# An alternative for HLCD in my install



## StabMe (Nov 17, 2011)

Hey DIYMA ppl.

I have a CarPC in my car with a 3-way + sub setup. I am using a huge 21" Sub from B&C, Beyma 8G40 midbass drivers sealed, Audar PR170 in the door upper corners and Eric's full body horns under the dash, of course.

The system is very clean, crisp, dynamic and loud. Center image is unbelievably strong. But since it is an SUV, image kinda rainbows.

So i was thinking.... I have two spare channels in my DSP (well, soundcard) and i want to install HF drivers in wide mirror corners that will be only active when a special preset is activated. They will take care of HF and horns will be disabled with this preset. This way, when i feel like i won't tolerate image rainbow effect, i can activate that preset and have fun. All the other time i will use my regular preset with HLCDs, i promise! 

The question is - which HF drivers to use that can take some power and match Beymas and Audax? I am kinda used to listen music with highish SPL. I've skimmed through threads and saw some people recommend SB Acoustics drivers. These SB29RDNC look like they can be installed in my car, but will they take the power?

B&C DE35 will definitely take the power and be loud and crisp, but are only usable from like 4KHz and beam like crazy. Not sure if Audax midranges can play that high esp. from that location.

What do you fellas think?


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## metanium (Feb 2, 2007)

The SB29RDNC's you mentioned are very-capable of high-SPL listening. They've handle any power I've thrown at them and have behaved nicely, as long as they were high-passed at 1.5kHz minimum.


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## fish (Jun 30, 2007)

https://www.parts-express.com/morel-cat-378-1-1-8-soft-dome-horn-tweeter--277-084

Always wanted to try these.


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## Elgrosso (Jun 15, 2013)

What about ribbon or planar family?
Always wanted to try this one as it also has a small waveguide (from the coax):
https://radianaudio.com/products/lt6-planar-ribbon/

I tried these ones without the faceplate and had good measurement and feeling at ear level.
But only if vertical, and I couldn’t put them straight enough in my pillars.
In a truck it might be possible, they’re cheap and very sensitive (and got a pair for sale ):
https://solen.ca/products/speakers/home-speakers/ribbons/rt2pro/

Or these, best of the best (got them at home in OB).
The back chamber is kind of big but if you can use the pillar as a closed chamber it could be ok, with or without its waveguide:
Beyma TPL-150 pleated diaphragm tweeter - Beyma TPL-150 - Beyma TPL-150 high frequency tweeter. Beyma TPL-150 high frequency tweeter is available here at US Speaker. Beyma TPL-150 speaker components.

Otherwise, to match the pr17, the TW34 in a big waveguide a la [URL="http://www.troelsgravesen.dk/large_domes.htm]Troels[/URL] were really comparable to my horns in term of stage/feeling.
Maybe not the same dynamic but more refined (and just too big for my dash).


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## StabMe (Nov 17, 2011)

metanium said:


> The SB29RDNC's you mentioned are very-capable of high-SPL listening. They've handle any power I've thrown at them and have behaved nicely, as long as they were high-passed at 1.5kHz minimum.


This sounds very encouraging. I'll be crossing them at about 3000+.


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## StabMe (Nov 17, 2011)

Elgrosso said:


> What about ribbon or planar family?



El, all those suggestions are very interesting. I am just very space-limited. See, the original tweeter location is quite small:










Even though i am open to some modification, there is still not enough space in that location.


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## oabeieo (Feb 22, 2015)

I used a 3khz waveguide with if I remember correctly 
It was the CDX1425 1/2” exit 

It was tiny , and they got extremely loud and clear. 

I used to use it as a super tweeter with my underdash horns and used the little cd on my dash in my old suv when mine would rainbow pretty bad . 

It wasn’t that big and worked very well


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## oabeieo (Feb 22, 2015)

It might have been a b&c (it was awhile back) 

I sold it also so can’t go look. 

Anyways a 1/2” exit CD on a tiny 3k waveguide 

It was bigger than a tweeter but could easily fit in most stock tweeter locations that would accommodate a 2” speaker


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## StabMe (Nov 17, 2011)

oabeieo said:


> I used a 3khz waveguide with if I remember correctly
> It was the CDX1425 1/2” exit
> 
> It was tiny , and they got extremely loud and clear.
> ...


How did you cross them? I imagine, horns played their full band and supertweeters were crossed much higher and simply overlapped? What was the mounting angle? Looking at directivity diagrams of super teeters, they beam very hard.


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## oabeieo (Feb 22, 2015)

StabMe said:


> How did you cross them? I imagine, horns played their full band and supertweeters were crossed much higher and simply overlapped? What was the mounting angle? Looking at directivity diagrams of super teeters, they beam very hard.


Yes they were very directional , and sounded better pollinated at me 

But I installed them pointing up into the glass in the factory spot 
With some eq it worked pretty good it helped bring the stage up a lot 
I used a 6db Lp on horns at 5k and a 6db high pass on the super at 10k 

It took some delays and eq to get it right , but it definitely helped and made it worse in other ways , that’s why I got rid of that car and got a Honda where I sit close to the floor , so my underdash horns work properly, I couldn’t get anything above 4K off the floor and this helped. Width collapsed, and the stage lost a lot of depth but it did what I wanted at the time


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## StabMe (Nov 17, 2011)

Thanks for sharing your experience.

Well, i am leaning towards SB29RDNC, unless somebody advises otherwise.


