asd
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Post by asd on Mar 24, 2018 4:52:25 GMT -5
Hey. Guys i was hoping someone can help med figure out what size cabinet and port i should use with a dayton audio ultimax 18 to get down around 20 hz.
I can't seem to find anything usefull.
Thanks a lot.
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Post by valgolfs on Mar 24, 2018 8:35:35 GMT -5
I have done a little research myself for possible future upgrade and found a staggering amount of threads and forums on that topic. Search the AVS forum or Google "DIY Ultimax 18" you'll find what you need and then some.
Good luck
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Post by emofrmcgy on Mar 24, 2018 9:14:50 GMT -5
Hey. Guys i was hoping someone can help med figure out what size cabinet and port i should use with a dayton audio ultimax 18 to get down around 20 hz. I can't seem to find anything usefull. Thanks a lot. How much usable space do you have for an enclosure ? Are you interested in slot ports(think jtr captivator) or round tube ports(svs pb series). How much power are you using ? What is your plan for a hpf ? |
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asd
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Post by asd on Mar 24, 2018 9:27:31 GMT -5
I have done a little research myself for possible future upgrade and found a staggering amount of threads and forums on that topic. Search the AVS forum or Google "DIY Ultimax 18" you'll find what you need and then some. Good luck A google search was what brought me here. 🙂 |
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asd
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Post by asd on Mar 24, 2018 9:30:39 GMT -5
Hey. Guys i was hoping someone can help med figure out what size cabinet and port i should use with a dayton audio ultimax 18 to get down around 20 hz. I can't seem to find anything usefull. Thanks a lot. How much usable space do you have for an enclosure ? Are you interested in slot ports(think jtr captivator) or round tube ports(svs pb series). How much power are you using ? What is your plan for a hpf ? Most likely a plate amp around 1000 watts. loudspeakerfreaks.com/Product.asp?mfr=Dayton%20audio&part=SPA1200DSP&Product_ID=12547 I was thinking slot ports, but you propably know a lot better then me. I was thinking about 40 inches i hight and 20 in width and depth. At the most. I will propably let the speakers take over around 60 or 80 hz. |
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Post by emofrmcgy on Mar 24, 2018 9:49:54 GMT -5
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DYohn
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Post by DYohn on Mar 24, 2018 11:29:19 GMT -5
A quick model using the T/S parameters of that driver shows if you put it in a 4 cuft enclosure with a 4" diameter flared port that is 18" long, you end up with Fb (system resonance) at 18.25 Hz, and with 1Kw amplifier you can achieve 110 dbSPL at 20Hz. That should do you.
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asd
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Post by asd on Mar 24, 2018 13:31:54 GMT -5
A quick model using the T/S parameters of that driver shows if you put it in a 4 cuft enclosure with a 4" diameter flared port that is 18" long, you end up with Fb (system resonance) at 18.25 Hz, and with 1Kw amplifier you can achieve 110 dbSPL at 20Hz. That should do you. That is a lot smaller than i thought. What happens if i use a 6cuft cabinet? |
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DYohn
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Post by DYohn on Mar 24, 2018 13:55:31 GMT -5
A quick model using the T/S parameters of that driver shows if you put it in a 4 cuft enclosure with a 4" diameter flared port that is 18" long, you end up with Fb (system resonance) at 18.25 Hz, and with 1Kw amplifier you can achieve 110 dbSPL at 20Hz. That should do you. That is a lot smaller than i thought. What happens if i use a 6cuft cabinet? You don't gain that much. Changing from 4 to 6 cuft enclosure size, that increases the dbSPL at 20Hz to 112db and changes the max output by +3db @ 48Hz. Not differences you are likely to hear in normal use. You'll need to shorten the port length to 11.5 inches. |
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asd
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Post by asd on Mar 24, 2018 14:34:55 GMT -5
