A bench style cabinet subwoofer 2x15 closed

[Juhazi]

Norman, yep the 100cm deep cabinet. I'm not at home now but I did a simulation without rear chamber effects too, but only in one direction. This backwave makes huge effect to phase, it disturbes me even more than spl hump.

Hornresp is really pain in the @ss because it reveals box problems. I intend to put an IKEA summer matrass worth of stuffin in the box, I hope that helps a bit.

[norman bates]

my buddy who builds ppsl said he's measured them and they do not have the peaking in the response from the hornresponse simulation.

Instead look up ppsl on audioasylum. Less Hudson. Others who had heard his ppsl loved the sound.

None of my subs have had stuffing.

Norman

[Juhazi]

Some more clarification of Hornresp graphs. I did several iteration using differnent values for the throat segment (plenum in this case) The depth of the plenum determines the frequency of "hump", the area of plenum it's magnitude and sloit loading effect.

If the L12 is set to 20cm, the hump moves to 320Hz. and phase shift from 80 to 90Hz.

Here is what Hornresp gives to conventional closed box, no plenum, chamber reflection masked/not masked

[Juhazi]

I played a little with www.hunecke.de Loudspeaker Calculator to find the position for second sub and to find best listening position and height.

It seems that the position of my new PPSL sub is almost worst possible. Too bad I can't move it. The second sub is on top of the bookshelf at 2m height and in the corner, it helps substantially. Third sub doesn't help any more really. The listening height seems to be very critical, I must keep my ears at 85-90cm (preferably the lower the better). The worst is 115cm.

The best position for a sub is in the middle of the room or on the long side near wall.

[norman bates]

what ?????????

keep your simulations, I'll keep my ears.

yes room modes are a tremendous pain. Just sit where you want and move sub till you like how it sounds then reverse the 2, or keep a sub (ideally somewhere between the front speakers) then move around till it sounds good and you sit there. I find front 1/2 of room ok, then 3/4 back there is no bass, then more as you get to rear wall. And how high matters 2. I like the sound of my dual 15's (as a sub) standing up versus laying on the ground.

Room modes are a pain in the ............

It doesn't have to measure flat for you to enjoy it.

Norman

[Soundtrackmixer]

Originally Posted by Rojoh

I vote "yes" to your sealed wooferbench-idea. Camouflaged as furniture it blends well into the room. Here's what i did with 4x10" Seas woofers/sealed. Nice, well balanced bass.

Now this is way cool!

[TMHutson]

Norman, have you tried the technique of putting the sub in the position where you are going to listen (on the chair or couch), then walking around and listening for the hot spots? I am going to try that tomorrow. It's too late right now to play bass I may also have to coerce someone into helping me by sitting in listening position (I will be nice, and not ask them to move the sub around) while I move the sub around.
I am going to test with small 8" sub that is easy to hold and move around. With extension cord and high quality 12' car audio RCA cable...
I have limited places I can put the sub. Although there is a huge couch that is not being used, and needs to be raised for easier seating... hmmmm. Sub couch? TL maybe?

I have plans for multiple sub ala Gedde's. I have several salvaged sub amps, and plenty of car subs laying around :/ But nothing built at the moment... Just the small 8 (which I hate)...

I am watching this thread to see what OP Juhazi does, to see what I can learn.
I am curious to see if using the room mode calculator translates well for you as you move sub accordingly...

My sub(s) are for stereo listening only. Some movies, but not important. I can do surround, but don't care. I am over it...

[norman bates]

nope, but I notice many dead zones (no bass) in my room. I sit where the bass is (front 1/2 of room).

[Juhazi]

TMHutson, the way you are testing is a very good and practical procedure.

I've done these many different simulations because I still have to wait for the drivers and I simply can't do any measurements!

My bench sub is so huge that I have no other option for placement. I'm asking for trouble! I just checked that I'd have to cut both my now finished cabinets by 15cm to fit the long side of my room (left seen from listening sofa) The right side is covered with a bookshelf. Well, I could tear it and put my bench sub partially under it... But then the whole room needs rethinking.

Simulations and measurements apply only to one spot. My AVreceiver has Audyssey2 and it uses 3 measurements. I think I'll connect both subs psotiioned as simulated above and let Audyssey do EQ. Then I'll listen to it and make some REW measurements.

But the difficult part is that I'd like to use the sub also with my 2-channel amp, without speaker management. Then my main spekers will get full signal and sub(s) a mono signal lowpassed by the Hypex plate-amp and it's simple EQ. Then I can only move my sofa for the best sound.

Room simulation was inspired by discussions at a Finnish audio forum

[tb46]

Hi Juhazi,

Post #59: "...My bench sub is so huge that I have no other option for placement..."

How much trouble would it be to move one of the woofer to the end of the bench (corner), and leave the other woofer where it is? That way you'd have two sealed subs, one exciting the room in the middle of the wall, and the other one in a corner. That would change things. Naturally, you'd loose the PPSL function.

Regards,