I rather like Dennis's (catapult's) modeling here for a mult-driver crossover:
HTGuide Forum - Duelund meets Dunlavy (aka Duelund meets transient perfect)
HTGuide Forum - Duelund meets Dunlavy (aka Duelund meets transient perfect)
Paul,
Basically I agree. But limitless headroom can't be achieved by building setup so big you can't position it properly in your room or WAF runs too low. In my case WAF = not found so it's pretty much up to me what size and looking setup I want to use myself. But still I have to consider what kind of setup can I use in my room and how do I have to position them to get most out of it.
I'll try to measure some room responses today with simple 1-way 25W sealed box. Just to find out where monopole bass setup should be positioned and are those positions possible. Naturally both WWMT and WMTMW are different than single woofer but I thought to measure anyway. Single woofer is kind of worst case scenario and actual constructions are just better.
Anyway I think I'll be going for full scale with WMTMW if it's WMTMW I'll be going. This means 15" pro woofers and massive cabinets. With WWMT I'll stick with 25W Scans.
Scott,
Digital filters also allow very good impulse responses. For example Behringer DCX-2496 basic model has that LaCleach setup possible where you can adjust delays, phasing and crossovers to have actually 3rd order filters with very good impulse response. Actually this approach has also crossed my mind. Especially with WMTMW using sealed pro woofers.
Basically I agree. But limitless headroom can't be achieved by building setup so big you can't position it properly in your room or WAF runs too low. In my case WAF = not found so it's pretty much up to me what size and looking setup I want to use myself. But still I have to consider what kind of setup can I use in my room and how do I have to position them to get most out of it.
I'll try to measure some room responses today with simple 1-way 25W sealed box. Just to find out where monopole bass setup should be positioned and are those positions possible. Naturally both WWMT and WMTMW are different than single woofer but I thought to measure anyway. Single woofer is kind of worst case scenario and actual constructions are just better.
Anyway I think I'll be going for full scale with WMTMW if it's WMTMW I'll be going. This means 15" pro woofers and massive cabinets. With WWMT I'll stick with 25W Scans.
Scott,
Digital filters also allow very good impulse responses. For example Behringer DCX-2496 basic model has that LaCleach setup possible where you can adjust delays, phasing and crossovers to have actually 3rd order filters with very good impulse response. Actually this approach has also crossed my mind. Especially with WMTMW using sealed pro woofers.
Member
Joined 2003
I don't remember what SW you have, and you may already know about these, but here is a link to some free tools. RRC simulates two woofers in-room...easier than balancing a speaker on a ladder🙂. ARPE, BDS, etc are also very useful.
FRD consortium link,tools - Speakerplans.com Forums
The approach Dennis outlines looks good. I had forgotten about JMMLC's work with the DCX...do you have a link you can share?
FRD consortium link,tools - Speakerplans.com Forums
The approach Dennis outlines looks good. I had forgotten about JMMLC's work with the DCX...do you have a link you can share?
I hadn't read you were utilizing the Behringer. 😱
Note however that you could do a "combo": i.e. an exceedingly simple 1st order electrical passivly at amp input, and ALSO add-in the additional "trailing" filters via the Behringer. In fact, I don't think anyone has ever done something like that before. 🙂
I vaguely remember Jean Michel's design.. couldn't find it again in English. 🙁
Intresting.
Here it is:
Expanded Soundstaging and 3D-Imaging
I'll try to experiment this with my present dipoles today. Perhaps I can blow some life into them.
I got a .frd file out of that selfextracting .exe, not xls spreadsheet.
Actually I can simulate many of them with LspCAD but I don't know how accurate it is. I'll find out tonight while I try to position subwoofer into my room. Borrowed it just for testing how monopole works in this one. Yesterdays testing didn't look promissing. About +20dB bump 30-40Hz.
Strange. LaCleach xls sheet gives rather large delay numbers. For example 250Hz and 1500Hz crossoverpoints give appropriate cutoff frequences for the crossover but then 50mm and 70mm measured (for example) delay setting give LaCleach delays over 350mm and over 450mm. Is this correct and just part of the "magic"?
