I need some help, if someone would be so kind...
The background: The response of several ths simulated together is far better than a single one. The horns seem to work together, smoothing the response and reducing the higher frequency ripples. Probably in the same way as other horns add their radiation to a virtual single big horn. My intention is to use several smaller horns distributed over the front wall of my room in order to generate a planar wavefront. The distance should be 1/2 wavelength of the upper crossover frequency. Now i wonder if they are still close enough to make a hornresp simulation as one horn with several drivers realistic.
My question is: How close do they need to be to achieve this effect in reality? Does it work at the 1/2 wavelength distance?
The background: The response of several ths simulated together is far better than a single one. The horns seem to work together, smoothing the response and reducing the higher frequency ripples. Probably in the same way as other horns add their radiation to a virtual single big horn. My intention is to use several smaller horns distributed over the front wall of my room in order to generate a planar wavefront. The distance should be 1/2 wavelength of the upper crossover frequency. Now i wonder if they are still close enough to make a hornresp simulation as one horn with several drivers realistic.
My question is: How close do they need to be to achieve this effect in reality? Does it work at the 1/2 wavelength distance?
i found if u tune a horn really low then the high bass frequency's for the tapped horn become flat with the low ones
im guessing that by adding multiple horns this has a similar effect, it in in theory lowering the cutoff of the horns , by placing them close together so that the mouths act as one bigger mouth
i think thats right, as to your placement i am unsure, will think on/ research it
what will the upper crossover frequency be? and how many horns in what size room?
😕
im guessing that by adding multiple horns this has a similar effect, it in in theory lowering the cutoff of the horns , by placing them close together so that the mouths act as one bigger mouth
i think thats right, as to your placement i am unsure, will think on/ research it
what will the upper crossover frequency be? and how many horns in what size room?
😕
I'll look forward to seeing your pics N-audio, one word of warning, this will be one heavy box! Even tho I made mine from ply (which is lighter than MDF) the driver is at least 10Kg, so put the box into position then bolt the driver in. 🙂
Just a quick question on corner loading, is this correct?
Or should it actually be the other way around firing towards the wall?
Just a quick question on corner loading, is this correct?
An externally hosted image should be here but it was not working when we last tested it.
Or should it actually be the other way around firing towards the wall?
1) MikeHunt79, this direction is right. By facing it to the wall, you will alter the frequency response, since the walls will add a random shaped path to the horn.
2) Regarding my question a few posts earlier, i remembered thomas danleys words, that two sources add perfectly, if they are less then 1/4 wavelength apart. So, if i put two horns 1/2 wl apart, their radiation could add at the low end of the passband, but not at the upper end. am i right?
2) Regarding my question a few posts earlier, i remembered thomas danleys words, that two sources add perfectly, if they are less then 1/4 wavelength apart. So, if i put two horns 1/2 wl apart, their radiation could add at the low end of the passband, but not at the upper end. am i right?
MikeHunt79 said:
Even though the 1/4 wave rule is good, the real question is what to do in the context of a room where there are strong reflections and the room modes dominate. At very low frequency (longest room dimension < half wave) you can put the subs anywhere, as the pressure changes (nearly) in phase everywhere. Higher, around the room modes, the subs will add provided they are at the same antinode (or two antinodes apart for higher order modes - so you can break the 1/4wave rule and still get a reasonable outcome).
Here is a very crude (and not really accurate), 1D, toy example: If your room were 6m long (say), you could put the subs anywhere with respect to frequencies up to ~29Hz. At ~58 Hz subs placed just 3m apart, symmetrical on the long wall, could be cancelling significantly, at a half wave apart.
If practical it might be worth trying various locations and playing swept sines while listening (or, better, measuring) at and around the listening position, probably concentrating on 40Hz up. Strange as it may seem, it can be best to break the symmetry by placing the subs off centre.
I use 3 sources from roughly 50Hz to roughly 70Hz (mains+a reflex sub), 2 sources 35Hz - 50Hz (the TH + the reflex) and 1 source (the TH) below that. This is to try to fill in the modes reasonably well. First attempt at placing these (TH off centre on long wall, reflex in a corner and mains symmetrical on other long wall) worked well enough that I've not tried optimising it (also lack of time).
Ken
mavo
Hello,
it seems you read now my side,
why did´n t you tell us as i posted this effect??
Ruf mich doch mal privat an.
""but I have an idea to improve the tapped horns at the low,
~ 1 oktave, and the size, take two ! one ~1,7 m and one ~2,6 m,
place it so the mouths have a distance, IMO 65 cm, but this can
be different, move them, and connect it parallel, the IMP goes
below ~50 Hz flat 4Ohm, and don´t laugh, the short horn makes
more SPL below 40 Hz!
You can get the effect of bass horn mouth distance and
membran movement cross setting, by partial delete ~ 100 Hz
(mouth distance) may be useful up to ~250 Hz.""
take a 6,5" +8" it is enough for höme listening low inertia.
Hello,
it seems you read now my side,
why did´n t you tell us as i posted this effect??
Ruf mich doch mal privat an.
""but I have an idea to improve the tapped horns at the low,
~ 1 oktave, and the size, take two ! one ~1,7 m and one ~2,6 m,
place it so the mouths have a distance, IMO 65 cm, but this can
be different, move them, and connect it parallel, the IMP goes
below ~50 Hz flat 4Ohm, and don´t laugh, the short horn makes
more SPL below 40 Hz!
You can get the effect of bass horn mouth distance and
membran movement cross setting, by partial delete ~ 100 Hz
(mouth distance) may be useful up to ~250 Hz.""
take a 6,5" +8" it is enough for höme listening low inertia.
