newbie

[Joshua_j]

Hi all, i have been reading through the forum here for a while and I have also tried to weed through the stuff on avs forum. In general, I think that there is a dearth of info on so many of the sub brands out there and most manufacturer claims are so outlandish that I must praise craigsub for having at least formulated a list of subs that the average person can use as a tool.
That being said, I have questions that I will be posting here over time if that is allowed because I do not want to hog the board up with numerous new questions. I understand that there is a search function here and know how to use it, but often my questions don't find answers and it takes so much research that someone without a background in engineering finds it difficult to understand often times.
I live in Los Angeles. I own Dali Euphonia speakers- MS5, CS4, RS3's and the AS2 sub. My room has about 30 foot cathedral ceiling, opens to a 3 story stairwell- so very large volume, but there is significant WAF that must be considered. In reality, cost is not the point for me. Don't get me wrong, I don't like to waste money, but I am more interested in good sound than how much something costs. Also, my tastes have changed and I no longer have the listening time that I used to- mostly movies and TV now...... My musical tastes are ecclectic, but I do not like to listen to opera much and I do like electronic base- old school rap, house music, pink floyd, zeppelin, goodman, hawkins, rollins (both punk and sax)......
That is my background.
I struck a deal with the devil and got a lot of stuff from Magnolia at 0% interest for 4 years-
my sub choice has been limited because I already have the AS2 (for which there are no stats!) but have access to the REL line through them.... has anyone tried the REL line? Are there thought on the B1 line?
that's it for now, responses welcome and appreciated....
Joshua:goodvibes:

[NekoAudio]

If appearance is of great importance, use things that aren't very obvious. For example, a coffee table or end table that is actually the subwoofer. Or building it in a column. Infinite baffle, or rotary woofer. Etc.

[Mike_TX]

Hi all, i have been reading through the forum here for a while and I have also tried to weed through the stuff on avs forum. In general, I think that there is a dearth of info on so many of the sub brands out there and most manufacturer claims are so outlandish that I must praise craigsub for having at least formulated a list of subs that the average person can use as a tool.
That being said, I have questions that I will be posting here over time if that is allowed because I do not want to hog the board up with numerous new questions. I understand that there is a search function here and know how to use it, but often my questions don't find answers and it takes so much research that someone without a background in engineering finds it difficult to understand often times.
I live in Los Angeles. I own Dali Euphonia speakers- MS5, CS4, RS3's and the AS2 sub. My room has about 30 foot cathedral ceiling, opens to a 3 story stairwell- so very large volume, but there is significant WAF that must be considered. In reality, cost is not the point for me. Don't get me wrong, I don't like to waste money, but I am more interested in good sound than how much something costs. Also, my tastes have changed and I no longer have the listening time that I used to- mostly movies and TV now...... My musical tastes are ecclectic, but I do not like to listen to opera much and I do like electronic base- old school rap, house music, pink floyd, zeppelin, goodman, hawkins, rollins (both punk and sax)......
That is my background.
I struck a deal with the devil and got a lot of stuff from Magnolia at 0% interest for 4 years-
my sub choice has been limited because I already have the AS2 (for which there are no stats!) but have access to the REL line through them.... has anyone tried the REL line? Are there thought on the B1 line?
that's it for now, responses welcome and appreciated....
Joshua:goodvibes:

Welcome to TCA.

Mike

[Joshua_j]

If appearance is of great importance, use things that aren't very obvious. For example, a coffee table or end table that is actually the subwoofer. Or building it in a column. Infinite baffle, or rotary woofer. Etc.

thank you for the ideas. I will post pics of my setup....
Joshua

[Joshua_j]

ok, a few questions.
1. is the general consensus that passive radiators are "sloppier"? So the Sunfire, Earthquake, and even the Def Tech Trinity using the passives leads to a less "musical" sound but can help to increase the total output (higher total listening level before failure)?
2. in non servo subs, is the electrical impulse only to move the cone in one direction and in servo controlled subs the electrical impulse will move the cone in both the forward and back direction?
3. there are forward firing, downward firing and side firing subs. Is the sub directional? is the feeling directional? or does it just radiate no matter what the direction of the sub? I guess that the question relates to what is the difference in the designs?
thank you in advance
Joshua

[Ajax]

ok, a few questions.
1. is the general consensus that passive radiators are "sloppier"? So the Sunfire, Earthquake, and even the Def Tech Trinity using the passives leads to a less "musical" sound but can help to increase the total output (higher total listening level before failure)?
2. in non servo subs, is the electrical impulse only to move the cone in one direction and in servo controlled subs the electrical impulse will move the cone in both the forward and back direction?
3. there are forward firing, downward firing and side firing subs. Is the sub directional? is the feeling directional? or does it just radiate no matter what the direction of the sub? I guess that the question relates to what is the difference in the designs?
thank you in advance
Joshua

Don't know much about 1. and 2. Maybe others can help you with those questions. But, the wave length of most frequencies handled by a sub (80 Hz and below) are long enough to be considered non-locatable (non-directionable). Shouldn't make any difference whether one is down-firing, front-firing, or side-firing.

