3-way vs. 4-way

[Dr.db]

Hey guys,

I was thinking about a new project for a friend of mine.
He has listened to my system and wants similar parts, but we want to improve it a little compared to my DIY-speakers.

The following parts are on hand:
2234H
2123H
2441
2405

For those of you asking why 2234h instead of 2235h; the 2235 just sounded to muddy above 300hz and the 2234h with it´s lighter cone would be prefered for the 3-way...
Now there are two possible setup´s we are thinking about.

Option 1:
- 2234H
- 2441 on yuichi-horn
- 2405
- L300-crossover (800hz, 8,5khz)

Option 2:
- 2234H
- 2123H
- 2441 on 2397-horn
- 2405
- 3155-crossover (300hz, 1,2khz, 10khz)


We are wondering which setup would be the best.
A 3-way design with a big yuichi horn that allows to crossover the 2441 at 800hz? The big horn is really tempting and would sound great with the 2441. But on the other hand, the 15" woofer below 800hz doesn´t sound as snappy and dynamic as the 10" cone in the 4-way design...

Looking forward to hear your ideas :)

[1audiohack]

There are so many consideration to factor in a project like this. Some of mine would be:

How loud will it be expected to play?

What will the listening distance likely be?

Is the room live and reflective or absorptive?

Is the music to be listened to mostly field recorded or studio produced?

Here’s my thinking:

The 2397 is dispersive in the horizontal plane and diffractive in the vertical. A 2397 not mounted in a baffle sounds nearly the same from behind as in front. In a live room that could be a problem. With field music like orchestra, the sound from everywhere can be a plus.

If you listen loud, four ways get louder and sound better than two ways.

There is no doubt in my mind that no 15” woofer will pop like a 2123.

If real loud is not a main consideration and if the listening distance is not great, a two way integrates better and easier.

The Yuichi will have better pattern control and as a byproduct of that better imaging and would be my prefered for listening biased to studio recorded music where imaging is more a factor than envelopment of field recordings.

The 2441 should get to about 16k on either horn. I like to let them play up as far as they will cleanly and get the super tweeter to cover only what the large fromat driver wont. The system will play louder while maintaining the big system sound of a large format system.

Any of your listed possible combinations would require subwoofers for me.

These opinions are from a guy who likes the sound of large format HiFiPa. Maybe that disqualifies me. :)

All the best,
Barry.

[Chevelle]

I had the 4-way with 2123 lo-mid which has really "snappy" sound. But what I like more with my 3-way is the sound from a 2" driver as low as possible. I cross the 2445 at 700Hz with my 2311 short horn, let it go up to 16k and have a 2405 on top.
This is best in my ears for short listening distance under 3.5meters in a live room and medium listening levels. The 4-ways only had an advantage at very high listening levels.

Hjalmar

[Chevelle]

Forgot to say that the 3-way sounds good with passive crossover, I use the Nelson Pass modified version of the 3133. The 4-way does not sound best with passive crossover. This system really wakes up when run active with a good amp for the 2234/35.

Hjalmar

[bldozier]

which kind of music are you playing and are you biamp your system

[Ian Mackenzie]

If you can do the big wood horn the run the 2234 up to 650 hertz with 4th or 6th order filters

Using the 2123 with those other drivers is pointless

Besides there will be too much group delay from the 2123 shallow cone to the compression driver.

Of course pro pa guys will quote it out of the “book” but that is not any where refined enough for the financial outlay in a home listening situation.

It will never sound right

The devil is always in the details and that is the crossover phase tracking and getting the 2/3 way to track your preferred room listening curve. That’s not easy as none of this is plug and play

At best you will have a “wall “ of sound. I stopped doing that about 20 years ago.
Greg’s designs are always the first port of call before you go off the reservation into the diy wilderness

With a 4 way is easier for the diy person to manipulate the levels to track your room curve but you still need some tools to measure the levels.

I currently shave the levels on the 43xx 4 ways to within 0.25 dB with LinearX LMS

The balance and audiophile “thing” snaps right in with that order of precision

[1audiohack]

....Of course pro pa guys will quote it out of the “book” but that is not any where refined enough for the financial outlay in a home listening situation....

Hi Ian;

To what does this refer? Sorry you lost me.

Barry.

[berga12]

2234h --> 300hz (or 250hz)
2123 --> 300 (250hz)-800hz
2441 --> 800 - 10.000hz
2405 --> >10.000hz

easy game.:bouncy:

with 2441 you can go down to 500hz in a Yuichi 290 or Iwata, in this case you can get rid of the 2123, but then you loose in "guitar type" instrument reproduction and Low voice dimension.

[Ian Mackenzie]

Hi Ian;

To what does this refer? Sorry you lost me.

Barry.

What l was referring to was going to a pa handbook, making a number of assumptions and then building a (large) pa rig is not the same as designing and testing a domestic hi fidelity loudspeaker or a studio monitor.

[ivica]

2234h --> 300hz (or 250hz)
2123 --> 300 (250hz)-800hz
2441 --> 800 - 10.000hz
2405 --> >10.000hz

easy game.:bouncy:

with 2441 you can go down to 500hz in a Yuichi 290 or Iwata, in this case you can get rid of the 2123, but then you loose in "guitar type" instrument reproduction and Low voice dimension.


Hi

I would suggest to use 2441 (AL) over 1250Hz, as such 'high FR' would not be a problem for 2123, and AL D16R2441 diaphragm will be protected from "over displacement" of too low FR.
Anyhow A290 (with fins) would be my favorite solution. From the Dr. Yuichi measurements, it seems that 2405 can be omitted.

Generally speaking using many drivers would introduce 'comb filter effect' round crossover frequency depending of the listener position
and can not be compensated to all spacial positions.


regards
ivica

[Ian Mackenzie]

The 2234 would be satisfactory up to 1000 hertz

[Dr.db]

Thanks a lot for this great response!

I try to answer your questions, I hope I don´t miss out on any.

@:audiohack, chevelle & bldozier:
The system will be in an average living-room of aprox. 30m² that is about 4,5*6,5m.
That room is a little acoustically treated, some absorbers are mounted for early reflections... But nothing fancy...
The system will have to play loud, but not crazy loud.
Most records are studio recorded.
Music varies from Jazz to Deathmetal or even Electro.

@Ian:"Using the 2123 with those other drivers is pointless"

Before I started this thread I used the search. Most people seemed to favour the JBL 4343 (4-way) over the 4333 (3-way).
There are to possible reasons; either the used 1"-driver wasn´t capable of the lower crossover in the 3-way and sounded stressed. Or the 15" woofer sounded muddy running up to 800hz in the 3-way and the 10" midwoofer in the 4-way gained a lot of liveliness to the speaker.

