The shape of the roll off can be a good diagnostic to help separating room and speaker effect. Sharp roll off is sometimes due to room.
And then there were three...
- Thread starter spiritofmusic
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The shape of the roll off can be a good diagnostic to help separating room and speaker effect. Sharp roll off is sometimes due to room.
Glad to hear Phil helped. Zu Definition has been designed from the beginning to be an easy to setup loudspeaker. 42hz seems about right in a large room per memory.
In my subsequent (much) smaller room, xover had to be higher due to a suckout between 50-100hz. Phil still preferred 42hz, but I hated the hole so started at 100hz and dialed it down 5hz at a time until 65hz or so was the best balance. I listen to a lot of electronica which has beats in that frequency zone and requires mid-bass shove.
Sub Integration
All, I thought I would chime in on this already lengthy thread as I have full range speakers (Vivid G1) and also use 4 18" subs in my 28X22X12 well treated room. I feel that my sub integration is very, very good. People who come over to listen frequenly ask if the subs are on. Only when I turn the off is there a "wow" moment. The major thing they add is an increased sense of spaciousness. I have tried multiple integration techniques (Welti, JL-audio CR-1 and Geddes) and currently run the mains full range with the subs blended in. I gave up on the CR-1 as when I did A/B/A testing I could definitely hear a loss of dynamics with it in the system -- Particularly with guitar strings.
The need for subs and deep bass etc. It is well documented (and audiophiles know intuitively) that humans are really good at ignoring dips in the frequency response. In fact, we humans will even psychoacoustically add the fundamental frequency in say a double bass E at ~40 Hz even though a speaker may not play that low. Why is this important to a discussion on subs? well every rectangular room will have 6 dips in the frequency response due to the sound wave reflection from the 6 surfaces of the room. (there will also be dips at the harmonic frequencies but these are not typically in the lower bass region). This effect has two names -- the Allison Effect or SBIR (Speaker Boundary Interference Response). These dips are not really preventable as it is almost impossible to get enough absorption. What can be done is moving the dips around by moving the speaker or listener position. The closer the speaker is to a boundary the higher the frequency for the dip. A path length difference of 7 feet corresponds to a dip at 80Hz. Dividing the path difference by 2 gives a speaker to wall distance of 3.5 feet. So if you position your speakers at least 3.5 feet from the wall the dip will be below 80Hz and start to enter subwoofer territory. IMHO subs are best used to fill in these dips caused by SBIR).
Sub placement: I see a lot of people position their subs very close to the main speakers. If this is the case, then since the subs are very close to the same distance to the walls as the main speakers (I'm referring to full range speakers here) they will suffer the same acoustic cancellation and not be of much help unless the delay is adjusted so the sub's sound wave is out of phase with the main speaker. For example, In my case, I site about 10.5 feet from the rear wall. This gives a dip at 27 Hz. If I put the sub next to the mains I have the same dip in frequency at 27 Hz no matter how loud I play the subs.
Room Size etc: Room size plays a role because by definition as the room gets smaller the speakers have to get closer to the walls and the SBIR frequency starts to go up outside of subwoofer range (defined as 80Hz). However, this causes the opposite problem of exciting the room modes since the speakers are closer to the walls. Not picking on Steve Williams at all here. Just a reference since he has a great photo of his room (which looks awesome BTW). It appears that he has the Wilson's pretty close to both the side and rear walls. maybe 3-4 feet to the center of the woofer. This would cause a dip at about 70Hz. If the ceiling is 9' then this will cause a dip at about 50Hz. Both of these are outside where he was crossing over the sub at 35Hz. I don't know how far from the rear wall he sits but the subs won't help with this as they are right next to the mains and will have the same acoustic null coming from the back wall. If my estimates are correct then it makes sense that Steve didn't like the subs as they weren't really helping anything.
Integrating subs is a lot of work but to me the reward is worth the effort. I firmly believe that unless you are taking measurements with at least a hand held RTA (REW and a Mic is preferred) then it just guesswork on the integration and will take forever and I can see how someone would just give up. I attached my in room Bass frequency response (1/12 Octave Smoothed) with and without subs. Hopefully, you can see the dips in my no-subs data that are caused by SBIR and that they are smoothed with the subs. Additionally, I have a long decay at 21Hz which was evident without the subs. With the subs I tailored this so the frequency response starts to drop off at 25Hz.
