I actually have a 20-20k 2-way. It consists of the B&G RD-75 ribbon covering 200 - 20kHz, and four 21" Beyma woofers from 20 - 200 Hz.
Thank you all.
I should have been more specific about the application.
I am a musician/sound "engineer", and these days I am enjoying building studios for friends. I would like to integrate monitor design along with the control room design... the speakers will be decoupled and flush mounted with the wall. There is no system for this application at under $20K.
In my next build, I will almost definitely go with digital loudspeaker management, primarily to have flexibility with regard to crossover points and slopes, and to be able to roll off the bass, as appropriate for half space loading in the room.
I would like to keep it 2-way to reduce complications, expense and necessary amplification. The design has to be simple, because we are no experts here.
Just to be clear... the econowaves I have built are not lacking in bass at all. They do 20 Hz easily and 30 Hz with authority. But the two drivers sound different from each other, and one of them has some mechanical resonance issues... Poor QC is my guess. One of the things I'm looking for is a higher end equivalent of the DC300 (preferably with a more robust magnet).
I find it strange that many here are suggesting that 20-20 is a near impossible task for a two way... I do understand that speaker building is a very imperfect science and you never have an uncompromised design...
Here is another example of a two way that does 20-20.
I should have been more specific about the application.
I am a musician/sound "engineer", and these days I am enjoying building studios for friends. I would like to integrate monitor design along with the control room design... the speakers will be decoupled and flush mounted with the wall. There is no system for this application at under $20K.
In my next build, I will almost definitely go with digital loudspeaker management, primarily to have flexibility with regard to crossover points and slopes, and to be able to roll off the bass, as appropriate for half space loading in the room.
I would like to keep it 2-way to reduce complications, expense and necessary amplification. The design has to be simple, because we are no experts here.
Just to be clear... the econowaves I have built are not lacking in bass at all. They do 20 Hz easily and 30 Hz with authority. But the two drivers sound different from each other, and one of them has some mechanical resonance issues... Poor QC is my guess. One of the things I'm looking for is a higher end equivalent of the DC300 (preferably with a more robust magnet).
I find it strange that many here are suggesting that 20-20 is a near impossible task for a two way... I do understand that speaker building is a very imperfect science and you never have an uncompromised design...
Here is another example of a two way that does 20-20.
What is the price of JBL 223 and TAD TD2001 at the market?
Anyway, some time ago these Overview were about 250 Euro, I don't know for today. They are able to go as low as 300 hz according to the specs.
This makes a three way, but a 7 to 20 khz tweeter works for only an octave and a half or so, so you will close your eyes for that third way 🙂
A behringer DCX would enable you to tailor the response curve as well as the crossover curves and you will be able to mix digital sources directly played through it's DAC.
With the midrange brought doun to ~300 hz you now have a greater choice of woofers.
It seems that you could do it with ~1400 $ budget.
Anyway, some time ago these Overview were about 250 Euro, I don't know for today. They are able to go as low as 300 hz according to the specs.
This makes a three way, but a 7 to 20 khz tweeter works for only an octave and a half or so, so you will close your eyes for that third way 🙂
A behringer DCX would enable you to tailor the response curve as well as the crossover curves and you will be able to mix digital sources directly played through it's DAC.
With the midrange brought doun to ~300 hz you now have a greater choice of woofers.
It seems that you could do it with ~1400 $ budget.
I saw youre thinking of the SB Acoustic drivers. If youve read Zaph (Zaph|Audio) opinions on the 12inch driver youll be conwinced its a good driver. Very high quality motor system. And as you say a good LF extension. But for your needs maybe the 15 inch would be better. How low can you do the crossover?
The only problem is that for a placement close to the walls you cant do a box that has full lvl all the way down. A average room reinforcement curve is something like 10dB boost at 20 hz and starts at a gentle rise from around 60Hz. If one can get the driver very close to the wall you can get reinforcement all the way from 300Hz. But in your case the box size wont allow that, unless you make the box very thin and tall.
But that 15 inch SB would be able to do something like 113 dB/1m before the excursion is spent. With the reinforcement of the room youd get about the same spl at listening position. All according to the simulation of course. Only problem would be the 250W(into 8ohm or 44.5V) youd have to put in. So it might not be practical. Even so I dont think youll be playing those lvls for any extended periods. For a more sensible 100dB you only need 5W (8ohm, 6.3V) with quite some headroom (especially when you factor in the other speaker). The 12inch SB actually have bette LF-extension but youd need more power and more excursion for the same lvl of course.
