Um, getting something like Room EQ Wizard and an inexpensive microphone would accelerate this and make it all more accurate. It's totally worth the spend and effort.
Best,
Erik
Best,
Erik
I have REW and a Dayton calibrated mic. I replied to your earlier post above but the moderators having to approve my posts is apparently causing my replies to appear behind posts you already read from other people.
If you go back just a bit in the thread you can see me reply to you.
-Chris
Hmm, in a quick browse, didn't see any mention of using polar responses to find the best overall XO points; for sure you won't find them with WinISD as its usefulness has petered out by the driver's upper mass corner [Fhm = 2*Fs/effective Qts], unless of course this is where you plan to XO [not likely unless maybe a sub].
WRT baffle edge diffraction, this refers to its eigenmodes, so to 'soften' them, one needs to either heavily round over a panel's edges or add damping and/or taper it in ways that causes them to rapidly decay like one does with a room to deal with 'slap echo'.
One common way, especially on large baffles, is to offset the driver on the baffle at some golden or acoustic ratio to average them out, ideally in both planes, but at least horizontally for sure if not otherwise well damped. Note too that one ideally needs to consider any 'mirrored' boundaries such as the floor if the baffle is perpendicular to it, so not a bad plan to design some form of truncated pyramid shaped speaker or similar concept even if stand mounted.
GM
WRT baffle edge diffraction, this refers to its eigenmodes, so to 'soften' them, one needs to either heavily round over a panel's edges or add damping and/or taper it in ways that causes them to rapidly decay like one does with a room to deal with 'slap echo'.
One common way, especially on large baffles, is to offset the driver on the baffle at some golden or acoustic ratio to average them out, ideally in both planes, but at least horizontally for sure if not otherwise well damped. Note too that one ideally needs to consider any 'mirrored' boundaries such as the floor if the baffle is perpendicular to it, so not a bad plan to design some form of truncated pyramid shaped speaker or similar concept even if stand mounted.
GM
Did I say that, did I ? 😱
Sorry... I must have had it in my head you posted in another section.
Looks like you are getting some great advice anyhow.
Ok you've got it for bsc.
For baffle edge diffraction you could read this:
Diffraction from baffle edges
Tweeter diffraction
and simulate with this:
Home of the Edge
I would also suggest that beginning with a single full range driver can teach you many things like:
- box volume and vent design
- baffle step correction
- offsetting drivers in baffle to reduce diffraction
- use of measurment tools like mic and REW
- combine with simulation tools like Hornresp, Ajhorn, Akabak to model the whole speaker with edge effects, diffraction, baffle step, room reflections, baffle step correction.
And if you are adventurous - the modeling software gets you beyond the standard bass reflex boxes into transmission lines and such.
Single driver full range speakers also sound great and have natural phase coherence and point source behavior, no xo beam steering or lobing effects etc.
They are inexpensive and you can make boxes quickly with foam core and hot melt glue. Learn the basics with a $12 TC9FD or $27 RS100-4. They won't get you the dynamics or extension of a multiway speaker but are great for near field lower SPL's.
Look at the index of this thread and see just how many speakers you can build with a TC9FD and foam core. They all sound good too.
http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures.html
Understand how to make measurments with a calibrated mic and REW and use of gating to get near anechoic conditions.
Then jump into multiway and make measurements and design your XO. Start with a 2-way with high quality but relatively inexpensive drivers. Try to copy a proven design with your own XO and see what you get. By copying the base architecture and driver selection about 70% of the work is done because it means those drivers probably have a good simple XO that works.
Take Bagby's Continuum 2 way for example: AC130F1 woofer and RS28A-4 tweeter. Those are very well behaved drivers and you can probably come up with a 2nd order xo that works well. Better yet, buy the kit with XO parts and try designing your XO and see how close you come to one made by a master designer. Parts cost less as a kit and those tweeters are sold out if you try to hit individually anyhow.
Another great kit to buy with excellent quality drivers and Xo is the GR Research XLS Encore. High quality Peerless driver and Vifa tweeter with a superb prebuilt XO and all parts like wires screws ports binding posts form a pair of speakers for $170. Really an unbeatable deal. Try to design that XO having it in hand as a guide. You learn a lot faster by following a master designers' footsteps than making your own trail into uncharted territory.
http://gr-research.com/x-lsencorekit.aspx
Good luck.
In addition to Xsim, Bagby's PCD is also excellent.
- box volume and vent design
- baffle step correction
- offsetting drivers in baffle to reduce diffraction
- use of measurment tools like mic and REW
- combine with simulation tools like Hornresp, Ajhorn, Akabak to model the whole speaker with edge effects, diffraction, baffle step, room reflections, baffle step correction.
And if you are adventurous - the modeling software gets you beyond the standard bass reflex boxes into transmission lines and such.
Single driver full range speakers also sound great and have natural phase coherence and point source behavior, no xo beam steering or lobing effects etc.
