Anyone install a wideband to replace a tweeter in active 2-way setup?

[Justin Zazzi]

For aiming my wideband speakers I went full-crazy and mathed it out.

The goal was to have the left and right speakers be the same angle to the driver's position, and also be installed symmetric in the vehicle. In the diagram I came up with, the left speaker is aimed in front of the listening position by some amount and the right speaker is aimed behind the listening position by some amount (the same amount actually).

Maybe this will help someone.

[mauian]

My understanding from learning from you all and Andy’s tuning guide is that the factory location pointing up at the windshield is one of the better locations for a wideband. If I’m understanding it correctly (and please correct me), if you were to take a wideband and aim it right on axis to you, you have the direct high frequencies but you lose a LOT of the immediate reflections at those high frequencies (because of beaming) that are occurring at the lower frequencies where beaming is not occurring. This causes the high end to sound soft or without sparkle. Andy recommends using a more flat target response at higher frequencies (instead of the usual roll off) for this reason (in this situation with a wideband mounted on axis).

Now with a wideband aimed up at the windshield (in the OEM location in my case), you don’t have this problem, and as Andy puts it, the system acts similar to one with a tweeter and you can tune to a target curve with the usual top end roll off. Im not sure I understand it completely, but I think this is because all that direct (beamed) high frequency energy is immediately reflected from the windshield and reaches our ears very close to the same time as the lower frequencies that aren’t beaming and aren’t reflected off the windshield. Our brains as i understand it are pretty good at interpreting/melding direct sound and very early reflections (just as with the lower frequencies which are reaching our ears directly but also with early reflections in this case).

Andy is careful to point out that use of a wideband like this is not better, but OEMs do it to save on cost.

I would agree; I’m certainly not saying that a wideband is better than a 3-way, nor a 2-way with a woofer selection and tweeter combo that avoids beaming (I really thought my prior combo sounded awesome). I’m just saying that I can hear a difference so far that I like.

I certainly reserve the right to change my mind however and end up joining a club of others that goes back to tweets though

To me, this is one of the things that makes this hobby so cool - trying out these different options, the engineering behind it. It’s interesting stuff and it just so happens to sound awesome too!

Below is a relevant section from Andy’s tuning guide:



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[mauian]

For aiming my wideband speakers I went full-crazy and mathed it out.

The goal was to have the left and right speakers be the same angle to the driver's position, and also be installed symmetric in the vehicle. In the diagram I came up with, the left speaker is aimed in front of the listening position by some amount and the right speaker is aimed behind the listening position by some amount (the same amount actually).

Maybe this will help someone.

I love this! Trigonometry?! And I have no doubt this sounds incredible.


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[Jdunk54nl]

I love this! Trigonometry?! And I have no doubt this sounds incredible.


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It definitely does sound incredible.

[mauian]

For aiming my wideband speakers I went full-crazy and mathed it out.

The goal was to have the left and right speakers be the same angle to the driver's position, and also be installed symmetric in the vehicle. In the diagram I came up with, the left speaker is aimed in front of the listening position by some amount and the right speaker is aimed behind the listening position by some amount (the same amount actually).

Maybe this will help someone.

Just curious, but is this setup SO symmetrical that if you changed the listening position to the passenger seat, you’d have the same angles from each speaker as well?


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[Jdunk54nl]

I think it would be just reverse, but then time alignment would be off.

[mauian]

You can also see where a speaker starts beaming by looking at the frequency charts provided by the better manufacturers with on axis, 30 degrees, and 60 degrees off axis’s. You’ll see the frequency for each one start to diverge from each other at the point of beaming. Take this graph from the Scanspeak Classic 7” mid woofer for example. You can see it starts to diverge as low as 1000 Hz.
Attachment 10816

What many people don’t consider though are all the reflections you get in the tight small space of an automobile. Much of the information you hear is indirect sound as much as it is direct sound and if they don’t match, even when aimed on axis, it will be tough to get everything to sound right. When you LP a driver above it’s beaming point than the indirect sounds will start to become less in amplitude than the direct sounds at the listening position. Having the indirect sound be as close as the direct sound makes tuning easier. This is why using a three way and crossing each driver at or below its beaming point is the best method to use.

Can you be successful with a wide band driver, of course, but you’ll have to be real careful with driver aiming, and you may still not get the same top end sparkle you can get with a tweeter. If you want to use less than ideal factory speaker positions then you may have issues. I’ve seen enough members who went from a traditional two way, replace the tweeter with a wide band and be very excited at first, only to go back to a two way with traditional tweeter, or three way, including myself.

Having the indirect sound be as close as the direct sound makes tuning easier. This is why using a three way and crossing each driver at or below its beaming point is the best method to use.

I was just re-reading this and I think JCsAudio said what I was saying, but better. I think Andy makes this same point but in regard to a wideband pointed at the windshield and why it can work well. The indirect sound is very close to the direct sound in this scenario making it easier to tune.

I am 100% positive Justin can tune better than me so I’ll admit that widebands on axis (or near on axis) for me would likely be challenging, but pointed at the windshield? ...I’m hoping the tuning will be manageable. (I think Nick recently gave this advice to someone with regard to a wideband - that pointing at the windshield will be easier to tune)


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[Justin Zazzi]

Just curious, but is this setup SO symmetrical that if you changed the listening position to the passenger seat, you’d have the same angles from each speaker as well?

I think it would be just reverse, but then time alignment would be off.

Yes and yes. I wanted it to be symmetrical so I could one day try a two-seat setup and I also want it to look good to the eyes, then I covered it all up so nobody can see it lol.

[Justin Zazzi]

Just curious, but is this setup SO symmetrical that if you changed the listening position to the passenger seat, you’d have the same angles from each speaker as well?

