I got two Alpair 10p full-range drivers and plugged them into the woofer holes of old speaker boxes I took apart. I took the old tweeters out and left a big hole in the box. I also took out the bass port tubes and plugged up the back hole. So now the tweeter hole in the front is like a bass port? I thought these couldn't possibly sound good like this and put them in storage for a while. I just pulled them out and plugged them into an old Denon receiver and was pleasantly surprised by the sound. How is it possible this sounds half-decent?
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LOL...
I guess you could take the measurements of the speaker box and plug it into an online calculator.
Then for a 'ported design' add in the radius/diameter of the port. (Tweeter hole)
It should then come up w a length of the tube for the port.
Because of the size of the hole, I'd expect the tube length to be short.
But I suspect 'half way decent is subjective. ;-)
I guess you could take the measurements of the speaker box and plug it into an online calculator.
Then for a 'ported design' add in the radius/diameter of the port. (Tweeter hole)
It should then come up w a length of the tube for the port.
Because of the size of the hole, I'd expect the tube length to be short.
But I suspect 'half way decent is subjective. ;-)
In many speakers, successful crossovers need to account for acoustic slopes (and other things) affected by the enclosure and driver parameters. But in a full-range design, obviously crossovers don't exist - so it is easier to sound half decent through the more critical ranges (even if still sub-optimal). Most of the potential issues with a full-range enclosure mismatch will likely be in the lower frequencies.
The other factor is that 'half-decent' sound isn't especially difficult anyway, if one is lucky enough for the driver and enclosure to be a vaguely suitable pairing. It generally just requires nothing too awful to happen. Turning that into 'fully decent' is mostly what a lot of the time, effort and expertise is spent on.
The other factor is that 'half-decent' sound isn't especially difficult anyway, if one is lucky enough for the driver and enclosure to be a vaguely suitable pairing. It generally just requires nothing too awful to happen. Turning that into 'fully decent' is mostly what a lot of the time, effort and expertise is spent on.
https://www.diyaudioandvideo.com/Guide/BuildSpeaker/
This is the link to the main site that has some of the calculators.
I'm no expert but you can also plug in the values for the driver and it would suggest a cabinet volume.
I'm sure there are others who are better sources of advice.
I think its cool that you did this.
I also think we're entering another 'golden age' in hi fi, in that w D class amps and the ability to get plans, and sometimes the CNC files... one can go out and make decent sounding speakers. Companies like CSS have built a niche of kits to showcase their drivers.
Plenty of YouTube videos showing how to make speakers.
This is the link to the main site that has some of the calculators.
I'm no expert but you can also plug in the values for the driver and it would suggest a cabinet volume.
I'm sure there are others who are better sources of advice.
I think its cool that you did this.
I also think we're entering another 'golden age' in hi fi, in that w D class amps and the ability to get plans, and sometimes the CNC files... one can go out and make decent sounding speakers. Companies like CSS have built a niche of kits to showcase their drivers.
Plenty of YouTube videos showing how to make speakers.
A vintage/classic Japanese speaker called Diatone P-610 used such a cab; very shallow rectangular duct more like a hole with a bit of inside lip. Reputed to sound like a cross between BR and OB (and I more or less confirm). I actually have two made-in-China renditions one ~2009 alnico and a more recent ferrite -- both designed by Gong Xiaoming but "opposite" frequency response. The latter design was the basis of his company, Correct; in many ways I "approve" of the name. The earlier alnico Orgue P-610 Signature has the sweetest, most refined mids I've ever heard, but too little hi/lo (Japanese taste?). The ferrite has as much bass playing nude as the Orgue 25L BR-cross-OB (and quite decent bass in its own similar cab). Indeed I run them stacked, dubbed "alcor66". Violin up/down bow strokes and other nuances are obvious through them.
Sometimes crude speakers can sound good; I recently purchase some mid/bass drivers without the TS perimeters, so I stuck them in some boxes to see how they sound, I boosted the treble with a cheap graphic equalizer to account for the lack of tweeters, and they sound, erm, surprisingly good.
Let’s figure the volume out a little closer.
But given Jeff’s guess, a 2” plumbing pipe, 4.6” long. But it could be better if you decrease the box volume. Toss some “bricks" inside.
If you sealed it close to as big as practical for sealed, starts rolling off early, but drops slowly. F3 at about 100 Hz, F10 in the low 40s.
About 17 litres is optimum.
dave
But given Jeff’s guess, a 2” plumbing pipe, 4.6” long. But it could be better if you decrease the box volume. Toss some “bricks" inside.
If you sealed it close to as big as practical for sealed, starts rolling off early, but drops slowly. F3 at about 100 Hz, F10 in the low 40s.
About 17 litres is optimum.
dave