They are inexpensive and you can make boxes quickly with foam core and hot melt glue. Learn the basics with a $12 TC9FD or $27 RS100-4. They won't get you the dynamics or extension of a multiway speaker but are great for near field lower SPL's.
Look at the index of this thread and see just how many speakers you can build with a TC9FD and foam core. They all sound good too.
http://www.diyaudio.com/forums/full-range/223313-foam-core-board-speaker-enclosures.html
Understand how to make measurments with a calibrated mic and REW and use of gating to get near anechoic conditions.
Then jump into multiway and make measurements and design your XO. Start with a 2-way with high quality but relatively inexpensive drivers. Try to copy a proven design with your own XO and see what you get. By copying the base architecture and driver selection about 70% of the work is done because it means those drivers probably have a good simple XO that works.
Take Bagby's Continuum 2 way for example: AC130F1 woofer and RS28A-4 tweeter. Those are very well behaved drivers and you can probably come up with a 2nd order xo that works well. Better yet, buy the kit with XO parts and try designing your XO and see how close you come to one made by a master designer. Parts cost less as a kit and those tweeters are sold out if you try to hit individually anyhow.
Another great kit to buy with excellent quality drivers and Xo is the GR Research XLS Encore. High quality Peerless driver and Vifa tweeter with a superb prebuilt XO and all parts like wires screws ports binding posts form a pair of speakers for $170. Really an unbeatable deal. Try to design that XO having it in hand as a guide. You learn a lot faster by following a master designers' footsteps than making your own trail into uncharted territory.
http://gr-research.com/x-lsencorekit.aspx
Good luck.
In addition to Xsim, Bagby's PCD is also excellent.
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Have a look at The Speaker Building Bible.
It's got a number of dead links now but most everything from "Speaker Designing with Software" and down should be very useful to you. Some of Bagby's tools are especially recommended as long as you have Excel and if have, see also here which should replace the dead link to the FRD Consortium in the Bible.
So for example, since you are trying to understand baffle diffraction right now, the Edge is a great tool for oddly shaped cabinets but it fails to include edge treatment effects. For that, you can try either Bagby's or the Consortium's diffraction simulators which again will handle different cabinet, edge and/or driver conditions. Bagby's software has the benefit of also including boundary re-enforcement effects too if you want to look at those. And once you get a handle on that, move on the Response Modeler which allows you to combine the FR of a driver with your cabinet diffraction (among other things) to see exactly what the combination is going to look like.
And when you are ready to move forward with measurements, here is the white paper you want to follow: How to Achieve Accurate In-Room Quasi-Anechoic Free-Field Frequency Response Measurements Down to 10 Hz
My philosophy is that as you start using better and better drivers, you should also be building deader and quieter cabinets, so you should perhaps direct your attention to that area as well. Just be warned that there are a number of differing schools of thought on that subject.
It's got a number of dead links now but most everything from "Speaker Designing with Software" and down should be very useful to you. Some of Bagby's tools are especially recommended as long as you have Excel and if have, see also here which should replace the dead link to the FRD Consortium in the Bible.
So for example, since you are trying to understand baffle diffraction right now, the Edge is a great tool for oddly shaped cabinets but it fails to include edge treatment effects. For that, you can try either Bagby's or the Consortium's diffraction simulators which again will handle different cabinet, edge and/or driver conditions. Bagby's software has the benefit of also including boundary re-enforcement effects too if you want to look at those. And once you get a handle on that, move on the Response Modeler which allows you to combine the FR of a driver with your cabinet diffraction (among other things) to see exactly what the combination is going to look like.
And when you are ready to move forward with measurements, here is the white paper you want to follow: How to Achieve Accurate In-Room Quasi-Anechoic Free-Field Frequency Response Measurements Down to 10 Hz
My philosophy is that as you start using better and better drivers, you should also be building deader and quieter cabinets, so you should perhaps direct your attention to that area as well. Just be warned that there are a number of differing schools of thought on that subject.
I noticed it yesterday but didn't see a reason to say anything.
Thank you for the welcome.
-Chris
Thanks for the additional links. I read through it and get now how it starts at frequencies dependent on the width of the baffle.
-Chris
I know this is silly but I read this and thought, no highs, no lows, must be Bose.
Before I started this thread I had been reading some threads around here and saw the recommendations to start with a two way build. Honestly, at that time I was thinking I don't want a stupid two way speaker, I'm going 3 way. And my goal is still a nice 3 way active build. But I'm coming around a bit on building a 2 way bookshelf kinda speaker to get started. Maybe even with passive crossovers.
I'm not quite sure what I would do with them though. I've got a 15 year old pair of B&W DM303 bookshelfs with matching center channel that I still like just fine.
I just don't know about the full range thing though. I see the value for learning but would I actually ever want to just listen to a full range? What's a realistic frequency range from a good full range driver in a well done enclosure?
Thanks,
Chris
Thank you for the links.
I'm pretty much a MDF guy with lots of bracing when it comes to enclosures but I have seen good plywood recommended as a better material.
