Not wanting to sound too glib, but surely this is straightforward enough - using a small woofer with low fs and Vas, large Xmax, using Linkwitz Transform EQ, accompanied by a small, high quality full-range handling everything above a few hundred Hz?
TangBand makes a 3" subwoofer
Which I believe has a resonate frequency around 55 Hz
TangBand also makes a 4" subwoofer
Which goes a little lower. I believe it is maybe around 45 Hz
More likely to reach your 50 Hz goal
You are hoping for even smaller front baffle with 2" or 2.5" speaker
and this is very possible.
Wanting a tall narrow cabinet makes sense, very easy and ideal.
another wonderful thing is all cabinets need to have depth too.
So both dreams can come true.
You simply make narrow tall baffle for 2" or 2.5"
and then use 3" or 4" subwoofer on side.
Speaker remains narrow and tall.
Which I believe has a resonate frequency around 55 Hz
TangBand also makes a 4" subwoofer
Which goes a little lower. I believe it is maybe around 45 Hz
More likely to reach your 50 Hz goal
You are hoping for even smaller front baffle with 2" or 2.5" speaker
and this is very possible.
Wanting a tall narrow cabinet makes sense, very easy and ideal.
another wonderful thing is all cabinets need to have depth too.
So both dreams can come true.
You simply make narrow tall baffle for 2" or 2.5"
and then use 3" or 4" subwoofer on side.
Speaker remains narrow and tall.
Since SPL is proportional to excursion and the square of the frequency, being flat to low frequencies would require the speaker to be capable of a lot of excursion while also being linear (const. BL etc.) enough to sound good, which are, clearly, difficult to achieve. An easier way to get around this issue is to pick a large diameter (surface) driver with much lesser excursion capability. In my opinion, at least an 8" driver (6" piston) is required to reproduce 100Hz properly, without much distortion.
There have been discussions on this topic before, for example, see the links below.
https://www.diyaudio.com/community/threads/cone-size-vs-lowest-frequency-table.234865/
https://www.diyaudio.com/community/threads/xmax-figures-to-actual-exurcsions.41044/
There have been discussions on this topic before, for example, see the links below.
https://www.diyaudio.com/community/threads/cone-size-vs-lowest-frequency-table.234865/
https://www.diyaudio.com/community/threads/xmax-figures-to-actual-exurcsions.41044/
Just to remind everyone that the required SPLs are low, 70-80 dB at 1m.
Though this may imply somewhat greater than that at the lowest frequencies. Just a quick look around, and the Peerless SLS-85S25CP04-4 looks to be a reasonable candidate 4" woofer. A couple in series would allow over 80dB at 1m at 50Hz, and it's cheap enough. The high fs is balanced by a low Vas, and the Linkwitz Transform EQ sorts the rest.
Though this may imply somewhat greater than that at the lowest frequencies. Just a quick look around, and the Peerless SLS-85S25CP04-4 looks to be a reasonable candidate 4" woofer. A couple in series would allow over 80dB at 1m at 50Hz, and it's cheap enough. The high fs is balanced by a low Vas, and the Linkwitz Transform EQ sorts the rest.
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I have flat to 50Hz in room with a pair of Visaton FRS80M speakers in Ikea salad bowls
They need a lot of DEQ to get there
When the DEQ runs out of headroom, they sound a bit thin
The first room node is 50Hz, so they don't need much output there
We live in an apartment, so don't want or need it loud
Very happy with the sound though
Brian
They need a lot of DEQ to get there
When the DEQ runs out of headroom, they sound a bit thin
The first room node is 50Hz, so they don't need much output there
We live in an apartment, so don't want or need it loud
Very happy with the sound though
Brian
I've only played with one 3" driver (Eton 3-212) but it did have GD shifts as it played 600-300hz. These shifts slow each frequency as you go lower and lower vs a larger driver where there are minimal shifts. If I remember correctly, adding more drivers does not change the group delay. It really comes down to the fact a 3" has to work damn hard to play low and the amount of effort is not linear. A larger driver can be linear in velocity across its whole range. Imagine a piano playing up the scale. With a driver with no delay shifts, it all comes from one place in space, with a small driver notes can shift around the room as it goes up. This is what I hear anyway and my experience is limited. I like both for different reasons. You might not care listening up close.