The first mentioned problem could be adressed by a 2"-driver instead of that 1"-driver as in the 4333 or 4343 which should be much more capable of that 800hz crossover and sounding less stressed.

I know what you are saying; GT designs are very well worked out.
For a person of my knowledge it is usually a wise idea to strictly stick to those proven designs. I kind of did this with my current diy-build that turned out into a 4-way with your help, thanks again.

@berga: "you can get rid of the 2123, but then you loose in "guitar type" instrument reproduction and Low voice dimension"

These are my concerns with the 3-way...
Shure the 2234 will play way up to the 2441 on the big yuichi, but it will never be able to deliver the same liveliness. I expect it to sound more like a hifi-speaker than like the famous JBL straight in your face punch ;)

@ivica: I get what you´re saying, but does this still count in a living-room of 30m² of size? It will play loud, but even with a 800hz crossover the 2441 should be much below it´s limits!?

[Ian Mackenzie]

The depth of the A290 plus the mounting flange then the depth of a 2 inch driver is way more distance thin a 2123 and a 2307/2420

Horn depth 405mm plus the driver vc


http://www.geocities.jp/arai401204/Horn/A290/A290.html

That is why a suggested you look at the 2234 with its deeper cone profile

Group delay of phase shift is the problem above 1000 hz

So use the A290 with a 2 inch driver around 700 hertz to minimise the group delay

The 2334 recone is available and is a proven driver up 1000 hz

Put two in a box like the 4435 and mount the A290 above like the 4435 and you have a class system

If you email Ari at Yuichi he will help you

My advice is keep it simple

The 2235/2231 is not the same acoustically as a 2234 so don’t compare the 4343 etc with anything else

[Robh3606]

That is why a suggested you look at the 2234 with its deeper cone profile

Hello Ian

You might be able to pull the horn a bit forward of the baffle face as well to help offset the difference aka Array Series

Rob:)

[Ian Mackenzie]

Yeah maybe

But the A290 is 400mm deep

I tried that last time with the 2397

The 2397 is nice but not coming from a dark “hole” in the universe

It never sounded right

So l moved it forward

The problem is you then get reflection of the mid driver / woofer in the case a 2122

With the benefit of experience and hindsight l would not do a 2123 under a deep horn

On paper it might seem smart but in reality there are quite audible problems that are not easy to fix (Greg does mention this in comments on the vintage 43xx and it’s something you live with. I have since been able to remove the group delay with a novel
approach)

Back to my recommendation to Dr DB

Use a 2334 a) because it’s one of the few recone you can get b) it’s very good in the midrange

C) a 15 driver dispersion narrows down with frequency typically 100 degrees at 1000 hz

That means the horn horizontal dispersion is going to be a better match with a 15 woofer than a 10 inch mid from 700-1000 hertz

This is audible and Jbl have in recent times gone to great lengths to ensure there is a close match

Alternatively if you can do it get a 2216nd-1

Put the 2 inch driver on the A290

[Robh3606]

With the benefit of experience and hindsight l would not do a 2123 under a deep horn

Hello Ian

I would not either I was thinking the 2234. Like you were saying the 15" directivity will help minimize the reflections off the horn. If he was hell bent on the 2123 I would suggest he ditch the 2441 and use a modern 1.5" throat driver with an aguaplas diaphram on a shallow waveguide.

Rob:)

[Ian Mackenzie]

Zactly

If he wants a wall of sound aka a PA then whatever

Hell why not but a pair of Great Plains 604’s ?

It’s fail safe for a beginner

[Dr.db]

Thanks a lot for these declarations!

I like the idea of keeping the acoustic centers of the drivers close to each other to minimize group delay and phase problems.
The 2234 has a steeper e.g. deeper cone than the 2123, I get you. But this difference might be ~5cm, so most of the offset to the horndriver still remains. So I would think their shouldn´t be a big difference between 2234 and 2123 concerning the offset-issue, or did I miss anything?

I believe the reflections of the 2234 or 2123 underneath the horn would make a much bigger difference.
The narrower the dispersion of the cone driver, the less reflections will bounce of the bottom of the horn. So the 15" woofer should be clearly in advantage here.
You said the dispersion of a 15" woofer around 1khz should be around 100°. What about a 10" woofer at 1khz for comparison?



We are not tied to the 2123´s, if it doesn´t make any sense we will sell them.

There is only the chance to mount one 15" driver because of the size, so no 4435 clone on the bass department...

[Dr.db]

I found this picture with google...
The yuichi horn protrudes a fair bit, would this be ok?
Would you mount the 15" woofer a bit lower to increase the distance to the horn, or can woofer and horn be mounted closely against each other?

79349

[toddalin]

"Or the 15" woofer sounded muddy running up to 800hz in the 3-way and the 10" midwoofer in the 4-way gained a lot of liveliness to the speaker."

This is what I've found and the 2235 starts to get "rough" and looses a bunch of volume around 250Hz. I actually have a null at 250 Hz caused by???

"You can get rid of the 2123, but then you loose in "guitar type" instrument reproduction and Low voice dimension."

This is also the case, especially with acoustic guitar.

What is not mentioned is that you also loose intelligability, imaging, and soundstage because some of the frequencies that provide these cues are MIA.

I have my L200/300s set with a 2251H, open baffle, on the "B" speaker with a 35 mfd cap and I'm thinking 47 mfd would be about perfect into this 16 ohm load. I can "dial" in the volume to this speaker and A/B with/without it. The difference is very real and what is seen on the RTA confirms the audible differences. Without the 2251s, the sound/image just "falls flat on its face" (get more mono with less depth). The 2251 picks up where the 2235 tails off at about 250 Hz.

When I receive my new DMM, I'll be able to measure Henrys and can set the upper limits on the 2251s.

Anyone is welcome to come over to my house to hear the difference for themselves. I live in Orange County, CA.

[ivica]

"...."

This is what I've found and the 2235 starts to get "rough" and looses a bunch of volume around 250Hz. I actually have a null at 250 Hz caused by???

...I live in Orange County, CA.

Hi tod...,

Have You tried the measurements of the 2235H putting the speaker box laying back side on the floor and hanging mic 1 m over it.
I can imagine the mentioned 250Hz (phase difference about 69cm) notch is influenced by the floor driver 'image' , or try to lift the box bottom over 0.5m from the floor surface.

regards
ivica

[toddalin]

Haven't tried that.

The 10" sitting on top of the L200 cabinet gets it well above this level and largely addresses the problem, if that is in fact the cause.

