Jack Hammer

Jack Hammer

Audioholic Field Marshall
Thanks Highfigh!

And Jack Hammer, I don't know what the **** you are talking about.

I ask questions to gain understanding, and I always appreciate those who help in that process.

But a certain amount of indoctrination always occurs, and sometimes people whole heartedly beleive in certain things without reason, logic or actual evidence. It takes questions, research, and experiments to indentify when this is happening.

If you think me asking questions for people to further explain what they already stated briefly is "discounting", or "ignoring", then I don't even know what to say to you.
Lighten up Francis;)

What I was refering to was you asked for opinions and advice if you should do something that you apparently planned to do regardless of what experiences were shared. You accepted advice from those who thought it was a good idea and didn't seem happy with the advice from those who didn't think it was a good idea. So again, if your gonna do it anyway, why bother asking for advice, both pro and con, in the first place?

Jack
(and if it makes any difference whatsoever, I would have said to try it out and find out for yourself)
 
M

MADCOW

Junior Audioholic
What I was refering to was you asked for opinions and advice
No, I didn't, I asked for tech answers to very specific questions, so that I had the necessery knowledge to setup my experiment and form my own opinion. I beleive in the end, all that matters is how it sounds to me, so of course I had to hear it for myself no matter what. It would be stupid of me NOT to do things that way. It wasn't untill later in the thread I asked for any opinions and that was right before I was about to test it.

You accepted advice from those who thought it was a good idea and didn't seem happy with the advice from those who didn't think it was a good idea.
Anyone who reads this thread can see how not true that is. I don't care about which side people are taking on this, although it's interesting, I care about the quality of the information they use to explain themselves.

By coincidence some of the people who seemed to be against it, weren't really answering all my questions, and didn't provide much explanation.

ANYWAY ...

I tried it ...

It took way too much work to get sounding good, but I got it, although it will still take probably hours and hours of tweaking.

I ended up having to lower my receivers crossover down to 40hz. My speakers are rated below that, and I just couldn't get it sounding good with the crossover going to the 10 inch any higher or by keeping it at 60 and using the subs lowpass to lower it.

The 8 inch I had to set at 110hz. I tried it lower, but it just didn't make enough difference to justify using it at all. The way it is now, it blends very nicely into the fronts, I listened to it with my eyes closed and couldn't really tell a sub was there. What I could tell, particularly on blues based music, was the bass guitar lines seemed way more detailed and disguishable. That was the main difference. And untill I lowered the main crossover down to 40hz, boominess was an issue, although I still need to play around more with subwoofer placement in the room. But for now, this setting make it sound the best I can get it. And it does sound better, but for certain types of music more than others. I don't notice much a difference yet for movies, but havn't tested enough bass intensive scenes yet, and I need to do mroe tweaking anyway.

Peace.
 
M

MADCOW

Junior Audioholic
Update .. I'm not sure why it sounds different this way, than if I simply raise the cross over on the bigger sub up higher, (Which I never thought sounded good), and didn't use the smaller mid bas sub at all. But it seems to sound better this way.

If anyone knows why this may be, let me know.
 
highfigh

highfigh

Seriously, I have no life.
Update .. I'm not sure why it sounds different this way, than if I simply raise the cross over on the bigger sub up higher, (Which I never thought sounded good), and didn't use the smaller mid bas sub at all. But it seems to sound better this way.

If anyone knows why this may be, let me know.
What is the receiver's high pass set to- still 110Hz? You may be partially canceling a room mode. What are the room dimensions?
 
M

MADCOW

Junior Audioholic
The room is 15ft by 14 ft, with the front speakers aiming down the 15ft stretch, with about a foot of space behind them, and 2 open doorways at the back right corner of the room. (opposite side as speakers) One on the side wall, and one on the back wall.

The crossover on the receiver is set to 40 hz with all speakers as small, and the 10 inch sub hooked into "subwoofer out" on the receiver. And for the 8 inch sub, hooked into "front preout", I used the sub's filter to set it to 110 hz.
 
TLS Guy

TLS Guy

Audioholic Jedi
Yeah, but in this case, if it works, like I stated, each sub will be responsible for a seperate frequency range. There will be no overlap, so why would there be a volume gain at all?

As long as the receiver's crossover setting effects front preout, I can't see why this wouldn't work.

I will have to hear how it sounds for sure, I just want to know the tech ups and downs relative to my plan.
I think you will have serious trouble getting a smooth response. Your small sub will be a bandpass filter for just one octave, eight full tones. Because of crossover overlap you will have huge bandpass gain issues.

