Yup, the RS150-8 looks like it would work fine. About 20L ported for a pair of them. Only drawback I can see is that a larger driver may be deeper in depth - 73.5mm for the RS150.
Another occasion where I have to correct myself.
By going in-wall, you don't lose 6dB to baffle step loss, and when you put two 8ohm drivers in parallel, you gain 6dB in sensitivity, so with one RS150-8 at almost 89dB in sensitivity, 2 of them in parallel are going to give you about 95dB, which your tweeter selection (which is a good one by the way) won't be able to keep up with.
If you run two 4ohm drivers in series, there is no net gain in sensitivity. So you should be looking for 8ohm drivers with a max sensitivity of about 86dB or 4ohm drivers with a max of 92dB. In this case, the RS150-4 will work for you.
I have 2 more thoughts though. For home theater and better blending with a sub, the more gradual, 2nd order rolloff that you get with a sealed design for L/C/R generally does a better job. Sealed gives you better transients too. Plus you don't have to mess around with port tuning. And if you are trying to stay close to the cabinet dimensions you used in your 1st post, it looks like a Vb of 10L might be a better goal to shoot for. Or not - maybe you have some flexibility there, I'm not sure.
Given all of that, here's what I would go with:
SB 15NAC30-8
Sensitivity = 85.5dB
F3 = 79Hz in 8L sealed and heavily stuffed with Q=.692, perfect for handing off to a sub.
$46 (Cnd on sale at 50% off)
Here's a build with the driver's bigger 6.5" brother just to give you some idea of the quality of these drivers - SBAcoustics-61-NAC
The 1 negative (is it?) - you have to order from Canada, but unlike when I order from the States, I don't believe there's any extra tax or duties for you to pay (I could be wrong there - maybe someone in the States can confirm that?). And you do get the advantage of the low Canadian dollar.
By going in-wall, you don't lose 6dB to baffle step loss, and when you put two 8ohm drivers in parallel, you gain 6dB in sensitivity, so with one RS150-8 at almost 89dB in sensitivity, 2 of them in parallel are going to give you about 95dB, which your tweeter selection (which is a good one by the way) won't be able to keep up with.
If you run two 4ohm drivers in series, there is no net gain in sensitivity. So you should be looking for 8ohm drivers with a max sensitivity of about 86dB or 4ohm drivers with a max of 92dB. In this case, the RS150-4 will work for you.
I have 2 more thoughts though. For home theater and better blending with a sub, the more gradual, 2nd order rolloff that you get with a sealed design for L/C/R generally does a better job. Sealed gives you better transients too. Plus you don't have to mess around with port tuning. And if you are trying to stay close to the cabinet dimensions you used in your 1st post, it looks like a Vb of 10L might be a better goal to shoot for. Or not - maybe you have some flexibility there, I'm not sure.
Given all of that, here's what I would go with:
SB 15NAC30-8
Sensitivity = 85.5dB
F3 = 79Hz in 8L sealed and heavily stuffed with Q=.692, perfect for handing off to a sub.
$46 (Cnd on sale at 50% off)
Here's a build with the driver's bigger 6.5" brother just to give you some idea of the quality of these drivers - SBAcoustics-61-NAC
The 1 negative (is it?) - you have to order from Canada, but unlike when I order from the States, I don't believe there's any extra tax or duties for you to pay (I could be wrong there - maybe someone in the States can confirm that?). And you do get the advantage of the low Canadian dollar.
Regarding cabinet dimensions: I think I can probably get away with an internal depth of 6", a width of 13", and they can be as tall as I need them to be.
It's a complete departure from my initial design (which I'm not at all married to), but what are your thoughts on going with:
Dayton Audio RS225-4
B&C DE10-8
SEOS-8 Waveguide
(I've read that the Denovo DNA-205 is a clone of the B&C DE10 -- and I'm assuming it's cheaper -- but I can't find it for sale anywhere other than in kits.)
I would use a single RS225 in a sealed enclosure. The tweeter is far more sensitive than the woofer, but am I correct in thinking that I can just attenuate it?
It's a complete departure from my initial design (which I'm not at all married to), but what are your thoughts on going with:
Dayton Audio RS225-4
B&C DE10-8
SEOS-8 Waveguide
(I've read that the Denovo DNA-205 is a clone of the B&C DE10 -- and I'm assuming it's cheaper -- but I can't find it for sale anywhere other than in kits.)
I would use a single RS225 in a sealed enclosure. The tweeter is far more sensitive than the woofer, but am I correct in thinking that I can just attenuate it?
An 8" + 1" can work but you need a tweeter that can cross over pretty low, like below 2kHz, which this one doesn't look like it can do comfortably. It could work with the right tweeter or make it a 3-way and add in a mid that can be crossed higher.
