buggsson said:
Absolutely, I am allready having fun preparing, and rather sooner than later, I hope, I will start building.
MaVo, I didn't realise the differences I was looking for was that subtle, but now I can see what you are driving at. My problem is that I don't master the tech. talk as yet, so I have a problem realising which driver has a stiffer suspension than a comparable driver. How do you define a stiffer suspension?
Regarding large Xmax, what is large Xmax, one way, or to put it differently, I guess there will be a minimum value for Xmax that it would be unwise to go lower than for inclusion in a TH? I've put 9 mm as my own lower limit.
I will let go now, in my quest for the suitable driver, if I only can get a grip on the stiffness issue. I is high time to get started with Hornresp, and we don't like each other much
My 40Hz tapped horns have no problem keeping up with my 108dB mid-bass horns. The tapped horns are loaded with B&C Speakers 8PE21 woofers. They reach their quoted Xmax with 2.5 Watts, which equals 104dB. They reach Xmech at 48 Watts, which equals about 117dB. Needless to say, this little 8" woofer is real mean in a tapped horn. I would advise you don't approch your design with fixed numbers in your head. Just start modeling it and see where the results lead you. You will be surprised what you can get out of a tapped horn. Do you really need more than 120dB in a home setting?
Rgs, JLH
Re: David have you seen....
Hi Moray,
Sorry, I missed noting that your query was directed specifically to me. As indicated in my reply to your e-mail, the designs shown in figures 1 and 2 of the Klayman patent document cannot be modelled in Hornresp. It would be necessary to use AkAbak if you wish to check their performance. I suspect it will be not much different to that of a conventional tapped horn, though.
Kind regards,
David
moray james said:
Hi Moray,
Sorry, I missed noting that your query was directed specifically to me
. As indicated in my reply to your e-mail, the designs shown in figures 1 and 2 of the Klayman patent document cannot be modelled in Hornresp. It would be necessary to use AkAbak if you wish to check their performance. I suspect it will be not much different to that of a conventional tapped horn, though.Kind regards,
David
JLH said:
?
I thought 8PE21 is a midrange.
http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=294-652
problem is, im 20 and have no way to make money, i have wanted to start a business building sound systems for a while, for home and pa
i know a small local club who are interested in buying a few tapped horn 40hz bass bins, so this looks like a good start for me
i think i should ask tom if he minds, or maybe i should design some conventional horns, but these are bigger
it does seem unfair though, i need toms email so i can ask, maybe he will hire me to spread his market to england (if its not here already)
or i could say the product uses his technology, but doesn't represent it, that way if people like what they see, they can go to him for real deal applications like large clubs/concerts
anyone have his addy?
i do know another company that uses his technology, but just say its his, or maybe i can pay him to use it, who knows
i know a small local club who are interested in buying a few tapped horn 40hz bass bins, so this looks like a good start for me
i think i should ask tom if he minds, or maybe i should design some conventional horns, but these are bigger
it does seem unfair though, i need toms email so i can ask, maybe he will hire me to spread his market to england (if its not here already)
or i could say the product uses his technology, but doesn't represent it, that way if people like what they see, they can go to him for real deal applications like large clubs/concerts
anyone have his addy?
i do know another company that uses his technology, but just say its his, or maybe i can pay him to use it, who knows
it is, and only has 1mm xmax
u should have used this its cheeper and has a 5mm xmax
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=294-654
maybe he had his reasons, or maybe he made a mistake, who knows
could u post up the imput info for this little horn, thanks
my horns almost done, just needs paint, its class, will upload pics tonight
u should have used this its cheeper and has a 5mm xmax
http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=294-654
maybe he had his reasons, or maybe he made a mistake, who knows
could u post up the imput info for this little horn, thanks
my horns almost done, just needs paint, its class, will upload pics tonight
CLS said:
That is the beauty of horns, you don’t need large Xmax to create high SPL. A horn is an acoustical transformer which transformers the speaker’s high acoustical impedance so it can more efficiently couple to the air. The sensitivity of my 40Hz tapped horn is 100dB 1W/1M in ¼ space. I only needed to cover from 40Hz to 80Hz with a max SPL of 115dB with this tapped horn. I exceeded the goal by 2dB (117dB with 48 Watts in & at Xmech) with the 8PE21. It is no mistake using the 8PE21. Additionally, since it isn’t being used for the critical mid-range, the Xmax specs are only guidelines and not hard rules. If I run it full range without a crossover, it is amazingly clean sounding up into the vocal range due to the woofer’s very close proximity to the mouth. It is also easy to hear the Doppler induced distortion once the woofer really starts to stroke. However, since we are only talking about bass frequencies, the distortion in this region stays surprisingly low until the woofer approaches the very edge of Xmech. Guidelines – they are only guidelines.
