New build using the Kicker EX124 as a woofer.
Kicker give their power handling using a 25Hz / LR4 at 25Hz. If I want to simplify and lower the build cost with a single capacitor bundle as the highpass setting the XO point at 25Hz seems to indicate that I won't be able to use a transient perfect box of 150l + and I'll need to use the ~99 litre box that Kicker recommend or smaller.
As it's for R&R are people going to notice the difference?
A couple of 560uF caps should give me that approximate pass point.
This is how I built the big ES154 box but I used a huge box for that which was a much lower Qtc
Kicker give their power handling using a 25Hz / LR4 at 25Hz. If I want to simplify and lower the build cost with a single capacitor bundle as the highpass setting the XO point at 25Hz seems to indicate that I won't be able to use a transient perfect box of 150l + and I'll need to use the ~99 litre box that Kicker recommend or smaller.
As it's for R&R are people going to notice the difference?
A couple of 560uF caps should give me that approximate pass point.
This is how I built the big ES154 box but I used a huge box for that which was a much lower Qtc
A capacitor may rarely act as a textbook highpass filter with a speaker system.
A series capacitor can be used to "boost" and flatten a sealed box which would normally be too small. The "boost" happens when the combination of cap reactance and speaker input impedance is lower than just the box / speaker alone and for that to work, the amplifier needs a low source impedance.
EX124 in a 150 liter box with 1170uF series capacitance hits xmax with around 15 watts input.
In the sim below I show a 35 liter box with 850uF.
A series capacitor can be used to "boost" and flatten a sealed box which would normally be too small. The "boost" happens when the combination of cap reactance and speaker input impedance is lower than just the box / speaker alone and for that to work, the amplifier needs a low source impedance.
EX124 in a 150 liter box with 1170uF series capacitance hits xmax with around 15 watts input.
In the sim below I show a 35 liter box with 850uF.
Attachments
Let me re-open Jeff Bagbys program and run the numbers again as I think I was happy enough with a 90 litre box
I get 70watts at X-Max when using ~1100 uF in a 90litre box but X-Damage is about double the X-Max so peaks of 150W could be OK and that would be ~110dB.
The intended midrange needs at least a 30 litre enclosure so these were never going to be small boxes.
I'd be happy with the 27Hz F-10 in this simulation
The intended midrange needs at least a 30 litre enclosure so these were never going to be small boxes.
I'd be happy with the 27Hz F-10 in this simulation
27Hz would be great and even cover a lot of theater organ CDs. I wonder why the big difference between Jeff's program and hornresp? (did
I make a bad entry ?)
I make a bad entry ?)
Series Capacitor considered just a 1st order filter?
First Order filter wont reduce cone excursion below tuning frequency
very well.
It can help a little.
* edit* Cone excursion seemed to resemble a closed box in the horn response graph.
then I realized you guys were modeling a closed box ...
First Order filter wont reduce cone excursion below tuning frequency
very well.
It can help a little.
* edit* Cone excursion seemed to resemble a closed box in the horn response graph.
then I realized you guys were modeling a closed box ...
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Yup, and that's going to be the "feature" behind my next build (once this lockdown is over). 1 cu.ft. boxes holding 12" drivers that can get down flat to 30 Hz. Perfect combination of driver parameters and series capacitance.
Shoot for a Qtc of 1.1, and use preferably a Qms between 7 and 10. High Xmax required.
Good luck!
Wold
Good luck!
Wold
Are you using a separate power amp? If so then just use a PLLXO or a cheap second hand analogue line level xover unit pre sub poweramp.
Brett if that question is asked of me ? No these are passive all the way and will be gifted when finished to my bass player daughter, an impoverished late home buyer
Yes, it was asked of you MD. Why not add the PLLXO between the pre and power stages or in an effects loop? Much simpler.
As a 6 string bass player (B-C tuning) and long time PA owner / designer / builder (now sold), you don't want 25Hz near a stage as it will set everything rattling and just waste power. My PA was hard HPF'd at 40Hz minimum and sometimes higher, LR24.
