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Multi-Way Conventional loudspeakers with crossovers

Is it possible to cover the whole spectrum, high spl, low distortion with a 2-way?
Is it possible to cover the whole spectrum, high spl, low distortion with a 2-way?
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Old 20th May 2019, 05:47 AM   #511
Ro808 is online now Ro808  Netherlands
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Quote:
Originally Posted by whgeiger View Post
Based on the interest here, the following is a worth while read, if you have not already done so.
A lot of the JBL/TAD product referenced here is the results of Bart's engineering efforts. WHG

I guess this is the story you refer to (from the JBL history):

Dr. John Frayne (Westrex), having worked with Jim Lansing previously, met with Bill Thomas and Bart Locanthi for a discussion that would become legendary. Dr. Frayne brought along an example of the Western Electric 594A compression driver.
He had a simple question: “Can JBL make a permanent
magnet version of this driver?” The answer would result in the famous JBL 375.

The 594A had been out of production since shortly after
Western Electric left the cinema market in 1938. Previously, it had been at the heart of Western Electric’s large cinema loudspeakers. It was a field coil compression driver that was unique in its size and output, utilizing a 4" diaphragm, 2" throat exit and four-slit, circumferential phasing plug. Since discontinuance of the 594A, Altec’s smaller 288 compression driver ruled as the standard high-power transducer for cinema systems. Westrex believed that a permanent magnet version of the 594A could offer a competitive advantage against the Altec 288 because of its greater output.

Last edited by Ro808; 20th May 2019 at 05:54 AM.
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Old 20th May 2019, 06:35 AM   #512
camplo is online now camplo
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Quote:
Originally Posted by mitchba View Post
Hello camplo,

I have the JBL 2453h-SL 4" compression drivers mated to the JBL 2384 waveguide using a linear phase digital XO at 630 Hz as recommended by JBL when using active XO. The 2453h-SL are the cheapest 4" CD's as you can't drop in different phragms. I am very happy with the sound quality from these CD's. Very smooth and low distortion. Recommended.

If you go all the way back to post #15, I linked to a member of the AVSForum that tested a number of JBL CD's including the D2 on the 2384 waveguide, which wasn't the best match: Just purchased a pair of JBL 4722n speakers. - Page 122 - AVS Forum | Home Theater Discussions And Reviews It looks like the D2 is best XO'd at 800 Hz and designed for the M2 waveguide.

The advantage of the D2 driver is it's ring radiator extension as the 2nd diaphragm. I am fortunate of the Ti aquaplas, but the D2 has the extension to make it to 20 kHz for realz. The issue with the Be drivers is that they do not extend as high as the Ti aquaplas drivers and some add a supertweeter...but some don't and think it "marginally" sounds better than the SL JBL drivers. I don't know if the (significant) cost is warranted...

User pos has posted the eq for the M2 system so you can see for yourself what eq is being used: JBL M2 crossover - Google Docs

The JBL M2 and Revel Salon2 shootout folks refer to is a lot more even than most folks think. I think the real difference is the narrower directivity of the M2 as indicated by the "spinoramas". One may prefer more room sound if listening to classical music whereas others prefer more direct sound for rock (myself included).

My JBL 26SH-1 dual 15" driver are similar to the 2216nd as they are both dual voice coil and neo mags, but the latter being higher quality than the "cinema" version I use. Personally, I love the bass and midrange of these 15" drivers, they really track nicely, with a smooth response. I have not heard the AE drivers, but lots of folks love them for sure.

In my previous post, I linked to a diy M2 build thread. It is worth the time and effort to read through it. Regardless of what you choose, make sure you model the response with the cabs to get the low end you are looking for.

I am pretty happy with my 2 way with the addition of the subs:

Click the image to open in full size.

Click the image to open in full size.

Good luck with your build!
I've come across some of your post in the past and appreciate you sharing you experience. POS did a comparison of BE/Aquaplas/Ti diaphragms, Aquaplas has more dampening then all. Its response is smoother is well, pre-eq. I once considered the same waveguide, I'm don't remember what persuaded me to switch to a tractrix, maybe it was the uniform dispersion regardless of horizontal/vertical angle.

What do you guys think of a 2-way with dual 15'ms vs a 3 way with a 15m mid and 15h woofer?

I just found the force flat feature on winisd, lets see where this takes me
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Old 20th May 2019, 06:40 AM   #513
Ro808 is online now Ro808  Netherlands
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114dB at 30Hz at Home.

2x 15M would likely give you extra output overall, but Iam not sure about excursion limits.

Last edited by Ro808; 20th May 2019 at 06:57 AM.
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Old 20th May 2019, 06:49 AM   #514
camplo is online now camplo
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Quote:
Originally Posted by Ro808 View Post
Camplo, you said you crossed both JBL and Ae at 30Hz, do you mean a HP?