When I built the baffle for the four 15" subs in my IB, I doubled up on 3/4" MDF so the walls were 1.5" thick. Even after cutting big holes on four of the five sides I was barely able to get the thing up the attic ladder.
-Chris
You're welcome!
Some folks add foam, you name it, absorbent material along the edges or at least a strip between the driver
Horn with foam 'baffle' insert and just attached to it:
100_4020.jpg Photo by Russ058 | Photobucket
http://www.av-iq.com/avcat/IMAGES/products/enlarge/CH™ 642QT.jpg
Lots of options depending on how you want the speaker to perform in the allotted space.
GM
In room, with a standard ceiling height? At least 20-20 kHz with a decent quality ~6.5" and some 8" in a simple BIB [bigger is better] pipe horn:
http://www.diyaudio.com/forums/full...anyone-have-those-fostex-craft-handbooks.html
https://speakerprojects.wordpress.com/cabinet-types/bib-loudspeakers/bib-calculator/
http://www.quarter-wave.com/General/Fostex_FE-167E_BIB_Design.pdf
GM
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Holy 10 year running 500 page thread! I read the cliff notes in the PDF you linked.
I'm assuming Greg Montfort = GM. So did Terry Cain know this enclosure would perform so well before he created the first one or was he trying out different stuff and stumbled upon it?
You guys are pretty damn impressive.
I'm having thoughts now of a plate amp and bluetooth receiver mounted on the back of a pair of these things. Heck I can't hear over 16K anyway.
-Chris
Close: Greg Monfort [no extra 't']
No, not exactly as he built them on 'faith'/curiosity after a PM discussion we had based on my experience with simple corner loaded pipe bass horns after he'd read my response to a thread about 1/2 WL TLs [which technically don't exist] on the late, lamented 'full-range' forum that unfortunately was completely lost AFAIK. A pity, in some aspects it had more anecdotal knowledge than DIYaudio's, i.e. more amateur local club like since it wasn't ad driven.
GM
No, not exactly as he built them on 'faith'/curiosity after a PM discussion we had based on my experience with simple corner loaded pipe bass horns after he'd read my response to a thread about 1/2 WL TLs [which technically don't exist] on the late, lamented 'full-range' forum that unfortunately was completely lost AFAIK. A pity, in some aspects it had more anecdotal knowledge than DIYaudio's, i.e. more amateur local club like since it wasn't ad driven.
GM
My stuff is certainly not like any Bose with no lows or highs. In fact, take for example, a $12 Vifa TC9FD full range driver in a well designed DCR enclosure covers 50Hz to 20kHz with decent distortion figures at reasonable SPL levels for a near field speaker.
http://www.diyaudio.com/forums/full-range/252627-viva-la-vifa-curvy-cabinet-dcr-tc9fd.html
Here is the clean impulse response:
You can listen to it for yourself and get a sense of the highs and lows - sound clips recorded with a Zoom H4:
http://www.diyaudio.com/forums/atta...binet-dcr-tc9fd-dcr-vifa-clip-real-bsc-06.zip
Or the same TC9FD driver in a ML-TQWT with a Karlson aperture (0.40x scale Karslonator):
http://www.diyaudio.com/forums/full-range/239338-mini-karlsonator-0-53x-dual-tc9fds.html
It covers 70Hz to 18kHz with no BSC needed.
Listen to what a single 3.5in driver can sound like here:
http://www.diyaudio.com/forums/atta...0-53x-dual-tc9fds-04x-karlsonator-clip-01.zip
What do you guys think about this plan? First build the Scanspeak Discovery based 3-way that system7 linked, exactly as designed except active. I already know I like the sound of that 10F mid since I have them in my car.
Once I get the active setup dialed in I can decide what I might want to upgrade or try to improve with the higher end Scanspeak drivers I'm wanting to try out. Or maybe just start by adding a second identical 8" driver in a larger cabinet since my room and listening position makes bass pretty tough.
ScanSpeak-3W-Discovery
Thanks,
Chris
Once I get the active setup dialed in I can decide what I might want to upgrade or try to improve with the higher end Scanspeak drivers I'm wanting to try out. Or maybe just start by adding a second identical 8" driver in a larger cabinet since my room and listening position makes bass pretty tough.
ScanSpeak-3W-Discovery
Thanks,
Chris
The 3 way Discovery in active would be a fine way to go. I was considering the same thing myself and save the $700 in XO parts from TG/Jantzen. Plus, with active, you could even use a XO topology to make it quasi transient perfect. In that case, go with a sealed woofer and use Linkwitz transform for bass. Two 8in woofers would be nice and make it a floor stander.
iScream, did you try listening to the last sound clip linked at the bottom of the previous post #38? Let me know what you think of the sound of a 3.5in $12 full range driver.
iScream, did you try listening to the last sound clip linked at the bottom of the previous post #38? Let me know what you think of the sound of a 3.5in $12 full range driver.
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