Don Snyder_Single_v_Double Taper
Hi Don,
Thanks for the Single/Double example. One of the reasons I like the double taper horn flare is, that it makes it easier for me to model a horn with the driver in the middle of the mouth flare section (see: LIVE SOUND Specific Tapped Horn thread, Post #349 and #350 - not an isobaric arrangement, in #349 I'm just showing the different speaker directions, #350 shows how to use two boxes together - or one big dual (quad) box,etc.). I find that particular lay-out very adaptable to different length, cross-sections and numbers of speakers. Attached one more 3015LF/double flare/486 liter model.
Regards,
Hi Don,
Thanks for the Single/Double example. One of the reasons I like the double taper horn flare is, that it makes it easier for me to model a horn with the driver in the middle of the mouth flare section (see: LIVE SOUND Specific Tapped Horn thread, Post #349 and #350 - not an isobaric arrangement, in #349 I'm just showing the different speaker directions, #350 shows how to use two boxes together - or one big dual (quad) box,etc.). I find that particular lay-out very adaptable to different length, cross-sections and numbers of speakers. Attached one more 3015LF/double flare/486 liter model.
Regards,
Attachments
I have...freddi said:
You can actually feel the bass vibrate the opposing side aluminum bleachers...
The one really great thing about TH's for PA that you actually have to hear to appreciate, is directionality of bass. Hornresp just doesn't give you that bit of information. They don't have to be ear bleeding loud up close to project at distance. It would have taken me, I'm guessing, in the neighborhood of a dozen or more double 15's and a power alley, to be able to get this kind of bass at distance, and then I'd be killing the home side.
I don't have the system set up for maximum 'chest thump' in the 100-160hz range, rather I have it set up for maximum 40-60hz 'feel' It changes the entire system from sounding PA to sounding HT..... outdoors.
Vibrating the opposing bleachers... off of a single 20amp circuit with only 4 TH cabinets... now that's cool.
My thanks to Tom, Mike, Davey, Syd, Don and others... TH allowed me to have big system sound, on a very limited school budget.
Dual taper
I had a quick experiment with dual taper also, it does appear to give you a few extra DB's at the expense of a small amount of low end extension. A worthwhile tradeoff if you ask me.
Dual taper is black, grey is single taper:
Single taper (248L)
Dual taper (248L)
250L is about the biggest I can go and I've gone for 40Hz as I'm planning to use this for PA. I think this box will perform well, I've simmed it with the Ciare 12.00 SW and it also works well and gives out more output as it has over twice the xmax of the Definimax 4012, so I can switch drivers if I need more output.
This thing will be almost 5ft tall unfolded tho, so I'll see if I can work out a single fold box, and I may even have a go at building it if I get time!
Anyone tried the Autocad method for folding TH's?
I had a quick experiment with dual taper also, it does appear to give you a few extra DB's at the expense of a small amount of low end extension. A worthwhile tradeoff if you ask me.
Dual taper is black, grey is single taper:
An externally hosted image should be here but it was not working when we last tested it.
Single taper (248L)
An externally hosted image should be here but it was not working when we last tested it.
Dual taper (248L)
An externally hosted image should be here but it was not working when we last tested it.
250L is about the biggest I can go and I've gone for 40Hz as I'm planning to use this for PA. I think this box will perform well, I've simmed it with the Ciare 12.00 SW and it also works well and gives out more output as it has over twice the xmax of the Definimax 4012, so I can switch drivers if I need more output.
This thing will be almost 5ft tall unfolded tho, so I'll see if I can work out a single fold box, and I may even have a go at building it if I get time!
Anyone tried the Autocad method for folding TH's?
Re: Re: Dual taper
http://users.bigpond.net.au/ggoodacre/centauri/diy/hornfold.html
The example is with a FLH but I think with a little tweaking it would work for TH's.
Here's the autocad method:just a guy said:
http://users.bigpond.net.au/ggoodacre/centauri/diy/hornfold.html
The example is with a FLH but I think with a little tweaking it would work for TH's.
