Testing Question
When comparing my single 15 TH prototypes against a Double 15 cabinet what voltage sould I use for the double 15?
I have a cabinet that looks like it will work.
At 28.3v it keeps up with and surpasses at 45hz the double 15 JBL if the double 15 is getting 14.2v. If this is correct, then I'm good. (Modded 2225H's, coated for lower F).
If not, at 28.3v to the double 15 there is no way the TH will keep up. I'm not able to test full power, but I assume the TH will go louder at full power than the double 15.
The goal was to meet or surpass my double 18's (sold), and my JBL double 15's with a single driver cabinet so I can run 2-3 per amp side vs only 1 double per side.
Test are indoors in 5,000 sq ft. Will test outside this week.
Thanks.
When comparing my single 15 TH prototypes against a Double 15 cabinet what voltage sould I use for the double 15?
I have a cabinet that looks like it will work.
At 28.3v it keeps up with and surpasses at 45hz the double 15 JBL if the double 15 is getting 14.2v. If this is correct, then I'm good. (Modded 2225H's, coated for lower F).
If not, at 28.3v to the double 15 there is no way the TH will keep up. I'm not able to test full power, but I assume the TH will go louder at full power than the double 15.
The goal was to meet or surpass my double 18's (sold), and my JBL double 15's with a single driver cabinet so I can run 2-3 per amp side vs only 1 double per side.
Test are indoors in 5,000 sq ft. Will test outside this week.
Thanks.
screamersusa, did you check this thread http://www.diyaudio.com/forums/showthread.php?s=&threadid=130967&pagenumber=1
screamersusa, 28.3Volts to the TH with a single 3015LF is 100watts since it is an 8 ohm load. For the double 15s (assuming the drivers are wired in parallel) you should feed it 20Volts which will be 100watts in a 4 ohm load.
djk's design of a TH for the 3015LF (which I pointed to in my previous post) should reach the same SPL levels as a double 15 using the same drivers in a ported cab.
djk's design of a TH for the 3015LF (which I pointed to in my previous post) should reach the same SPL levels as a double 15 using the same drivers in a ported cab.
Thanks Samuel and lilltemike.
I have that DJK post saved. Working on it.
Also I would re-look at reflectors.
In my current test, adding a larger smoother angle reflector to the original 8x8 45 degree one, added 1 db all around.
Makes some sense as they should really be looked at as DEflectors. If you bounce the sound away at an angle instead of Straight BACK, there is a difference, or multiple differences at multiple frequencies as standaing waves occur. I may be nuts but I hear and see a difference.
The previous box was vary complex and tested great above 50hz.
While It didn't go low enough, it sounded really nice and clear. Lots of angles and no parrallel surfaces. That was the artsy one
built by feel. Sounded the best quality wise of all the boxes I've built the last two weeks. About 103 db from 120-50 I just couldn't get 40 hz at 98db out of it.
The parallel walled ones seem a touch muddy.
I have that DJK post saved. Working on it.
Also I would re-look at reflectors.
In my current test, adding a larger smoother angle reflector to the original 8x8 45 degree one, added 1 db all around.
Makes some sense as they should really be looked at as DEflectors. If you bounce the sound away at an angle instead of Straight BACK, there is a difference, or multiple differences at multiple frequencies as standaing waves occur. I may be nuts but I hear and see a difference.
The previous box was vary complex and tested great above 50hz.
While It didn't go low enough, it sounded really nice and clear. Lots of angles and no parrallel surfaces. That was the artsy one
built by feel. Sounded the best quality wise of all the boxes I've built the last two weeks. About 103 db from 120-50 I just couldn't get 40 hz at 98db out of it.
The parallel walled ones seem a touch muddy.
Hi everyone.
I've been looking at this thread for days and I'd like to ask for some help.
1. Where is it said what qualities make a driver a good choice for a tapped horn?
and
2. Where do I find the guidelines to work out what the optimum BW, SPL and f3 to stay near for a given driver?
I know I can get on hornresp with any driver and create any response but it doesn't feel right. It's as if it wouldn't sound as good if I tried to get a driver to do something that wasn't within a certain range of what's reasonable? Is that right?
Thanks for any help.
I've been looking at this thread for days and I'd like to ask for some help.