[Ian Mackenzie]

Tod

Have you compared the 2235 with the 2234

Like complete the 430 to the 4435

The 4435 is is totally different loudspeaker in the midrange

[toddalin]

No, and that is why I advocate leaving the mass rings out and just using a sub, under the assumption that the removal of this weight would help the midrange situation.

[Ian Mackenzie]

Thanks a lot for these declarations!

I like the idea of keeping the acoustic centers of the drivers close to each other to minimize group delay and phase problems.
The 2234 has a steeper e.g. deeper cone than the 2123, I get you. But this difference might be ~5cm, so most of the offset to the horndriver still remains. So I would think their shouldn´t be a big difference between 2234 and 2123 concerning the offset-issue, or did I miss anything?

I believe the reflections of the 2234 or 2123 underneath the horn would make a much bigger difference.
The narrower the dispersion of the cone driver, the less reflections will bounce of the bottom of the horn. So the 15" woofer should be clearly in advantage here.
You said the dispersion of a 15" woofer around 1khz should be around 100°. What about a 10" woofer at 1khz for comparison?



We are not tied to the 2123´s, if it doesn´t make any sense we will sell them.

There is only the chance to mount one 15" driver because of the size, so no 4435 clone on the bass department...


There is a lot more to it can l have discuss here

At lower frequencies the phase shift or group delay had a bigger impact

When we look at 700 hertz the acoustic centre of the woofer and the combined group delay of the low pass filter on the crossover results in a far better situation than attempting the 2123 at 1000 hertz or above

In terms of the suitable woofer no one is complaining about the 2216 in the M2

Tad go a step further with a sharper crossover slope of 36 dB that also introduces more group delay

Remember the A290 is a hypex horn and they are longer than the typical exponential horn

Tad monitoring has a reputation for a reason

The alternative if you think you must use the 2123 is mount it on. Pi mid wood horn for 200-1000 hertz

If you intend to use the 2123 then consider a different horn specifically design for a 1200 crossover point

That will have far less depth by design in a modern wave guide

There are lots of options

Frankly if you get the 2234 in there it’s pointless

[Dr.db]

The A-290 is a Hyperbolic-Horn, but there is an Exponential-Horn called A-300 as well.
How would these differ in sound and which of these is to be favoured?

I know it´s hard to tell without any measurements, but how big should the offset be between the 2441 driver and 2234 cone with a 12db crossover at ~700hz ?
Would it be a perfect match like on this photo here?
Probably not, because this is like the TAD monitors and their 36db crossovers introduce more delay than my 12db filter...
79427

So I would probably have to put the 2234 even further behind to match with the deep yuichi horn?
Would it be a smart idea to build something like a waveguide for the 2234? Similar to the Tannoy westminster, even knowing it´s a horn on the tannoy... But I wouldn´t have a clue how to determine the correct curves and angles for the waveguide... maybe a 45° phase on the side´s & top and a straight edge for the bottom!? But I think this will be unpredictable diy-nonsense...
79426


@ivica:
Did you successfully use a l300 crossover with an 2" 2441 driver in the past?
Did you have to change anything, because this network was initially for the 1"-drivers...?

@Todd:
In which bandpass did you use the 10" cone with your L300 ?
Was your 15" a 2235 or 2234?

[toddalin]

I am currently using a 47 mfd cap (common value) to filter out the lows and only bring the unit up enough to "hear the difference." This puts the crossover point at ~210 Hz with the 16 ohm load. I need to work out the upper limit based on testing with the Heil. If possible, I will also keep both of these as 1st order.

For 2241H, I have a pair of 3115 crossovers. These have a 6 mH choke, 27 mdf to ground and 13.5 mfd through 10 ohms to ground (Zobal).

A 1st order Butterworth crossing over at ~210 Hz uses 6 mH to the 8 ohm load. :bouncy: Alternatively, I can change the caps values to alter the slope.

My 15's are AlNiCo 2205s reconed as a 2235s with the mass rings added. These are factory JBL cones and the work was done by Orange County Speaker. The magnets were re-shot, twice, and one was checked on Woofer Tester 2 with Grumpy. For all intents and purposes, the T/S parameters matched those for the 2235 and the second time they were shot, the Bl came out a bit above that of spec. I had the magnets reshot because I didn't like the "dullness" of the 2235s and this was to help out..., not that it did. OCS re-shot them at no charge as the Bl was a bit low after the first shot.

[Ian Mackenzie]

Given this is an idea for a friend and if you don’t have the drivers or the horn your questions are just tempting conjecture

Without a working knowledge of the complexities involved it’s guess work.

Without some real data it’s a guess on what may or may not be a preferred option until such time as you have the horns and some test equipment to measure some approaches to implementing it

If you are looking for more certainty pre purchase of components other than bouncing off ideas it gets back to following a known design.

The closest design is the Tad 2 way

Follow that closely and you will have a higher likelihood of success

The hypex horn allows good loading down to the desired cross point @650 hertz in a 90x40 angle

Yuichi points to some of the compromises discussed such as path length delays on his website

Note the virtual acoustic centre of each driver is seldom the location of the voice cool with the inclusion of the crossover filters

The phase response includes both the drivers physical and electrical characteristics and the crossover filters electrical characteristics

Without some advanced test equipment and powerful sumulator like LinearX LMS and LEAP 5 you would find it difficult if not impossible to implement an optimal design

So what’s the point ?

That’s why you pay the big bucks for a commercial product

Some insights

The 650 Hertz low pass crossover point and a steep crossover point offers several benefits

Lower vertical nulls or lobbing in the crossover region
Minimise the impact of cone breakup beyond piston range of the woofer

Attempting more than a 50mm recess of the woofer is not ideal

Typically a steep 36 dB crossover may incorporate some acoustic roll off from the woofer and group delay.

This under simulated conditions provides phase compensation so the crossover transfer function is close to optimal

The assymetric 12 dB high pass filter in combination with the horns natural high pass function provides the optimal final acoustic Response

Typically this can be validated by reverse of the driver phase and with fine adjustment a uniform deep null > 20 dB as measured at the crossover is visible

If you use a digital amp with inbuilt dsp a lot of the hack work problems above can be resolved for the diy builder BUT you still need to be able to measure it properly

[ivica]

The A-290 is a Hyperbolic-Horn, but there is an Exponential-Horn called A-300 as well.
How would these differ in sound and which of these is to be favoured?

I know it´s hard to tell without any measurements, but how big should the offset be between the 2441 driver and 2234 cone with a 12db crossover at ~700hz ?
@ivica:
Did you successfully use a l300 crossover with an 2" 2441 driver in the past?
Did you have to change anything, because this network was initially for the 1"-drivers...?
?