Yep. That appeared to be correct. So with steep crossover slopes it indeed means rather significant delays.
I did some room measurements yesterday. It seems that adding a subwoofer into a 3-way isn't really that simple. Even response can be matched but it still didn't sound that good. Goes simply too complicated and why not, many people settle with 2-ways, maybe assisted with a single subwoofer in this size rooms.
Simplest change in configuration would be try a WMTMW with pretty much present drivers in a closed cabinet arragement. In a 20m2 room, can twin 25W Scan Speaks really deliver and keep up? According to raw simulation they run out of linear excursion around 99-100dB plus room boost. I guess that's pretty close to 110dB levels then.
Scans work in my present dipoles just fine but naturally with very low loss suspension there is a risk of overdriving their excursion capabilities and without actual woofers (like it's "father" Beethoven) bass department is left short compared to other ranges.
Scan Speak - Excel based WMTMW would be narrow and slim compared to full scale 15" PA woofer setup. Perhaps looking something like Dynaudio Confidence C4 which I like visually.
What do you think, how much pair of 10" Scans can take?
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Joined 2003
If you couldn't get a subwoofer to sound good, I suspect the room or the subwoofer/enclosure itself. Does your room have very stiff walls? Bass traps or other treatment? Distributing multiple subs (like WMTMW approach) can improve sound a lot.
Only you can decide if 4x10" Scans are enough. Low bass would certainly be much more extended and "solid" sounding with sealed boxes than with your current dipoles. If you build modules, you can change to 15" if you are not satisfied with 10". Build tall 10" modules so that 15" can be substituted later with no change in tweeter height.
Only you can decide if 4x10" Scans are enough. Low bass would certainly be much more extended and "solid" sounding with sealed boxes than with your current dipoles. If you build modules, you can change to 15" if you are not satisfied with 10". Build tall 10" modules so that 15" can be substituted later with no change in tweeter height.
I think WMTMW should be equally wide along it's entire lenght. Therefore 10" WMTMW should be as wide as 15" driver requires if I want a 15" option there.
Yep walls are hard. Concrete almost all. No special treatment so far. 35Hz and 95Hz are primary room modes. 35Hz is a problem both monopole and dipole design. I'll try to measure dipoles some more tonight.
I also got a "maybe" idea today. Basically I think I bite too large chunk by trying to build Beethoven style 4-ways. Totally overkilling in this size room and it makes overall equation very hard to handle. Therefore it's possible that I'll never get it just right. Primary problem with present setup is limited dynamics and SPL from my woofers (which were meant as low midrange in the final setup). Twin W18 can play helluva levels with 250Hz highpass and tweeter isn't in pain either.
So the idea. How about taking most or propably all of the good things in my currect setup and patch up more where it's weak. Saw off the Scan Speak part of my panels, stick twin W18 with my present aluminium or Esotar or maybe even ribbon (like Fountek Pro5i if it's good) in a simple Linkwitz Phoenix style MTM piece. Then replace Scan Speak bass apartment with larger panel using for example six 12" Peerless SLS units. Along sidewalls radiating to 1/4 space it would give rather massive +23dB (theoretical) addition to under 250Hz range. As simple example this means the SPL what my twin Scans could deliver with maximum +-6,5mm linear excursion would cause that pile of 12" move only +-0,5mm...
Yep walls are hard. Concrete almost all. No special treatment so far. 35Hz and 95Hz are primary room modes. 35Hz is a problem both monopole and dipole design. I'll try to measure dipoles some more tonight.
I also got a "maybe" idea today. Basically I think I bite too large chunk by trying to build Beethoven style 4-ways. Totally overkilling in this size room and it makes overall equation very hard to handle. Therefore it's possible that I'll never get it just right. Primary problem with present setup is limited dynamics and SPL from my woofers (which were meant as low midrange in the final setup). Twin W18 can play helluva levels with 250Hz highpass and tweeter isn't in pain either.
