OK, I can see readers need one more hint:
Everybody knows the larger the sealed box, the lower the speaker will go. Why doesn't the sim tell me to make a bigger box??????????
Ben
Everybody knows the larger the sealed box, the lower the speaker will go. Why doesn't the sim tell me to make a bigger box??????????
Ben
Hi Mark and All,
I had another day from h..., what got me thinking that it would be a good idea to get into the house rental business so I'd have something for retirement (10 more month - 10 more month...)?
Looking at the drivers from Post #58: "... B&C 18NW100 or a FaitalPro 18HP1020."
They indeed make fine THs that can be forced into the sub 20Hz range (using the same TH geometry the SPLs are almost identical). Still, they cannot outperform the SI 18HT T-TQWT from Post #39, and they are larger. It looks like in this frequency range there is no substitue for shear brute force displacement. I'm attaching the Hornresp Export files for the THs (just the driver parameters change) and for the T-TQWT #2B (w/ Eg reduced so the driver does not exceed Xmax in the passband in the raw Hornresp SPL window (no filling, no filters.)).
All this makes me even more convinced, that the T-TQWT is the right enclosure for this job. And, as always, need it louder, get more boxes. 🙂
Hope I didn't make too many mistakes, it was a hard day.
Regards,
P.S.: Hornresp provides the functionality to increase box size to resemble very large sealed enclosures, being close to so called infinite baffles. Also, data-bass.com has very interesting data on "Room Gain", "Cabin Gain" and "Sealed vs Bass Reflex vs Tapped Horn" in their Articles section, as well as interesting SPL data in their Systems section (this data is 4xPi, add 6dB for 2xPi - in the table click on the 16Hz column to sort the data for 16hz).
I had another day from h..., what got me thinking that it would be a good idea to get into the house rental business so I'd have something for retirement (10 more month - 10 more month...)?
Looking at the drivers from Post #58: "... B&C 18NW100 or a FaitalPro 18HP1020."
They indeed make fine THs that can be forced into the sub 20Hz range (using the same TH geometry the SPLs are almost identical). Still, they cannot outperform the SI 18HT T-TQWT from Post #39, and they are larger. It looks like in this frequency range there is no substitue for shear brute force displacement. I'm attaching the Hornresp Export files for the THs (just the driver parameters change) and for the T-TQWT #2B (w/ Eg reduced so the driver does not exceed Xmax in the passband in the raw Hornresp SPL window (no filling, no filters.)).
All this makes me even more convinced, that the T-TQWT is the right enclosure for this job. And, as always, need it louder, get more boxes. 🙂
Hope I didn't make too many mistakes, it was a hard day.
Regards,
P.S.: Hornresp provides the functionality to increase box size to resemble very large sealed enclosures, being close to so called infinite baffles. Also, data-bass.com has very interesting data on "Room Gain", "Cabin Gain" and "Sealed vs Bass Reflex vs Tapped Horn" in their Articles section, as well as interesting SPL data in their Systems section (this data is 4xPi, add 6dB for 2xPi - in the table click on the 16Hz column to sort the data for 16hz).
Attachments
Bonus points for the t-tqwt...the opening is fairly small, they could probably easily be decorated and fit into decor, might not even have to hide them 🙂
Hi DrDyna,
I might have to build one of these myself. I don't need the SPL, but that T-TQWT looks like a killer HT sub. Maybe a little narrower using two JBL GTO1214?
Regards,
I might have to build one of these myself. I don't need the SPL, but that T-TQWT looks like a killer HT sub. Maybe a little narrower using two JBL GTO1214?
Regards,
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To be completely honest, a portion of my interest in both of these threads are the stuff everyone comes up with for SI 18s 😉
I'm planning on doing a bit of an overhaul in February, and I've been considering getting 4 of those drivers and building 4 more subs..I've just been waffling back and forth on what exactly..the t-tqwt might be the winner, I just worry about integration with the vented ones I have now.
That response curve looks great in the area in which I suspect we might need just a bit more. Things do fall off below 20 Hz. But the SPL - if the sim is accurate - is still above my existing boxes. And the size of the cabinet is a nominal 20" W x 27.5 D x 60" H. That comes out just a bit short of 19 cu. ft. Big - but maybe not too big.
