my own experience with Open Baffles and rear vented BLH horns is enough to suggest that the two alcoves flanking the fire place would be less than ideal
something like a Linkwitz LX mini / Pluto and sub might be worth considering?
LXmini construction
something like a Linkwitz LX mini / Pluto and sub might be worth considering?
LXmini construction
I just realized they are back-loaded. No, that's not what I meant...
Well, from what I gather, open-baffle really should be away from any walls, is that right? Or are there exceptions to that rule?
That's certainly my understanding, which for a full range OB or dipole / panel
wouldn't appear to be practical if you revert to the original layout
wouldn't appear to be practical if you revert to the original layout
OK, so I think for now I have to forget about open-baffle.
If I should want to stick with a full-range, possibly supported by a subwoofer, would it make sense to make a very large cabinet that sort of fills the entire space next to the fireplace? With the driver in-line with the fireplace mantel?
If I should want to stick with a full-range, possibly supported by a subwoofer, would it make sense to make a very large cabinet that sort of fills the entire space next to the fireplace? With the driver in-line with the fireplace mantel?
If you're talking full range in the sense of single wide band driver per side, something like what is referred to here as a FAST system ( think 2 way with lower than normal XO) could make sense. Depending on your choice for the mid/tweeter driver, XO to the woofers would likely still be high enough ( anywhere from 200-330 or so has been my own experience with over half a dozen such systems over the past few years) that such woofers would need to be collocated, although it's not absolutely essential they share the same enclosure.
This also means that to cover the entire range from as low below 40Hz as you want to attain, and with which the room will cooperate 😉 may still require separate sub(s) - of which I still recommend multiples of for distributed bass in rooms with proven issues such as seems to your case.
With the exception of the Ellipses, almost all of the FR/FAST systems I've built have had small enough footprints to not require the full floor space of those alcoves, which certainly comes in handy for optimizing location and toe-in. They've also with only two exceptions been bi-amped with passive line level XO, simply because that method is so damned cheap, and I've just not yet sprung for a tolerable active XO or minidsp type of arrangement
This also means that to cover the entire range from as low below 40Hz as you want to attain, and with which the room will cooperate 😉 may still require separate sub(s) - of which I still recommend multiples of for distributed bass in rooms with proven issues such as seems to your case.
With the exception of the Ellipses, almost all of the FR/FAST systems I've built have had small enough footprints to not require the full floor space of those alcoves, which certainly comes in handy for optimizing location and toe-in. They've also with only two exceptions been bi-amped with passive line level XO, simply because that method is so damned cheap, and I've just not yet sprung for a tolerable active XO or minidsp type of arrangement
That all sounds pretty promising. I will just not experience that open-baffle sound though, but I can always mount the full-range speaker I choose temporarily on a board just to get an idea...
I have been thinking about bi-amping, and using an Ashly XR-1001 as an active crossover. I like the idea of having a bit of control over the sound after everything is built.
But you think a FAST design with, let's say, a 15" woofer, would not be able to go down low enough?
Oh, there's little doubt a pair of 15s in appropriate box design could go low enough to eliminate the need for subs in a hospitable room, the real question is how well they might blend with a smaller wide-band driver in a FAST, and fit the available placement location.
Of the several FASTs I've built, the largest FR driver has been an Alpair7P, most of them have been Fostex FF85K & WK, and I've used multiples of mid-bass drivers as small as the Peerless 830860. That one is not a homewrecker system, but very compact and when bi-amped, more capable than you'd think possible. However, I've yet to hear a wide-band driver based system that couldn't benefit from "subs(s)" well matched to the room, and am a big fan of multiple woofers for distributed bass, particularly in less that perfect rooms - which describes every one I've ever used.
Of the several FASTs I've built, the largest FR driver has been an Alpair7P, most of them have been Fostex FF85K & WK, and I've used multiples of mid-bass drivers as small as the Peerless 830860. That one is not a homewrecker system, but very compact and when bi-amped, more capable than you'd think possible. However, I've yet to hear a wide-band driver based system that couldn't benefit from "subs(s)" well matched to the room, and am a big fan of multiple woofers for distributed bass, particularly in less that perfect rooms - which describes every one I've ever used.
