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View Full Version : Woofer Comparisons 2215 vs 2235



mbottz
10-17-2006, 07:57 AM
For all those more knowledgable than myself how does the 2215H compare to the 2235H? Which one has better base? Do they cross at about the same frequency? Which one is better suited for a L300 clone I am thinking about?

Thanks for the help

Mb

slxrti
10-17-2006, 10:16 AM
For all those more knowledgable than myself how does the 2215H compare to the 2235H? Which one has better base? Do they cross at about the same frequency? Which one is better suited for a L300 clone I am thinking about?

Thanks for the help

Mb
There is no comparison, the 2235 will blow the 2215 away. Deeper bass. and lower distortion in a smaller cabinet.

slxrti

Robh3606
10-17-2006, 10:16 AM
The 2235 would be the best choice for an L300 clone. The 2235 can be used higher,up to 1K than the 2215H and it goes lower as well. The recommended replacement for the 2215H, that could be crossed higher and give a similar low end response, would be the 2234. The 2234 is a 2235 without the mass ring.

Rob:)

Mr. Widget
10-17-2006, 11:03 AM
The 2235 would be the best choice for an L300 clone.Absolutely!

As has been said above, the LE15A/2215 doesn't have quite the extended deep bass as the 2235H... I personally think that both woofers shouldn't be used above 500Hz, but since JBL has done it numerous times who am I to bring up physics and sound quality...:D

The LE15A/2215 has a different sound than the 2235H and some people prefer it, that said the 2235H was designed years later and is generally considered an improvement in virtually all performance areas. The LE15A/2215 is certainly no slouch though, and the new state of the art 1500AL is much more closely related to it than the 2235H.

These plots show the added bass extension of the 2235H (green) over the LE15A/2215 and the second plot shows how the LE15A/2215 is X-max limited in the deep bass due to the suspension and probably also it's underhung design. Obviously in the early 60's the idea that digital audio with bass down to 10Hz just wasn't visible on the horizon.


Widget

Thom
10-17-2006, 01:12 PM
Please don't holler. I had recently had come under the impression that the LE15a was the same magnet structure and under hung like the E145. I guess what I've actually been seeing is LE15H. Is that the same except with the new magnet structure and under hung instead of overhung? If that is the case is a K145 overhung or underhung and I'm guessing that probably E145 kits don't belong in K145 frames? I was under the impression that when the Le15A came out 15 inch speakers either had the 11 lb assy. of the D130 or the 19 lb assy of the LE15A. I'm seriously soaking in as much info as I can. I thought I new much more than I do perhaps my information was correct at one time perhaps not. any way anybody fed up with spoonfeeding me information I can appreciate that and you obviously aren't obligated to continue but anybody with the patience to continue, I appreciate it very much. I can't explain my need to know. Thank you.

Does the 135A have any potential as a subwoofer? I've listened to a pair for a couple of years and haven't been impressed. I've had an 800 Altec horn on them, I've had an Ess HEIL tweeter on them all with the 135A's just in the flair cabinets. A couple of weeks ago I stuck some EV horns on top of them that I got from a traveling company and the whole nature of the woofer seems to have changed. Befor all I had to say about it was it was cleaner and less boomier than an L100 but now I'm impressed and wondering if a different box woud do more or if this is what they have.

Zilch
10-17-2006, 02:34 PM
http://www.linearteam.dk/default.aspx?pageid=winisd

mbottz
10-17-2006, 03:10 PM
Absolutely!

As has been said above, the LE15A/2215 doesn't have quite the extended deep bass as the 2235H... I personally think that both woofers shouldn't be used above 500Hz, but since JBL has done it numerous times who am I to bring up physics and sound quality...:D

The LE15A/2215 has a different sound than the 2235H and some people prefer it, that said the 2235H was designed years later and is generally considered an improvement in virtually all performance areas. The LE15A/2215 is certainly no slouch though, and the new state of the art 1500AL is much more closely related to it than the 2235H.

