If you really believe that form follows function then you wouldn’t be trying to use very small diameter drivers to produce low frequencies. They cannot do it and sound good at the same time. There will be excessive distortion.
Tim405 explains it quite well in Post #51 with the following statement:
“You ain't going to make a speaker which sounds good utilizing a 3 inch normal throw paper (fr) driver playing to 50hz in a sealed cabinet. The distortion will be horrible (I know because I have done similair tests) if that doesn't bother you enough (it will because at 80db the distortion will be audible with probably 20% or more distortion and completeling bleeding in the mids and highs causing 'muddy' sound) the chances of destroying the driver due to over excursion or excessive heat will be very high with 9db of boost.”
You would be well advised to also reread Posts #6, #9, #23, #35, and #68 all written by knowledgeable people that caution about the likely distortion resulting from trying to squeeze low frequencies out of small diameter drivers that were never designed or intended to produce those frequencies to begin with.
You seem to be completely ignoring these hard facts so perhaps distortion is not important to you anyhow. Just a note of caution for you to consider.
Paul Carmody designed a bluetooth speaker that works as 2 separates aswell. I have a pair. Goes down to 40hz I believe and 80db SPL is achieved on it up close at your distance I believe.
You can decrease the depth and make it taller if you want, have to keep the width the same though.
If you scroll down. You can see pictures of peoples separate designs that built this design, I think the there is one where the person decided to build a rather tall but skinnier speaker at the bottom, you’d like something like that?
https://sites.google.com/site/undefinition/portable-and-tabletop-speakers/sprite
You can decrease the depth and make it taller if you want, have to keep the width the same though.
If you scroll down. You can see pictures of peoples separate designs that built this design, I think the there is one where the person decided to build a rather tall but skinnier speaker at the bottom, you’d like something like that?
https://sites.google.com/site/undefinition/portable-and-tabletop-speakers/sprite
Crest factor isn't anything you negotiate in or out. It's simply a figure of "how average level and peaks relate" in a piece of music. As you are obviously not ventured in the more theoretical part of audio and speaker building and don't understand your own requirements, I suggest that you:
Good luck!
//
- build a closed box of the largest size you can tolerate
- get a high quality bass driver with the largest size you can fit
- get an amplifier with some omfh - say a good quality 50 watt one
- means to equalise the bass to you need and liking (computer?) - I suggest you insert a sharp filter below 50 Hz - say 12 dB / oct (2nd order) to protect things.
- I assume that you are not in the possession of a measurement system - EQ the sh*t out of it until you find the bass / sound that you want.
Good luck!
//
I have attached a picture of some speakers I made a while ago, for two reasons; the speakers use two 2.5 inch woven glass fibre drivers mounted back to back to cancel out reactive forces, the front is used full range, the rear comes in at below 1,000 Hz to fill out the bass.
The first reason is at first the sounded mediocre, but I recently tried them again after moding the amp ( greatly increasing the power supply capacitance ), and they sound much better - if you want to drive a few 3 inch drivers hard at 50 Hz, it's not only power ( watts ) you'll need, but also a stiff power supply. the other reason is if you have a lot of 3 inch drivers working hard, all mounted on the front, that's going to shake the cabinet. The only thing I can suggest is you have something like one of these, working full range, but standing on s stack of similar speakers ( all made in one tall enclosure ) coming in at 100 to 50 Hz. You seem to make no mention of whether they'll be close to a wall.
The first reason is at first the sounded mediocre, but I recently tried them again after moding the amp ( greatly increasing the power supply capacitance ), and they sound much better - if you want to drive a few 3 inch drivers hard at 50 Hz, it's not only power ( watts ) you'll need, but also a stiff power supply. the other reason is if you have a lot of 3 inch drivers working hard, all mounted on the front, that's going to shake the cabinet. The only thing I can suggest is you have something like one of these, working full range, but standing on s stack of similar speakers ( all made in one tall enclosure ) coming in at 100 to 50 Hz. You seem to make no mention of whether they'll be close to a wall.
Attachments
Yeah the bass SPL/extension is just physics, related to sound wavelength, and proportional to volume displacement our transducer does. Here is handy chart one can use to quickly estimate closed box woofer system SPL capability at certain frequency per available volume displacement https://www.diyaudio.com/community/threads/volume-displacement-for-spl-chart.5668/post-55869
This can give hint about the bare minimum we need to inspect to see what kind of (ideal) system is required to meet some goal.
Volume displacement is calculated simply by calculating volume the cone occupies while doing xmax, so multiply xmax with cone area. Cone area for any driver is found in datasheet (Sd), for example 3" driver (faital pro 3fe22) is about 33cm^2 and xmax is 1.83mm. Volume displacement for single 3fe22 is 33cm^2 * 0.183cm = ~6cm^3.
