It's been diskussed before but I'm not finding an answer to my thoughts?
A dynamic woofer dipol line array is supposedly the best match for a ESL panel concerning acoustic signature.
I was all fired up and ready to go... Then I heard a ribbon + H-frame with 3x15" woofers per side (i.e. 3 woofers per channel as in L/R channel) and no slam what so ever. 😱
Hello! 6 15" woofers and no "ka-duff" in the chest? No kick what so ever?
So, I have to ask you guys... Is this always so with dipol bass?
How do you get that slam from a dipol? Is it even possible?
I'll choose a solid physical experience over seamless integration any day if I have to choose. However, I'd rather not have to choose. I want it all!
Is there a way to achieve both?
I'm sorry if you feel this has been discussed ad nauseum before but I'm trying to figure this out and to me it looks like dipol lovers doesn't care about the physical experience because no-one is actually talking about it? It's all about "how clean" the bass is and so on.
I'm not here to step on any toes but I'd really love to know?
A dynamic woofer dipol line array is supposedly the best match for a ESL panel concerning acoustic signature.
I was all fired up and ready to go... Then I heard a ribbon + H-frame with 3x15" woofers per side (i.e. 3 woofers per channel as in L/R channel) and no slam what so ever. 😱
Hello! 6 15" woofers and no "ka-duff" in the chest? No kick what so ever?
So, I have to ask you guys... Is this always so with dipol bass?
How do you get that slam from a dipol? Is it even possible?
I'll choose a solid physical experience over seamless integration any day if I have to choose. However, I'd rather not have to choose. I want it all!
Is there a way to achieve both?
I'm sorry if you feel this has been discussed ad nauseum before but I'm trying to figure this out and to me it looks like dipol lovers doesn't care about the physical experience because no-one is actually talking about it? It's all about "how clean" the bass is and so on.
I'm not here to step on any toes but I'd really love to know?
With dipole it's also a question of the acoustic path difference (D). How wide and deep was the H-frame you heard?
I have 4x18 inch wooders per side in a 2m/6,7ft tall U-frame with 36cm/14inch deep frames. D is approx 70cm, similar to 140cm wide normal baffle or 70cm deep H-frame. I definitely find no lack of slam, but of course it would be a different beast if all drivers were put in enclosures.
I have 4x18 inch wooders per side in a 2m/6,7ft tall U-frame with 36cm/14inch deep frames. D is approx 70cm, similar to 140cm wide normal baffle or 70cm deep H-frame. I definitely find no lack of slam, but of course it would be a different beast if all drivers were put in enclosures.
I don't have the exact measurements but I can give you a guesstimate?
150x50x20 (HxWxD) [cm] Naturally the depth is specified for one cavity the total box depth would be 40cm or so? I might be underestimating the depth though, it could just as well be 2x25cm? (My memory isn't all that it should be.)
150x50x20 (HxWxD) [cm] Naturally the depth is specified for one cavity the total box depth would be 40cm or so? I might be underestimating the depth though, it could just as well be 2x25cm? (My memory isn't all that it should be.)
All the bass slam one could want
Martin Logan Summits (woofers disconnected) along side
of Magneplanar Tympani IV bass (modified) provide tremendous
bass slam. The Magneplanar bass panels have (1254 sq. inches
of surface area) that reproduce bass that is powerful, well
controlled and the transient response is awesome. Also room
acoustics play a very big role in getting great bass. Electrostatic
dipoles with a planar magnetic speaker like the Magneplanar
Tympanis are a match made for each other. They are both
light in mass, have dipole radiation, no box colorations, and
provide a huge sound-stage and great imaging.
