Full range speaker to 20Hz?

[Steve C 2020]

Why is it that there is no Harman products (full range speakers) that are designed to go flat to 20Hz (3db down at 20Hz anechoic)

I understand that a 3 cu ft speaker designed to go flat to 20Hz would have a low sensitivity (maybe 84 db). I also understand that JBL (Harman group) has a reputation for high sensitivity systems. And people have the option to utilize a sub woofer for low frequency extension.

With all of that said, why is it that there is no products (full range speakers) that are designed to go flat to 20Hz?

The only 2 possible answers that came to mind is:
1. There isn’t much demand for this type of product
2. It is extremely difficult to engineer

Any thoughts why it is difficult to find such a product? I am assuming that it would be attractive to at least some people.

PS: I am referring to a consumer type passive speaker (speakers with no internal amp, no DSP etc). I also realize that “in room response” of many speakers will measure down to 20Hz but I am looking for anechoic response to 20Hz.

PSS: If it would be more appropriate for me to post this in a different forum (sub group) let me know. I am a newbie :confused:

[Mr. Widget]

Welcome newbie and you picked a perfect place to post.

I recently measured some passive subs with true flat to 20Hz bass. These units are about 100 cu ft each with four 12" or 15" drivers per cabinet and are in a transmission line configuration. The speakers were built into a client's home permanently built under a pair of staircases in their Great Room. I was testing them to see if they were worth keeping... they definitely were!

I have never met another speaker that actually was flat to 20Hz without some form of EQ. I realize these speakers are not a full range system, but I mention them because it gives you an idea of what is required to produce true 20Hz response and have some level of usable output.


Also, I imagine in most cases a speaker that is truly anechoically flat (a 4 pi measurement) to 20Hz would be very bass heavy in a normal 2 pi setting.


Widget

[Steve C 2020]

Welcome newbie and you picked a perfect place to post.

I recently measured some passive subs with true flat to 20Hz bass. These units are about 100 cu ft each with four 12" or 15" drivers per cabinet and are in a transmission line configuration. The speakers were built into a client's home permanently built under a pair of staircases in their Great Room. I was testing them to see if they were worth keeping... they definitely were!

I have never met another speaker that actually was flat to 20Hz without some form of EQ. I realize these speakers are not a full range system, but I mention them because it gives you an idea of what is required to produce true 20Hz response and have some level of usable output.


Also, I imagine in most cases a speaker that is truly anechoically flat (a 4 pi measurement) to 20Hz would be very bass heavy in a normal 2 pi setting.


Widget

I am sorry because I wasn't sure if I should "Reply With Quote" or "Reply to Thread" Newbie :confused:

If you don't mind me asking, what was the estimated sensitivity of that 100 cu ft system? Did the woofers have identical crossovers or did they have low pass filters at different frequencies (helper woofers)?

[Mr. Widget]

I didn’t take any measurements that would give me an accurate sensitivity since these will be in a multi amp system, it really doesn’t matter. If I had to guess I would say probably 90dB 1watt/meter per driver. I measured all 8 woofers independently.

The existing networks were discarded as we will be using new amps with built in DSP. The woofers are wired as two identical pairs of paralleled drivers, they are all running full range and will require two amplification channels per woofer cabinet.

Due to the natural filtering of the front loaded transmission line they roll off naturally above about 200Hz.


Widget

[Steve C 2020]

Welcome newbie and you picked a perfect place to post.

I recently measured some passive subs with true flat to 20Hz bass. These units are about 100 cu ft each with four 12" or 15" drivers per cabinet and are in a transmission line configuration. The speakers were built into a client's home permanently built under a pair of staircases in their Great Room. I was testing them to see if they were worth keeping... they definitely were!

I have never met another speaker that actually was flat to 20Hz without some form of EQ. I realize these speakers are not a full range system, but I mention them because it gives you an idea of what is required to produce true 20Hz response and have some level of usable output.


Also, I imagine in most cases a speaker that is truly anechoically flat (a 4 pi measurement) to 20Hz would be very bass heavy in a normal 2 pi setting.


Widget

In regards to your comment about a system that measures flat in a 4pi environment then listening to it in 2 pi setting:

I think that it can potentially sound very nice. Obviously if the frequencies between 100Hz to 300Hz are exaggerated, they will sound very boomy. But if the frequencies between 20hz to 60hz are accentuated, it could be a desirable effect. I would maybe depend on the size and acoustics of the room. Some recording studios are mixing with monitors that measure flat down to 20Hz (4pi) like JBL M2 and PMC BB7 as an example. I have listened to systems with nice powered subs that were correctly integrated measuring flat to 20hz that sounded good. Maybe other people would not agree with me on that point but that is my experience.

[Steve C 2020]

I didn’t take any measurements that would give me an accurate sensitivity since these will be in a multi amp system, it really doesn’t matter. If I had to guess I would say probably 90dB 1watt/meter per driver. I measured all 8 woofers independently.

The existing networks were discarded as we will be using new amps with built in DSP. The woofers are wired as two identical pairs of paralleled drivers, they are all running full range and will require two amplification channels per woofer cabinet.

Due to the natural filtering of the front loaded transmission line they roll off naturally above about 200Hz.


Widget

That sounds like a very fun project. :) Were you able to get any ground plane measurements using an LMS?

[Steve C 2020]

That sounds like a very fun project. :) Were you able to get any ground plane measurements using an LMS?

Maybe if you built them in the house, it would have been impossible to get GP measurements before installing them. It is not easy to put a 100 cu ft box on a hand truck and move it around. lol. :eek:

[Mr. Widget]

Maybe if you built them in the house, it would have been impossible to get GP measurements before installing them. It is not easy to put a 100 cu ft box on a hand truck and move it around. lol. :D

Yes, I couldn’t even see the drivers, much less move the beasts. Several walls and a built in safe would have to be moved to get to them!


I have never performed a ground plane measurement. Not to discount their usefulness, but I have found close mic measurements during a system design project or spatially averaging 8-9 measurements of a finished system are easy and give me the info I need.