We see from the chart this driver alone cannot reach 80db at 50Hz no matter what since about 10cm^3 would be needed to do that. If we add another driver the volume displacement is now ~12cm^3 and now the 80db at 50Hz is physically possible but there can be other limitations that prevent this, like heating of the voice coil increasing resistance and making compression. Also the distortion near xmax is probably quite high so the sound is not too nice. Mind you this is the absolute maximum SPL we can now produce so the "average listening level" needs to be lot less for all the peaks to reproduce nicely, perhaps as low as 65db or so. So, if you pop out your cellphone SPL meter app and measure SPL it read something ~60-70 max with two 3" drivers before the sound gets poo. To get more volume displacement one has to use bigger / more drivers, with better motors so that other factors like compression is not hampering the performance.
From the same chart we can see how much volume displacement is needed for 50Hz 80db average (on your SPL meter) with say 15db headroom for the peaks to reproduce cleanly. This is 95db and from the chart we get roughly 50cm^3 is required. This is roughly 10 pieces of faital pro 3fe22. Single 6" 6fe200 has about similar volume displacement. Better play it safe and use 8" driver.
You can make small speakers, but the response is limited by physics. You can "cheat" by exploiting pshychoacoustics though, like every bluetooth speaker on the market does. They compress the lows and add harmonics on top to fool the hearing system to "hear" the fundamental when in reality there is not too much output below say 80 or 100Hz.
To circumvent all this, just put the speakers very close to ear to reduce the SPL requirement, like headphones, or add bigger woofers to extend the low frequency response. Or just relax on the low frequency response requirement, or add cheats like the processing mentioned. Can't cheat physics though.
Best way to get low frequency response is to use as big drivers in as big boxes as you can tolerate, otherwise it is just what you happen to get with the size you happen to tolerate. It might sound just fine, never knowing the actual numbers.
Hope it helps 🙂
ps. 50Hz has roughly 7 meter long wavelength, it doesn't fit into domestic rooms so small objects like small drivers have hardly any influence on it but the room has. On the other hand 20kHz is only ~2cm long and object roughly similar in size can influence it without problems. This in mind you could hide a ~8" subwoofer to a closet, or into a bookshelf and it would work fine as long as it is in the same room, to augment the missing lows you just are not going to get with small speaker.
This can give hint about the bare minimum we need to inspect to see what kind of (ideal) system is required to meet some goal.
Volume displacement is calculated simply by calculating volume the cone occupies while doing xmax, so multiply xmax with cone area. Cone area for any driver is found in datasheet (Sd), for example 3" driver (faital pro 3fe22) is about 33cm^2 and xmax is 1.83mm. Volume displacement for single 3fe22 is 33cm^2 * 0.183cm = ~6cm^3.
We see from the chart this driver alone cannot reach 80db at 50Hz no matter what since about 10cm^3 would be needed to do that. If we add another driver the volume displacement is now ~12cm^3 and now the 80db at 50Hz is physically possible but there can be other limitations that prevent this, like heating of the voice coil increasing resistance and making compression. Also the distortion near xmax is probably quite high so the sound is not too nice. Mind you this is the absolute maximum SPL we can now produce so the "average listening level" needs to be lot less for all the peaks to reproduce nicely, perhaps as low as 65db or so. So, if you pop out your cellphone SPL meter app and measure SPL it read something ~60-70 max with two 3" drivers before the sound gets poo. To get more volume displacement one has to use bigger / more drivers, with better motors so that other factors like compression is not hampering the performance.
From the same chart we can see how much volume displacement is needed for 50Hz 80db average (on your SPL meter) with say 15db headroom for the peaks to reproduce cleanly. This is 95db and from the chart we get roughly 50cm^3 is required. This is roughly 10 pieces of faital pro 3fe22. Single 6" 6fe200 has about similar volume displacement. Better play it safe and use 8" driver.
You can make small speakers, but the response is limited by physics. You can "cheat" by exploiting pshychoacoustics though, like every bluetooth speaker on the market does. They compress the lows and add harmonics on top to fool the hearing system to "hear" the fundamental when in reality there is not too much output below say 80 or 100Hz.
To circumvent all this, just put the speakers very close to ear to reduce the SPL requirement, like headphones, or add bigger woofers to extend the low frequency response. Or just relax on the low frequency response requirement, or add cheats like the processing mentioned. Can't cheat physics though.
Best way to get low frequency response is to use as big drivers in as big boxes as you can tolerate, otherwise it is just what you happen to get with the size you happen to tolerate. It might sound just fine, never knowing the actual numbers.
