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Dr.db
05-02-2014, 07:29 AM
Hey,


I just had a look at the Altec frontloaded-bassreflex enclosure`s which might be an appropriate housing for my JBL E-145. :bouncy:

http://blog-imgs-55.fc2.com/a/u/d/audioelex/816A_1.jpg

http://www.voiceofthetheatre.com/images/828H.1.jpg

As far as I can tell, both enclosure`s seem to have the same frontloaded horn.
They just differ in the size of the bassreflex-volume...
816A hornloading starts at 200hz, this seems to be reasonable as the JBL 4560 has similar dimension and cutoff frequency of 200hz...
But the 828H is claimed to start hornloading at 120hz...!! But the horn ain`t bigger, how is that possible :confused:



Thanks a lot and sorry for comming up with these many threads lately,
Olaf

NickH
05-02-2014, 12:38 PM
The top and bottom panels on the horn of the 816 are parallel which is supposedly bad. That is not the case for the 829. The bottom panels is angled downward.

as for putting e145's in them, can't tell ya. I'm sure it would make some kind of noise, lol.

I would build something on the lines of an 815 horn. But its much larger and sealed back chamber.


Oh the radius on the horn flare of the 816 and 829 is the same. Just shy of 32 inches I believe.



Hope this helps a little. Lucky guy for having e145's too. I wish I had 4 for my bass horns.

Nick

Dr.db
05-02-2014, 03:55 PM
Thanks, you are right!!

The 816`s top and bottom panel is straight were as the 828`s bottom panel is angled downward :)

So the actual horn-mouth of the 828 is about 3inches higher/bigger. But they`re both 30inches wide and 14inches deep.
This couldn`t lead to an insomuch deeper cutoff of the horn, could it ?

Horn Fanatic
05-04-2014, 06:30 AM
The top and bottom panels on the horn of the 816 are parallel which is supposedly bad. That is not the case for the 829. The bottom panels is angled downward.

as for putting e145's in them, can't tell ya. I'm sure it would make some kind of noise, lol.

I would build something on the lines of an 815 horn. But its much larger and sealed back chamber.


Oh the radius on the horn flare of the 816 and 829 is the same. Just shy of 32 inches I believe.



Hope this helps a little. Lucky guy for having e145's too. I wish I had 4 for my bass horns.

Nick

The best choice of JBL driver for either of those boxes would be the 2220A. I don't consider the K/E145 a good choice as a horn loader. What you need in a straight axis horn is what would be considered a full range driver. The 145 series do not fall into that category. With the 816 you're going to encounter standing waves a bit above 400Hz, but I don't consider it a problem. It's my feeling you will have better bass response with the 816. IMHO, the 825 (A7) is a box for some reason, which makes for an awful home system. For having a volume of approximately ten cubic feet, the bass sure sucks. I know, and have read about folks massaging the A7 to no avail. There is something fundamentally wrong with that box for use other than a 1940's movie theater. That goes for the JBL 4560 as well.

When I worked at ALTEC the company had a small listening room which had a two corner horns. Now, before you say that ALTEC never had a corner horn, you'll be interested to know that back then the corner horn consisted of four 816 boxes in each corner facing into a corner reflector. I have to say, the system sounded awesome. When the Stanley Screamer systems were introduced the corner horns were replaced with the SS single bass reflex enclosure which was loaded with the 4218H II if I remember correctly.

If you use a pair of 816 per side, what you essentially have would be the ALTEC 820 bass section. On that note, the JBL C31 which should have been worthy contender to the 820, suffers from a sever tuning problem. The bass response from that box is very disappointing, not to mention the poor choice of the high frequency component. However, it's the C31 I would chose over the 820 primarily because of the divergent panels, but only after proper tuning and substitute of the H.F. section that makes more sense.

Horn Fanatic
05-04-2014, 06:42 AM
Thanks, you are right!!