So the idea. How about taking most or propably all of the good things in my currect setup and patch up more where it's weak. Saw off the Scan Speak part of my panels, stick twin W18 with my present aluminium or Esotar or maybe even ribbon (like Fountek Pro5i if it's good) in a simple Linkwitz Phoenix style MTM piece. Then replace Scan Speak bass apartment with larger panel using for example six 12" Peerless SLS units. Along sidewalls radiating to 1/4 space it would give rather massive +23dB (theoretical) addition to under 250Hz range. As simple example this means the SPL what my twin Scans could deliver with maximum +-6,5mm linear excursion would cause that pile of 12" move only +-0,5mm...
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Joined 2003
Think I misunderstood you. I thought you were talking about a 3-way WMTMW with Esotar, Excel, and either Scan or 15" woofers...didn't realize you were talking 4-way. There should be several 15" pro woofers with good performance up to 200-250, so I think a 3-way is possible. With lower output, sealed Scans might be okay too.
The 12" SLS is a good driver, especially considering price...but it does require a big box. Are you thinking dipole SLSs?
Another option would be to keep your current Scan/Excel/Esotar dipoles as-is and build one or more driver columns for low bass. Distributed subwoofer concept helps smooth response around the room and vertical/up is an equally viable direction for source distribution.
Concrete room is tough for good bass. It will probably take a lot of careful treatment.
The 12" SLS is a good driver, especially considering price...but it does require a big box. Are you thinking dipole SLSs?
Another option would be to keep your current Scan/Excel/Esotar dipoles as-is and build one or more driver columns for low bass. Distributed subwoofer concept helps smooth response around the room and vertical/up is an equally viable direction for source distribution.
Concrete room is tough for good bass. It will probably take a lot of careful treatment.
I propably wrote things a bit wrong..
So my present speakers are Beethoven based WWMTM dipoles with Seas aluminium, Seas W18 and 25W Scans. Like I wrote in initial message in this thread I'm not perfectly satisfied with them and like I now mensioned it propably was too big bite to go for 4-way. I've tried few monopole solutions with the present speakers but haven't get them working that well.
This left me to thought that why not build something totally new which this WMTMW idea with either present Scans or 15" Pros in sealed cabinet.
But since I like some of the features in my present setup this drove me to conclusion why shouldn't I just upgrade and simplify their design. I don't see that much sense adding up a pile of 25W Scan Speaks. Up to 200-250Hz that I've been using so far SLS Peerless 12" runs just fine. So compared to present 2x25W in each side 6x12" SLS would give dramatical improvement with bottom octaves and the basic speaker would remain the same.
Using my Behringer with MTM top and separated WWWWWW column it's possible to basically do the same that people do with separated subwoofers. Place woofers where their range is ideal and hit MTM top where I want the listening triangle. Little like satellites with subwoofer. This also leave the system relatively simple compared to present 3-way plus something thought.
What do you think about using sand in cabinet damping? Is it a good solution? Leaving some space between cabinet walls and fill them later with fine sand. Or is there more efficient ways?
Driver selection. I have four W18E001 Seas Excels in my present dipoles. Excellent but also limited by their breakup:
THE ART OF SOUND PERFECTION BY SEAS - E0018-08S W18E001
My drivers are actually older model where Le is marked to be 0,40mH.
In the opposite corner Eighteen Sound 8NMB420:
8NMB420 - High Output MB Neodymium Driver
Response looks smooth, Le is low, good efficiency..
W18 vs 8NMB. What do you think?
Range would be from 120-150Hz up to 1200-1600Hz. MTM configuration, Fountek Pro5i tweeter.
THE ART OF SOUND PERFECTION BY SEAS - E0018-08S W18E001
My drivers are actually older model where Le is marked to be 0,40mH.
In the opposite corner Eighteen Sound 8NMB420:
8NMB420 - High Output MB Neodymium Driver
Response looks smooth, Le is low, good efficiency..