Hope it helps 🙂
ps. 50Hz has roughly 7 meter long wavelength, it doesn't fit into domestic rooms so small objects like small drivers have hardly any influence on it but the room has. On the other hand 20kHz is only ~2cm long and object roughly similar in size can influence it without problems. This in mind you could hide a ~8" subwoofer to a closet, or into a bookshelf and it would work fine as long as it is in the same room, to augment the missing lows you just are not going to get with small speaker.
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your reputation is greatly increased with the little star below your avatar!
I appreciate your contribution to the community.
k'n'h, I just now read more from the beginning 😀 So, yeah lots of good advice, and I'll repeat:
Your most important goal seems to be the aesthetics so go for it, use what drivers you want and as the low frequency response and SPL is more or less limited by the system size you ended up with, just have to take what is given, don't mind about the exact numbers. Since you don't have measurement equipment and don't currently seem to intend to have one I suggest try and see if there are some kits available you could adapt to your aesthetics.
I'll guess you are gonna end up with fine pair of speakers. If you find they lacking somehow when finished there is now a chance to do another pair or augment the existing pair with extra bass speaker(s).
Remember to have fun with the project and hobby!🙂
Your most important goal seems to be the aesthetics so go for it, use what drivers you want and as the low frequency response and SPL is more or less limited by the system size you ended up with, just have to take what is given, don't mind about the exact numbers. Since you don't have measurement equipment and don't currently seem to intend to have one I suggest try and see if there are some kits available you could adapt to your aesthetics.
I'll guess you are gonna end up with fine pair of speakers. If you find they lacking somehow when finished there is now a chance to do another pair or augment the existing pair with extra bass speaker(s).
Remember to have fun with the project and hobby!🙂
Ok,
Things went a bit sideways, with a bit of a dick-measuring contest among experts, its ok healthy ego never killed anyone, but we are wasting bandwidth.
Lets start from the beginning and establish an accurate reference:
Here is what I don't get, maybe I simply do not know what does 50hz sounds like nor do I know how loud is 80db.
For example I have pair of old cheap small desktop speakers it's a single 2.5" paper cone driver full range in each one, the speakers have this amp inside it driving both speakers:
https://quasarelectronics.co.uk/Item/3090h-3w-stereo-amplifier-module-ba5406-with-heatsink
Mine also has the three tone controls for bass, treble and volume.
When I crank the bass to max I have plenty of bass, drum, low end but it's very muddy, at about 70% on bass it's more or less ok, but still a bit muddy, but defiantly more then enough low end and low mid, the mid to top is all mud since it's an old driver and no tweeter. Treble is all the way to its max but still very muddy mid to top.
The main volume on the speaker is at it's max, on my stock macbook air I listen at about 70%, but if I max out my macbook internal volume the speakers still handle it, no distortion but I can see another 3db bump if I had it, and something will pop or distort.
So my question is, if that 3 watt amp at max 85db says 28db gain, there is a high probability my tone controls are exactly by 28db increase range up to 85db, since it's only a 2.5" driver and x-max is more or less under 3mm, how is it they are not blown or distorted, if the issue is we can't play 50hz at 80db-85db, do you think I'm actually not getting any 50hz at all and my perception of what 50hz is actually 100hz.
I mean typical drum kick I mean electronic one or from hip hop or EDM music is near 50hz, I can hear it perfectly fine on my speakers and perfect bass, muddy but it's there and no distortion.
Is mud considered part of distortion as well? When we say the word distortion, do we mean pop, crackle rattling sound from the cone or does very muddy sound also means distortion? So when you guys say you will hear distortion, maybe I’m already hearing it in a form of a muddy sound.
Why do manufacturer put FS measure, and then I see people say you can drive a driver much lower past it's FS? How is that possible, if at FS it's at it max X-max, the cone will break from the frame past anything below 120hz and past the x-max.
So that frequency curves chart-showing 73db at 50hz, it should be a straight vertical line from 120hz down wards to zero not a progressively sloping line?
My gut feeling these graphs are not as accurate as they are or too safe, maybe to avoid too many returns.
I will say this, I asked another person to model my specs on the Alpha 3-8 driver, and dear........”stv”…… you are correct he said the same thing, if I want 80db at 50hz I need to boost it by about 20db but he said his numbers don’t work, meaning at 80db 50hz the x-max is already past it’s limits on that driver.
When I look at my current cheap speakers and if in fact I’m boosting it by about 20db on bass, and its muddy, I think moving forward I can live with about 15db boost on bass at the most before it's too much muddy, so maybe my target should be 75db, the only question is we still don’t know how low does my current speaker goes with that maximum bass boost since we have no specs on the driver nor I have the tools or knowledge to measure it.