Another thing you guys are forgetting is the air mass inside of the horn will damped the woofer cone and lower Fs by as much as a factor of 3. So, in my 40Hz tapped horn, the Fs of the 8PE21 drops to 28Hz. I measured this, and Hornresp accurately predicted it in the electrical impedance screen.
Rgs, JLH
Naudio said:
Here is the input data for my 40Hz tapped horn.
Here is the SPL graph with 1 watt input.
Notice that these are special order 16 ohm versions of the 8PE21 – Notice the model number on the back plate “8PE21-16” the “-16” means 16 ohms.
The 40Hz tapped horns were designed to fill in below these tractrix mid-bass horns.
Rgs, JLH
Naudio said:problem is, im 20 and have no way to make money, i have wanted to start a business building sound systems for a while, for home and pa
i know a small local club who are interested in buying a few tapped horn 40hz bass bins, so this looks like a good start for me
i think i should ask tom if he minds, or maybe i should design some conventional horns, but these are bigger
it does seem unfair though, i need toms email so i can ask, maybe he will hire me to spread his market to england (if its not here already)
or i could say the product uses his technology, but doesn't represent it, that way if people like what they see, they can go to him for real deal applications like large clubs/concerts
anyone have his addy?
i do know another company that uses his technology, but just say its his, or maybe i can pay him to use it, who knows
Yorkville Sound is licensed to use the patented technology of the tapped horn. That means they signed a contract and pay to gain the rights to use the tapped horn technology. It is very easy to contact Danley Sound Labs. Just go to their Web site and e-mail them and ask them about a licensing agreement. A will forewarn you, a licensing agreement will not be cheap. In addition, it will not be solely up to Tom whether or not to grant permission to build tapped horns without a license. I will also tell you up front that there is no way they would allow you to build tapped horns for a profit without a licensing agreement. If they made an exception for you, then it would open up a legal loophole that would allow others to do the same. The short of the matter is – No.
Hi there,
i want to make some changes to my system and maybe you could help me with it.
First the background: I decided to change my offset driver horns from 3 way to 2 way. I do this in order to place the woofers around the room for a smoother response in the modal area. My design goals are to have low extension, usable spl and a high frequency corner in the 100-200hz area for crossover to the horns. As i am stuck on the drivers, which are four Beyma 12P1000ND, i have to make them work in this setup. I want to use them in tapped horns. I can design digital EQ for them and use steep filters, so i have an additional degree of freedom here.
I have added a picture of the design, which seems to be the best tradeoff.
My questions are:
- Is there something wrong with this setup?
- How can i improve it?
- The horn is quite long. With a 3 fold, 4 segment horn, as posted on volvotreters homepage, i end up with a pathlength of each segment of about 160cm. Does the 1/2 WL resonance of around 100hz mess up the frequency response?
- The efficiency rises with frequency and the acousstic lowpass is quite high. I tried making it lower, but did not find a way to achieve this, so i made it maximally flat instead. Does this make the distortions stand out too much?
Thanks, if you made it this far. Maybe you even post a reply
i want to make some changes to my system and maybe you could help me with it.
First the background: I decided to change my offset driver horns from 3 way to 2 way. I do this in order to place the woofers around the room for a smoother response in the modal area. My design goals are to have low extension, usable spl and a high frequency corner in the 100-200hz area for crossover to the horns. As i am stuck on the drivers, which are four Beyma 12P1000ND, i have to make them work in this setup. I want to use them in tapped horns. I can design digital EQ for them and use steep filters, so i have an additional degree of freedom here.
I have added a picture of the design, which seems to be the best tradeoff.
My questions are:
- Is there something wrong with this setup?
- How can i improve it?
- The horn is quite long. With a 3 fold, 4 segment horn, as posted on volvotreters homepage, i end up with a pathlength of each segment of about 160cm. Does the 1/2 WL resonance of around 100hz mess up the frequency response?
- The efficiency rises with frequency and the acousstic lowpass is quite high. I tried making it lower, but did not find a way to achieve this, so i made it maximally flat instead. Does this make the distortions stand out too much?
Thanks, if you made it this far. Maybe you even post a reply
Attachments
MaVo: Beyma, 3 v. 4 section TH
Hi MaVo: When I typed your values into Hornresp I got the same SPL response that you did. When I changed it into a 4 section TH the SPL response and the system volume changed quite a bit. I cannot find anything wrong with my input data, maybe you can take a look at it, or is there a problem in Hornresp?