Hi Dr.db,

Initially I had made no change, but latter, I have reduced 1.55mH to 1mH, and 16uF to 10uF, and have introduced another C round 12uF 'in-series' with 0.3mH as has been in 4345 design. Resistor 7.5 Ohm is put 'in-series' with the mentioned 10uF capacitor.I have sent here its schematics.
I have done such as 2441(Radian dia)&2311&2308 sounded to me "too agresive".

regards
ivica

[dn92]

I found this picture with google...
The yuichi horn protrudes a fair bit, would this be ok?
Would you mount the 15" woofer a bit lower to increase the distance to the horn, or can woofer and horn be mounted closely against each other?

79349

Mount the 15" as close to the horn as possible. On Rey Audio Loudspeakers there is 1cm between TL-1601b and RH-3. On Exclusive 2401 and 2402 there was more space between due to the presence of a grid.

I know (I've seen and heard them twice, the owner is a friend, equiped with JBL 2235H and 2450J) the loudspeakers shown in this picture.
The horn is a clone of TH-4001 made by ALG Audio in the South of France. ALG is also manufacturing Arai290 horns.

[dn92]

Given this is an idea for a friend and if you don’t have the drivers or the horn your questions are just tempting conjecture

Without a working knowledge of the complexities involved it’s guess work.

Without some real data it’s a guess on what may or may not be a preferred option until such time as you have the horns and some test equipment to measure some approaches to implementing it

If you are looking for more certainty pre purchase of components other than bouncing off ideas it gets back to following a known design.

The closest design is the Tad 2 way

Follow that closely and you will have a higher likelihood of success

The hypex horn allows good loading down to the desired cross point @650 hertz in a 90x40 angle

Yuichi points to some of the compromises discussed such as path length delays on his website

Note the virtual acoustic centre of each driver is seldom the location of the voice cool with the inclusion of the crossover filters

The phase response includes both the drivers physical and electrical characteristics and the crossover filters electrical characteristics

Without some advanced test equipment and powerful sumulator like LinearX LMS and LEAP 5 you would find it difficult if not impossible to implement an optimal design

So what’s the point ?

That’s why you pay the big bucks for a commercial product

Some insights

The 650 Hertz low pass crossover point and a steep crossover point offers several benefits

Lower vertical nulls or lobbing in the crossover region
Minimise the impact of cone breakup beyond piston range of the woofer

Attempting more than a 50mm recess of the woofer is not ideal

Typically a steep 36 dB crossover may incorporate some acoustic roll off from the woofer and group delay.

This under simulated conditions provides phase compensation so the crossover transfer function is close to optimal

The assymetric 12 dB high pass filter in combination with the horns natural high pass function provides the optimal final acoustic Response

Typically this can be validated by reverse of the driver phase and with fine adjustment a uniform deep null > 20 dB as measured at the crossover is visible

If you use a digital amp with inbuilt dsp a lot of the hack work problems above can be resolved for the diy builder BUT you still need to be able to measure it properly


Th-4001 can be loaded lower than 650Hz. There have been several DIY loudspeakers inspired by Exclusive 2402 or Rey Audio loudspeakers, using JBL 2446 or 2450 and crossed at 480/500Hz. It is realy working well, I have some friends who have this configuration. The trick is to do a 24/12dB cross over searching for phase aligment between LF unit and horn/compression driver unit.

[Ian Mackenzie]

A shift in frequency (spread) is another method of phase alignment

In fact this is used in a new version of the Altec 604/605 by someone

As l mentioned earlier the newer digital diy modules have adjustment for active crossover networks that help the diy person though the maze of crossover optimisation

That assumes you are comfortable with the signal in the digital space

Passive crossover network design is very complex and time consuming

Active is a better way but still requires optimisation (as text book filters do not account for the characteristics of individual drivers)

I hope to obtain some Tad / Yuichi) horn clones in the new year (given the interest) and work up a validated passive and active network

I realised this may appear over kill here but looking at other diy forums such as the seos wave guide diy space there are a number of people doing optimised crossover networks. That is with cheap drivers compared to Jbl

[dn92]

There is a 24/12 passive crossover at 480Hz here: http://www.cinetson.org/phpBB3/viewtopic.php?f=113&t=38379 made by two skilled former sound engineers, that were used to work with Rey Audio loudspeakers, one at Radio France and the other one on some well known recording studios in Paris.
LF speakers were modified (lower fs) versions of Davis 40rca15, and hf was JBL 2450J in IWT TH-4001 clones.
As stated in the picture, there is a copyright on it and it cannot be used for making money with it.

This passive crossover is easily convertible in an active version, but using digital crossover, especially for crossing around 500Hz symetrical filter orders can be used adding a delay for the LF, as well as FIR filters can be used.

Another possibility is to do a passive correction of the horn response, such it was made in TAD TN-3, and let the crossover part in active, either 36/12, 24/12, 24/24 with delay.

[Robh3606]

Another possibility is to do a passive correction of the horn response, such it was made in TAD TN-3, and let the crossover part in active, either 36/12, 24/12, 24/24 with delay.

That can work very well and what JBL did for the Bi amp version of the 4430/4435. I have done that as well with my active set-up using more modern wave guides. Makes things a bit easier but you need measurement and simulation software to really get it right as you would also need using DSP.

Rob:)

[dn92]

If the driver is a TAD 4001 or 4002, just have to clone TN-3, or better a TN-1 or TN-2 HF but without the HF filter part. You benefit from the level attenuation and therefore less noise from the amp. Valeus for TN-1, TN-2 are available at least by buying the service manual, TN-3 can be estimated from them and some available photos on Internet.

If the driver is a JBL the EQ is a bit different, but can be inspired from the schematic published in the French forum for which I gave the link. In this French forum thread there is another one "à la JBL", only with serie RLC for the EQ, located after the LPAD.

With a passive crossover simulation software such as XSim it is easy to simulate the EQ, and the search for the optimal crossover can be made with an active crossver testing several combinations.

[bldozier]

i am far from a professional stereo designer, however my feeling if the sub is forward firing to the listing position
and playing sting instrument music, with heavy vocal. my opinion would be for the 3way system.

if crossing over at 800hz with a short playing distance i believe the system db level should blend nicer.
with no live music or classical, i don't think at that distance, you would miss the 2123, tied to a 2234H.

if you where playing per say, led zeppelin, with long introductions an a hard drum, i think the 2123 would benefit your
landscape, especially at a closed distance as you described, but i would also like to recommend a 4 way with the 2123.

my feeling is with drum and other percussion instrument at a 300hz cutoff a 21xx is needed to blend the sub, especially if the cabinet
is 43xx by design an not L212 standing, the placement of the bass energizer, tied with the forward firing 21xx should blend that 4 way well.