Since I’m very stubborn on aesthetics, I think the next logical choice is to search for the cleanest possible tone control on bass, not sure if it’s better done before the amp or after the amp, this is why I brought up Avalon U5, nothing is cleaner then that pre-amp it boosts the signal by 30db, but it was 30db across all frequencies not just low end, so I have no idea if that type of circuit will be muddy if it was concentrated only on low end. Bass guitar with passive pick ups run thru it sounded fantastic, I never run a full mix thru it plus I had large 3-way actives and fully treated room with bass traps that I built with the help from Ethan Winer,
very good man helped me a lot, that was a night and day change in the way my room sounded. So who know how that U5 would work without that set up.
I got spoiled early in my life with so much high-end gear, Inever paid any attention to numbers on db or hz, it's the worst thing moving forward, since I don't have the finances as I used to have, otherwise I'd spend $5k -10k on all kinds of experiments, but the dillema is you can't go back to mediocare sound after that experaince. So I actully try to listen to less music in general untill I can get something satisfactory.
One more qustion, if I went with classic 3-way, am I loosing 6db and need to boost one driver by 28db now to get to my 80db at 50hz?
Cheers.
Things went a bit sideways, with a bit of a dick-measuring contest among experts, its ok healthy ego never killed anyone, but we are wasting bandwidth.
Lets start from the beginning and establish an accurate reference:
Here is what I don't get, maybe I simply do not know what does 50hz sounds like nor do I know how loud is 80db.
For example I have pair of old cheap small desktop speakers it's a single 2.5" paper cone driver full range in each one, the speakers have this amp inside it driving both speakers:
https://quasarelectronics.co.uk/Item/3090h-3w-stereo-amplifier-module-ba5406-with-heatsink
Mine also has the three tone controls for bass, treble and volume.
When I crank the bass to max I have plenty of bass, drum, low end but it's very muddy, at about 70% on bass it's more or less ok, but still a bit muddy, but defiantly more then enough low end and low mid, the mid to top is all mud since it's an old driver and no tweeter. Treble is all the way to its max but still very muddy mid to top.
The main volume on the speaker is at it's max, on my stock macbook air I listen at about 70%, but if I max out my macbook internal volume the speakers still handle it, no distortion but I can see another 3db bump if I had it, and something will pop or distort.
So my question is, if that 3 watt amp at max 85db says 28db gain, there is a high probability my tone controls are exactly by 28db increase range up to 85db, since it's only a 2.5" driver and x-max is more or less under 3mm, how is it they are not blown or distorted, if the issue is we can't play 50hz at 80db-85db, do you think I'm actually not getting any 50hz at all and my perception of what 50hz is actually 100hz.
I mean typical drum kick I mean electronic one or from hip hop or EDM music is near 50hz, I can hear it perfectly fine on my speakers and perfect bass, muddy but it's there and no distortion.
Is mud considered part of distortion as well? When we say the word distortion, do we mean pop, crackle rattling sound from the cone or does very muddy sound also means distortion? So when you guys say you will hear distortion, maybe I’m already hearing it in a form of a muddy sound.
Why do manufacturer put FS measure, and then I see people say you can drive a driver much lower past it's FS? How is that possible, if at FS it's at it max X-max, the cone will break from the frame past anything below 120hz and past the x-max.
So that frequency curves chart-showing 73db at 50hz, it should be a straight vertical line from 120hz down wards to zero not a progressively sloping line?
My gut feeling these graphs are not as accurate as they are or too safe, maybe to avoid too many returns.
I will say this, I asked another person to model my specs on the Alpha 3-8 driver, and dear........”stv”…… you are correct he said the same thing, if I want 80db at 50hz I need to boost it by about 20db but he said his numbers don’t work, meaning at 80db 50hz the x-max is already past it’s limits on that driver.
When I look at my current cheap speakers and if in fact I’m boosting it by about 20db on bass, and its muddy, I think moving forward I can live with about 15db boost on bass at the most before it's too much muddy, so maybe my target should be 75db, the only question is we still don’t know how low does my current speaker goes with that maximum bass boost since we have no specs on the driver nor I have the tools or knowledge to measure it.
Since I’m very stubborn on aesthetics, I think the next logical choice is to search for the cleanest possible tone control on bass, not sure if it’s better done before the amp or after the amp, this is why I brought up Avalon U5, nothing is cleaner then that pre-amp it boosts the signal by 30db, but it was 30db across all frequencies not just low end, so I have no idea if that type of circuit will be muddy if it was concentrated only on low end. Bass guitar with passive pick ups run thru it sounded fantastic, I never run a full mix thru it plus I had large 3-way actives and fully treated room with bass traps that I built with the help from Ethan Winer,
very good man helped me a lot, that was a night and day change in the way my room sounded. So who know how that U5 would work without that set up.
