Ok thanks guys again. I just did the comparison between the 2 plots (150 vs 120 liters) and as you said, the only difference is below 50 HZ. I will check regarding the dimensions to see if it is worth the small difference in size or if I will just stay with the 150 liter. The picture is below.
Another thing, I know that the Golden Ratio is the best possibility but I was measuring the size of the boxes that Loren just posted on the graphs and I remembered what I saw some time ago: They are HUGE!.
So I was fooling around with the dimensions while keeping the internal volume the same and saw that I can do them of: 620mm high by 560mm wide by 450mm deep.
Let me know if there is anything wrong with these dimensions besides not being Golden.
I was reading that even though the Golden Ratio is aimed mainly to suppress standing waves, they can also be dealt with angled or inclined cabinet walls, specially the front or rear ones. I can try to put that into the design, even though I know will make the construction a little harder.
Leo
Another thing, I know that the Golden Ratio is the best possibility but I was measuring the size of the boxes that Loren just posted on the graphs and I remembered what I saw some time ago: They are HUGE!.
So I was fooling around with the dimensions while keeping the internal volume the same and saw that I can do them of: 620mm high by 560mm wide by 450mm deep.Let me know if there is anything wrong with these dimensions besides not being Golden.
I was reading that even though the Golden Ratio is aimed mainly to suppress standing waves, they can also be dealt with angled or inclined cabinet walls, specially the front or rear ones. I can try to put that into the design, even though I know will make the construction a little harder.
Leo
Typically, the tweeter is on top. One reason is to get it at ear level. The other reason is to help with the vertical response.
I don't know how your proposed layout will impact the vertical profile of the response.
This is my 3-way.
An externally hosted image should be here but it was not working when we last tested it.
Only two sides are parallel (top and bottom). It has about 175 liters. The base is about 24" square at its widest and the very bottom is 21.45" square. It stands 33.5" tall and 20" wide and 20" deep at the top.
This design helps reduce internal resonances and the 3.8° front baffle angle helps place the tweeter's on-axis to point at the listener.
I should add that the top section with the mid and tweeter have their sides angled back in a bid to reduce diffraction.
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Ok cool I'll take that into consideration then. I was just trying to see if I could include the Tweeter inside the Woofer cabinet to reduce the combined height but unless I do it like yours (that by the way looks pretty cool ) , then I will have to do it separate with the tweeter on top.
Another question, is there a better practice as to where to place the ports? Top or bottom?
Leo
Another question, is there a better practice as to where to place the ports? Top or bottom?
Leo
The ports can go just about anywhere. Some purists feel the front baffle is the best, but I have seen ports on the sides, back, and bottom.
The only problem with locating ports on a different face than the baffle is room walls and neighboring objects may impact the ports.
As to where on the baffle to put them, I tend to put them closer to the bottom, but it isn't important.
Hi Leo,
Just a few quick notes...
First, boxes with 15" Woofers that run full-range are always huge...
Second, where with the tweeter - in our case and with the crossover we have in mind - at the top, a little above ear-hight.
Third, where do the ports go - I normally like to put them on the back. Plus, please make sure you have plenty of surface area. Loads of surface area for the ports reduces compression and windnoise, rear mounting means anything from the port that we do not want to hear, but that comes through anyway points away from the listener.
You need to look however that the distance between driver and port does not become more than 1/4 of the wavelength at the tuning frequency.
Fourth, the golden ratio is not an absolute rule, it just tends to give visually appealing systems and somehow seems to do better at avoiding the reinforcement of standing waves.
As for non-parallel walls, they would have to be VERY non-parallel to do anything at the frequencies of the standing waves. Basically the whole non-parallel walls reduce standing waves balooney spouted by many players in this industry is not worth the paper it is printed on.
Ciao T
Just a few quick notes...
First, boxes with 15" Woofers that run full-range are always huge...
Second, where with the tweeter - in our case and with the crossover we have in mind - at the top, a little above ear-hight.