[Dr.db]

Thanks a lot for all the inspiring answers!!

To summarize this, there seem to be two major opinions.
Most prefer the 3-way setup because of better driver integration and a more harmonious playing of all drivers together.
On the other hand, some favour a 4-way because of the midrange punch of the additional midcone.

The filter-desgin:
Tad used a asymetrical 36db/12db filter for the woofer/horndriver. But what about JBL ? Most networks I´m aware of are symetrical 12db/12db-designs...
Concerning the crossover frequencies; TAD crosses at 650hz, JBL crosses most times at ~850hz (like Everest 66000...). Why does JBL cross that high even with 2"-drivers on big horns?

Dispersion match-up:
We talked about matching the dispersion of the woofer with that of the horn. The 90° horizontal dispersion of the yuichi matches the dispersion of a 15" cone very well.
But how about the horn matching the slot-tweeter?
The JBL 2405 has a 140° dispersion that matches perfectly with the 2397 at 10khz. But the yuichi´s 90° wouldn´t match well with 140° of the 2405!!

@Ian:
Which drivers are you going to test with the yuichi?

[Ian Mackenzie]

I don’t have a Yuichi horn or a two inch driver at present

If anyone following this thread has a similar interest and a Yuichi horn
in mainland Australia and can make the horn available l would be happy to solution a network and respond to your questions

As mentioned in my previous posts you could incorporate an analoge active crossover with “simplified “ passive response equalisation.

This will get you close for diy purposes and save you a lot of time.

Unfortunately passive network design is NOT a guess or a cut and paste of different crossover schematics.

It requires a lot of trial and error experimentation and measuring equipment to get it right. This is what Jbl do.

Given the diy investment involved the above is a prerequisite for the payoff.

Assuming you don’t have an active crossover or measurement tools then my recommendation is pursuing the cloning or diy a Jbl design such as the 4430/4435 or similar.

People like Marchland have suitable active crossover for diy people

[Dr.db]

Thanks a lot for your help so far! :)

If using an active crossover, I would have to use a single capacitor in series with the horn-drivers for protection purpose (turn-on pops etc..).
I remember to use rather big capacitors to inshure their operating range to be a lot lower than the actual active crossover-point...
Which values for the capacitors would I have to use?
2441 will be crossed actively at 700-800hz
2405 will be crossed actively at 10.000hz


If going with the Marchand active-crossover, should I use asymetric filters?
For example the crossover between 2441 and 2405 in the 4355 monitor was at ~10khz with a 12db-lowpass for the mid and 18db-highpass for the tweeter.
Should I copy this asymetrical crossover-sheme?
Did JBL use the 18db-highpass for the 2405 due to more protection from lower frequencies or rather due to a better frequency-response match-up with the midhorn?

[dn92]

TAD asymetrical slopes crossover allows to compensate delay between bass unit and horn compression driver. Not sure if Arai290 will give the same delay as TH-4001.

To integrate the tweeter you should align it in time with the compression.

One possibility for using an analog active crossover would be using an Rane ac23, a JBL M553 or a JBL 5235 with the active 53-3333 filter card, as they have configurable delay for the Lf channel, and in addition use a passive EQ such as the TAD TN-3 was.

The simpler way would be using a digital crossover.

Of course for all of this you need tools for doing your own measurements

[Dr.db]

I tried to calculate the delay caused by TAD´s 36db-Lowpass...

The midhorn uses a 12db-highpass that causes a delay as well for this middriver. So the woofer just has 24db (not 36db) more of filter-delay than the middriver, right?
Considering the speed of sound(343m/s) this additional 24db-filter @650hz (0,7m/s) for the woofer should result in aprox. 20cm (8inch) physical offset, right :confused:

[Ian Mackenzie]

That’s not correct

A visual of the relevant Tad network indicates a 36 dB low pass network

To be exact you need to take a spl frequency measurement and perform minimum phase transform function of the low and high pass using this particular horn/ driver you plan to use to determine the group delay from a reference point ie the front baffle

Ideally you need to do that with your Yuichi horn and proposed drivers.

I have a simulation of the simplified Tad network on my Soundeasy program
But you need to acquire a good measurement kit and simulator software if you intend to pursue a full passive network

[dn92]

This will be also wrong

in low frequencies (below 1kHz) TH-4001 has also some group delay. For TH-4001 minimum phase matches real phase only above 400Hz.

I did some mesurements of TN-2 crossover. LP filter is closed to a Linkwitz Riley 6th order and HP filter close to Butterworth 2nd order. Raw delay between hf and lf without crossover is around 0.8ms (but not constant along the complete bandwidth.

[Ian Mackenzie]

“To be exact you need to take a spl frequency measurement and perform minimum phase transform function of the low and high pass using this particular horn/ driver you plan to use to determine the group delay from a reference point ie the front baffle

Ideally you need to do that with your Yuichi horn and proposed drivers.”

I did say the low and high pass filter functions

At any rate with due respect to Dr.db this discussion is academic at this point and l think it’s is inappropriate to make it appear something the can be simply understood in few forum posts and easily solved in a few minutes.

Unfortunately it goes on and some members feel they have struck pot luck without having any technical skill or background on the specifics of the topic.

I am only providing high level insights. A meaningful discussion requires that the recipient be full conversent with not only the theory and technical problem solving but also the practical application and measurement requirements of this kind of topic.

It isn’t easily understood and not something that can be learnt by googling.

In the end it comes back to the reality of going and doing some practical evaluation of the drivers and horns you have on hand.

This post is an excellent account of the choices and compromises between doing your own diy design and closely following an existing Jbl design .

http://www.audioheritage.org/vbulletin/showthread.php?36686-New-JBL-waveguides-5006812-90x50-vs-PT-F95HF&p=397052&viewfull=1#post397052

[Dr.db]

The longer I´m talking to you guys, I believe it would be the smartest idea for me to use an active-crossover instead of tinkering with passive crossovers. Of course you are right, that measuring equipment is essential to achieve best results. But as my knowledge isn´t up to that procedure by now, I´d be very glad to hear your suggestions on crossover freq. and slopes.

Ian, you have suggested aprox. 700hz for low to mid... Would you try 36db-lowpass on the 2234 and 12db-highpass on the 2441 to start with?
Should I cross at 10khz between mid to high with 12db-lowpass on the 2441 and 18db-highpass on the 2405 as in the 4355-monitors?