Widget

[HCSGuy]

Years ago, I used to sell Definitive Technology speakers, which were known for putting subwoofers into everything - tower speakers with a powered sub in the bottom, even some of their center speakers had a subwoofer. While these don’t strictly fit your definition, as they got close to 20hz only by being powered and EQ’d, they were full range towers. However, it was very rare that we got good bass and good imaging with the speakers in the same place. Telling someone who just dropped $3k on powered towers that you think they should buy an additional subwoofer it not usually appreciated, but was often the case. I think 20hz towers are rare just because 40hz towers with an additional really good subwoofer or two are usually easier to get to sound good.

[Mr. Widget]

However, it was very rare that we got good bass and good imaging with the speakers in the same place. Telling someone who just dropped $3k on powered towers that you think they should buy an additional subwoofer it not usually appreciated, but was often the case. In the 2 channel world adding subs is usually frowned upon, but yes most of us have rooms that are a real challenge.

Even in the better purpose built home theaters that I work on we have significant acoustic modeling and testing... which we use to locate subs. Typically we are also using 4 or more subs ideally located in corners or mid walls room dependent and very separate from the other speakers!


Widget

[Steve C 2020]

:D

Yes, I couldn’t even see the drivers, much less move the beasts. Several walls and a built in safe would have to be moved to get to them!


I have never performed a ground plane measurement. Not to discount their usefulness, but I have found close mic measurements during a system design project or spatially averaging 8-9 measurements of a finished system are easy and give me the info I need.


Widget

WOW! That sounds like a very complex installation. I cant imagine designing 100 cu ft TL cabinet.
I thought that a GP measurement is more accurate for determining what the speaker sounds like in the listening position (for people who don't have access to a Anechoic chamber) but maybe that is not true. I was under the impression that JBL engineers often use that method for there low frequency measurements. It also seems hard to measure the sensitivity with close miking.

[Steve C 2020]

Years ago, I used to sell Definitive Technology speakers, which were known for putting subwoofers into everything - tower speakers with a powered sub in the bottom, even some of their center speakers had a subwoofer. While these don’t strictly fit your definition, as they got close to 20hz only by being powered and EQ’d, they were full range towers. However, it was very rare that we got good bass and good imaging with the speakers in the same place. Telling someone who just dropped $3k on powered towers that you think they should buy an additional subwoofer it not usually appreciated, but was often the case. I think 20hz towers are rare just because 40hz towers with an additional really good subwoofer or two are usually easier to get to sound good.

You make a good point. sometimes it is nice to be able to locate the subs in a different spot than the full range speakers and typically use an active EQ at 80 Hz. It is more flexible and you have more control over the low frequency volume. With that said, do you think there would be any advantage to a 4 cu ft speaker (for example) that was + - 1.5db 20 - 20Khz? You wouldn't need to be concerned with things like if the phase of the sub was in sink with the FR speakers and other integration issues.

I didn't understand your comment "it was very rare that we got good bass and good imaging with the speakers in the same place" Maybe you were talking about placing the FR speakers and the subwoofer in close proximity to each other.

[Mr. Widget]

I didn't understand your comment "it was very rare that we got good bass and good imaging with the speakers in the same place"He is talking about speaker placement. When you set up the speakers for ideal imaging in the room, relative to the listening position, room boundaries, reflections etc., you may find that the low frequency room modes or nulls may not be fall where you like. If you move subs around in the room separately to the main speakers you have greater flexibility and can get the best bass and imaging.


Widget

[Mr. Widget]

WOW! That sounds like a very complex installation. I cant imagine designing 100 cu ft TL cabinet.
I thought that a GP measurement is more accurate for determining what the speaker sounds like in the listening position (for people who don't have access to a Anechoic chamber) but maybe that is not true. I was under the impression that JBL engineers often use that method for there low frequency measurements. It also seems hard to measure the sensitivity with close miking.It was a very advanced custom install system with 3' ribbons on four walls with 12" infinite baffle helper woofers mounted in the floor directly below each ribbon and the pair of massive subs.

Unfortunately I never got to hear it. The system was already in need of repair/replacement by the time our client bought the house. Luckily after testing the subs, I was able to establish that while someone had mis-wired part of it, they were still quite good.

Regarding ground plane measurements, they are a very good way to measure bass, but they must be made outdoors or in a very large room. You do not want any additional planes beyond the one you are using.

Regarding measuring sensitivity, I have never found measuring sensitivity particularly important. Relative sensitivity is usually quickly established and that is all I have ever needed to know. I guess if I was a speaker manufacturer, I would bother to measure the drive voltage and calculate the sensitivity, but I am not. :D


Widget

[Steve C 2020]

In the 2 channel world adding subs is usually frowned upon, but yes most of us have rooms that are a real challenge.

Even in the better purpose built home theaters that I work on we have significant acoustic modeling and testing... which we use to locate subs. Typically we are also using 4 or more subs ideally located in corners or mid walls room dependent and very separate from the other speakers!


Widget

Yes I think that a full range tower speaker would be more popular in the 2 channel world. I noticed that the Definitive technology DEMAND D17 is -3db 43 Hz and they have aluminum tweeters. Do you think they have the sound quality of a good HIFI tower speaker? I wonder what a nice pair of tower speakers (like Revel Salon 2 -3db at 23Hz) would sound like in a listening room running 2 channel. I am guessing that the Salon speakers have a max SPL of 105db @ 23Hz. Do you think they would sound as good as a sat / sub combo? I think that you are probably right about placing the low frequency drivers in the corner of the room but I still would like to do an A - B comparison. What do you think?

[Steve C 2020]

He is talking about speaker placement. When you set up the speakers for ideal imaging in the room, relative to the listening position, room boundaries, reflections etc., you may find that the low frequency room modes or nulls may not be fall where you like. If you move subs around in the room separately to the main speakers you have greater flexibility and can get the best bass and imaging.


Widget

Thank you for explaining. Yeah I finally figured it out lol. little slow :crying:

[Steve C 2020]

It was a very advanced custom install system with 3' ribbons on four walls with 12" infinite baffle helper woofers mounted in the floor directly below each ribbon and the pair of massive subs.