The 816`s top and bottom panel is straight were as the 828`s bottom panel is angled downward :)

So the actual horn-mouth of the 828 is about 3inches higher/bigger. But they`re both 30inches wide and 14inches deep.
This couldn`t lead to an insomuch deeper cutoff of the horn, could it ?

The 816 mouth area is approximately 440 square inches. The mouth area of the A7 is approximately 540 square inches. Since the fc between the two with respect to their nearly identical lengths would be negligible to the human ear, it's unlikely that anyone would tell the difference between the two, but I feel the 816 is the better choice. It's not sub-woofer material, but neither is the A7. I don't think the A7's twice cubic volume of an 816 in a living room is worth the poor bass response it delivers. Then you have the SAF to consider.

Horn Fanatic
05-04-2014, 06:58 AM
The top and bottom panels on the horn of the 816 are parallel which is supposedly bad. That is not the case for the 829. The bottom panels is angled downward.

as for putting e145's in them, can't tell ya. I'm sure it would make some kind of noise, lol.

I would build something on the lines of an 815 horn. But its much larger and sealed back chamber.


Oh the radius on the horn flare of the 816 and 829 is the same. Just shy of 32 inches I believe.



Hope this helps a little. Lucky guy for having e145's too. I wish I had 4 for my bass horns.

Nick

The best choice of JBL driver for either of those boxes would be the 2220A. I don't consider the K/E145 a good choice as a horn loader. What you need in a straight axis horn is what would be considered a full range driver. The 145 series do not fall into that category. With the 816 you're going to encounter standing waves a bit above 400Hz, but I don't consider it a problem. It's my feeling you will have better bass response with the 816. IMHO, the 825 (A7) is a box for some reason, which makes for an awful home system. For having a volume of approximately ten cubic feet, the bass sure sucks. I know, and have read about folks massaging the A7 to no avail. There is something fundamentally wrong with that box for use other than a 1940's movie theater. That goes for the JBL 4560 as well.

When I worked at ALTEC the company had a small listening room which had a two corner horns. Now, before you say that ALTEC never had a corner horn, you'll be interested to know that back then the corner horn consisted of four 816 boxes in each corner facing into a corner reflector. I have to say, the system sounded awesome. When the Stanley Screamer systems were introduced the corner horns were replaced with the SS single bass reflex enclosure which was loaded with the 4218H II if I remember correctly.

If you use a pair of 816 per side, what you essentially have would be the ALTEC 820 bass section.

Dr.db
05-04-2014, 02:08 PM
The 816 mouth area is approximately 440 square inches. The mouth area of the A7 is approximately 540 square inches. Since the fc between the two with respect to their nearly identical lengths would be negligible to the human ear, it's unlikely that anyone would tell the difference between the two, but I feel the 816 is the better choice. It's not sub-woofer material, but neither is the A7. I don't think the A7's twice cubic volume of an 816 in a living room is worth the poor bass response it delivers. Then you have the SAF to consider.


But why does Altec claims the A-7 starts hornloading at 120hz where as the 816 is claimed to be 200hz...!??

http://www.voiceofthetheatre.com/images/828H.1.jpg

Thou your eplanation sounds reasonable I have to admit.... ;)



BTW;
does the frontloading of the 828 affect the drivers operation in that bassreflex-rearchamber at all ?
Does it operate the same way as in a simple bassreflex-enclosure except for an additional emphasis in the midrange ?
So if considered absolutely and not relatively, maximum lowbass will be similar in both enclosures, right !?




Unfortunatelly I havn`t got two useful corners to place 820`s or C31....

I also think JBL 2220 would be a little more suitable for hornaplications. But the E-145 was used in the Hartsfield as an replacement-speaker and was used in the 4560 and 4550.

NickH
05-04-2014, 04:13 PM
Hey Horn Fanatic,


I agree that the 2220 is a excellent driver for horn loading. But I can't see how you say the k/e 145's are not. There direct descendants of "THE BASS HORN DRIVER" the 150-4. They've got all the horn loading goods like ultra lite cone and powerful motor. Plus a low qts and high fs. All properties you want in a horn driver.