Re: Dual taper
You can use some of the volume saved by the dual taper to make the first section of the horn slightly longer, this will then give the same LF cutoff as the single taper but still have higher efficiency.
Ian
MikeHunt79 said:I had a quick experiment with dual taper also, it does appear to give you a few extra DB's at the expense of a small amount of low end extension. A worthwhile tradeoff if you ask me.
Dual taper is black, grey is single taper:
An externally hosted image should be here but it was not working when we last tested it.
250L is about the biggest I can go and I've gone for 40Hz as I'm planning to use this for PA. I think this box will perform well, I've simmed it with the Ciare 12.00 SW and it also works well and gives out more output as it has over twice the xmax of the Definimax 4012, so I can switch drivers if I need more output.
This thing will be almost 5ft tall unfolded tho, so I'll see if I can work out a single fold box, and I may even have a go at building it if I get time!
Anyone tried the Autocad method for folding TH's?
You can use some of the volume saved by the dual taper to make the first section of the horn slightly longer, this will then give the same LF cutoff as the single taper but still have higher efficiency.
Ian
Looks like you're loosing 3 Hz to gain 2dB. Iand's suggestion to:
"...use some of the volume saved by the dual taper to make the first section of the horn slightly longer, this will then give the
same LF cutoff as the single taper but still have higher efficiency."
If we reduce the height at the center, then use the saved height to increase the mouth, we don't have any saved height left to
lengthen the horn.
Sorry guys, you can't have it both ways.
~Don
"...use some of the volume saved by the dual taper to make the first section of the horn slightly longer, this will then give the
same LF cutoff as the single taper but still have higher efficiency."
If we reduce the height at the center, then use the saved height to increase the mouth, we don't have any saved height left to
lengthen the horn.
Sorry guys, you can't have it both ways.
~Don
That's true Don...
given a design if you wanted some extra bass it becomes easy to decide which method to choose though. To increase the length of the first half of the horn will add less bulk than to increase the size of the mouth. I think that was perhaps the the direction that the idea was going. Either way the box has to get larger so as you said no free lunch.
What about Tom Danley's trick of using the nonlinearity of air to make using a smaller mouth work to your advantage as in the B-deap design? Just a thought. I don't understand the math so I can't comment but it looks interesting.
given a design if you wanted some extra bass it becomes easy to decide which method to choose though. To increase the length of the first half of the horn will add less bulk than to increase the size of the mouth. I think that was perhaps the the direction that the idea was going. Either way the box has to get larger so as you said no free lunch.
What about Tom Danley's trick of using the nonlinearity of air to make using a smaller mouth work to your advantage as in the B-deap design? Just a thought. I don't understand the math so I can't comment but it looks interesting.
Using MikeHunt's HornResp input parameters, I compared the straight version to a modified bent version, changing:
L23 add 10
L34 add 10
S4 cut 176
S5 cut 295
Now F3 matches between the two versions, and the volume is reported at 248, but the SPL is less than one dB different.
Did we gain anything?
~Don
P.S. grey line is single taper, black is dual taper lengthened.
L23 add 10
L34 add 10
S4 cut 176
S5 cut 295
Now F3 matches between the two versions, and the volume is reported at 248, but the SPL is less than one dB different.
Did we gain anything?
~Don
P.S. grey line is single taper, black is dual taper lengthened.
Attachments
Don Snyder said:
The dual taper has about 2dB less ripple in the lower passband.
This is a better way to reduce ripple than adding a series inductor, which is often suggested (but which increases loss and distortion).
And as I said, if the TH is folded into 4 it comes free, so I don't see what the big objection is.
Ian
Don Snyder said:
I'm not convinced it's so difficult - given David's wonderful Tapped Horn Wizard -- to come up with a double tapered TH that's better than a single tapered one of the same volume in only a few minutes. So long as you allow for the length round the bends, at 100Hz or less the exact profile isn't so critical -- in fact as Tom showed you can even make a TH out of stepped sections so long as the overall taper approximated to the desired one.