IMO low volume music lovers are the most sensitive. Once you get into the 83db range you are listening to your ear bone vibrate and lose sensitivity to decay. So I think it is safe to say you are a decay junky ... well, i am anyways. Maybe the OP is just a good neighbor.
IMO low volume music lovers are the most sensitive. Once you get into the 83db range you are listening to your ear bone vibrate and lose sensitivity to decay. So I think it is safe to say you are a decay junky ... well, i am anyways. Maybe the OP is just a good neighbor.
Here is the LF frequency response and distortion
You can see the distortion rise at 70Hz - this is due to a null in the response caused by a bay window, so we need even more power here
Brian
You can see the distortion rise at 70Hz - this is due to a null in the response caused by a bay window, so we need even more power here
Brian
Not sure which one i played with. We did a littledesktop WAW with a 3” TB woofer and FF85wk. It did not do bass as well as just the FF85wk in Frugel-Horn Lite. The bottom in a vented enclosure thou.
But the idea of a small WAW is still a good one. I’d consider Silver Flute W14, we have squeezed it into a 5 litre miniOnken.
dave
This thread went a bit sideways, which I expected, you guys went in two directions, one is way too technical with graphs for me to grasp, the other is trying to fit a square into a round hole with other size or design alternatives.
It’s pointless to get into too much technical aspects of Theil parameters because no one can agree on priorities from A to Z, too many thresholds where one priority overtakes another, so it’s waste of time in going down the rabbit hole for me to spend time educating my self on too much technical stuff.
This is why I ask simple questions like, can you hear a 2-3db peak from close distance if your system is not entirely flat.
Let me make it much harder on your guys.
This is why I wanted two 3" drivers in parallel up to 120hz or so, both need to be in the 2mm – 2.5mm Xmax so the low end is not deep but tight in case I have to boost it by 10db - 20db to get to 70 -80db range.
Synthetic cone materials can go deeper and tighter and stretch more without breaking but they don’t sound good especially at 1-2 feet, too sterile.
I already have two potential drivers picked out, but that’s not the point, we do not listen with eyes to look at graphs, we listen with ears. So if a graph shows peaks and valleys of 1-4db in certain spots, maybe we do not hear it so why focus on graphs so much.
At this stage I’m only interested in finding out one question.......How can you take one driver and make it play certain frequencies at one level of DB and then have it’s certain frequencies play at another level of db without noticing it or resorting to octave slopes…not sure if that is even possible, maybe all EQ types or solutions out there are only octave slope based.
Is there an L-pad with a single slope but not ocatve slope that multiplies and gets quiter with each octave, so lets say one 6db slope and that's does not go down in db and muliplies with each octave.
So far there were two options mentioned Linkwitz Transform EQ and band pass.
Isn’t band pass non-linear with a slope that multiplies with each octave, so its not real linear drop in dbs across a range of frequencies and logic tells me it would take a lot of trial and error to figure out where to slope it and by how much, so it’s not noticeable when going past 120hz that dip from 88db down to 80db, this would need DSP which is not an option as this stage, unless there is nothing else out there.
Linkwitz Transform EQ could not find proper or simple explanation online, Keith maybe you can explain more about it in simple terms if that's even possible.
Cheers
It’s pointless to get into too much technical aspects of Theil parameters because no one can agree on priorities from A to Z, too many thresholds where one priority overtakes another, so it’s waste of time in going down the rabbit hole for me to spend time educating my self on too much technical stuff.
This is why I ask simple questions like, can you hear a 2-3db peak from close distance if your system is not entirely flat.
Let me make it much harder on your guys.
- Must be 3” – 3.5” wide upfront, so all other options with 4" or larger drivers are out the window.
- Must be not deeper then 4 “- 5 “ prefer 4”
- Height can go as high as 24”
- No sideways drivers or any other angle, not natural way of doing things, never heard a good speaker in my life with any sideways or any other unconventional design, and never will, nor there will be one that will have commercial success.