But I'm no expert. But I've certainly seen many in horns. Shoot if I had 4 they would be in my horns.


Nick

Mostlydiy
05-04-2014, 10:58 PM
Hey Horn Fanatic,


I agree that the 2220 is a excellent driver for horn loading. But I can't see how you say the k/e 145's are not. There direct descendants of "THE BASS HORN DRIVER" the 150-4. They've got all the horn loading goods like ultra lite cone and powerful motor. Plus a low qts and high fs. All properties you want in a horn driver.

But I'm no expert. But I've certainly seen many in horns. Shoot if I had 4 they would be in my horns.


Nick

If you are to believe the JBL TS sheet the 2220 is way better. The only thing that the E145 has thats better is lighter cone. The 2220 has higher fs, lower q, lower LE and way highter BL. As a matter a fact the E145 doesnt look like a very good horn loading candidate at all looking at those specs. In theory that is, in practice it might be another matter.

Dr.db
I think it would be better if you built your own mid bass horns and worked out another solution for the sub 100Hz frequencies.

Maybe something like this? This guys homepage was a catalyst for my own project startup.

http://www.volvotreter.de/index.htm

/Mostly

Horn Fanatic
05-05-2014, 03:35 AM
Hey Horn Fanatic,


I agree that the 2220 is a excellent driver for horn loading. But I can't see how you say the k/e 145's are not. There direct descendants of "THE BASS HORN DRIVER" the 150-4. They've got all the horn loading goods like ultra lite cone and powerful motor. Plus a low qts and high fs. All properties you want in a horn driver.

But I'm no expert. But I've certainly seen many in horns. Shoot if I had 4 they would be in my horns.


Nick

Hi Nick -

Wow! a lot of questions. :-)

The initial criteria I consider, but not the only, is the Efficiency Bandwidth Product, fs/Qes. The EBP for the E145 is 134. Good, but not great. The EBP for the K145 is 116. Dismal, and best suited for a large vented enclosure. The EBP for the 2220A is 194, and for the 2220H is 205. The 2220A and 130A T/S parameters are identical down to the last number, with the advantage going to the 2220A due to the linen surround. And yes, the E145 does have the lighter cone, but the EBP doesn't blow my hair back.

Calculations through the horn design program I wrote indicate the higher the EBP, the smaller enclosure that is required. The DCR is also a factor. I typically chose to design for bandwidth at 50% efficiency, which calls for a smaller throat and volume. If greater efficiency is the goal, then a larger throat and larger cavity would be in order. This is where the ALTEC enclosures come in. The throat area and cavity volume are interrelated, which is important in order to achieve proper reactance annulling. As much as I like ALTEC speakers, none of them work well in very small enclosures. I can't see designing a compression or rear loaded folded horn enclosure for ALTEC drivers which require at least half the volume of an A7.

With respect to a rear loaded horns such as the C34, C40, 4530, 4520, the cavity acts as an acoustical low-pass filter. The larger the cavity, the larger the throat translates to a lower upper frequency roll-off frequency. If you read the data for the 4530 & 4520, you will notice where is reads that the speaker acts as a direct radiator above 150Hz. I loaded a 2220A into a Klipschorn several years, and was quite impress with the results. The cavity volume and throat area were right on the money. I also loaded a K-Horn with the EVM15L, and it too performed admirably. I think that driver would work very well in an 816 or A7 also.

I know the 2205 driver was offered in the straight axis and rear loaded horn theater boxes, but with an EBP of 136 I feel the 2220 is still a much better choice. As far as the K/E 145 being a direct descendant of the 150 series. I won't be convinced of that until someone produces the T/S parameters for the 150 to prove if it is in fact, similar to the 145. IMHO, the 150 was the best horn loader ever produced, however I have not had any experience with the Tannoy's. I'll always hold re-coned 150-4C's I see on Ebay suspect, as no one has ever provided data to demonstrate re-cones share the same T/S parameters. There are one or two chaps on Ebay who are producing counterfeit 150-4C's, as well as the 375 Bubble Backs. If I could get my hands on an E145 for evaluation I would be as happy as a clam on a wet beach. However, as I would be at the mercy of price and availability of vintage cone drivers, I'd rather not design my products around them. I'm looking at other manufacturers of current production models for my horn drivers, and believe me, there aren't many.

