Sreten needs to update his 14 links treatment , a few of those are broken ...
So System7, you are saying that the driver's LE has to be equal to or less than the series choke in a 2nd order lowpass right? How much shunt resistance is required to knock down the ringing and peaking? If the required shunt resistance is too low then i totally get what your saying, i could see how the whole idea would become pointless...... However the use of a light zobel following the filter could work, meaning a zobel with a smallish value cap because we only need to damp a peak thats placed pretty high in frequency right? 5k? 6k? .... just an idea ... Anyway, System7 what software do you use for crossover simulation? that looks like something i could have fun playing with ...
By the way, not to offend anyone, or be a contrarian dick and not to "rain on the parade" of all of the full ranger audiophile guys and others who use BSC (because i say this out of playfulness and lightheartedness) but isn't "baffle step bass boost" sort of a misnomer and BSC is just a nicer nearly candycoated way of saying attenuated highs and mids? Maybe it should be renamed to "knocking down the mids & highs so the bass appears to sound louder but its really not because its a only a relative thing" which abbreviated would be: KDTM&HSTBATSLBIRNBIOART ....... Ok , I admit that it is not catchy in the slightest but at least it is honest
While on the subject though, The piggybacked cap & resistor network that i added (in series with the LeSon tweeter) to a sketch earlier in this discussion is sort of like a reverse tilt BSC because it favors the higher notes of a tweeter instead of BSC which favors the low notes of a woofer) , it can also actually flatten the impedance curve a bit by adding a few ohms of series resistance to the lower notes in the tweeter's spectrum .... The tilt effect which favors the high end is not unlike the "Constant Directivity" compensation in the world of PA ...
So System7, you are saying that the driver's LE has to be equal to or less than the series choke in a 2nd order lowpass right? How much shunt resistance is required to knock down the ringing and peaking? If the required shunt resistance is too low then i totally get what your saying, i could see how the whole idea would become pointless...... However the use of a light zobel following the filter could work, meaning a zobel with a smallish value cap because we only need to damp a peak thats placed pretty high in frequency right? 5k? 6k? .... just an idea ... Anyway, System7 what software do you use for crossover simulation? that looks like something i could have fun playing with ...
By the way, not to offend anyone, or be a contrarian dick and not to "rain on the parade" of all of the full ranger audiophile guys and others who use BSC (because i say this out of playfulness and lightheartedness) but isn't "baffle step bass boost" sort of a misnomer and BSC is just a nicer nearly candycoated way of saying attenuated highs and mids? Maybe it should be renamed to "knocking down the mids & highs so the bass appears to sound louder but its really not because its a only a relative thing" which abbreviated would be: KDTM&HSTBATSLBIRNBIOART ....... Ok , I admit that it is not catchy in the slightest but at least it is honest
While on the subject though, The piggybacked cap & resistor network that i added (in series with the LeSon tweeter) to a sketch earlier in this discussion is sort of like a reverse tilt BSC because it favors the higher notes of a tweeter instead of BSC which favors the low notes of a woofer) , it can also actually flatten the impedance curve a bit by adding a few ohms of series resistance to the lower notes in the tweeter's spectrum .... The tilt effect which favors the high end is not unlike the "Constant Directivity" compensation in the world of PA ...
Now here is an idea,
As an alternative (to BSC) Krafty's woofer could be loaded into a Quarter Wave Pipe (aka TL) and get significantly more bass response , the real deal , not cheating and not just "relative" like BSC ....... Higher output would be possible this way, more efficiency, more headroom, and BSC wouldn't be as necessary so a small amount of wattage could produce surprisingly big sound ....
I have used quarter wave loading with lots of high QTS woofers with high FS ratings and I am always impressed with their performance ... The bass response is always far superior to a standard sealed or ported box with the same driver ... They are also very simple boxes to build ...