Unfortunately I never got to hear it. The system was already in need of repair/replacement by the time our client bought the house. Luckily after testing the subs, I was able to establish that while someone had mis-wired part of it, they were still quite good.

Regarding ground plane measurements, they are a very good way to measure bass, but they must be made outdoors or in a very large room. You do not want any additional planes beyond the one you are using.

Regarding measuring sensitivity, I have never found measuring sensitivity particularly important. Relative sensitivity is usually quickly established and that is all I have ever needed to know. I guess if I was a speaker manufacturer, I would bother to measure the drive voltage and calculate the sensitivity, but I am not. :D


Widget

That sounds like an interesting system with 3' ribbons etc. Sometimes I mis-wire systems also. I assume your talking about having a driver with reversed polarity. I have a small AA battery with short wires soldered to the ends for quickly checking to see that all the low frequency drivers are in phase with each other.

Yes my GP measurements are usually about 80 ft from the closest object. I will sometimes run a gated sweep above 300Hz then splice that curve into a GP curve. I live about 10 min drive from the offices of both Linear X LMS and also AP (Audio Precision). Those are companies that make / made speaker test equipment in Oregon (as you probably know).

[1audiohack]

...I live about 10 min drive from the offices of both Linear X LMS and also AP (Audio Precision). Those are companies that make / made speaker test equipment in Oregon (as you probably know).

Is there anything left of LinearX?
Barry.

[Steve C 2020]

Is there anything left of LinearX?
Barry.

Nope. I think they sold the name to a co in Germany or something.

[1audiohack]

I thought they were done but didn’t know if someone had got that ball rolling again.

Sorry for the divergence.

Thank you.
Barry.

[Steve C 2020]

I thought they were done but didn’t know if someone had got that ball rolling again.

Sorry for the divergence.

Thank you.
Barry.

I am still using my old LMS. I hope it doesn't die anytime soon.

[Robh3606]

I am running LEAP on XP so not sure how much longer it will work. This thread might help if you get into a bind!

https://www.diyaudio.com/forums/software-tools/308061-installing-linearx-leap-5-64-bit-windows-7-windows-10-a.html

Unfortunately there is no support even for the last versions which is a shame it's such great program!

Rob:)

[Steve C 2020]

Years ago, I used to sell Definitive Technology speakers, which were known for putting subwoofers into everything - tower speakers with a powered sub in the bottom, even some of their center speakers had a subwoofer. While these don’t strictly fit your definition, as they got close to 20hz only by being powered and EQ’d, they were full range towers. However, it was very rare that we got good bass and good imaging with the speakers in the same place. Telling someone who just dropped $3k on powered towers that you think they should buy an additional subwoofer it not usually appreciated, but was often the case. I think 20hz towers are rare just because 40hz towers with an additional really good subwoofer or two are usually easier to get to sound good.

I noticed you are in Bend. I grew up in Lapine when I was around 10 years old.

[tommytoa]

There's a few reasons I can think of why this isn't common;

- Flat to 20 hz anechoic means extremely bass-heavy speakers in-room. Each boundary in proximity might give up to 3 dB per octave room gain below 100 hz.

- You can have any two combination you like of extension, small cabinet and sensitivity, but you can't have them all. Hoffman's iron law. Sacrificing sensitivity is not a very good idea and flat to 20 hz means huge box.

M2 isn't flat to 20 hz, not by a long shot. Still, they require me to drop the 4,7 dB EQ boost at 21,5 hz AND to shelve down the bass by about 4 dB below 50 hz in my room to maintain a somewhat of a Harman-type in-room curve.
This is the reason it's common to design in about -3 dB oct shelving from around 100 hz - to account for real rooms.

Too much bass makes everything sound bloated and puffy, drowning all details in the music.

87784

[RMC]

What is feasible in terms of F3, cab size and efficiency has been established by R.H. Small since the seventies in Vented Box..., Part 1, p. 324 widely circulated on the Net. There is no magic unfortunately.

Small's chart below gives the details on this. Increasing pic size after saving it could make it easier to read the description under the chart (Fig. 16).

Note that according to Eargle's Loudspeaker Handbook 1% efficiency is equivalent to 92 db/1W /1M sensitivity (half space, piston band). 2% = 95 db and 5% = 99 db, with most speaker systems at around 1-2%.

Not a whole lot, but the cost of Watts is relatively low compared to the old days...

Richard

87785

[Steve C 2020]

I am running LEAP on XP so not sure how much longer it will work. This thread might help if you get into a bind!

https://www.diyaudio.com/forums/software-tools/308061-installing-linearx-leap-5-64-bit-windows-7-windows-10-a.html

Unfortunately there is no support even for the last versions which is a shame it's such great program!

Rob:)
Was LEAP made by LinearX or different company?

[Steve C 2020]

What is feasible in terms of F3, cab size and efficiency has been established by R.H. Small since the seventies in Vented Box..., Part 1, p. 324 widely circulated on the Net. There is no magic unfortunately.

Small's chart below gives the details on this. Increasing pic size after saving it could make it easier to read the description under the chart (Fig. 16).

Note that according to Eargle's Loudspeaker Handbook 1% efficiency is equivalent to 92 db/1W /1M sensitivity (half space, piston band). 2% = 95 db and 5% = 99 db, with most speaker systems at around 1-2%.

Not a whole lot, but the cost of Watts is relatively low compared to the old days...

Richard

87785

Yes that is absolutely true. Have you designed any passive full range systems with extended bass?

[Steve C 2020]

There's a few reasons I can think of why this isn't common;

- Flat to 20 hz anechoic means extremely bass-heavy speakers in-room. Each boundary in proximity might give up to 3 dB per octave room gain below 100 hz.

- You can have any two combination you like of extension, small cabinet and sensitivity, but you can't have them all. Hoffman's iron law. Sacrificing sensitivity is not a very good idea and flat to 20 hz means huge box.