Also yes, the tweeter would just need to be padded down but that's a whole lot of dB that needs to disappear, like about 16dB. I'd try to go for a different tweeter that matches SPL a little better.
Also yes, the tweeter would just need to be padded down but that's a whole lot of dB that needs to disappear, like about 16dB. I'd try to go for a different tweeter that matches SPL a little better.
Hi JustinRT,
I agree that an 8" + 1" can be a very nice performer. Other then jReave's point on tweeter selection another consideration is the severity of the woofer breakup. In the case of Dayton RS225-4, it is quite severe. IMHO, a better woofer choice for a 2way like this would be Peerless 830869 Nomex cone or one of the Sb Acoustics offerings like the SB23NRX45-4. I can speak to the Peerless 830869. I'm using it in a two way crossed at 1.7K to a waveguide loaded tweeter and say it is a sweet woofer! Matter of fact, I like it so much that I'm going to order (2) more from Solen Canada and build a 2.5 way using these Peerless woofers wired in parallel.
Best Regards,
Rich
I agree that an 8" + 1" can be a very nice performer. Other then jReave's point on tweeter selection another consideration is the severity of the woofer breakup. In the case of Dayton RS225-4, it is quite severe. IMHO, a better woofer choice for a 2way like this would be Peerless 830869 Nomex cone or one of the Sb Acoustics offerings like the SB23NRX45-4. I can speak to the Peerless 830869. I'm using it in a two way crossed at 1.7K to a waveguide loaded tweeter and say it is a sweet woofer! Matter of fact, I like it so much that I'm going to order (2) more from Solen Canada and build a 2.5 way using these Peerless woofers wired in parallel.
Best Regards,
Rich
Hey Rich,
Thanks for the recommendations; those Peerless woofers look interesting, and look to currently be on sale at Solen.
jReave,
Is the implication that in an MTM configuration, I can set the crossover point higher? Do you think that I would be able to use two of the Peerless 830869 in Parallel (which would give me 96 dB sensitivity) with the B&C compression tweeter? From what I've read in another forum, the Denovo DNA-205 can be crossed over lower than the B&C DE10. I'm going to try to figure out if it's possible to purchase separate from a kit.
Thanks for the recommendations; those Peerless woofers look interesting, and look to currently be on sale at Solen.
jReave,
Is the implication that in an MTM configuration, I can set the crossover point higher? Do you think that I would be able to use two of the Peerless 830869 in Parallel (which would give me 96 dB sensitivity) with the B&C compression tweeter? From what I've read in another forum, the Denovo DNA-205 can be crossed over lower than the B&C DE10. I'm going to try to figure out if it's possible to purchase separate from a kit.
Ok, here's the way I look at home theater speakers:
1 - L/C/R should be as close to the same as possible. (Perfect with what you are doing.)
2 - Perhaps more than anything else (besides the subs) what I want is dialogue clarity. And at least 1 of the ways to get that is by relieving the mid driver from having to pull double duty, of having to also work like crazy on the bass at the same time. So, either limit the satellites to >80Hz or go with a 3-way, the latter in my mind being the better of the 2.
As to the larger woofers, besides looking out for cone breakup as montana mentioned, you also want to watch out for directivity, or the off-axis response. Not recommended is crossing over to the tweeter above the point where the woofer's off-axis response starts to diminish, the strict rule of thumb being cross below the woofer's -3dB point at 45 degrees off-axis.
There is another rule of thumb for driver spacing which says the centers of 2 drivers in an MTM should not be spaced larger than 1/2 the wavelength of the xo frequency. 1/4 wavelength is even better but 1 wavelength is often accepted as a compromise when necessary.
Looking at the Peerless FR below, the -3dB point at 45 degrees looks to be just about exactly where montana put his xo, about 1700Hz
. However, the corresponding wavelength is about 8", so unless you can get the centers of those 2 woofers closer than 4", it's a less than ideal setup. Even 8" center to center can't be done when there's a tweeter in between them. So 8" drivers are not generally recommended in MTM configurations.
Also those Peerless don't go any lower (ie. F3) sealed than the 5" SB's do. And they need a fairly large Vb for 2 of them ported, upwards of about 50L. You are going to want to double check if you have enough room for that.
Certainly for yourself but also for those of us trying to aid you, it really helps if you establish a set of goals or criteria or parameters to start off with, otherwise it's easy to just start bouncing around between a whole lot of different choices. Establish things like:
- budget
- maximum box size
- minimum F3, so stand alone for music or always with a sub
- max SPL at what distance
- minimum speaker sensitivity
- alignment: sealed or ported or....
- 2-way, 3-way, MTM, TMW, MTMWW, etc.....
