Rel Does Not Recomment Isolation Stands

This doesnt surprise me one bit. In just about every situation, especially involving speakers, it is a question of what is be done with the energy. At first glance it would seem to me that you should drain this energy, but some disagree. 

Lifting speakers off the floor, subs or floorstanders, will alter the frequency response as heard at the listening position. I think of this whenever I read a post where in someone praises the practice of placing things under speakers for isolation, etc, and wonder how much of the change is due merely to the elevation, albeit small yet extant. FWIW.

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

The HSU subs that I have now perform worse when I've experimented with isolating them and raising them up.They seem to be engineered to perform at their best close to the floor and on the feet that come with them.

@oldhvymec

I understand. As I said, I was somewhat shocked when I learned this. From an engineering standpoint, it seems wrong. However, I have had them for 15-20 yrs and they sound great to me. Integrating with the speakers is very easily done too. Once they are setup, they add much more than just deep bass. That said, I’m still thinking of the ramifications of this " Controlled Rattle" system of integration.

I’ll probably file this along with the cables which also make a difference despite but don’t measure good

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

"Even though I am NOT electronics engineer I think this is an interesting subjet..."

Since we're dealing with what sounds "good"-that alone is debated  endlessly, Engineering white papers docs, graphs, charts etc. only go so far. 

Anything aftermarket, best to just try and decide with your own ears.

Thanks for posting this, @artemus_5. I’m shopping for a sub, and REL was at the top of my list. The sub is going to be on a suspended floor, and any rattle will be unacceptable. I think it likely that I would buy an isolation platform, but if using it means the sub doesn’t perform satisfactorily, then I won’t use a sub. 

Jim

@tablejockey "best to just try and decide with your own ears” Correct, if test is blind (listener does not know which specific cable is used). In 99% opinion-reviews, cables are ranked by “looking good more expensive is better point”  not performance.

That reminds me, I need to order some SVS isolation feet!  Thankfully I don't own any Rel subs, so they should be great with the ones I have.

@jimcrane

I have been running Rel’s for 15-20 yrs. They sound great and integrate extremely well. No worries about performance...unless you isolate them. I wouldn't give up on them

The secret is to keep the crossover point as low as possible. Volume should be just enough to blend with the mains. They make the mains sound even better.

Their advice is about the default, best. I don't know about springs.

But what I do know is that there can be cases when there are room modes which are located between ceiling and floor, and lifting a sub can address that. That would be an exception that I bet REL could accept.

From my own experience REL is in the right here. 

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 think the real issue is what type of floor is present in your listening room, I have a dedicated room with wool carpet over concrete and I can see no reason in this case to do anything other than drain the energy by coupling. 

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

I have 2 S510 subs  that I placed on platforms that I had from previous subs,after watching Rels videos I removed the platforms and placed the new subs on my 100 year old hardwood floors in my mission home..dam if Rel wasn't correct.....So I would never say Rel who is the manufacture and designer is wrong..cheers 

At least you tried it both ways and didn't rely on what others say. 👍

Trust your ears and not the latest trend.

All the best,

Nonoise

@audition__audio

The think the real issue is what type of floor is present in your listening room, I have a dedicated room with wool carpet over concrete and I can see no reason in this case to do anything other than drain the energy by coupling.

+1

same here

Like pretty much everything in life, it depends. 

Clearly, at least according to some, REL is clueless.  😀

What do they say about iso pads like Auralex Subdude as opposed to stands?   Not much elevation there. 

I can think of any number of reasons why you wouldnt want a speaker (sub or not) moving even the tiniest bit in space. What happens to the energy when you put a speaker on springs? Or is it like the Harbeth theory that the energy is drained through the vibration of the cabinet? A theory which to me makes absolutely no sense.

Yeah, a company that does ONE THING, is clueless. Sure.

Artemus_5, thanks for your response. My objective is exactly what you wrote: to “make the mains sound better.” I don’t want a sub to provide more bass per se. I’ll likely bring a REL home to see if it can live on my hardwood floors without rattling the joint.

Mapman, you ask a good question about the Auralex Subdude, the isolation platform I’ve been considering. I read the REL webpage to which Artemus linked. The Subdude has a depth of 1.75”, I believe. The REL guy said, “When you put it up, call it two inches on an isolation platform. You’re decoupling the sub from the floor and in many instances, it’s exactly the wrong thing to do.”  I don’t know whether or not that .25” difference means that the sub is decoupled from the floor when on a Subdude.

Yeah I would tend to listen to the manufacturer rather than take the advice of hobbyists myself included. There is no one size fits all in this game and the requirements of a speaker are very different than that of a turntable. Take REL's advice. 

While I suppose that REL knows what's best for REL, those theories may not be universally applicable. I have a pair of JL Audio e110 subs up on Isoacoustics pucks. They still shake the floor when they should, but with less boom and overhang. There's no substitute for experimenting. 

Suppose all of REL's employees live in houses and not apartments/condos. 

been with rel subs over the years

that they know what they are doing, and how to very successfully employ their subs, is not worth debating

not to say there aren’t other subs, other methods - i have tried velodyne, hsu, svs, even a wilson benesch... always come back to rel pairs

for high order 2 channel music, they have been, are, and will continue to be my go-to...

There are actually people who dont live in houses?

I knew of a guy who lived in a van down by the river.

No footers or stands on mine and it doesn’t rattle the floor nor the walls. Wood floors on a wood deck 1st floor of a two story house. 

No footers or stands on mine and it doesn’t rattle the floor nor the walls. Wood floors on a wood deck 1st floor of a two story house. 

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

Regarding REL subs what they say for their , or any down firing sub, makes sense.  But not for other subs perhaps?  Re Harbeth, there are two approaches to vibration / energy make something heavy so it doesn't vibrate, make it light so it does.  Harbeth use the later approach.

Ultimately, I think it comes down to personal preference and your home situation.   I don't doubt that REL is correct about isolation.   I actually posted this question to REL support before I was going to purchase the S/812, and found out that it has a down firing driver.   I live in an apartment building and was concerned about vibration and noise transmitting downward.    So I asked about using something like the Auralex SubDude and this was the reply I got:

"We recommend placing the subwoofer directly on the floor and allowing it to couple to the floor. The feet on the subwoofer are specially designed to place the down-firing driver at a specific distance from the floor to achieve optimal effect, and altering this distance by placing the subwoofer on an isolation platform can have a detrimental impact on the performance of the passive radiator. That being said, the front-firing active driver produces far greater output than the down-firing passive radiator, and in our experience if your main loudspeakers are not disturbing your downstairs neighbors then the addition of a carefully setup and tuned subwoofer should not add any extra disturbance."

I ended up purchasing the S/812 and the Auralex SubDude anyway, and have no complain about the performance.   I rather have a peace of mind and enjoy my music and movie then having to constantly worry about whether I am disturbing my downstairs neighbor.  Also not everyone enjoys earth shaking bass, and some prefer isolation to reduce floor rattling.   Just read some of the comments on Amazon on Auralex, and see how many people are happy using one.

Anyway, that's my 2 cents.

Things will vibrate regardless of weight. Worst possible scenario is a speaker with thin walls that vibrates. What do you think the cabinet does when it vibrates? 

"oldhvymec"

I have a pair of REL subs, which I may use in my vacation house, which has a crawl space with suspended floors - which will no doubt vibrate from the REL subs and whatever speakers I use with them - creating "room boom."  

What is the best way to minimize that vibration?