I got spoiled early in my life with so much high-end gear, Inever paid any attention to numbers on db or hz, it's the worst thing moving forward, since I don't have the finances as I used to have, otherwise I'd spend $5k -10k on all kinds of experiments, but the dillema is you can't go back to mediocare sound after that experaince. So I actully try to listen to less music in general untill I can get something satisfactory.
One more qustion, if I went with classic 3-way, am I loosing 6db and need to boost one driver by 28db now to get to my 80db at 50hz?
Cheers.
1) Here is a few things you probably didn't know. If your speakers do really go down to 50Hz, it would sound like your ATC. 50Hz, is where you can get the thump of the T-Rex footsteps in Jurrasic park. What you heard of the kick drum is the higher harmonics, not the true 50Hz, the kick drum not only generate 50Hz pure tone, but a lot of other frequency tone. That is what you heard.
2) All being said and down, if the question is can you achieve 50Hz on 3 inch. The answer is yes. But not in the conventional way. It takes a passive radiator design, and probably a not very nice sounding midrange, because it was optimised to go low, and you need DSP. You also need somebody who knows how to optimise all these parameters together especially the DSP profile. To have an idea what I am talking about,, you can look at the various portable bluetooth boombox speaker out there from JBL, Bose etc. The design approach they used is because of that reason.
50Hz on a 3 inch is a subwoofer. You can buy a subwoofer module to do this. Something like this. I have a pair and it really works well, but it jumps all over the place.
https://www.parts-express.com/Tang-Band-T3-2190S-3-Subwoofer-Module-7-1-2-x-3-5-8-264-942
3) From a marketing perspective, what you ask is very nice and I am sure many people out there, but you are not the only marketing genius out there. If it was easily achievable, there would be a whole bunch of PC speakers that fit this description from many established PC accesories speaker makers out there. There is a reason why products like this don't exist. And BTW, that subwoofer module is not the answer for PC speaker, there is so much vibration that it bounces all over the place everytime bass is played. It literally fell of the table one time from all the vibration and jumping around.
4) One more thing, what was mentioned about crest Factor is very important. When you say, I want the singing voice to be 80 dB means the kick drum is 92db.
5) If you boosted something by 20db, that means the power you are putting is 100X higher. so if you are listening to your vocals at 1 W, your bass is coming in at 100W, if they are of the same level, but if you consider that the level of kick drum is higher than the singing voice by 12db. You would need about 1000W.
2) All being said and down, if the question is can you achieve 50Hz on 3 inch. The answer is yes. But not in the conventional way. It takes a passive radiator design, and probably a not very nice sounding midrange, because it was optimised to go low, and you need DSP. You also need somebody who knows how to optimise all these parameters together especially the DSP profile. To have an idea what I am talking about,, you can look at the various portable bluetooth boombox speaker out there from JBL, Bose etc. The design approach they used is because of that reason.
50Hz on a 3 inch is a subwoofer. You can buy a subwoofer module to do this. Something like this. I have a pair and it really works well, but it jumps all over the place.
https://www.parts-express.com/Tang-Band-T3-2190S-3-Subwoofer-Module-7-1-2-x-3-5-8-264-942
3) From a marketing perspective, what you ask is very nice and I am sure many people out there, but you are not the only marketing genius out there. If it was easily achievable, there would be a whole bunch of PC speakers that fit this description from many established PC accesories speaker makers out there. There is a reason why products like this don't exist. And BTW, that subwoofer module is not the answer for PC speaker, there is so much vibration that it bounces all over the place everytime bass is played. It literally fell of the table one time from all the vibration and jumping around.
4) One more thing, what was mentioned about crest Factor is very important. When you say, I want the singing voice to be 80 dB means the kick drum is 92db.
5) If you boosted something by 20db, that means the power you are putting is 100X higher. so if you are listening to your vocals at 1 W, your bass is coming in at 100W, if they are of the same level, but if you consider that the level of kick drum is higher than the singing voice by 12db. You would need about 1000W.
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k'n'h, this all seem to be told many times but all you read is dick-waving? Well, rocky road ahead, you are asking for help and people are trying to help but you are not listening. You are just waiting some one tells you the fantasy you want to hear, all else is false, right? There is not many on this forum I think tell you that, you could try some other.
Honestly, just build the small speakers for aesthetics you want. People are so used to distorted it doesn't matter if the numbers you came up with cannot be reached. Pencil on the back plate that it plays 50Hz with 30db boost and live happy ever after 😀 The numbers are not important, the sound is and you really could just like it even if it didn't reach the numbers you are trying to reach.
ps.