(Those simulations give a volume of 213 and 180l respectivley both with 19-20hz tuning)
But you might want to consider a PA woofer instead. Like the JBL or perhaps B&C since they have similar performance for less cost. Depending on how you feel you might want a bit of different T/S values for your application. Again it would depend on the spl you need. More power to the driver will give more power compression.
If the box have a "maximum flat" curve youll get a boost in the LF, so in the room curve wont be "flat". However the phsycoacoustical flat curve actually call for a boost inte the LF so it might work.
Heres a picture of how that average room boost cruve might look like. Its the green curve in the first picture. That picture also shows how a 5inch woofer coupled to the wall might get boosted. And also give you a sense of what the free air curve might look like for a "flat" in-room curve. Top right you have the group delay curve for what is audible for humans (blue curve). Keep under that and youll be ok. It isnt entirely true since we are more sensitive to GD in the 200Hz range (one reason for not doing crossover between 100-300Hz)
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=11362&list=full
Zaphs speaker with SB12 can be found here: Zaph|Audio - SB12.3 3-Way Tower
The only problem is that for a placement close to the walls you cant do a box that has full lvl all the way down. A average room reinforcement curve is something like 10dB boost at 20 hz and starts at a gentle rise from around 60Hz. If one can get the driver very close to the wall you can get reinforcement all the way from 300Hz. But in your case the box size wont allow that, unless you make the box very thin and tall.
But that 15 inch SB would be able to do something like 113 dB/1m before the excursion is spent. With the reinforcement of the room youd get about the same spl at listening position. All according to the simulation of course. Only problem would be the 250W(into 8ohm or 44.5V) youd have to put in. So it might not be practical. Even so I dont think youll be playing those lvls for any extended periods. For a more sensible 100dB you only need 5W (8ohm, 6.3V) with quite some headroom (especially when you factor in the other speaker). The 12inch SB actually have bette LF-extension but youd need more power and more excursion for the same lvl of course.
(Those simulations give a volume of 213 and 180l respectivley both with 19-20hz tuning)
But you might want to consider a PA woofer instead. Like the JBL or perhaps B&C since they have similar performance for less cost. Depending on how you feel you might want a bit of different T/S values for your application. Again it would depend on the spl you need. More power to the driver will give more power compression.
If the box have a "maximum flat" curve youll get a boost in the LF, so in the room curve wont be "flat". However the phsycoacoustical flat curve actually call for a boost inte the LF so it might work.
Heres a picture of how that average room boost cruve might look like. Its the green curve in the first picture. That picture also shows how a 5inch woofer coupled to the wall might get boosted. And also give you a sense of what the free air curve might look like for a "flat" in-room curve. Top right you have the group delay curve for what is audible for humans (blue curve). Keep under that and youll be ok. It isnt entirely true since we are more sensitive to GD in the 200Hz range (one reason for not doing crossover between 100-300Hz)
An externally hosted image should be here but it was not working when we last tested it.
http://www.faktiskt.se/modules.php?name=Forums&file=viewtopic&t=11362&list=full
Zaphs speaker with SB12 can be found here: Zaph|Audio - SB12.3 3-Way Tower
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The speakers would be loaded in-wall, also called half-space loading leading to a 6 dB boost in the low frequencies.
Yes, but Zaph is crossing it over pretty low. I wonder if it can perform to above 1 KHz.
I am considering my options... like a DE250 crossed over @ 1 KHz to a 15" driver... I'm also looking at the Manger full range unit, crossed over at 830 Hz or so... But these are bastardizations of designs I have seen elsewhere... just looking for more sources of inspiration...
That's pretty cool, I didnt know the RD-75 ribbon played that low. 4 21" beyma woofers would be fun too 😀 Do you have pics or a build link?
Take a look at that: http://bmsspeakers.com/fileadmin/bms-data/curves_compression/ferrite/bms_4590_curves.jpg - even nicer response
The same coaxial compression driver, but with ferrite magnet Overview
Even a 15 in driver will have IM distortion when required to do big excursions and go up to 1 khz.