If I were you I would set your speakers to large, and set the crossover of your small sub to cut in an octave above the F3 of you mains, and set your LFE sub to 60. I think that will work best of you want to use two subs.

Using a driver over a narrow band width is never a good plan. Having four and preferably five octaves between crossover points works out best.
 
M

MADCOW

Junior Audioholic
TLS, thanks. Are you talking about if my small sub is still hooked into front preout, or if it was in sub out?

Because if you mean to try that setup with the small sub in front preout I can try it right now.
 
TLS Guy

TLS Guy

Audioholic Jedi
TLS, thanks. Are you talking about if my small sub is still hooked into front preout, or if it was in sub out?

Because if you mean to try that setup with the small sub in front preout I can try it right now.
Yes connect the small sub to the preout and use its internal crossover set an octave above the F3 of the mains.

Connect the other one to the LFE and use the receiver crossover, set to 60 Hz for a start.

Be careful not to set the small sub too loud. Make sure at least your mains are set to large. Phase the subs up carefully. I would phase the small sub to the mains with the big sub off for a start and then bring in the big one and phase that, to the mains and the small sub. At least that is the way I would go about it.

I would try having the small sub in the vicinity of the mains for a start, and the bigger sub the opposite end of the room perhaps.

Do not common the left and right preouts, or you will have mono.
 
M

MADCOW

Junior Audioholic
Do not common the left and right preouts, or you will have mono.
So you're saying hook either the left or right front preoout into the sub but not both ... But the sub already is mono, so "commoning" the left and right preouts to the sub, will turn the front speakers in use into mono?

After this, I'm about to try it.
 
TLS Guy

TLS Guy

Audioholic Jedi
So you're saying hook either the left or right front preoout into the sub but not both ... But the sub already is mono, so "commoning" the left and right preouts to the sub, will turn the front speakers in use into mono?

After this, I'm about to try it.
If your sub has line level left and right inputs, you can use both pre outs, as those inputs will be buffered and the channels summed to mono after the buffer amps.

Receivers do not generally have buffer amps at the pre outs, so if you couple them you will have mono to your mains.

So if your sub does not have left and right inputs, you will have to use either left or right pre out. To use both you would need to build buffer amps.
 
Last edited:
M

MADCOW

Junior Audioholic
Ok, thanks man so far I only hooked into "right preout", but I was going to try coupling them, I just didn't have the peice for it.

So in theory, wouldn't this mean the right speaker should appear to be more bassy than the left, especially when channel seperation is very obvious?
 
TLS Guy

TLS Guy

Audioholic Jedi
Ok, thanks man so far I only hooked into "right preout", but I was going to try coupling them, I just didn't have the peice for it.

So in theory, wouldn't this mean the right speaker should appear to be more bassy than the left, especially when channel seperation is very obvious?
Obviously, it would be better to have the bass from both channels. However the bass will not localize to the sub. The bass at those frequencies is picked up on all microphones, unless extreme isolation is used, so this minimizes the imbalance.

If you like the set up, buffer amps would be an improvement.
 
Last edited:
M

MADCOW

Junior Audioholic
I must admit it sounds better now. I usually don't set my front to large though, but I did it exact how you said to try, and it does sound better. Setting it to large, meant that I could have the filter on the 8 inch way lower, and still notice a difference in sound from it. For music anyway, I never tested it on anything else.

The 8 inch sub now cuts in at 70hz, and the 10 inch at 60hz.

But now I wonder, if the fronts are now set to large, and the 8 inch sub running from the front preout, is there any real difference in theory than from having the 8 inch from the subwoofer out?

My guess is that plugged into the front preouts it wont go below 20hz, whereas the other sub will, although at decreasing levels?
 
Last edited:
TLS Guy

TLS Guy

Audioholic Jedi
I must admit it sounds better now. I usually don't set my front to large though, but I did it exact how you said to try, and it does sound better. Setting it to large, meant that I could have the filter on the 8 inch way lower, and still notice a difference in sound from it. For music anyway, I never tested it on anything else.

The 8 inch sub now cuts in at 70hz, and the 10 inch at 60hz.

But now I wonder, if the fronts are now set to large, and the 8 inch sub running from the front preout, is there any real difference in theory than from having the 8 inch from the subwoofer out?

My guess is that plugged into the front preouts it wont go below 20hz, whereas the other sub will, although at decreasing levels?
I thought your object was to extend the bass of your mains which this does.