- acceptable minimum impedance
- passive or active
- how much power available into how many ohms
- even where you are willing or not willing to buy from
etc....
Once you get these things sorted out, the task of driver selection and speaker design tends to fall into place a little bit more easily.
1 - L/C/R should be as close to the same as possible. (Perfect with what you are doing.)
2 - Perhaps more than anything else (besides the subs) what I want is dialogue clarity. And at least 1 of the ways to get that is by relieving the mid driver from having to pull double duty, of having to also work like crazy on the bass at the same time. So, either limit the satellites to >80Hz or go with a 3-way, the latter in my mind being the better of the 2.
As to the larger woofers, besides looking out for cone breakup as montana mentioned, you also want to watch out for directivity, or the off-axis response. Not recommended is crossing over to the tweeter above the point where the woofer's off-axis response starts to diminish, the strict rule of thumb being cross below the woofer's -3dB point at 45 degrees off-axis.
There is another rule of thumb for driver spacing which says the centers of 2 drivers in an MTM should not be spaced larger than 1/2 the wavelength of the xo frequency. 1/4 wavelength is even better but 1 wavelength is often accepted as a compromise when necessary.
Looking at the Peerless FR below, the -3dB point at 45 degrees looks to be just about exactly where montana put his xo, about 1700Hz
. However, the corresponding wavelength is about 8", so unless you can get the centers of those 2 woofers closer than 4", it's a less than ideal setup. Even 8" center to center can't be done when there's a tweeter in between them. So 8" drivers are not generally recommended in MTM configurations.Also those Peerless don't go any lower (ie. F3) sealed than the 5" SB's do. And they need a fairly large Vb for 2 of them ported, upwards of about 50L. You are going to want to double check if you have enough room for that.
Certainly for yourself but also for those of us trying to aid you, it really helps if you establish a set of goals or criteria or parameters to start off with, otherwise it's easy to just start bouncing around between a whole lot of different choices. Establish things like:
- budget
- maximum box size
- minimum F3, so stand alone for music or always with a sub
- max SPL at what distance
- minimum speaker sensitivity
- alignment: sealed or ported or....
- 2-way, 3-way, MTM, TMW, MTMWW, etc.....
- acceptable minimum impedance
- passive or active
- how much power available into how many ohms
- even where you are willing or not willing to buy from
etc....
Once you get these things sorted out, the task of driver selection and speaker design tends to fall into place a little bit more easily.
Attachments
Hi jReave,
I wanted to run a question by you to get your expert opinion. This may even be a design option for the OP. What do you think about a 2.5 way TWW configuration with upper woofer 25L sealed and lower woofer 58L vented? The woofers would be the Peerless 830869 and tweeter may remain the SS D2604/83300 mounted in Monacor WG300 or maybe look to something else that can be crossed around 1.2k or there about. This build we me strictly for music but I'm convinced that it would do well for HT use as well. I have attached a boxy cad drawing to get an idea of cab size, driver spacing, etc.
Also, have you written any books on loudspeaker design and theories? If so, where might I purchase a copy. I really have learned a lot from your posts.
Best Regards,
Rich
I wanted to run a question by you to get your expert opinion. This may even be a design option for the OP. What do you think about a 2.5 way TWW configuration with upper woofer 25L sealed and lower woofer 58L vented? The woofers would be the Peerless 830869 and tweeter may remain the SS D2604/83300 mounted in Monacor WG300 or maybe look to something else that can be crossed around 1.2k or there about. This build we me strictly for music but I'm convinced that it would do well for HT use as well. I have attached a boxy cad drawing to get an idea of cab size, driver spacing, etc.
Also, have you written any books on loudspeaker design and theories? If so, where might I purchase a copy. I really have learned a lot from your posts.
Best Regards,
Rich
Attachments
H
The crossover:
I am sure that I am completely out of my league in trying to design a crossover, but I gave it a shot anyway. I'm just going to post a bunch of graphs and hope that you guys can tell the ways that I screwed up (and hopefully how to fix it
Schematic:
3rd order crossovers use a lot of components that can do crazy things to the signal, as a sanity check get a cap and coil so you can run the drivers in first order, and compare to that.
jReave,
I don't know if the product specs on Parts Express are to be trusted, but for the Peerless 830869 it lists an optimum sealed cabinet volume of 0.57 ft^3, with an F3 of 67 Hz. That size of enclosure (or even twice the size if I'm using 2 woofers) is doable.
I'm not entirely opposed to building a 3-way speaker -- in fact, all things being equal, I'd probably prefer it. The reason that I'm hesitant is because I assume the crossover will be more complex. I don't know that I'll be able to properly design a 3-way crossover, and if it requires significantly more components, I'm worried that cost is going to skyrocket (I'd prefer to use polypropylene capacitors rather than electrolytic). That said, if it's not cost prohibitive, and I feel confident that I won't completely screw up the crossover design, I'd definitely be open to going with a 3-way design.