M2 isn't flat to 20 hz, not by a long shot. Still, they require me to drop the 4,7 dB EQ boost at 21,5 hz AND to shelve down the bass by about 4 dB below 50 hz in my room to maintain a somewhat of a Harman-type in-room curve.
This is the reason it's common to design in about -3 dB oct shelving from around 100 hz - to account for real rooms.

Too much bass makes everything sound bloated and puffy, drowning all details in the music.

87784

That makes sense

[Steve C 2020]

I am running LEAP on XP so not sure how much longer it will work. This thread might help if you get into a bind!

https://www.diyaudio.com/forums/software-tools/308061-installing-linearx-leap-5-64-bit-windows-7-windows-10-a.html

Unfortunately there is no support even for the last versions which is a shame it's such great program!

Rob:)

Thanks. I am running my LMS on an old windows 98 machine :crying:

[Steve C 2020]

There's a few reasons I can think of why this isn't common;

- Flat to 20 hz anechoic means extremely bass-heavy speakers in-room. Each boundary in proximity might give up to 3 dB per octave room gain below 100 hz.

- You can have any two combination you like of extension, small cabinet and sensitivity, but you can't have them all. Hoffman's iron law. Sacrificing sensitivity is not a very good idea and flat to 20 hz means huge box.

M2 isn't flat to 20 hz, not by a long shot. Still, they require me to drop the 4,7 dB EQ boost at 21,5 hz AND to shelve down the bass by about 4 dB below 50 hz in my room to maintain a somewhat of a Harman-type in-room curve.
This is the reason it's common to design in about -3 dB oct shelving from around 100 hz - to account for real rooms.

Too much bass makes everything sound bloated and puffy, drowning all details in the music.

87784
Although I have a friend who has passive speakers that are relatively flat down to 20Hz (anechoic) and they sounded well balanced in his listening room. Maybe it is hard to generalize because each room is so different acoustically. Possibly other people can give there opinion. Maybe I am in the minority on this one.

[1audiohack]

Was LEAP made by LinearX or different company?

LinearX.

Mine runs fine on 32 bit Win7 last I used it.

Barry.

[Robh3606]

Hello Steve

I built a pair of sort of M2's. They are passive using 2216Nd and 476Mg on the M2 waveguide. I have the 2216Nds in 4.7Cu Ft. low tuned to 26Hz. That gives them an F3 @ 47Hz and the typical banana curve. To extend the F3 they were designed to use a Q2 6Db bump filter that extends the F3 to 25Hz. That is the typical bump filter and tuning JBL has used in the BX-63/63A for the B380,B460 and on the 2242 in a cinema box.

I can adjust the notch filter from 0 to +6 in 1Db increment's. I have 2 switchable settings I can switch out 1@ +6 and one @ +4 I typically use the +6Db setting. I get pressurization all the way down to 20Hz where the sweep ends.

Even though you would think you would have issues with the F3 @ 25Hz it simply not a problem in my room.

Put on some Sinatra or 60's vintage and for the most part F3 @ 47Hz works just fine. However put on some modern Indie or something that actually has content down there and the bump filter really helps fill in and solidify the foundation of the music.

Rob:)

[Robh3606]

Mine runs fine on 32 bit Win7 last I used it.

Barry

Hello Barry

Do you have a Windows 7 drivers to install the Key Dongle??

Rob :)

[Steve C 2020]

Hello Steve

I built a pair of sort of M2's. They are passive using 2216Nd and 476Mg on the M2 waveguide. I have the 2216Nds in 4.7Cu Ft. low tuned to 26Hz. That gives them an F3 @ 47Hz and the typical banana curve. To extend the F3 they were designed to use a Q2 6Db bump filter that extends the F3 to 25Hz. That is the typical bump filter and tuning JBL has used in the BX-63/63A for the B380,B460 and on the 2242 in a cinema box.

I can adjust the notch filter from 0 to +6 in 1Db increment's. I have 2 switchable settings I can switch out 1@ +6 and one @ +4 I typically use the +6Db setting. I get pressurization all the way down to 20Hz where the sweep ends.

Even though you would think you would have issues with the F3 @ 25Hz it simply not a problem in my room.

Put on some Sinatra or 60's vintage and for the most part F3 @ 47Hz works just fine. However put on some modern Indie or something that actually has content down there and the bump filter really helps fill in and solidify the foundation of the music.

Rob:)

Nice !! The 2216Nd and the 1500AL-1 are definitely some of my favorite woofers. The 2216Nd in 14 cu ft tuned to 23Hz it will model -3db @ 23Hz But I know that is not taking into account BD (baffle diffraction). With a small amount of weight added to the cone it will model + - 0.5db 20Hz to 1Khz at 93db sensitivity. It is such a beautiful curve to look at (for me). :crying:

[1audiohack]

Hello Barry

Do you have a Windows 7 drivers to install the Key Dongle??

Rob :)
Hi Rob!

Before I tell a lie and say yes, I had better slide the old hard drive back in and make sure that my memory isn’t lying to me. Will do it tonight.

Barry.

[Steve C 2020]

Hello Steve

I built a pair of sort of M2's. They are passive using 2216Nd and 476Mg on the M2 waveguide. I have the 2216Nds in 4.7Cu Ft. low tuned to 26Hz. That gives them an F3 @ 47Hz and the typical banana curve. To extend the F3 they were designed to use a Q2 6Db bump filter that extends the F3 to 25Hz. That is the typical bump filter and tuning JBL has used in the BX-63/63A for the B380,B460 and on the 2242 in a cinema box.

I can adjust the notch filter from 0 to +6 in 1Db increment's. I have 2 switchable settings I can switch out 1@ +6 and one @ +4 I typically use the +6Db setting. I get pressurization all the way down to 20Hz where the sweep ends.

Even though you would think you would have issues with the F3 @ 25Hz it simply not a problem in my room.

Put on some Sinatra or 60's vintage and for the most part F3 @ 47Hz works just fine. However put on some modern Indie or something that actually has content down there and the bump filter really helps fill in and solidify the foundation of the music.