Enjoy the music.
All, I thought I would chime in on this already lengthy thread as I have full range speakers (Vivid G1) and also use 4 18" subs in my 28X22X12 well treated room. I feel that my sub integration is very, very good. People who come over to listen frequenly ask if the subs are on. Only when I turn the off is there a "wow" moment. The major thing they add is an increased sense of spaciousness. I have tried multiple integration techniques (Welti, JL-audio CR-1 and Geddes) and currently run the mains full range with the subs blended in. I gave up on the CR-1 as when I did A/B/A testing I could definitely hear a loss of dynamics with it in the system -- Particularly with guitar strings.
The need for subs and deep bass etc. It is well documented (and audiophiles know intuitively) that humans are really good at ignoring dips in the frequency response. In fact, we humans will even psychoacoustically add the fundamental frequency in say a double bass E at ~40 Hz even though a speaker may not play that low. Why is this important to a discussion on subs? well every rectangular room will have 6 dips in the frequency response due to the sound wave reflection from the 6 surfaces of the room. (there will also be dips at the harmonic frequencies but these are not typically in the lower bass region). This effect has two names -- the Allison Effect or SBIR (Speaker Boundary Interference Response). These dips are not really preventable as it is almost impossible to get enough absorption. What can be done is moving the dips around by moving the speaker or listener position. The closer the speaker is to a boundary the higher the frequency for the dip. A path length difference of 7 feet corresponds to a dip at 80Hz. Dividing the path difference by 2 gives a speaker to wall distance of 3.5 feet. So if you position your speakers at least 3.5 feet from the wall the dip will be below 80Hz and start to enter subwoofer territory. IMHO subs are best used to fill in these dips caused by SBIR).
Sub placement: I see a lot of people position their subs very close to the main speakers. If this is the case, then since the subs are very close to the same distance to the walls as the main speakers (I'm referring to full range speakers here) they will suffer the same acoustic cancellation and not be of much help unless the delay is adjusted so the sub's sound wave is out of phase with the main speaker. For example, In my case, I site about 10.5 feet from the rear wall. This gives a dip at 27 Hz. If I put the sub next to the mains I have the same dip in frequency at 27 Hz no matter how loud I play the subs.
Room Size etc: Room size plays a role because by definition as the room gets smaller the speakers have to get closer to the walls and the SBIR frequency starts to go up outside of subwoofer range (defined as 80Hz). However, this causes the opposite problem of exciting the room modes since the speakers are closer to the walls. Not picking on Steve Williams at all here. Just a reference since he has a great photo of his room (which looks awesome BTW). It appears that he has the Wilson's pretty close to both the side and rear walls. maybe 3-4 feet to the center of the woofer. This would cause a dip at about 70Hz. If the ceiling is 9' then this will cause a dip at about 50Hz. Both of these are outside where he was crossing over the sub at 35Hz. I don't know how far from the rear wall he sits but the subs won't help with this as they are right next to the mains and will have the same acoustic null coming from the back wall. If my estimates are correct then it makes sense that Steve didn't like the subs as they weren't really helping anything.
Integrating subs is a lot of work but to me the reward is worth the effort. I firmly believe that unless you are taking measurements with at least a hand held RTA (REW and a Mic is preferred) then it just guesswork on the integration and will take forever and I can see how someone would just give up. I attached my in room Bass frequency response (1/12 Octave Smoothed) with and without subs. Hopefully, you can see the dips in my no-subs data that are caused by SBIR and that they are smoothed with the subs. Additionally, I have a long decay at 21Hz which was evident without the subs. With the subs I tailored this so the frequency response starts to drop off at 25Hz.
Enjoy the music.
Sbnx, great post. I believe the sadly departed Rodney ran four subs in "swarm" mode too.
For my sins, I'm currently restricted to subs inbuilt to the subs, so unless I go for outboard units, then I'm restricted to a useable set of freq, level, phase and PEQ controls.
I remain intrigued about those users of large full range speakers that have no user adjustability, and the message I'm getting from guys here is that as long as the spkr is not overwhelmingly too large for the room (no Arrakis in the spare bedroom), a smooth bass response can be achieved purely by experimenting w spkr placement, listening position, and judicious acoustic treatments.