114dB at 30Hz at Home
I meant on the modeling graph the plot crossed 30hz at the particular spl.

Forcing the response to flat has shown that the M2 woofer and the 15m are somewhat similar, though the M2 woofer has more excursion.

I am modeling for perfection at high level in order to expose weaknesses.
114db at 30hz....sounds like an extra fun movie night.

Still -
Quote:
What do you guys think of a 2-way with dual 15'ms vs a 3 way with a 15m mid and 15h woofer?
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Old 20th May 2019, 07:16 AM   #515
Ro808 is online now Ro808  Netherlands
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Provided the 2x15M doesn't bottom out, that's what I'd prefer.
Less excursion is better in my opinion.

Last edited by Ro808; 20th May 2019 at 07:30 AM.
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Old 20th May 2019, 07:35 AM   #516
Bill Coltrane is offline Bill Coltrane  Netherlands
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Quote:
Originally Posted by Ro808 View Post
Not saying it doesn't, or can't work. From my experience both in small spaces and definitely in cars, very low frequency reproduction is not only compromised but often also highly uncomfortabele. It always puts a grin on my face once the panels begin to rattle in a €200.000 car. Even with the sub's output level behind the other channels.

But hey, it's a free world. This is just a matter of preference and opinion.
No its not a matter of preference and opinion.
Nature works like that or it doesn't.

In this case, multiple subs work and you can reproduce frequencies longer than the dimensions of the room.
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Old 20th May 2019, 07:36 AM   #517
Ro808 is online now Ro808  Netherlands
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Mitch that's a Nice setup. I bet IT rocks.
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Old 20th May 2019, 07:39 AM   #518
Ro808 is online now Ro808  Netherlands
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Quote:
Originally Posted by Bill Coltrane View Post
No its not a matter of preference and opinion.
Nature works like that or it doesn't.

In this case, multiple subs work and you can reproduce frequencies longer than the dimensions of the room.
Congrats!
I have stated twice that I DON'T think IT CANNOT be done.

Last edited by Ro808; 20th May 2019 at 07:45 AM.
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Old 20th May 2019, 08:00 AM   #519
phase_accurate is offline phase_accurate
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Quote:
Le (voice coil inductance) is the LEAST relevant parameter in a Woofer. End of story.
Well it is not that simple I would say.
While you are definitley right when it comes to subwoofers this is not actually true for every type of woofer. When the driver has to reproduce midrange as well then there is not just the influence on frequency response (which can be dealt with) from Le but also the non-linear behaviour of Le versus coil position. This leads to midrange IMD. There are of course drivers with high Le and low variance of it where it doesn't matter that much and it might not matter very much when Le is small but the variance is increased as long as one stays away from the pole that is defined by Le and Re.
OTOH I built a 2x15" in order to have a speaker with very low excursion even at loud (but not insanely loud) listening levels. In this case it doesn't matter that much either I guess. When I have some time to spare I will remove one of the Woofers from the cab and check whether I can measure midrange distortion in the voice-coil current as a function of excursion from low frequencies.

Quote:
It appears for the 4367 the part number is different, ending with 002 instead of 001.
IIRC the 4367 version is a little like the TADs form the TSP point of view.

Regards

Charles

Last edited by phase_accurate; 20th May 2019 at 08:03 AM.
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Old 20th May 2019, 08:14 AM   #520
bbp is offline bbp  China
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Quote:
Originally Posted by camplo View Post
I've been on a quest to build my own own reference monitor. In that journey I've come to know the JBL m2. Maybe its highly prized for its flat response but all I see is another 2-way. There are already flat two ways on the market. So not sure what the hype would be around this speaker, beyond having accuracy and spl, making useful for far field as well as near field.
As a full-range solution if a 2 way that took care of sub bass, gets rid of another cross and thats cool. I've found a driver that could be used for the top

FaitalPRO HF146 - 1.4" Compression Driver

A woofer for the bottom can be found. The question is, how is a woofer that is going to be easily responsible from 30hz to ~1000hz going to behave? Lets say we are auditioning rap, edm, or some other deep bass reproduction that causes high woofer excursion, how is the top range of that speaker going to sound? It seems to me a 3 way is almost always better, but I'm not the finally say, the results are, anyone have a strong opinion on this?
How about my work:
15WU/8741+6640, 10 Liter cabient.

SPL and Distortion measured @ 100W input, 1m distance:
Click the image to open in full size.

I will never use 100W input power for this speaker, because my small listening room is only 7m^2.
Attached Images
File Type: png 2-way 100W input SPL and THD.png (58.4 KB, 188 views)
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