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## Patrick Bateman (Sep 11, 2006)

StabMe said:


> Hey DIYMA ppl.
> 
> I have a CarPC in my car with a 3-way + sub setup. I am using a huge 21" Sub from B&C, Beyma 8G40 midbass drivers sealed, Audar PR170 in the door upper corners and Eric's full body horns under the dash, of course.
> 
> ...


The dilemna that you are dealing with is a familiar one:

Basically putting compression drivers under the dash is an obvious location. But sometimes it sounds better to have tweeters at eye level.

Yes, I know that there's lot of tricks to make underdash speakers sound higher, but sometimes you just want to PUT them higher. 

I've flipped flopped on this for over a decade, both locations have advantages.

If you're going to go with tweeters on the dash, it's really hard to beat a waveguide. A waveguide easily raises your output by 10dB+.

The lowly SB19 costs $19, and by itself, it sounds like an ol' dome tweeter. But stick that thing on a waveguide and it's a beast.

By far, the most difficult thing about putting dome tweeters on waveguides is that a ton of them simply will not work. Here's a list of the ones that will, to one extent or another:

1) SB Acoustics SB19. This thing works ridiculously well on a waveguide. Literally every horn or waveguide I've put it on, *it just works.* If you look at the tweeter, it has a flange that's nearly flat, and practically no surround. I think this is the secret sauce here; the ideal wavefront for a driver at the apex of a horn is a disc. And though the SB19 isn't a disc, it's so small and the baffle is so flat, it's close enough.

2) JBL GTO SB19. Same name as the SB Acoustics, completely different driver. You can get these on Amazon. Ridiculously small, about the diameter of a penny. The SB is better, because it's more extended. But the JBL is much much smaller. Basically the output of the JBL drops like a rock at 16khz.

3) Just last week I bought a pair of the Tymphany neodymium 3/4" tweeters. I measured them on Friday, the results were not good. I'm going to run some more measurements when I'm back from my trip.

1" tweeters are a complete crapshoot for waveguide use, a lot of them simply don't work. I stick to 3/4" tweeters for the most part. Just easier to get to work on a waveguide.










Here's a measurement of the SB19 on the QSC waveguide. Almost unbeatable polars, just epic.

And note that even a small waveguide goes a long way. A waveguide that's four inches in diameter will control directivity down to 3375Hz.


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## Patrick Bateman (Sep 11, 2006)

Yikes, not much space on that dash. You *might* be able to cram a very small waveguide into the corners.

Normally, horizontall arrays are a bad idea. But a horizontal Bessely array "kinda works."










Here's a five element Bessel array that I made. If you compare the polars to that waveguide I posted five minutes ago, you can see that the waveguide walks all over it. But the Bessel array adds a lot of efficiency over using a single tweeter. So that might get you the dynamics and power handling that you're looking for.

A five element Bessel array that uses 3/4" neodymium tweeters should be much bigger than about 5" in width and about 1" in height. So, it's pretty easy to get it up on the dash.

My array used 2" drivers. If you used 3/4" drivers, the peaks and dips that you see around 4000Hz will be 'pushed' up to about 10khz, simply because the array elements are much smaller.

Downside is cost; at $30 per tweeter, that's about $300 for a stereo array. (Ten tweeters total.)


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## StabMe (Nov 17, 2011)

Yeah, those are nice ideas, but the car lacks space. No space on the dash and i don't really like the idea of using a-pillars as an installation location.

What i want to try is modifying factory locations in sail panels. Aside from SB29, i was thinking about using Fostex FT17H. 




















This seems like the maximum what i can fit in there. But it must be installed almost on axis, right? I think i can fit them aimed at the location between the headrests. Hope this will work.


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## SiW80 (Mar 13, 2019)

Patrick Bateman said:


> The dilemna that you are dealing with is a familiar one:
> 
> 
> 
> ...




Have you got a link to the waveguide you used?

How would you mount it - resting on the top of dash and aimed forward or angled to the middle of between the two headrests?

Simon



Sent from my iPhone using Tapatalk


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## oabeieo (Feb 22, 2015)

StabMe said:


> Yeah, those are nice ideas, but the car lacks space. No space on the dash and i don't really like the idea of using a-pillars as an installation location.
> 
> What i want to try is modifying factory locations in sail panels. Aside from SB29, i was thinking about using Fostex FT17H.
> 
> ...



In 2010 I had a focus and Eric pointed me to a fostex and I tried it and it sounded excellent with horns. No doubt that would be nice , I ended up selling them to a spl guy that ended up blowing them :Banghead: 
I wish I kept them they were so airy and smooth 

I can’t remember which model but they were gold I remember that much


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## Patrick Bateman (Sep 11, 2006)

SiW80 said:


> Have you got a link to the waveguide you used?
> 
> How would you mount it - resting on the top of dash and aimed forward or angled to the middle of between the two headrests?
> 
> ...


Hi Simon, 

That waveguide measurement is using the QSC waveguide, which is no longer for sale.

My new waveguide is largely based on it, here's the response:










Here's a pic, with a soda can for scale. Very easy to fit under any dash.










(Note that you don't need that big enclosure behind it. You can run the waveguide with no enclosure at all.)

Details here : https://www.diyaudio.com/forums/multi-way/319698-unitized-image-control-waveguide-post5776541.html

Price is $150 per pair, or $75 for a single unit.

If you don't want to mount UNDER the dash, you could mount it ON the dash if you cut it up a bit with a hacksaw. It would end up looking like my project from nine years ago:


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