Wow - 9 kg http://bmsspeakers.com/fileadmin/bms-data/product_data/compression_drivers/ferrite/bms_4590_4590p_t.data.pdf
And you can get that one with it's original crossover. Image
The same coaxial compression driver, but with ferrite magnet Overview
Even a 15 in driver will have IM distortion when required to do big excursions and go up to 1 khz.
Wow - 9 kg http://bmsspeakers.com/fileadmin/bms-data/product_data/compression_drivers/ferrite/bms_4590_4590p_t.data.pdf
And you can get that one with it's original crossover. Image
My 2-way 20Hz to 20Khz build this summer is the IWATA-300 horn/18sound 2" CD + AV15X woofer. I would use the TAD CDs but they are just too expensive.
The 18sound CD does measure up to 20KHz but obviously Im losing directivity much lower, I still want to hear it. If it does not work I will switch to the BMS 4590p (coax CD just mentioned above).
The AV15X woofers are incredible subwoofers with extremely low Le values. The measure well even up to 500Hz.
If you need a 15" woofer that runs up to 1KHz then I would recommend the TD15M driver from www.aespeakers.com. Its measurements up to 1Khz are unmatched but you do loose performance really low, no way it runs to 20Hz. This is the problem with most 2-way designs though. If you want a woofer to run higher you sacrifice the lower end. Its easier to push a horn tweeter lower and maybe get a 2-way. Something like TAD-2001 could run down to 500Hz, I think?
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Consider Manger and a couple of 10" drivers perhaps?
Its not going to be 'econo' tho.
With regard to 2" CDs John_E_Janowitz had this to say in this post:
Hell yes! Those Mangers ain't cheap, but neither are a couple of my friends 😉
Going to be building a couple of studios shortly... already bought drivers for one of them (Tempest X-15s, Ex-Anarchy's, Morel Tweeters)... been in storage for a few months, but the project should take off soon. For another studio which my mentor is designing for me, we are looking at Mangers + 2235H... but the 2235H is a pain to get hold of...The TD15H was being considered, but for reasons best rested, we are looking at other options.
In this one case we just might be able to afford the Mangers, but I have to keep other options open. Still looking for that elusive 15" woofer, usable to >1 KHz with an Fs of below 20 Hz.
Hell yes! Those Mangers ain't cheap, but neither are a couple of my friends 😉
Going to be building a couple of studios shortly... already bought drivers for one of them (Tempest X-15s, Ex-Anarchy's, Morel Tweeters)... been in storage for a few months, but the project should take off soon. For another studio which my mentor is designing for me, we are looking at Mangers + 2235H... but the 2235H is a pain to get hold of...The TD15H was being considered, but for reasons best rested, we are looking at other options.
In this one case we just might be able to afford the Mangers, but I have to keep other options open. Still looking for that elusive 15" woofer, usable to >1 KHz with an Fs of below 20 Hz.
If you can actual hear differences above 15KHz, congrats 😉
The bigger problem is the directivity issue with the 2" CDs and people can just add a super tweeter or 1/2" CD/tiny horn solution on top if it bothers them.
A couple of reason to go with a 2" CD
1. When you want 100% phase coherence between 500Hz and 10KHz. One horn,one CD running that range will give you the best phase coherence possible, XOs are nasty, removing them is a bonus.
2. You can not run a woofer from 20Hz to 1kHz without issues. Its just one of laws of physics things so moving the horn design down to 500Hz gives us more options.
That 15" woofer is elusive because it breaks some laws of physics 😉 btw, why do you need an Fs below 20Hz?? You can port a woofer with an Fs of 25Hz below 20Hz easily. I already posted about the AV15X driver above. Have you seen the full measurements up to 1KHz on that driver. Its the only driver I have seen that has the Xmax to produce 20Hz and the linearity to run up to 1Khz.
Im a fan of what John does, its obvious from the fact that I have purchased many,many drivers from him and Im waiting on the AV series to be sold again because I need 2 more. Speaking of AESpeakers.com maybe you should look at the measurements of the TD18H....it will do bass, I just do not know how high it runs.
The bigger problem is the directivity issue with the 2" CDs and people can just add a super tweeter or 1/2" CD/tiny horn solution on top if it bothers them.
A couple of reason to go with a 2" CD
1. When you want 100% phase coherence between 500Hz and 10KHz. One horn,one CD running that range will give you the best phase coherence possible, XOs are nasty, removing them is a bonus.
2. You can not run a woofer from 20Hz to 1kHz without issues. Its just one of laws of physics things so moving the horn design down to 500Hz gives us more options.
