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I've looked at that driver. Take that 96 dB with a grain of salt, it is measured at 2.83V, which is a 4-watt number with a 2-ohm (dual 4 ohm coils in parallel) driver.


In other words - the marketing department got their hands on the numbers. It is not a false specification, it is just stated in a way that makes their stuff look that much better.
 

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Quote:
Originally Posted by Oklahoma Wolf /forum/post/19167755


The Infinity models very well for me in a 17Hz TH. Excursion might be a limiting factor there, though.

Yup, the excursion blows up as power is applied. 16 volts takes it over xmax at 23 Hz. Only makes 110 dB.


Next....
 

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Quote:
Originally Posted by stgdz /forum/post/19165807


Looking at the LAB 12 driver it looks really close to what danley uses in the DTS-10. Since it is made by emminence did they just up the X-max on it and lower the FS a bit?

Physically the magnet structure is different, with vents that the LAB 12 doesn't have, which appear borrowed from the Magnum/Definimax series. Those vents are present on the new LAB 15. If a change was made in Fs chances are it was made higher. The acoustic load of a horn lowers the effective resonance of a driver. Often that must be compensated for with a small rear chamber; that is the case with the LAB 12. Since a TH has no rear chamber that's not an option.
 

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Quote:
Originally Posted by Bill Fitzmaurice /forum/post/19168386


If a change was made in Fs chances are it was made higher.

Yeah, I'm of the opinion that it's what I call an 'ideal' BLH alignment which would require a much higher Fs, not to mention other spec differences.


GM
 

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Discussion Starter #26

Quote:
Originally Posted by lilmike /forum/post/19167898


I've looked at that driver. Take that 96 dB with a grain of salt, it is measured at 2.83V, which is a 4-watt number with a 2-ohm (dual 4 ohm coils in parallel) driver.

I had a feeling marketing had something to do with that. I just don't like what Infinity's become in general - I miss the days of the IRS speakers



Back in the day, I would have given just about anything to own an IRS-V system.
 

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Quote:
Originally Posted by lilmike /forum/post/19167925


Yup, the excursion blows up as power is applied. 16 volts takes it over xmax at 23 Hz. Only makes 110 dB.


Next....

well I wasn't aiming for something super deep or loud. I all ready had a 24" THT with a 15" driver, I didn't have enough room for an additional 24" so I built a smaller one and tried to pick out a cheap driver as I couldn't rationalize spending the money on a 12" DVC that was close to in price of the 15" DVC.


So I set a price of about 60 bucks for a driver and originally found the 1252w's below that price(they were used in Passing Intrests build) but after digging around a bit more I found the 1262 so I went with it. The driver was cheap($60) and it met most of the requirements I was looking for. It balanced out the horrible room I currently have though.



That 8x quatro setup that maxmercy posted sims for looks really tempting but that would mean I have to get new amps, more subs, and build more boxes but it would get me into the unicorn territory of below 15hz.

 

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Quote:
Originally Posted by stgdz /forum/post/19168970


well I wasn't aiming for something super deep or loud. I all ready had a 24" THT with a 15" driver, I didn't have enough room for an additional 24" so I built a smaller one and tried to pick out a cheap driver as I couldn't rationalize spending the money on a 12" DVC that was close to in price of the 15" DVC.


So I set a price of about 60 bucks for a driver and originally found the 1252w's below that price(they were used in Passing Intrests build) but after digging around a bit more I found the 1262 so I went with it. The driver was cheap($60) and it met most of the requirements I was looking for. It balanced out the horrible room I currently have though.



That 8x quatro setup that maxmercy posted sims for looks really tempting but that would mean I have to get new amps, more subs, and build more boxes but it would get me into the unicorn territory of below 15hz.


Don't get me wrong - if it works for you, in the enclosure you're using it in, that's great. You're using it in a front-loaded horn, not a tapped horn, and it seems to be well-suited to that. It's all good.


I just wanted to point out that the driver is not not as efficient as marketing would have it seem, and that its performance in a tapped horn is not really good enough to warrant any future effort by me in that regard, hence the "Next....".
 

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Discussion Starter #29

Quote:
Originally Posted by lilmike /forum/post/19169612


hence the "Next....".

DIYMA R-12



Of course, one has to find them to do something with them... and the Shiva X2 is a bit more capable...
 

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I'm still keeping an eye out for the perfect horn sub that would fit between wall studs and be about 90+ tall so I could drywall around it, leaving only a small portion sticking out.


