Hi all, I have two listening rooms (upper ca 3,2 x3,5 m home office and a cellar man-cave 3,4 * 4,6 m) in my house and three loudspeaker systems. One of them is Lowther DX-2 in a Hedlund horn, the other is a Yamamoto YS-500 clone and the third is three(or two) way bi-amped system composed of a Peavey FH-1 clone, midrange horn (JBL 2445 or cone) or a FR OB and HF (small horn or tweeter).
All the systems are sonically out of their cost league and I enjoy them all in a sense. But from what I wrote, you may guess what I am missing - the deep bass. I am kind of out of space in both rooms, therefore I need the subwoofers to be small and deep and will not mind if they are not too loud. Most of the listening is with my family at home and that means low volume. 100 dB peak would be more than enough since all the speakers are at least around 95 dB/W sensitivity and my average listening power is usually below 1 W.
The YS-500 clone is the deepest of them all and that would be almost sufficient. Therefore my design goals would be 30 - 100 Hz (max, more like 30 - 80) and 100 dB at full power. I am open to have either 1 large or more smaller subs. I can use class D modules (ca 100 W mono into 4 ohms) or around 150 W/ch with my current amps.
I am open to any suggestions. The cellar room might accept something large like a single fold TH if it is really worth it.
And I would prefer EU available drivers. Thanks🙂
All the systems are sonically out of their cost league and I enjoy them all in a sense. But from what I wrote, you may guess what I am missing - the deep bass. I am kind of out of space in both rooms, therefore I need the subwoofers to be small and deep and will not mind if they are not too loud. Most of the listening is with my family at home and that means low volume. 100 dB peak would be more than enough since all the speakers are at least around 95 dB/W sensitivity and my average listening power is usually below 1 W.
The YS-500 clone is the deepest of them all and that would be almost sufficient. Therefore my design goals would be 30 - 100 Hz (max, more like 30 - 80) and 100 dB at full power. I am open to have either 1 large or more smaller subs. I can use class D modules (ca 100 W mono into 4 ohms) or around 150 W/ch with my current amps.
I am open to any suggestions. The cellar room might accept something large like a single fold TH if it is really worth it.
And I would prefer EU available drivers. Thanks🙂
I will reply myself🙂 As a first trial, I will buy some second hand active subwoofers to test the concept of multiple subs.
And I think I will report the progress as my experiments go on, someone may be interested🙂
The YS-500 clones do not need deeper bass. The Hedlund horns do, maybe it is because of the small room which is not optimal for them. I took an old BR passive subwoofer from a home cinema and with a class D amp without crossover I just tried what would be the difference.
Even with this very cheap boom box, I got lows like the YS-clones with Lowther magical imaging. Since the YS clones are open baffle sort of U-frame, I may actually try to use the bass part as subwoofers with the H-horns - it should work with a little processing. I actually do not need to do anything with them, just feed them with a lowpassed signal, maybe with some delay to compensate for the distance due to slant ceiling.
The easiest for now is to get an active sub for temporary use as it may serve later as one of the multiple random subs.
The YS-500 clones do not need deeper bass. The Hedlund horns do, maybe it is because of the small room which is not optimal for them. I took an old BR passive subwoofer from a home cinema and with a class D amp without crossover I just tried what would be the difference.
Even with this very cheap boom box, I got lows like the YS-clones with Lowther magical imaging. Since the YS clones are open baffle sort of U-frame, I may actually try to use the bass part as subwoofers with the H-horns - it should work with a little processing. I actually do not need to do anything with them, just feed them with a lowpassed signal, maybe with some delay to compensate for the distance due to slant ceiling.
The easiest for now is to get an active sub for temporary use as it may serve later as one of the multiple random subs.
I'm planning to do that as well. The multiple sub theory is strong. I want to experiment in the real world.
Take a good look at the SB Acoustics SB23MFCL45 -4 or -8. I am using one (4 Ohm version) in a closed box with an older Hypex plate amp. The box volume is about 0.9 cu ft (25.5 liters). The Hypex can deliver up to 175 WRMS into 4 Ohms. I am getting all the way down to 16 Hz at a very satisfying level. I do have a smaller listening room so maybe 2 of the 8 Ohm version (in parallel) might work better for you if you need higher output, larger room, etc. One problem I had was the "subwoofer" output from my main amp. wasn't a very high level so I inserted an in-line pre-amp that is adjustable gain. I usually need to boost the level to the Hypex input +5 to +8 dB. Of course, the Hypex has many variable adjustments for EQ freq and boost, X/O freq, etc. You will need to have some form of low-pass, EQ, etc. if you are using "regular" power amplifiers not specifically designed for bass management.