Obviously you need a folding plan that works with a double taper, but ones like the TH115 or TH212 will do just fine. You might need to go back and adjust the point at which the taper changes after trying a folding plan (it's unlikely to be exactly half-way along) but the response isn't that sensitive to the exact point of this, about half-way along or even a bit closer to the mouth seems to work fine.
And it does seem to be effective at getting rid of (or at least reducing) that pesky first dip that many drivers in a TH suffer from unless you add series inductance, with all the problems that result from this.
Ian
Re: Re: Dual taper
Thanks for the info guys, this dual taper definitely has benefits with a little experimentation.
New dual taper parameters:
Grey = single taper (248L), Black = dual taper (246L).
I'm shooting for 40Hz extension, so you would think the single taper would beat the dual taper and it does but this isn't that much of an issue because...:
Again, Grey = single taper (248L), Black = dual taper (246L).
The exursion plots are very similar, and because there so little cone displacement at 40Hz, the dual taper box actually has no problem giving out plenty of 40Hz as it's not longer xmax limited and instead power limited. I'm guessing the longer path length of the dual taper allows the low excursion part to go lower the the first peak in the SPL graph maybe?
I've found with a driver like the Definimax 4012 you're xmax limited a lot of the time. Even the Ciare 12SW with 11.5mm of xmax can run out when running higher power... In theory with the dual taper design I can just just as much output at 40Hz as I can at 50Hz with a little EQ and a little extra power from the amp.
I've thought about drawing a non-folded version first, then try and fold it after checking the widths as you go... Easier said than done.
The tweaked dual taper box looks to have good output to 200Hz, am I right in thinking folding acts as a 100Hz LPF? If this is the case I think maybe a non-folded design would be easier and also better performing...
Thanks for the info guys, this dual taper definitely has benefits with a little experimentation.
Yep I've found extending the path has benefits, I've done a little tweaking, throat, length and many things have changed (box volume is almost the same tho).iand said:
New dual taper parameters:
An externally hosted image should be here but it was not working when we last tested it.
Grey = single taper (248L), Black = dual taper (246L).
An externally hosted image should be here but it was not working when we last tested it.
I'm shooting for 40Hz extension, so you would think the single taper would beat the dual taper and it does but this isn't that much of an issue because...:
Again, Grey = single taper (248L), Black = dual taper (246L).
An externally hosted image should be here but it was not working when we last tested it.
The exursion plots are very similar, and because there so little cone displacement at 40Hz, the dual taper box actually has no problem giving out plenty of 40Hz as it's not longer xmax limited and instead power limited. I'm guessing the longer path length of the dual taper allows the low excursion part to go lower the the first peak in the SPL graph maybe?
I've found with a driver like the Definimax 4012 you're xmax limited a lot of the time. Even the Ciare 12SW with 11.5mm of xmax can run out when running higher power... In theory with the dual taper design I can just just as much output at 40Hz as I can at 50Hz with a little EQ and a little extra power from the amp.
I too have been struggling with trying to get my head around how to do a folded dual taper box... Volvotrear's spreadsheet is great for single taper boxes but won't work for dual taper.Don Snyder said:
I've thought about drawing a non-folded version first, then try and fold it after checking the widths as you go... Easier said than done.
The tweaked dual taper box looks to have good output to 200Hz, am I right in thinking folding acts as a 100Hz LPF? If this is the case I think maybe a non-folded design would be easier and also better performing...
Hi MikeHunt,
I'm long on geometry, but short on intuition. Tom Danley knows how much you can fudge, and he cranked out the fold on the
LabSub in a week. Thats 10x harder than a double taper tapped horn like yours. The LabSub is an 8 taper horn.
If you like, I'll take a crack at your latest this week.
~Don
P.S. take a look at the Beyma 12LX60. Some guys in Germany are using it.
I'm long on geometry, but short on intuition. Tom Danley knows how much you can fudge, and he cranked out the fold on the
LabSub in a week. Thats 10x harder than a double taper tapped horn like yours. The LabSub is an 8 taper horn.
If you like, I'll take a crack at your latest this week.
~Don
P.S. take a look at the Beyma 12LX60. Some guys in Germany are using it.