A great recording for bass that is very powerful and quick is
Yim Hok-man (Poems of Thunder) Naxos World CD-76002-2
Martin Logan Summits (woofers disconnected) along side
of Magneplanar Tympani IV bass (modified) provide tremendous
bass slam. The Magneplanar bass panels have (1254 sq. inches
of surface area) that reproduce bass that is powerful, well
controlled and the transient response is awesome. Also room
acoustics play a very big role in getting great bass. Electrostatic
dipoles with a planar magnetic speaker like the Magneplanar
Tympanis are a match made for each other. They are both
light in mass, have dipole radiation, no box colorations, and
provide a huge sound-stage and great imaging.
A great recording for bass that is very powerful and quick is
Yim Hok-man (Poems of Thunder) Naxos World CD-76002-2
Attachments
markusA: -Consider the room they played in, it was 6-8 times bigger than a normal room in a home!
That system in a normal living room has "brown note potential". 😉
My system measures good output down to 35-40Hz in my 30m^2 living room - in Gothenbourg the room just sucked up all bass output!
Roger
That system in a normal living room has "brown note potential". 😉
My system measures good output down to 35-40Hz in my 30m^2 living room - in Gothenbourg the room just sucked up all bass output!
Roger
SM7UYJ> I hear you, the rooms were/are terrible. It's just that every time I hear a dipole bass it's the same story, well articulated but no punch. I thought that set-up would be THE ONE to once and for all prove that dipole bass rock. I'd love to hear it in a better room but I don't know anyone with such beasts?
Loved your panels though, too bad you were having trouble with arcing.
avraudio>Interesting match. 🙂
I listened to the CLX just this week and felt the bass was lacking.
It's great to hear that my impressions were wrong, I just wish I could listen to a good system before spending the $$$. It's such a nerve wrecking place to be.
"People on the internet says it's great... let's spend $1000-$2000 to find out."
So, now that we have established I was wrong. 😀
(Yes, it's one of those rare occations where being wrong is a good thing.)
What will I need to get that solid "ka-duff" in the chest?
Loved your panels though, too bad you were having trouble with arcing.
avraudio>Interesting match. 🙂
I listened to the CLX just this week and felt the bass was lacking.
It's great to hear that my impressions were wrong, I just wish I could listen to a good system before spending the $$$. It's such a nerve wrecking place to be.
"People on the internet says it's great... let's spend $1000-$2000 to find out."
So, now that we have established I was wrong. 😀
(Yes, it's one of those rare occations where being wrong is a good thing.)
What will I need to get that solid "ka-duff" in the chest?
With my system all DIY, underfloor loaded at the front, IB's on the sides, and bailey transmission lines at the rear. Playing the DVD of the film contact, the bass was awesome .The floorboards moved thro' your feet.But I couldn't continue playing at this volume because the neighbours complained about plates moving on their shelves. This in a room 13' x 16'. I also use 13 DIY full range planar speakers in the same room with my new AV Receiver. 9 of them 60 x 40 cms using neos. 2 4' x 2' using ferrites and 2 2' x 2' using ferrites. The small neo ones are hanging from the ceiling and the other 4 are on the floor at the front. The bass is clean and tight and goes down to 20 Hz. I daren't turn the volume up too much because of the neighbours. I will have to win the lottery and move house to do so!! Wish me luck.
I would have to win the lottery just to get what you have Henry. To keep things real I'm aiming for a traditional 2-way setup, possibly a sub as well.
Since I'm building a hybrid ESL I expect the X-over to happen somewhere in the 300Hz vicinity.
As we're talking dipole bass now I have a finite number of options, IB, OB, U- or H- frame or maybe a ripole?
IB is not an option, nor does OB seem too likely.
Ripole, U- and H- frames can be made to fit a living room so these will probably be my options unless I'm forgetting something? Let's save the planar bass for later. 😉
Any suggestions on the minimum requirements to get the slam I'm talking about?
1x15" woofer or 4x18"? Maybe a 6x6.5" or 6x8" line array?
Since I started the thread doubting it was possible in the first place I really have no clue what I need to make it happen?
Since I'm building a hybrid ESL I expect the X-over to happen somewhere in the 300Hz vicinity.
