The resonance of a line is a function of both length and taper, not just length. Taking the selected tuning frequency (usually the Fs of the driver) and dividing that wavelength by 4 only works for straight lines. A positive taper line (which expands toward the terminus) needs to be substantially longer than a straight one for the same tuning freqency, while a negative taper line (narrowing toward the terminus) will be substantially shorter than a straight line for the same tuning frequency. The line / pipe / whatever you wish to call it also needs to have sufficinet volume or you'll loose gain. Martin King discusses this in one of his papers: http://www.quarter-wave.com/Theory/Alignment_Tables.pdf
Installing the driver at the very end of a TL will excite all the harmonics and cause a great deal of ripple on the FR.
ron
ron
Hi,
carbord tubes, I also have a bunch ready in various diameters...even a 38cm/15" tube. They always come in very handy...🙂
I still think a real wooden enclosure will make a big difference. also wonder if your TL should have the driver in the end (like it is) or somewhere at 70% of the TL length....I'm no TL expert you see, but most designs have this and building plans are most specific about these dimensions....
I think your TL might lack a bit of low end from the enormous bafflestep. Adding a baffle or placing the driver near a surface will have a similar effect....
You may want to tweak the filter after the driver is placed in another enclosure...
carbord tubes, I also have a bunch ready in various diameters...even a 38cm/15" tube. They always come in very handy...🙂
I still think a real wooden enclosure will make a big difference. also wonder if your TL should have the driver in the end (like it is) or somewhere at 70% of the TL length....I'm no TL expert you see, but most designs have this and building plans are most specific about these dimensions....
I think your TL might lack a bit of low end from the enormous bafflestep. Adding a baffle or placing the driver near a surface will have a similar effect....
You may want to tweak the filter after the driver is placed in another enclosure...
I meant to write 'cardboard' there, and I somehow didn't notice your posts, Ronc and Scottmoose...
You guys described the problems of this design already. Though we have to understand drEM just used it for testing. I still think it would be better to leave the final tweaking of the filter for when the driver is in decent accommodation...😉
You guys described the problems of this design already. Though we have to understand drEM just used it for testing. I still think it would be better to leave the final tweaking of the filter for when the driver is in decent accommodation...😉
Actually had this a while now just neglected to post. This is my SPH-30X installed in a wooden box.
Its larger than the initial value WinISD generates (0.9L), I made it 1.7L and tuned it down to 94Hz or so. It gives a less flat response but gets it down to 100Hz a bit easier (probably increases excursion a bit too as a downside).
Box is made from quite large timbers hollowed out with a jigsaw. The port is an integral part of the structure drilled out with a bench drill. Front and back are plywood.
Using it with my filters it sounds quite decent. I often use it when I just want to watch YouTube videos, or quietly at night. A setereo pair would be nice to hear but doubt I'll actually implement it.
Bass is naturally quite light, EQ doesn't really work because it'll run out of excursion too quickly. Covers most the bass guitar range reasonably well though and is fairly "suprising" considering it's size. Voices are very realistic though can be a bit forward.
Should cut those timbers flat top and bottom really but anyhow 🙂
Its larger than the initial value WinISD generates (0.9L), I made it 1.7L and tuned it down to 94Hz or so. It gives a less flat response but gets it down to 100Hz a bit easier (probably increases excursion a bit too as a downside).
Box is made from quite large timbers hollowed out with a jigsaw. The port is an integral part of the structure drilled out with a bench drill. Front and back are plywood.
Using it with my filters it sounds quite decent. I often use it when I just want to watch YouTube videos, or quietly at night. A setereo pair would be nice to hear but doubt I'll actually implement it.
Bass is naturally quite light, EQ doesn't really work because it'll run out of excursion too quickly. Covers most the bass guitar range reasonably well though and is fairly "suprising" considering it's size. Voices are very realistic though can be a bit forward.
Should cut those timbers flat top and bottom really but anyhow 🙂
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Hey, that looks attractive! 🙂
I still haven't taken the time to finetune Geoff's filter design. But for the moment I am very happy with my initial filter.
I have found these chokes:http://nl.farnell.com/jsp/search/productdetail.jsp?sku=1193630
They are very compact and light. It makes a major difference in harshness of voices to use the filter. The potmeter functions as an extensive midrange control. The enclosure I use is 1 liter with two drivers inside (which are very near eachother), maybe that's why it rocks so good....
I still haven't taken the time to finetune Geoff's filter design. But for the moment I am very happy with my initial filter.
I have found these chokes:http://nl.farnell.com/jsp/search/productdetail.jsp?sku=1193630
They are very compact and light. It makes a major difference in harshness of voices to use the filter. The potmeter functions as an extensive midrange control. The enclosure I use is 1 liter with two drivers inside (which are very near eachother), maybe that's why it rocks so good....
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Has anyone measured this monacor driver slightly off-axis so far (like 15 to 30 deg) ?
Regards
Charles
Regards
Charles
Those monacor drivers look good...
Would they work well in nearfield studio monitors?