We built a nice set of 42" QWP towers for a friend recently using Selenium brand 8W4P drivers and got solid response right down to around 60hz (actually a slight bump down at 60hz so i think we could have stuffed the top end of the cabinet a little more to smooth that out) , but they sound fabulous! Nice and warm sounding, full and rich.. They actually sounded ok without a sub... Those same Selenium drivers in a ported box sounded thin , the difference the cabinet made was fully ASTOUNDING
Of course BSC could also be used in conjunction with a QWP if someone wanted their sound to be even richer and fuller but the ones we built sounded pretty damn good with the woofer running dry (no network whatsoever) , we did use a 3rd order high pass on the tweeter though ...
As an alternative (to BSC) Krafty's woofer could be loaded into a Quarter Wave Pipe (aka TL) and get significantly more bass response , the real deal , not cheating and not just "relative" like BSC ....... Higher output would be possible this way, more efficiency, more headroom, and BSC wouldn't be as necessary so a small amount of wattage could produce surprisingly big sound ....
I have used quarter wave loading with lots of high QTS woofers with high FS ratings and I am always impressed with their performance ... The bass response is always far superior to a standard sealed or ported box with the same driver ... They are also very simple boxes to build ...
We built a nice set of 42" QWP towers for a friend recently using Selenium brand 8W4P drivers and got solid response right down to around 60hz (actually a slight bump down at 60hz so i think we could have stuffed the top end of the cabinet a little more to smooth that out) , but they sound fabulous! Nice and warm sounding, full and rich.. They actually sounded ok without a sub... Those same Selenium drivers in a ported box sounded thin , the difference the cabinet made was fully ASTOUNDING
Of course BSC could also be used in conjunction with a QWP if someone wanted their sound to be even richer and fuller but the ones we built sounded pretty damn good with the woofer running dry (no network whatsoever) , we did use a 3rd order high pass on the tweeter though ...
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There is something you guys should check out! While im ranting on the subject of midbass drivers & QWPs i thought i might just throw this out there, I don't know if Mavin delivers to the UK or to Brazil but holy cow they have a good deal on this following MTM kit:Klipsch Foster 5 1/4 inch Center Channel Speaker Kit
22 dollars gets you a nice crossover , two midbass drivers and a tweeter! We are in the process of building two QWPs for these two MTM kits right now, they will be the "mains" in my friend Adam's home theater system. These kits can be used in a QWP almost the exact same size as the one required for the 8W4P .
We received the delivery a few days ago and i cannot believe how nice the crossovers are on these, heavy gauge chokes and all poly caps, the crossovers are worth 22 dollars all by themselves!
I will attach a few pictures that we took of what we received, this is a great deal !
22 dollars gets you a nice crossover , two midbass drivers and a tweeter! We are in the process of building two QWPs for these two MTM kits right now, they will be the "mains" in my friend Adam's home theater system. These kits can be used in a QWP almost the exact same size as the one required for the 8W4P .
We received the delivery a few days ago and i cannot believe how nice the crossovers are on these, heavy gauge chokes and all poly caps, the crossovers are worth 22 dollars all by themselves!
I will attach a few pictures that we took of what we received, this is a great deal !
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The software I use is Visaton Boxsim. You can import projekte files straight into it for an easy introduction. http://boxsim-db.de/standcouplet-wg/
You gradually get the idea of what to do with different drivers. Flattish or even overly lively ones need more work with the filter. Ones that naturally rolloff are kinda easy.
I get quite good at guessing what different drivers need these days. Just from the look of them, the Le and Re, and the Qts for the cabinet, and preferably seeing a frequency plot.
Bafflestep is, of course, midrange rolloff. But that always causes a second question in my experience, which is "How does that make the bass louder?". So I call it bass boost.
You gradually get the idea of what to do with different drivers. Flattish or even overly lively ones need more work with the filter. Ones that naturally rolloff are kinda easy.