If going active, what size e.g. value of protection capacitors do I have to use infront of 2441 and 2405 driver?


We talked about matching the dispersion of the woofer with that of the horn. The 90° horizontal dispersion of the yuichi matches the dispersion of a 15" cone very well.
But how about the horn matching the slot-tweeter?
The JBL 2405 has a 140° dispersion that matches perfectly with the 2397 at 10khz. But the yuichi´s 90° wouldn´t match well with 140° of the 2405!!

[toddalin]

But at 100 degrees, the 2404 would be about right.

[toddalin]

BTW, after adding the 2251Js to the L200/300s, it's hard to listen to music anymore without them. Not perfection, but a bunch closer, including imaging.

[bldozier]

The longer I´m talking to you guys, I believe it would be the smartest idea for me to use an active-crossover instead of tinkering with passive crossovers. Of course you are right, that measuring equipment is essential to achieve best results. But as my knowledge isn´t up to that procedure by now, I´d be very glad to hear your suggestions on crossover freq. and slopes.

Ian, you have suggested aprox. 700hz for low to mid... Would you try 36db-lowpass on the 2234 and 12db-highpass on the 2441 to start with?
Should I cross at 10khz between mid to high with 12db-lowpass on the 2441 and 18db-highpass on the 2405 as in the 4355-monitors?


If going active, what size e.g. value of protection capacitors do I have to use infront of 2441 and 2405 driver?


We talked about matching the dispersion of the woofer with that of the horn. The 90° horizontal dispersion of the yuichi matches the dispersion of a 15" cone very well.
But how about the horn matching the slot-tweeter?
The JBL 2405 has a 140° dispersion that matches perfectly with the 2397 at 10khz. But the yuichi´s 90° wouldn´t match well with 140° of the 2405!!

satellite speakes,

[Ian Mackenzie]

The longer I´m talking to you guys, I believe it would be the smartest idea for me to use an active-crossover instead of tinkering with passive crossovers. Of course you are right, that measuring equipment is essential to achieve best results. But as my knowledge isn´t up to that procedure by now, I´d be very glad to hear your suggestions on crossover freq. and slopes.

Ian, you have suggested aprox. 700hz for low to mid... Would you try 36db-lowpass on the 2234 and 12db-highpass on the 2441 to start with?
Should I cross at 10khz between mid to high with 12db-lowpass on the 2441 and 18db-highpass on the 2405 as in the 4355-monitors?


If going active, what size e.g. value of protection capacitors do I have to use infront of 2441 and 2405 driver?


We talked about matching the dispersion of the woofer with that of the horn. The 90° horizontal dispersion of the yuichi matches the dispersion of a 15" cone very well.
But how about the horn matching the slot-tweeter?
The JBL 2405 has a 140° dispersion that matches perfectly with the 2397 at 10khz. But the Yuichi´s 90° wouldn´t match well with 140° of the 2405!!

See Yuichi's web site for measurements. That will explain thew answer to your question.

The other information is available in the legacy JBL 5234 manual online pdfs.

I am sorry but you need to be able to measure for an active crossover to obtain a useable result.

Some loudspeaker management crossovers have a measurement function.

In addition, you need to learn more about the components you plan to use then evaluate them at a practical level to determine the next steps and manage your expectations.

Your expectations are probably totally differently to mine and my level of expertise and experience and my listening skills are most likely very different to yours.

Any comments I make are only insights, not answers but pointers to considerations along the process of a potential design.

There is no substitute for learning by doing and you will need to go though this like everyone else.

At this early stage you seem to be over thinking your options.

[ivica]

The longer I´m talking to you guys, I believe it would be the smartest idea for me to use an active-crossover instead of tinkering with passive crossovers. Of course you are right, that measuring equipment is essential to achieve best results. But as my knowledge isn´t up to that procedure by now, I´d be very glad to hear your suggestions on crossover freq. and slopes.

Ian, you have suggested aprox. 700hz for low to mid... Would you try 36db-lowpass on the 2234 and 12db-highpass on the 2441 to start with?
Should I cross at 10khz between mid to high with 12db-lowpass on the 2441 and 18db-highpass on the 2405 as in the 4355-monitors?
If going active, what size e.g. value of protection capacitors do I have to use in-front of 2441 and 2405 driver?
We talked about matching the dispersion of the woofer with that of the horn. The 90° horizontal dispersion of the yuichi matches the dispersion of a 15" cone very well.
But how about the horn matching the slot-tweeter?
The JBL 2405 has a 140° dispersion that matches perfectly with the 2397 at 10khz. But the yuichi´s 90° wouldn´t match well with 140° of the 2405!!


Hi Dr.db,

I would start with JBL 4333, or Nelson-Pass network upgrade. As JBL 2312 (&2420/21) has almost linear response, I will say the same as 244x & Yuchi A290 (with internal fins) so almost the same network can be used (I believe some amount of the 2441 combo level has to be reduced 1 to 2 dB).

Using active setup capacitors in-the-series-to the driver: 47uF has to be applied to 2441 and 4.7uF to 2405.
Concerning the dispersion - You will be satisfied.

http://www.firstwatt.com/pdf/art_l300.pdf
http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L300%20Summit%20ts.pdf
(http://manuals.harman.com/JBL/HOM/Technical%20Sheet/L300%20Summit%20ts.pdf)
or some of my experiments, as attached,
regards
ivica

[Ian Mackenzie]

http://www.cinetson.org/phpBB3/viewtopic.php?f=113&t=38379

http://www.geocities.jp/arai401204/Measurement_Page/Experiment.html

http://www.geocities.jp/arai401204/Horn/A290S/A290-S90.html

The above are clues and resources , the facts

It’s obvious you don’t need to have a slot from those measurements

You do need a passive notch filter to smooth the mid bump like in the schematic link
The above are the facts you need to interpret but not over engineer.

As l mentioned earlier it’s not an academic discussion

[Dr.db]

The other information is available in the legacy JBL 5234 manual online pdfs.


That´s a good advice, I just had a look at this document.

It suggest the following protection-capacitors in Table 2:
4uf for 10.000hz (active-xover) with an 8ohm driver (2405)
52uf for 400hz (active-xover) with an 16ohm driver (2441), so I would need 26uf for 800hz (active-xover)

But it also suggest 20uf for 16ohm driver (2441) for 500hz or higher in Table 1. But 20uf is recommended for 16ohm and 1000hz in Table 2.... which is corect now :confused:

@ivica: Why would you use 47uf for 2441 as an protection cab?