Why JBL saw fit to load the later model Paragon with the LE15 mystifies me, because it's the last driver I would consider using in a horn enclosure. I had the opportunity to reload an LE15 Paragon with the 150-4C, and the difference was startling. As far as I'm concerned due to my musical background as an electric bass player, putting an LE15 in a Paragon will produce mushy, inarticulate, ill-defined bass, flawlessly. The 2220 should have been the driver substitute. I'm just glad the Hartsfield didn't suffer the same fate.

I hope I have been of some assistance,

H.F.

P.S. I don't call myself Horn Fanatic for nothing. I would highly recommend that if you're really interested in bass horns, and have the facility to build them, you should design your own. It's not a simple task, but it's not rocket surgery either. If there is anything I can do to help you on your way, don't hesitate to ask.

Horn Fanatic
05-05-2014, 05:05 AM
But why does Altec claims the A-7 starts hornloading at 120hz where as the 816 is claimed to be 200hz...!??

http://www.voiceofthetheatre.com/images/828H.1.jpg

Thou your eplanation sounds reasonable I have to admit.... ;)



BTW;
does the frontloading of the 828 affect the drivers operation in that bassreflex-rearchamber at all ?
Does it operate the same way as in a simple bassreflex-enclosure except for an additional emphasis in the midrange ?
So if considered absolutely and not relatively, maximum lowbass will be similar in both enclosures, right !?




Unfortunatelly I havn`t got two useful corners to place 820`s or C31....

I also think JBL 2220 would be a little more suitable for hornaplications. But the E-145 was used in the Hartsfield as an replacement-speaker and was used in the 4560 and 4550.

Hiya Doc -

If you convert the A7/828 mouth area to a circle, the circumference would indicate that the lowest frequency of support (not to be confused with fc) in free air is approximately 165Hz. For the 816 it would be approximately 182Hz. Below those frequencies is where the horn begins to unload.

There is a logarithmic equation based on the throat area, mouth area, and the total horn length used to determine the flare rate, but it wouldn't be accurate in the case of the A7 & 816 because the curves are a radius, not a true exponential flare, which means the figure for the flare rate is essentially thrown out the window. The best that can be done to determine where the cross section >> approximately << doubles that of the throat area is to figure out at what distance from the throat that area lies. But using that data to determine the flare rate is just a guess. To design an exponential horn one must know the fc, which the flare rate is calculated from, and the throat area. The formula for an exponential flare will then give you the length at which the throat area approximately doubles. You'll notice that the distance between the successive doubling of the area decreases as the horn gets longer. For more control over the design parameters I prefer to use Vincent Salmon's Hyperbolic equation. A bit more complicated, but more flexible than the standard exponential. The Jensen Hypex horns were all based on Salmons equation.

"does the frontloading of the 828 affect the drivers operation in that bassreflex-rearchamber at all ?"

As I mentioned in my reply to Nick, the throat area and chamber volume are interrelated. They don't affect each other so much as interact when the impedance of the acoustical mass reactance of the throat is at unity with the impedance of the acoustical reactance of the chamber compliance. Consider those two elements as an electrical analogy. The acoustical mass of the throat would be considered an inductance, and the acoustical compliance of the chamber as a capacitance. It's simple filter math after that. It's the frequency calculated that determines where the horn and chamber act as one. Think of the system as a first order cross over filter, and keep in mind that above and below that frequency is where the horn and rear chamber function in their own separate frequency domains, as your typical 6dB/octave filter operates. Below the usable frequency range of the horn the system is your basic (phase inversion) bass reflex box.

As I mentioned in another post, I feel the A7 has poor bass response compared to the 816.