I get quite good at guessing what different drivers need these days. Just from the look of them, the Le and Re, and the Qts for the cabinet, and preferably seeing a frequency plot.
Bafflestep is, of course, midrange rolloff. But that always causes a second question in my experience, which is "How does that make the bass louder?". So I call it bass boost.
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I have a quick question...
So I am testing with this old PHILIPS stereo system, from the times these commercial systems sounded good.
If I de-attach the power amplifier from the system, I will be removing the pre-amp that has all the EQ controls (actually 3 controls Bass, Mediums, Treble). My SHARP old one in the living room has 5 EQ controls.
My question is... suppose I de-attach the power amp from the system, and hook it up right in the computer soundcard "out"... AT WHICH LEVELS the EQ will be with no pre-amp.
Can I trust these serigraphs that is written "-10dB 0dB +10dB", can this be trusted? Will the power-amp be at 0dB as if it were with the 0dB pre-amp controls position?
So I am testing with this old PHILIPS stereo system, from the times these commercial systems sounded good.
If I de-attach the power amplifier from the system, I will be removing the pre-amp that has all the EQ controls (actually 3 controls Bass, Mediums, Treble). My SHARP old one in the living room has 5 EQ controls.
My question is... suppose I de-attach the power amp from the system, and hook it up right in the computer soundcard "out"... AT WHICH LEVELS the EQ will be with no pre-amp.
Can I trust these serigraphs that is written "-10dB 0dB +10dB", can this be trusted? Will the power-amp be at 0dB as if it were with the 0dB pre-amp controls position?
I really don't know the answer to that.
My own method, because I know what a good neutral loudspeaker sounds like, is just to play a familiar GOOD CD that I know over the prototype. Dire Straits first album works for me.
I can usually pick out what is wrong. It's surprising that even 2dB in level on a tweeter can unbalance a system. You can also pick out little small peaks when a good vocalist like Diana Krall hits certain notes.
I had a lot of fun with this very simple PC program called SweepGen. I learned that most of the music is coming out below 3kHz from the woofer. The tweeter doesn't actually do much beyond adding an airiness.
Lynn Olson uses pink noise to evaluate a woofer. It's bassier and more representative than white noise. But he has a very trained ear. You can listen to pink and white noise on YouTube.
But Sweepgen is good. You can train your ear to hear "out of phase" and get an idea of what frequencies certain notes actually are. Which is useful if your speaker is "Coloured" and emphasises certain tones. If you have a headphone jack to phono adaptor, you can hook it up to your HiFi.
My own method, because I know what a good neutral loudspeaker sounds like, is just to play a familiar GOOD CD that I know over the prototype. Dire Straits first album works for me.
I can usually pick out what is wrong. It's surprising that even 2dB in level on a tweeter can unbalance a system. You can also pick out little small peaks when a good vocalist like Diana Krall hits certain notes.
I had a lot of fun with this very simple PC program called SweepGen. I learned that most of the music is coming out below 3kHz from the woofer. The tweeter doesn't actually do much beyond adding an airiness.
Lynn Olson uses pink noise to evaluate a woofer. It's bassier and more representative than white noise. But he has a very trained ear. You can listen to pink and white noise on YouTube.
But Sweepgen is good. You can train your ear to hear "out of phase" and get an idea of what frequencies certain notes actually are. Which is useful if your speaker is "Coloured" and emphasises certain tones. If you have a headphone jack to phono adaptor, you can hook it up to your HiFi.
Krafty ,
Bypassing the pre-amp and it's eq controls is definitely not a bad idea, simplifying means there is less to go wrong .. Those old analog tone and EQ controls weren't necessarily perfect or precise either ...
Thank you System7 , i will have to give Boxsim a try! Sweepgen looks pretty cool too, i might have to grab that ....
I usually do sweeps and measurements with TrueRTA, but i plan on giving HOLMimpulse a shot here soon ...
