This is pretty interesting they're so close, cheers! I seem to recall when I built a tapped horn recently (THAM15) I discounted the Rosso because of the (relatively) higher QTS and went with a Lorantz 15" which had more orthodox looking TH friendly parameters. However the Rosso actually models pretty nicely here in Art's cabinet! As you noted earlier the 9mm xmax becomes the limiting factor for the Lorantz in this case. It does sim and perform well but Hornresp tells me it's at the excursion limit at around 6 or 700 watts depending on the high pass setting. I've never pushed it that hard in real life.
The budget driver options are indeed reasonably limited in these parts due to the cost of getting the European and US heavy hitters down here so it's great to see these Indonesian drivers which we can get our hands on looking good in cabinet sims. 🙂
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- 4″ split copper voice coil wound on fiberglass former
- Weather-resistant paper cone and dust cap
- Whatever you gather from that, it does not imply glass fibre or kevlar etc. was mixed with paper.
It does state in the product page glass fibre reinforcement used in the pulp. Although I'm not sure why it isn't listed on the actual spec sheet.
Yeah , max excursion is Xlim..or Xmech.
You can get past Xmax real easy...but you will have more the, once you hit Xlim, that's it, some more and you destroy the driver.
It runs out of motorforce and the suspension gets tighter and tighter after ‘xmax’ . Or maybe Xvar in B&C drivers?
I can’t seem to get my B&C(18ds115) former to bottom out , but you can definitely hear the spider run out of sphincter muscle
I can’t seem to get my B&C(18ds115) former to bottom out , but you can definitely hear the spider run out of sphincter muscle
B&C's Xvar is the excursion at which the force factor (Bl), or the total suspension compliance (Cms), or both, drops to less than 50% of their small signal value, pretty much the end of "clean" response.
The 18DS115 has 14mm Xvar, but 30mm Xlim.
B&C, and most "modern" woofer's suspension travel sets Xlim/Xmech, rather than the voice coil former hitting the back plate.
That said, always a good idea to push the driver by hand to see what stops it, since the voice coil former hitting the back plate can be a "one and done", and was the end to many "old school" loose suspension drivers hit with high power.
Art
The 18DS115 has 14mm Xvar, but 30mm Xlim.
B&C, and most "modern" woofer's suspension travel sets Xlim/Xmech, rather than the voice coil former hitting the back plate.
That said, always a good idea to push the driver by hand to see what stops it, since the voice coil former hitting the back plate can be a "one and done", and was the end to many "old school" loose suspension drivers hit with high power.
Art
I ‘instantly’ bottomed the heck out of a dayton 256ho4 once (accidentally/ignorantly) with the aluminum cone. It was a uniquely scary noise. Former must be rigid too ? Aluminum or fiberglass maybe. Sound like a air cooled vVWmotor detonating in the California desert heat
It's been a while but I'm feeling the call to build some subs again and I like the B Low Rider design. I have four Low Rider 18” speakers just waiting for a new home.
I thought I read somewhere a dimension change to fit a pair of 18s in the B-Lows ? Can't seem to find it now.
Would it be better to build four single driver cabs with Peavey 18s, or stay with a pair of twin driver units?
Any pointers greatly appreciated.
I thought I read somewhere a dimension change to fit a pair of 18s in the B-Lows ? Can't seem to find it now.
Would it be better to build four single driver cabs with Peavey 18s, or stay with a pair of twin driver units?
Any pointers greatly appreciated.
Well...the dual driver cabinet is bigger and heavier, singles are easy movable by one man band, however dual driver cabinets have more sensitivity, and if you feed em enough power more efficient than singles.
It is depend what you want to achieve, ask Art if he can modify it for dual 18"s and I will be glad to draw it.
It is depend what you want to achieve, ask Art if he can modify it for dual 18"s and I will be glad to draw it.
The design was for the 15.25" diameter Low Rider, so all the dimensions that are 30.5" (2x15.25) would need to be increased to ~36.25 (2x18.125").
More truck pack options with four cabinets than two, but increases overall weight.
The 15" and 18" Low Rider use the same motor, so the "saddle" dip in frequency response between 40 and 90 Hz would be deeper.
size and weight isn't a problem as these won't be moved much... a lower corner than the simple BR boxes they are in would be fun though 😊
The "Low Rider" Fb is around 35Hz, ~2Hz lower than the Keystone.
You already proved the 18" Low Rider doesn't have the guts for a low Fb in a tapped horn:
Why not lower your BR Fb by extending their ports?
Art