I already have a sub, and intend to cross it over at 100-150Hz, and it looks like it would work well with a pair of monacor's.
The only thing that seems bad is the peak around 10k... perhaps crossing it over at 7.5k might fix this?
Would they work well in nearfield studio monitors?
I already have a sub, and intend to cross it over at 100-150Hz, and it looks like it would work well with a pair of monacor's.
The only thing that seems bad is the peak around 10k... perhaps crossing it over at 7.5k might fix this?
MikeHunt79 said:
It has been done:
http://www.lautsprechershop.de/hifi/index.htm?/hifi/ct224.htm
Cal Weldon said:
You have got a point there Cal....
Ooo, nice! Thanks for the link. 🙂 I'm gonna build a portable system first, then move on to some monitors... So many projects, so little time! 
Ahh yes, exellent thread. It's great to see so many different sorts of boomboxes. 🙂 I'm looking into horn loading this driver, but I'm not sure iif it will work as well as the tang band 3" or 4"...v-bro said:
After looking into it, it's going to be more trouble than it's worth for either... I'm going to go for a normal ported box... Speaking of which....v-bro said:
How did you get the driver to work with WinISD?Dr.EM said:
I tried inputting all the TS parameters, and got the following error (see attached)... 🙁
Could you post up yer wdr file or somethng... 😉
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since were talking about 3" er's
If you had to pick from FE103E and the SPH 30x which is the better bang for the buck?
I'll pay probably within $20-30 of each other to get a pair to Nova Scotia, so cost is pretty close to one another.
For me these will end up in BIB's or Zigmahornets, maybe a voight pipe, I'm sure there are a few other designs out there that these will work with !! 🙂
If you had to pick from FE103E and the SPH 30x which is the better bang for the buck?
I'll pay probably within $20-30 of each other to get a pair to Nova Scotia, so cost is pretty close to one another.
For me these will end up in BIB's or Zigmahornets, maybe a voight pipe, I'm sure there are a few other designs out there that these will work with !! 🙂
I attach a screenshot of my WinISD data, hopefully it helps you 🙂
I have been meaning to try this driver out in a round shaped laminated style enclosure as a test for how my mid enclosures might sound. I cut 4 layers but haven't done any more yet, wood keeps setting on fire
. I might do my mid enclosures a different way in light of this difficulty, making shaped cuts internally only, with a box outer (not so stylish or rigid I know 🙁 ). Might still try this out with the SPH-30X though, a good test without using too much wood.
I have been meaning to try this driver out in a round shaped laminated style enclosure as a test for how my mid enclosures might sound. I cut 4 layers but haven't done any more yet, wood keeps setting on fire
. I might do my mid enclosures a different way in light of this difficulty, making shaped cuts internally only, with a box outer (not so stylish or rigid I know 🙁 ). Might still try this out with the SPH-30X though, a good test without using too much wood.Attachments
Re: since were talking about 3" er's
If you're not strapped for cash, I'd advise you to get both. I'm distance handicapped like you, I'm in Iceland. The only regrets I have had when ordering drivers is ordering too few types. I get a box of drivers, play around and have lots of fun, and then have a nagging curiosity about the drivers I didn't order.
You'll probably end up getting both FE103s and SPH30Xs anyway, in the long run 🙂
I've heard FE103s, not SPH30Xs. (I've heard TB W3-871s and Omnes Audio BB3.011 too.) The 103s were "magical", something that the TBs and Omnes drivers aren't really - those are just "very freaking good". The fostexes are pretty sensitive too, as far as I know, but they're probably more fragile than the SPH30X drivers, and IIRC they have less excursion.
airframe said:
If you're not strapped for cash, I'd advise you to get both. I'm distance handicapped like you, I'm in Iceland. The only regrets I have had when ordering drivers is ordering too few types. I get a box of drivers, play around and have lots of fun, and then have a nagging curiosity about the drivers I didn't order.
You'll probably end up getting both FE103s and SPH30Xs anyway, in the long run 🙂
I've heard FE103s, not SPH30Xs. (I've heard TB W3-871s and Omnes Audio BB3.011 too.) The 103s were "magical", something that the TBs and Omnes drivers aren't really - those are just "very freaking good". The fostexes are pretty sensitive too, as far as I know, but they're probably more fragile than the SPH30X drivers, and IIRC they have less excursion.
Re: since were talking about 3" er's
The 103 is a 4" driver. If you are going to spend the money the FE127 isn't much more. If you want a 3" the FF85K has been making some really good tunes around here lately.
dave
airframe said:
The 103 is a 4" driver. If you are going to spend the money the FE127 isn't much more. If you want a 3" the FF85K has been making some really good tunes around here lately.
dave
Thanks for the screenie - by the looks of it I was using the wrong version os WinISD (I was using the pro version)...Dr.EM said:
Anyway, I downloaded the non-pro version, and it works like a charm. 🙂
I think I'm gonna go with the yellow line, box tuned to 105Hz, 3.8l box (2 drivers). I'm probably gonna use 40mm waste tube as a port. 😀
Has anyone calculated the rear volume of the driver at all?
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