These plots show the added bass extension of the 2235H (green) over the LE15A/2215 and the second plot shows how the LE15A/2215 is X-max limited in the deep bass due to the suspension and probably also it's underhung design. Obviously in the early 60's the idea that digital audio with bass down to 10Hz just wasn't visible on the horizon.


Widget

I am looking at the graphs and they look very close to the uneducated novice such as myself. Can you help me understand what the graph for the 2235 shows that is so much better than the 2215? Please be patient as I am only trying to learn how to interpret this data. Thanks in advance for all the help.

Thanks

Mb

Mr. Widget
10-17-2006, 03:42 PM
I am looking at the graphs and they look very close to the uneducated novice such as myself. Can you help me understand what the graph for the 2235 shows that is so much better than the 2215?If you compare the response at 30Hz you'll see that the 2235 has 3dB greater output... this is not trivial. Playing music with deep bass you would hear this as a profound difference.

Looking at the max SPL graph, you'll see that the 2235 is capable of a full 6 dB greater output at 40Hz... What this means is that if you add bass boost you will hit the maximum before distortion a full six dB earlier with the LE15A. The importance of this is that if you were to take the LE15A and add EQ to get deeper bass, you can see that even adding this boost, the capabilities of the LE15A are significantly below that of the 2235H at lower frequencies. Depending on your application, room size, musical taste, SPL demands, etc.... the LE15A/2215 may be just fine... I used them for years and really liked them... I liked the 2235Hs better, and the 1500ALs better still... though for my application I did need to use bass boost with the 1500ALs.

Widget

johnaec
10-17-2006, 06:49 PM
To add to what Widget said, even if the 2215/LE15 could take the power, it would require 4 times the amount required by the 2235 to achieve the same volume at 40hz.

Edit: Actually, looking at the graphs, the amplitude response of the 2215/LE15 is only 3db down at 40hz, so it would only take twice the power of the 2235 to reach the same volume ay 40hz, but it looks like it can only handle 1/4 the power at 40hz. 'Sorry for the confusion... :o:

John

John
10-17-2006, 09:47 PM
If you can try them both and decide for yourself. I have heard both and like them both. Like widget said the 2215 is no slouch and you might like it better. but if your goal is a L300 clone I would go with a 136-2231 or 2235H

Thom
10-18-2006, 12:40 PM
[quote=Mr. Widget]If you compare the response at 30Hz you'll see that the 2235 has 3dB greater output... this is not trivial. Playing music with deep bass you would hear this as a profound difference.

Im' no expert but I've never been afraid to jump in when I was wrong befor why stop now. I have always understood that 3db was the difference needed for perceptable difference. That a difference of 1 or 2 db the human hearing could not perceive. So it took a doubling of the power for us to hear the difference. One other thing that has long bothered me is that every where but audio 6db is refered to as double. Is this because were looking at voltage and refering to power. If not then why is it?

edgewound
10-18-2006, 12:48 PM
Im' no expert but I've never been afraid to jump in when I was wrong befor why stop now. I have always understood that 3db was the difference needed for perceptable difference. That a difference of 1 or 2 db the human hearing could not perceive. So it took a doubling of the power for us to hear the difference. One other thing that has long bothered me is that every where but audio 6db is refered to as double. Is this because were looking at voltage and refering to power. If not then why is it?


Maybe you're thinking of the "Inverse Square Law"....where every doubling of distance results in 6dB drop in SPL.

To get an increase of 6dB SPL at a given distance requires four times the power. In other words 3db(double the power)+ 3dB(double the power again)= 6dB(2^2)

Mr. Widget
10-18-2006, 01:17 PM
Im' no expert but I've never been afraid to jump in when I was wrong befor why stop now. I have always understood that 3db was the difference needed for perceptable difference. That a difference of 1 or 2 db the human hearing could not perceive. So it took a doubling of the power for us to hear the difference. One other thing that has long bothered me is that every where but audio 6db is refered to as double. Is this because were looking at voltage and refering to power. If not then why is it?
Please don't take this wrong but you seem to frequently have your facts a bit scrambled. There are key words, phrases and concepts there, but perhaps you need to change your reading list.

