My new speaker build
- Thread starter M Jarve
- Start date
MAXZ28
Addicted Member
Just think of it as a GI-NORMOUS cheddar cheese potato chip, Ron.
BOT: Excellent work MJarve & Bobfalk! :thmbsp:
'Wish you two were a little bit closer, I could you your talent on some CV grill frames about now. I need to get me a router. :scratch2:
M Jarve
Audio Geek and NGE Freak
Houston: We have Boxes!
Or almost. The cabinets are in a free-standing stage, meaning they are not just a pile of plywood any more. The front and rear baffles, as well as the sides had the finger-joint routing done today. The top and bottom pieces, as (as well as their mating edges on the baffles and sides) will be routed out when the cabinets are nearer completion.
We're currently waiting on a new router bit, apparently, to square up the cutouts on the table router, which Boy Wonder believes should arrive tomorrow.
Tonight I am seeing how much internal volume I want to sacrifice to bracing, as well as finalizing the driver layout. Perhaps some of the more knowledgeable among you can help me with that.
The sketch below shows the original plan for the speaker layout. The idea was to get the two woofers and the ports to try an act as a single larger driver. The set will be mirror imaged so that each has the tweeter on the inside edge, to deal with baffle diffraction. I know that narrow baffles are the norm to take care of this, but, I'm nothing if not abnormal.
My insane design (such as it is...) :
Front (left) and profile (right) :
Some parts :
Or almost. The cabinets are in a free-standing stage, meaning they are not just a pile of plywood any more. The front and rear baffles, as well as the sides had the finger-joint routing done today. The top and bottom pieces, as (as well as their mating edges on the baffles and sides) will be routed out when the cabinets are nearer completion.
We're currently waiting on a new router bit, apparently, to square up the cutouts on the table router, which Boy Wonder believes should arrive tomorrow.
Tonight I am seeing how much internal volume I want to sacrifice to bracing, as well as finalizing the driver layout. Perhaps some of the more knowledgeable among you can help me with that.
The sketch below shows the original plan for the speaker layout. The idea was to get the two woofers and the ports to try an act as a single larger driver. The set will be mirror imaged so that each has the tweeter on the inside edge, to deal with baffle diffraction. I know that narrow baffles are the norm to take care of this, but, I'm nothing if not abnormal.
My insane design (such as it is...) :
Front (left) and profile (right) :
Some parts :
Attachments
Are we looking at a tweeter and mid close together at the top and woofer bottom left with ports bottom right? If so, that should work ok. Depending on your crossover points you may want the woofer and mid closer together. Make sure you're <1/2 wavelength at crossover point for the center-to-center distance.
The set will be mirror imaged so that each has the tweeter on the inside edge, to deal with baffle diffraction. I know that narrow baffles are the norm to take care of this, but, I'm nothing if not abnormal.
Baffle diffraction has to do with sharp edges. Narrow baffles move the "baffle step" up to a point where it can be easily dealt with in the crossover. The way to deal with baffle diffraction is to smooth things out. Round the corners with as large a radius as you can. Barring that, chamfer the edges and that will help. Also, remove anything hard/sharp from the baffle and that will keep a lot of the diffraction (re-radiation of high frequency energy) from happening. You can also use felt or something similar to eat up the HF energy travelling along the baffle.
Ray
M Jarve
Audio Geek and NGE Freak
Thanks indeed. That was particularly what I wanted to know.
The system is a two-and-a-half way. Both the 6.5-inch drivers will be woofers, for all intents, though the one nearer the tweeter will have a higher cross-over point. As it stands, the lower woofer will be crossed over on the high-end at 250Hz, where as the higher woofer will be crossed over at ~2,500Hz. Do you see any issues with that?
Last edited:
M Jarve
Audio Geek and NGE Freak
A new ball game...
Well, there is a little bit of a monkey in the works now. You see, I happen to have a set of Insignia NS-2111 (better known as the Insignia coaxial) that are just begging to be installed in a better enclosure. I managed to find an impedance trace for them, and it looks like the Fs of the woofer is 35Hz. which would, I think, go over well in an enclosure tuned to 40Hz. It would also give an opportunity to hear how the driver would operate in an optimal enclosure.
So. I can either go with the original plan, which was a 2-1/2 way system, with the Radio Shack and Klipsch woofer with the RS neodyne soft-dome, or the new idea, which is a straight two-way with the Insignia driver... I hate having to make choices! :tears:
Well, there is a little bit of a monkey in the works now. You see, I happen to have a set of Insignia NS-2111 (better known as the Insignia coaxial) that are just begging to be installed in a better enclosure. I managed to find an impedance trace for them, and it looks like the Fs of the woofer is 35Hz. which would, I think, go over well in an enclosure tuned to 40Hz. It would also give an opportunity to hear how the driver would operate in an optimal enclosure.
So. I can either go with the original plan, which was a 2-1/2 way system, with the Radio Shack and Klipsch woofer with the RS neodyne soft-dome, or the new idea, which is a straight two-way with the Insignia driver... I hate having to make choices! :tears:
M Jarve
Audio Geek and NGE Freak
Gary, you're cruel! Actually, if all goes as planned, my next project will be my magnum opus...
bobfalk
"Boy wonder"
Did I hear someone volunteer?!?