[NekoAudio]

2. in non servo subs, is the electrical impulse only to move the cone in one direction and in servo controlled subs the electrical impulse will move the cone in both the forward and back direction?
3. there are forward firing, downward firing and side firing subs. Is the sub directional? is the feeling directional? or does it just radiate no matter what the direction of the sub? I guess that the question relates to what is the difference in the designs?
thank you in advance
Joshua

I'll skip #1, just because it's probably not best for me to answer. :) It would most likely just boil down to my personal preference/experience anyway.

For #2, the idea is basically to provide feedback so that the electrical signal driving the driver gets adjusted to avoid distortion. If you aren't driving your sub hard to begin with (or perhaps overdriving), this isn't an issue. What I've seen in some measurements of servo-controlled subs is that very low frequencies don't rise equally with other frequencies as your desired output increases, to avoid the associated distortion.

#3 from a sound standpoint there's no issue, like Ajax says. However from a room standpoint, it may make a difference. You want to make sure you have enough clearance between the driver and a surface. The air needs to move, and move to somewhere other than back at the driver.

In some cases you might hear of a driver that isn't designed to be oriented one way or another. This may be due to the "suspension", for lack of a better word.

[toddbagwell]

I'll tackle number one.

From what I've learned about subs, if well designed, there is not much difference between subs above the port or passive radiator tuning frequency when comparing ported/radiator to sealed. Most of the difference lies with the behavior of the sub below its tuning frequency. A sealed sub will drop its response at 12dB per octave, while a ported or PR sub will drop at 4db per octave. Sure, the same diver in the same driver in the same size box will have a slightly different frequency response if ported or sealed, but in general a "well-designed" sub will use the correct amp and box size to maximize driver output.

Some people swear by one or the other. as with any speaker, a sub will react with the room it is in. Ported subs tend to be louder or more efficient per watt above their tuning frequency, but can bottom severely if driven hard below it. For example, the modern action movie has a fair amount of sub 20 Hz content. Some people feel the need to have these subsonic frequencies present at audible / tactile levels in their rooms. Some people do not mind if the low end isn't exactly as it is on the disc. if you listen to mostly music, most people recommend not worrying about the sub 35hz content as most music has frequencies above this point. the notable exception is electronic/dance music and organ music which can go as low as 16Hz!

I'd recommend the DIY sub and Speaker forum on AVS- while occasionally hostile, there are a lot of very intelligent posters, and FAQ's about sub design. I've learned enough to feel confident designing and building my own subs.

There are several programs used to model simulated enclosures, drivers, and box alignments. Many people use a program called "WinISD" it allows you to change various parameters and see the performance and effects various changes have on output. I found it quite helpful to play around with it, as it helps me understand why manufacturers make the compromises they do in designing their subs.

If you aren't into reading/learning on your own, I'd recommend something from TCA- Craig knows his stuff, and will produce great sounding subs of any design.

hope some of this helps

todd

[Joshua_j]

thank you all for taking the time to respond. I have to digest the answers.
Joshua

[Joshua_j]

I have been reading through all of the links. Thank you everyone for directing me to those forums. A lot of info to understand and digest.
I have a question, in most of the DIY and mail-order subs, setting up the subs seems to involve already having a microphone and equalizer. It seems like brands like velo and jl include equalizers in/with their amplifier units..... is this part of the cost difference?
Joshua

[Mike_TX]

Sub EQ

I have been reading through all of the links. Thank you everyone for directing me to those forums. A lot of info to understand and digest.
I have a question, in most of the DIY and mail-order subs, setting up the subs seems to involve already having a microphone and equalizer. It seems like brands like velo and jl include equalizers in/with their amplifier units..... is this part of the cost difference?
Joshua

I am not the sub guru, but there are various proprietary sub/room EQ solutions.

I started a thread at HTS on Sub EQs as I was just trying to educate myself.

Here is a link that might give you some more reading material in a semi-structured context.