I had read about the ctc spacing, but either what I read was wrong -- or, more likely, I misunderstood -- as I was under the impression that the measurement that mattered was from the center of the woofer to the center of the tweeter.
To answer your questions:
Unless it's an absolutely horrible idea, I do think I'd like to use the compression tweeter with waveguide. I only have one row of seats, and can toe-in the speakers.
If I go with a 3-way design using a compression tweeter with waveguide, will the Peerless be a good choice as the woofer? What should I be looking for in a midrange to pair with it?
I'm truly grateful for all the help you and everyone else who has replied are giving me.
I don't know if the product specs on Parts Express are to be trusted, but for the Peerless 830869 it lists an optimum sealed cabinet volume of 0.57 ft^3, with an F3 of 67 Hz. That size of enclosure (or even twice the size if I'm using 2 woofers) is doable.
I'm not entirely opposed to building a 3-way speaker -- in fact, all things being equal, I'd probably prefer it. The reason that I'm hesitant is because I assume the crossover will be more complex. I don't know that I'll be able to properly design a 3-way crossover, and if it requires significantly more components, I'm worried that cost is going to skyrocket (I'd prefer to use polypropylene capacitors rather than electrolytic). That said, if it's not cost prohibitive, and I feel confident that I won't completely screw up the crossover design, I'd definitely be open to going with a 3-way design.
I had read about the ctc spacing, but either what I read was wrong -- or, more likely, I misunderstood -- as I was under the impression that the measurement that mattered was from the center of the woofer to the center of the tweeter.
To answer your questions:
- I'd like to keep the cost of all the components (including crossover but excluding enclosure materials) to around $500.
- Maximum box size: internal depth of 6" (15.25cm), width of 13" (33cm), and they can be as tall as I need them to be.
- They will always be used with a sub.
- Seating will be ~15ft (4.5m); I don't have a specific number for max SPL in mind, but it would be nice to be able to get quite loud on occasion. Also the subs they will be paired with are four 18" woofers in an infinite baffle.
- I'm not sure about minimum sensitivity. They will be used mostly for movies, and as I said, ideally they will be capable of playing loud when needed.
- I would prefer a sealed enclosure if possible, but have no problem going ported if necessary.
- If it's within my capabilities and budget, I'd love to go 3-way (TMW, probably), otherwise, I'll have to stick with a 2-way design.
- The speaker can't be lower than 4 ohms. If an 8 ohm design will meet my criteria, all the better.
- I will almost certainly be going passive. I'd love to go active, but (correct me if I'm wrong) I believe that would require me to have a separate amp for each channel.
- The speakers will be driven by an AVR. Currently I have a Pioneer SC-1522-k. The power rating is listed as: 130w per channel @ 8 ohms; however, it says it supports 4 ohm speakers. I will be getting a new AVR eventually, but it will be at least as good as my current AVR.
Unless it's an absolutely horrible idea, I do think I'd like to use the compression tweeter with waveguide. I only have one row of seats, and can toe-in the speakers.
If I go with a 3-way design using a compression tweeter with waveguide, will the Peerless be a good choice as the woofer? What should I be looking for in a midrange to pair with it?
I'm truly grateful for all the help you and everyone else who has replied are giving me.
The more simple the design, the better, as far as I'm concerned.
When I go to design the new crossover, I'll definitely try to do better and get it done with fewer components.
Which just goes to show you need to be bloody careful. Because 1st order cap & coil rarely works well at the best of times, and is about the worst idea that it is humanly possible to conceive with the XT25. Steve has hinted at this in a related manner, I'll go further:
-The XT25 does a lot of things very well. Used properly, it's a limited dispersion tweeter with a very flat response and low distortion > 2KHz. However, it is effectively a 3/4in tweeter in terms of its radiating area. It may have an extended LF response, but that does not mean it is a good idea to cross it low. It isn't. Distortion rockets < 2KHz.
-1st order filters cannot prevent driver excursion increasing below the crossover frequency. That's not opinion, it's a law of [electro] mechanical engineering. You may be able to mitigate this with waveguide loading boosting LF efficiency (also lowering distortion); this is a separate matter entirely though. Assuming unmodified direct radiators on a flat baffle, the slow rolloff of 1st order slopes coupled with increasing excursion = high distortion.
3rd order filters don't do crazy things to the signal if they're properly designed, and they don't necessarily use 'a lot of components'. To do a 1st order with an XT25 well, depending on the filter frequency it's quite possible you'd end up needing more components, not fewer, as you'd have to hurl an Fs LCR Zobel at it for a start if you don't fancy listening to it howling like a banshee, and likely some additional response shaping as well.
