Rel Does Not Recomment Isolation Stands

REL is wrong plain and simple, They will put 12 coats of lacquer but won't cop for a set of 10.00 springs in bulk... Cracks me up.. BLING and glitter sells. What actually works you have to train people about.. Nothing changes..

I like both or course, Bling and Springs.. LOL

As far as raising the speaker yes it can be an issue, I'm actually dealing with a tweeter that use to burn a hole in you. By raising the speaker 1" and turning the tweeter 90 degrees, I was amazed.. Things just worked.. 

Engineer, NO! Mechanic YES..

Regards

jtcf, some subs like the REL bottom firing units can really rock the joint. I use to really like it, but things change. That's one, I don't drink so cranking the system is usually an occasion but not the norm.

Raising a bass unit UP is one of the thing REL does rather nicely. The BOTTOM sub just need a butt plate or slot load it and use and air bag to decouple. Stack 2,3,4 high, ALL are decoupled because the bottom one was. I like that idea..:-)

Regards

SVS, JL and the RELs S812 (I think) it's not ported are pretty serious subs..

I still believe more is better and medium excursion is better if you have enough drivers.. It's about moving air. HOW you do it, makes a big difference..

In the 80-90s I ran 4 Tall Boys. They were a 12", 15" and 15" passive in a 6cf Tall box. 1000 watt Daytons is what Brian recommended at the time. The passives were tuned to your room, amps and speakers with pinching putty from the passive to adjust (Q) uality. Thumb nail at a time.. Very accurate way to tune and blend a bass system.

OB Servo subs, both sides of the driver are loading and onloading the room, your ears act different.. I use 6 12" OB high excursion drivers... they work both ways not one.. Decoupling those cabinets made a heck of a difference. They are made to stack too. I ordered 2 more double 12", we'll see.

Regards

The last part of my career was foundational drilling for earth reinforcement. I don’t care what you have it moves and vibrates. Even 7.5" concrete on 8" friction peers every 4 feet vibrates.. Decouple everything.. Simple. There no exception to the rules. Ask any mechanical or civil engineer, isolate and eliminate where possible.

Check this out there is an overpass that was built, it vibrated so bad when a train went under the overpass for a 1/4 mile in every direction everyone was complaining. They had to go down 160 feet to bed rock and anchor with several strands of wire rope. 130 8" holes 160 feet deep they had to hold 50 ton when stressed. That is called coupling.. Spike are a pure illusion that can look OK at best..

Open the hood on your car or PU, see any spikes for engine mounts.. LOL No one who knows about vibration uses spikes.. NO ONE.. Just in the stupid stereo world.

Get an accelerometer and see for your self.. I have a PCE-VT 3800s. It tells the WHOLE story about vibration.. You can’t argue with the science.. sorry.

Thing vibrate..

BTW it's time to feed the chickens..

Regards

Full disclosure, I'm not hobbyists. I've produced subs, bass bins and horn loaded bass enclosures for over 45 years.. I've sold, traded and modified all kind of others manufactures price point builds.. There are FEW that come close to my crazy collection of designs. Not EVERY sub is for every situation..

Bottom firing SUB are kids stuff plain and simple.. I don't mean to hurt anyone feelings. The KIDS are even decoupling their bass enclosures in their cars. Mass loaded with springs on the top and bottom..

You cannot decouple a sub with a bottom firing driver if it is just hanging there. Without a butt plate or being in a slot, the floor is going to be a huge out of time passive radiator and the FIRST reflection point for the subs.

I didn't make the rules I just work with them and not try to defy what you cannot change. Everything vibrates no exception to the rule.
Direct the pressure away from the floor and decouple the drivers from the rooms surfaces.. IF any manufacture has a better idea I'm all ears..

If you want to make smooth even bass understand boundaries but the right ones, the walls more so than any. Different size or different distances from the wall vs the driver location.

Regards