- 3” Driver, must be paper cone only and low X-max, that’s right long throw never produces tight bass, it can go lower and deeper but it’s not tight, this is why I brought up the Dunlavy SM-1 it’s category is near field where speakers go up to 8.5” drivers adn much deeper in the bass, but at 2x 6.5” its very tight sounding bass. I’m following same logic, start with tight bass sound and see how loud can you make it without coloring the sound
This is why I wanted two 3" drivers in parallel up to 120hz or so, both need to be in the 2mm – 2.5mm Xmax so the low end is not deep but tight in case I have to boost it by 10db - 20db to get to 70 -80db range.
Synthetic cone materials can go deeper and tighter and stretch more without breaking but they don’t sound good especially at 1-2 feet, too sterile.
I already have two potential drivers picked out, but that’s not the point, we do not listen with eyes to look at graphs, we listen with ears. So if a graph shows peaks and valleys of 1-4db in certain spots, maybe we do not hear it so why focus on graphs so much.
At this stage I’m only interested in finding out one question.......How can you take one driver and make it play certain frequencies at one level of DB and then have it’s certain frequencies play at another level of db without noticing it or resorting to octave slopes…not sure if that is even possible, maybe all EQ types or solutions out there are only octave slope based.
Is there an L-pad with a single slope but not ocatve slope that multiplies and gets quiter with each octave, so lets say one 6db slope and that's does not go down in db and muliplies with each octave.
So far there were two options mentioned Linkwitz Transform EQ and band pass.
Isn’t band pass non-linear with a slope that multiplies with each octave, so its not real linear drop in dbs across a range of frequencies and logic tells me it would take a lot of trial and error to figure out where to slope it and by how much, so it’s not noticeable when going past 120hz that dip from 88db down to 80db, this would need DSP which is not an option as this stage, unless there is nothing else out there.
Linkwitz Transform EQ could not find proper or simple explanation online, Keith maybe you can explain more about it in simple terms if that's even possible.
Cheers
Well, as far as the bass end is concerned, the need for "boost" and Xmax are unrelated.
For a given SPL at 50Hz (say) and a given cone size (different from driver diameter!), you need a given Xmax. That's regardless of how you got there (boost or otherwise). Here's a useful piston size calculator:
http://www.baudline.com/erik/bass/xmaxer.html
For the Linkwitz Transform, the idea is that a closed-box speaker is represented by a simple mass/spring system which can relatively easily compensated for using appropriate circuitry (or, of course DSP, which is the modern way). The Transform in effect cancels the mechanical resonance (you need to know the in-box system resonant frequency and Q) and replaces it with one at a lower frequency, as required. It's not necessary to understand all the ins and outs, but there's a fair amount of information on the internet. From the horse's mouth, so to speak (see section 9):
https://www.linkwitzlab.com/filters.htm
You should have outlined your exact requirements in post #1, but multiple small woofers with low fs/Vas and large Xmax are I'm sure available which could satisfy your needs.
For a given SPL at 50Hz (say) and a given cone size (different from driver diameter!), you need a given Xmax. That's regardless of how you got there (boost or otherwise). Here's a useful piston size calculator:
http://www.baudline.com/erik/bass/xmaxer.html
For the Linkwitz Transform, the idea is that a closed-box speaker is represented by a simple mass/spring system which can relatively easily compensated for using appropriate circuitry (or, of course DSP, which is the modern way). The Transform in effect cancels the mechanical resonance (you need to know the in-box system resonant frequency and Q) and replaces it with one at a lower frequency, as required. It's not necessary to understand all the ins and outs, but there's a fair amount of information on the internet. From the horse's mouth, so to speak (see section 9):
https://www.linkwitzlab.com/filters.htm
You should have outlined your exact requirements in post #1, but multiple small woofers with low fs/Vas and large Xmax are I'm sure available which could satisfy your needs.
Well that piston calculator 2 x3" at 78 - 80db gives 2 - 2.5mm xmax for 50hz which is in line with my target and the drivers I want to use, so it can work with my requirements. The EQ/ Filter, its just too complex to understand them too many options, not sure which one or combo of more then one would solve that 8db drop issue.