-The XT25 does a lot of things very well. Used properly, it's a limited dispersion tweeter with a very flat response and low distortion > 2KHz. However, it is effectively a 3/4in tweeter in terms of its radiating area. It may have an extended LF response, but that does not mean it is a good idea to cross it low. It isn't. Distortion rockets < 2KHz.
-1st order filters cannot prevent driver excursion increasing below the crossover frequency. That's not opinion, it's a law of [electro] mechanical engineering. You may be able to mitigate this with waveguide loading boosting LF efficiency (also lowering distortion); this is a separate matter entirely though. Assuming unmodified direct radiators on a flat baffle, the slow rolloff of 1st order slopes coupled with increasing excursion = high distortion.
3rd order filters don't do crazy things to the signal if they're properly designed, and they don't necessarily use 'a lot of components'. To do a 1st order with an XT25 well, depending on the filter frequency it's quite possible you'd end up needing more components, not fewer, as you'd have to hurl an Fs LCR Zobel at it for a start if you don't fancy listening to it howling like a banshee, and likely some additional response shaping as well.
Last edited:
Justin,
Thanks for the detailed response. That's going to help a lot.
PE is close to what I get with Unibox for the 8" Peerless - 12 to 16L sealed with F3 71 to 79Hz depending on stuffing.
With CTC spacing, you are correct - when 2 drivers handle the same frequencies, that rule applies usually for the mid and tweeter. But in an MTM, there are actually 3 drivers handling the same frequencies at the xo instead of just 2 so now the rule has to apply to the spacing between the 2 mids as well.
I do actually think the compression tweeter is a bad idea. I suspect that you are worried about something (SPL?) that you don't have to be. Your 1st selection is a good choice but it does have to be treated carefully in terms of the xo frequency and in the xo with more parts for an LCR impedance flattening notch. I may look at others tweeters if necessary.
If these speakers are going to be in-wall, I'm not sure how you are going to toe them in unless you angle the wall on the sides. Not impossible actually but not completely necessary. You can decide on that one. But it is actually going to be important that the front baffles are flush with your walls. That can seriously simplify the xo and improve SQ by avoiding all diffraction effects and will gain you a generous 6dB advantage due to no baffle step loss.
I like a 3-way for you but yes, it's a more expensive xo. Not necessarily more complex, just twice as many components or so. For 3 speakers depending on xo complexity you might be spending about $200 on xo parts. Perhaps counter intuitively, I kind of find it easier to fine tune a 3-way than a 2-way as you have more focused control over the overall balance (separate bass, mid and treble sections) by basically just altering the resistors on the mid and/or tweeter.
But whether it's a 2-way or 3-way, success is really pretty much dependent on you being able to take good FR and Z measurements once the speakers are build and in place. Given those files, simulating a xo becomes very accurate and myself and/or others can do that or give you a hand doing it yourself. Might be a good idea then before purchasing anything to download something like REW, get it set up and give it a go with your AVR mic. You might want to be comfortable with that before you proceed much further. Attached is some info on measuring when you're ready.
I'm going to look over drivers for you, but I keep going back to Solen because of all the sales they have on high quality drivers. So maybe you might want to just double check if there are any hidden cost ordering from Canada or if the shipping costs make negate the extra savings. That way I'll know if my selections are staying within your budget or not.
Thanks for the detailed response. That's going to help a lot.
PE is close to what I get with Unibox for the 8" Peerless - 12 to 16L sealed with F3 71 to 79Hz depending on stuffing.
With CTC spacing, you are correct - when 2 drivers handle the same frequencies, that rule applies usually for the mid and tweeter. But in an MTM, there are actually 3 drivers handling the same frequencies at the xo instead of just 2 so now the rule has to apply to the spacing between the 2 mids as well.
I do actually think the compression tweeter is a bad idea. I suspect that you are worried about something (SPL?) that you don't have to be. Your 1st selection is a good choice but it does have to be treated carefully in terms of the xo frequency and in the xo with more parts for an LCR impedance flattening notch. I may look at others tweeters if necessary.
If these speakers are going to be in-wall, I'm not sure how you are going to toe them in unless you angle the wall on the sides. Not impossible actually but not completely necessary. You can decide on that one. But it is actually going to be important that the front baffles are flush with your walls. That can seriously simplify the xo and improve SQ by avoiding all diffraction effects and will gain you a generous 6dB advantage due to no baffle step loss.
