Ditch or save the Feedback Destroyer

berkeley384

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Hi there all

A few years ago Home Cinema Engineering owner (Piers) came to my home and set up a Feedback destroyer to eliminate some excessive boom and help create a more even sound across my primary listening area.

This was set up using my old Denon 3806 with Audyssesy switched off - several adjustments were made and Audyssey was run afterwards.

Move on 5 years and Im now setting up my Onkyo 818 - Ive run the Audyssey XT32 set up wizard - measured in 8 places, and had a listen and i can tell its a tad more boomy at the left side of the room closest to the sub than it is at the right.

My question to you is - do I keep the FD or ditch it. since a nice man with more expensive kit than I have set it up and nothing has changed since in terms of speaker Make / Model / placement etc will having the FD in line have any negative effect, am I limiting / throttling anything by having it in line. Am i limiting the quality of the sub frequencies by having this device in line?

Thanks

Steve
 
As you already have the BFD, and its already programmed, why not just try it and see which you prefer as it will cost you nothing. Logic would suggest that having the BFD in place, and then running Audyssey, should give the same results as before, just improved due to the newer avr being better.
 
As long as you run Adyssey again after fitting it, then I would say you'll be fine. A real FB Destroyer pulls notch filters out, at a very tight bandwidth, so shouldn't affect the overall power of the system, or phase, and the Audyssey will sort that out afterwards anyway.
Best bet is have a listen, refit the FB destroyer, run Audyssey and then re-listen and see if you prefer it. Simple.

Edit - Beaten to it by Geckodan, but at least we agree! lol
 
Hi there all

A few years ago Home Cinema Engineering owner (Piers) came to my home and set up a Feedback destroyer to eliminate some excessive boom and help create a more even sound across my primary listening area.

This was set up using my old Denon 3806 with Audyssesy switched off - several adjustments were made and Audyssey was run afterwards.

Move on 5 years and Im now setting up my Onkyo 818 - Ive run the Audyssey XT32 set up wizard - measured in 8 places, and had a listen and i can tell its a tad more boomy at the left side of the room closest to the sub than it is at the right.

My question to you is - do I keep the FD or ditch it. since a nice man with more expensive kit than I have set it up and nothing has changed since in terms of speaker Make / Model / placement etc will having the FD in line have any negative effect, am I limiting / throttling anything by having it in line. Am i limiting the quality of the sub frequencies by having this device in line?

Thanks

Steve

So have you ran audyssey/xt32 on the new 818 and then put in line the bfd as it was tuned and setup before...........if so how did it sound? if you haven't try doing so.............if audyssey has been implemented as you have stated and it still sounds boomy then its not done the best job as its you who has to listen to it and if it doesn't sound right! its not right.
 
So have you ran audyssey/xt32 on the new 818 and then put in line the bfd as it was tuned and setup before...........if so how did it sound? if you haven't try doing so.............if audyssey has been implemented as you have stated and it still sounds boomy then its not done the best job as its you who has to listen to it and if it doesn't sound right! its not right.


Original Installation of 818 was with FD in connected, then I ran the XT32 wizard - This seemed fine in fairness.

Todays test was to remove it all together and re run XT32. Free up a plug socket and see what XT32 could do :)

Placebo maybe playing its part here - part of me cant believe that it can be right without the FD as no amount of running XT on the 3806 could eliminate the room boom that I had - hence Piers fit the FD and eliminated much (not all) of the issue.

Now I dont know how good XT32 is or what to realistically expect -maybe it can do a better job than a man with 4 mic's and a very expensive machine - maybe it cant?
 
Original Installation of 818 was with FD in connected, then I ran the XT32 wizard - This seemed fine in fairness.

Todays test was to remove it all together and re run XT32. Free up a plug socket and see what XT32 could do :)

Placebo maybe playing its part here - part of me cant believe that it can be right without the FD as no amount of running XT on the 3806 could eliminate the room boom that I had - hence Piers fit the FD and eliminated much (not all) of the issue.

Now I dont know how good XT32 is or what to realistically expect -maybe it can do a better job than a man with 4 mic's and a very expensive machine - maybe it cant?
4 mics and an expensive machine are all well and good, but he's still limited to what a FBD can actually do. If XT32 alone has technology that goes beyond what was previously possible (and it does), then it may well be the case that xt32 will improve your system. That said, all auto eq will do a better job if its properly helped manually before hand, which is what things like the FBD were originally employed for, they where the weapon of choice for people that knew their stuff before good auto eq solutions arrived on the scene at affordable prices.
 
4 mics and an expensive machine are all well and good, but he's still limited to what a FBD can actually do. If XT32 alone has technology that goes beyond what was previously possible (and it does), then it may well be the case that xt32 will improve your system. That said, all auto eq will do a better job if its properly helped manually before hand, which is what things like the FBD were originally employed for, they where the weapon of choice for people that knew their stuff before good auto eq solutions arrived on the scene at affordable prices.