Third, where do the ports go - I normally like to put them on the back. Plus, please make sure you have plenty of surface area. Loads of surface area for the ports reduces compression and windnoise, rear mounting means anything from the port that we do not want to hear, but that comes through anyway points away from the listener.
You need to look however that the distance between driver and port does not become more than 1/4 of the wavelength at the tuning frequency.
Fourth, the golden ratio is not an absolute rule, it just tends to give visually appealing systems and somehow seems to do better at avoiding the reinforcement of standing waves.
As for non-parallel walls, they would have to be VERY non-parallel to do anything at the frequencies of the standing waves. Basically the whole non-parallel walls reduce standing waves balooney spouted by many players in this industry is not worth the paper it is printed on.
Ciao T
Ok then another question, how do you measure the distance between the driver and ports?
Is it just straight distance in the baffle? How do you measure it if you put the ports in the back wall?
As for the non-parallel walls, I was thinking about making them very non-parallel as you say. I'll work a design and show it to you guys and see what you think about the possible technical problems.
Thanks.
Leo
Is it just straight distance in the baffle? How do you measure it if you put the ports in the back wall?
As for the non-parallel walls, I was thinking about making them very non-parallel as you say. I'll work a design and show it to you guys and see what you think about the possible technical problems.
Thanks.
Leo
If you tune the ports to 38 Hz, then one wavelength is 9 meters long. 1/4 of that is 2.27 meters (89.4"). If you were to measure from the center of the port on the baffle face to the center of the woofer on the baffle face using a string, that string must be less than 89.4" long.
Don't get too hung up with non-parallel walls. Doing that mandates a lot of compound angle cuts in the wood and it leaves little room for error when you make those cuts. The benefit of non-parallel walls is not worth a lot of effort to do.
You can achieve good results with using good internal damping materials, solid wall bracing, and sound deadening materials on the inside walls to reduce cabinet wall vibrations. Roofing felt stapled to the cabinet walls is supposed to do a good job. Then put the damping material over that.
Another approach is to use constrained layering. Essentially, you are building a box within a box separated with a dampening material such as Green Glue. Again, the amount of effort expended to do constrained layering only buys you a little better damping, so there are diminished returns for the effort.
One thing that will help with the box is rounding over the baffle edges with a 2" radius or a 2" 45° bevel on the baffle edge to reduce diffraction. I found this link to a supplier that sells large radius MDF corners to make this job easy.
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Yes I know that making the non parallel walls will add a lot of complexity to the job but I am not thinking about it only for the benefits but also it would add a lot to the looks and I want to design something I can keep for many, many years and be happy with.
I am still not sure about going that route but I will keep thinking.
Thanks for the link, that will help certainly with the rounded corners.
Ok, so the distance then is more than enough to make almost any kind of combination between the driver and the ports because 2.2 meters is a lot, I should not have any problems with that.
Will keep playing with the designs
Thanks.
Leo
I am still not sure about going that route but I will keep thinking.
Thanks for the link, that will help certainly with the rounded corners.
Ok, so the distance then is more than enough to make almost any kind of combination between the driver and the ports because 2.2 meters is a lot, I should not have any problems with that.
Will keep playing with the designs
Thanks.
Leo
Hi,
Again, this is of the same variety of non-parallel walls. A 2" radius is equal to a wavelength of around 7KHz.
In our case we have drivers that are quite directional at 7KHz (the audax is 10dB down against on axis at 30 Degrees already) and indeed much lower by the time we are at 90 degrees. In order to diffract of the edges the sound needs to get to the edges if it does not get there no point expending effort.
So there is some sense for rounding over edges with speakers that use wide dispersion dome tweeters, but very little with the kind of speaker we are discussing.
Of course, radiused edges look really nice and so it is probably still worth including them, but don't loose too much sleep over them if it is difficult or expensive.
If you want to fight diffraction in the type of speaker we are working on here, you need to look at "stealth fighter" chevrons and things like that with significant size, similar to what Loren did on his speakers.
Ciao T
Again, this is of the same variety of non-parallel walls. A 2" radius is equal to a wavelength of around 7KHz.