I like a 3-way for you but yes, it's a more expensive xo. Not necessarily more complex, just twice as many components or so. For 3 speakers depending on xo complexity you might be spending about $200 on xo parts. Perhaps counter intuitively, I kind of find it easier to fine tune a 3-way than a 2-way as you have more focused control over the overall balance (separate bass, mid and treble sections) by basically just altering the resistors on the mid and/or tweeter.
But whether it's a 2-way or 3-way, success is really pretty much dependent on you being able to take good FR and Z measurements once the speakers are build and in place. Given those files, simulating a xo becomes very accurate and myself and/or others can do that or give you a hand doing it yourself. Might be a good idea then before purchasing anything to download something like REW, get it set up and give it a go with your AVR mic. You might want to be comfortable with that before you proceed much further. Attached is some info on measuring when you're ready.
I'm going to look over drivers for you, but I keep going back to Solen because of all the sales they have on high quality drivers. So maybe you might want to just double check if there are any hidden cost ordering from Canada or if the shipping costs make negate the extra savings. That way I'll know if my selections are staying within your budget or not.
Hi Rich,
First I would double check your modeling, as I think you've modeled for 2 drivers instead of one for each of those chambers.
Going sealed and ported is a little unusual in a 2.5-way design, but it could work if you are looking for a LF response in between a sealed and ported alignment. But I would design in more flexibility and go with 2 chambers, both ported. Then stuff 1 of the ports if you want to play around with that LF response. More options this way, say if wanted to move to a bigger room later.
However, 2.5-ways are still a bit of a compromise in that 1 of the midwoofers is still handling the whole frequency range from somewhere around 40Hz up to 1 or 2kHz. Actually, what I think you are ready for is to step up to the big leagues and go 3-way with say 2 of those Peerless as woofers and throw in a 5" Revelator or Satori as your mid. Now we're talking.
The 3-way also gives you the added advantage of treating your mid and woofer chambers differently in terms of resonances and absorption - something that's much harder to do when a driver is covering a much wider frequency range.Also, have you written any books on loudspeaker design and theories? If so, where might I purchase a copy. I really have learned a lot from your posts.
Best Regards,
Rich
Thank you for the compliment, but you have me way over estimated. Really, I am nowhere near knowledgeable or experienced enough to consider such an endeavor.
Way more people around here are so far ahead of me on those terms. But glad that you been able to learn a few things or two.Cheers
Hi jReave,
Thanks for the detailed reply and alternative design ideas. I have considered another 3 way build. This one for my office/ exercise room. I'm fortunate that my wife allows me to build just about anything I want. But, she was not in love with my Avalon Isis inspired dual woofer 3 ways. So, she has asked me to build something else for the living room. That was music to my ears. Let the planning begin!
Best,
Rich
Thanks for the detailed reply and alternative design ideas. I have considered another 3 way build. This one for my office/ exercise room. I'm fortunate that my wife allows me to build just about anything I want.
But, she was not in love with my Avalon Isis inspired dual woofer 3 ways. So, she has asked me to build something else for the living room. That was music to my ears. Let the planning begin!Best,
Rich
Hi jReave,
Thanks once again for an outstanding suggestion. I think she likes a rather large tower but nothing to fancy with beveled edges or truncated pyramids. So, my thought was to use the drivers that I have already for a living room build. I have (4) Dayton RS225-8, (2) SB Acoustics 15MFC30-8, and (2) Dayton RS150P-8, (2) SS R2604/83300 tweets, and (2) Dayton RST28A tweets (the new generation just released). As you can see, I have some choices for consideration. Or, I may elected to buy that Satori mid you suggested. I have been eye balling that for quite some time now.
Anyway may apologies to JustinRT, I did not want to take over your thread.
Best Regards,
Rich
Thanks once again for an outstanding suggestion. I think she likes a rather large tower but nothing to fancy with beveled edges or truncated pyramids.
So, my thought was to use the drivers that I have already for a living room build. I have (4) Dayton RS225-8, (2) SB Acoustics 15MFC30-8, and (2) Dayton RS150P-8, (2) SS R2604/83300 tweets, and (2) Dayton RST28A tweets (the new generation just released). As you can see, I have some choices for consideration. Or, I may elected to buy that Satori mid you suggested. I have been eye balling that for quite some time now. Anyway may apologies to JustinRT, I did not want to take over your thread.
Best Regards,
Rich
Justin,
First some technical stuff:
- For home theater, you do want to be able to get loud for the occasional peaks. The THX standard is 105dB at the listening position, which I actually think is crazy loud
, like ear damaging loud for regular use, so I'd be satisfied, even more than satisfied with 100dB. Assuming headroom for 10dB peaks, that's an average listening level of 90dB at the listening position.
