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subwoofer with zero punch... help

I'm a noob go easy but give me the technicals(if any) because I want to learn. I was very excited to get that extra grunt and some good punch from kick drums out of my new subwoofer when it arrived.  I was severely disappointed when I plugged it in.  It only sounds bloated and boomy and there is ZERO amount of punch or slam to speak of.  And I do mean zero! I've had 6in car speakers that "hit" harder than this thing.  It'll shake everything like crazy but there is no definition to any of it. I need help diagnosing where my issue is because I don't think its the sub itself. lol

Sub: SVS SB-4000
Speakers: Klipsch RP-600M (these sounded great on their own)
Amp: ~90s JVC 70w/channel home theater amp 
input: ~$100 headphone DAC and playback from TIDAL
Room: concrete floor basement 26ft x 14ft x 7ft drop ceiling with R19 in the floor joists, full cover thin carpet, lots of furniture and a decent amount of cheap sound absorption foam. 

Other Notes about setup:
1.Sub signal is RCA out of headphone jack, I know its not ideal but splitting rca out of my DAC was worse
2.This is temporary residence, I plan to move but I want to know what my problem is before I bring my issues with me to a new listening space. 
3. The acoustic foam was an attempt to kill the drone from a crypto mining rig which it was successful in accomplishing.

What I tried so far: Tuned the eq for the sub with a tone generator. Found that 65hz was nearly silent, I boosted that and bumped the LPF to 75hz (12db slope). I also tried various boosts and cuts between 65 and 140hz on the whole system but everything sounded worse.  For reference I have 4in woofer monitors at my desk with a little Polk 8 in woofer and it "punches" harder than the SVS 4000.  Like the title says.... Help...
ctstauffer
ctstauffer OP
2 posts
 
Thanks everyone! You were kinder than i expected, to be honest, given the blatantly wrong ideas I held.

 Clap test is real dead isn’t it
Yeah its pretty dead.  its a very dead room overall.  So it appears there were several things at play here which I kind of expected. Here is a summary of what I have taken away so far.

1. The LDF drop ceiling and R19 is creating an enormous bass trap that is sucking the life out of the woofer.  And too large of a room.
2. I have been using and understanding subwoofers wrong my entire life. Always pushing the LPF too high to add punch up at higher frequencies than it was designed to do.  Punch/ kick ~(70hz-140hz)  needs to come from 6 to 8 in woofers in large cabinets with ample power to run them.  My bookshelf speakers will never suffice and will always leave a gap/dip between them 
3. non ideal sub out signal.(I already knew this but its good to have confirmation)

further questions:
What would be an okay room? I may be building a home in the near-ish future and would have my choice for size and layout.  Mainly i'm looking for rough dimensions. Ill do research on what treatment to put in it, and how to construct it.
I am very lost when it comes to amplifier brands. I know and like the lower end Schiit offerings but idk where to look for comparable equipment.

gdnrbob
4,444 posts
 
@OP, 

I think you should do some Googling on audio room design.
There have been more than a few threads here on Audiogon on that subject, as well.
I would also suggest going to as many dealers as possible. Audition as much equipment as you can. Get a feel for what you want/like.
Make a budget (that you will probably max out) and get the system of your dreams.
Though well intentioned, some of the information you might gather here should be taken with a grain of salt.
My 2 cents...
B

PS- If you are building a new home, don't forget about the landscape.
terry9
2,333 posts
 
The science was done at the University of Salford, School of Acoustics. The noted Cox teaches and researches there. Spoiler alert: it's not snake oil, like most of what you read.

Mechanics of build is available in several places. Absolute Sound (IIRC) about two years ago, and manufacturer's websites are good. Go for the real goods from industrial suppliers like Pabco, which IIRC, manufactures Quietrock. I use Quietrock 545, and recommend it enthusiastically. Great company too. 
terry9
2,333 posts
 
Should have mentioned elastomeric glue and caulk. Chemlink makes great products, I used 10-15 cases of the stuff.
terry9
2,333 posts
 
For amps, I build my own for the most part. But when I want clean, good sounding, bullet proof power at a reasonable cost, I always use Bryston.

Check out their factory rebuilds by calling them. I emailed them about a month ago on Sunday. The VP responded Monday morning. I phoned him that same morning.Then I bought a factory reconditioned unit that afternoon, with an additional 5 YEAR WARRANTEE. At a reasonable price.
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