In our case we have drivers that are quite directional at 7KHz (the audax is 10dB down against on axis at 30 Degrees already) and indeed much lower by the time we are at 90 degrees. In order to diffract of the edges the sound needs to get to the edges if it does not get there no point expending effort.
So there is some sense for rounding over edges with speakers that use wide dispersion dome tweeters, but very little with the kind of speaker we are discussing.
Of course, radiused edges look really nice and so it is probably still worth including them, but don't loose too much sleep over them if it is difficult or expensive.
If you want to fight diffraction in the type of speaker we are working on here, you need to look at "stealth fighter" chevrons and things like that with significant size, similar to what Loren did on his speakers.
Ciao T
Hi Leo,
Yup. And after the discussions above you know you can put the ports almost anywhere, though closer to the floor is still better and you know you can use non-parallel walls and rounded corners, but you do not have to. The bottom line you do not need to concern yourself much at all with the whole shebang on the acoustic side, you can just make any shape you like, just make the box big enough.
It is worth noting that we want to use the 15" woofer up to around 500Hz. This means you need to watch standing waves.
One way to break up standing waves and to reinforce the speaker at the time is to use multiple internal chambers linked together with ports tuned high enough that they do not interfere with the low bass frequencies but which progressively reduce the box size as the frequency goes up.
The way this works is that each port is a lowpass. Frequencies below the ports resonance pass, frequencies above are progressively attenuated.
So let's say you have a box that 120cm tall. You have a major standing wave at 290Hz, well within our target frequency range.
Now say you subdivide the box into two chambers and you tune the port between the chambers to around 80Hz. Now, at 40Hz this port does not do anything, if it's cross-section is sufficiently large. At 80Hz this port will put a little notch into your reponse, but very little. Above 80Hz the port iwll appear essentially "closed" to the soundwaves, which hence no longer enter the second chamber.
And the main standing wave is now banished up in frequency to nearly 600Hz or even more, if we used an asymetric distribution of the two volumes/length (say according to the golden ratio?) and placed our driver into the smaller chamber.
The alternative would be to use the vertical resonance constructively and turn the whole thing into a "Mass Loaded Transmission Line".
Another thing.
If you build your port as a slot port and you do it similar to the design in the EV TL-606 you can set things so you can change the tuning of the speaker simply by "baffeling off" sections of the port. If the port is on the back at the base of the speaker this would be easy to do and not much of an eyesore.
http://archives.telex.com/archives/EV/Builders%20Plans/TL606%20Builders%20Plans.pdf
With a port subdivided three ways you can have three distinct possible tunings. One might have one tuning that is distinctly for use with bass management and free-standing placement and one deisgned for close to wall placement and a third that will always require equalisation but would allow the lowest Bass cutoff.
Ciao T
Yup. And after the discussions above you know you can put the ports almost anywhere, though closer to the floor is still better and you know you can use non-parallel walls and rounded corners, but you do not have to. The bottom line you do not need to concern yourself much at all with the whole shebang on the acoustic side, you can just make any shape you like, just make the box big enough.
It is worth noting that we want to use the 15" woofer up to around 500Hz. This means you need to watch standing waves.
One way to break up standing waves and to reinforce the speaker at the time is to use multiple internal chambers linked together with ports tuned high enough that they do not interfere with the low bass frequencies but which progressively reduce the box size as the frequency goes up.
The way this works is that each port is a lowpass. Frequencies below the ports resonance pass, frequencies above are progressively attenuated.
So let's say you have a box that 120cm tall. You have a major standing wave at 290Hz, well within our target frequency range.
Now say you subdivide the box into two chambers and you tune the port between the chambers to around 80Hz. Now, at 40Hz this port does not do anything, if it's cross-section is sufficiently large. At 80Hz this port will put a little notch into your reponse, but very little. Above 80Hz the port iwll appear essentially "closed" to the soundwaves, which hence no longer enter the second chamber.
And the main standing wave is now banished up in frequency to nearly 600Hz or even more, if we used an asymetric distribution of the two volumes/length (say according to the golden ratio?) and placed our driver into the smaller chamber.