I'm curious, what kind of amp power is needed for this setup? AND can the gain on the amp be used to lower the SPL while still getting this kind of response curve - just at a slightly lower consistent SPL?
Organ amps don't have the problem of frequencies below 20 Hz. being filtered out. I think the figure on the Crown XLS series was 6 dB per 1/2 octave. But almost no organ amps provide output much over 100 watts.
I suspect trying to go into (or pay someone to do so) and change out capacitors in good amps would be an iffy solution. Does anyone know of good - cost effective - amps that extend down to 16 Hz. without that built-in roll off?
Since I don't have the system up and running yet, I can't experiment with the note-by-note adjustment that is supposed to be built-in to the sound engine. That may allow us to overcome the roll off issue. I just don't know what side-effects this process might create. I'm also going to need to experiment with the clipping filter on the Crown XLS1500.
I'm meeting the organ tech today for him to take the organ console and remove the big pipes. Then I'll begin to get the system assembled and start testing the SPL and balance in the Sanctuary.
I'm starting to get a little bit excited. 😀
Bach On
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Oliver.
Try as I might without going into a serious design cycle I don't think I can better your sim. And today is a very busy day for me. I have a boat load of tweeters to ship out.
First I assemble them and then I ships them.
There are a few other possible drivers. But they are not at all in the price range of the HT18.
Try as I might without going into a serious design cycle I don't think I can better your sim. And today is a very busy day for me. I have a boat load of tweeters to ship out.
First I assemble them and then I ships them.
There are a few other possible drivers. But they are not at all in the price range of the HT18.
How does the T-TQWT model against a 19 cu ft ported design? I think a ported design would need a large port to match the T-TQWT in real word, vice virtual, performance.
I have Bjorno designed T-TQWT for an older Exodus Audio Maelstrom X driver (linked by tb46 earlier in the thread). I have not built it because the current sealed version works well enough in my current space but more importantly I cannot obtain more of these drivers due to the companies demise. My desire is to have four of the exact same subs for room node smoothing in my HT via the approach put forth by Welti at Harmon.
Would be great to have a solid T-TQWT design for the SI driver which is inexpensive and readily available.
I have Bjorno designed T-TQWT for an older Exodus Audio Maelstrom X driver (linked by tb46 earlier in the thread). I have not built it because the current sealed version works well enough in my current space but more importantly I cannot obtain more of these drivers due to the companies demise. My desire is to have four of the exact same subs for room node smoothing in my HT via the approach put forth by Welti at Harmon.
Would be great to have a solid T-TQWT design for the SI driver which is inexpensive and readily available.
Hi Bach On,
Post #70: "...what kind of amp power is needed for this setup? AND can the gain on the amp be used to lower the SPL while still getting this kind of response curve..."
The second part first: yes, the amplifier gain shifts the curve up and down without altering the curve shape as long as you are not exceeding the ~ linear range of the driver (~ Xmax) or the amplifier (~ Prms rating).
The first part of the question is a bit more difficult, as it depends on the HP/LP (high pass/low pass)filters used w/ the amplifer speaker system. The professionals on this forum recommend to double the power needed by the speaker to come up w/ the amplifier power.
Raw SPL data (no filters) from Hornresp SI HT18 @ Xmax in T-TQWT#2 (low end high end power peaks):
17Hz 650W 3.53 Ohms
72Hz 647.8W 3.56 Ohms
This matches up well w/ the drivers Prms=600W, which should mean that this driver will not be stressed w/ sound bursts @ the above level. The Crown XLS1500 should have an easy time driving this in the bridged configuration, and should be on the weak side in the standard dual channel configuration.
This all very much depends on how loud will you really be playing this box? If the organ amps Post #70: "...almost no organ amps provide output much over 100 watts." then I wouldn't worry about this at all, as you'll never get anywhere close to the power needed for Xmax.
This subwoofer system is easily of similar efficiency in the sub 30Hz range as any of the professional bass-reflex and passive radiator designs that have been mentioned here and in the other thread, I would not be surprised to find that it equals or outperforms even the four passive radiator/single driver version.