1dB is considered the minimum threshold that an average person can hear. This is for broad band white noise, but in my experiments a change in 0.5 dB can be audible in the mid band where our hearing is most sensitive.

A 3dB increase is the same as doubling the input power and is quite audible. A 10dB increase is considered to be what we perceive as "twice as loud" and it requires ten times the input power.

In any event, a fairly broad band increase of 3dB as pictured in the simulation above would be quite audible to anyone with normal hearing if playing music with deep bass content. Realize that the increase at 40Hz is also ~3dB and 40Hz is fairly common in a wide variety of music.


One other thing that has long bothered me is that every where but audio 6db is refered to as double.
:blink:

What Edge said...


Widget

scott fitlin
10-18-2006, 01:40 PM
I say we can hear 1db,2db, even .5db differences. I can on my system

Yes, mostly in the midband, but its audible.

Using the BSS 366t and it has increments in .1db steps, and it is accurate, I can hear small changes, .5db is definitely an audible change.

Rolf
10-18-2006, 02:59 PM
This is how I have learned it: If a speaker plays 90db with 1W input you need 2W for 93db, 4W for 96db, 8W for 99db and so on.

Consider you use 100W to play a 30Hz tone at a certain level with the 2235H, then the 2215 needs 200W to do the same, and THAT is important. Consider this if the speaker only produce 86db with 1W and you want to play 110db, witch is considered the loudest passage in a Symphony orchestra.

Also remember that a 10db headroom is recommended.

How small differences it is possible to hear, I don't really know.

Thom
10-18-2006, 03:31 PM
I think I acknowleged (where's those flashbacks they promised us anyway) that I might have it wrong in the first place and was not trying to argue facts about the two woofers at all, but mostly straighten out, for myself at least, some terminology. Now that you say it, what I've always heard was that 3db was noticeably louder and either I got it mixed up or I interpeted that wrong. But time after time, not in connection with audio, I've seen 6db called double. With sound I've either always or almost always seen 3db called double. Things like that bother me. As far as how I take it. Frequently I preface things with some sort of caveat because I'm not real sure, and anyway if I'm wrong and nobody says anything I'll probably be a little more sure of the wrong answer nextime. I only threw that out there in case someone understood why and felt like explaining it.

Zilch
10-18-2006, 03:39 PM
http://audioheritage.org/vbulletin/showthread.php?t=10169

Mr. Widget
10-18-2006, 03:45 PM
But time after time, not in connection with audio, I've seen 6db called double. With sound I've either always or almost always seen 3db called double.The decibel is a measure of sound... what applications other than sound would you have seen dB in use? In Pro Audio there are dBU and dBV units, but these are to relate an audio signal which is an electrical voltage to the log scale that relates to audio.

Other than the halving and doubling of distance that is in multiples of 6dB that was mentioned by Edge, and the 6dB that is gained from adding a second identical woofer to a system, I can't think of a reference where 6dB would be a double anything???


I only threw that out there in case someone understood why and felt like explaining it.Well, I hope it makes sense now... Rolf's example is also correct and may be easier to get a handle on.


Widget

grumpy
10-18-2006, 03:47 PM
2x voltage = 6dB gain (voltage and power), but this is a 4x gain in power (recalling that
power is related to the voltage squared), and still 6dB.

so a 2x power gain is 3dB ... which is ~1.4x the voltage

clear as mud. :)

scott fitlin
10-18-2006, 03:51 PM
I think I acknowleged (where's those flashbacks they promised us anyway) that I might have it wrong in the first place and was not trying to argue facts about the two woofers at all, but mostly straighten out, for myself at least, some terminology. Now that you say it, what I've always heard was that 3db was noticeably louder and either I got it mixed up or I interpeted that wrong. But time after time, not in connection with audio, I've seen 6db called double. With sound I've either always or almost always seen 3db called double. Things like that bother me. As far as how I take it. Frequently I preface things with some sort of caveat because I'm not real sure, and anyway if I'm wrong and nobody says anything I'll probably be a little more sure of the wrong answer nextime. I only threw that out there in case someone understood why and felt like explaining it.Its not that you are wrong. They do teach us that we cant hear this or that. Sometimes we find out otherwise, though.

