Jim,
There are several ways to expand the throat area: custom draw the channels to have a wider throat if you want to keep external dimensions the same; increase depth of channel, or grow whole cabinet. Note that some compression is ok, if ratio of throat area to Sd is greater than 75%, it's probably ok. For low Qts, high Bl drivers with low xmax, you might want more compression to load driver and reduce excursion. It should be modeled - a simple model in HornResp with a conical horn for first section to exponential horn near mouth wirh
appropriate dimensions for driver chamber will tell you a lot about excursion of cone.
If you are using the plan from planet10's pdf diagram, I think the the throat width is 0.9 in for the 27.6 in cornu. That is 2.3 cm wide not 17 mm wide. This gives a throat area of about 57 cm^2 for a 5 in deep channel. This about a perfect match for your driver if you wanted no compression. You could probably go as thin as 4 in and be ok.
What are the T/S params for your Altec driver?
Good luck!
Xrk971
Hey Cal- I was just looking at your speaker projects. What on earth do you do with all that marvelous stuff? 😀
Unless you and the others gives us a first name, that's a secret.
I have further listened to to the LG's and I don't know what to say. My wife is in the bath and she asks [honest to Jimmy], are those the new ones?
3" speakers doing that? 😀
I have further listened to to the LG's and I don't know what to say. My wife is in the bath and she asks [honest to Jimmy], are those the new ones?
3" speakers doing that? 😀
Post 340 tells you what I know. I wish I had more of them, seriously.
What I can say is they sound really nice, they are better than expected.
Jimmy appreciates that. 😉
What I can say is they sound really nice, they are better than expected.
Jimmy appreciates that. 😉
Cal,
I missed that post somehow. Glad they sound good, do you have any photos? Are these one of those concave aluminum dome drivers? Who is Jimmy? Buffett?
I missed that post somehow. Glad they sound good, do you have any photos? Are these one of those concave aluminum dome drivers? Who is Jimmy? Buffett?
Prezden'
Very nice setup there! 😀
Is that the Sure TPA3110 amp you are using? How do you like it?
Very nice setup there! 😀
Is that the Sure TPA3110 amp you are using? How do you like it?
Nice work. Did you notice something something pretty significant? The resulting horns closely follow an exponential length/area law. You can model single-spiral (divided 4 ways) Cornu horns in Hornresp using a single exponential section, and the multi-length horns like the one in your post in AkAbak. I'll modify (simplify) my AkAbak model accordingly.
Hello. Has anybody tried this with a different enclosure shape? Aesthetically I was thinking about a circular overall shape rather than square. Good idea? Many thanks for any advice.
I posted a fibonacci pentagon concept (5 equal horns), i tcould easily become a circle. It needs detailing.
dave
Don,
I have re-spun the cornu generator to make a reasonably sized horn than I can build: 24 in x 3.5 in deep, driver chamber cross sectional area of 148 cm^2, chamber volume of 1312 cm^2, channel lengths of 147 cm and 104 cm long, the throat cross sectional area (both) is 31.3 cm^2 - which will provide a mild level of compression for the TC9FD Sd of 36.4 cm^2. The horn mouth area is 2168 cm^2 I am still doing the bifurcation. See attached plan. I did a simplistic sim in HR for each horn independently and then combined them after the fact to see if the bumps and valleys help cancel out. I still plan to to use the TC9FD with this. I am still unclear how to specify the channel width as function of distance in Akabak for the true cornu. Thanks for trying this in Akabak.
Regards,
Xrk971
Attachments
Thanks Xrk971!
All I know about the Altec 405A is what I found on the Altec site--which is nearly useless. And I haven't the tools to measure the T/S parameters. Which is why I want to try a quick, inexpensive, flexible design.
Cheers, Jim
It is a modified TPA3110. I haven't tried it in any other configuration but I sure like it with these little guys. 🙂
Short of pulling them out this seems to be the only pic I have of them. They were originally used as tweeters in the 'Toolbox' as it is similar to a FAST system.
Don't let my wife see this pic or I'm in trouble. I tell her I always cover the table.
Attachments
Cal,
Is it those little silver ones? I didn't even know LG makes speakers. I mean I guess no reason why not they are huge like Sony. Has your BIL started yet?
Is it those little silver ones? I didn't even know LG makes speakers. I mean I guess no reason why not they are huge like Sony. Has your BIL started yet?
Yes they are the white coloured ones. I have been listening for the last two hours and I am still in disbelief.
BIL has not been sent anything until I am happy.
Cheers
BIL has not been sent anything until I am happy.
Cheers