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I just set up an Atmos 7.2 surround system (in-wall/ceiling Monoprice Alpha) in my great room (25x21 w/ 8' ceilings). Right now I have 2 Polk PSW108's, running off my Onkyo 676, that my wife purchased for me on Black Friday. The Atmos is GREAT but I have no low end, the Polks just can't keep up. After looking around at powered subwoofers (I really like the Monoprice Monolith 10/12) I think I have convinced myself to attempt a DIY build. Since the 10" Monolith starts at 499.99 plus shipping and the 12" is 799.99, Id like to keep the build under $500; I was looking into the Dayton Ultimax 12" in a vented enclosure running off a 500w plate amp (1000w would put me over budget). However, I just came across an almost new pair of Infinity Perfect 10.1 (car subwoofer) for $100.00, which I would run off of two 300w plate amplifiers (at $115.00 ea. or 500 watt for 180 ea.), also vented, keeping me well under budget. My main objective is Home Theater with 80% use being movies so I would like to be in the area of 20-30hz with reasonable volume. I am no professional when it comes to home audio nor am I an Audiophile, I am just looking for the best bang for my buck that will enhance my movie experience. I do not have the Wife for an 18" subwoofer, and I would be hard pressed to convince her into a 15". Out of these two choices what do you think my best option would be? Is there other options that would keep me under my budget and yet allow me to obtain my goal.

*I like the idea of "powered" subwoofers for room placement/mobility/options. I looked into the power amps (Behringer nx1000d/ Crown XLS1002) but then the sub would be confined to my electronic closet, which is behind the main listening area by approximately 15', not ideal I don't think.*

Thanks for any input.

PS. My carpentry skills are above par.
 

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If it was me I would go with the Ultimax over the Infinity's, but given the price difference between I would get the 15" UM.... at $224.90 it would be a way better then two 10's at 200.00. Well worth the extra $24.90 and will provide you way more output in the LFE range you note your missing. Power wise 500 watts should work well, if you can afford more power always a must at AVS =)

Edit: The difference between a 12" Vs 15" would be minimal in appearance but the performance would be a lot better as related to the wife if done in the right box.
 

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A room that size is gonna need 2-4 18's to feel the bass, and correspondingly, more budget.

What about two false coffee tables hiding a slot 18, say downfiring?

With one of these you can drive several hundred feet of mic cable, which doesn't cost much:
https://www.parts-express.com/art-cleanboxpro-stereo-balanced-unbalanced-converter--245-868
https://www.parts-express.com/talent-vcm18-xlr-male-to-xlr-female-microphone-cable-18-ft--240-9480
https://www.monoprice.com/product?p_id=5346

2 of these: https://www.parts-express.com/neutrik-nl4mpr-speakon-connector-4-pole-round-chassis-mount--092-054
4 of these https://www.parts-express.com/neutrik-nl4fc-speakon-connector-4-pole-cable-mount--092-050
1 or 2 of these: https://www.parts-express.com/250-ft-black-14-awg-2c-outdoor-uv-resistant-direct-burial-speaker-cable--102-305

and then you can put this in an HVAC room, attic, crawl space, or broom closet:
https://www.sweetwater.com/store/detail/NX6000D--behringer-nx6000d-power-amplifier-with-dsp

Alternatively, you could put it behind a neo magnetically attached door that vents out the back of the coffee table and just run 1 speakon between the boxes. The other having a power cord for the amp. The amp has fans though.

Otherwise just go with 2 plate amps, plate amps aren't as powerful and are missing the DSP loudspeaker management software in most cases...

2 10's or 12's just isn't gonna cut it. I'd hate for you to spend $500 on subs, and still need more...
That's just the physics of it: human ears are inefficient at hearing bass, subwoofers are inefficient at making bass, and big rooms get exponentially more expensive to have enough PSI/SPL at all, let alone at a distance.
Not a good combo to have, but it is what it is.

You lose 10db in the first 10ft, and another 6db in the next 10ft.
Going from a 1000cuft room to a 4000cuft room is gonna drop the PSI to 1/4th of it's previous value with the same gear.