Take power for example! They say to achieve a 3db difference, that you must double the power, and that anything under a 3db difference will not be heard. Now, I say when I change tweeter amps from Crown D-75,s to Crown Power Line 2,s I hear a difference, big time. But, the D-75 is rated at 35wpc@8ohms -vs- the Power Line 2,s rating of 50wpc@8ohms. They say I would have to double to hear an increase in loudness, so the D-75 making 35wpc should have to increase to 70wpc to make a difference to my ears. Yet, I hear an audible increase in tweeter volume going from the D-75 to the Power Line 2 and its only a 15w difference!

With my fifteens, an audible difference in loudness can be heard with a 50w per woofer increase. Doubling would be insanely LOUD!

I know what they say, but I say different!

:D

Thom
10-18-2006, 04:07 PM
Thanks grumpy thats what I thought. Scott I'm not sure, today nothing has knobs but they used to and the difference between an audio taper pot and a liner pot are really radical. Not having done all these test or studied them I'm also not saying you're wrong. I think when you change the tonal balance that is a totally different thing.

scott fitlin
10-18-2006, 04:18 PM
Thanks grumpy thats what I thought. Scott I'm not sure, today nothing has knobs but they used to and the difference between an audio taper pot and a liner pot are really radical. Not having done all these test or studied them I'm also not saying you're wrong. I think when you change the tonal balance that is a totally different thing.I totally agree that changing tonal balance accounts for more than we think. But, I know the difference between volume and tone.

With some speakers you can hear an audible increase in level without using the textbook double the power.

Using a Crown DC-300A, and four Altec 421,s you can hook em up two woofers per channel for 255wpc@4ohms, or you can wire em up four woofers in series/parallel for 8ohms, using the amp in bridge mono, 600w rated 8ohms. You will hear a difference in level between the two ways of setup, yet is about the same amount of power! According to the specs, bridge mono provides just a hair more power, but not enough ( according to textbook ) to make an audible increase in level. But, it does make an audible difference.

grumpy
10-18-2006, 04:27 PM
"Just Noticeable Differences"

http://www.audioholics.com/techtips/roomacoustics/HumanHearingAmplitude.php

(about 1/2 way down the page)

scott fitlin
10-18-2006, 04:38 PM
Thats great reading Grumpy. And I agree with some of it, but I still maintain that I can hear .5db changes in my system. They say you can too, but at lower volumes it becomes harder to hear. Funny, I do my critical listening at lower volumes, not higher, and I hear the most minute details at the lower volumes.

Maybe I was a dog in another life, I dont know! They have great hearing.

:D

toddalin
10-18-2006, 05:02 PM
The 3 dBA difference being "just audible" relates to sound in an exterior, uncontrolled environment. Changes of less than 0.5 dB are certainley audible in a quiet, controlled environment, like sitting in a quiet living room. My Yamaha volume control is calibrated in 0.5 dBA steps and I can certainly hear as it steps up or down (and my ears aren't all that great anymore).

With respect to the changes some are hearing when only increasing available wattage by less than double the power, you may be failing to consider the sensitivity of the equipment. One amp may be rated at less watts, but may take less input voltage to produce a given level than an amp rated at more watts, but less sensitivity.

scott fitlin
10-18-2006, 05:26 PM
I am very aware of input sensitivities of different amps. Level matching is part of system setup, and usually I select certain amps for certain ranges with their respective input sensitivities taken into consideration.

However, as is the case with the DC-300A, same amp used two different ways yields different apparent loudness levels, and different shades of tonality.

Peak power is also apparently stronger, this being indicated by the much larger transient punch the amp seems to have!

Rolf
10-19-2006, 12:55 AM
... Take power for example! They say to achieve a 3db difference, that you must double the power, ...

That was exactly what I said in my previous post.