On a standard scale 34" bass the fundamental tone is determined by the 2H and up until at least A1, or the open A string and then the fundamental doesn't become dominant for a while, and that was measured on my extremely rigid carbon fibre Status bass, not some substantially less rigid Fenderish clone which will be even worse for the 1H
Many bass cabs don't go down anywhere near 40Hz let alone 25Hz. The venerable (and horrible) Ampex fridge 4x and 8x10 cabs start to roll off close to 70Hz. Many others run similarly high roll offs to get the cab as small as possible to transport it. I've had many people comment on the deep bass on my personal cab, and I run it usually without the bass boost I designed in, so it rolls off from 60Hz, and EQ'd flat 40Hz.
Find a way to EQ at line level, not worry about it or run it sealed.
A car sub will likely run out of steam above 300Hz or so, or at least sound bad, so what are you running above it to get the harmonic spectrum?
As a 6 string bass player (B-C tuning) and long time PA owner / designer / builder (now sold), you don't want 25Hz near a stage as it will set everything rattling and just waste power. My PA was hard HPF'd at 40Hz minimum and sometimes higher, LR24.
On a standard scale 34" bass the fundamental tone is determined by the 2H and up until at least A1, or the open A string and then the fundamental doesn't become dominant for a while, and that was measured on my extremely rigid carbon fibre Status bass, not some substantially less rigid Fenderish clone which will be even worse for the 1H
Many bass cabs don't go down anywhere near 40Hz let alone 25Hz. The venerable (and horrible) Ampex fridge 4x and 8x10 cabs start to roll off close to 70Hz. Many others run similarly high roll offs to get the cab as small as possible to transport it. I've had many people comment on the deep bass on my personal cab, and I run it usually without the bass boost I designed in, so it rolls off from 60Hz, and EQ'd flat 40Hz.
Find a way to EQ at line level, not worry about it or run it sealed.
A car sub will likely run out of steam above 300Hz or so, or at least sound bad, so what are you running above it to get the harmonic spectrum?
Barf. Because
Folks see electric filter theory, a capacitor gives a 1st order highpass, and conflate that into using it on a woofer. However a woofer's impedance is NOT like the resistor the filter theory presumes. So
- Excursion might be reduced some, which I'd observed
- But it doesn't really work, as I found out when I had to redesign a passive filter which was for adding a subwoofer passively to a fullrange amp and "highpass" the satellites.
- I suppose if the frequency was low compared to the impedance peak at resonance maybe it might work-but it wouldn't cut so much excursion either.
- My recollection was the capacitance + impedance peak made an ugly load to the amp. @freddi, (1) What frequency "should" be the corner frequency of the capacitor you modeled? (2) Can you show the impedance curve with/without the capacitor? I'd be very curious.
Anyway @moondog55 yeah I'd much rather stick a Harrison Labs filter Parametric Crossovers-or even an actual electronic version, though I don't know one offhand-inline somewhere before the power amplification.
Brett I'll be using a cheap but very good treated paper cone driver from Tandy/RadioShack nominally an 8" driver but actually measures 188mm and the Vifa D26 aluminium coned tweeter the woofer will be sealed . The Kickers were cheaper than the Peerless 12" I was going to use with very similar specifications and quick modelling
A Tarkus Homage speaker and it will get described in the Multi-way section as I build it.
A Tarkus Homage speaker and it will get described in the Multi-way section as I build it.
@ Head-unit
I know it's driver dependent but the high value cap as a first order High pass can work very well in a small sealed box. I just wasn't sure that this driver*box combo was worth using with one.
I have the caps on the shelf so I don't have to buy any and if I did it's much cheaper than any import from the USA due to the high cost of postage and the added GST at the border if it gets caught up in the system
@Brett. She listens to quite a bit of Bass&Drums CDs at home and some of those recordings have large subsonic synthesizer tones, one of her compilation albums called "Jungle Beats" really pushed my own system and shakes the house at moderate volume so I wanted to be able to come a bit closer to that than the small 6" woofers in her current speakers.
Thanx all for the input
I know it's driver dependent but the high value cap as a first order High pass can work very well in a small sealed box. I just wasn't sure that this driver*box combo was worth using with one.
I have the caps on the shelf so I don't have to buy any and if I did it's much cheaper than any import from the USA due to the high cost of postage and the added GST at the border if it gets caught up in the system
@Brett. She listens to quite a bit of Bass&Drums CDs at home and some of those recordings have large subsonic synthesizer tones, one of her compilation albums called "Jungle Beats" really pushed my own system and shakes the house at moderate volume so I wanted to be able to come a bit closer to that than the small 6" woofers in her current speakers.
Thanx all for the input