Horn Speakers - Is it me or.......

[dped90]

Also, the L-pad significantly reduces hiss and noise. For the lowest noise amps (Benchmark, Hypex, PuriFi, to name a few), this isn't an issue. I compared some low-noise amps to some higher noise models, since noise is an audible, and passive components like L-pads and capacitors can make a fairly significant and audible difference in a quiet room, which might be why JBL uses them in the M2 and other active models

Thanks for this as the M2 waveguide https://reconingspeakers.com/product/jbl-m2-horn-lens-5025594/ may be my choice if integrates very well with my midwoofer.

Altec 416-8B in 100L Sealed

In this blog post I test the Altec 416-8B in a 100L sealed enclosure. Testing was done outdoors for the frequency response and then brought indoors for the distortion testing. The woofers are new from Great Planes Audio. A customer has sent me the finished cabinets with drivers to integrate...

josephcrowe.com

But since it's a coaxial driver an the driver/waveguide combo will require EQ, would I run into difficulties using all passive filters rather than active DSP crossovers?

Also, depending on the design of the M2 waveguide, would it be a mistake to use it with some other kind of 1.5” throat driver, such as https://reconingspeakers.com/product/jbl-2435hpl-driver-125-30001-00x/ ?

If not, could I expect better subjective and/or measured performance from this beryllium driver with the M2?

 

[dped90]

I think the M2's waveguide would integrate better with your Altec woofers.

With my listening goals and from the polar charts of the M2 cited in my last post, would the M2 give me the kind of vertical coverage I'm looking for?

 

[Newman]

The discussion was about use of an L-pad on a compression driver. Not on a woofer. Not on a whole speaker.

My mistake, I thought he was including his 98 dB/W/m cones. Apparently full power through them is not concerning!

 

[Duke]

With my listening goals and from the polar charts of the M2 cited in my last post, would the M2 give me the kind of vertical coverage I'm looking for?

I'm not sure. (Apologies in advance - this post gets down in the weeds a bit.)

On-axis, YES. But off-axis to either side, if your ears are well above the centerline of the waveguide, I don't know, and I don't think so.

You see those little "knuckles" way down in the waveguide's throat? I think they are diffractive features which have the effect of widening the radiation pattern at high frequencies. A 1.5" throat compression driver will not inherently have the wide pattern at high frequencies that we see in the M2's horizontal and vertical off-axis measurements. Not even close!

Here's the potential issue: The knuckles are not in play along the diagonal dimensions of the waveguide. Along the diagonals, the waveguide's shape is very different from its shape exactly in the horizontal plane, and also very different from its shape exactly in the vertical plane.

Using a clock face as a reference, as you look into the throat, the two knuckles in the horizontal plane are at 9:00 and 3:00, and the two knuckles in the vertical plane are at 12:00 and 6:00. But in between the knuckles, like from 1:00 to 2:00, there are NO such diffractive features. So if you are off-axis somewhat to one side, and standing up, depending on the exact angles, I think you MIGHT be getting less high frequency energy in the direct sound.

I welcome input and/or correction from anyone who knows what the response of the M2 looks like along the waveguide's diagonals. But I would be very surprised if it's the same as the response at angles where the knuckles are fully in play.

 

[MAB]

Thanks for this as the M2 waveguide https://reconingspeakers.com/product/jbl-m2-horn-lens-5025594/ may be my choice if integrates very well with my midwoofer.

Altec 416-8B in 100L Sealed

In this blog post I test the Altec 416-8B in a 100L sealed enclosure. Testing was done outdoors for the frequency response and then brought indoors for the distortion testing. The woofers are new from Great Planes Audio. A customer has sent me the finished cabinets with drivers to integrate...

josephcrowe.com

But since it's a coaxial driver an the driver/waveguide combo will require EQ, would I run into difficulties using all passive filters rather than active DSP crossovers?

Also, depending on the design of the M2 waveguide, would it be a mistake to use it with some other kind of 1.5” throat driver, such as https://reconingspeakers.com/product/jbl-2435hpl-driver-125-30001-00x/ ?

If not, could I expect better subjective and/or measured performance from this beryllium driver with the M2?

JBL successfully built these into the 4367 with a passive crossover. It's tremendous, and is what got me interested in building a pair of M2.

I really have no idea about other drivers with more exotic materials. The M2 is a great starting point. I use the same capacitance and L-pad as JBL. Have many DSP options I can explore, use settings similar to Harman in the end.

I tried to mate it to a 5.5" midrange, but the directivity mismatch made it sound disjointed unless I used a really high crossover which kind of defeated the purpose. I proved to myself, and it was pointed out to me the reasons why in this thread. The D2 horn works well with the 15" woofer. The woofer is specialized, has a profile and variable stiffness to avoid being perfectly pistonic and allowing it to not beam.