Rob:)
Are you using a passive crossover or active crossover in a biamped setup?

[Robh3606]

Hello Steve

It's passive design not biamp like the M2 Crossover is @ 700Hz Really enjoy them! Awesome drivers!

Rob:)

[Robh3606]

Thank Barry!

Rob:)

[Steve C 2020]

Hello Steve

It's passive design not biamp like the M2 Crossover is @ 700Hz Really enjoy them! Awesome drivers!

Rob:)
Do you think that the 476 sounds as good as the Beryllium drivers used in the Everest DD67000?

[Steve C 2020]

Hello Steve

It's passive design not biamp like the M2 Crossover is @ 700Hz Really enjoy them! Awesome drivers!

Rob:)
Very Nice !!
I don't know why I appreciate passive systems more than active (biamped) systems even though the active systems could arguably sound better. Maybe I am attracted to the simplicity of it.

[Steve C 2020]

Hello Steve

I built a pair of sort of M2's. They are passive using 2216Nd and 476Mg on the M2 waveguide. I have the 2216Nds in 4.7Cu Ft. low tuned to 26Hz. That gives them an F3 @ 47Hz and the typical banana curve. To extend the F3 they were designed to use a Q2 6Db bump filter that extends the F3 to 25Hz. That is the typical bump filter and tuning JBL has used in the BX-63/63A for the B380,B460 and on the 2242 in a cinema box.

I can adjust the notch filter from 0 to +6 in 1Db increment's. I have 2 switchable settings I can switch out 1@ +6 and one @ +4 I typically use the +6Db setting. I get pressurization all the way down to 20Hz where the sweep ends.

Even though you would think you would have issues with the F3 @ 25Hz it simply not a problem in my room.

Put on some Sinatra or 60's vintage and for the most part F3 @ 47Hz works just fine. However put on some modern Indie or something that actually has content down there and the bump filter really helps fill in and solidify the foundation of the music.

Rob:)
Is the 6Db bump filter an active filter? It sounds like an an active EQ to extend the low freq response of the system. I apologize because I don't remember well the design of the BX-63/63A. I became familiar with JBL products around 1990 but mostly sound reinforcement products at that time.

[1audiohack]

Thank Barry!

Rob:)

Damn I lied. This hard drive is on XP. :(

So sorry!

Barry.

[RMC]

Hi Steve,

RE "Have you designed any passive full range systems with extended bass?" (post # 27)

I design my own boxes and have never cloned other people's or manufacturer's design.

I do mostly bass cabs with satellite systems, biamped, as i find these way more flexible and space efficient being one on top of others. Have different pairs of bass cabs and can put 2 various size satellites on top of each bass cab, so a number of satellites can be readily available, plus have more in stock to put in the speaker rotation.

The "foundation" (i.e. bass cabs) remains stable (though bought other woofers recently and have another pair in sight), while the satellites used may vary a lot. Quite easy to switch smaller boxes, and the use of banana plugs. Considering the bandwidths involved, say few hundred hertz or so on the active xo, there's way more spectrum covered by the satellites than on the bass cabs, and i think that globally it makes a larger difference sound wise when switching between tops vs bottoms.

Note that i mentioned bass cabs, not subwoofers. Proper subwoofing is too penalizing for me size wise with the space i have. Plus i don't need 20hz bass, nor rattling the neighborhood, to be happy in life. I get along pretty well with 40 or 45 hz bass which allows more reasonable LF box sizes.

Having hi-fi type speakers as well as some sound reinforcement boxes, that suits me fine as i like to try different things and various LF/MF-HF combinations, which LF cabs/satellites biamping permits almost endlessly. Regards,

Richard

[Steve C 2020]

Hi Steve,

RE "Have you designed any passive full range systems with extended bass?" (post # 27)

I design my own boxes and have never cloned other people's or manufacturer's design.

I do mostly bass cabs with satellite systems, biamped, as i find these way more flexible and space efficient being one on top of others. Have different pairs of bass cabs and can put 2 various size satellites on top of each bass cab, so a number of satellites can be readily available, plus have more in stock to put in the speaker rotation.

The "foundation" (i.e. bass cabs) remains stable (though bought other woofers recently and have another pair in sight), while the satellites used may vary a lot. Quite easy to switch smaller boxes, and the use of banana plugs. Considering the bandwidths involved, say few hundred hertz or so on the active xo, there's way more spectrum covered by the satellites than on the bass cabs, and i think that globally it makes a larger difference sound wise when switching between tops vs bottoms.

Note that i mentioned bass cabs, not subwoofers. Proper subwoofing is too penalizing for me size wise with the space i have. Plus i don't need 20hz bass, nor rattling the neighborhood, to be happy in life. I get along pretty well with 40 or 45 hz bass which allows more reasonable LF box sizes.

Having hi-fi type speakers as well as some sound reinforcement boxes, that suits me fine as i like to try different things and various LF/MF-HF combinations, which LF cabs/satellites biamping permits almost endlessly. Regards,

Richard
It is interesting because I have been an audio enthusiast for many years but just recently joined a couple of audio related forums. It is nice to talk to other people with similar interests.

Yes I agree with your concept of what I call MES (multi enclosure system). When you build a speaker system (or prototype) with drivers in different boxes then you have more flexibility and also by moving the satellite speaker forward or backward you can time-align them. I think the time aligning is more common between the tweeter and midrange so my next project I will put them in separate boxes.

It sounds like in your systems; the satellite is acting like the tweeter and mid. And the LF (low frequency) cabinet is acting like the woofer (not subwoofer). It sounds like you have the crossover at around 200Hz.

If you don't mind me asking, what size midrange / mid-bass driver do you typically use in your satellites? Do you use mostly tweeters or horns in your satellites?