I don't want to be the bearer of bad news but if you don't want to learn much about speaker design, you are probably better off buying a pair of speakers.
Something like this comes to mind:
https://www.thomann.de/gb/ik_multimedia_iloud_mtm.htm
This will save you a lot of hassle and heartbreak .
Or alternatively, see if you can find a proven design by someone else that fits your requirements
Something like this comes to mind:
https://www.thomann.de/gb/ik_multimedia_iloud_mtm.htm
This will save you a lot of hassle and heartbreak .
Or alternatively, see if you can find a proven design by someone else that fits your requirements
MCM 55-5655 Paper /Kevlar see manufacturers measurements
https://www.newark.com/mcm-audio-select/55-5655/4-die-cast-woofer-8-ohm-rubber/dp/95Y2933
vs
post #9 & forward- measurements
https://techtalk.parts-express.com/forum/tech-talk-forum/1441425-driver-testing
Quite the difference. Looking at the manufacturers data sheet I would pass, looking at the PE Forum measurements I would look closer.
Has anyone heard these 55-5655 speakers ?
===
others
http://timfeleppa.com/speakermeasmid.html
https://www.newark.com/mcm-audio-select/55-5655/4-die-cast-woofer-8-ohm-rubber/dp/95Y2933
vs
post #9 & forward- measurements
https://techtalk.parts-express.com/forum/tech-talk-forum/1441425-driver-testing
Quite the difference. Looking at the manufacturers data sheet I would pass, looking at the PE Forum measurements I would look closer.
Has anyone heard these 55-5655 speakers ?
===
others
http://timfeleppa.com/speakermeasmid.html
You should also consider music crest factor, otherwise your drivers will definitely hit xmax at bass peaks. May be no problem for the drivers but it will probably sound bad.
Anyway, once you build the speakers let us know how they sound and if you like them!
Is there standard definition for 1.5way? example I found in quick search is 2 drivers in parallel and with a low pass on one of them.
I was pondering something similar lately, 2 of the same small fullrange driver crossed over somewhere in the middle or down low, essentially just a 2 way/WAW but I imagine using the same driver could result in sound that maintains more of the qualities of using a single full range.
Dont know if that's a thing, I'd guess it is more common to just parallel them and share the load evenly but I think this way could have it's advantages ( you can add BSC in crossover and have more tunability overall)
That gives a 6dB lift below the XO point. Near field that probably means too much.
I tend towards series wiring with a big shunt cap acoss one of them. No extra gain, less load on the amplifier at LF, with each driver only working half as hard.
I have an on=going project that does this but with 3 x Alpair 6.2PeN.
dave
In all simplicity, it is a crossover
slightly more depth a crossover that sums with a flat response at the crossover point.
It is just a 24 dB octave crossover filter with a Q of .5
Instead of using the common Butterworth filter with a Q of .7 which will cause a slight peak at the crossover peak.
Linkwitz preferred even order filters either 2 pole or 4 pole , or 12dB per octave or 24 dB per octave cutoff slopes.
The step slope of 24 dB was preferred
Your summing 2 filters so if the cutoff Q is high they wont Sum flat. There will be a frequency response peak at the crossover point.
So Linkwitz used filters with lower Q so it sums flat.
Far as your project, it is still easy to achieve.
Plenty of designs using 2x 3" drivers and a tweeter.
And yes as you know only so much bass is possible.
So yes you can boost bass with whatever EQ is built into your amplifier
You already mentioned knowledge of .5 alignment
which is a simple way to help with a little less distortion
in the bass region.
plenty of people here have designed .5 alignments
And no need to overthink it and try to invent some magical new filter.
If you yourself did a proper simulation and baffle diffraction/full space
simulation using Frequency Response Data or .FRD of your chosen driver.
You will quickly find outs its not going to be much more than a off
the shelf resistor and inductor to help improve bass response
and slightly reduce how much bass boost you will need.
other wise dont bother many have mentioned its nearfield so not as big a deal
as powering a room from a distance
and do it the same way it has always been done.
put 2 drivers in a box and turn the amplifier bass knob up or down to your preference.