W18 vs 8NMB. What do you think?
Range would be from 120-150Hz up to 1200-1600Hz. MTM configuration, Fountek Pro5i tweeter.
Thanks! Looks like no-go on the Eighteen Sound:
18Sound 8NMB420 :: THD_96-100dB_14inches.jpg picture by augerpro - Photobucket
96-100dB but is it at 14" distance or are levels normalized to match 96-100dB @ 1m (40") distance?
Neither way it doesn't look that good. 3rd harmonic is dominant and up to 1kHz or so THD is around 1% or even above. Looks like good old Seas Excel beats those drivers pretty badly when it comes to distorsion. I know W18 has limited top end extension but below that they are pretty good units.
Or do you have different visions from these measurements?
Make your own decision. I wouldn't use driver with the high Q 12dB resonance of the Seas. Also, be very careful taking different people's measurements as equivalent. They are not. Zaph makes this good point on his site.
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Joined 2003
Hi Jussi,
Haven't tried sand cabinets myself, but think they should work well. I'd build good solid cabinets by the basics and use sand as a bonus improvement.
The 18Sound midrange drivers with Active Impedance Control are quite good but, between the Excel and 8NMB420, I agree SEAS looks like the better choice.
Haven't tried sand cabinets myself, but think they should work well. I'd build good solid cabinets by the basics and use sand as a bonus improvement.
The 18Sound midrange drivers with Active Impedance Control are quite good but, between the Excel and 8NMB420, I agree SEAS looks like the better choice.
I know measurements aren't directly comparable and the only way to be absolutely sure is buying couple samples and test them myself but since it's pretty much a matter of choosing between those two I don't want to take the risk.
W18 has it's peaks but by crossing low enough with steep crossover they can be avoided. 1200Hz 4th order should work pretty well. Naturally most projects with this driver run it at least or even more that octave higher and there it's marely average driver and compared to it's price even rather poor performer.
I'll attach W18E001 distorsion measurement. Rated SPL is 90dB but as you can see midrange level reaches about 95dB.
Yep. I'll have to see how my prototype woofer columns work out. I scetched S-baffle dipoles to Peerless 830669 (SLS 12"). 280x387x720mm that contains two woofers. Let's see how it works out. I'd used 200Hz or higher crossoverpoint but I don't think it's going to work that high. 150Hz is more propable. When it comes to cabinet proportions I'd rather use deeper columns, something around 460-480mm, but that limits the range even more. This is why I considered using 8" midrange units but at least 18Sound turned me down.
Yep. That would propably lead for 10-12" midrange in a single midrange setup. MTM with even W18 is rather tall when it comes to pointing tweeter at ear height and use 720mm high woofer columns. And those S-baffles with 12" woofers just couldn't be any smaller in height.
Attachments
Ok. So present thought is to experiment 830669 Peerless woofers in 387mm (15,2") deep S-baffle and see how wide range they can play. I'd hope for 200Hz but I think 150Hz usable top limit is more propable. I'd make them even deeper and therefore gain couple dB more SPL capacity but it lowers the range even more.
Overall setup, if woofers seem promissing, is WWMTMWW. 830669 woofers 20-150Hz S-baffle (dipole), W18E Seas mids 150-1200Hz (acoustic resistance cabinet, cardioid) and finish the job with waveguided Fountek Pro5i.
Here is the raw un-eqd distorsion from Pro5i. 2nd to 5th harmonics included. SPL is normalised to 95dB @ 4kHz. Drop between 1,2-3kHz is baffle edge diffraction.
Overall setup, if woofers seem promissing, is WWMTMWW. 830669 woofers 20-150Hz S-baffle (dipole), W18E Seas mids 150-1200Hz (acoustic resistance cabinet, cardioid) and finish the job with waveguided Fountek Pro5i.
Here is the raw un-eqd distorsion from Pro5i. 2nd to 5th harmonics included. SPL is normalised to 95dB @ 4kHz. Drop between 1,2-3kHz is baffle edge diffraction.
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