1. Where is it said what qualities make a driver a good choice for a tapped horn?
and
2. Where do I find the guidelines to work out what the optimum BW, SPL and f3 to stay near for a given driver?
I know I can get on hornresp with any driver and create any response but it doesn't feel right. It's as if it wouldn't sound as good if I tried to get a driver to do something that wasn't within a certain range of what's reasonable? Is that right?
Thanks for any help.
G'day Allen
Lovely part of the world you're from.
Look for a driver with an Fs ~ 1.5x your target LF cutoff. Midrange Qe will help too. You will achieve ~2 octaves of bandwidth. Hornresponse is your friend. Let it guide you. If you like your Hornresponse model, and you build as modelled, you will have a good result.
Cheers
William Cowan
Lovely part of the world you're from.
Look for a driver with an Fs ~ 1.5x your target LF cutoff. Midrange Qe will help too. You will achieve ~2 octaves of bandwidth. Hornresponse is your friend. Let it guide you. If you like your Hornresponse model, and you build as modelled, you will have a good result.
Cheers
William Cowan
@ Screamers
Interesting. Do you have pics or a diagram as to where you placed them so I can have a better idea of the changes you made and the results you observed?
I'm still on the steep part of the learning curve too. Thanks for your detailed posts as you muddle along with the rest of us.
Interesting. Do you have pics or a diagram as to where you placed them so I can have a better idea of the changes you made and the results you observed?
I'm still on the steep part of the learning curve too. Thanks for your detailed posts as you muddle along with the rest of us.
I think I'm about as good as I can get with a 3015 in a simple box.
Jbell sent me the 24x24x48 box, I whipped one up and also discovered it would fit in the 34x34x21 bulldog so I modded that one as well. The wonders of styrofoam modeling
They seemed to test about the same so I went with the 34x34x21 Bulldog vs the 40x28x21 PATH15 I was working on.
This way I was comparing two boxes I might actually use.
Listening to the two, the Bulldog sounded angrier and roared.
The Path15 sounded flatter. The bulldog seemed to want more power to achieve a good level. Testing revealed the PATH15 was actually the better box. It beat the Bulldog by about 3 db all around except at 60 and 50 where the Bulldog was 1 and two db hotter respectively. The ran neck and neck at 45 and 40 with the PATH15 4 db hotter at 38hz. Unlike the bulldog, the PATH is full of screw holes and air leaks so I'm guessing a real one may be better. Amazing how much air comes out of a screw hole!!!!
Since the Bulldog's 3015 doesn't have as much use on it as the one in the PATH15, I'm letting it run at 20hz overnight and I'll retest tomorrow.
Considering the 99 db sensitivity of the 3015 I guess 3db above that is passable to replace my double 15 cabs. I was trying for 6db.
I'll post here again but I'll post the detailed stuff in a new thread
as this one is Loooooooooooonnnnnnnggggggg
Jbell sent me the 24x24x48 box, I whipped one up and also discovered it would fit in the 34x34x21 bulldog so I modded that one as well. The wonders of styrofoam modeling
They seemed to test about the same so I went with the 34x34x21 Bulldog vs the 40x28x21 PATH15 I was working on.
This way I was comparing two boxes I might actually use.
Listening to the two, the Bulldog sounded angrier and roared.
The Path15 sounded flatter. The bulldog seemed to want more power to achieve a good level. Testing revealed the PATH15 was actually the better box. It beat the Bulldog by about 3 db all around except at 60 and 50 where the Bulldog was 1 and two db hotter respectively. The ran neck and neck at 45 and 40 with the PATH15 4 db hotter at 38hz. Unlike the bulldog, the PATH is full of screw holes and air leaks so I'm guessing a real one may be better. Amazing how much air comes out of a screw hole!!!!
Since the Bulldog's 3015 doesn't have as much use on it as the one in the PATH15, I'm letting it run at 20hz overnight and I'll retest tomorrow.
Considering the 99 db sensitivity of the 3015 I guess 3db above that is passable to replace my double 15 cabs. I was trying for 6db.
I'll post here again but I'll post the detailed stuff in a new thread
as this one is Loooooooooooonnnnnnnggggggg
Thanks.
I did a research and found this nice page: http://en.wikipedia.org/wiki/Thiele/Small which explains everything.
