Using REW and a good mic, I'd just do an FR sweep and look for where the distortion starts to increase significantly. Then use that to determine the best HP frequency and voltage limiting. as the driver is more likely to be excursion-limited in the passband (and definitely below it), and this will show up in the THD measurements.
It is built out of the original thin ply - I haven't given it much thought - I just asked here because I figured someone already had. I have a friend that has 2 and wondered how they would do in a SS15.
Based on your comment it seems like it would be less efficient with the same power as the 3015 and need thicker ply to accept more power?
Based on your comment it seems like it would be less efficient with the same power as the 3015 and need thicker ply to accept more power?
The Xmax/Xlim of the 3015lf and 4015lf are so similar as to be of no concern.
The 4015LF's heavier cone may be slightly "cleaner" sounding at higher excursions.
Whether it's slight sensitivity loss would amount to more than the difference in thermal compression between the drivers would be an interesting comparison.
In either case, more bracing and thicker plywood will improve the sound.
Art
My question on the cabinet construction really related to if another driver with more excursion would be an option. The SS15 speakers you have are as the original construction & driver and are fairly optimal as is. I doubt that a more capable driver with more excursion would work well in the thin wall cabinet. The 4015lf would just make the speakers heavier, and as they can only shift slightly less air than the 3015lf would not make them louder.
!0 years ago Jbell said'Single sheet TH challenge
'Don't remember exact posts, but they've been discussed. Kappa pro 15lf2 is the budget winner a db or so down from 3015lf, 4015lf is the output winner with a 4" coil and a db or so up from the 3015lf.
Both iron magnets, both heavier. 3015lf is still the lightweight king.,
So maybe its true that the 4015lf has less thermal compression. But 1db is not really good value improvement.
'Don't remember exact posts, but they've been discussed. Kappa pro 15lf2 is the budget winner a db or so down from 3015lf, 4015lf is the output winner with a 4" coil and a db or so up from the 3015lf.
Both iron magnets, both heavier. 3015lf is still the lightweight king.,
So maybe its true that the 4015lf has less thermal compression. But 1db is not really good value improvement.
UPDATE - So i finally got to use my 4x = 3015lf loaded SS15s and all i can say is wow!!! The room I was in I am very familiar with and have DJed in almost 100 times over the last 15 years. I have never experienced bass like this, I have used 4 x 18"bass reflex numerous times in this room and never "felt" it like this!!!!
Crossed @ 40hz to 130hz
Played mostly Top 40 and Pop EDM remixes. I could feel the bass in my chest up on the stage which I never felt before using bass reflex. Out on the dancefloor it was like a Miami nightclub.
Here are a few pics of the system.
Tops are 4x6" RCF NX-L24 copies I made
I would like to thank JBELL and the other contributors on this forum for a great design.
**** On a side note - the elevator was broken at this facility so we had to carry up 2 flights of stairs...the lightweight of these subs made that slightly less painful!!! (glad I didn't swap to 4015s like I asked in a recent post)
. Crossed at 80hz.
Crossed @ 40hz to 130hz
Played mostly Top 40 and Pop EDM remixes. I could feel the bass in my chest up on the stage which I never felt before using bass reflex. Out on the dancefloor it was like a Miami nightclub.
Here are a few pics of the system.
Tops are 4x6" RCF NX-L24 copies I made
I would like to thank JBELL and the other contributors on this forum for a great design.
**** On a side note - the elevator was broken at this facility so we had to carry up 2 flights of stairs...the lightweight of these subs made that slightly less painful!!! (glad I didn't swap to 4015s like I asked in a recent post)
Attachments
It is hard to explain how effortless these tapped horns sound. They may lack the very lowest frequencies but they can be used with minimal limiting and keep up with the rest of the system- which with gives an very dynamic sound.
BTW I would investigate if you can maybe use a lower High Pass. I would of thought that 35Hz 4th order butterworth would be adequate, and give just a bit more,
BTW I would investigate if you can maybe use a lower High Pass. I would of thought that 35Hz 4th order butterworth would be adequate, and give just a bit more,
It is hard to explain how effortless these tapped horns sound. They may lack the very lowest frequencies but they can be used with minimal limiting and keep up with the rest of the system- which with gives an very dynamic sound.
BTW I would investigate if you can maybe use a lower High Pass. I would of thought that 35Hz 4th order butterworth would be adequate, and give just a bit more, View attachment 1011817
I have ran two of these crossed at 35hz before but not near their limits. I knew I would be approaching limit since it was NYE and I thought I had read on here that 40hz was a good safe point for the 3015s so I adjusted it to 40hz before the party just to be safe.
I may try them at 35hz next time. Thanks for the comment.
funny thing HP filters.... sometimes lower is better. I've come to the thought that it needs to be low enough to get sufficient excursion to cool the motor without exceeding. I use 35.
Awesome!! that the SS15 is still alive! thanks JBELL for your contribution to the PA scene, what limiter settings you have used ? right now the 3015LF is 240 bucks , did you add extra bracing to yours ? what amp are you using to drive them. i found a guy here locally that can cut the wood for me.
I ran them with a Behringer NX3000D, 2 per side.
2 on each channel at 4 ohms per side. (8+8 parallel)
I have sold the amp but i believe i limited it to 1000 watts per channel in the internal settings in the amp.
I currently have these loaded cabinets for sale (definitely not due to performance). I just built some 21" paraflex subs using B&C 21sw152s. These SS15s gave me the fever and pack space was recently expanded so the compactness of these was no longer necessary.
South Carolina
https://www.diyaudio.com/community/threads/4-jbell-ss15s-for-sale-south-carolina.383097/
Price is negotiable for this community.
Hello all. I recently found this site and have been ferociously devouring this thread... so far I'm up to page 86. Thank you so much for the extreme amount of knowledge I have already gleaned from you generous people and your experiences! I have gotten into this while on a vacation and can't wait to get back so I can start playing around with HR.
I am somewhat new to the very technical end of speaker design but have been in audio production and synthesizer design for decades so I am picking it up fairly quickly. I am enamored with the idea of JBell's SS15 and TH subs in general. I am hoping that I could get a quick piece of advice/direction from one (or more) of you so that I can at least head in the right direction.
I am in the beginning stages of my plan to build some subs as I have recently come into possession of four Eminence Omega Pro 15A drivers. I am concerned that the SS15 and possibly a TH design in general may not be suitable for these drivers as XMax is 4.8mm, or if this is not a problem with the SS15 since Fs of the driver is 33Hz...?
I will be running mainly electronic music through the subs, and would love as much LF extension as is reasonably feasible. Amp will be Crown XTi 4000.
Am I barking up the wrong tree with this cab design and this driver?
Thank you all for what you do.
Thomas
I am somewhat new to the very technical end of speaker design but have been in audio production and synthesizer design for decades so I am picking it up fairly quickly. I am enamored with the idea of JBell's SS15 and TH subs in general. I am hoping that I could get a quick piece of advice/direction from one (or more) of you so that I can at least head in the right direction.
I am in the beginning stages of my plan to build some subs as I have recently come into possession of four Eminence Omega Pro 15A drivers. I am concerned that the SS15 and possibly a TH design in general may not be suitable for these drivers as XMax is 4.8mm, or if this is not a problem with the SS15 since Fs of the driver is 33Hz...?
I will be running mainly electronic music through the subs, and would love as much LF extension as is reasonably feasible. Amp will be Crown XTi 4000.
Am I barking up the wrong tree with this cab design and this driver?
Thank you all for what you do.
Thomas