I'd want two of them. One for the front and rear of my room. And capable of being nearly flat to 15hz.


But it would have to beat my pair of 15" 16hz tuned Tempest X for output. And that seems to be the tricky part.
 

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Discussion Starter #31
Interesting idea, but the problem there is that any horn with a 16Hz corner that can put out that kind of SPL is going to wind up being rather deep, even at 90" tall. The one I already built is 74" long, and still ended up being 42" deep.


The double SDX one should end up being a lot more friendly to this kind of thing in terms of width, but I don't know if it'll get you the output you want unless I start increasing the horn flare and the size along with it. It might do it as is in room, but I don't know what the room is like. And this will still end up being deep.


It's a challenge, for sure.
 

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Nearly flat to 15Hz, with real output, and inwall is out.


Mid/upper-20s in four stud bays, maybe.
 

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Discussion Starter #33
After giving things a lot of thought, I decided that I just can't do it... the 483L version is just not what I want from this project. I feel it's just pushing things too far toward small size. In fact, there's some temptation to let it get even a little bigger than this revision.


So, here's revision 3. Basically, all I did was take version 1 and tweak it for a parabolic flare until I was happy. The throat and mouth are both smaller, but the design is at 521 liters and probably going to stay there unless someone spots a bug I missed.


Below is the half space SPL graph at 300 watts. This takes the woofers just a hair over Xmax at about 19.3mm at 21Hz according to the sim, but that won't be a problem. The TB horn's woofers in reality take more effort to hit Xmax than Hornresp said they would. The SDX's won't even be stressed at this level.




The 300W quarter space graph shows this thing already playing above the 120dB level above 16Hz. This shouldn't be hard to achieve in room. Especially my room, where the TB horn is already hitting 120dB peaks at listening position. This one will be much more capable than that horn.

 

whsdxr3.txt 0.4130859375k . file
 

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Hi Oklahoma Wolf,


I've been modelling the CSS SDX10 for a while, and am happy that somebody with building experience is taking this one on in a tapped horn.


As to the Thiele/Small parameter, the Le is listed as 1.42mH (I have noticed, that the SDX10 likes about 2_to_5mH/0.10_to_0.25_Ohm in series, and it strongly affects the frequency response, as a minor point two of these in series give at least 10 Ohms nominal impedance.


Nice work, hope you'll get to build it.


Regards,
 

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Discussion Starter #35
Oh, it's getting built... I just don't quite know when yet. A lot depends on money and weather. I hope to have the woofers by January... after that it'll be down to how fast mother nature can get the temperature over 10 degrees Celsius and the snow melted.
 

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Discussion Starter #36
Got a preliminary fold done this evening - it turned out to be too short so I'll have to work on that before I share the drawing.


Sketchup wasn't nice to me at first, but I prevailed. The result was a double fold sort of like the last one I built, only with the horn mouth in a different place. The final size of the design had I accepted the result would have been about 33" x 79" x 13.5" - a bit more low profile than my existing horn. But there is a significant length error that raises the corner to 18Hz, so the final product will turn out to be longer than 79." I can go to 84" in my room, and after that I have to find another folding scheme. Will report back when I have time to work on this some more and get the horn to the proper length when folded.


Edit - why not share anyway:




This is the basic shape I got out of it. The mouth is still boarded over, but it's at the bottom left corner. Woofers go on either side of that faint black line on that second horizontal panel down from the top.
 

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Discussion Starter #38
Heh - that does ring a bell. I actually have a completely different fold I want to try as well before I try to redo this one. It may result in the box being not quite so long and a bit wider. With my luck, it'll probably make things too complicated and still turn out too long.


Edit - refolded my first attempt to correct length errors. Box is now 84" x 36" x 13.5." Hornresp says the corner is 17Hz due to path length still coming up 19cm short. That's... acceptable. I'll give it another attempt though to try and correct some step errors.
 

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Discussion Starter #39
Got my alternate fold idea done - here's the result:




As currently modeled, it is 7' long and 44" wide. There is a big length error in this one too - it's almost a meter too long. As a result it moves the corner down to 14.5Hz at a significant SPL reduction. On this one I folded it into a seven foot package just to see if the plan would work... accuracy could come later I thought.


Honestly, I think I like this idea better than my original folding plan. All I have to do is get that extra meter off the length.


Edit - had a better idea. This brings the corner even lower to 14Hz. Will probably use this idea and just fix the length to get back to 16Hz.




You can see where I used the measuring tape to be sure the first woofer would mount properly.
 
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