Steve

[RMC]

Hi Steve,

No horns, except for some horn tweeters on the sound reinforcement boxes

XO frequency to the satellites typically around 250-300hz

Satellite boxes often house a 5 1/4" plus a dome tweeter for hi-fi cabs, and a 6" plus a dome in a horn tweeter for sound reinforcement satellites

But there are exceptions to the above, since i have some larger satellite boxes, like an SR pair having a 10" with a special cone and a dome in a horn tweeter, with the latter being able to be crossed over as low as 1500hz with a steep slope since it has an Fs of 750hz (pretty low for a 1" dome). Regards,

Richard

[Steve C 2020]

Hi Steve,

No horns, except for some horn tweeters on the sound reinforcement boxes

XO frequency to the satellites typically around 250-300hz

Satellite boxes often house a 5 1/4" plus a dome tweeter for hi-fi cabs, and a 6" plus a dome in a horn tweeter for sound reinforcement satellites

But there are exceptions to the above, since i have some larger satellite boxes, like an SR pair having a 10" with a special cone and a dome in a horn tweeter, with the latter being able to be crossed over as low as 1500hz with a steep slope since it has an Fs of 750hz (pretty low for a 1" dome). Regards,

Richard
Hi Richard,
That sounds like a solid design. I also am generally using 1” soft dome tweeters (direct radiating). The maximum size mid-range that I use is 6.5”. It seems to sound best if the mid-range is capable of generating frequencies that extend 1 octave beyond (past) X-O frequency (for all drivers). Some companies use plastic cone mid-range / mid-bass drivers but to me they don’t sound articulated (lacking in upper mid-range transients). Maybe other people don’t agree but that is my personal experience. I use traditional paper pulp mids.

My audio passion recently is designing full range towers that measure (relatively flat) from 20Hz to 20Khz. Most people don’t see the need to go below 40Hz but when I listened to speakers that extended approximately to 20Hz, I realized that it is an experience that I appreciate.

[grumpy]

All this talk reminds me of these systems from the 80's... No recollection of how they were measured.

https://www.stereophile.com/floorloudspeakers/486vmps/index.html

https://www.highendnews.info/reviews/DuntechSovereign-eng.htm

[Steve C 2020]

All this talk reminds me of these systems from the 80's... No recollection of how they were measured.

https://www.stereophile.com/floorloudspeakers/486vmps/index.html

https://www.highendnews.info/reviews/DuntechSovereign-eng.htm

It looks like the VMPS has some similarities with a line array. On that one the specs are not at all specific.

On the Duntech the specs seem relatively clear but maybe you are referring to the fact that they don’t indicate whether the measurements are in-room or anechoic / GP (ground plane). In that sense I agree. It is always best to look at a response curve that includes notations indicating the measurement details.
Steve

[HCSGuy]

All this talk reminds me of these systems from the 80's... No recollection of how they were measured.

https://www.stereophile.com/floorloudspeakers/486vmps/index.html

https://www.highendnews.info/reviews/DuntechSovereign-eng.htm

When I was in college (late 80's), I called VMPS and ended up talking to the designer (don't remember his name) and asking him questions about their Tower II, which I think you could buy as a kit. At the time, I was pretty ignorant about speaker design, but had been reading JBL catalogs my entire life. When he told me the woofers had (I think) 2" voice coils and 40oz magnets, I'm pretty sure I chortled and said something that made the discussion proceed downhill rapidly. I remember him saying something about there being many different factors to consider in getting good bass, that I should make some effort to learn speaker design, and have a nice day.

Not surprisingly, I did not buy VMPS speakers. I bought a pair of L100T3's instead.

[RMC]

Steve,

RE "Some companies use plastic cone mid-range/mid-bass drivers but to me they don’t sound articulated (lacking in upper mid-range transients)."

Most of the woofers on-hand are paper pulp cone, though some may have been treated by the manufacturer.

The 10" with special cone i use in the SR pair mentioned doesn't use a plastic cone, but rather the following (from tech sheet):

"The specially formulated cone pulp allows this driver to give a warm and smooth response throughout the bass frequency range and delivers well balanced tonal characteristics..." "Specially formulated cone coating provides HF vocal clarity." The HF vocal clarity mentioned is more low mid than HF since the driver's response extends to almost 2khz then cone breakup peak kicks in. And its not a musical instrument driver, its described as a bass driver.

A small pair of near field speakers i use is described as having "Plasiflex" cones, maybe some type of plastic??

Richard

[Steve C 2020]

Steve,

RE "Some companies use plastic cone mid-range/mid-bass drivers but to me they don’t sound articulated (lacking in upper mid-range transients)."

Most of the woofers on-hand are paper pulp cone, though some may have been treated by the manufacturer.

The 10" with special cone i use in the SR pair mentioned doesn't use a plastic cone, but rather the following (from tech sheet):

"The specially formulated cone pulp allows this driver to give a warm and smooth response throughout the bass frequency range and delivers well balanced tonal characteristics..." "Specially formulated cone coating provides HF vocal clarity." The HF vocal clarity mentioned is more low mid than HF since the driver's response extends to almost 2khz then cone breakup peak kicks in. And its not a musical instrument driver, its described as a bass driver.

A small pair of near field speakers i use is described as having "Plasiflex" cones, maybe some type of plastic??

Richard
Richard,
That is interesting. Does the "Plasiflex" cone basically look like plastic? I am assuming that it is the near field speakers are using the 5" that you mentioned before. In my experience, if the crossover point is low enough (around 2Khz) then they can sound nice but then the max SPL is limited because the excursion ability of the tweeter is limited. Maybe there are some plastic cone drivers out there that sound nice playing all the way up to 3Khz (where they are typically crossed over) but in my personal experience, have just not seen one.

The beautiful thing about speakers (and audio equip) is that we have the freedom to build the system that sounds best to us. With that said, It is always fun for me to listen to other peoples opinion. I always learn something:)

[Steve C 2020]

Steve,

RE "Some companies use plastic cone mid-range/mid-bass drivers but to me they don’t sound articulated (lacking in upper mid-range transients)."

Most of the woofers on-hand are paper pulp cone, though some may have been treated by the manufacturer.