That 15" woofer is elusive because it breaks some laws of physics 😉 btw, why do you need an Fs below 20Hz?? You can port a woofer with an Fs of 25Hz below 20Hz easily. I already posted about the AV15X driver above. Have you seen the full measurements up to 1KHz on that driver. Its the only driver I have seen that has the Xmax to produce 20Hz and the linearity to run up to 1Khz.
Im a fan of what John does, its obvious from the fact that I have purchased many,many drivers from him and Im waiting on the AV series to be sold again because I need 2 more. Speaking of AESpeakers.com maybe you should look at the measurements of the TD18H....it will do bass, I just do not know how high it runs.
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I don't know about "differences", but when generating sine waves, I can hear up to 18 KHz, my partner at work can hear up to 15 KHz (we are in our mid 30s) and a young female friend of mine can hear 19.5 KHz, every single time!
Don't know if I do! What I do know is that the 2235H has an Fs in that range and it is favoured by the speaker designs that inspire me... always ready to learn, though...
Here is where I am wondering if the alternate might be the truth.
Kinoshitas and Reflexion Arts 239X are vaguely my inspirations.
An externally hosted image should be here but it was not working when we last tested it.
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Yes, according to spec. Huge cabs tho'... The RA209 does 25-20, but the 209X with the same driver complement, does 20-20 in a 400L cab!
The particular Kinoshita shown (RM7-VC) also does 20 Hz.
well its the holy threesome. cabinet volume - bass extension - sensitivity. You can have two if you sacrifice one other.
Deep bass and high sensitivity means a very large box.
Deep bass in small box means lower sensitivity.
High sensitivity in small box means poor bass extension.
"Cant change the laws of physics captn" =)
Deep bass and high sensitivity means a very large box.
Deep bass in small box means lower sensitivity.
High sensitivity in small box means poor bass extension.
"Cant change the laws of physics captn" =)
,
Well... thats the way I want to roll. I believe the Kinoshitas can be driven by a SET amplifier, though I'm planning on nothing so esoteric... might even go with Class D where power is not a problem... Since the boxes will be in-wall there should be no shortage of space as far as height and width is concerned...
as for the high freq usage for the sb12 and 15 they seem to be able to run 500 and 300 Hz. Their breakup seem benign at a start so they might even be run higher in the right implementation, at least in the 12 inch.
4 x JXR6 or 2 xMark Audio CHR 70s per side and just use a peerless XXLS 12" as a sub, below 20 hz f3, one of the best
830845 - Peerless XXLS-308-8 12 inch long stroke woofer with die-cast basket - Europe Audio
830845 - Peerless XXLS-308-8 12 inch long stroke woofer with die-cast basket - Europe Audio
RD-75 rolls off at approx 150 Hz in dipole without any baffle, which is quite sensational!
Very very long thread here:
http://www.diyaudio.com/forums/multi-way/142015-my-open-baffle-dipole-beyma-tpl-150-a.html
Go to the last page, and then backwards....
Also take a look at the monitors in that studio.
Michael Bolton's photo "In the studio with the incredibl?" on WhoSay
The big monitors seem to have toed in bass drivers. For better dispersion and bigger sweetspot?
Also mention the horn size and proportions.
By the way Michael Bolton's are always nice and always have deep bass notes. Some better, some even better, but he has never betrayed good sound in the way many other performers have did it.
He has some very nice records with Capitol studios.
Capitol Studios & Mastering
Again in all studios A, B and C same alignment of bass drivers, again two way and again horisontal wide and narrow horn.
Maybe they are after the effect of that Sansui
Actually quite allot Sansuis have midranges arranged like that. The question is why woud someone toe in bass drivers like that.
Michael Bolton's photo "In the studio with the incredibl?" on WhoSay
The big monitors seem to have toed in bass drivers. For better dispersion and bigger sweetspot?
Also mention the horn size and proportions.
By the way Michael Bolton's are always nice and always have deep bass notes. Some better, some even better, but he has never betrayed good sound in the way many other performers have did it.
He has some very nice records with Capitol studios.
Capitol Studios & Mastering
Again in all studios A, B and C same alignment of bass drivers, again two way and again horisontal wide and narrow horn.
Maybe they are after the effect of that Sansui
Actually quite allot Sansuis have midranges arranged like that. The question is why woud someone toe in bass drivers like that.
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