Hi MaVo: When I typed your values into Hornresp I got the same SPL response that you did. When I changed it into a 4 section TH the SPL response and the system volume changed quite a bit. I cannot find anything wrong with my input data, maybe you can take a look at it, or is there a problem in Hornresp?
Attachments
MaVo said:Hi there,
i want to make some changes to my system and maybe you could help me with it.
First the background: I decided to change my offset driver horns from 3 way to 2 way. I do this in order to place the woofers around the room for a smoother response in the modal area. My design goals are to have low extension, usable spl and a high frequency corner in the 100-200hz area for crossover to the horns. As i am stuck on the drivers, which are four Beyma 12P1000ND, i have to make them work in this setup. I want to use them in tapped horns. I can design digital EQ for them and use steep filters, so i have an additional degree of freedom here.
I have added a picture of the design, which seems to be the best tradeoff.
My questions are:
- Is there something wrong with this setup?
- How can i improve it?
- The horn is quite long. With a 3 fold, 4 segment horn, as posted on volvotreters homepage, i end up with a pathlength of each segment of about 160cm. Does the 1/2 WL resonance of around 100hz mess up the frequency response?
- The efficiency rises with frequency and the acousstic lowpass is quite high. I tried making it lower, but did not find a way to achieve this, so i made it maximally flat instead. Does this make the distortions stand out too much?
Thanks, if you made it this far. Maybe you even post a reply
You don’t need simulated/modeled response flat to 20Hz in order to get it in your room. Room gain will naturally boost the low frequencies. The rule of thumb is it will boost at +6dB per octave when the longest dimension of your room is half a wavelength. So if your room’s longest dimension is 5.5 meters/18Ft. boost would get rolled in around 32Hz. Response would be +6dB at 16Hz, +4dB at 20Hz, and +3dB at 24Hz. In my personal experience, the room gain effect has been more than this. Provided you have an average sized room, I find shooting for around 27Hz (+/- 2Hz) nets me 20Hz response in most rooms. Having a falling response at the low end can actually help keep the bass response in the room level. You can always EQ down the response, but why don’t you let your room work for you. It will result in a smaller horn that still achieves its goals.
I would also advise you don’t try using a tapped horn up in the peaky high frequency range. Basically we are trading bandwidth for a smaller package. The trade is well worth it to me. Every time I have tried to stretch the performance of something, it has always backfired on me. Use it where it is intended. If you need coverage up to 200Hz, then build a couple smaller tapped horns, or a conventional front loaded mid-bass horn. Although, I would personally try to avoid using any kind of folding in a horn above 80Hz.
Rgs, JLH
I just noticed something interesting. Not sure if everyone already knows this but...
Using hornresp, a tapped horn with the tap at the very beginning and end of the line results almost identical results as a simple end loaded tl (by selecting "no" when prompted if you want to model a tapped horn, and make sure to look at the COMBINED response of driver and mouth). You have to look very close to see any difference at all, and diaphragm displacement, etc is all the same. As far as I can tell, hornresp says there is no noticeable difference between an end loaded tl and a tapped horn with the tap at the very beginning and very end.
Of course you can move the driver to the most optimal position in a tapped horn, but you can also do that in a tl. But even with the driver in optimal position in a tapped horn, the benefits seem to be almost negligible compared against an end loaded tl.
Just as an example, this is JLH's design from a couple of posts ago, exactly the same input parameters but select "no" when asked if you want to model a tapped horn, then view the combined driver and mouth response. It's slightly different than the tapped version posted above, but really not much. And more importantly, driver displacement is nearly identical. Both the tapped horn and the end loaded tl can be tweaked in various methods to provide a smoother response and thus more usable bandwidth.
JLH's tapped horn is just one example, only used because it was on this page. I've gone through a few other examples posted here on previous pages and it seems to be a theme that these tapped horns model very similar to end loaded tl's whose boxes are identical except for driver location.
Anyway, JLH has a nicer looking graph overall, but the point is that driver displacement and sensitivity in the tapped horn vs tl in this example are ~ equal, so max spl is also ~ equal. No huge advantage to the tapped horn, in other words.
Interesting, yes? No?
Using hornresp, a tapped horn with the tap at the very beginning and end of the line results almost identical results as a simple end loaded tl (by selecting "no" when prompted if you want to model a tapped horn, and make sure to look at the COMBINED response of driver and mouth). You have to look very close to see any difference at all, and diaphragm displacement, etc is all the same. As far as I can tell, hornresp says there is no noticeable difference between an end loaded tl and a tapped horn with the tap at the very beginning and very end.