Some thought experiments: why would live concert speaker rigs be big and bulky and expensive if small speakers would make it just fine, just buy better EQ to boost more? Or, can you hear the small speaker you described playing kick drum in your room in your toilet for example? If they really played 50Hz you would hear it quite well. Like a live concert, the bass really is there and is heard quite far a way, behind buildings, even inside houses. Its the same physics in your home, in our homes, on the planet, as long as the atmospheric composition and temperature stays favorable. Your system can be scaled down from live rig of course, as it is listened quite close by, but not too small.
Honestly, just build the small speakers for aesthetics you want. People are so used to distorted it doesn't matter if the numbers you came up with cannot be reached. Pencil on the back plate that it plays 50Hz with 30db boost and live happy ever after 😀 The numbers are not important, the sound is and you really could just like it even if it didn't reach the numbers you are trying to reach.
ps.
Some thought experiments: why would live concert speaker rigs be big and bulky and expensive if small speakers would make it just fine, just buy better EQ to boost more? Or, can you hear the small speaker you described playing kick drum in your room in your toilet for example? If they really played 50Hz you would hear it quite well. Like a live concert, the bass really is there and is heard quite far a way, behind buildings, even inside houses. Its the same physics in your home, in our homes, on the planet, as long as the atmospheric composition and temperature stays favorable. Your system can be scaled down from live rig of course, as it is listened quite close by, but not too small.
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Muddy is probably a reasonable way to refer to distortion. We're not talking about a pop or crackle sound. Those would likely be something originating in the electronics. We are talking here about the inability of the speaker cone to flex cleanly and deliver an adequate amount of air pressure at low frequencies due to its small size.
Speaker design is a trade off and as much as you would like to achieve your goals for low end performance in a very small cabinet it isn’t going to happen. Look at as many options as you like, but in the end the laws of physics will prevail. Everytime.
If you really want to make progress on this matter then it would be better to either give up trying to reach down to 50Hz or be willing to accept a somewhat larger cabinet.
For a serious design in a still relatively small cabinet you might want to look at these four kits from Meniscus Audio.
Overnight Sensation by Paul Carmody
$112.43
Soprano by Jeff Bagby
$242.69
Stance by Ben “Wolf” Shaffer
$193.36 – $243.56
Speedster by Paul Carmody
$361.34
I’ve been extremely pleased with the Jeff Bagby Piccolos and suspect that the smaller Sopranos can deliver excellent audio performance as well.
Also take a look at the pictures of some of Wolf’s Stance builds on the Internet. The cabinets are very attractive and done in a way that seems to reduce their size visually. Here is a link:
stance speaker kit - Bing images
Was " a 3 watt amp " a mistake ? - that's one reason you'll get muddy bass. If it's 3 watt, it's probably running of a very weak 5 .5 volt power supply, and with 5.5 volt, you'll need a about a farad worth of capacitors to regulate it. If you want to run a load ( and you'll need more tan one ) 3 inch drivers hard, perhaps a 200 watt amp would be better. The only way you'll get decent bass from 3 watt is a Tannoy Westminster, and that has a 15 inch in a MASSIVE horn.
3 watt amplifier is not probably going to blow up the speaker, but it will distort as peaks demand more voltage there is to deliver the peaks get clipped. Yeah most probably not hearing 50Hz, or at least not much, there might be some. There are harmonics from the 50Hz tone created by amplifier/speaker distortion, 100Hz, 150Hz and so on, that you'll hear. In addition kick drums are very rarely single tone but there is content up to many kilohertz, all very audible and crafted to be audible so that people perceive the bass with systems that don't really have bass.
Depends on how you define mud but yes, general poo sound. Pop and crackle are most likely symptoms of something hitting to limits but there is distortion long before. Drivers as electro mechanical devices are analog so there is continuous state between no distortion and crack and pop, not just distorting and not distorting. Even the most advanced drivers of today have only so much "linear" output available around the resting position after which the surround and spider start to have different effect on the cone travel as with the electronic part, voice coil gets further out from the magnet gap and so on. Then all this can be asymmetric, cone goes in there can be different forces in the system as cone travels out. These all generate distortion, properties of the system change as cone has more excursion. I'm not pro on this, but this is the simplification, hopefully helping you to think about how it might play out.
Again not pro on driver spec but it is analog system and not just on-off switch, there is slope to any high or low pass we have. Fs is free air resonance, its natural resonance where the driver moves easily but below this the response likes to drop as more force, more excursion would be needed to maintain the response flat as frequency gets lower. You can do it by increasing the amplifier output (EQ) but this will quickly reach the driver limits, excursion limit and voice coil heats as more power is poured in. As said, if you need to boost the bass 20db it just not going to work out, the driver can't do it physically. Or, it can but distortion rises until at some point magic smoke comes out.