As for the 145 used in the C30, I would need to run calculations on the 145 to determine it's viability in that enclosure. Look at it from my perspective. Did JBL recommend the 145 because is was suitable, or because it was a 15" driver? The E140 would definitely have been out of the question, but the E130 could have been a contender. The recommendation to use the 145 could have been a matter of situation and motive.

I hope I have been some help,

H.F.

Dr.db
05-05-2014, 08:11 AM
Hey Horn Fanatic,

I really do appreciate your effort you put in these answers!! :applaud:

Did I get you right, when I say the 828 will act under their hornloading of 165hz exactly the way a simple bassreflex-enclosure would ?
Just above that frequency, when the horn starts loading, the horn will interact the function of the bassreflex-chamber due to impedance, inductance and capacitance change...!?

But this would dissent to your statement the 816 (with smaller bassreflex-chamber) actually has a better low end, so I might got you wrong...!?
What`s precisly "better" with the 816`s bass response ? Is it louder in the midbass (80-150hz) or does it reach lower frequencies ?

I understand the mentioned drivers are better suited for horns than the E-145...
Allthough I know x-max ain`t a major property for horn-applications, I thought the extended x-max of the E-145 of 7mm could be quit usefull in the 828 due to the fact it is operating in a bassreflex in the lows, not a horn...
If it`s just for me, you don`t have to trouble yourself with checking E-145 for the JBL scoops, but thanks a lot.
Im rather not interested in the rearloaded/front directradiators due to their phase-dip in the mid bass and their huge time delay caused by the hornlength....


@ Mostlydiy:


I`m aware of volvotreters horndesigns and I think they`re actually great sounding! But they are simply too long for my livingroom!! About 25inches is the deepest I wanna build my enclosures!!
As the hornlength of either 828, 816 or JBL 4560 is relativly short I was even thinking about the Klipsch Belles enclosure! It offers a reasonable hornlength of close to 1meter but just measures 20 inches depth :bouncy:
But this enclosure is infamous for being pretty loosy horndesign :o:
The general idea is great I think, with just one bend of 180 it should operate to at least 500hz.... But I think the slope of the hornpath would have to start right at the beginning! But actually the hornpath just starts increasing size after the bend.

Horn Fanatic
05-05-2014, 09:00 AM
Hey Horn Fanatic,

I really do appreciate your effort you put in these answers!! :applaud:

Did I get you right, when I say the 828 will act under their hornloading of 165hz exactly the way a simple bassreflex-enclosure would ?
Just above that frequency, when the horn starts loading, the horn will interact the function of the bassreflex-chamber due to impedance, inductance and capacitance change...!?

But this would dissent to your statement the 816 (with smaller bassreflex-chamber) actually has a better low end, so I might got you wrong...!?
What`s precisly "better" with the 816`s bass response ? Is it louder in the midbass (80-150hz) or does it reach lower frequencies ?

I understand the mentioned drivers are better suited for horns than the E-145...
Allthough I know x-max ain`t a major property for horn-applications, I thought the extended x-max of the E-145 of 7mm could be quit usefull in the 828 due to the fact it is operating in a bassreflex in the lows, not a horn...
If it`s just for me, you don`t have to trouble yourself with checking E-145 for the JBL scoops, but thanks a lot.
Im rather not interested in the rearloaded/front directradiators due to their phase-dip in the mid bass and their huge time delay caused by the hornlength....


@ Mostlydiy:


I`m aware of volvotreters horndesigns and I think they`re actually great sounding! But they are simply too long for my livingroom!! About 25inches is the deepest I wanna build my enclosures!!
As the hornlength of either 828, 816 or JBL 4560 is relativly short I was even thinking about the Klipsch Belles enclosure! It offers a reasonable hornlength of close to 1meter but just measures 20 inches depth :bouncy:
But this enclosure is infamous for being pretty loosy horndesign :o:
The general idea is great I think, with just one bend of 180 it should operate to at least 500hz.... But I think the slope of the hornpath would have to start right at the beginning! But actually the hornpath just starts increasing size after the bend.