One more question... If i add mass, does BL stay constant? (thats me trying to figure out what these equations mean)
I did a research and found this nice page: http://en.wikipedia.org/wiki/Thiele/Small which explains everything.
One more question... If i add mass, does BL stay constant? (thats me trying to figure out what these equations mean)
Sure you could, but to be on the safe side, try to change the horn parameters by small random amounts and see what happens to the notch. If its location and q is very much affected by little changes in parameters, you should rethink the design, because as the "horn in wood" is never a 1:1 representation of the model, you may have the notch somewhere where it hurts.
To be on the safe side, try to design the horn without a notch directly next to the used band. Additionally, i think one could make the graph more flat, but thats probably just cosmetics.
To be on the safe side, try to design the horn without a notch directly next to the used band. Additionally, i think one could make the graph more flat, but thats probably just cosmetics.
Ramps, reflectors, deflectors, whatever you call them...they work.
They smooth out the horn path for starters, second the help eliminate standing waves and cancellations inside the box.
With multiple folds you have multiple cancellations at multiple frequencies, compounded by adding the bends together for a new set of cancellations.
I deflectorized the two boxes I was working on and the difference is night and day. A touch more gain all around, severly minimised phase cancellations that were a big issue yesterday, and a generally "rounder" sound all around. The Deflectors brought the Bulldog out as a usable cabinet for PA use. In the PATH15 they also added a couple of db but the low end below 60 actually suffered. Probably because of the lost volume.
The Bulldog without deflectors was a muddy thumper, with a bad cancellation problem from 115 and up, and another at 70. With the deflectors it became a fairly clear toned with the phase issues minimised and starting at about 125-130. The key is to listen to aggressive bass guitar notes (not synths). The tests showed a couple of db better, but the ear test was what mattered.
The two cabinets are pretty close in measurements but the most interesting is the mouth angle and the relationship between the speaker. The Path15 has a steeper or higher angle and has much better mid bass tones, the Bulldog has a much shallower angle and seems to have better low bass tones.
I fired up both cabinets in parallel and fed them 500 (peak) watts at 4 ohms. NO EQ. Holy SH#$% Shook the whole building. 4 of these should wreck a small 5000 sq ft club quite easilly with only 1kw.
I used Edgar's concept on the deflectors. Basically the same size as the two horn sections you are joining. If the horn sections are 12x21 (opening), I used a 12x21 reflector, deflector, whatever.
The idea is to DEFLECT away as much as possible from reflecting back down the horn. In the case of a non 90 degree turn I used the same concept as in pool or billards to guess at the angle I needed.
They smooth out the horn path for starters, second the help eliminate standing waves and cancellations inside the box.
With multiple folds you have multiple cancellations at multiple frequencies, compounded by adding the bends together for a new set of cancellations.
I deflectorized the two boxes I was working on and the difference is night and day. A touch more gain all around, severly minimised phase cancellations that were a big issue yesterday, and a generally "rounder" sound all around. The Deflectors brought the Bulldog out as a usable cabinet for PA use. In the PATH15 they also added a couple of db but the low end below 60 actually suffered. Probably because of the lost volume.
The Bulldog without deflectors was a muddy thumper, with a bad cancellation problem from 115 and up, and another at 70. With the deflectors it became a fairly clear toned with the phase issues minimised and starting at about 125-130. The key is to listen to aggressive bass guitar notes (not synths). The tests showed a couple of db better, but the ear test was what mattered.
The two cabinets are pretty close in measurements but the most interesting is the mouth angle and the relationship between the speaker. The Path15 has a steeper or higher angle and has much better mid bass tones, the Bulldog has a much shallower angle and seems to have better low bass tones.
I fired up both cabinets in parallel and fed them 500 (peak) watts at 4 ohms. NO EQ. Holy SH#$% Shook the whole building. 4 of these should wreck a small 5000 sq ft club quite easilly with only 1kw.
I used Edgar's concept on the deflectors. Basically the same size as the two horn sections you are joining. If the horn sections are 12x21 (opening), I used a 12x21 reflector, deflector, whatever.
The idea is to DEFLECT away as much as possible from reflecting back down the horn. In the case of a non 90 degree turn I used the same concept as in pool or billards to guess at the angle I needed.