Bypassing the pre-amp and it's eq controls is definitely not a bad idea, simplifying means there is less to go wrong
.. Those old analog tone and EQ controls weren't necessarily perfect or precise either ... Thank you System7 , i will have to give Boxsim a try!
Sweepgen looks pretty cool too, i might have to grab that ....I usually do sweeps and measurements with TrueRTA, but i plan on giving HOLMimpulse a shot here soon ...
Ooh, I've just realised that SweepGen has added pink noise! Must get the latest version.
Not that I have any idea what pink noise really means. Unlike some people, I admit to not knowing everything. Speakers still baffle me really. I've never heard or built a perfect one. Measurement be darned, it's all about your ears being happy.
Matthew, your new MTM looks fun. That's a clone of the famous Audax mylar balanced dome tweeter there. It's not bad at all.
Above is the best mylar tweeter I have ever heard. It's a Sony jobbie in my Sony E44 build. It's actually sensational for a cheapie.
Not that I have any idea what pink noise really means. Unlike some people, I admit to not knowing everything. Speakers still baffle me really. I've never heard or built a perfect one. Measurement be darned, it's all about your ears being happy.
Matthew, your new MTM looks fun. That's a clone of the famous Audax mylar balanced dome tweeter there. It's not bad at all.
An externally hosted image should be here but it was not working when we last tested it.
Above is the best mylar tweeter I have ever heard. It's a Sony jobbie in my Sony E44 build. It's actually sensational for a cheapie.
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Hi,
So we are 17 pages into talking about a pair
of speakers to go in the back shelf of car ?
Good grief.... Talk about complicating things.
The links treatment is basically sometimes
you have to work it out for yourself, and
generally learning stuff helps sorting the
wheat from the chaff, keeping it simple.
It does not imply a lost cause ... that is
those who just want spoon feeding.
Here presumably all you need is an L-pad
on the tweeter and a 1st order series x/o,
no zobel on the bassmid, around 5KHz
is my best ~ guess, without simulation.
In a car there is not much point complicating things
too much compared to seeing what works IMO.
rgds, sreten.
So we are 17 pages into talking about a pair
of speakers to go in the back shelf of car ?
Good grief.... Talk about complicating things.
The links treatment is basically sometimes
you have to work it out for yourself, and
generally learning stuff helps sorting the
wheat from the chaff, keeping it simple.
It does not imply a lost cause ... that is
those who just want spoon feeding.
Here presumably all you need is an L-pad
on the tweeter and a 1st order series x/o,
no zobel on the bassmid, around 5KHz
is my best ~ guess, without simulation.
In a car there is not much point complicating things
too much compared to seeing what works IMO.
rgds, sreten.
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Hi,
Even though people here could have ridiculed themselves in your opinion,
you are walking on the same path, because this is not like what you're saying.
This is not a car project. I already showed the enclosure that said speaker is in.
And below is the amp I am talking about.
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Krafty ,
There is always the risk of of damage to the amp or shortening it's lifespan if you are driving a lower impedance load than the amp is rated for , however you can often (but not always) tell if the amp isn't handling the 4 ohm load because there will audible distortion, the bass will sound sloppy or undefined, or the amp will overheat and or go into protect mode especially at high volume levels ..... If none of those things are happening and you aren't noticing any signs of strain then i wouldn't really worry about it too much , but there are no guarantees when you are running a device like an amp outside of it's specs ..... With that said i have gotten away with it many times
There is always the risk of of damage to the amp or shortening it's lifespan if you are driving a lower impedance load than the amp is rated for , however you can often (but not always) tell if the amp isn't handling the 4 ohm load because there will audible distortion, the bass will sound sloppy or undefined, or the amp will overheat and or go into protect mode especially at high volume levels ..... If none of those things are happening and you aren't noticing any signs of strain then i wouldn't really worry about it too much , but there are no guarantees when you are running a device like an amp outside of it's specs ..... With that said i have gotten away with it many times
System7
The Samsung tweet that comes with the Mavin kit is based on an Audax design you say? Very cool .... It does have very good tone, and it is fairly efficient (95db @1w 1m) , surprising for such a dinky thing ..... Its a potent little guy ..... The Klipsch midwoofs that come with the kit seem pretty good too, they produce great midrange very clear and balanced and seem to have a few mm of usable excursion, wont be sure about how the midbass sounds until we get them loaded into the cabinet but the hornresponse sims do look excellent ....