Thank you :) that makes me feel better about leaving it in line - I kinda thought that by leaving it in I might end up missing out on some of the performance that the 818 would give me

Its out at the moment and Ill give it a week or so and add it back in if needs be
 
"quote
Move on 5 years and Im now setting up my Onkyo 818 - Ive run the Audyssey XT32 set up wizard - measured in 8 places, and had a listen and i can tell its a tad more boomy at the left side of the room closest to the sub than it is at the right."

i base my reply on your ears stating "i can tell its a tad boomy" but hey if it now sounds good to you then great.
 
"quote
Move on 5 years and Im now setting up my Onkyo 818 - Ive run the Audyssey XT32 set up wizard - measured in 8 places, and had a listen and i can tell its a tad more boomy at the left side of the room closest to the sub than it is at the right."

i base my reply on your ears stating "i can tell its a tad boomy" but hey if it now sounds good to you then great.

Hi Mojogoes

Its difficult to explain what im trying to say.

At one side of the room, in certain places in can sound boomier than in others - its not "boomy" per say as in its not awfully boomy all the time. By myself with an SPL meter and Audyssey alone I could not cure it. This is why HCE came and configured the BFD. The room has always had that characteristic, in all set ups.

The point I was trying to make and seemingly have done so badly, is that when the BFD is not in line and XT 32 is set up without it - this slight boom or maybe to put it a better way this occasional sensation of directional bass sometimes feels more prominent, this is likely to be placebo i.e my brain being tricked into believing that without the BFT is will be worse and so I perceive it to be that way.

Its not by any stretch bad - most dont notice at all - Im just picky :) So my question stemmed from the idea that if having the BFD in line does not degrade the SQ that would be output otherwise i.e its not going to make sub frequencies quieter or have less punch etc then is there any harm in just leaving it inline ad running XT32

Does that make more sense ?
 
Hi Mojogoes

Its difficult to explain what im trying to say.

At one side of the room, in certain places in can sound boomier than in others - its not "boomy" per say as in its not awfully boomy all the time. By myself with an SPL meter and Audyssey alone I could not cure it. This is why HCE came and configured the BFD. The room has always had that characteristic, in all set ups.

The point I was trying to make and seemingly have done so badly, is that when the BFD is not in line and XT 32 is set up without it - this slight boom or maybe to put it a better way this occasional sensation of directional bass sometimes feels more prominent, this is likely to be placebo i.e my brain being tricked into believing that without the BFT is will be worse and so I perceive it to be that way.

Its not by any stretch bad - most dont notice at all - Im just picky :) So my question stemmed from the idea that if having the BFD in line does not degrade the SQ that would be output otherwise i.e its not going to make sub frequencies quieter or have less punch etc then is there any harm in just leaving it inline ad running XT32

Does that make more sense ?

So to some degree this boomyness is some what the same as before the bfd was placed with in your system..........and when you say on the lefthand or was it the righthand side! i take it that this was in seating positions not just random places with in the room...............to be fair if your hearing a certain annoying frequency it need taming.
 
Hi there all

A few years ago Home Cinema Engineering owner (Piers) came to my home and set up a Feedback destroyer to eliminate some excessive boom and help create a more even sound across my primary listening area.

This was set up using my old Denon 3806 with Audyssesy switched off - several adjustments were made and Audyssey was run afterwards.

Move on 5 years and Im now setting up my Onkyo 818 - Ive run the Audyssey XT32 set up wizard - measured in 8 places, and had a listen and i can tell its a tad more boomy at the left side of the room closest to the sub than it is at the right.

My question to you is - do I keep the FD or ditch it. since a nice man with more expensive kit than I have set it up and nothing has changed since in terms of speaker Make / Model / placement etc will having the FD in line have any negative effect, am I limiting / throttling anything by having it in line. Am i limiting the quality of the sub frequencies by having this device in line?

Thanks

Steve
If it sounds better with the BFD in place then leave it in place and run Audyssey afterwards. You're not limiting anything by having it inline because audyssey is correcting the room response and the room response is that reproduced by your system after the signal has run through the BFD & hence is accounting for the resulting time and frequency domain changes. It would only be wrong if you were to run audyssey with the BFD off (or in bypass) and then turned the BFD back on after.

Whether you could ultimately achieve the same effect through careful choice of mic positioning while running audyssey is a different Q and rather academic unless you have a burning desire to run audyssey a million and one times :suicide:
 
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If it sounds better with the BFD in place then leave it in place and run Audyssey afterwards. You're not limiting anything by having it inline because audyssey is correcting the room response that is hears and that room response is the post BFD room response, i.e. audyssey is correcting for the response including the delay incurred by routing through the BFD. It would only be wrong if you run audyssey with the BFD off or in bypass and then turned it back on.

Whether you could ultimately achieve the same effect through careful choice of mic positioning while running audyssey is a different Q and rather academic unless you have a burning desire to run audyssey a million and one times :suicide:

I agree that was my next statement but its in all of us to try and fix something that isn't broken:)
 
So to some degree this boomyness is some what the same as before the bfd was placed with in your system

Yes - Afraid so

and when you say on the lefthand or was it the righthand side

Its when you are sat in the right listening position the bass can sound slightly more directional when say in the central main position - there is literally 30-40cm between the two positions.

not just random places with in the room.