That's why boomer cars are sooo loud, they only got 40cuft of air in them to pressurize, when the wave hits the car panels it reflects back inward in a short distance, adding even more SPL, upwards of 40db of free bass.

The whole surface of the car is then radiating the bass at this high SPL, which is why they can knock pictures off your house walls from 100ft away with a 12 and 100watts, yet a large HT sub with 1kW can't... concrete/drywall/OSB and 2x8/2x4's don't flex like sheet-metal/plastic on springs do.

One 12 & 0.5kW in a car might hit 135db, but in a 4000cuft room you'd need like 8 18's & 8kW to hit 135db safely, or whatever.
 

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Im with BassThatHz, Hes a genius :) 10s wont do diddly squat. You can DIY so much cheaper. Even the VBSS thread you can build 18" VBSS into even night stands and shake your eyeballs loose.



To make sure i had plenty of Bass and ULF i built 5 towers with dual 8" each with a F3 28HZ and dual VBSS subwoofers. Our small room is 10-12'W 17'L 8' ceiling and i would say its sufficient bass. But i dont need to ask permission :)
 

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I'd try and get to an 18" driver over a 10/12, personally. Your budget seems to be a bit difficult as far as DIY goes, as when you consider the cost of the amp, you are cutting it close for your 'great value' sweet spot for DIY. Another thing to consider... the physical size difference between a 10/12 and 18 may seem to be huge, but when you look at the enclosure you will be tossing either the 12s or 18s in, the difference in terms of overall size isn't as dramatic unless you want a big ol low tuned box

Do a quick search on Marty Sub and VBSS. Both are ported enclosures that are well proven performers, and allow easy modification to match your room requirements.

The Marty subs are a 'full suite' of sizes, which will all perform a lot better than the 10/12s you were looking at, and are reasonably small. If your carpentry skills are decent, you can make them into an end table, coffee table, etc, without too much work... but may be pushing the budget in the end if you are using anything more expensive than MDF. The VBSS is a smaller unit that uses a nice cheap driver (PA460) and is very efficient. I'm not sure what a behringer NX1000 w/dsp (they were just switched from the inukes to the NX line) run anymore, but I think a pair of VBSS and a NX1000dsp or 3000dsp would come in a hair over your budget... but be substantially better for you performance wise than a 10/12.

I'm sorta with the above... I think you'll be a bit disappointed with a 10/12", and you don't save much cash DIY wise when compared to an 18" setup. You could go sealed, which may be a bit smaller than the marty options or VBSS, but you'll be down a decent bit of output for your money.

I don't have a strong opinion on a 'powered sub' vs a standalone power amp, but I would personally vote for a separate power amp. It gives you a lot of flexibility as far as placement goes... and any upgrades down the road you may want to do.

Given your criteria, I'd vote for a pair of VBSS and an NX3000dsp. Pretty sure it will come in a bit above your budget, but it will be fairly close in the end, I think. I'm not positive whether or not you can power a single VBSS with a single channel of the 3000 (with the amp limiter set pretty low, for sure), but using a 3000dsp could give you independent DSP for each sub for now... and down the road if you want to add on you could move both of your VBSS subs close to each other, EQ them as one sub on one channel of the amp, and then utilize the other channel of the 3000 for whatever you want. If I recall, the NX1000 is only a little cheaper than the NX3000, hence my recommendation on that end.
 

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If you model the 15" Vs 18" given the WAF you will see they are close to similar in results. Not huge savings between the 15 and 18 but its so close to the 2 12's in price you are better off with the single 15 for LFE
 

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Discussion Starter #7
The 10's were $100 for both. Im more inclined to do plate amplifiers and have "powered" subwoofers because I can place them anywhere around my room where there is an outlet on the wall/floor using one of the Rocketfish wireless subwoofer transmitters. If I go with a pro-amp, the sub(s) would be imprisoned in the audio closet in the rear right hand side of the room. No cables can be ran through the floor or around the room...Wife's rules. Persuaded her to do a single 15, maybe two.

My old Captain used to tell me; "It is easier to ask for forgiveness than ask permission."....Didn't work out too well, ha.
 
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