegger]

If it were me and I was going to be building the new cabs anyway an the woofer will do
as what Dave has posted the graphs for, Hell Fire I'd do it! What 10 cu ft tuned to 25hz?

I'd mount the woofer on the back side of the front baffle (1" thick) mount the guide on
the front lined right up to the egde of the woofer opening an that would probably be the
most butt kickin Altec woofer 2-way on the planet!:guitar:

You'd get the Altec woofer sound cause your using the darn thing, only thing you'd loose
is the PA type bass that kinda falls out of the Altec cabinet...