As we're talking dipole bass now I have a finite number of options, IB, OB, U- or H- frame or maybe a ripole?
IB is not an option, nor does OB seem too likely.
Ripole, U- and H- frames can be made to fit a living room so these will probably be my options unless I'm forgetting something? Let's save the planar bass for later. 😉
Any suggestions on the minimum requirements to get the slam I'm talking about?
1x15" woofer or 4x18"? Maybe a 6x6.5" or 6x8" line array?
Since I started the thread doubting it was possible in the first place I really have no clue what I need to make it happen?
This is some thing that I plan on experimenting with through the summer.
I have 6 x 8" radio shack subs left that are in working order.
I simulated a 3 driver ported cabinet with an electronic assisted filter in Winlsd.
It shows that with the two cabinets should produced inexcess of 115db to 118db.
It is designed with a minimal grouped delay so they should be quite punchy and not muddy and flat down to 25hz.
I will also try an H-Dipole configuration aswell to compare to using a box of the same dimensions of 20" to 24" deep.
Right now I have box already cut that will fit 2 drivers so that is where I will start.
Right now my setup produces that punch quite well as it has alot of surface area and is using the corners of the room has a type of horn system with 2 10" drivers facing into the corner.
So far I have 4 X 10's ,4 X 12's and 2 X 8's ,the system is ruler flat from 1200hz down 20hz with a slight hump at 35hz.
All Running off of one crown dc300a ,it is under powered as the crown is the only good amp that I have running at the moment,but, it does rock!
All of the tweeters and midranges are blown so all of the highs come from the little cabinets on top in the picture.
So the imaging is quite smeared until I get the esl's back up and running.
Back in the day I had a U-frame with 6 X 6.5" with RS polypropelene drivers that sat on top of 3.5' tall cabinet that had a 18" RS sub in it that was my bass guitar rig.
That system was very punchy and it felt like some one just decked you when you hit the all of the strings at once.
That 6 X 6.5" was incredible and I'm sure that because it sitting up high rather than on the floor ,had alot to do with it, as it coupled to the room very well as does my current system.
Not to mention that it held its own during outside gigs as it was quite loud.
A ran it with an Ampeg V4-B and a Sunn concert slave amp,again alot of power.
Anyway I hope that gives you some kind of idea of how to get that slam.
I will find out soon how it is going to be with the esl's.
I'm sure that I probably won't get that full dipole sound as this room is to narrow.
I have already found that out with my appoge's ,but at least I will get that awsome slam that you are seeking ,aswell as, the super clarity from 300hz on up as we pretty much have the same goals.
Cheers! jer
I have 6 x 8" radio shack subs left that are in working order.
I simulated a 3 driver ported cabinet with an electronic assisted filter in Winlsd.
It shows that with the two cabinets should produced inexcess of 115db to 118db.
It is designed with a minimal grouped delay so they should be quite punchy and not muddy and flat down to 25hz.
I will also try an H-Dipole configuration aswell to compare to using a box of the same dimensions of 20" to 24" deep.
Right now I have box already cut that will fit 2 drivers so that is where I will start.
Right now my setup produces that punch quite well as it has alot of surface area and is using the corners of the room has a type of horn system with 2 10" drivers facing into the corner.
So far I have 4 X 10's ,4 X 12's and 2 X 8's ,the system is ruler flat from 1200hz down 20hz with a slight hump at 35hz.
All Running off of one crown dc300a ,it is under powered as the crown is the only good amp that I have running at the moment,but, it does rock!
All of the tweeters and midranges are blown so all of the highs come from the little cabinets on top in the picture.
So the imaging is quite smeared until I get the esl's back up and running.
Back in the day I had a U-frame with 6 X 6.5" with RS polypropelene drivers that sat on top of 3.5' tall cabinet that had a 18" RS sub in it that was my bass guitar rig.
That system was very punchy and it felt like some one just decked you when you hit the all of the strings at once.