Of course you can move the driver to the most optimal position in a tapped horn, but you can also do that in a tl. But even with the driver in optimal position in a tapped horn, the benefits seem to be almost negligible compared against an end loaded tl.
Just as an example, this is JLH's design from a couple of posts ago, exactly the same input parameters but select "no" when asked if you want to model a tapped horn, then view the combined driver and mouth response. It's slightly different than the tapped version posted above, but really not much. And more importantly, driver displacement is nearly identical. Both the tapped horn and the end loaded tl can be tweaked in various methods to provide a smoother response and thus more usable bandwidth.
An externally hosted image should be here but it was not working when we last tested it.
JLH's tapped horn is just one example, only used because it was on this page. I've gone through a few other examples posted here on previous pages and it seems to be a theme that these tapped horns model very similar to end loaded tl's whose boxes are identical except for driver location.
Anyway, JLH has a nicer looking graph overall, but the point is that driver displacement and sensitivity in the tapped horn vs tl in this example are ~ equal, so max spl is also ~ equal. No huge advantage to the tapped horn, in other words.
Interesting, yes? No?
JLH said:
Here is a bigger screen shot of the tapped horns. This is for the $40 Coustic car subwoofer.
Here is the one for the $50 MTX car subwoofer.
Have fun.
In Post #1698 the Coustic driver seemed to model reasonably well. It also seems inexpensive which is a plus.
Are there any negatives for this as a first TH project?
In one of the previous post someone mentioned that having a length equivalent to 1/2 wavelength of one of the higher frequency peaks would cause the peak to be reduced in amplitude. How hypothetical is this? In other words should I base my design around this?
If so I need at least one length of 83" to take care of the 80Hz peak. What reduction in amplitude can I expect?
If I do not need an 83" length, I could potentially fold this a bit more. What I am trying to do at this point is wrap my mind around a design that can be incorporated into the decor and gain waf. (What good is the best sounding sub in the world if I can only play it on the back porch)
Any help with some folding options would be great.
Paul
Mavo I don't think you got my point, but maybe you did.
Anyway, the point was that hornresp says you can take any folded pipe regardless of taper and it makes no difference if you mount the driver on the outside baffle (end loaded tl) or on the inside divider (tap at 0 and 100 percent of line length). No difference in frequency response or cone movement at all and therefore no difference in max spl. (This is only true with the driver right at the end of the line - moving it down the line changes response a bit, but not sensitivity, so the tapped horn really doesn't load a line any better than a tl.)
I found that surprising.
Anyway, the point was that hornresp says you can take any folded pipe regardless of taper and it makes no difference if you mount the driver on the outside baffle (end loaded tl) or on the inside divider (tap at 0 and 100 percent of line length). No difference in frequency response or cone movement at all and therefore no difference in max spl. (This is only true with the driver right at the end of the line - moving it down the line changes response a bit, but not sensitivity, so the tapped horn really doesn't load a line any better than a tl.)
I found that surprising.
aceinc said:
- I think it looks nice.
- The flare rate of the section modifies the resonance frequency. 1/2 WL only works for straight pipes. You would have to do this by trial and error.
- The reduction would probably be a near complete cancellation, just like with the first order room mode. But it will probably have a lower q than the peak, resulting in a deep notch at this frequency.
- If you want to filter the notches, better use a pvc pipe with stuffing, like in the dts 20, so you can adjust frequency, q and reduction.
- Have a look at http://www.volvotreter.de/downloads/Folding_a_Tapped_Horn.pdf for a folding scheme.
aceinc said:
Aceinc,
I really don’t see any reason why the Coustic woofer wouldn’t make for a good first tapped horn project. I would prefer a paper cone, but since the poly cone has good mass, it should be pretty tough. I must also make sure you know that this tapped horn only exists as a simulation – I have not built it.
After building and measuring my 40Hz horns, the ½ wavelength cancellation trick does not appear to work very well with tapped horns. On the other hand, it works all too well with conventional front loaded horns. With a front loaded horn you can actually get the thing to act as a notch filter. Folds normally work quite well as mufflers. However, it does not work so well with tapped horns due to the woofer’s close proximity to the mouth. All the sound coming from the back side of the cone it very audible. Don’t forget there are two sides to a cone.
A good low pass filter of at least 24dB/Oct is recommended. So, don’t base your design off of the ½ wavelength trick. It doesn’t work as well as it should.Rgs, JLH