The alternative would be to use the vertical resonance constructively and turn the whole thing into a "Mass Loaded Transmission Line".
Another thing.
If you build your port as a slot port and you do it similar to the design in the EV TL-606 you can set things so you can change the tuning of the speaker simply by "baffeling off" sections of the port. If the port is on the back at the base of the speaker this would be easy to do and not much of an eyesore.
http://archives.telex.com/archives/EV/Builders%20Plans/TL606%20Builders%20Plans.pdf
With a port subdivided three ways you can have three distinct possible tunings. One might have one tuning that is distinctly for use with bass management and free-standing placement and one deisgned for close to wall placement and a third that will always require equalisation but would allow the lowest Bass cutoff.
Ciao T
Ok thanks Thorsten, good ideas. I will think about the slot port and see if I can incorporate it into the design.
Another thing, after almost a month since I sent the questions to the Peavey customer support they finally answered. They say that the Xmech of this driver is huge, around 10 to 12 mm so that I should not be concerned much about hitting it.
Also he said this that may be of use: "One more thing I forgot to mention, the Xmech, or point of excursion where the woofer would be damaged is MUCH higher than the Xmax (which is a measure of linearity), on this woofer about 10-12 mm before damage. Also, these numbers are +/-, not both ways, so they may look 1/2 as good as many of the competition's numbers. Xmax is supposed to be +/-, but many folks quote the number for both ways, so by their measure, the 1502 would have 5.2 mm Xmax. Just an FYI"
Leo
Another thing, after almost a month since I sent the questions to the Peavey customer support
they finally answered. They say that the Xmech of this driver is huge, around 10 to 12 mm so that I should not be concerned much about hitting it.Also he said this that may be of use: "One more thing I forgot to mention, the Xmech, or point of excursion where the woofer would be damaged is MUCH higher than the Xmax (which is a measure of linearity), on this woofer about 10-12 mm before damage. Also, these numbers are +/-, not both ways, so they may look 1/2 as good as many of the competition's numbers. Xmax is supposed to be +/-, but many folks quote the number for both ways, so by their measure, the 1502 would have 5.2 mm Xmax. Just an FYI"
Leo
Another interesting thing he pointed out: He sent links for possible midrange and tweeters that could work with this Peavey and the first midrange was the Audax PR170N0 :
Other possible Midranges: Eminence Alpha 6A speaker. The Eminence Alpha 6A is a 6" 8 ohm speaker. Alpha-6A is a 100 watt RMS 6" speaker. ( not enough dB? )
Faital Pro 10FH500 10" Speakers - Faital Pro 10FH500 mid-bass, bass guitar speaker and subwoofer 10" speaker that has a lightweight neodymium magnet - Faital Pro 10FH500 1,200 watt 10" efficiency of 96dB SPL woofer for all high power bass application
B&C 6 PEV13 is a 6.5" midrange speaker - B&C Speakers - B&C 6.5" midrange speaker for 3 or 4-way sytems. B&C 6 PEV13 midrange speakers available now.
Tweeters: Faital Pro HF100 - Faital Pro HF100 1" neodymium high frequency compression driver. Faital Pro HF100 HF drivers available here at US Speaker.
Beyma CP22 - Beyma CP22 1" high frequency bullet tweeter delivers a quality highs for speakers and bass guitar tweeters upgrade. Beyma CP22 speaker components available at US Speaker. ( too expensive)
RCF Speakers - RCF ND1411-M - RCF ND1411-M 1" high frequency compression driver. RCF ND1411M 1" high frequency compression driver handles 50 watts program. RCF speaker components.
Ciare 1.26NdTW tweeter- Ciare 1.26NdTW is a lightweight neodymium tweeter for all high quality high frequency speaker systems - Ciare Speakers - Ciare 1.26NdTW tweeters available now.
Beyma T2030 - Beyma T2030 metal dome tweeter. Beyma speaker components available at US Speaker.
Just so you knew what were the options he posted.