- Sound level drops off as you get further away from the source. In free space, you get about a 12dB drop from 1m to 4m. But.... in an enclosed space like a room, you tend to lose a little less, so I'd say about 9-10dB for your listening situation. So this means that you should be after a speaker capable of max SPL levels of about 110dB at 1m without exceeding the drivers' linear magnet/voice coil excursion limits (xmax). (Actually, you gain an extra 6dB when you double up the source, like with 2 speakers in stereo, but for HT, you want to count on each speaker, especially the CC, being able to reach those levels each on their own.)
- Now if you have a speaker with 90dB sensitivity with 1W at 1m, that means you'll hit your 110dB target with about 85W of power (SPL increases by 3dB every time you double the power). Looking at your AVR, you actually have 170W into 6ohm and 210W into 4ohm, meaning your present amps can hit your targets SPL's with at least 3dB of headroom left over if the speakers are 6ohm or lower. So I'd say that's your minimum sensitivity target.
So here's what I would probably put together given the above and (almost?) within your budget, it's a MTMW 3-way:
Woofer: 1 x Peerless 8" Nomex HDS 8ohm (which is really a 6ohm minimum) 90dB sensitivity, F3=~78Hz in 15L sealed, max SPL of 110dB with your AVR set to a 60Hz HP filter - $43 Cnd
Mids: 2 x Peerless 4" Glass Fiber HDS, 92dB sensitivity into 4ohm wired in parallel, max SPL of 109dB with 60W (I'm assuming that's ok given 30W RMS) with a 300Hz HP filter in about 6L - $26.5 Cnd each
Tweeter: SB 26STCN-4 92.5dB 4ohm - $33US. There a few to choose from here. I'd actually prefer a tweeter with a lower Fs but most of those are more expensive and I think this can get away with a 2500Hz xo LR4 without any problem. It won't quite mean MTM C2C spacing meets the rule of thumb, but I can live with it as an acceptable compromise.
Total cost per speaker Cnd is $96 x .78 exchange = $75 + $33 (for the tweeter)= $108 x 3 = $324 for L/C/R
Which leaves $176 for 3 x 3-way xo's which may or may not work out. I need to do a sim and see how many components are necessary.
Other options are still possible. I still like the MTM with the 5" SB on sale. Or I think one RS150-4 could work with the above woofer and tweeter in a TMW (but 2 of the 4" Peerless = more surface area than just one 5" Dayton) or maybe 2 x RS125T-8 could work instead of the Peerless mids, but I think those will be more expensive.
Let me know if you have any questions.
First some technical stuff:
- For home theater, you do want to be able to get loud for the occasional peaks. The THX standard is 105dB at the listening position, which I actually think is crazy loud
, like ear damaging loud for regular use, so I'd be satisfied, even more than satisfied with 100dB. Assuming headroom for 10dB peaks, that's an average listening level of 90dB at the listening position.- Sound level drops off as you get further away from the source. In free space, you get about a 12dB drop from 1m to 4m. But.... in an enclosed space like a room, you tend to lose a little less, so I'd say about 9-10dB for your listening situation. So this means that you should be after a speaker capable of max SPL levels of about 110dB at 1m without exceeding the drivers' linear magnet/voice coil excursion limits (xmax). (Actually, you gain an extra 6dB when you double up the source, like with 2 speakers in stereo, but for HT, you want to count on each speaker, especially the CC, being able to reach those levels each on their own.)
- Now if you have a speaker with 90dB sensitivity with 1W at 1m, that means you'll hit your 110dB target with about 85W of power (SPL increases by 3dB every time you double the power). Looking at your AVR, you actually have 170W into 6ohm and 210W into 4ohm, meaning your present amps can hit your targets SPL's with at least 3dB of headroom left over if the speakers are 6ohm or lower. So I'd say that's your minimum sensitivity target.
So here's what I would probably put together given the above and (almost?) within your budget, it's a MTMW 3-way:
Woofer: 1 x Peerless 8" Nomex HDS 8ohm (which is really a 6ohm minimum) 90dB sensitivity, F3=~78Hz in 15L sealed, max SPL of 110dB with your AVR set to a 60Hz HP filter - $43 Cnd
Mids: 2 x Peerless 4" Glass Fiber HDS, 92dB sensitivity into 4ohm wired in parallel, max SPL of 109dB with 60W (I'm assuming that's ok given 30W RMS) with a 300Hz HP filter in about 6L - $26.5 Cnd each
Tweeter: SB 26STCN-4 92.5dB 4ohm - $33US. There a few to choose from here. I'd actually prefer a tweeter with a lower Fs but most of those are more expensive and I think this can get away with a 2500Hz xo LR4 without any problem. It won't quite mean MTM C2C spacing meets the rule of thumb, but I can live with it as an acceptable compromise.