There is one fly in the ointment though, what are the actual T/S (Thiel/Small) parameters of your driver. Sooner or later that needs to be measured, otherwise the simulations may or may not be correct.
Regards,
Post #70: "...what kind of amp power is needed for this setup? AND can the gain on the amp be used to lower the SPL while still getting this kind of response curve..."
The second part first: yes, the amplifier gain shifts the curve up and down without altering the curve shape as long as you are not exceeding the ~ linear range of the driver (~ Xmax) or the amplifier (~ Prms rating).
The first part of the question is a bit more difficult, as it depends on the HP/LP (high pass/low pass)filters used w/ the amplifer speaker system. The professionals on this forum recommend to double the power needed by the speaker to come up w/ the amplifier power.
Raw SPL data (no filters) from Hornresp SI HT18 @ Xmax in T-TQWT#2 (low end high end power peaks):
17Hz 650W 3.53 Ohms
72Hz 647.8W 3.56 Ohms
This matches up well w/ the drivers Prms=600W, which should mean that this driver will not be stressed w/ sound bursts @ the above level. The Crown XLS1500 should have an easy time driving this in the bridged configuration, and should be on the weak side in the standard dual channel configuration.
This all very much depends on how loud will you really be playing this box? If the organ amps Post #70: "...almost no organ amps provide output much over 100 watts." then I wouldn't worry about this at all, as you'll never get anywhere close to the power needed for Xmax.
This subwoofer system is easily of similar efficiency in the sub 30Hz range as any of the professional bass-reflex and passive radiator designs that have been mentioned here and in the other thread, I would not be surprised to find that it equals or outperforms even the four passive radiator/single driver version.
There is one fly in the ointment though, what are the actual T/S (Thiel/Small) parameters of your driver. Sooner or later that needs to be measured, otherwise the simulations may or may not be correct.
Regards,
Because you don't use software which calculate loudspeaker response in the room. See CARA software:
https://www.cara.de/ENU/index.php?load=start.html
"CARA (Computer Aided Room Acoustics) is a very advanced computer program for computing and optimizing Room Acoustics of arbitrary rooms. CARA is based on the sound source imaging method in combination with a back tracing procedure.
CARA analyzes and improves room acoustic influenced sound coloration in a two step procedure:
determination of the basic acoustic properties of the room (Acoustic Ambiance) in combination with suggestions regarding the furnishings (wall materials, furniture) in order to linearize the reverberation time spectrum,
automatic Positional Optimization for the loudspeakers and the listener to minimize sound wave interferences (standing waves) in the listening area.
For a detailed analysis CARA calculates the total sound field data at 1,000-3,000 equally distributed grid points in the room. The evaluation of the sound field data concerns the modal structure (steady state sound pressure distribution), the room response of a Dirac-Pulse excitation in the time domain, the distribution of sound coloration, the sound imaging (stereophonic sound localization), and the speech intelligibility.
CARA provides the expert with a great number of room acoustic reference numbers (frequency dependent reverberation times, sound coloration, speech intelligibility, lateral sound level, or stereophonic sound localization) derived from sound pressure frequency responses or transient room responses/reverberation diagrams.
The special function Auralization renders a listening test in the (virtual) room to evaluate for example sound differences due to different loudspeaker positionings. Any piece of music (two channels Stereo) may be used for this."
Because of the acoustical laws. Read the Thiele and Small papers.
Thanks for your primer lesson. But I've posted several times about room acoustics.
As for the your snarky response to my legitimate question, you don't seem to know why the sim peculiarly outputs small boxes which impair the low frequency response.
Ben
Crown Mod
I mentioned before about contacting Crown to make the changes to the amp, & Mark = mwmkravchenko agreed that they would probably do it, & maybe for free, or low $, as a good advertisment for them 🙂 I really think it's worth a shot/email/phone etc. What have you got to lose 😉
I mentioned before about contacting Crown to make the changes to the amp, & Mark = mwmkravchenko agreed that they would probably do it, & maybe for free, or low $, as a good advertisment for them 🙂 I really think it's worth a shot/email/phone etc. What have you got to lose 😉
Progress report:
Long day. The console has now gone to the hospital. The big Bourdon pipes are gone. I'm going to need to build a small support frame to get over an uneven floor transition from the speaker chamber to the pipe chamber. Then the last two HC12 speakers will be mounted on the frame.