Leo
:Other possible Midranges: Eminence Alpha 6A speaker. The Eminence Alpha 6A is a 6" 8 ohm speaker. Alpha-6A is a 100 watt RMS 6" speaker. ( not enough dB? )
Faital Pro 10FH500 10" Speakers - Faital Pro 10FH500 mid-bass, bass guitar speaker and subwoofer 10" speaker that has a lightweight neodymium magnet - Faital Pro 10FH500 1,200 watt 10" efficiency of 96dB SPL woofer for all high power bass application
B&C 6 PEV13 is a 6.5" midrange speaker - B&C Speakers - B&C 6.5" midrange speaker for 3 or 4-way sytems. B&C 6 PEV13 midrange speakers available now.
Tweeters: Faital Pro HF100 - Faital Pro HF100 1" neodymium high frequency compression driver. Faital Pro HF100 HF drivers available here at US Speaker.
Beyma CP22 - Beyma CP22 1" high frequency bullet tweeter delivers a quality highs for speakers and bass guitar tweeters upgrade. Beyma CP22 speaker components available at US Speaker. ( too expensive)
RCF Speakers - RCF ND1411-M - RCF ND1411-M 1" high frequency compression driver. RCF ND1411M 1" high frequency compression driver handles 50 watts program. RCF speaker components.
Ciare 1.26NdTW tweeter- Ciare 1.26NdTW is a lightweight neodymium tweeter for all high quality high frequency speaker systems - Ciare Speakers - Ciare 1.26NdTW tweeters available now.
Beyma T2030 - Beyma T2030 metal dome tweeter. Beyma speaker components available at US Speaker.
Just so you knew what were the options he posted.
Leo
Another interesting thing he pointed out: He sent links for possible midrange and tweeters that could work with this Peavey and the first midrange was the Audax PR170N0
Other possible Midranges: Eminence Alpha 6A speaker. The Eminence Alpha 6A is a 6" 8 ohm speaker. Alpha-6A is a 100 watt RMS 6" speaker. ( not enough dB? )
Faital Pro 10FH500 10" Speakers - Faital Pro 10FH500 mid-bass, bass guitar speaker and subwoofer 10" speaker that has a lightweight neodymium magnet - Faital Pro 10FH500 1,200 watt 10" efficiency of 96dB SPL woofer for all high power bass application
B&C 6 PEV13 is a 6.5" midrange speaker - B&C Speakers - B&C 6.5" midrange speaker for 3 or 4-way sytems. B&C 6 PEV13 midrange speakers available now.
Tweeters: Faital Pro HF100 - Faital Pro HF100 1" neodymium high frequency compression driver. Faital Pro HF100 HF drivers available here at US Speaker.
Beyma CP22 - Beyma CP22 1" high frequency bullet tweeter delivers a quality highs for speakers and bass guitar tweeters upgrade. Beyma CP22 speaker components available at US Speaker. ( too expensive)
RCF Speakers - RCF ND1411-M - RCF ND1411-M 1" high frequency compression driver. RCF ND1411M 1" high frequency compression driver handles 50 watts program. RCF speaker components.
Ciare 1.26NdTW tweeter- Ciare 1.26NdTW is a lightweight neodymium tweeter for all high quality high frequency speaker systems - Ciare Speakers - Ciare 1.26NdTW tweeters available now.
Beyma T2030 - Beyma T2030 metal dome tweeter. Beyma speaker components available at US Speaker.
Just so you knew what were the options he posted.
Leo
I have the Eminence and they are not as good as the Audax.
Yes I am sure that since you 2 pointed out the Audax and the guy from Peavey also did the same as first option, it has to be the best choice for me.
But here goes another question, I know that I am kinda constrained to drivers that have a sensitivity very close to 98 or 99 dB to match the Peavey, thats why the choice of the Fostex tweeter that was recommended by you guys. But what if I install a couple of tweeters instead of just one? I read that if you place 2 equal drivers, the output raises around 3 dB?
So in that case, would it be ok to place for example 2 of the Fountek NeoCd3.5H Horn Tweeters? ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=8818 ) They have a sensitivity of 95.5 dB plus the 3dB would be close. The only problem would be the impedance.