Naudio said:
Adding multiple tapped horns together does NOT lower the cutoff. Only your sensitivity goes up. The tapped horn's mouth is so small, you would have to put 20 of them together to even approch a mouth size big enough to get any lowering of the cutoff - which would make it just like a conventional front loaded horn. The whole point of using a tapped horn is to allow for a very under sized mouth. One quick way to prove this is to model it in Hornresp with 1/8 space, 1/4 space, 1/2 space and free space. The thing you should notice is the low cutoff does not change with the different boundry loading, only the sensitivty changes.
Rgs, JLH
That's a useful observation.JLH said:
I wonder if this is in any way connected with Iand's searching for the discrepancy in sensitivity and cone displacement?
kstrain, i try to solve the modal problems of my room and have two strategies in mind. The first one is the one gedlee proposed in the cardioid bass thread - random placement of subs. I posted the second one in the same thread, the double bass array (dba). Both use multiple subs to get a smooth response in the modal range, just like you do. The paper about the dba said, that the subs shall not be placed further away than 1/2 wavelength, which is the point where the first detrimental effects start happening. I browsed the labsub archive and found some posts by tom, indicating that horns add at 1/4 wl and still quite well at 1/3 wl. I would distribute a big th in the form of several small ones over the room. Because of the smaller distance between the subs, i favour this apprach. I will test both and see which is better in my situation.
hm, i didnt refer to your page. i was just referring to the known fact, that acoustic sources placed near each other add their radiation and form a virtual single acoutsic source. You add horns of different size, which i dont want to do. I thought of several 10-12 inch woofers around the room in horns of at least 200 liters each.
JLH, adding more horns change the level of the above passband peaks, which is good for low distortion, because an acoustical lowpass will filter them, just like in a bandpass sub. I agree with your point about tapped horns and this is my main reason to use them, to get lots of acoustic power for relatively small space and money expenses.
hm, i didnt refer to your page. i was just referring to the known fact, that acoustic sources placed near each other add their radiation and form a virtual single acoutsic source. You add horns of different size, which i dont want to do. I thought of several 10-12 inch woofers around the room in horns of at least 200 liters each.
JLH, adding more horns change the level of the above passband peaks, which is good for low distortion, because an acoustical lowpass will filter them, just like in a bandpass sub. I agree with your point about tapped horns and this is my main reason to use them, to get lots of acoustic power for relatively small space and money expenses.
Mavo
thanks, it is ok.
i think the inertia is here in this threat underestimated, specially for home listening.
a left right sub is better as a single one.
but our ear brain system can listen a 40 Hz sound after the 4 wave, the tone is now ~ 100 msec or ~36 m on the run,
take this in relation to the size of your room.
Are there real measurements out there, give me a link please.
thanks, it is ok.
i think the inertia is here in this threat underestimated, specially for home listening.
a left right sub is better as a single one.
but our ear brain system can listen a 40 Hz sound after the 4 wave, the tone is now ~ 100 msec or ~36 m on the run,
take this in relation to the size of your room.
Are there real measurements out there, give me a link please.
AndrewT said:
Changing the loading doesn't affect the cone displacement to any significant extent, just the sensitivity.
The simulations vs. Tom's measurements for the TH-115 were both exactly comparable -- a single box in the middle of a car park is as close as you can get to 2pi loading...
Ian
aceinc said:
1) AFAIK a very large/long compression horn tuned to at least an octave below the desired flat BW is required and as long as you don't try to fold it up too much it won't be a complex build, just expensive. Or you can slice it up into multiples to shorten it with the trade-off of using more drivers.
2) Spec-wise, the Titanic is the 'no-brainer' since it has more dynamic headroom potential, though any high excursion/power handling driver not designed for either high performance car audio or prosound apps may not do well distortion-wise when pushed hard in a compression horn alignment, so as always YMMV.
FWIW, of the drivers I've simmed, the MTX 9515-04 would be at the top of my short list if only one sub is the game plan.
Not familiar with the Rythmik's sub driver, but TD's type of servo motor driven drivers used in the BT-7 and Contrabass systems are as good as it gets AFAIK.
GM
GM said:
Can anybody confirm how close the published specs of this driver are to the actual specs?
Hello,
"Adding multiple tapped horns together does NOT lower the cutoff. "
if you use membran movement cross setting and bass horn mouth distance it worked:
By parallel wiring the two different horns, the driver of the long horn controlled
the stroke of the driver in the short horn, the little horn goes not in the
acoustic short circuit, but creates sound pressure, amazing here, more pressure
as the long horn below 40 Hz. At the same time, the impedance peak of the lowest
octave eliminated by non-entanglement, below 50 Hz ~ 4 ohms.
See system horn mouth measurement and single simulation of the KORNETT.
"Adding multiple tapped horns together does NOT lower the cutoff. "
if you use membran movement cross setting and bass horn mouth distance it worked:
By parallel wiring the two different horns, the driver of the long horn controlled
the stroke of the driver in the short horn, the little horn goes not in the
acoustic short circuit, but creates sound pressure, amazing here, more pressure
as the long horn below 40 Hz. At the same time, the impedance peak of the lowest
octave eliminated by non-entanglement, below 50 Hz ~ 4 ohms.
See system horn mouth measurement and single simulation of the KORNETT.
using a single driver and a straight horn, how many octaves can one get from this set up?GM said:
Tapped horn actual measurement
Has anyone measured the actual frequency response for tapped horn? Is it near the simulation made by hornresp or akabak?
Has anyone measured the actual frequency response for tapped horn? Is it near the simulation made by hornresp or akabak?