Sbnx, can I ask, had you not gone down the subs route, would you have been able to fully dial yr G1s in purely by shifting them around?
FWIW, my personal logjam on subs integration is fully breaking w finding THE settings that work in my room, and critically also raising my Zus, hence increasing the subs drivers to floor gap.
Bass is warmer, more extended, tighter, and critically almost zero bleed into the lower mids/upper bass output.
For my sins, I'm currently restricted to subs inbuilt to the subs, so unless I go for outboard units, then I'm restricted to a useable set of freq, level, phase and PEQ controls.
I remain intrigued about those users of large full range speakers that have no user adjustability, and the message I'm getting from guys here is that as long as the spkr is not overwhelmingly too large for the room (no Arrakis in the spare bedroom), a smooth bass response can be achieved purely by experimenting w spkr placement, listening position, and judicious acoustic treatments.
Sbnx, can I ask, had you not gone down the subs route, would you have been able to fully dial yr G1s in purely by shifting them around?
FWIW, my personal logjam on subs integration is fully breaking w finding THE settings that work in my room, and critically also raising my Zus, hence increasing the subs drivers to floor gap.
Bass is warmer, more extended, tighter, and critically almost zero bleed into the lower mids/upper bass output.
Spiritofmusic,
I somehow missed the post about Rodney's passing. I am pretty bummed about that. He seemed to be a great guy who always had great posts. I regret never getting to meet him as we are kindred audiophile spirits. We both built our own room; we both had Vivid G1's and we both used multiple subwoofers. RIP Rodney.
We should define the term "smooth bass". Technically "smooth" would be a flat (+/- say 1-3 dB) frequency response from 20 Hz up to the Schroeder frequency which is typically between 100 to 200 Hz for most small rooms. So there would be no "hills" and no "valleys". The hills and valleys are caused by two different acoustic phenomena.
I spoke to the valley's above being SBIR. There are only two ways not to have them. 1. 100% absorption down to 20Hz on all walls or 2. put your speakers and listening position up against the walls. So realistically, any audiophile room with speakers and a listening position that is placed for stereo is going to have valleys. Again, our ears do a great job of ignoring these and only when you actually fill them in do you notice what you have been missing.
The other problem is the "hills or peaks". These are caused by the speaker(s) interacting with room modes. When your speaker is placed in a spot that excites a specific mode then there will be a peak in the frequency response that corresponds with that mode. Peaks are really bad. There are two things that happen. First, our ears really focus on the louder frequency and "ignore" the quieter frequencies around it. This leads to what is called one-note bass. e.g. if you have a 10db peak in your frequency response at say 60Hz then anything you play with bass is going to sound like a 60Hz beat. Second, room modes will decay in time. This is called ringing. When this happens the bass becomes smeared, boated or thick. What is happening is that the room is still playing that frequency when the speaker has moved on to the next note. So in effect you have the speaker and the room "playing" at the same time. This smears the bass.
Now that we have all that out of the way what do people mean when they say "smooth bass"? I believe they mean that there are no bass frequency peaks more than 3-5 dB above anything else and that all the room decay is less than 300ms. If these criteria are met then the bass will sound "tight" and articulate. (Even though you have valleys of missing frequency content).
Did I move my speakers around to find the smoothest bass? Absolutely! You can see from the "no sub" frequency response above that I don't have any bass notes sticking out and if I showed the waterfall plot you won't see any decay longer than 300ms. I implemented subs to give true smooth bass where the valleys are filled in as well as no peaks.
Are you taking measurements as you make adjustments to the speakers and subs? REW is free and the necessary hardware (a mic, preamp and cables will be less than $200). This is a bit of a learning curve but there are plenty of youtube videos.
I somehow missed the post about Rodney's passing. I am pretty bummed about that. He seemed to be a great guy who always had great posts. I regret never getting to meet him as we are kindred audiophile spirits. We both built our own room; we both had Vivid G1's and we both used multiple subwoofers. RIP Rodney.
We should define the term "smooth bass". Technically "smooth" would be a flat (+/- say 1-3 dB) frequency response from 20 Hz up to the Schroeder frequency which is typically between 100 to 200 Hz for most small rooms. So there would be no "hills" and no "valleys". The hills and valleys are caused by two different acoustic phenomena.
