|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
65.200.66.17
In Reply to: Re: Fine tuning subwoofers to main speakers.... posted by David Aiken on March 26, 2007 at 00:30:56:
Hi David,
Do you have anymore thoughts on this ? I also felt this, when I added a sub to my 2 main speakers. I am using a receiver in a 2.1 setup, with speakers set to large. I have set the crossover to 40Hz (the min for the sub). I was thinking setting the phase to around 20 or so should take care of the delay, but I still feel the 'loss of sharpness' in the attack. I am hoping a new power cord might introduce a little bit better transients, may be I am hoping too much. Probably I need better sub than my Alon Thunderbolt. Your input is highly appreciated.
Follow Ups:
I posted a reply to this but it doesn't seem to have "stuck".The circuitry in an active sub introduces a small amount of time delay, plus there's the additional delay in arrival time if the sub is further away from you than the main speaker. What that means is that the sound from the sub is always lagging behind the sound from the main speakers. If there's a big enough time lag, you notice the sub as a separate source, in the same way that you notice an echo as coming from a different location to the original sound. If the time lag is too short to be discernible as a separate source, it still 'blunts' the attack of any transients with frequencies in the sub's range. You need the sound from the sub and from the main speakers to arrive almost simultaneously in order to avoid this.
Locating the sub near a main speaker, or at the same distance from you as the main speaker may not be enough, depending on how much delay the sub's circuits introduce.
Phase correction won't fix this. Getting the phase right will affect the overall volume of the sound since the more out of phase the sub sound is, the more cancellation of the main speaker's sound will occur. The problem is simply that if the sounds from all speakers don't arrive together and aren't far enough apart to be experienced as an original sound and echo, the duration of the transient attack phase is going to be increased and that's going to affect how you perceive the attack of the transient.
David ... Doesn't that put the sub's only good placements between the TV and listener or behind the listener? In other words close to the listener and then use time delay if necessary.
Zene
No. In my HT system the sub is behind one of the main speakers and close to the wall, well to the right of the TV. The receiver applies a delay to the signal from the other speakers to match arrival times. You would, however, be correct if my receiver could not provide delays to match the arrival times for each speaker connected to it.In my audio system where the amp offers no such delay facility, it would place the sub to the inside of a speaker and probably partly between me and the audio rack which sits between the speakers. That isn't an ideal position physically, and it would also be close to 2 metres from the nearest wall since my speakers are that far from the wall. If you have your speakers some distance from the walls, this kind of placement will result in a significant loss of boundary reinforcement which is a problem.
I think the electronic delay for the other speakers is a much better solution to the problem of matching arrival times than physical placement, but while delay functions are easily found in AV gear, they aren't common in audio only components. I think the HT people have definitely stolen a march on the audio people in this area.
Hey David,"I posted a reply to this but it doesn't seem to have "stuck"."
Not sure what U mean by "stuck" as I can only surmise your talking about your response to my intitial post to which I had not replied yet. I certainly do respect your opinion, but was only letting the post take it's course, so to speak, to capture other peoples views/experiences.
I have done extensive modification to both my REL subs which has endeared them to be completely seemless in both a music and a HT system. The mods included removing the user interface panel from the subs and mounting them on solid surfaces with vibration absorbtion devices added to the circuitry.
I have also implemented MIT speaker cables between the REL amps and the subs themselves and this alone was a dramatic reduction in sub/main speaker blending issues.
I have even gone so far as to spike the termination box to the floor, apply dampening in the form of #8 lead shot to the MIT termination circuit inside the cable, and then applied vibration absorbtion to the cable which has a profound effect on bass clarity/pitch resolution.
My methods are certainly not in the realm of electronic by any means but I have discovered that cable resonances have a very detrimental effect on bass reproduction and dampening these resonances by mechanical means is truly beneficial :-)Cheers,
No, I meant I had posted a reply to Software Engineer's response to my original post and it seems to have either not got added to the thread of somehow disappeared from it. It said pretty much what I said in the post you replied to.I think there are lot of factors which affect the sound we get. I don't go for major surgery like you, but that's mainly for 2 reasons. I don't k now what I'm doing when it comes to most major surgery, and I also am a lousy quality handyman. I stay away from the sort of interventions you like to make because I know I would make a mess of them, so I concentrate on the things I can do.
Originally I had my REL in the music system and I thought I had achieved a pretty seamless integration. There were no tonal shifts that I noticed in the bass region as one moved into the area with sub coverage, I'd found a location where music timing didn't seem to be affected, and the sub never appeared as a separate source. All in all, I was feeling damn happy about my sub results. Then I changed the receiver in my HT system which was, at that stage, a 2 channel system, and got a Denon with auto-setup and Audyssey equalisation functions. A week or two after I got the Denon, I just had to try the REL in that system which, until then, had never had a sub in it. Bad move. The sub never went back to the audio system because it made a much bigger difference for me with soundtracks rather than music and because the Denon integrated it into the total sound much better than I'd ever managed to do it myself in the audio system. A major aspect of that better integration was the synchroinising of arrival times.
I think I now could put the REL back in the audio system and do better than I had previously, having heard the way it works in the HT system, and I keep telling myself that I should try that one day. It seems, however, that I can't be bothered. The Dynaudio Contour 1.3 SEs in the music system have more than adequate bass for most of the music I listen to, and good enough bass for the rest. I do lose something but not as much as I gain with the REL in the HT system, and the loss in the audio system is a loss I'm prepared to live with since the 1.3 SEs sound so good anyway. I'd also added a bit more acoustical treatment to the room and made a few other minor changes since acquiring the REL and didn't lose as much with its removal as I had anticipated, which made things easier with the change.
I don't think perfection is possible, but it continues to amaze me just how much improvement can be obtained by paying attention to the things that we do feel up to working with. No doubt I could do better if I went down the major surgery route on some things, but there's enough areas where I do feel like playing and fine tuning to keep in in improvements for some time yet without venturing there.
This post is made possible by the generous support of people like you and our sponsors: