Check this image in Zaph's description. You can see the effect of differing dcr's on your coil.
http://www.zaphaudio.com/BAMTM-modeled-L2DCRoptions.gif
Hello!
I'm new to the whole DIY scene but i've grown partial to this setup and I plan on building these speakers over the next month or so. I'll probably be coming here for help but first of all i'm also very new to the whole crossover thing.
If anyone has any images of this specific crossover it might help me visualized the schematic and so I can build it easier.
Any links for a newbie with crossovers in general would be of great help as well. Thanks!
-MissionSix
I'm new to the whole DIY scene but i've grown partial to this setup and I plan on building these speakers over the next month or so. I'll probably be coming here for help but first of all i'm also very new to the whole crossover thing.
If anyone has any images of this specific crossover it might help me visualized the schematic and so I can build it easier.
Any links for a newbie with crossovers in general would be of great help as well. Thanks!
-MissionSix
Zaph Project
Thanks to Zaph for another great project. I am an alumnus of the college in his hometown and greatly appreciate his sharing his talents. I am building the bargain aluminum MTM as a project with my son. Since we live in different states, we have planned to build the speakers the week of January 15th. Unfortunately, the Dayton DA175 drivers are on backorder and may not be available when we get together. I thought we would proceed and build the cabinets, install the crossover, etc, and finish whenever the drivers are shipped.
Could someone tell me the diameter and depth I should route the inset for the Dayton drivers? I was told the actual cutout should be 5 and 5/8th inches. Thanks very much and happy holidays to all.
Thanks to Zaph for another great project. I am an alumnus of the college in his hometown and greatly appreciate his sharing his talents. I am building the bargain aluminum MTM as a project with my son. Since we live in different states, we have planned to build the speakers the week of January 15th. Unfortunately, the Dayton DA175 drivers are on backorder and may not be available when we get together. I thought we would proceed and build the cabinets, install the crossover, etc, and finish whenever the drivers are shipped.
Could someone tell me the diameter and depth I should route the inset for the Dayton drivers? I was told the actual cutout should be 5 and 5/8th inches. Thanks very much and happy holidays to all.
Re: Zaph Project
I'll take a quick moment to address some questions here.
These are solid 4 ohm nominal speakers, and are probably not a good idea for an 8 ohm receiver. That said, many will work fine anyway until they trigger thermal protection. I'm currently using them with a Panasonic digital receiver rated for 6 ohm speakers, but it will easily run 3 ohm speakers hard all day. It just depends on the quality of the receiver.
Your easiest solution is to just lay the components out on a board in the arrangement they are shown on the schematic. With a crossover this simple, that's generally easy to do.
All drivers are countersunk in this system.
The outside diameter is 175 mm and needs to be 3.5 mm deep. Note that it's 175mm minimum. Any smaller and it won't fit. you could go a mm or two larger without it looking like too big of a gap though. Likewise, you could go a mm deeper with the countersink. There is a foam gasket on the back side of the flange, and how tight you make the screws will vary how far the frame goes in.
I'll take a quick moment to address some questions here.
jaygeorge1979 said:
These are solid 4 ohm nominal speakers, and are probably not a good idea for an 8 ohm receiver. That said, many will work fine anyway until they trigger thermal protection. I'm currently using them with a Panasonic digital receiver rated for 6 ohm speakers, but it will easily run 3 ohm speakers hard all day. It just depends on the quality of the receiver.
missionsix said:
Your easiest solution is to just lay the components out on a board in the arrangement they are shown on the schematic. With a crossover this simple, that's generally easy to do.
UNDERSTANDIN said:
All drivers are countersunk in this system.
toward said:
The outside diameter is 175 mm and needs to be 3.5 mm deep. Note that it's 175mm minimum. Any smaller and it won't fit. you could go a mm or two larger without it looking like too big of a gap though. Likewise, you could go a mm deeper with the countersink. There is a foam gasket on the back side of the flange, and how tight you make the screws will vary how far the frame goes in.
Bump.
Do I get it right..? The ZD5 has a symmetrical vertical polar response, as seen in this picture:
http://zaphaudio.com/ZD5-modeled-polar-1400-blue-3400-red-200step.gif
The ladder delay network seems to give all the benefits of an MTM design, except for the doubled-up bass driver and its increased sensitivity & dynamics. Or am I missing something?
