Looking to build 2x18" enclosure - PPSL?

[woody]

I was in an apartment once and on the second floor. From my apartment to the basement floor was 16 feet, and about 36 feet from the front wall of my apartment to the back wall.
All in all just about perfect for a 16hz standing wave. When I played organ music it would often really become an moving experience !

 

[MemX]

haha How cool



Another quick update from me!


The guy building them has now finished one, having oak veneered it and then done a few different layers of stain on top to darken them down to match my existing furniture.

It was mid-20s (degrees C) over the weekend at certain points, and it was apparently a very sweaty affair getting them fitted due to the hassle in piloting holes and getting the drivers screwed in securely at the back of the slot!

I'm just glad I never tried to build them myself - my DIY is poor at the best of times... lol

Hats off to my builder chap, I am very thankful for his hard work and care with the details!

 

[NEO Dan]

Soo is it live, or is it MemX?

You get your eviction notice yet??

 

[MemX]

lol I see what you did there

It's still 3 hours drive away from mine, I need to hire a van to pick it up as it will never go in the car! Once it's out the way he can finish the second one

I need to measure up cable lengths and drill some holes at this end in the meantime - the CV5000 amp is ridiculous for fan noise and I'm reluctant to fan-mod it as I know my luck (it'd probably fail!) so it is going in an adjacent cupboard and the cables coming through the wall!

We can hopefully measure one before I take it away as I'm not yet setup for measuring

 

[CLS]

It's sealed, or the vent is somewhere else (not in the photos)?

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BTW, in 20-some degree C, it should be very comfortable.

It's 35 here and we need powerful air conditioning to get the temperature you have.

 

[xrk971]

It's sealed, or the vent is somewhere else (not in the photos)?

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BTW, in 20-some degree C, it should be very comfortable.

It's 35 here and we need powerful air conditioning to get the temperature you have.

I was asking myself the same question and one of the photos

makes it appear to be a sealed box. Should be interesting what the PP slot loaded port does to a sealed alignment. Maybe +2dB boost overall and -5dB reduction in 2nd order HD? Kind of a +7dB boost from standpoint of SNR

 

[djk]

I recommended he run a sealed alignment for his PPSL (for this driver).

 

[MemX]

Hi all!

It is indeed sealed, with each pair of drivers in a total of 7.5 cu ft internal volume.

I've not actually heard a PPSL subwoofer yet so I hope I like it!



re: the heat, it is always very humid over here, even in the mid-20s, so it always feels a lot hotter! We have 29 degrees later this week, it is not going to be pleasant...

 

[norman bates]

5db reduction in 2nd order harmonic distortion ?

try 25db of distortion reduction.
Instantly audible is the difference.

PiSpeakers Forum - Push-pull versus shorting rings - Wayne Parham, June 21, 2006 at 16:18:33


Norman

 

[MemX]

Thanks, Norman

I have seen a load of graphs illustrating reductions at different frequencies, but I can't remember where I saw them now!

 

[norman bates]

Are you boosting the low end ?

based on databass website, their 4.2ft3, 107db@100hz, they bump up a bit 40-50hz (109.5db), 3db down from the bump (106.5db @32hz).

100db@20hz, add 6db for 2 drivers for 106db@20hz................

Data-Bass

I'm not sure you'd need boosting.

Much, much better than the chase 18...........

 

[norman bates]

 

[MemX]

TBH I'm not sure what boost they will need! From what I've read, Room Gain generally begins as you drop down past 30Hz so I am hopeful that it will pick up where the subs naturally start to roll off. My room is also pretty solid (concrete block under plasterboard, concrete skim over floor joists, double glazing) so that should help, and my AVR has Audyssey XT32 to help tame any peaks (although I don't think it boosts).

If I do need to boost, I'll look at a Bassis, MiniDSP or AntiMode, I reckon.

 

[MemX]

Right then, it's been ages so time for an update!

My box builder guy is a gent and a legend - despite being a lot more work than he had planned (and quoted for!) he delivered great quality with a real pride in his work, so I am very happy with the end result, both aesthetically and aurally and I recommend him to anyone!

I love the sound of them, they sound clean and miles away from the 'fat' or 'bloated' sound that can sometimes affect subs that aren't quite 'right' (they are night and day 'tighter' than the SVS ported sub I was using previously) and I literally can't stop listening to them. The first thing I do when I get in the door after work is turn everything on and get some music playing! I wasn't listening to much music with the SVS but these have got me listening to all sorts of new stuff, including Classical music, which I've never really been bothered with before, but they still have all the depth required for movies!

I've still not managed to get them fully EQd but am getting there slowly. REW is being a PITA but with the help of another kind forumite I am hopefully on the right path now and it shouldn't be long...


I've attached some pictures below so you can see the end product - it's not small, I will admit that, as they are around 11cuft each, if my calculations are correct, so 22cuft in total, but they make good use of the alcove in my room (exactly as planned) and as they are in two enclosures, if/when I move I can either stack them again or split them across the room to smooth the overall response curve if I need to.

At some point I'd like to build a couple more and put them in a dedicated Cinema room, but that will have to wait!

Thanks for everyone's help on here, both in this thread and with all the helpful info posted all over the board - I'm glad I went with PPSL and recommend it to anyone looking to DIY

 

[djk]

"I love the sound of them, they sound clean and miles away from the 'fat' or 'bloated' sound that can sometimes affect subs that aren't quite 'right' (they are night and day 'tighter' than the SVS ported sub I was using previously) and I literally can't stop listening to them."

Hey, hey, hey, another addicted-to-clean-bass junkie!

 

[sumaudioguy]

I long ago gave up big drivers in favor of several smaller ones. Four ten inch drivers is the same area as an 18 without the floppy cone effect or the need for really large solid boxes. A good ten with go in a small box which is easy to build or as in your case, two small boxes still far easier to build than one big heavy solid box of any type.

 

[mordikai]

I long ago gave up big drivers in favor of several smaller ones. Four ten inch drivers is the same area as an 18 without the floppy cone effect or the need for really large solid boxes. A good ten with go in a small box which is easy to build or as in your case, two small boxes still far easier to build than one big heavy solid box of any type.

Whatever.

 

[mordikai]

memx super sweet!!

 

[djk]

"or the need for really large solid boxes"

Small box = low efficiency.

http://i959.photobucket.com/albums/ae76/fullrangebates/pudhpullsubquad12_zpsb771020a.jpg

Four Dayton 295-120 have more output above 20hz than two of the SI 18, and cost less (when on sale).

 

[scholl]

These look interesting:

HT18 18″ Subwoofer | Stereo Integrity