Thanks a lot for the shematics!






http://www.geocities.jp/arai401204/Horn/A290S/A290-S90.html

It’s obvious you don’t need to have a slot from those measurements




Thanks for researching the links!


The TAD driver on the yuichi-horn extends to ~20khz (first measurement), but the JBL 2441 driver on the yuichi-horn extends to ~10khz (third measurement).
Why wouldn´t I need a slot, even yuichi himself suggests to use a tweeter with the JBL.

[ivica]

That´s a good advice, I just had a look at this document.

It suggest the following protection-capacitors in Table 2:
4uf for 10.000hz (active-xover) with an 8ohm driver (2405)
52uf for 400hz (active-xover) with an 16ohm driver (2441), so I would need 26uf for 800hz (active-xover)

But it also suggest 20uf for 16ohm driver (2441) for 500hz or higher in Table 1. But 20uf is recommended for 16ohm and 1000hz in Table 2.... which is corect now :confused:

@ivica: Why would you use 47uf for 2441 as an protection cab?

Thanks a lot for the shematics!

The TAD driver on the yuichi-horn extends to ~20khz (first measurement), but the JBL 2441 driver on the yuichi-horn extends to ~10khz (third measurement).
Why wouldn´t I need a slot, even yuichi himself suggests to use a tweeter with the JBL.

Hi Dr.db,

1. If ACTIVE setup, 47uF cap for 2441 would have very little influence on the active network operation
2. As 2441 is very efficient driver (reaching almost 110dB/1W/1m) You have about 10dB headroom to equalize its response over 10kHz, so to include RC
FR compensation over 10kHz, but first You have to do some measurements to get real response Yuichi A290 and 2441 (AL). May be it can be useful without even 2405


regards
ivica

[Dr.db]

Thanks, I ordered 47uf and 4,7uf now. ;)

[toddalin]

The more I listen, the more I like the addition of the 10". It adds a really nice "snap" to the snare drum that you just don't get with a 2235. :bouncy:

[1audiohack]

The more I listen, the more I like the addition of the 10". It adds a really nice "snap" to the snare drum that you just don't get with a 2235. :bouncy:


Another one has seen the light! :)

It’s amazing how smooth one can get a magnitude curve on a two way and it can still miss so much of the dynamics in the middle. Those 10”’s can bring a system to life.

Glad you like them.

Barry.

[Dr.db]

Thanks for sharing your experience :)

[Dr.db]

TAD asymetrical slopes crossover allows to compensate delay between bass unit and horn compression driver.

Maybe my understanding of delays caused by filters is wrong, but I thought these delays only affects the crossover-region/frequencies and not the whole frequency-range of the driver. But wouldn´t you need to offset the complete bass unit e.g. all frequencies to time-align the bass unit with the horn compression driver?

[Ian Mackenzie]

There are limits to the explanations we can provide here.

Have you undertaken any of your own research on the topic?
Correct interpretation of responses on this topic requires an advanced understanding of loudspeaker measurement and crossover design.

At a basic level this is a good place to start

https://en.m.wikipedia.org/wiki/Loudspeaker_time_alignment

You are attempting to jump in at the end of the process and ask for a solution?

Forget about what Tad did because you are not closely cloning that design


Please appreciate this feedback given the time required to respond to your questions.

In terms of making the situation real the expectation would be that you would have access to Clio. Along with detailed view of your proposed design you would send me data files from your measurements. The Smith and Larson speaker tester is possibly another option.

Analysis could then begin followed by design and optimisation of either a passive or analogue or digital network. An appropriate fee would be charged for my time

[dn92]

Maybe my understanding of delays caused by filters is wrong, but I thought these delays only affects the crossover-region/frequencies and not the whole frequency-range of the driver. But wouldn´t you need to offset the complete bass unit e.g. all frequencies to time-align the bass unit with the horn compression driver?

This affect mainly frequencies below crossover frequency, with a varying value depending upon the filter transfer function. Bessel filters are close to pure delay but only below crossover frequencies. TAD used something closed to LR36 filter for LF and close to Butt12 for HF. You have to consider also that there is a non constant group delay provided by compression driver and horn, that has to be part of the game for the time aligment of the two drivers. As Yuichi horn is different from TH-4001 there should be adaptation in the crossover components values.

You have to be able to do measurements (freq response and impedance) before thinking modifying the TAD schematic values for adapting them. Start also by using a digital crossover together with your measurements, and when crossover will be finalised move to passive crossover engineering.

You can find TN-2 schematic there: http://forums.melaudia.net/attachment.php?aid=15946

[Dr.db]

Thanks for the link to wiki and the TAD-shematic!

We will use an active crossover for this project to get started. Probably we´ll stay with this, as I have very limited skills in passive crossovers.
Using the TAD crossover with our JBL components probably isn´t working at all, so we`ll better stick with an active xover.

Ian, what I had discovered before asking is that phaseshift caused by a filter changes over the frequency-range. This made me wonder, if the attempt of an electronic offset (crossover) has the same effect as a physical offset regarding the time-alignment. Reading your link, the pictures do say so.
I´m aware of my lacking knowledge, so I´ll try to avoid going into detail any further.

Just let me ask this simplified: if a compression driver is located significantly behind the woofer because of a deep horn, is a higher crossover-slope on the woofers lowpass a smart idea in most cases?
Did JBL use a 24db lowpass (woofer) and 12db highpass (midhorn) on the DD66000 for the same reason of time-alignment? Or is this because the acoustical roll-off of the midhorn(~12db) sums with the electrical roll-off (12db) a 24db slope and therefor the lowpass needs 24db slope as well to match up?

[dn92]

JBL 2" drivers in TH-4001 response is a bit different but not so much. I've EQ settings for this that have been tried on the loudspeakers of a friend (2446J on TH-4001 horn clone).

[Ian Mackenzie]

Thanks for the link to wiki and the TAD-shematic!

We will use an active crossover for this project to get started. Probably we´ll stay with this, as I have very limited skills in passive crossovers.
Using the TAD crossover with our JBL components probably isn´t working at all, so we`ll better stick with an active xover.

Ian, what I had discovered before asking is that phaseshift caused by a filter changes over the frequency-range. This made me wonder, if the attempt of an electronic offset (crossover) has the same effect as a physical offset regarding the time-alignment. Reading your link, the pictures do say so.
I´m aware of my lacking knowledge, so I´ll try to avoid going into detail any further.