Oh, I do have one more question. John recommends an 80Hz LR4 subwoofer x-over. Does this mean the acoustic LR4 response? If you put a 4th order high pass @ 80Hz with the driver rolling off -3dB @ 60Hz in a sealed box, I'd imagine the response is a little off.
With a TL design (which I'm waiting to see..!) that's a whole different story though.
Do I get it right..? The ZD5 has a symmetrical vertical polar response, as seen in this picture:
http://zaphaudio.com/ZD5-modeled-polar-1400-blue-3400-red-200step.gif
The ladder delay network seems to give all the benefits of an MTM design, except for the doubled-up bass driver and its increased sensitivity & dynamics. Or am I missing something?
Oh, I do have one more question. John recommends an 80Hz LR4 subwoofer x-over. Does this mean the acoustic LR4 response? If you put a 4th order high pass @ 80Hz with the driver rolling off -3dB @ 60Hz in a sealed box, I'd imagine the response is a little off.
With a TL design (which I'm waiting to see..!) that's a whole different story though.
Hi guys,
This thread is discussing the BAMTM project.
http://www.zaphaudio.com/BAMTM.html
The last two posts appear to be in reference to the ZD5. There's another thread for that somewhere, maybe we can get the moderator to move the posts.
This thread is discussing the BAMTM project.
http://www.zaphaudio.com/BAMTM.html
The last two posts appear to be in reference to the ZD5. There's another thread for that somewhere, maybe we can get the moderator to move the posts.
moving woofers closer together
<NOOB>
I'm building 3 of the BAMTMs as my first non-subwoofer DIY project, and had read where Zaph said they wouldn't be suitable for use as a CC beause of lobing issues.
I notice that the woofers are quite far apart.
would moving them closer together (even to the point of having to displace the tweeter frather to the side, or perhaps trimming the tweeter surround and overlapping the woofers where the tweeter flange would have been) reduce the lobing issues?
would this completely screw up the speaker or reequire a complete redesign of the x-over?
</NOOB>
<NOOB>
I'm building 3 of the BAMTMs as my first non-subwoofer DIY project, and had read where Zaph said they wouldn't be suitable for use as a CC beause of lobing issues.
I notice that the woofers are quite far apart.
would moving them closer together (even to the point of having to displace the tweeter frather to the side, or perhaps trimming the tweeter surround and overlapping the woofers where the tweeter flange would have been) reduce the lobing issues?
would this completely screw up the speaker or reequire a complete redesign of the x-over?
</NOOB>
Zaph said:
Sorry, it was very early in the morning. What i meant to ask was: have you [Zaph] given thought to make a BAMTM construction with woofer elements with similar quality to the Seas L18, eg the L12?
Given that theoretically, a d'appolito configuration has a better dispersion pattern that a normal two way configuration, this could possibly give better results than the L18/27TBFCG construction?
Sorry if this belongs in a different thread..
To Gonar...
Yes, significantly changing the tweeter/woofer spacing would change things enough to require a crossover redesign.
Generally the vertical lobing (now become horizontal, when laying it down) of a MTM is too much to make a good center channel.
Of course, if it's just you and a significant other, and you like to sit close on the couch for movies... and your sitting position is dead center, and you don't plan on having several seats wide in the future...
Check Zaph's dispersion graphs, and visualize the vertical pattern as shooting across your room. If those nulls remain far away, it might not be too bad. Of course, when you invite 6 friends over for a movie, some will end up with "bad seats".
Really, the best would be a dedicated (and non MTM) center.. might look for a MT with the DA175, there are a few out there...
Yes, significantly changing the tweeter/woofer spacing would change things enough to require a crossover redesign.
Generally the vertical lobing (now become horizontal, when laying it down) of a MTM is too much to make a good center channel.
Of course, if it's just you and a significant other, and you like to sit close on the couch for movies... and your sitting position is dead center, and you don't plan on having several seats wide in the future...
Check Zaph's dispersion graphs, and visualize the vertical pattern as shooting across your room. If those nulls remain far away, it might not be too bad. Of course, when you invite 6 friends over for a movie, some will end up with "bad seats".
Really, the best would be a dedicated (and non MTM) center.. might look for a MT with the DA175, there are a few out there...
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