That is a lot smaller than i thought. What happens if i use a 6cuft cabinet? You don't gain that much. Changing from 4 to 6 cuft enclosure size, that increases the dbSPL at 20Hz to 112db and changes the max output by +3db @ 48Hz. Not differences you are likely to hear in normal use. You'll need to shorten the port length to 11.5 inches. Thanks. The port size might just make me do that instead. I would quite like to keep it rectangular. How did you calculate that if i may ask? I can't seem to get any usefull data out of winisd. I have no idea where you read that. |
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DYohn
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Post by DYohn on Mar 24, 2018 14:40:24 GMT -5
I like using an Excel-based subwoofer calculator called Unibox, developed by Kristian Ougaard. WinISD is quite good but it is more difficult to use. The results should be within a couple % of each other. -edit- here's a link: audio.claub.net/software/kougaard/ubdwnld.html |
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asd
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Post by asd on Mar 24, 2018 15:20:06 GMT -5
I like using an Excel-based subwoofer calculator called Unibox, developed by Kristian Ougaard. WinISD is quite good but it is more difficult to use. The results should be within a couple % of each other. -edit- here's a link: audio.claub.net/software/kougaard/ubdwnld.htmlThanks a lot. I'm on the phone. But i'll check it out tomorrow. |
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Post by emofrmcgy on Mar 24, 2018 15:37:08 GMT -5
 4cuft sealed vs 4cuft ported at 18hz vs 9cuft ported at 18hz |
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asd
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Post by asd on Mar 24, 2018 15:54:19 GMT -5
View Attachment4cuft sealed vs 4cuft ported at 18hz vs 9cuft ported at 18hz That is very interesting. I might as well go sealed i guess? But on a side note. How did you do that? I tried but couldn't get it to do that😋 |
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Post by emofrmcgy on Mar 24, 2018 16:28:38 GMT -5
Get it to do what ? Overlay the separate models ? It may just be the version of winisd I use.
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asd
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Post by asd on Mar 24, 2018 16:35:42 GMT -5
Get it to do what ? Overlay the separate models ? It may just be the version of winisd I use. There didn't seem to be that much of a difference between 4cuft and sealed? |
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Post by emofrmcgy on Mar 24, 2018 16:54:09 GMT -5
I don’t see any reason to go with the smaller ported box with the ultimax.
The 4-5cuft sealed is the sweet spot. For ported you really need to get up to 9-10cuft for that particular driver.
The 5.5db you gain with the double sized box is almost equal to adding a second sub and amp. So twice the real estate but half the cost.
There’s a reason I use a pair of 35cuft front loaded horns in my theater. 😉😉
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asd
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Post by asd on Mar 24, 2018 17:13:27 GMT -5
I don’t see any reason to go with the smaller ported box with the ultimax. The 4-5cuft sealed is the sweet spot. For ported you really need to get up to 9-10cuft for that particular driver. The 5.5db you gain with the double sized box is almost equal to adding a second sub and amp. So twice the real estate but half the cost. There’s a reason I use a pair of 35cuft front loaded horns in my theater. 😉😉 It will be paired with a couple of speakers with 2x12 inch woofers and a fraital horn. So i can live with the loss of a few db if that means halv the size. |
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DYohn
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Post by DYohn on Mar 24, 2018 17:20:48 GMT -5
A 4 cuft vented system seems to be the sweet spot for this woofer. The graph looks like this:  Can you create more output with a larger system? Yea, but the gains are small compared to the size increase in my opinion. But hey, as in all things do whatever floats your boat!  |
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Post by simpleman68 on Mar 24, 2018 18:30:13 GMT -5
A 4 cuft vented system seems to be the sweet spot for this woofer. The graph looks like this: Can you create more output with a larger system? Yea, but the gains are small compared to the size increase in my opinion. But hey, as in all things do whatever floats your boat! Yeah man, no doubt that the law of diminishing returns applies to subs/bass in a BIG way. Scott |
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