I am thinking something similar to this, but with a full-range on top instead of a 3-way:
OB's need big distance from rear and side wall, so if you've got a problem already ...it seems you are going to get more problems.
To do:
Big heavy curtains in front of the windows, a thick decorative carpet on the sidewall behind the sofa, a 6 foot high recycled bookshelf filled with books ( often you can get loads of books, cheap or even for free = you don't care what they contains, their new life is for dampening purpose ) and i guess you're hitting the goal. Do the clap test when the stuff is added ..it's not that hard to deal with.
Let's work
Yes. I decided that, for the speaker placement in my room, an open-baffle is out of the question.
Definitely curtains, and maybe a hanging diffuser, as mentioned earlier, behind the sofa. Need to make it visually pleasing though. There is not much space for a bookshelf though... there is a bunch of little stuff in front of the bay windows.To do:
Big heavy curtains in front of the windows, a thick decorative carpet on the sidewall behind the sofa, a 6 foot high recycled bookshelf filled with books ( often you can get loads of books, cheap or even for free = you don't care what they contains, their new life is for dampening purpose ) and i guess you're hitting the goal. Do the clap test when the stuff is added ..it's not that hard to deal with.
Let's work
What about the ceiling?
The Aplair 7P is what is on the top of my list. I would like to pair that with a large woofer, crossed at 300 Hz or lower. Then bi-amp this, with the Ashly XR-1001. Well, that's the idea at least... need to figure out the cabinet design now.chrisb said:
What I am trying to figure out is:
1) front (baffle) width
2) woofer position on baffle (I believe side-mounted won't work for my room)
3) FR speaker position on baffle
4) closed or front-vented bass reflex
5) which woofer
Maybe I should start a separate thread for this... unless you tell me, that my current idea is complete BS 🙂
Nothing wrong with that most recent line of thinking.😀
Designs I've built have generally had the FR and mid-bass drivers mounted with acoustic centres as close as possible: either by means of wide panel MTM - rather tight spacing with A7P, less so with FF85WK- others with skinny box and side mounted woofers. After a couple of disappointing results a few years back - both sonically and WAF-wise, I've not done anything serious with OBs- even for the FR portion - just not my cuppa tea.
Depending on the chosen woofers, either sealed or rear vented would fine, and from my experience with all generations of the Alpair7 - both metals and paper- I'd suggest vented for them. They may model nicely enough sealed, but I just prefer them in either an MLTL or back loaded horn.
Designs I've built have generally had the FR and mid-bass drivers mounted with acoustic centres as close as possible: either by means of wide panel MTM - rather tight spacing with A7P, less so with FF85WK- others with skinny box and side mounted woofers. After a couple of disappointing results a few years back - both sonically and WAF-wise, I've not done anything serious with OBs- even for the FR portion - just not my cuppa tea.
Depending on the chosen woofers, either sealed or rear vented would fine, and from my experience with all generations of the Alpair7 - both metals and paper- I'd suggest vented for them. They may model nicely enough sealed, but I just prefer them in either an MLTL or back loaded horn.
Your sofa is too close to the back wall for a diffuser.
I'd follow wesayso's suggestion with a big panel made for absorption instead. Even a thick or heavy carpet hanging on the wall would be a better idea.
Places like Home Hardware have nice patterns to choose from and look pretty good.
Thanks, that will make it actually easier, too. I did hang up a large 7' x 7' blanket some days ago, and it really helped a lot.
But if you do woofer and FR in the same box, shouldn't they have separate chambers? And then vent the FR, but not the woofer (if I decide on a woofer that's normally not vented)?chrisb said:Nothing wrong with that most recent line of thinking.
Designs I've built have generally had the FR and mid-bass drivers mounted with acoustic centres as close as possible: either by means of wide panel MTM - rather tight spacing with A7P, less so with FF85WK- others with skinny box and side mounted woofers. After a couple of disappointing results a few years back - both sonically and WAF-wise, I've not done anything serious with OBs- even for the FR portion - just not my cuppa tea.
Depending on the chosen woofers, either sealed or rear vented would fine, and from my experience with all generations of the Alpair7 - both metals and paper- I'd suggest vented for them. They may model nicely enough sealed, but I just prefer them in either an MLTL or back loaded horn.