The 10" with special cone i use in the SR pair mentioned doesn't use a plastic cone, but rather the following (from tech sheet):

"The specially formulated cone pulp allows this driver to give a warm and smooth response throughout the bass frequency range and delivers well balanced tonal characteristics..." "Specially formulated cone coating provides HF vocal clarity." The HF vocal clarity mentioned is more low mid than HF since the driver's response extends to almost 2khz then cone breakup peak kicks in. And its not a musical instrument driver, its described as a bass driver.

A small pair of near field speakers i use is described as having "Plasiflex" cones, maybe some type of plastic??

Richard

This is off topic but do you have TS data for the 2205H? The data sheet that I saw for it didn't seem to have complete TS data.

[Ed Kreamer]

Hi Steve,

You might find interesting, Drews Clues in the perspectives of the JBL library. Drew Daniels, AKA the ancient audiophile. built a whiz bang holy mackrel system out of JBL components. Also some time ago, there was a fellow who built a pair of super subwoofrs using 2 2235's per vented box. They would go down to 15 Hz or so. Each box was 17 ft3. He published his design in Audio Magazine be for it closed its doors. I'm sorry I don't remember the authors name, or the issue of Audio.

I have experimented in my own small listening space, which is also the living room of our abode, running stereo and mono signals to my own Sub type speakers. I get more bass from mono than stereo. I also crossover at 60 hz. I realize each room is different and It might vary from each recording. FYII, am a classical music listener.

Keep on Listening and have fun

Ed

[Robh3606]

Hello Ed

Don't think this is the same article but just want drop it in here as a reference as it's a bit buried in the site!


http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm


Rob:)

[Steve C 2020]

Hi Steve,

You might find interesting, Drews Clues in the perspectives of the JBL library. Drew Daniels, AKA the ancient audiophile. built a whiz bang holy mackrel system out of JBL components. Also some time ago, there was a fellow who built a pair of super subwoofrs using 2 2235's per vented box. They would go down to 15 Hz or so. Each box was 17 ft3. He published his design in Audio Magazine be for it closed its doors. I'm sorry I don't remember the authors name, or the issue of Audio.

I have experimented in my own small listening space, which is also the living room of our abode, running stereo and mono signals to my own Sub type speakers. I get more bass from mono than stereo. I also crossover at 60 hz. I realize each room is different and It might vary from each recording. FYII, am a classical music listener.

Keep on Listening and have fun

Ed
Nice !! I have TS data for the 2235. Is it similar to the 2205?

[Steve C 2020]

Hello Ed

Don't think this is the same article but just want drop it in here as a reference as it's a bit buried in the site!


http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm


Rob:)
Nice article !!

Actually I don't have anything against Powered subs and a DSP / EQ. It is just that recently I am working on passive speaker projects. My goal is +/- 1.5db 20Hz to 20Khz. Because it is more difficult to engineer, I like the challenge. From an educational standpoint, I learn more (I hope).

[Steve C 2020]

Hi Steve,

You might find interesting, Drews Clues in the perspectives of the JBL library. Drew Daniels, AKA the ancient audiophile. built a whiz bang holy mackrel system out of JBL components. Also some time ago, there was a fellow who built a pair of super subwoofrs using 2 2235's per vented box. They would go down to 15 Hz or so. Each box was 17 ft3. He published his design in Audio Magazine be for it closed its doors. I'm sorry I don't remember the authors name, or the issue of Audio.

I have experimented in my own small listening space, which is also the living room of our abode, running stereo and mono signals to my own Sub type speakers. I get more bass from mono than stereo. I also crossover at 60 hz. I realize each room is different and It might vary from each recording. FYII, am a classical music listener.

Keep on Listening and have fun

Ed
Yes I think many people blend the L & R low freq together (mono). Do you have a pair of FR (full range) speakers sitting on top of Base cabs?

[RMC]

Steve,

RE Does the "Plasiflex" cone basically look like plastic? (post #51)

Hard to say if its plastic or a coating applied to the woofer for damping/rigidity? Its relatively stiff cone though.

The XO from woofer to 19 mm tweeter is at 4.5 khz. The fun with these small near field is that they're optimized for flat power response (off axis) instead of the usual on-axis. Mfr even says not to toe them in but rather let them fire straight out. The effect is quite interesting from such small size.

Richard

87820

[RMC]

Steve,

RE This is off topic but do you have TS data for the 2205H? (post #52)

First pic is a copy, with TS parameters, of a 2205 computer printout given to me in 1980 by JBL's Canadian distributor. I don't use the driver in the 5.5 CF box indicated since its too large for this older SR woofer (not intended for subwoofer use). This old one uses imperial measures.

Second pic is the TS for 2205H from JBL's own TS Table. That one gives Metric measures.

The main discrepancy between the two sets of TS is on Xmax when converted to the same units.

Richard

8782187822

[clwinbe]

Nice article !!

Actually I don't have anything against Powered subs and a DSP / EQ. It is just that recently I am working on passive speaker projects. My goal is +/- 1.5db 20Hz to 20Khz. Because it is more difficult to engineer, I like the challenge. From an educational standpoint, I learn more (I hope).


I’ve read a review of the L100T (seemed very detailed) that stated it was remarkably flat 20Hz-20KHz +-3.5db. Your space has more to do with low end, but it was an interesting review.

[Steve C 2020]

Steve,

RE This is off topic but do you have TS data for the 2205H? (post #52)

First pic is a copy, with TS parameters, of a 2205 computer printout given to me in 1980 by JBL's Canadian distributor. I don't use the driver in the 5.5 CF box indicated since its too large for this older SR woofer (not intended for subwoofer use). This old one uses imperial measures.

Second pic is the TS for 2205H from JBL's own TS Table. That one gives Metric measures.

The main discrepancy between the two sets of TS is on Xmax when converted to the same units.

Richard

8782187822

Richard,
When I saw your 2 images it reminded me that I have a similar one from Harmon but mine is a PDF from 2008. I could have found the TS data in my copy so I apologize for forgetting that I had that. I am always happy to expand the number of drivers that I have loaded into my design software. It helps me in the design efforts of future projects.