Thanks, that sounds interesting, I actually considered a sealed subwoofer with Peerless SLS 12", the amp is a D-class stereo board, SB Acoustics should be easy to get and it should be more compact.
I wanted to try freeDSP as the sub controller. It worked nicely, but then it failed somehow. Out of desperation, I put a line level 1st order passive filter on a breadboard. Not ideal, but works better than nothing.
By the way, I got a new amp today, a Denon PMA1500AE and the sound improvement was beyond all expectations. And cheating a bit with the bass control, I may do completely without a sub when listening at lower levels in the upper room with the H-horns.
I wanted to try freeDSP as the sub controller. It worked nicely, but then it failed somehow. Out of desperation, I put a line level 1st order passive filter on a breadboard. Not ideal, but works better than nothing.
By the way, I got a new amp today, a Denon PMA1500AE and the sound improvement was beyond all expectations. And cheating a bit with the bass control, I may do completely without a sub when listening at lower levels in the upper room with the H-horns.
For the upper room, I would like the outer dimensions to be max 50x50x50 cm. The lower room could accept something like a TH with slim footprint and max. 200 cm long (or rather 190 cm so that I can manipulate with it easier).
As a maximum, I think I could fit a 100x100x20 - 30 cm sized TH or maybe even two, but that is only possible along the walls in the corners.
If placement in the back corners is not a problem, I could go for ca 100 x 50 x 70 cm if masked as furniture.
But I would prefer as small as possible to get around 100 dB peak at 25 Hz (or at least at 40 Hz with reduction below that) - and I do not mind having a very powerful pro amplifier if needed (passive cooling or with a silent fan) and the freeDSP will be used for any processing needed.
As a maximum, I think I could fit a 100x100x20 - 30 cm sized TH or maybe even two, but that is only possible along the walls in the corners.
If placement in the back corners is not a problem, I could go for ca 100 x 50 x 70 cm if masked as furniture.
But I would prefer as small as possible to get around 100 dB peak at 25 Hz (or at least at 40 Hz with reduction below that) - and I do not mind having a very powerful pro amplifier if needed (passive cooling or with a silent fan) and the freeDSP will be used for any processing needed.
You have to know about Hoffman's Iron Law; Small box, Deep extension, High Sensitivity; Pick 2. You can't have the 3rd.
So- you want a small box 20" cube or less, that does 100dB at 25Hz. With the size and extension requirements, you're likely looking at either a sealed or 4th order bandpass with a high-mass/low-Vas/mid-Q driver and about 500W with some minor boost. The wattage still allows high output even though the sensitivity is lower. You'll need it to keep up with your high-sensitivity mains.
I think my Overdrive10 subwoofer will fill the small box needs. You can get the UM10 and RSS315PR in the UK or even Amazon, or from Sound Imports. The Yung SD500-6 plate-amp is available at ukaudiomart. It's smaller than your 20" cube in every dimension, and has bandwidth of 22-65Hz with boost acoustically. You can rolloff the high end with the active filter to make it steeper if desired. Basically, it's +6dB at 25Hz from the amp.
There is a thread for it here at DIYaudio.
Later,
Wolf
So- you want a small box 20" cube or less, that does 100dB at 25Hz. With the size and extension requirements, you're likely looking at either a sealed or 4th order bandpass with a high-mass/low-Vas/mid-Q driver and about 500W with some minor boost. The wattage still allows high output even though the sensitivity is lower. You'll need it to keep up with your high-sensitivity mains.
I think my Overdrive10 subwoofer will fill the small box needs. You can get the UM10 and RSS315PR in the UK or even Amazon, or from Sound Imports. The Yung SD500-6 plate-amp is available at ukaudiomart. It's smaller than your 20" cube in every dimension, and has bandwidth of 22-65Hz with boost acoustically. You can rolloff the high end with the active filter to make it steeper if desired. Basically, it's +6dB at 25Hz from the amp.
There is a thread for it here at DIYaudio.
Later,
Wolf
Thanks, I will check it out.
Edit: definitely not a cheap option, but the cost would be still reasonable and both the woofer and PR can be bought directly in EU. So the Overdrive10 goes high on my list. Do I understand it correctly that I can get slightly more efficiency with the bandpass compared to sealed?
Edit: definitely not a cheap option, but the cost would be still reasonable and both the woofer and PR can be bought directly in EU. So the Overdrive10 goes high on my list. Do I understand it correctly that I can get slightly more efficiency with the bandpass compared to sealed?
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Unfortunately, no, it's not cheap. I was able to get some discounts as I procured parts. The benefits of the bandpass are:
- a slight increase in efficiency and therefore sensitivity as a system. 1dB in this case. Bandpasses can be modeled for loss and wider bandwidth, or gain and narrower bandwidth. In this case the boost helps the bottom end, and the particular driver allows both this and the slight gain while keeping the bandwidth rather wide at 22-65Hz.