Here is a partial list from that thread:

Subwoofer Equipment for Calibration/Optimzation (not SPL meters)
- AV123 R-DES (no longer made)
---- Review - Secrets of Home Theater & High Fidelity 9/2006
- Behringer Feedback Destroyer (BFD) Pro DSP1124P - link
- Behringer Ultradrive Pro DCX2496 - link
- DSPeaker Anti-mode 8033 - link
- Rives Audio PARC (Parametric Adaptive Room Compensation) - link
- QSC DSP-30 - link
- SVS AS-EQ1 Subwoofer EQ - link
- Velodyne SMS-1 - link


Calibration Software
- Acoustisoft ETF
---- RPlusD (= ETF6, 3/3/09) - link
---- ETF5 (replaced by RPlusD = ETF6) - link
---- Rubinson, Kalman, 7/1998 – Stereophile – on ETF4 - link
- REW - Room EQ Wizard
---- REW link
---- REW help files - link
- Rives Audio software site - link .
- True RTA - link



I've just started playing with the Audyssey Pro kit for my whole HT setup (including sub EQ). I'll attach a PDF so you can see the before and after results.

Mike

[Jason]

It seems like brands like velo and jl include equalizers in/with their amplifier units..... is this part of the cost difference?
Joshua

Yes, that is part of the price difference. But Velo and JL are retail/brick and mortar products, so there is an additional markup in that distribution chain that is a significant part of their price.

The auto EQ's are nice, but there are several outboard solutions for that if you end up with a unit that doesn't have that feature built in. Also, there are several subs out there that have a single band eq built in to tame your worst room peak. All you need for that is an inexpensive spl meter and test tones.

[Joshua_j]

Thank you for the responses, more studying!
Joshua

[Joshua_j]

the sub that I currently have has opposing drivers, mounted on the sides of this very very heavy cabinet. where would i measure spl and other measuremenst from (ie from my listening position?)? I understand that bass frequencies are not "directional" but surely there must be some directionality to it.....
thank you,
Joshua

p.s. here are the factory specs:

"The AS2 includes a heavy, absolute zero mechanically
grounded polymer granite base with integrated adjustable
spikes. A 12” long-throw woofer is placed in each end panel,
connected electrically to work in opposite directions, canceling
vibrations and resonances in the subwoofer cabinet, leaving a
totally inert, motionless system.
In order to obtain the ultimate in speed, pitch definition and
accuracy, the AS 2 is a dual chamber, sealed system with mild
equalization in the DALI Class D amplifier to be able to reach
really deep. The amplifier is a 650 Watt (1300 Watt peak)
high-efficiency design."

Frequency range (+/- 3dB) [Hz]: 25,0 - 200,0
Maximum SPL [dB]: 120,0
Crossover frequencies: 40 - 100
Enclosure type: Closed box
Connection input(s): Mono "line level" (LFE);S
Connection output(s): Stereo "line level" (high
Functions: Crossover frequency;Varia
Recommended placement: Sub;Floor
Loudspeaker type: Subwoofer
Max loudspeaker dimensions incl. base and grille (H40x5W Xx D6)7 [5m Xm 6]:15
Loudspeaker weight including base and grille [kg]: 64,0

[Mike_TX]

Spl

the sub that I currently have has opposing drivers, mounted on the sides of this very very heavy cabinet. where would i measure spl and other measuremenst from (ie from my listening position?)? I understand that bass frequencies are not "directional" but surely there must be some directionality to it.....
thank you,
Joshua

p.s. here are the factory specs:

"The AS2 includes a heavy, absolute zero mechanically
grounded polymer granite base with integrated adjustable
spikes. A 12” long-throw woofer is placed in each end panel,
connected electrically to work in opposite directions, canceling
vibrations and resonances in the subwoofer cabinet, leaving a
totally inert, motionless system.
In order to obtain the ultimate in speed, pitch definition and
accuracy, the AS 2 is a dual chamber, sealed system with mild
equalization in the DALI Class D amplifier to be able to reach
really deep. The amplifier is a 650 Watt (1300 Watt peak)
high-efficiency design."

Frequency range (+/- 3dB) [Hz]: 25,0 - 200,0
Maximum SPL [dB]: 120,0
Crossover frequencies: 40 - 100
Enclosure type: Closed box
Connection input(s): Mono "line level" (LFE);S
Connection output(s): Stereo "line level" (high
Functions: Crossover frequency;Varia
Recommended placement: Sub;Floor
Loudspeaker type: Subwoofer
Max loudspeaker dimensions incl. base and grille (H40x5W Xx D6)7 [5m Xm 6]:15
Loudspeaker weight including base and grille [kg]: 64,0

The question is why are you measuring SPL?
:no clue:

If it is for your listening -- then measure at your listening position.

If it is for comparison purposes -- then at a standard position (eg, 1m or 2m -- such as a 1m ground plane measure).

So, for you at your listening position.

Mike