[Steve C 2020]

Steve,

RE Does the "Plasiflex" cone basically look like plastic? (post #51)

Hard to say if its plastic or a coating applied to the woofer for damping/rigidity? Its relatively stiff cone though.

The XO from woofer to 19 mm tweeter is at 4.5 khz. The fun with these small near field is that they're optimized for flat power response (off axis) instead of the usual on-axis. Mfr even says not to toe them in but rather let them fire straight out. The effect is quite interesting from such small size.

Richard

87820
Hi Richard,
Yes that woofer cone looks very unique. I don't believe I have seen that style before. I like the 5" 2 way designs because when used together with a 12" (or 15") woofer it becomes similar to a 3 way system. A lot of 3 ways use 5" midranges.

[Steve C 2020]

I’ve read a review of the L100T (seemed very detailed) that stated it was remarkably flat 20Hz-20KHz +-3.5db. Your space has more to do with low end, but it was an interesting review.

Yes I saw maybe a similar review on the L100T. I did not see a response curve (anechoic) on that but it is probably - 10db at 20Hz. I built a speaker last summer that achieved my design goals but it was 8 cu ft. My next goal is to accomplish it in a 3 cu ft box with lower sensitivity.

[Ed Kreamer]

Steve,
you asked if I a full range speaker sitting on top of my Vlf. Yes. My main speakers are 4410's

Ed

[Robh3606]

My goal is +/- 1.5db 20Hz to 20Khz. Because it is more difficult to engineer, I like the challenge. From an educational standpoint, I learn more (I hope).

Hello Steve

Hope you can measure outside. Above 1K in-room not a issue but trying to get down below 500Hz get's really difficult because if you gate you loose resolution. When I go low I don't gate but you see the room as well so it's a crap shoot. Bottom line though is if you can get repeatability even with the room you can at least get a handle on things.

Rob:)

[Steve C 2020]

Hello Steve

Hope you can measure outside. Above 1K in-room not a issue but trying to get down below 500Hz get's really difficult because if you gate you loose resolution. When I go low I don't gate but you see the room as well so it's a crap shoot. Bottom line though is if you can get repeatability even with the room you can at least get a handle on things.

Rob:)
Hi Rob,
Thank you for that suggestion. Don't forget that I live in western Oregon where it rains everyday in the winter time LOL. Yes I understand the limitations of the gated measurements. Typically my indoor measurements are just above 1 Khz for measuring tweeter response or adjusting the X-O between the mid and tweeter. I am using a Linear X LMS for all my measurements. Anything below 1Khz I go outside at least 60 ft away from any buildings etc and take GP (ground plane) measurements.

I would be happy to post some curves but I am having trouble posting images on this forum. I don’t have any problem on other forums but for some reason this one seems different. I am just a newbie :confused:. I followed the instructions in FAQ section “attachments and images” but still having issues. I will try again.

[Steve C 2020]

Hi Rob,
Thank you for that suggestion. Don't forget that I live in western Oregon where it rains everyday in the winter time LOL. Yes I understand the limitations of the gated measurements. Typically my indoor measurements are just above 1 Khz for measuring tweeter response or adjusting the X-O between the mid and tweeter. I am using a Linear X LMS for all my measurements. Anything below 1Khz I go outside at least 60 ft away from any buildings etc and take GP (ground plane) measurements.

I would be happy to post some curves but I am having trouble posting images on this forum. I don’t have any problem on other forums but for some reason this one seems different. I am just a newbie :confused:. I followed the instructions in FAQ section “attachments and images” but still having issues. I will try again.


87841

This is GP measurement at 2m. My problem is that I want to create a speaker with similar curve in a smaller box (hopefully 3 cu ft). The speaker shown in the measurement is 9 cu ft. My target sensitivity for the smaller speaker is 84db.

[Steve C 2020]

Steve,
you asked if I a full range speaker sitting on top of my Vlf. Yes. My main speakers are 4410's

Ed
Hi Ed,
It sound like you have a solid 4 way system. The 10" woofers in the 4410s can easily go down to 60Hz and your larger woofer / subwoofer can probably go much lower. That must make a nice balance. Maybe my thinking is similar to yours because I never understood the need for a monitor to have a big 12" or 15" woofer if we are going to use a sub. It never made sense to me. :)
Steve

[Ed Kreamer]

I can think of a couple reasons.How big is the room? How loud do you want to play? Also consider that a 15 " speaker has about 130 square inches of radiating area, vs. 50 for a 10. So a 15 only has to move about 1/3 the distance to make the same amount of sound. Most likely then lower distortion. Over simplification maybe but you catch my drift.
There is also this, a bigger speaker (for the most part) simply sounds better.

For me in the size of room I have (13x16x8), a 10 works very well even for a full orchestral tutti. But for full organ pedals or depth charge explosions, a couple of vintage 15's work quite nicely. Oh yes I also run the low bass units in mono.
I actually get better low bass doing so.

As an addendum;I'm sure you know this but in the days of the LP record, the bass under 100 Hz was mixed in mono. It saved a lot of space on the disc, and could produce more bass. I wonder if the newer vinyl discs are done this way?

Ed

[Steve C 2020]

I can think of a couple reasons.How big is the room? How loud do you want to play? Also consider that a 15 " speaker has about 130 square inches of radiating area, vs. 50 for a 10. So a 15 only has to move about 1/3 the distance to make the same amount of sound. Most likely then lower distortion. Over simplification maybe but you catch my drift.
There is also this, a bigger speaker (for the most part) simply sounds better.

For me in the size of room I have (13x16x8), a 10 works very well even for a full orchestral tutti. But for full organ pedals or depth charge explosions, a couple of vintage 15's work quite nicely. Oh yes I also run the low bass units in mono.
I actually get better low bass doing so.

As an addendum;I'm sure you know this but in the days of the LP record, the bass under 100 Hz was mixed in mono. It saved a lot of space on the disc, and could produce more bass. I wonder if the newer vinyl discs are done this way?

Ed
That is interesting. I didn't know that about the mono bass on the records. I grew up in the 60s so I am familiar with them. I also own an old McIntosh tube amp. I enjoy all of it.