What is boost? It is eventually just more voltage gain at specific frequency. Your amplifier has only so much voltage available on its power supply rails no matter what frequency and this is the ultimate limit how much there is available. All you do boosting the bass 20db is trying to get the amplifier to output more power than it's power supply allows generating more harmonics and muddying the sound. This is of course relative to your volume pot setting(s) which is also voltage gain but this time full bandwidth. If it is already set so that the amplifier outputs half of its capability the EQ will boost only 3db before the amplifier hits the power supply limit, not 20db. It will appear louder though as peaks get clipped out distortion increases and this is apparently louder but it is distorted yeah. You could buy heftier amplifier, if there was say >100V rails on it and output power capability to 8ohm load exceeding 1000W instead of just 3W the small driver would be killed instantly as you tried to put that much power in.
So, imagine you have any power amplifier, million watts, the limit how much you can boost is the capability of the driver, the xmax (or mechanical travel more accurately, x-mech) and heat dissipating capability of the driver. This is directly related to what I wrote earlier, volume displacement. You can directly get the maximum bass output capability from volume displacement, how much air a driver can displace. Back to reality, amplifier has to have enough power to deliver to the driver(s), that could be 10W or 5000W, depends on your driver(s) and what they can handle. Luckily todays amplifiers are cheap and small so we could imagine our amplifier to have million watts as we design our home loudspeaker systems, basically there is no need to limit the speaker design by amplifier output capability, just go online and buy big enough amp. Only limit for low frequency output is the size of the driver, size of the loudspeaker.
Yeah if your driver can handle the amplifier power fed in to make enough displacement to reach 80db at 50Hz. If it is big woofer instead, bigger cone say 15", less excursion is needed for the same displacement, less power is needed, less distortion.
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To quote a song "physics makes us all its bitches".
Since the OP is all about the size the only real choice is to build it and live with how it sounds. If your goal is a spec to play at a certain volume and freq then you need to change your limitations.
Exactly.
k'n'h, there is no problem with the plan as such, only that the numbers / expectations don't quite match with the plan, this is what people have been trying to express. This is just reality, no point to stress about it. Written numbers are very hard to turn into actual system playing (mentally), or turn a playing system into numbers without measuring accurately so it is very hard to get expectations to meet reality without experience.
All the details people have written make this appear dick-waving I see, but the advice is there: just build what you wish and it is about the max performance you get. If it still is poor sound no matter how much you wished it to be good, just dick into the details and build bigger system until result meets expectations, no way around it, no matter the numbers. Besides, the sound might be just fine.
k'n'h, there is no problem with the plan as such, only that the numbers / expectations don't quite match with the plan, this is what people have been trying to express. This is just reality, no point to stress about it. Written numbers are very hard to turn into actual system playing (mentally), or turn a playing system into numbers without measuring accurately so it is very hard to get expectations to meet reality without experience.
All the details people have written make this appear dick-waving I see, but the advice is there: just build what you wish and it is about the max performance you get. If it still is poor sound no matter how much you wished it to be good, just dick into the details and build bigger system until result meets expectations, no way around it, no matter the numbers. Besides, the sound might be just fine.
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"Things went a bit sideways, with a bit of a dick-measuring contest among experts"
"Well unfortunately I did not get an answer I needed for my main question, lets try this a third time and maybe someone can explain this in simple terms without any technical lingo or any links where explanations are also too technical which I do not understand."
"Well unfortunately I did not get an answer I needed for my main question, lets try this a third time and maybe someone can explain this in simple terms without any technical lingo or any links where explanations are also too technical which I do not understand."
k'n'h Perhaps not being rude and obnoxious to the people that are giving you advise would be preferable. Just because you disagree with the advise, does not make them wrong.
my simulation was based on TWO drivers (mounted near eachother). one driver alone will produce 6dB less.
as i said previously you might limit bass extension to around 100 Hz, requiring far less bass equalization.
that would probably be slightly more bass compared to what your existing small speaker has.
i would anyway suggest you build the speaker as you planned (e.g. two eminence drivers in 1,7 liters), listen to it without bass extension and then step by step lower the bass extension limit to see how it sounds and how the speaker behaves.
have a look at rod elliott's linkwitz transform bass extension circuit: https://sound-au.com/project71.htm
Yeah, less EQ boost is a good thing.