No as above - the right side of the room. If you walk from left to right along the back wall of the room with an spl meter in your hand - or the set up mic playing its initial set up tone - the volume rises from 75 - to closer to 85 db - there is 6 db's of variance between the right hand listening position and foot to the right of it.

I agree that was my next statement but its in all of us to try and fix something that isn't broken:)

Last time I got quite obsessed in trying to cure room frequency issues, with test tones and REW I couldn't resolve all the problems to the extent I'd like, and with extremely limited subwoofer placement options I was running out of ideas, thats why I paid a considerable amount of money to get HCE to help me :(

Im not going through that again as it detracted from the enjoyment of the system.

Ill put the BFD back in line even if it does just satisfy the placebo effect - re run Audyssey and leave it alone.
 
Surely no amount of eq can make it sound good in all positions, even if you tamed the boom at the sides then your middle position would be lacking?
 
A second sub is probably the best solution to smooth response across a larger area in your room, there is only so much eq can do.

I find that with 818 the boom has been tamed in the MLP but if you move 2-3ft left or right you get a node.
 
Surely no amount of eq can make it sound good in all positions, even if you tamed the boom at the sides then your middle position would be lacking?
It depends on your room as to whether you "need" 1 sub or more just as the efficacy of your eq depends on your room (and your ability to use it). As far as the OP is concerned, if it was fine before then changing the processor alone should make next to no difference to the sub (assuming new processor has same target response as before) though of course it is likely to change the mains and this might colour your perception.
 
Y


No as above - the right side of the room. If you walk from left to right along the back wall of the room with an spl meter in your hand - or the set up mic playing its initial set up tone - the volume rises from 75 - to closer to 85 db - there is 6 db's of variance between the right hand listening position and foot to the right of it.

How are you running Audyssey, and is your seating position against a rear wall?
 
How are you running Audyssey, and is your seating position against a rear wall?

Ive put a little piccy on Flikr to show the room layout

http://www.flickr.com/photos/47816698@N04/8946712468/

XT32 is set up for the three positions on the sofa and then place around the Audyseey area as shown using the 818 manual for reference for placement

This slight boomyness is ony apparent in P3

Some pics of the room
IMG_1516.jpg

IMG_1520.jpg

IMG_1519.jpg
 
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It looks and sounds like your using it correctly. I would run Audyssey for the middle of the sofa. So, position one should be mic position one, then 2 and 3, then go about a foot beyond the arms of the chair to the left and right for measurements 4 and 5, then I would do 2 behind the sofa, just above the back of the sofas height and equally spaced, so roughly level with the gaps between the cushions, then take number 8 in front of the sofa in the middle. If thats how you ran it then the results should be fairly consistent across those seats, but to be fair it does sound like you have run it that way.
 
Can i first start off by saying that i really like your setup it looks very smart and clean , i think it was Matt that possibly suggested to maybe add another sub and i would also suggest the same if it can be integrated as well as the first.........just out of interest where is the sub positioned and which sub do you have.
 
Can i first start off by saying that i really like your setup it looks very smart and clean , i think it was Matt that possibly suggested to maybe add another sub and i would also suggest the same if it can be integrated as well as the first.........just out of interest where is the sub positioned and which sub do you have.

His subwoofer I assume is the one detailed in his sig, an BK XLS300pr. The flikr links shows the position of his subwoofer in the room layout diagram, and its located to the front of his room and to the right of the chimney breast.
 
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Can i first start off by saying that i really like your setup it looks very smart and clean , i think it was Matt that possibly suggested to maybe add another sub and i would also suggest the same if it can be integrated as well as the first.........just out of interest where is the sub positioned and which sub do you have.

Thanks Mojogoes - The TV in the Chimney has changed since the picture was taken and the horrible artwork has gone now.

His subwoofer I assume is the one detailed in his sig, an BK XLS300pr. The flikr links shows the position of his subwoofer in the room layout diagram, and its located to the front of his room and to the left of the chimney breast.

Thats right :) I have the BKXLS300 still - no room anywhere else for a 2nd one though.

Ill whip up a little diag to show how I ran XT32 this time :)
 
Thanks Mojogoes - The TV in the Chimney has changed since the picture was taken and the horrible artwork has gone now.



Thats right :) I have the BKXLS300 still - no room anywhere else for a 2nd one though.

Ill whip up a little diag to show how I ran XT32 this time :)


No mate it still looks a nice chilled out laid back room but a petty about not being able to place another sub..............but stick with the xt32!! although if it doesn't work out you can always fall back to the bfd for something that you know sounds good and won't bug the hell out of ya:)

And i can see that the sofa isn't up against the back wall near the stair as you need access unless you move it just when watching movies.........and it looks like quite a large room with lovely high ceilings..........i grew up in the same type of house.
 
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room2_zps28bede33.png


Sorry for the delay - Hopefully this pic should show how I ran XT32 last time
 

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