I am a bit confused...
Also, I have seen some designs where the woofer was placed very close to the bottom. It's supposed to take advantage of floor reflections... whether that works out well or not, I have no idea.
Yes, if it wasn't clear that the FR and woofers should be in separate enclosures - which was definitely the case in all my builds alluded too - the confusion is understandable. Some of the woofers I've used ( i.e. CSS SDX7) definitely work best sealed, while others - Silver Flute W14, Peerless 830870, Alpair 12PW can probably go either way, but I tend to like them vented - which often means larger volumes required, but the enclosures are still generally well within reasonable sizes - certainly as compared to the total footprint and "breathing room " required for OB or large dipole & panel systems .
No doubt there's math and logic behind either approach - I've found the closer proximity of drivers with XO's in the region of the lowest hundreds ( 200-330 ) seems integrate more seamlessly
But you did say you didn't like any of these arrangements, or did I get this wrong? I am really not sure what I should try... I definitely want a 2-way, bi-amped with an active crossover, as I like the flexibility, and after reading a bit on the ESP website it really seems to make sense.
Well, so due to my room I ruled out OB. Now I am wondering, does an FR with a 12 or 15 inch woofer crossed at 200-300 make sense, or should I maybe look into a completely different style, like a Beyma TPL-150 with a mid-woofer?
It's a hard decision; I wish I could just go out and listen to a bunch of designs, but I wouldn't know where to go... and also, a different room can completely change the sound of any speaker I like again. So I want to jump into the cold water and just try something that people seem to be happy with...
Yah, it was probably not hard to misconstrue my vague comments, so I'll try to make myself clearer - keeping in mind that this is all based on subjective personal experience, and there are lots of approaches : there is no single "right" way - just a reasonable compromise that works for a particular set of needs / room.
I've heard a range of OB systems both at my own home, DIY get-togethers and hi-fi shows. The only system that I particularly enjoyed the sound of was a Lowther & Tone-Tubby woofer combination driven by ungodly expensive and esoteric tubed electronics, and playing in a hotel conference room of at least 800ft^2. Like driving a Bugatti Veyron, I might imagine - a nice benchmark of performance that I could never afford in my real life, so neatly filed away in the memory banks under "yup, that was cool, but.."
To a lesser degree I've had the same experience with large dipole ESL and magneto-planar systems from Quad ESL57 (singles and stacked pairs), Acoustats, Martin Logans, Dayton Wright, Magnepans, etc. - can be wonderful in systems rooms that I can never afford. .
Over my past dozen or so years of DIY speaker building I've had the most fun in what many would describe as the kiddie pool - lower powered systems, mostly now based around "Full" (really only Wide-band) drivers, assisted with woofers/subs - both monopoles and push-push bipoles.
Depending on exactly where in the bandwidth the XO to bottom end occurs, some systems of this configuration have recently come to wear the badge of "FAST"s - an acronym I personally don't care for, but which seems to have some currency.
There is currently an ongoing thread on the subject of "which component has the most impact" - for me, there’s no contest - it's the degree of synergy between speaker/room . Absent the ability to completely dedicate a “perfect” room to the purpose, and implement all the treatment necessary, I've had to adopt the design philosophy of "make the speaker fit the room" - meaning not just aesthetically, but acoustically. That of course often means varying degrees of compromise from lofty goals of absolute performance - depending on the room.
Back to how I might deal with this case. If placement flanking the window and firing down the long dimension of the room isn't practical, I'd consider trying to move the couch a short distance from the back wall (even a foot can help) and adding some shallow diffraction products such as home-made quadratic diffusers, backed or flanked with mid-band absorption treatment. There are abundant sources of such information on the web.
Effective treatment for deep bass problems take more physical space than you may have, and I think for the most part would have very low WAF for a shared family space. Distributed bass consisting of several (at least 2) small subs that are not collocated with the mains on either side of the fireplace could go a long way to evening things out. With such subs rolled in at, say 80-100Hz, much of the heavy lifting is relieved from the mains, and a small FAST system, with either passive XO or active & bi-amped could suffice. As I am obviously a fan of FR drivers, I could happily recommend something like an Alpair 7.3 (metal) or the 7P (paper), and any of a range of 6-8" mid-woofers of modest price - TangBand, SilverFlute, Peerless, SEAS - there's an embarrassment of riches from which to choose these days, and all brands will have their staunch advocates.
