PASC, sou do Rio de Janeiro e estou pensando em montar esse projeto com 18 sound .Vc poderia me dar mais detalhes na montagem das caixas ?
Do you think this type of cone make up would be optimal for this design also?
Might the removal of the S1 angle piece benefit this cab like we think it may for the 6 Fold?
Might the removal of the S1 angle piece benefit this cab like we think it may for the 6 Fold?
Crescendo
Look at posts 524 and 528 in this thread.
The sneaky bit is that the Vee shape for the cone can be used to increase the path length of the speaker, as it coincides with the position of an existing fold in the SS15 / TH18 folding geometry.
As for if the reduction in volume at S1 has any significance in these TH designs, try varying the S1 volume up and down in Hornresp.
The net result is a smoother HF response with less S1 and slightly more LF with a bigger S1 (More volume utilised in the speaker).
So far no one seems to have any practical interest at all in the smoother HF response that I was trying to acheive. The smoothed out response seems to be above the passband of what most people are using the speaker for.😀
The dificulty (in my mind) is to fully implement and publish these mods as a TH18 Mk2 speaker would be to post a Danley copy cab (as confirmed by Art Welter in post 528)😱
Regards Xoc 1 (Martin)
Look at posts 524 and 528 in this thread.
The sneaky bit is that the Vee shape for the cone can be used to increase the path length of the speaker, as it coincides with the position of an existing fold in the SS15 / TH18 folding geometry.
As for if the reduction in volume at S1 has any significance in these TH designs, try varying the S1 volume up and down in Hornresp.
The net result is a smoother HF response with less S1 and slightly more LF with a bigger S1 (More volume utilised in the speaker).
So far no one seems to have any practical interest at all in the smoother HF response that I was trying to acheive. The smoothed out response seems to be above the passband of what most people are using the speaker for.😀
The dificulty (in my mind) is to fully implement and publish these mods as a TH18 Mk2 speaker would be to post a Danley copy cab (as confirmed by Art Welter in post 528)😱
Regards Xoc 1 (Martin)
Many PA horn designs (not just TH's) can benefit from cone volume correction if it is not compensated during the design stage. Often such shortcoming can be noticed when the measurement of the actual build is not in line with its prediction.
Note: 1w/1m or 2.83V/1m show smaller differences with the predictions as high power measurements.
Generally speaking, the smaller the ratio between the volume in the first section of any horn and the volume of the cone plus its baffle cut out, the more effect a cone correction can have.
The only thing you need to know is the volume of the cone. Even that is piece of cake. Fill your driver with dried peas, softairgun balls, micro balls or whatever you have around. Than use a measuring cup to see how much volume your cone (+ baffle cut out) is. The result is the volume your cone correction needs to be. It does not matter very much how it looks (for subrange that is) as long it is positioned in the right place.
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If you have a large sized driver compared to the last section of the horn, compensating or correcting the volume occupied by the driver can be an improvement.
I thought the point of the exercise was to accurately replicate the model; wouldn't that create a deviation from the the design? 😉
If the model you're referring to is the HornResp model, it has already been replicated by a few members here. The driver I'm using has a drop off at a slightly higher frequency in this design (38.5Hz vs 36.5Hz), so if I can retrieve the couple Hz lost without degrading the rest of the frequency response, I will (for my uses).
Dan has a point there, Justin. To make it play lower and keep the smooth response you'll need too extend the path length (some 12 to 15cm or so) 🙂.
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You're saying removing reflectors 1, 2 & 4 will shorten the path length? According to SG3525's response curve he recorded and posted (link above), his response lowered by removing these 3.
??????
- I think he simply agreed that doing so would deviate from the model.
- We know you want MOAR BASS!!! So he also suggested a longer path for additional LF extension.
I dunno what the deal is on this thing but it looks like a hunk of star trek themed aluminum bolted to a thin looking (stamped?) backplate, maybe they are going into car audio...
HEY I think I see what's going on here now that I type this...
It's a floating pole piece DDD motor like the JBL drivers.
HEY I think I see what's going on here now that I type this...
It's a floating pole piece DDD motor like the JBL drivers.
Are there any uploads of the TH-18 angled cuts? I'm making sawdust right now and can't find any saved on my computer... 🙂
Yes Martin posted them in one of his files. I used them when
Making mine. They worked out perfectly I used plain Titebond wood glue on the angled cuts and there were no gaps. No need for PL urethane glue!
Making mine. They worked out perfectly I used plain Titebond wood glue on the angled cuts and there were no gaps. No need for PL urethane glue!