If I use a couple of Hi-Vi RT1C-A ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=1486 ), they have 94 dB sensitivity but they also are 5 ohms so they could be connected in parallel right?
I am just looking around and learning so dont get mad with me
Leo
But here goes another question, I know that I am kinda constrained to drivers that have a sensitivity very close to 98 or 99 dB to match the Peavey, thats why the choice of the Fostex tweeter that was recommended by you guys. But what if I install a couple of tweeters instead of just one? I read that if you place 2 equal drivers, the output raises around 3 dB?
So in that case, would it be ok to place for example 2 of the Fountek NeoCd3.5H Horn Tweeters? ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=8818 ) They have a sensitivity of 95.5 dB plus the 3dB would be close. The only problem would be the impedance.
If I use a couple of Hi-Vi RT1C-A ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=1486 ), they have 94 dB sensitivity but they also are 5 ohms so they could be connected in parallel right?
I am just looking around and learning so dont get mad with me
Leo
Yes I am sure that since you 2 pointed out the Audax and the guy from Peavey also did the same as first option, it has to be the best choice for me.
But here goes another question, I know that I am kinda constrained to drivers that have a sensitivity very close to 98 or 99 dB to match the Peavey, thats why the choice of the Fostex tweeter that was recommended by you guys. But what if I install a couple of tweeters instead of just one? I read that if you place 2 equal drivers, the output raises around 3 dB?
So in that case, would it be ok to place for example 2 of the Fountek NeoCd3.5H Horn Tweeters? ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=8818 ) They have a sensitivity of 95.5 dB plus the 3dB would be close. The only problem would be the impedance.
If I use a couple of Hi-Vi RT1C-A ( https://www.madisound.com/store/product_info.php?cPath=45_229_236&products_id=1486 ), they have 94 dB sensitivity but they also are 5 ohms so they could be connected in parallel right?
I am just looking around and learning so dont get mad with me
Leo
Compounding drivers does work, but you also halve the impedance. You also have the issue of lobbing because the drivers interfere with each other's patterns. That means that alignment and position of the drivers is more critical.
What you are proposing is doable, but makes the design more complicated.
Hi,
Yes, completely agreed on the Xmax issue. Unless driven very hard in a PA setup it is pretty hard to physically PA Woofers.
Not enough dB AND poor quality.
I don't know this one, but a 10" Driver is probably too big in terms required cabinet volume etc.
This is quite similar to the Audax, in our circles the Audax is generally better known. If you had problems getting the Audax it would be a good second choice.
The Faital Pro Driver is just a driver, you need to add a horn. Also the frequency response ia bit iffy, for our own specific use.
Yes, this a very good (and possibly better) alternative to the Fostex units I am suggestung. I like thia and the Beyma Slot radiator (CP21F) (and their close equivalents from JBL and Fane) very much and have used them many times since the 80's, both for PA service and in home/studio speakers.
This again needs a Horn added, not really what we are looking for.
This is a good alternative to the Fostex, but I would think the Fostex would still be my choice.
This one does not have enough SPL and has not so good dispersion control. It has uses but is not right for us.
Not just that, you also set a quite low ceiling for driver cost.
To give you some reasoning for the Fostex from me.
Used as I suggest (as supertweeter or as "fill-in" tweeter above the natural cutoff of the Audax) it works very well and sounds good (I have used it a few times before). It is also quite inexpensive.
It is also used in several HiFi speakers, including a number of units from BC Speakers and the small Kiso/Takamine monitors, which received "best sound of the show" from several corners at the most recent Munich HiFi show when driven by the cheaper line of the AMR Electronics (modesty obliges me to point out that I am the lead designer for all AMR stuff).
It also has a dispersion pattern (that is how the off axis response changes compared to on axis) that dovetails nicely with the dispersion of cone drivers higher up.
That is generally "a bad idea" (there are specific cases where it can be a "good idea", but these are very specific cases).
Kind of. The SPL for 1W/1m rises 3dB.