That 6 X 6.5" was incredible and I'm sure that because it sitting up high rather than on the floor ,had alot to do with it, as it coupled to the room very well as does my current system.
Not to mention that it held its own during outside gigs as it was quite loud.
A ran it with an Ampeg V4-B and a Sunn concert slave amp,again alot of power.
Anyway I hope that gives you some kind of idea of how to get that slam.
I will find out soon how it is going to be with the esl's.
I'm sure that I probably won't get that full dipole sound as this room is to narrow.
I have already found that out with my appoge's ,but at least I will get that awsome slam that you are seeking ,aswell as, the super clarity from 300hz on up as we pretty much have the same goals.
Cheers! jer
Attachments
Please tell me more about the 6x6.5" U-frame? I've seen Calvin using that setup in one of his builds.
At what frequency did you cross with the 18"?
I'm pretty bad with names and I'm not familiar with the RS speakers you mention, are they pro drivers or what?
What kind of sub was the 18", a dipole as well?
Please keep us updated with you summer experiments as well. 🙂
Your big system sounds like massive overkill but I always say "if it's worth doing, it's worth overdoing."
I think it was some famous musician that came up with it in the first place?
At what frequency did you cross with the 18"?
I'm pretty bad with names and I'm not familiar with the RS speakers you mention, are they pro drivers or what?
What kind of sub was the 18", a dipole as well?
Please keep us updated with you summer experiments as well. 🙂
Your big system sounds like massive overkill but I always say "if it's worth doing, it's worth overdoing."
I think it was some famous musician that came up with it in the first place?
The format was in 2 x 3 configuration and here is A link to a more detail description to save me from retyping everything,
http://www.diyaudio.com/forums/musi...aker-reproduce-piano-sound-3.html#post2551364
and also here is a picture of the 18" ported cabinet.
I will try to dig up the data sheets of the drivers and give more details shortly.
The 6.5" 's were not the pro version as they didn't come out until I had already bought the drivers as they were already quite costly.
I was going to build another setup but my brandnew 18" got stolen and the Radio Shack had quit supplying them aswell as the rest of thier drivers.
The 8" subs that I have are the pro version (PRO-CSW800) and I bought as many of them I could find for $15 a peice when they dumped them aswell.
I almost ended up with 16 of them but I only got 8.
I burn't one of them by mistake and one I dropped when I got it and bent the frame,OOOPS!
For the money I paid I was very impressed at the performance out of a little 8" speaker.
jer
http://www.diyaudio.com/forums/musi...aker-reproduce-piano-sound-3.html#post2551364
and also here is a picture of the 18" ported cabinet.
I will try to dig up the data sheets of the drivers and give more details shortly.
The 6.5" 's were not the pro version as they didn't come out until I had already bought the drivers as they were already quite costly.
I was going to build another setup but my brandnew 18" got stolen and the Radio Shack had quit supplying them aswell as the rest of thier drivers.
The 8" subs that I have are the pro version (PRO-CSW800) and I bought as many of them I could find for $15 a peice when they dumped them aswell.
I almost ended up with 16 of them but I only got 8.
I burn't one of them by mistake and one I dropped when I got it and bent the frame,OOOPS!
For the money I paid I was very impressed at the performance out of a little 8" speaker.
jer
Attachments
Hi,
the dipole will probabely never give You the desired -or used to- slam in the lowest two octaves. It´s just contour and precision but no slam. You can probabely live with this in rooms of less than 25m² area size. In rooms with larger floor space you certainly will always miss on something or the membrane area of the dipole rises to rather non-practical dimensions.
Things change in the kickbass-region ~60-100Hz. Here a dipole can offer outstanding attack, with multiples of smaller drivers improving matters.