and Pink noise , its a useful feature! has more bass energy than white noise and can be used as an alternative to sweeps when measuring rooms and speakers systems and such ..
What is pink noise? - Definition from WhatIs.com
The Samsung tweet that comes with the Mavin kit is based on an Audax design you say? Very cool .... It does have very good tone, and it is fairly efficient (95db @1w 1m) , surprising for such a dinky thing ..... Its a potent little guy ..... The Klipsch midwoofs that come with the kit seem pretty good too, they produce great midrange very clear and balanced and seem to have a few mm of usable excursion, wont be sure about how the midbass sounds until we get them loaded into the cabinet but the hornresponse sims do look excellent ....
and Pink noise , its a useful feature! has more bass energy than white noise and can be used as an alternative to sweeps when measuring rooms and speakers systems and such ..
What is pink noise? - Definition from WhatIs.com
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I do have to agree on Sreten's policy to keep things simple .... Maybe 18 pages is a bit excessive to discuss such a simple speaker system? Perhaps, but Krafty made progress and i enjoyed the discussion so it was worth it ....
I originally got involved to help him with his LeSon driver, which is an odd bird compared to most piezos that people are familiar with so i could see that the advice he was going to be given would be wrong because most folks would not realize that Krafty has transformer driven piezos....
I originally got involved to help him with his LeSon driver, which is an odd bird compared to most piezos that people are familiar with so i could see that the advice he was going to be given would be wrong because most folks would not realize that Krafty has transformer driven piezos....
Krafty, I hope you reconsider. Because I have to be careful what I say, just let's say never let anyone put you off playing your own game...
I'd like to sum up a couple of issues here. Firstly, bafflestep correction would be an unwanted layer of complexity here. The only sensible way to do it with a high crossover is like this:
Loudspeaker Diffraction Loss and Baffle Step Compensation Circuits
That approach needs a biggish 1.5mH BSC coil and the shunt capacitor in your 0.11mH plus Zobel circuit changes in size due to the 4.7R resistance from the bafflestep section. Hardly worth it.
The impedance problem is not a showstopper. You can convert to an 8 ohm MTM style easily enough and build a centre speaker. I give the conversion below. You double the coil and resistor, and halve the capacitor.
I did build a speaker with two 4 ohm car speakers wired in series many years ago, and it was really rather good. It had something. It's the PA sound.
I've enjoyed learning about piezo tweeters. You've done good work on a budget. Well done. Enjoyed chatting with Matthew too. Another enthusiast.
I'd like to sum up a couple of issues here. Firstly, bafflestep correction would be an unwanted layer of complexity here. The only sensible way to do it with a high crossover is like this:
Loudspeaker Diffraction Loss and Baffle Step Compensation Circuits
That approach needs a biggish 1.5mH BSC coil and the shunt capacitor in your 0.11mH plus Zobel circuit changes in size due to the 4.7R resistance from the bafflestep section. Hardly worth it.
An externally hosted image should be here but it was not working when we last tested it.
The impedance problem is not a showstopper. You can convert to an 8 ohm MTM style easily enough and build a centre speaker. I give the conversion below. You double the coil and resistor, and halve the capacitor.
I did build a speaker with two 4 ohm car speakers wired in series many years ago, and it was really rather good. It had something. It's the PA sound.
I've enjoyed learning about piezo tweeters. You've done good work on a budget. Well done. Enjoyed chatting with Matthew too. Another enthusiast.
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