If you wire the drivers in series you get double the impedance and same 2.83V/1m SPL, so halve the power for the same SPL or a 3dB increase in efficiency, but NO increase in actual SPL.
If you wire the drives in parallel, you get halve the impedance and 6dB more 2.83V/1m SPL, so double the for 6dB more SPL increase (actual SPL) and a 3dB increase in efficiency.
However this only holds true as long as the drivers acoustic centers are closer together than around 1/4 of the Wavelength being radiated. The wavelength at 20KHz is around 1.8cm, so the centers of your drivers need to be less 5mm in distance.
Otherwise the delay between the drivers produces destructive interference leading to what is called lobing, meaning at some angles there is very little output, at others there is full output and overall net SPL is also reduced as a result.
Not just impedance, you cannot really stack these. So you would have to go about things a different way.
I know these quite well, if you want to "stack" them you would need the OEM version without faceplate and you would need to machine your own faceplate.
Also, the 94dB are more than optimistic, at 15KHz the usable SPL is around 91dB and you need to equalise the frequency response. With their 5 Ohm impedance they would give you 97dB/2.83V with a 2.5 Ohm impedance for a pair, or for an array of four you would get 97dB/2.83V/1m with a 5 Ohm impedance. Not suitable IMHO and much headache.
To be honest, the tweeters are intended (in my suggestion anyway) to only cover very high frequencies. This means you get much less benefits from any of Ribbon/Magnetostat tweeters.
The big issue with any of these is that they have a very different dispersion pattern than the main driver and are much harder to integrate.
If you must use them consider the Fountek NeoCD2.0 (97dB, but 100dB in the range where we need it) or the Hi-Vi RT2-Pro (my choice would be the RT2-Pro between the two BTW) instead.
If you are that keen on Ribbons, how about you save a bit more and buy the HF Units from the diyhifisupply Crescendo speaker Kit?
They will work with a simple low order crossover at well below 1KHz and would give a 2-Way with your Peavey woofers that would be quite outstanding...
Ciao T
Yes, completely agreed on the Xmax issue. Unless driven very hard in a PA setup it is pretty hard to physically PA Woofers.
Not enough dB AND poor quality.
I don't know this one, but a 10" Driver is probably too big in terms required cabinet volume etc.
This is quite similar to the Audax, in our circles the Audax is generally better known. If you had problems getting the Audax it would be a good second choice.
The Faital Pro Driver is just a driver, you need to add a horn. Also the frequency response ia bit iffy, for our own specific use.
Yes, this a very good (and possibly better) alternative to the Fostex units I am suggestung. I like thia and the Beyma Slot radiator (CP21F) (and their close equivalents from JBL and Fane) very much and have used them many times since the 80's, both for PA service and in home/studio speakers.
This again needs a Horn added, not really what we are looking for.
This is a good alternative to the Fostex, but I would think the Fostex would still be my choice.
This one does not have enough SPL and has not so good dispersion control. It has uses but is not right for us.
Not just that, you also set a quite low ceiling for driver cost.
To give you some reasoning for the Fostex from me.
Used as I suggest (as supertweeter or as "fill-in" tweeter above the natural cutoff of the Audax) it works very well and sounds good (I have used it a few times before). It is also quite inexpensive.
It is also used in several HiFi speakers, including a number of units from BC Speakers and the small Kiso/Takamine monitors, which received "best sound of the show" from several corners at the most recent Munich HiFi show when driven by the cheaper line of the AMR Electronics (modesty obliges me to point out that I am the lead designer for all AMR stuff).
It also has a dispersion pattern (that is how the off axis response changes compared to on axis) that dovetails nicely with the dispersion of cone drivers higher up.
That is generally "a bad idea" (there are specific cases where it can be a "good idea", but these are very specific cases).
Kind of. The SPL for 1W/1m rises 3dB.
If you wire the drivers in series you get double the impedance and same 2.83V/1m SPL, so halve the power for the same SPL or a 3dB increase in efficiency, but NO increase in actual SPL.