That´s why I chose to x-over my big system around 50Hz and augment the dipole bass towers with a dedicated CB-Subwoofer, that just adds the slam to the two lowest octaves. Working below the room´s Schroeder-frequency the sub just pressurizes the room but doesn´t excite the room modes. So no loss in precision but the combination of the dipole´s exactness and the CB´s powerful slam. Working only in a very low frequency range the sub takes advantage of the room-gain, giving high efficiency. So a comparably small Sub will be sufficient, which helps to reduce the overall size of the system.
Keeping low freqs off of the dipole helps in reducing excursion demands, increases efficiency (above a certain transit-frequency the dipole is more efficient than the direct radiating monopole) and helps reducing size.
jauu
Calvin
the dipole will probabely never give You the desired -or used to- slam in the lowest two octaves. It´s just contour and precision but no slam. You can probabely live with this in rooms of less than 25m² area size. In rooms with larger floor space you certainly will always miss on something or the membrane area of the dipole rises to rather non-practical dimensions.
Things change in the kickbass-region ~60-100Hz. Here a dipole can offer outstanding attack, with multiples of smaller drivers improving matters.
That´s why I chose to x-over my big system around 50Hz and augment the dipole bass towers with a dedicated CB-Subwoofer, that just adds the slam to the two lowest octaves. Working below the room´s Schroeder-frequency the sub just pressurizes the room but doesn´t excite the room modes. So no loss in precision but the combination of the dipole´s exactness and the CB´s powerful slam. Working only in a very low frequency range the sub takes advantage of the room-gain, giving high efficiency. So a comparably small Sub will be sufficient, which helps to reduce the overall size of the system.
Keeping low freqs off of the dipole helps in reducing excursion demands, increases efficiency (above a certain transit-frequency the dipole is more efficient than the direct radiating monopole) and helps reducing size.
jauu
Calvin
geraldfryjr> It sounds like a sweet build. 🙂
Hi Calvin, thanks for joining in. 🙂
So, the last two ocataves are best handles with a CB sub? (<60-80Hz)
I like simple, simple is awsome...
If I build a 6x6.5" A-frame (or U-frame?), will I get the kick we're talking about?
Adding a sub for the two lowest octaves isn't a problem, I was kind of thinking about doing that anyway.
Hi Calvin, thanks for joining in. 🙂
So, the last two ocataves are best handles with a CB sub? (<60-80Hz)
I like simple, simple is awsome...
If I build a 6x6.5" A-frame (or U-frame?), will I get the kick we're talking about?
Adding a sub for the two lowest octaves isn't a problem, I was kind of thinking about doing that anyway.
Have you tried low-qts pa-woofers (with eq) in a dipole? They have approx. the same motor strenght vs. cone/coil mass ratio than small hifi-woofers. Pa-woofers usually incorporate 4 inch or bigger voice coil, which is (relatively) bigger, vs. the cone area which the coild has to push, compared to small hifi-woofers. Also one good pa-woofer with advanced motor and shorting ring technology has a mightly low inductance of 0,3-0,7mH, which can't be said about an array of small drivers (equal cone area).
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Very good ,Calvin,Thanks!
That was pretty much the effect I was getting with my bass rig.
The 18" had absolutely nothing to offer above 300hz so I never setup a crossover for it. But I did give it its own amp using the sunn as to save all of the power from that big ampeg for the 6's.
The 18" cabinet was tuned very low in the 10hz to 25hz range and I am able to adjust it using 2 slide tunable 4.5" port tubes in a 8 cu ft. box.
It was not very effiecent by any means compared to todays standards but it did provide for some very nice lows and really gave the full effect when it was online.
jer
That was pretty much the effect I was getting with my bass rig.
The 18" had absolutely nothing to offer above 300hz so I never setup a crossover for it. But I did give it its own amp using the sunn as to save all of the power from that big ampeg for the 6's.
The 18" cabinet was tuned very low in the 10hz to 25hz range and I am able to adjust it using 2 slide tunable 4.5" port tubes in a 8 cu ft. box.
It was not very effiecent by any means compared to todays standards but it did provide for some very nice lows and really gave the full effect when it was online.
jer
Hi,
I prefer to use a CB as Sub, because of mainly 1003 reasons.
