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audiophile2000
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Subwoofer Question

I recently moved into a new room and despite a decent bit of work with acoustic panels am still have some issue with sub placement, i already have bass traps around the room and it has improved but not solved the issue.

I have the PSB Synchrony Ones for the main speakers and they actually go decently low so I question the need for the sub but would still like to hit the very low notes cleanly. The problem I'm running into is the sub seems to be bloating the music. I know from my previous setup that this is 100% a room issue so trying to think of solutions.

The sub is a REL G1 so and I have used the same setup in a previous room and it worked perfectly, but in this room I'm still running into issues blending it with the system. I even have it set to cross over a 25hz and it still seems to be sticking out and not coupling with the system properly.

So interesting thought came into my head about adding a second sub (another REL G1) to the room so there was one for each speaker. I'm curious if anyone has done this and seen it solve an issue like mine. Basically the issue is bass seems to be building up in the room despite heavy acoustic treatment. I'm curious if adding a second sub would smooth everything out and reduce this buildup or if I would just be compounding the bass issues i already have. Room is roughly 13 by 10 so I know one of these subs is already overkill. Really not trying to get more output just a more even pressure buildup/reduce decay times with the bass.

Bill B
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sub

If the bass is now bloating/sticking out/building up as you say, adding another sub is probably not the answer. It would take a miracle for a second sub to cancel out all the problematic bass from sub #1 while contributing its own bass.
When I've set up a subwoofer, it has been helpful to have a cd w/ test tones and a decibel meter. I know some current subs and receivers supply their own, but I haven't used those models. Anyway, charting the response on the SPL meter supplemented my by-the-ear settings very helpfully. Although you have already set a low crossover frequency, which is good, there may still be some adjusting to do, as well as repositioning the sub. Get it out of the corner, if it is there now. Follow the manual and make sure you are adjusting the PHASE properly, in addition to crossover frequency. Putting the sub on the front wall where your speakers are, and even with your speakers (not behind or in front of them) can be helpful. REL or your dealer can help advise, too.

gasolin
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A second sub could be an

A second sub could be an acousticaly advantage if placed right i have heard that it's surpose to be the opposite corner, not to the left or the corner infront of the speaker, but the last corner across the room.

Try some sonic design feet or mabye deflex superpods feet if you can find them.

Some subwoofer like welodyne kan aut be adjusted, so if it's not the bass from yor main speaker that's the reason for your bass problems you might want to consider a subwoofer like that.

This could also be usefull for you (there are video's of the effect on youtube)http://www.dspeaker.com/en/products/anti-mode-8033.shtml

The isoacoustics stands are good, since you only need one you don't pay so much about 120€ (don't know what the price is outside of europe).

Mabye bass traps

audiophile2000
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Thanks Guys

I tried moving the sub to the other side of the room and that seemed to help a bit. I think part of the issue is the room itself and also that the main speakers are actually extending pretty low.

In terms of acoustic treatment, really nowhere for me to go on that side. Already have bass traps in all corners, and also in the front and back.

Recently ordered the XTZ Room Analyzer kit so i'll report back when that arrives and see if that helps fine tune the room setup.

Bill - Just curious if you had a similar issue and tried to go from 1 to 2 subs. I had two subs on a previous system and it did round out the bass, but i also needed the extra output. TBH I really probably need a smaller sub for this room as the G1 is massive so I'm already overloading the room with the sub gain essentially turned all the way to the bottom so I was viewing this option as a hail merry approach, which seems to be your take on it. Was curious if you ever ran into this issue in practice though

Also with my current gear (sim audio front end) and REL there are no DSP room correction options, but from what i've read they can sometimes produce more problems and can really only be used to fine tune a room after proper treatment. My HT side of the equation has all the DSP and bass management curves but i normally run it in Pure Direct as the equalizers normally sound worse in most cases (in my opinion).

gasolin
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Only if you add a second sub

Only if you add a second sub you should place it in the opposite corner.(don't know where the bass should point at,the left or right corner)

Try to hear if you can hear any difference https://www.youtube.com/watchv=UuyXw50q5Jo&index=4&list=RDSI3ujXuG4uE

https://www.youtube.com/watch?v=LvOjMbrJwDY (music starts about 2.02 min)

audiophile2000
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Speaker Stand

Was thinking of trying to raise it off the floor to see if that did anything as I have my main speakers on plinths, but the big issue is the REL G1 is it is a 100 pound sub and has a very large cabinet so haven't found anything but custom made products that could support its size and weight.

wkhanna
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Two for the Show.....

I use two. I had lots of issues when just using one.
Maybe this can help?

http://www.audioholics.com/home-theater-connection/crawling-for-bass-sub...

audiophile2000
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wkhanna

would you mind expanding on the issues you had and how a second sub corrected it.

commsysman
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Subwoofer

IMO getting a second sub is not the answer to the problem; nat at all.

The simple fact is that most subs do not produce good clean bass with no resonant points, due to their basic design.

I find that my NHT B12D is outstanding in this respect, due to its sealed acoustic-suspension design and high-power amplifier.

The acoustic-suspension design loads the subwoofer in a way that tends to eliminate resonances and the "bloated" sound that most subwoofers have. It does require more amplifier power, which NHT supplies to do the job.

If clear realistic low bass is what you want, I suggest that you look at this one.

wkhanna
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Time for some splaning, Lucy......
audiophile2000 wrote:

would you mind expanding on the issues you had and how a second sub corrected it.

A single sub in the typical room will create nodes, areas were certain frequencies are cancelled by reflected waves. Using two subs will help create a more even spectrum in the room.

I had a huge suck-out in the 45 to 60 hertz range with or without a sub. It was easily revealed by simply running frequency sweeps and using a Radio Shack dB meter. Plotting the readings showed it was prevalent regardless of sub location. Once I added the second sub, the plot was Much flatter.

I currently run my subs via the second set of stereo outputs from my pre-amp and have them situated next to the respective left & right main speakers. Clarity, image focus & above all, frequency response are now V good in the lower range.

It is often said the frequency range below around 70 hertz or so is no-directional (you can not identify the location of the sound).....

You would be quite surprised how much low-end imaging is available when subs are set up this way if you are not running true full-range speakers.

I will try to find my plots & post them for you.

Bill - on the Hill
Practicing Curmudgeon & Audio Snob
- just an “ON” switch, Please -

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