If you wire the drives in parallel, you get halve the impedance and 6dB more 2.83V/1m SPL, so double the for 6dB more SPL increase (actual SPL) and a 3dB increase in efficiency.
However this only holds true as long as the drivers acoustic centers are closer together than around 1/4 of the Wavelength being radiated. The wavelength at 20KHz is around 1.8cm, so the centers of your drivers need to be less 5mm in distance.
Otherwise the delay between the drivers produces destructive interference leading to what is called lobing, meaning at some angles there is very little output, at others there is full output and overall net SPL is also reduced as a result.
Not just impedance, you cannot really stack these. So you would have to go about things a different way.
I know these quite well, if you want to "stack" them you would need the OEM version without faceplate and you would need to machine your own faceplate.
Also, the 94dB are more than optimistic, at 15KHz the usable SPL is around 91dB and you need to equalise the frequency response. With their 5 Ohm impedance they would give you 97dB/2.83V with a 2.5 Ohm impedance for a pair, or for an array of four you would get 97dB/2.83V/1m with a 5 Ohm impedance. Not suitable IMHO and much headache.
To be honest, the tweeters are intended (in my suggestion anyway) to only cover very high frequencies. This means you get much less benefits from any of Ribbon/Magnetostat tweeters.
The big issue with any of these is that they have a very different dispersion pattern than the main driver and are much harder to integrate.
If you must use them consider the Fountek NeoCD2.0 (97dB, but 100dB in the range where we need it) or the Hi-Vi RT2-Pro (my choice would be the RT2-Pro between the two BTW) instead.
If you are that keen on Ribbons, how about you save a bit more and buy the HF Units from the diyhifisupply Crescendo speaker Kit?
They will work with a simple low order crossover at well below 1KHz and would give a 2-Way with your Peavey woofers that would be quite outstanding...
Ciao T
Hi thorsten and Loren, thanks for your thoughts. I see now why using 2 tweeters is not such a good idea . So scrap that thought.
Now the possibility of using the NeoCD2.0 or the Hi Vi RT2-PRO is still in my mind. It is simply that I LOVE the look of the ribbon drivers and for that matter the NEO more than the Hi Vi. I will see if I can save the money for them and let you know.
As for the Ribbon from the Crescendo, it looks amazing but I couldnt find any price for it alone. But by seeing the price of the speaker system, I think it will be way out of my budget. Thorsten if you know, let me know the price of them please.
Now, let say I go with the Crescendo Ribbon ( I can wish right?) and do a 2 way, do you think it will be as good as the 3 way?
Thanks...
Leo
. So scrap that thought.Now the possibility of using the NeoCD2.0 or the Hi Vi RT2-PRO is still in my mind. It is simply that I LOVE the look of the ribbon drivers and for that matter the NEO more than the Hi Vi. I will see if I can save the money for them and let you know.
As for the Ribbon from the Crescendo, it looks amazing but I couldnt find any price for it alone. But by seeing the price of the speaker system, I think it will be way out of my budget
. Thorsten if you know, let me know the price of them please.Now, let say I go with the Crescendo Ribbon ( I can wish right?) and do a 2 way, do you think it will be as good as the 3 way?
Thanks...
Leo
Hi,
There is no separate price, but there is a price for the Driver Pack only, the 8" Drivers are around 1/2 the price of the Ribbon/Horns...
NO WAY.
It will be MUCH better. The Ribbon running for most of upper midrange and the rest is completely amazing. There is very little I have heard at any price that comes even close. Closest are really large electrostatic speakers and such exotic stuff...
Ciao T
As for the Ribbon from the Crescendo, it looks amazing but I couldnt find any price for it alone. But by seeing the price of the speaker system, I think it will be way out of my budget
There is no separate price, but there is a price for the Driver Pack only, the 8" Drivers are around 1/2 the price of the Ribbon/Horns...
NO WAY.
It will be MUCH better. The Ribbon running for most of upper midrange and the rest is completely amazing. There is very little I have heard at any price that comes even close. Closest are really large electrostatic speakers and such exotic stuff...
Ciao T
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