1) small size and easyness of design
2) with a slightly too small cabinet (Qt~0,8-0,9), the Fb will probabely fall into the range between 40Hz and 60Hz, so You´d be driving the thing basically below resonance where the drop in amplitude response is -12dB/oct. The room gain on the other hand increases roughly by +12dB/oct, which counters the falling response of the sub to a great degree. So well indeed, that any additional equalizing of the Sub´s amplitude response remains within a small well-to-handle range (power- and excursion-wise). Staying below the room modes omits with the need for complicated filtering with notches etc. Basically all filtering required is a reasonable subsonic and a steep lowpass.
3...1003) sound....sound...sound...sound 😀
@legis
I did use several PA-drivers and my experience is that low-Qt-drivers seldomly give pleasing results. The problem is that the low Qt means low SPL at low frequencies, hence massive amounts of equalization to linearize the response. I do like large PA-drivers in dipoles but I´d look for drivers with a Qt of at least 0.35. The nice thing then is, that built into a small sized folded Dipole like the Ripole, the elevated Fs of the driver (say around 35Hz) sinks considerably to maybe 25Hz, but with less need of equing. Since the PA-drivers are built to handle large amounts of power and excursion, You can still drive them hard and loud without risk of destruction. Such drivers usually sound alot more life and kickin than Low-Fs-HiFi-drivers, but miss out on really deep bass. The small dipole adds the missing link, but preserves the kickbass qualities.
Still though the deep bass remains contoured, but no slam. Because of their sheer size such woofers should not play higher than ~100Hz.
The reasons I use a bass tower with multiples of small drivers are
1) to shape the distribution character so that at least +- 1octave around the X-over frequency ESL-Panel and Bass exhibit the same response.
2) to reduce size, hence achive a preferrable optical impresssion and to allow for higher X-over-frequencies. My Bass-towers footprint is considerably smaller than a sheet of DIN-A4 paper (215x145mm), but still puts out outstanding bass down to 50Hz and lower and up to 250Hz.
jauu
Calvin
I prefer to use a CB as Sub, because of mainly 1003 reasons.
1) small size and easyness of design
2) with a slightly too small cabinet (Qt~0,8-0,9), the Fb will probabely fall into the range between 40Hz and 60Hz, so You´d be driving the thing basically below resonance where the drop in amplitude response is -12dB/oct. The room gain on the other hand increases roughly by +12dB/oct, which counters the falling response of the sub to a great degree. So well indeed, that any additional equalizing of the Sub´s amplitude response remains within a small well-to-handle range (power- and excursion-wise). Staying below the room modes omits with the need for complicated filtering with notches etc. Basically all filtering required is a reasonable subsonic and a steep lowpass.
3...1003) sound....sound...sound...sound 😀
@legis
I did use several PA-drivers and my experience is that low-Qt-drivers seldomly give pleasing results. The problem is that the low Qt means low SPL at low frequencies, hence massive amounts of equalization to linearize the response. I do like large PA-drivers in dipoles but I´d look for drivers with a Qt of at least 0.35. The nice thing then is, that built into a small sized folded Dipole like the Ripole, the elevated Fs of the driver (say around 35Hz) sinks considerably to maybe 25Hz, but with less need of equing. Since the PA-drivers are built to handle large amounts of power and excursion, You can still drive them hard and loud without risk of destruction. Such drivers usually sound alot more life and kickin than Low-Fs-HiFi-drivers, but miss out on really deep bass. The small dipole adds the missing link, but preserves the kickbass qualities.
Still though the deep bass remains contoured, but no slam. Because of their sheer size such woofers should not play higher than ~100Hz.
The reasons I use a bass tower with multiples of small drivers are
1) to shape the distribution character so that at least +- 1octave around the X-over frequency ESL-Panel and Bass exhibit the same response.