Yes, the 828 and 816 are considered combination enclosures, and the low end comes from the vented rear chamber. But again, it's been my experience with the 816 that it will deliver better articulate bass than the A7. It would be easy enough to determine the tuning frequency of the 816 with simple filter math, but I have a full plate for the next three days. The 816 does have the smaller chamber, but it also has the long vent and plenty of area to give you solid bass. I've always has to coax the bottom end out of an A7.

The Klipsch Belle is a short horn, too short and too small a mouth area to develop a solid 40Hz wave like the K-horn. Have you ever looked into the Klipsch Jubilee? It's a dual 12" single axis compression loader, perhaps too large for your environment, but Paul himself praised it over the box that made him famous. A pair of E120's would do very nicely in that box. You could actually build single versions if you like, if you have the floor space. I think the half version would out perform the Belle.

I need to beat feet. Allow me to digest your comments to see if I can help you further.

Ciao!

NickH
05-05-2014, 02:11 PM
There a lot of good info there Horn Fanatic. I admit I've still got a lot to learn. I know the 2220 was a good driver but I never calculated the ebp. That's quite high. Of course an original pair of d130's have very good spec too I'm sure.

150's are way out of my price range. I'm very interested in what makes a good horn driver though.

I have found that bl factor can be a bit misleading when your comparing overhung and underhung drivers. But there's important spec for different types of horns. Like I know back loaded horns are easier on drivers then sealed back front loaded horns.

I don't want to jack the thread from Dr. DB. I've often considered trying the make my own cone to get a better understanding of the mechanics of it.

Thanks though. I've learned somethings I didn't know.

Nick

more10
05-05-2014, 03:13 PM
Im rather not interested in the rearloaded/front directradiators due to their phase-dip in the mid bass and their huge time delay caused by the hornlength....

A bass reflex is also a rearloaded horn. Big front chamber and very short horn :-). I would take a 4530 any day before a bass reflex. Or a TQWT or MLTL if space is limited.

For midrange a large horn (JMLC 200T (http://www.diysoundgroup.com/horns/autotech-horns/jmlc200t.html)) with a compression driver (JBL 2482, BMS 4591 (http://www.bmsspeakers.com/index.php?id=bms_4591)) will give you hair pulling vocals. You will need a small horn above this monster though.

Below the midrange, if you got the space, go for folded front loaded midbass horns. Or backloaded like 4530 or speakerplans scoop.

Dr.db
05-05-2014, 03:25 PM
I need to beat feet. Allow me to digest your comments to see if I can help you further.


No hurry, I gladly give you time :)
I just answer right away to put my thoughts down, otherwise I might forgetem....



The Klipsch Belle is a short horn, too short and too small a mouth area to develop a solid 40Hz wave like the K-horn.


I would use the Klipsch Belle solely with a adequate subwoofer!
So something around 60hz would be great, or how low does the Belle fully hornload ?




Have you ever looked into the Klipsch Jubilee? It's a dual 12" single axis compression loader, perhaps too large for your environment, but Paul himself praised it over the box that made him famous. A pair of E120's would do very nicely in that box. You could actually build single versions if you like, if you have the floor space. I think the half version would out perform the Belle.


Yes, but too big at the moment, sorry....
I believe it would outperform a Belle easily.
Seems to be close to a Hartsfield...

maxserg
05-05-2014, 06:15 PM
If you are to believe the JBL TS sheet the 2220 is way better. The only thing that the E145 has thats better is lighter cone. The 2220 has higher fs, lower q, lower LE and way highter BL. As a matter a fact the E145 doesnt look like a very good horn loading candidate at all looking at those specs. In theory that is, in practice it might be another matter.

Dr.db
I think it would be better if you built your own mid bass horns and worked out another solution for the sub 100Hz frequencies.