A larger mid-woofer with a waveguide would work. Of all the things I tried, a sealed 2.5-way configuration with dual 2216ND woofers worked the best. I still most often have it set up as the simple 2-way version, with sealed instead of ported and a Linkwitz transform to EQ the bass.

 

[MAB]

My mistake, I thought he was including his 98 dB/W/m cones. Apparently full power through them is not concerning!

Easy to mistake, I'm also unclear on the end intent.

 

[DanielT]

I wrote about this horn in another thread, but it's better to bring it up here, so da capo.

Pretty clever of the DIY to make a TV bench out of the horn. High efficiency, due to the horn construction plus the bass driver has high sensitivity, so he only needs 50 watts to power that horn speaker.

He, the DIY, has the speakers close to the horn. With a 24 dB LP-HP filter plus the speakers masking the bass sound, makes it difficult to detect bass direction
from the horn provides opportunities to have a pretty high crossover point. I don't know what he set it to but I guess up to 150 Hz maybe as much as 200 Hz is possible without being able to detect where the bass sound is coming from in that case? More about what was written in that horn DIY thread here:

Spoiler: Horn speaker efficiency and crossover points

I-or:
Given that the efficiency is roughly 10 dB higher than for a 15" bass reflex box of about 100 liters and that the sound pressure level requirements are also not enormous, a measly 1x50 W into 8 Ω is sufficient.

Plus in general it may be of interest:

You should of course optimize all the properties of the system, but often in practice it is a matter of choosing the highest possible crossover frequency because the bass modules have significantly higher sound pressure capacity.

The upper limit frequency for non-detection of direction with bass modules varies with the characteristics of the room and the setup (equivalent absorption area and distance between listening position and bass modules), but typically you can reach up to about 125 Hz without problems here. With bass modules placed near the front speakers you can choose a significantly higher crossover frequency.

All reasoning of this type is based on the front speakers being activated (masking), that the low-pass filtering is steep (at least 24 dB/octave) and that the distortion is low (because otherwise you can perceive the direction of the harmonics).

Driver in the horn:

SB Audience :: ROSSO-15W400

www.sbaudience.com

It reminds me a bit of an old church pew.


As far as I know, the DIY hasn't done any measurements yet, but he's probably theoretically calculated the level of SPL and how far down it goes in frequency.

faktiskt.io • Visa tråd - Exmag bygger nytt högtalarsystem, diskussionstråd

 

[robh36062]

the driver/waveguide combo will require EQ, would I run into difficulties using all passive filters rather than active DSP crossovers?

In a word no the M2 works very well with a passive network.

Rob : )

 

[Newman]

In a word no the M2 works very well with a passive network.

Rob : )

Hi Rob, I am no M2 expert but I thought the DSP applied by the Crown amps was a lot more complex than just the 790 Hz crossover point filters themselves of first order HP and sixth order L/R LP.

In fact, I thought the total DSP network looked more like this simulation on RePhase:

© Thomas Drugeon​

I get the impression that would be best done with DSP and active amps?

cheers

 

[robh36062]

Hi Rob, I am no M2 expert but I thought the DSP applied by the Crown amps was a lot more complex than just the 790 Hz crossover point filters themselves of first order HP and sixth order L/R LP.

I wasn't talking about the entire system, just specially the M2 waveguide and a compression driver. You can take a JBL large format like a 2451SL, use a passive network and get very good results. You can do a passive M2 and while not as smooth as the DSP still very good.

Rob

 

[Audionaut]

There are now many design suggestions for the JBL M2, including alternative drivers, active, passive, and other low-frequency components.

In general, I believe that completely different things are being discussed in this thread.

A full-range horn, such as the Klipschorn or some Acapella models, transmits the entire frequency range via the horn function, including the bass range.

However, speakers that only transmit the mid-high range as a horn (like the M2 for example) are much more common and, in my opinion, are much easier to handle and can achieve very good results.

If I needed large midrange horns, I would take a look at Auto-Tech.

E-JMLC-300 - Horns by Auto-Tech

(Minimal frequency from 500 Hz) Standard: Colour white glossy, without mouting flange and cut of throat Individual order: Different colours, cut throat on diameter, mounting steel flange PDF:

horns-diy.pl

 

[olegtern]

Not for those who appreciate constant directivity...

 

[Audionaut]

There are many other Horns on the Website

 

[olegtern]

There are many other Horns on the Website

I thought you preferred EJMLC among them. Most of them have a similar pattern, exept SEOS as I remember.

I didn't hear EJMLC. I've heard almost all of horns.pl speaker models and overall, I like them. Although when it comes to choosing a horn/WG, I prefer a constant directivity.