2) to reduce size, hence achive a preferrable optical impresssion and to allow for higher X-over-frequencies. My Bass-towers footprint is considerably smaller than a sheet of DIN-A4 paper (215x145mm), but still puts out outstanding bass down to 50Hz and lower and up to 250Hz.
jauu
Calvin
I tend to think that low-qts woofers give more accurate and dynamic bass compared to their high-qts counterparts, so investment to bigger amp, that has adequate headroom for equalization, might be a good compromize. (Side note: low inductance might be/is as important regarding the good transient response and bass accuracy) Of course if one wants to drive the woofers with 5w SET, one has to take different approach with the qts. 🙂
Hi,
I agree to a small extent and disagree to a larger.
Theoratically things don´t matter and things should sound the same if the acoustically effektive Q is the same. Typically You aim for a acoustic Q between 0.5 and 1.0. This means that the Fb of a a low Qt-driver rises so high that low bass is basically dampened away and You need loads of electrical equing to correct for the missing bass. The alternative is a driver with higher Qt which then may not need equing at all.
With Dipoles the problem exaggerates since the acoustic phase cancellation hits hard, giving a drop in amplitude response which almost always asks for equing. Looking at the amplitude response of a high Qt driver in a small folded dipole, it may give a rising response with increasing frequency up to the Fb, then tends to level out till the frequency reaches the range of the peak around 150-300Hz and a sharp notch above that peak. The low Qt driver may rise in one nearly linear increasing response up to the peak followed by the notch above. The shape of the curve doesn´t look like a typical known response but more like a sawtooth. To level out and linearize this curvature amounts of equing are needed which are far from healthy. Besides the quick rising power demand -which is not a big deal with modern class-D amps- the driver itself is soon driven into its limits. The result is a considerable loss in dynamic range, over-stressed driver, loads of wasted wattage and imho clearly audible distress signals.
In a dipole I prefer to let the driver simply do what the physics dictate it to do and to use as low equing and power as possible. If I needed more than 6dB of correction I´d look for a different option rather than forcing the system to do something ´it doesn´t want to do´. This asks for drivers with elevated Qt values. I do agree with legis in so far as I prefer rising Qt-values with smaller driver size classes.
jauu
Calvin
I agree to a small extent and disagree to a larger.
Theoratically things don´t matter and things should sound the same if the acoustically effektive Q is the same. Typically You aim for a acoustic Q between 0.5 and 1.0. This means that the Fb of a a low Qt-driver rises so high that low bass is basically dampened away and You need loads of electrical equing to correct for the missing bass. The alternative is a driver with higher Qt which then may not need equing at all.
With Dipoles the problem exaggerates since the acoustic phase cancellation hits hard, giving a drop in amplitude response which almost always asks for equing. Looking at the amplitude response of a high Qt driver in a small folded dipole, it may give a rising response with increasing frequency up to the Fb, then tends to level out till the frequency reaches the range of the peak around 150-300Hz and a sharp notch above that peak. The low Qt driver may rise in one nearly linear increasing response up to the peak followed by the notch above. The shape of the curve doesn´t look like a typical known response but more like a sawtooth. To level out and linearize this curvature amounts of equing are needed which are far from healthy. Besides the quick rising power demand -which is not a big deal with modern class-D amps- the driver itself is soon driven into its limits. The result is a considerable loss in dynamic range, over-stressed driver, loads of wasted wattage and imho clearly audible distress signals.
In a dipole I prefer to let the driver simply do what the physics dictate it to do and to use as low equing and power as possible. If I needed more than 6dB of correction I´d look for a different option rather than forcing the system to do something ´it doesn´t want to do´. This asks for drivers with elevated Qt values. I do agree with legis in so far as I prefer rising Qt-values with smaller driver size classes.
jauu
Calvin
Do you think this driver would be a good candidate for a 6 or 8 driver linearray?
SEAS CA18RLY (H1217)
SEAS CA18RLY (H1217)
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