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First HT DIY Subwoofer for a noob on a budget..

31668 Views 99 Replies 7 Participants Last post by  jeffrobinson
Good evening gentlemen,
I'm a noob who bought a pair of Phoenix Gold Ti15d's from Sonic years ago planning to stuff them in a suv. Fast forward 9 years, they were never installed. Want to build a home theater sub for the kid and I need the right box the first time due to a state employee budget. Picked up a Bash 300w amp at partsexpress for one Benjamin. Phoenix recommended a sealed 1.5ft for sq, or a 3.5ft ported w two 4x9.75in ports. Are these still the best choices? Those were speced for car use and that was a long time ago. I have bassbox pro 6 and cant figure it out. Everybody says go low for home theater and I'm stumped. Anybody up for a little bench racing? Specs are:
Fs: 26.21HZ
Re: 1.75 Ohms
Qms: 9.26
Qes: 0.594
Qts: 0.558
Vas: 114.63 liters
Mms: 283.15 grams
Cms: 130uM/Newton
BL: 10.89 Telsa-m
SPL(1w/1m): 88 db
Sd: 792 sq cm
Xmax(field): 36.2mm p-p
Size of enclosure is dosent matter, its in my living room. I want low, right? My front mains go to 65hz, receiver is Yamaha with YPAO room eq, room is 15 by 20 or so with 12ft ceilings and hardwood floors. Use will be 95% movies, 5% metal. Anybody feeling like helping out?:huh: Thank yall in advance, Jeff.
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Welcome to the Home Theater Shack, glad to have you with us!

Are the subs single 2 ohm or dual 2ohm?
They are dual 2ohm. Was only planning on using one sub. Thinking I should keep the other for back-up.
Awesome!! And thank you for responding so quickly.
The Phoenix recommended box sizes are for a car application which gets an extreme amount of cabin gain to boost the low end. A home interment doesn't get anywhere near that much gain so the box needs to be bigger to get the low end bass.

The driver/amp combo models well in 10 cu.ft. (net volume) tuned to 18 hz. Porting will require two 4" flared ports 17" long each. Modeling shows 104 db at 17 hz without any room gain you may get.

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Thank you very much! I must admit I wasnt expecting a box that big. Bet you've heard that before!This build will test the bounds of WAF, but I test this regularly, LOL...Guess this box will have to be the base of my DIY entertainment center. Recommend any threads that would provide guidance on my journey through a build of this size?
It doesn't have to be 10 cu.ft., 6 cu.ft. would be the size of a 24" cube. You can make it whatever you're comfortable with.

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Nope, I dont want to leave anything on the table and wonder what I was missing. Will the sub have a decent life expectancy in this set up? High excursion related fatigue? The reason I ask, I may get itchy and dig out the "back up" driver. I heard this "give me more" syndrome is common..LOL.
When I get of work I'll post a graph of what the sub is capable of. Any idea what the power handling is?
550W RMS / 800W Peak Power Handling-- is what I found on the net here at work. I have the actual box insert at home. I could scan and post if it would help. Are you talking about a graph of different info than the one you modeled last night?
550 RMS is what I need, thanks. The graph I'll post will be of the SPL, with a Bash 300 the sub is nowhere near it's capabilities. Driver related fatigue won't be an issue with 300 watts.
Yes, I'm thinking of trading it in for that Behringer EUROPOWER EPQ1200 (2 x 600 Watts into 4 Ohms) and only running one side till I get the itch for the other sub. Does the amount of power I throw at the sub change the recommended enclosure?
But please continue any efforts basing on the Bash for now. Wife is watching my spending. I'll have to sneak up on the Berri.
With a pro amp you'll need a subsonic filter for a ported design, either a iNuke DSP or a subsonic add on unit for a pro amp that does't have a subsonic filter. ( also known as a hi pass filter or HPF)
Ok. That's like the new write up at partsexpress on the Double Trouble sub build. Your take on this approach? Going the pro amp route vs. plate amps...For a noob like me?

The Double Trouble is a sealed design and a HPF is not required. For your ported design you will need one to protect the driver from over excursion below the tuning frequency.

As for the graph, yellow is with the Bash 300 amp, green is with a 1000 watt amp that has a HPF in the 18 - 20 hz range. The gain in SPL is 4-5 db and the cone excursion is still under its rated Xmax.

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On paper that dosent look like like much, but in reality thats a big deal. nearly like adding a second sub. +6 db for an identically powered second sub, right?
Hope you're still with me Mike. You said 10 cu ft "net volume". If I understand correctly, that means 10 ft plus .2ft for the driver, and how much for the ports and bracing? Thank you again for all your help!
For porting and bracing volumes and help for making your own cabinet design, go here:


For ideas on a cabinet design click on the Database link in my signature.

If you have any questions on anything, just ask. That's what we're here for. :T
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