I am going to start with 480 because it is smaller and I want to work out kinks. 290 will take some serious lumber, and i want to make sure it is the route I want to go. 480 will give me good idea of sound while working out woofer box/s. Ill finish one horn this week and then spend weekend getting measurement gear up and running. Its gonna be a long process, i think, but i want to get drivers measured before winter sets in.
GM,
Been looking at old Altec enclosure materials and saw a couple of options I would like your opinion on.
VOT Corner loaded home cabinet
210
9844
817
The 9844 has very similar Vas to what I modeled in unibox, shoeing about 3 cubic feet per 414. All these could work, but I dont know what to expect fomr the horn loaded versions. The tall 210 could be flipped and the hornincluded in the oen cavity. May be too tall for my listening enviroment.
Been looking at old Altec enclosure materials and saw a couple of options I would like your opinion on.
VOT Corner loaded home cabinet
210
9844
817
The 9844 has very similar Vas to what I modeled in unibox, shoeing about 3 cubic feet per 414. All these could work, but I dont know what to expect fomr the horn loaded versions. The tall 210 could be flipped and the hornincluded in the oen cavity. May be too tall for my listening enviroment.
I dont really understand TL, TBO. I always thought it was about line length and how the quarterwave reinforced the low end. I dont understand how a big *** box is a TL, but you know i dont know s^%$. Martin's sheets are not exactly clear to the uneducated mass(me), but I have gotten decent results. 10 cubic ft box for single 414 isn't real doable, as I do believe that dual's will sound better. I am somewhat limited on size, for both room reasons and wife reasons. I was quite surprised to see that she was ok with side by side, but after looking at it, it does fit the room nicely. Altec 817 is verticaclly stacked horn. I could grill cloth the front and it would look fine.
In using Martin's MLTL worksheets with dual woofers, one has to imagine an acoustic center for the combination, the center between the pair on the baffle. This is used to enter the combined electrical parameters for the driver pair and the various distances to other aspects of the chamber that affect the response.
Due to the fact that the source is not a point on the baffle but distributed between drivers, the port response will be a broader peak than if from a "point source"...there is some similarity here with how Lynn has been speaking about "resistive vents" over in his thread...though it is (internally) source related, not directly an aspect of the port.
Due to the fact that the source is not a point on the baffle but distributed between drivers, the port response will be a broader peak than if from a "point source"...there is some similarity here with how Lynn has been speaking about "resistive vents" over in his thread...though it is (internally) source related, not directly an aspect of the port.
Found this after refinding this site a day ago. Been looking for it for ages. Some nice builds
Project | Homebuilt Hi-Fi Horn & twin 15's Maybe a bit too monolithic?
Project | Homebuilt Hi-Fi Horn & twin 15's Maybe a bit too monolithic?
Looks pretty good, doesnt it. I may go that route, but want to look into side by side 12's or single 15, as I have the drivers. Gluing up boards to do the horn right now. I like your choice of the HF144. If I went with Faital, that was the driver I was going to try. THer waveguides are pretty inexpensive as well and have probably been designed specifically for their drivers, so may be a good combination until you decide on bigger final horn. Did you see pics of the 288's? Things are enormous. Weight 37lbs each.
Fro what I have read,I agree. I am trying to devise a TL cabinet for a single 414, Get it worked out and ten just make another and mate the two together, side by side, with 290 horn on top. JBL LE15A seems a little easier to work with and will be my first attempt at single 15 under 480 horn. I would think taking these roads would give me a pretty good feel for both ALtec sound as well as big vintage 15" woofer sound. Managing to put them in TL of some sort will let me hear big driver in that arrangement for first time, liking what i have heard from smaller FR units.
That exactly what I was thinking with the 144.
The 288's are whoppers. You'll have to make a big old support for them!! I nearly had a pair with 311-90 horns from a cruise ship refurb but gave up bidding at £700
the horns weighed in at 29lb a piece too.Its funny that delicate high frequencies demand SO much weight
Are you going to minidsp this lot until your settled on a setup? Its probably cheaper than the parts if you make a change or 3. Then make up the passive crossover when you are happy
Before considering MTM, please read/absorb/'wrap your mind around' what's in this article first: Biro Technology
Did you account for the increase in Qts the Pass amp's output impedance will cause? If not, you may get that 'flabby' bass you can't tolerate without mucho vent damping.
For best overall performance, woofer choices depend on the HF horn's directivity and XO point/slope.
GM