- a very low harmonic distortion as a system. This is a very clean subwoofer.
- The PR eliminates port noise as compared to a vented or ported reflex or bandpass.
- Steeper inherent upper rolloff due to the acoustic rolloff plus active lowpass. You could run without the active lowpass, but it's nice to have it available. It can literally get out of the way of anything it blends with as the combined 8th order rolloff decreases quickly.
- second order lower rolloff for better room blending.
- sealed air-spring for better driver control.
- no unloading under tuning as in a vented system.
- in this design, the peaking (boosting) infrasonic highpass prevents the overexcursion potential.
Really the only downsides of this design are the shake of the system and the cost. You may want spikes for carpet, a weighted base to keep it more stationary, or even a heavier cabinet material.
Let me know if you require any more information,
Wolf
- a slight increase in efficiency and therefore sensitivity as a system. 1dB in this case. Bandpasses can be modeled for loss and wider bandwidth, or gain and narrower bandwidth. In this case the boost helps the bottom end, and the particular driver allows both this and the slight gain while keeping the bandwidth rather wide at 22-65Hz.
- a very low harmonic distortion as a system. This is a very clean subwoofer.
- The PR eliminates port noise as compared to a vented or ported reflex or bandpass.
- Steeper inherent upper rolloff due to the acoustic rolloff plus active lowpass. You could run without the active lowpass, but it's nice to have it available. It can literally get out of the way of anything it blends with as the combined 8th order rolloff decreases quickly.
- second order lower rolloff for better room blending.
- sealed air-spring for better driver control.
- no unloading under tuning as in a vented system.
- in this design, the peaking (boosting) infrasonic highpass prevents the overexcursion potential.
Really the only downsides of this design are the shake of the system and the cost. You may want spikes for carpet, a weighted base to keep it more stationary, or even a heavier cabinet material.
Let me know if you require any more information,
Wolf
Anyway, for what it is, the cost is reasonable. And I really like the design and thoughts behind. Soundimports will have at least free shipping on this order🙂
I will most probably build a passive version - is it worth installing a heatsink for the closed chamber - like a steel plate instead of the plate amp? I am thinking it would leave me the option for a later upgrade to active.
I will most probably build a passive version - is it worth installing a heatsink for the closed chamber - like a steel plate instead of the plate amp? I am thinking it would leave me the option for a later upgrade to active.
Steel isn't a great heatsink as opposed to aluminum, but you could plate it if you want to. Just be sure to add +6dB at 25Hz, and hope you have enough power to cover the boost since it quadruples the power required in that range.
Wolf
Wolf
4th order band pass
Hi there 🙂
Just bump to this thread looking for options for my SB collecting dust driver,
Is there’s a chance Mr Wolf could help me design 4th order band pass subwoofer for SB23MFCL45-4 I can build it but I don’t know how to design the box properly any info or direction where I can look for the info would be great
Thanks in advance
Hi there 🙂
Just bump to this thread looking for options for my SB collecting dust driver,
Is there’s a chance Mr Wolf could help me design 4th order band pass subwoofer for SB23MFCL45-4 I can build it but I don’t know how to design the box properly any info or direction where I can look for the info would be great
Thanks in advance
That's an 8" SB. I've found that this kind of system really benefits from more Sd than an 8" woofer. Unibox has a 4th order Bandpass model frame. It's an Excel sheet you can DL for free. If not, I bet Jurgen's website will do it, or HornResponse can do it. It would also benefit from having a woofer that boost is okay, or a sealed box is better performance.
You would also have to provide more information of application for design. You might want to start a new thread so more than one builder can assist you in different ideas or simulations. Not everyone will design the same way, and tradeoffs are not usually the same person to person.
Later,
Wolf
You would also have to provide more information of application for design. You might want to start a new thread so more than one builder can assist you in different ideas or simulations. Not everyone will design the same way, and tradeoffs are not usually the same person to person.
Later,
Wolf
I got some good offer for 4 pcs of Peerless P830669 drivers (essentially unused and half the new price) - that is all 4 at the price of one UM10. Any idea with these? I think these would work well sealed (ca 30x30x30 cm cube for each and Linkwitz transformed) or even for dipole. I think I have kind of overestimated the 105 dB subwoofer level needed, since a 40W D-class amp is overly loud with a small and ultra cheap 6" ported subwoofer from a home cinema set.
In 2.4ft^3, the SLS12 will only go to 51Hz. Your box is not even a cubic foot, and the Xmax will come up short if you are going to LT the low end in a 1ft^3 box. I've not modeled this, but the UM10 has more than twice the Xmax as the SLS12. In a quad, you might be alright as less Xmax is required with more drivers.
Wolf
Wolf