The past few years' great advances of affordable DSP for XO / Room Correction / EQ, and silly cheap class D amplification make fully active speaker systems more attractive, flexible and affordable than ever. Just keep the amps out of all speaker boxes - not in the least the subs.
As this is a DIY forum, it’d be easy to get lots of advice on what to replace your speakers with, but you already have considerable time and treasure invested in your current speakers, and they may yet serve you well - adapting some of the above methods could save you much grief and expense.
Pull the speakers forward enough to be past the alcove of fireplace, experiment with toe-in, try some thick absorption behind the speakers ( a couple of batts of 3” fiberglass insulation) , move the couch forward, High pass the mains around the commonly used range of sub crossovers and see if your mid bass recovers over a wide range of listening locations. Then it’s time to think about dealing with the bottom couple of octaves, and to repeat myself, I think distributed smaller subs (8-10”) is the way to go.
I've heard a range of OB systems both at my own home, DIY get-togethers and hi-fi shows. The only system that I particularly enjoyed the sound of was a Lowther & Tone-Tubby woofer combination driven by ungodly expensive and esoteric tubed electronics, and playing in a hotel conference room of at least 800ft^2. Like driving a Bugatti Veyron, I might imagine - a nice benchmark of performance that I could never afford in my real life, so neatly filed away in the memory banks under "yup, that was cool, but.."
To a lesser degree I've had the same experience with large dipole ESL and magneto-planar systems from Quad ESL57 (singles and stacked pairs), Acoustats, Martin Logans, Dayton Wright, Magnepans, etc. - can be wonderful in systems rooms that I can never afford. .
Over my past dozen or so years of DIY speaker building I've had the most fun in what many would describe as the kiddie pool - lower powered systems, mostly now based around "Full" (really only Wide-band) drivers, assisted with woofers/subs - both monopoles and push-push bipoles.
Depending on exactly where in the bandwidth the XO to bottom end occurs, some systems of this configuration have recently come to wear the badge of "FAST"s - an acronym I personally don't care for, but which seems to have some currency.
There is currently an ongoing thread on the subject of "which component has the most impact" - for me, there’s no contest - it's the degree of synergy between speaker/room . Absent the ability to completely dedicate a “perfect” room to the purpose, and implement all the treatment necessary, I've had to adopt the design philosophy of "make the speaker fit the room" - meaning not just aesthetically, but acoustically. That of course often means varying degrees of compromise from lofty goals of absolute performance - depending on the room.
Back to how I might deal with this case. If placement flanking the window and firing down the long dimension of the room isn't practical, I'd consider trying to move the couch a short distance from the back wall (even a foot can help) and adding some shallow diffraction products such as home-made quadratic diffusers, backed or flanked with mid-band absorption treatment. There are abundant sources of such information on the web.
Effective treatment for deep bass problems take more physical space than you may have, and I think for the most part would have very low WAF for a shared family space. Distributed bass consisting of several (at least 2) small subs that are not collocated with the mains on either side of the fireplace could go a long way to evening things out. With such subs rolled in at, say 80-100Hz, much of the heavy lifting is relieved from the mains, and a small FAST system, with either passive XO or active & bi-amped could suffice. As I am obviously a fan of FR drivers, I could happily recommend something like an Alpair 7.3 (metal) or the 7P (paper), and any of a range of 6-8" mid-woofers of modest price - TangBand, SilverFlute, Peerless, SEAS - there's an embarrassment of riches from which to choose these days, and all brands will have their staunch advocates.
The past few years' great advances of affordable DSP for XO / Room Correction / EQ, and silly cheap class D amplification make fully active speaker systems more attractive, flexible and affordable than ever. Just keep the amps out of all speaker boxes - not in the least the subs.
As this is a DIY forum, it’d be easy to get lots of advice on what to replace your speakers with, but you already have considerable time and treasure invested in your current speakers, and they may yet serve you well - adapting some of the above methods could save you much grief and expense.