Total cost per speaker Cnd is $96 x .78 exchange = $75 + $33 (for the tweeter)= $108 x 3 = $324 for L/C/R
Which leaves $176 for 3 x 3-way xo's which may or may not work out. I need to do a sim and see how many components are necessary.
Other options are still possible. I still like the MTM with the 5" SB on sale. Or I think one RS150-4 could work with the above woofer and tweeter in a TMW (but 2 of the 4" Peerless = more surface area than just one 5" Dayton) or maybe 2 x RS125T-8 could work instead of the Peerless mids, but I think those will be more expensive.
Let me know if you have any questions.
If you already have some nice SBA drivers, I wouldn't purchase the Satori. It's like going from a Camry to an Avalon. At the end, it's not that big an improvement.
jReave,
That makes perfect sense regarding the CTC spacing of an MTM speaker. Thanks for setting me straight.
The reason that I'd like to use the compression tweeter with a waveguide is partially for the SPL, but mostly it's because, as I understand it, the waveguide give less vertical dispersion; which I think would help in my room, as it's going to be very far from ideal. The room is on the top floor, and has large dormers, so there are some funky angles in the ceiling. I've also just read anecdotally that the B&C/Denovo compression drivers sound nice, and work very well for HT speakers. But, I'm not dead set on anything specifically at this point, and I'm certainly not going to completely disregard the advice of people who clearly know much more than I. What would the drawbacks be if I used the compression tweeter and waveguide?
The way that I figured that I can toe-in the speakers is like this:
If this is a bad idea, I can flush mount them. The wall, however, might not allow me to avoid the baffle step loss; the right speaker is going to be close to a corner, and the left speaker is going to close to the edge of where the baffle wall ends.
I've drawn the room in Sketchup, so if it will help, I can make a post showing what the room will look like. (Fair warning, though: it is going to be a sonic nightmare, I think; but, it's the only space that I have available.)
I think that you've convinced me to go 3-way. If people here are willing to help me with the crossover design, then that assuages a lot of my reservations (have I mentioned how grateful I am to the people of this community?).
I've read up on REW a bit, as I plan to use it and a miniDSP to equalize my sub. I also plan to get a decent mic for this purpose, so I should be able to get some good measurements of my speakers, when the time comes. I'll definitely install the program soon and start familiarizing myself with it.
I'm not opposed to ordering from Solen, but it would probably have to be a pretty good deal, as shipping is pretty high (mitigated somewhat by the exchange rate). I'm also not sure if I'll have to pay duties... I'll look into it.
I just saw your post with the driver recommendations. Awesome! I don't time to look too close at them at the moment, but I should be able to later tonight.
No, please, by all means; I don't mind at all. Besides, I'm learning stuff when reading through your conversation.
That makes perfect sense regarding the CTC spacing of an MTM speaker. Thanks for setting me straight.
The reason that I'd like to use the compression tweeter with a waveguide is partially for the SPL, but mostly it's because, as I understand it, the waveguide give less vertical dispersion; which I think would help in my room, as it's going to be very far from ideal. The room is on the top floor, and has large dormers, so there are some funky angles in the ceiling. I've also just read anecdotally that the B&C/Denovo compression drivers sound nice, and work very well for HT speakers. But, I'm not dead set on anything specifically at this point, and I'm certainly not going to completely disregard the advice of people who clearly know much more than I. What would the drawbacks be if I used the compression tweeter and waveguide?
The way that I figured that I can toe-in the speakers is like this:
If this is a bad idea, I can flush mount them. The wall, however, might not allow me to avoid the baffle step loss; the right speaker is going to be close to a corner, and the left speaker is going to close to the edge of where the baffle wall ends.
I've drawn the room in Sketchup, so if it will help, I can make a post showing what the room will look like. (Fair warning, though: it is going to be a sonic nightmare, I think; but, it's the only space that I have available.)
I think that you've convinced me to go 3-way. If people here are willing to help me with the crossover design, then that assuages a lot of my reservations (have I mentioned how grateful I am to the people of this community?).
I've read up on REW a bit, as I plan to use it and a miniDSP to equalize my sub. I also plan to get a decent mic for this purpose, so I should be able to get some good measurements of my speakers, when the time comes. I'll definitely install the program soon and start familiarizing myself with it.
I'm not opposed to ordering from Solen, but it would probably have to be a pretty good deal, as shipping is pretty high (mitigated somewhat by the exchange rate). I'm also not sure if I'll have to pay duties... I'll look into it.
I just saw your post with the driver recommendations. Awesome! I don't time to look too close at them at the moment, but I should be able to later tonight.
No, please, by all means; I don't mind at all. Besides, I'm learning stuff when reading through your conversation.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.