One more thought trying to explain the situation:
The thing with EQ bass boost is kind of counter intuitive with small bass drivers as the EQ really doesn't boost the bass, or actually does it by reducing anything above the bass, if the driver just can't handle any extra power. Example, we have a small driver that can take 20W power before the voice coil melts or cone rips off. Now, if there is 20db EQ boost on the bass this practically means the bass frequencies gets the full 20W the driver can tolerate and all above gets 20db less output. EQ does not add bass capability, it only balances out what ever capability there is. To get more capability bigger / more drivers is needed, more volume displacement.
If one tries to put more than 20W into the example driver it just dies. EQ boost is fine if your speaker can handle extra power, like big speakers with big voice coils and advanced cooling motors, but then one wouldn't probably need any EQ boost as the driver was bigger with bigger volume displacement. Bigger is better and small is fine it just doesn't play as loud, or low, or both, no matter what.
Same goes if the power amplifier is "too small", so that the driver could take anything we put into it but if the amplifier can output only 3W and we boost bass 20db the bass gets full tilt 3W but anything above gets much less, in this case 100 times less, 0.03W (simplified).
One more thought trying to explain the situation:
The thing with EQ bass boost is kind of counter intuitive with small bass drivers as the EQ really doesn't boost the bass, or actually does it by reducing anything above the bass, if the driver just can't handle any extra power. Example, we have a small driver that can take 20W power before the voice coil melts or cone rips off. Now, if there is 20db EQ boost on the bass this practically means the bass frequencies gets the full 20W the driver can tolerate and all above gets 20db less output. EQ does not add bass capability, it only balances out what ever capability there is. To get more capability bigger / more drivers is needed, more volume displacement.
If one tries to put more than 20W into the example driver it just dies. EQ boost is fine if your speaker can handle extra power, like big speakers with big voice coils and advanced cooling motors, but then one wouldn't probably need any EQ boost as the driver was bigger with bigger volume displacement. Bigger is better and small is fine it just doesn't play as loud, or low, or both, no matter what.
Same goes if the power amplifier is "too small", so that the driver could take anything we put into it but if the amplifier can output only 3W and we boost bass 20db the bass gets full tilt 3W but anything above gets much less, in this case 100 times less, 0.03W (simplified).
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Ok, lots of good info here, after talking to some people at parts express and combining some info from you guys I’m slowly getting the picture, not fully but enough.
I said from the start I have to pay someone to put it together on the electronics side, so it’s not just built it and see how it works, it’s pay someone see how it works, then pay more see how it works with different drivers… so most likely it will not be a clean system if I want to play around with different drivers and different EQ/ Crossovers.
So it’s either start with cheap DSP and someone will rig it for me, then port it over to analog with fixed values afterwards, or maybe something along these lines:
https://sound-au.com/project148.htm
With additional tone controls, which is not as flexible as DSP and probably not as clean sounding either, then also port it over to fixed value analog.
Last issue to resolve, can we please go back to Dunlavy SM-1 crossover. Can anyone tell or at least estimate what type of set up is it.
I’ve looked at typical passive 2-way or 3-way crossovers, they do not have as many coils, so my gut feeling he is not running both drivers together up to the tweeter and then simply crosses them, perhaps it’s something similar to my attempt of 2.5-way maybe different crossover points then what I want to do and no gain on low end or maybe he cut off the high and mid range to match the low end as well.
What can we extract from that picture.
I don’t care if it relates to my case or not, the logic is still the same, either cut everything down to the level of the low end and see how loud it is and how much color is there or slightly boost the low end till it’s max excursion.
Cheers
I said from the start I have to pay someone to put it together on the electronics side, so it’s not just built it and see how it works, it’s pay someone see how it works, then pay more see how it works with different drivers… so most likely it will not be a clean system if I want to play around with different drivers and different EQ/ Crossovers.
So it’s either start with cheap DSP and someone will rig it for me, then port it over to analog with fixed values afterwards, or maybe something along these lines:
https://sound-au.com/project148.htm
With additional tone controls, which is not as flexible as DSP and probably not as clean sounding either, then also port it over to fixed value analog.
Last issue to resolve, can we please go back to Dunlavy SM-1 crossover. Can anyone tell or at least estimate what type of set up is it.
I’ve looked at typical passive 2-way or 3-way crossovers, they do not have as many coils, so my gut feeling he is not running both drivers together up to the tweeter and then simply crosses them, perhaps it’s something similar to my attempt of 2.5-way maybe different crossover points then what I want to do and no gain on low end or maybe he cut off the high and mid range to match the low end as well.
What can we extract from that picture.
I don’t care if it relates to my case or not, the logic is still the same, either cut everything down to the level of the low end and see how loud it is and how much color is there or slightly boost the low end till it’s max excursion.
Cheers