Pull the speakers forward enough to be past the alcove of fireplace, experiment with toe-in, try some thick absorption behind the speakers ( a couple of batts of 3” fiberglass insulation) , move the couch forward, High pass the mains around the commonly used range of sub crossovers and see if your mid bass recovers over a wide range of listening locations. Then it’s time to think about dealing with the bottom couple of octaves, and to repeat myself, I think distributed smaller subs (8-10”) is the way to go.
Thank you for your detailed answer. It all made a lot of sense, and I agree with you in many points, especially with the fact that a speaker really needs to be tailored for the room, I have experienced that myself a few times.
It already came to my mind, that I might just want to try to make the best out of what I have for now. I will definitely do some more experiments with room treatments and my listening position. I happen to have an extra roll of "Ultratouch" insulation, so that might be a good place to start. As I still haven't done the window trim, I can also design that with acoustics in mind...
The setup with the bass-guitar amp as a subwoofer was definitely an improvement, so I think that I will make that one investment now, for an Ashly XR-1001, to use it as an active crossover with the main speakers. I can always use the crossover later when I feel ready to build a pair of speakers.
The thing is, I just have build my own pair of speakers eventually. It is just like I really want to know what an MC cartridge would sound like, after I have only run MM cartridges for many years. In the same way I really want to know what a full-range speaker with a sub would sound like, or even a studio-monitor speaker setup with a ribbon tweeter or so.
I checked our library, and they have at least one good book on acoustics, called "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms". I will read into that. And also keep reading here and elsewhere on the 'net. Once I am feel more confident about what I am talking about, I will come back here with more questions 🙂
I'll let you know how the Ashly works out.
It already came to my mind, that I might just want to try to make the best out of what I have for now. I will definitely do some more experiments with room treatments and my listening position. I happen to have an extra roll of "Ultratouch" insulation, so that might be a good place to start. As I still haven't done the window trim, I can also design that with acoustics in mind...
The setup with the bass-guitar amp as a subwoofer was definitely an improvement, so I think that I will make that one investment now, for an Ashly XR-1001, to use it as an active crossover with the main speakers. I can always use the crossover later when I feel ready to build a pair of speakers.
The thing is, I just have build my own pair of speakers eventually. It is just like I really want to know what an MC cartridge would sound like, after I have only run MM cartridges for many years. In the same way I really want to know what a full-range speaker with a sub would sound like, or even a studio-monitor speaker setup with a ribbon tweeter or so.
I checked our library, and they have at least one good book on acoustics, called "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms". I will read into that. And also keep reading here and elsewhere on the 'net. Once I am feel more confident about what I am talking about, I will come back here with more questions 🙂
I'll let you know how the Ashly works out.
First Measurements
Finally an update to this post... I hope someone is still following it, and willing to help.
For the moment I have abandoned the idea to build new speakers, and instead focus on what some of you told me to do here: Get REW and a USB Mic and measure your room, try to improve room acoustics.
So, I got REW installed and familiarized myself with it, and also got a miniDSP UMIK-1 microphone. At the same time, I installed a few curtains along the windows, and started to build some bass traps (not done yet).
I also found a great EQ, a vintage Technics SH-8065 with 33 bands per channel. I did want to stay in the "analog domain", although I did find the miniDSP solution quite tempting...
I used three ways to measure and eq:
- Pink Noise 20-20kHz played from the "Test Equalization Record", REW's RTA module open and set to 1/3 octave (like the EQ itself), adjusting in real-time
- The same as above, but Pink Noise played through the laptop from REW
- The "normal" measurement method in REW, adjusting after each measurement (which are the final results you see below).
Here are the measurements, followed by a few questions:
I don't have an RTA screenshot, but it looked pretty smooth, with a bit of trouble around 300 Hz.
Questions:
1) How should I position the Mic? I understand it should be where my head is, in listening position. But should I point it straight between the speakers? Or point it at each speaker for each L/R measurement, and centered for L+R?
2) The graphs show the eq'd responses, and I notice that the combined response shows some valleys that did not exist in either left or right measurement, why is that? Do frequencies somehow cancel each other out?
3) How can I figure out through measurement, where and how to place the bass traps?
4) That dip around 100 Hz, is that a "null" or a room mode or something? Not too sure how to interpret this yet... the EQ is definitely not way down at 100 Hz...