The difference between what you have now and having both subs connected to the LFE is that one sub is just extending the bass of the mains and the other is handling the LFE.

For your situation that is probably optimal as an eight inch sub might not handle the 20db explosion boosts etc. on the LFE channel

The main reason I did this is because you wanted to extend the bass of your mains. I understand form the 70 Hz crossover, you mains must have an F3 of around 35 Hz, so what you have is really the only practical way of doing what you desire with what you have.

As you probably know, I'm a rebel when it comes to subs, in that I don't use one in my main system, although LFE channel information is captured. The issue of bass management, and how to set up subs has largely been dictated by Lucas Labs. On this issue I don't see completely eye to eye.

My experiments and theoretical considerations told that the best bass would be achieved by seven extended range speakers. Interestingly a paper at the Holland AES a few months ago showed that to be so.

I have come close to that. All my speakers are set to large. In room, the mains extend to 20 Hz before the spl drops, and the rears come close to that. The center can not be so big, but the F3 of the TLS is 42 Hz with 12 db roll off per octave, rather than a ported speakers 24db per octave, and has significant output to 20 Hz.

The surrounds have to be smaller for aesthetics, but they are sealed speakers with Dynaudio drivers which have 2.5 inch diameter voice coils, that can easily handle whatever Hollywood throws at them. F3 is 53 Hz, but again, roll of is 12 db per octave, so there is good usable response to 30 Hz. They don't sound bass shy at all when used as a stereo pair. In fact people used to comment on how good the bass response was when those speakers were with me on location recording. So what I have is close to the seven extended range speakers, and four of them are truly full range speakers, with a bass most subs can't achieve.

I have friends with mains that have good mains with bass response to 30 Hz, Hz. I have found that if the mains have a good quality bass, and are able to achieve good spl to the 30 Hz region, that it sounds best if the mains, at least, are set to large. The issue is, and this is where Lucas labs have a point is that speakers that have extended bass response at a robust spl, will always be at a high price point, and certainly cost more than most members on the these forums would want to pay. So the issue becomes off loading speakers that might be damaged by Hollywood's effects, or at least have the deep bass muddy the mid range of the speakers. Also offloading receiver amps, that can not do the best delivering the currents required to allow most speakers to perform their best below 60 Hz is an issue the Lucas approach helps.

So for most situations, the Lucas Labs way of doing things makes sense, and certainly gives the best bag for the buck with the equipment budget. I don't believe it is the route to the "ultimate".

I just received my December issue of Gramophone magazine yesterday. It has a sampler SACD. Track 13 is the opening of the first movement of Symphony No. 12 by Kalevi Aho, from the Lahti symphony orchestra Finland, on the BIS label.

It opens with an extended antiphonal tympani section which leads into a brass fanfare. Hearing my big lines either end of the studio answer each other with power clarity and and tight deep boom less bass was quite a thrill. I think that sampler may have sold me that CD!
 
M

MADCOW

Junior Audioholic
For your situation that is probably optimal as an eight inch sub might not handle the 20db explosion boosts etc. on the LFE channel
Actually, this 8 inch is better than most 8 inchers, most 10s even, there is a lot of crappy subs out there, which I know doesn't say much, my 10 is just better for LFE, and I felt the 8 would "hold it back" in terms of LFE performance, whic is sort of what I meant when I asked about what the difference is now, but I get it now.

Either way, right now is probably the best my system has sounded, and the only thing I didn't do exactly to your recomendations by the way is the subwoofer placement because I don't have a long enough cable at the moment.

I still need to play around more with phasing and sub placement, to get the ultimate out of my gear, but from the changes that are already made, my system made a gain for the better. In the end, my fronts sound better than what they are, which is really what I wanted. Because I can't afford better. I might upgrade my 10 inch sub in the Future to one of the better SVS subs, but the room I'm in, my 10 is more than enough even for movies.

The F3 on my surrounds is 40hz and 50hz, they are still set to small. Which always sounded the best for them (I did try them on large). I have yet to try my new setting using the surrounds and center though. I first want to perfect sub placement and phasing which will probably take me all day today. :)
 
Last edited:
M

MADCOW

Junior Audioholic
Well, after more testing and trying to tweak things, I think I may just end up going back to just the one sub afterall. Go figure.

I'ts just too much work to set this up right, and although it sounded better for certain things, it sounded worse for others.

Oh well, I learned a few things in the process.

I think the only worth while subwoofer upgrade to my system would be to get a real good 12 inch sub, but for now, my particular 10 inch is more than enough for my room and sounds great musically.
 
newsletter

  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top