The organ tech has acted reluctant about this project from the beginning. But today he was talking and acting like it was all his idea. I think he was surprised and a little bit impressed with our sound speaker system. In fact, he's a little concerned the bass might be too full. He suggested I turn them around to face the back wall. Go figure!!! 😱
So I have until Aug. 11 to get everything connected and tested. I did a dry connection on all the speaker cables to the amps. I've labeled all of them at each end. Now need to put labels on the speakers. I've left about 8 feet of slack at the amp end to allow us to roll the rack out of the closet and get to the rear for tinkering
We now have electricity in the amp closet. And we have the remote switch that will power up/down the amps when the organ switch is turned on/off. The uninterruptible power supply and the Artisan Sound Engine (actually a computer) will run 24/7. I've got to run an RJ45 network cable from the console pit to the amp rack. And the tech wants a two conductor cable for the remote switch.
I'll be connecting the cables to the speakers this week as I get the last speakers in the speaker chamber I'll connect them and begin performing some adjustments. Need to place the re-enforced upper part on the triangular box. I think the reverberation will be better. I'm also going to mount those Allen Point of Presence speakers on the wall of the pipe chamber. Got more wall space for the mounting brackets with the big pipes gone.
I've got lots to do, but it looks like the advance planning might pay off. But there's always the chance that the light I think I see at the end of tunnel is an oncoming train. 😱
Got Honey-do jobs to do at the house Tues. and Wed. during the day. But I may be able to slip over to the church at night for some work.
I like the plan Oliver has posted for an additional bass box. And I may just try Crown to see if they'll do a custom amp for us. Chutzpa!!! 🙄
Bach On
Long day. The console has now gone to the hospital. The big Bourdon pipes are gone. I'm going to need to build a small support frame to get over an uneven floor transition from the speaker chamber to the pipe chamber. Then the last two HC12 speakers will be mounted on the frame.
The organ tech has acted reluctant about this project from the beginning. But today he was talking and acting like it was all his idea. I think he was surprised and a little bit impressed with our sound speaker system. In fact, he's a little concerned the bass might be too full. He suggested I turn them around to face the back wall. Go figure!!! 😱
So I have until Aug. 11 to get everything connected and tested. I did a dry connection on all the speaker cables to the amps. I've labeled all of them at each end. Now need to put labels on the speakers. I've left about 8 feet of slack at the amp end to allow us to roll the rack out of the closet and get to the rear for tinkering
We now have electricity in the amp closet. And we have the remote switch that will power up/down the amps when the organ switch is turned on/off. The uninterruptible power supply and the Artisan Sound Engine (actually a computer) will run 24/7. I've got to run an RJ45 network cable from the console pit to the amp rack. And the tech wants a two conductor cable for the remote switch.
I'll be connecting the cables to the speakers this week as I get the last speakers in the speaker chamber I'll connect them and begin performing some adjustments. Need to place the re-enforced upper part on the triangular box. I think the reverberation will be better. I'm also going to mount those Allen Point of Presence speakers on the wall of the pipe chamber. Got more wall space for the mounting brackets with the big pipes gone.
I've got lots to do, but it looks like the advance planning might pay off. But there's always the chance that the light I think I see at the end of tunnel is an oncoming train. 😱
Got Honey-do jobs to do at the house Tues. and Wed. during the day. But I may be able to slip over to the church at night for some work.
I like the plan Oliver has posted for an additional bass box. And I may just try Crown to see if they'll do a custom amp for us. Chutzpa!!! 🙄
Bach On
Sorry, I didn't mean to be rude. Obviously, my English is not so good as I had imagined.
I still don't understand your question. Could you be more specific - what is wrong with the simulations of a loudspeaker boxes? Why do you think that simulations outputs too small boxes and in the reality they should be larger?
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