I spoke to the valley's above being SBIR. There are only two ways not to have them. 1. 100% absorption down to 20Hz on all walls or 2. put your speakers and listening position up against the walls. So realistically, any audiophile room with speakers and a listening position that is placed for stereo is going to have valleys. Again, our ears do a great job of ignoring these and only when you actually fill them in do you notice what you have been missing.
The other problem is the "hills or peaks". These are caused by the speaker(s) interacting with room modes. When your speaker is placed in a spot that excites a specific mode then there will be a peak in the frequency response that corresponds with that mode. Peaks are really bad. There are two things that happen. First, our ears really focus on the louder frequency and "ignore" the quieter frequencies around it. This leads to what is called one-note bass. e.g. if you have a 10db peak in your frequency response at say 60Hz then anything you play with bass is going to sound like a 60Hz beat. Second, room modes will decay in time. This is called ringing. When this happens the bass becomes smeared, boated or thick. What is happening is that the room is still playing that frequency when the speaker has moved on to the next note. So in effect you have the speaker and the room "playing" at the same time. This smears the bass.
Now that we have all that out of the way what do people mean when they say "smooth bass"? I believe they mean that there are no bass frequency peaks more than 3-5 dB above anything else and that all the room decay is less than 300ms. If these criteria are met then the bass will sound "tight" and articulate. (Even though you have valleys of missing frequency content).
Did I move my speakers around to find the smoothest bass? Absolutely! You can see from the "no sub" frequency response above that I don't have any bass notes sticking out and if I showed the waterfall plot you won't see any decay longer than 300ms. I implemented subs to give true smooth bass where the valleys are filled in as well as no peaks.
Are you taking measurements as you make adjustments to the speakers and subs? REW is free and the necessary hardware (a mic, preamp and cables will be less than $200). This is a bit of a learning curve but there are plenty of youtube videos.
Sbnx, I'm afraid I'm doing it the hard (aka probably incorrect) way ie purely by ear.
I've managed to get my spkrs 8' ft from front walls and 4' from side walls, which has resulted in the most linear sound.
Then I've hit upon the right balance of xover freq, level, phase, PEQ freq and gain.
And now I'm experimenting with spkr spikes and footers, different materials to spike the spkrs on, and crucially the subs - flr gap.
I don't doubt I'd make clearer decisions the way you've described, but I've made some important breakthroughs in the last few days.
I've managed to get my spkrs 8' ft from front walls and 4' from side walls, which has resulted in the most linear sound.
Then I've hit upon the right balance of xover freq, level, phase, PEQ freq and gain.
And now I'm experimenting with spkr spikes and footers, different materials to spike the spkrs on, and crucially the subs - flr gap.
I don't doubt I'd make clearer decisions the way you've described, but I've made some important breakthroughs in the last few days.
Hello,
Being curious here, as I ponder to replace my Herbie's Lab with Rollerblocks 2.5+. Why did you get rid your Rollerblocks and what was the first benefit of them ?
Thank you
Kantx, hi.
It was a chance chat w Audiophile Bill.
I mentioned my Zus were on the RBs, and he was adamant spkrs need to be sited inertly on the floor.
I argued in favour of the RBs, but felt sufficiently spurred on to go back to spiking.
And haven't looked back.
So, first stock spikes.
Then some bespoke Lead spikes.
Then RevOPods after trial versus IsoAcoustics Gaias.
Finally the RevOPods on Panzerholz.
All on Symposium Svelte Shelves.
Kantx, my previous room seemed to benefit from RBs on Svelte Shelves, and it never occurred to me to try anything else in my new space.
Maybe my very different floor mitigates against RBs.
Maybe Bill is right, spkrs must be inert sited on floor.
It was a chance chat w Audiophile Bill.
I mentioned my Zus were on the RBs, and he was adamant spkrs need to be sited inertly on the floor.
I argued in favour of the RBs, but felt sufficiently spurred on to go back to spiking.
And haven't looked back.
So, first stock spikes.
Then some bespoke Lead spikes.
Then RevOPods after trial versus IsoAcoustics Gaias.
Finally the RevOPods on Panzerholz.
All on Symposium Svelte Shelves.
Kantx, my previous room seemed to benefit from RBs on Svelte Shelves, and it never occurred to me to try anything else in my new space.
Maybe my very different floor mitigates against RBs.
Maybe Bill is right, spkrs must be inert sited on floor.
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