Oh, and I almost forgot to mention: It definitely sounds a lot better with the EQ! Quite a difference...
Thanks for any pointers!
Finally an update to this post... I hope someone is still following it, and willing to help.
For the moment I have abandoned the idea to build new speakers, and instead focus on what some of you told me to do here: Get REW and a USB Mic and measure your room, try to improve room acoustics.
So, I got REW installed and familiarized myself with it, and also got a miniDSP UMIK-1 microphone. At the same time, I installed a few curtains along the windows, and started to build some bass traps (not done yet).
I also found a great EQ, a vintage Technics SH-8065 with 33 bands per channel. I did want to stay in the "analog domain", although I did find the miniDSP solution quite tempting...
I used three ways to measure and eq:
- Pink Noise 20-20kHz played from the "Test Equalization Record", REW's RTA module open and set to 1/3 octave (like the EQ itself), adjusting in real-time
- The same as above, but Pink Noise played through the laptop from REW
- The "normal" measurement method in REW, adjusting after each measurement (which are the final results you see below).
Here are the measurements, followed by a few questions:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I don't have an RTA screenshot, but it looked pretty smooth, with a bit of trouble around 300 Hz.
Questions:
1) How should I position the Mic? I understand it should be where my head is, in listening position. But should I point it straight between the speakers? Or point it at each speaker for each L/R measurement, and centered for L+R?
2) The graphs show the eq'd responses, and I notice that the combined response shows some valleys that did not exist in either left or right measurement, why is that? Do frequencies somehow cancel each other out?
3) How can I figure out through measurement, where and how to place the bass traps?
4) That dip around 100 Hz, is that a "null" or a room mode or something? Not too sure how to interpret this yet... the EQ is definitely not way down at 100 Hz...
Oh, and I almost forgot to mention: It definitely sounds a lot better with the EQ! Quite a difference...
Thanks for any pointers!
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What source are you using? Since you are using a laptop for testing I strongly suggest trying room correction instead of plain EQ. Have a look at this thread for more info:
http://www.diyaudio.com/forums/full...ectrical-loudspeaker-correction-networks.html
http://www.diyaudio.com/forums/full...ectrical-loudspeaker-correction-networks.html
While I'm definitely a fan of room correction and DSP in general it might be a bit much in this case. Plus the OP has told us he wants to remain Analog for now.
I'd suggest first you start learning to "read" what you measure. The left and right curve don't look that bad (after EQ). The reason it does not add up when playing left and right together can be any number of things. First I'd suggest looking at the "Impulse" tab in REW. Zoom in on the first ~ 20ms on that tab and look at what that tells you. Look at the left, Right and both together.
For instance, if the measurement microphone wasn't at the exact same distance from the left and right speaker it will not add up like you would expect it to. But the "Impulse" tab should show 2 distinct separate pulses. Easy to say for me, but rather hard to get sometimes in the real world as one would need a clean pulse (to start with) from the speaker to see it. But the IR plot (on the "Impulse" tab) can tell us a number of things. So for starters I'd like to see what that first ~ 20 ms looks like.
For the microphone position, I'd suggest in the listening spot, aimed straight forward between both speakers for now. Aimed at tweeter height with the microphone at ear level on the listening spot. Is it a calibrated microphone?
I'd suggest first you start learning to "read" what you measure. The left and right curve don't look that bad (after EQ). The reason it does not add up when playing left and right together can be any number of things. First I'd suggest looking at the "Impulse" tab in REW. Zoom in on the first ~ 20ms on that tab and look at what that tells you. Look at the left, Right and both together.
For instance, if the measurement microphone wasn't at the exact same distance from the left and right speaker it will not add up like you would expect it to. But the "Impulse" tab should show 2 distinct separate pulses. Easy to say for me, but rather hard to get sometimes in the real world as one would need a clean pulse (to start with) from the speaker to see it. But the IR plot (on the "Impulse" tab) can tell us a number of things. So for starters I'd like to see what that first ~ 20 ms looks like.
For the microphone position, I'd suggest in the listening spot, aimed straight forward between both speakers for now. Aimed at tweeter height with the microphone at ear level on the listening spot. Is it a calibrated microphone?
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