Just let me ask this simplified: if a compression driver is located significantly behind the woofer because of a deep horn, is a higher crossover-slope on the woofers lowpass a smart idea in most cases?
Did JBL use a 24db lowpass (woofer) and 12db highpass (midhorn) on the DD66000 for the same reason of time-alignment? Or is this because the acoustical roll-off of the midhorn(~12db) sums with the electrical roll-off (12db) a 24db slope and therefor the lowpass needs 24db slope as well to match up?

It’s a case by case question

The Jbl drivers and horns are different to yours. Their combined electrical-driver slopes where symmetrical AFAIN. Read the white paper

In theory a steep slope on will have less lobe related problems in the crossover region

But every design has a hierarchy of design goals and they are often competing goals.

Ideally you want to set of complementary compromises

But listening tests are also required in each case.

The Tad woofers breakup quickly (l have been told) so a steep slope made sense.

They chose a lower slope for the horn. There may have been several reasons for that?

You can’t guess that.

What l am saying is there is a hierarchy of considerations.

It’s too early to be theorising. Don’t get hooked on over thinking a solution or over reading.

There is a tendency to become self obsessed about a particular topic if you over read.

It’s not real and you are not present.

It’s like a person who reads a book on how to swim.

They then dive in and sink. It goes on.

A successful loudspeaker is NOT 95% thinking and design, 5% build.

Discussions here have very limited impact on your success unless you are closely following a Jbl design.

First are your drivers. Understand them, listen to them.

Get your hands dirty and setup modular test boxes

Do your measurements and listen on your drivers

You then use a dsp crossover for exploration of flexible crossover options.

Pink noise or off station FM noise is useful to assessing the blend.

Listen and measure.

You can then make some informed decisions

Bread crumb: there tends to be a very narrow sweet spot in terms a fine adjustment of the crossover in both listening and measurement

That is why you should invest in a measurement device

[Dr.db]

@dn92: Would you share your eq-settings?

@Ian: Thanks a lot so far, I´ll continue with extensive listening sessions now ;)

[Ian Mackenzie]

Below is an example of two way system vertical crossover lobes

Passive network 36 dB slope , crossover point 800 hz

The key is to obtain exact phase tracking at the crossover point.

Attached is the frequency response from the design point and vertical polar responses for both in phase and reverse phase of the drivers.

The data is actual raw driver measurements of an AE15M and a Tad 4003 on AH700 conical horn

The computer can very accurately simulate the proposed crossover design schematic within the crossover region.

By reversing the phase of the drivers cancellation can be seen of nearly 40 dB at the crossover point.

The primary impact in the vertical lobe is at 800 hz due to steep crossover slope.

In phase the lobe is exactly where l designed it in the crossover region.

This is only possible with quality measurement data, powerful simulation software and experience.

Even with the computer this took a while with several different crossover attempts.

It is optimal outcome is very sensitive to small changes in the crossover design and location of the drivers.

I am not setting the bar here but to illustrate the theory and the practical outcome of crossover network operation.

[Dr.db]

Thanks Ian, those graphs are very descriptive.

Maybe reversing the polarity on one of the drivers while listening and playing a test tone of the crossover frequencie gives a first guess if phase is correct?

[Ian Mackenzie]

In the crudest sense a sine wave sweep at 1 m with your trusted spl measurement of the dip.

The actual crossover slopes need to be correct prior to that approach

I have previously indicated an active crossover solves the problem of complex and often difficult passive crossover design and implementation.

You still need a trustworthy measurement device.

The alternative is closely follow an existing Jbl design.

The thing is Andrew Jones (renowned loudspeaker designer) can design and get to market a really good sounding cheap loudspeaker.

So the tipping point for your own design diy loudspeaker is shelling out a modest outlay on an active crossover and a trustworthy measurement kit.
That really is the gateway for rolling your own diy loudspeaker.

Conversations are best about measurement techniques. Not the end solution.

That will prove a valuable long term investment.

[Dr.db]

Sounds reasonable, thanks a lot for your help so far!

[Dr.db]

Regarding the crossover between 15"-woofer and 2"-driver on yuichi horn there are at least two contrasting demands:

On the one hand you want the crossover to be as low as possible to increase group-delay of the lowpassfilter on the woofer to help compensate for time-alignment to the deep horn-profile. So a ~650hz crossover would be desired.
On the other hand you want the crossover to be a lot higher so that the 15"-woofer reaches almost the same dispersion as the yuichi horn and they match up nicely. So a ~1000hz crossover would be desired.

I know it always comes down to some kind of compromise, so which of these two aspects is more important and where about would you set the crossover?

[Ian Mackenzie]

The best course of action is to commence evaluating your drivers yourself and the facts will help you make a decision.

[ivica]

Regarding the crossover between 15"-woofer and 2"-driver on yuichi horn there are at least two contrasting demands:

On the one hand you want the crossover to be as low as possible to increase group-delay of the lowpassfilter on the woofer to help compensate for time-alignment to the deep horn-profile. So a ~650hz crossover would be desired.
On the other hand you want the crossover to be a lot higher so that the 15"-woofer reaches almost the same dispersion as the yuichi horn and they match up nicely. So a ~1000hz crossover would be desired.

I know it always comes down to some kind of compromise, so which of these two aspects is more important and where about would you set the crossover?

Hi Dr.db,

I will not pay any attention about 650Hz dispersion characteristics of A290 either 15"-woofer.....
talking about group delay of the woofer with the passive network near 650Hz all the elements have to be taken 'into account'.
1ms delay would correspond to 34cm. May be 4th order passive filter would help

regards
ivica

[Ian Mackenzie]

In reality depending on the dimensions of the horn mouth and profile the dispersion may be wider than you think

The woofer may also sound terrible above 650 hertz

So you need to do some home work and determine what the horn and woofer is doing

[Dr.db]

I got you...
So far I have to say, the TAD 1603 isn´t super snappy in the upper bass, but I was impressed how clean it sounds even in the mids. I´ve had woofers that thrilled me more in the upper bass, but the TAD isn´t doing anything wrong at all in the mids. As I said, very clean.
I wouldn´t mind crossing it over higher...
But so far I can´t judge the yuichi, as I havn´t build or listened to one.

[Ian Mackenzie]

In that case to close the loop on your questions l would simply email Yuichi and get his feedback or recommendation on a crossover point.

Auditioning is often the only way to do this.

He has helped numerous people with these horns and would no doubt help your get started.

The A290 might look similar to a Tad horn but small details are important.

Ie the depth and other dimensions are probably different to the Tad and you might not be using a Tad driver. Your woofer is a 1603 not a 1601 .

Therefore any desire to clone a Tad monitor is out the window

http://www.technicalaudiodevices.com/lf-units

[Dr.db]

I will email yuichi ;)