Maybe something like this? This guys homepage was a catalyst for my own project startup.

http://www.volvotreter.de/index.htm

/Mostly
Lots of horn loaded systems were with the k-140 E-140. The 145 is a bit different, goes lower but it still was designed for musical instruments (organ, keyboards and bass) like the 140. I"ve seen the K-140 in Martin bass bins, A-7, 4560, etc ant they were succesful. Just my 2 cents ;)

Mostlydiy
05-05-2014, 10:18 PM
Lots of horn loaded systems were with the k-140 E-140. The 145 is a bit different, goes lower but it still was designed for musical instruments (organ, keyboards and bass) like the 140. I"ve seen the K-140 in Martin bass bins, A-7, 4560, etc ant they were succesful. Just my 2 cents ;)

I wasnt talking about the D/K/E-140 but the E145. The D/K/E-140 are exelent drivers for bass horns, not so much for midbass horns because of the low Fs. A friend of mine used E140 in his martin bins and E130 in his 4560, it was a very good match.

/Mostly

NickH
05-07-2014, 02:50 PM
I know that you can get away with more in a back loaded horn then in a sealed back front loaded. Plus just because the specs aren't perfect doesn't mean it won't work.

look at me running GPA 416-8b's in a c550 back horn. Not a horn driver but they seem to be quite happy.

keep in mind that either the altec 816 or 829 are actually horn loaded. Its just got a horn put in front. At least that's how it was explained to me. I could be wrong.

I will say that horn fanatic has the gear turning in my head. I might have to try some 130a's in my horns.


Nick

maxserg
05-07-2014, 06:13 PM
I know that you can get away with more in a back loaded horn then in a sealed back front loaded. Plus just because the specs aren't perfect doesn't mean it won't work.

look at me running GPA 416-8b's in a c550 back horn. Not a horn driver but they seem to be quite happy.

keep in mind that either the altec 816 or 829 are actually horn loaded. Its just got a horn put in front. At least that's how it was explained to me. I could be wrong.

I will say that horn fanatic has the gear turning in my head. I might have to try some 130a's in my horns.


Nick

I don't know if your statement about horn loading for the 416 but maybe the new GPA 416-8b is a different animal, because the 416 was standard factory installation in the Altec A-7 ...

Scott L
05-09-2014, 02:12 PM
Keeping in line with the discussion, and hopefully not too far off topic, but, I thought the Altec 515-8G was the most suitable for horn loading (?) [But] I did the EBP calcs and I came up with a value of only 130.
Do we then double this to arrive at the mass roll-off ?
Let's say we are not concerned with ultra low bass, as the house has subs already, can a driver like the 515-8G be used in a sealed back chamber to drive a short, but adaquately sized, horn ?

maxserg
05-09-2014, 02:41 PM
515 were used in a their AX bass horns

Dr.db
06-01-2014, 07:01 AM
Just being curious.....

How would E-130 , E-140 and E-145 compare in the JBL 4560 enclosure ?


I suppose E-130 has the best midrange dynamics, E-140 best midbass punch and E-145 the best low-end roll-off...
Im going to let those run with a single subwoofer crossed at something like 50-60.... What do you guys recommend as the best match ?

Steve Schell
06-03-2014, 09:00 PM
For a while I had four 816 enclosures stuffed with 515E and 515 16-G drivers, stacked in pairs as part of my living room system. They didn't stay long as I found the presentation a bit muddy with no real low bass. Come to think of it, the results were similar with the Magnificents (825 cabs) I had owned earlier. The early Lansing Iconic two way systems with their 612 cabs were the only reflex boxes I've really liked, but then IMO the Lansing field coil woofers made the difference there. Never tried field coil woofers in the other systems.

Dr.db
07-13-2014, 05:46 AM
Scaling down the 816 enclosure to get a 12"inch frontloaded-midrange horn, which JBL drivers would be well suited for hornloading from 200-800hz...!?
I suppose the rearchamber could be sealed and wouldn`t need reflexports anymore.
Maybe E-120....

Mostlydiy
07-13-2014, 11:21 PM
E120 is a real killer as well as the 2202. Either one should rock your house

/Mostly