I think it would be just reverse, but then time alignment would be off.

Yes and yes. I wanted it to be symmetrical so I could one day try a two-seat setup and I also want it to look good to the eyes, then I covered it all up so nobody can see it lol.

I'm stoked to see so much interest in wideband and also so much pragmatism when it comes to actually using them. I tried many combinations of locations and aiming and I have no doubt if I chose one of the less optimal position or aiming schemes my car would be a trainwreck to tune properly. No doubt about it.

Everything has a caveat and I enjoy the tradeoff of a l super focused center image (and tight imaging in general) vs a more enveloping and spacious sound. I also love that everything is dashboard height with zero rainbow effect own towards the doors. That's just me though!

I am 100% positive Justin can tune better than me so ....

It's been a while since I've done serious SQ tuning or serious SQ judging.
You might be catching up to me!

[geolemon]

You can also see where a speaker starts beaming by looking at the frequency charts provided by the better manufacturers with on axis, 30 degrees, and 60 degrees off axis’s. You’ll see the frequency for each one start to diverge from each other at the point of beaming. Take this graph from the Scanspeak Classic 7” mid woofer for example. You can see it starts to diverge as low as 1000 Hz.
Attachment 10816

What many people don’t consider though are all the reflections you get in the tight small space of an automobile. Much of the information you hear is indirect sound as much as it is direct sound and if they don’t match, even when aimed on axis, it will be tough to get everything to sound right. When you LP a driver above it’s beaming point than the indirect sounds will start to become less in amplitude than the direct sounds at the listening position. Having the indirect sound be as close as the direct sound makes tuning easier. This is why using a three way and crossing each driver at or below its beaming point is the best method to use.

Can you be successful with a wide band driver, of course, but you’ll have to be real careful with driver aiming, and you may still not get the same top end sparkle you can get with a tweeter. If you want to use less than ideal factory speaker positions then you may have issues. I’ve seen enough members who went from a traditional two way, replace the tweeter with a wide band and be very excited at first, only to go back to a two way with traditional tweeter, or three way, including myself.

Much of those lines of thinking led me to an install I did in a Pathfinder I owned about 15 years ago - there were all these little 2" full-range drivers from TangBand and others... Parts Express I'm sure sent out some promotional ad pimping some bookshelf speaker or something, that got my mind going - it was definitely triggered from finding a few drivers that were capable with smooth frequency response plots (both on and off axis) from something like 150hz to 12khz. In other words, imagine that plot with the 7" driver there, but not reaching quite as low, and where the off-axis split happened at around 10khz (maybe higher even) rather than 1000hz. Looked impressive. I tried a bunch of them, I am pretty sure I settled on a Tang Band driver - it had a tiny phase plug, maybe they still sell them. They weren't expensive.

And at the time I was really trying different stuff to see if I could improve imaging, if I could improve the ratio of direct sound to reflected sound, and if that could improve the stereo "image".
Fortunately it was a 1995 Pathfinder with basically door "cards" - so pretty easy to scrap and build my own door panels, just using the parts and clips from the old one. I put a piece of wood with a screw tied to a string between the headrests - representing a point between the headrests at ear level (because I wanted the sound to be symmetrical for both driver and passenger), and I used that string like a compass - I drew matching curved lines on my blank door panels, representing the line where the arrival time at your ears would be theoretically equal - I was aligning them for matching pathlength distances to your ears (or rather, to a point as close as symmetrically possible for both driver and passenger).
I ended up mounting four full-range drivers per side, along this curved line, as close to the bottom corner as I could (I was still able to just barely squeeze two 5.25" midbass drivers below the full-range drivers, also basically matching that curve), and initially ran this without tweeters.

Basically this was a near-field line-array, which was something else I was reading up on at the time, that ALSO led to this experiment...
...because they say "never listen to a line array in the near-field"
What a line array does is re-enforce the sound and project it further, it's why you see them at concerts. Of course, you aren't supposed to listen in the near-field, because you do have multiple pathlength distances between each of the speakers and your ears, so it wouldn't sound good. My thought was "Well - what if we mitigate that by aligning the pathlength distances?"

It actually did largely work, although the most impressive aspect wasn't one that I was expecting: it pushed the stage width way out. I expect this was because four full-range drivers, phase-aligned, mounted close to you - that basically simulates how one of those speakers would sound several feet past and forward of your listening position.

I *DID* end up installing tweeters later, because it did get weak in the upper octave - and much like that graph shows some off-axis breakup , not only was I getting that at wherever that occured on the drivers I selected, but I think that would also be compounded by what's basically the exact same dynamic but not due to cone size, but the array itself, and the fact that I aligned the, to a point between my headrests rather than to the actual point just in front of my driver's headrest (the center of my head).

I was able to get away with running them basically from 10khz and up, if I recall.

Another interesting aspect of this install that was probably "too many experiments in one" was that I ran all those speakers (and two eights in the rear) from a single Alpine 2 channel amp mounted in my headliner, with a hand-made fully passive crossover that made up the rest of my headliner/amp rack, to split that 2 channel signal to [eventually] two tweeters, eight full-range, four midbass, and two subwoofers. All just 12dB/octave, but it sounded great (I didn't go cheap on the caps or coils).

I know I posted this recently... maybe it was this same thread. I should probably look before I type. (EDIT: it was but I didn't really describe the "why")

Oh - at any rate, the other theory I was playing with here:
You'd have four speakers (per side) whose direct pathlength was aligned and strengthened - the primary sound.
And on the other hand, the four speakers reflections - would all be different pathlengths (speaker, to reflecting surface, to your head), meaning they'd weaken each other. Different time arrivals.
I feel like it worked - but that's a hard one to visualize, much less prove.