M Jarve
Audio Geek and NGE Freak
Not fair! I was wired with two pots of coffee.
But, on another note, I have to come up with a solution to work around the weird 800Hz peak/1kHz dip of the Insignia driver. It looks like it can be fixed with a sort of notch filter in the crossover, or a slight alteration/tweak to the cone and suspension joint.
But, on another note, I have to come up with a solution to work around the weird 800Hz peak/1kHz dip of the Insignia driver. It looks like it can be fixed with a sort of notch filter in the crossover, or a slight alteration/tweak to the cone and suspension joint.
M Jarve
Audio Geek and NGE Freak
Okay- We're back on schedule (as if we ever had one...).
The Untitled Speaker Project has progressed to the stage where, if you don't know what you're doing, they are starting to resemble speakers. If, on the other hand you do know what you're doing, you'll recognize the mockery of sound reproduction Boy Wonder and I have committed.
Thing is, they sound pretty good, even at this stage. And I've not even begun to do the real tuning work yet.
Things that have yet to be done:
• Ports (installing and tuning of)
• Finalize crossovers and properly mount- the components are just tag-soldered to wire and scattered along the bottom
• Install bracing
• Back to Boy Wonder's for sanding, veneering, and finishing
• Install connection terminals
• Come up with a name
Here are some pictures to show that the Northern Elves have been busy.
A nearly completed speaker, actually playing music:
Same speaker, slightly different angle:
Completed speaker with the other (missing baffle):
Mirror imaged like real pro speakers and everything!
Hopefully the next set of pics will be the real, live finished product.
The Untitled Speaker Project has progressed to the stage where, if you don't know what you're doing, they are starting to resemble speakers. If, on the other hand you do know what you're doing, you'll recognize the mockery of sound reproduction Boy Wonder and I have committed.
Thing is, they sound pretty good, even at this stage. And I've not even begun to do the real tuning work yet.
Things that have yet to be done:
• Ports (installing and tuning of)
• Finalize crossovers and properly mount- the components are just tag-soldered to wire and scattered along the bottom
• Install bracing
• Back to Boy Wonder's for sanding, veneering, and finishing
• Install connection terminals
• Come up with a name
Here are some pictures to show that the Northern Elves have been busy.
A nearly completed speaker, actually playing music:
Same speaker, slightly different angle:
Completed speaker with the other (missing baffle):
Mirror imaged like real pro speakers and everything!
Hopefully the next set of pics will be the real, live finished product.
Attachments
M Jarve
Audio Geek and NGE Freak
I got the port holes drilled out and the ports cut today. I went with my original plan of installing two ports, but of smaller diameter. The inner diameter of each port is 2-inches, and the cabinet is tuned to 40Hz. The system exhibits very even bass response down to low E on my bass guitar and so should be satisfactory for almost all music, save some classical, organ, or electronic that does have content below ~40Hz.
I have not talked yet to Boy Wonder about this, but I am considering just screwing the front baffles in place, and not gluing it. The rope-caulk seals all internal corners, plus there will be some bracing installed. The rationale is that the speaker could be used with a different baffle/driver configuration in the future, and it could make servicing it easier, if it comes to it. Of course, I will forgo such a consideration if it seems to adversely affect the sound, but, I cannot see how it would at this point.
I listened to the one pictured below, and I think this should be a decent sounding set when finished. The sound is overall slightly cool of neutral (you must remember that I am conditioned to British tone), and they are fairly efficient. They will, I think, present a somewhat demanding load for a power amp, as the DCR is a low-ish 3.7Ω. Playing steady-state sinewaves from 20Hz up to 250Hz, the ports do not seem to exhibit any troublesome noise.
I intend to bring the other one to this stage hopefully by this evening to get a better idea of how a stereo set will perform.
A (more) nearly complete speaker- never mind the mess around the ports, as they're just rope-caulked in place for now.
I have not talked yet to Boy Wonder about this, but I am considering just screwing the front baffles in place, and not gluing it. The rope-caulk seals all internal corners, plus there will be some bracing installed. The rationale is that the speaker could be used with a different baffle/driver configuration in the future, and it could make servicing it easier, if it comes to it. Of course, I will forgo such a consideration if it seems to adversely affect the sound, but, I cannot see how it would at this point.
I listened to the one pictured below, and I think this should be a decent sounding set when finished. The sound is overall slightly cool of neutral (you must remember that I am conditioned to British tone), and they are fairly efficient. They will, I think, present a somewhat demanding load for a power amp, as the DCR is a low-ish 3.7Ω. Playing steady-state sinewaves from 20Hz up to 250Hz, the ports do not seem to exhibit any troublesome noise.
I intend to bring the other one to this stage hopefully by this evening to get a better idea of how a stereo set will perform.
A (more) nearly complete speaker- never mind the mess around the ports, as they're just rope-caulked in place for now.
