Transmission Line vs Reflex Ported vs Isobaric

[CnoEvil]

Even though I tried to explain in my last post why I prefer transmission line type speakers I forgot the most important reason and that is the ability to reproduce bass sounds that are directional . Why do people say that bass is not directional :O

Maybe it's "sub bass" that's non directional ie. That covered by the sub.

 

[Al ears]

The problem that I have with the transmission line speakers that I've heard is in the bass timing. There are certain bass frequencies where the bass has lagged behind the rest of the music. It's a smearing of the bass signal, especially on repetitive bass transients. It becomes more of an issue at generous to loud volumes.

If bass timing was a problem I suggest the speakers you heard were not particularly well sorted.

I have never experienced that with ones I have heard or from the ones I currently own.

There is no logical reason why this effect should get worse with increased volume.

 

[oldric_naubhoff]

I think this is because they seem to produce the most life like deep textured bass with real pitch accuracy that does not overwhelm the rest of the music and you can also feel it as well as hear it.

you can always read or hear people praising bass from this or that speaker somewhere along those lines (I especially like "gut wrenching bass" 🙂). can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel? a lightning stoke once some 200m away from me and I couldn't feel anything (I certainly heard A LOT). standing next to decently sized waterfall you'll not feel anything either. well, maybe except for sprinkling water drops. and also full blown philharmonic orchestra during crescendo did never make me feel anything...

to create a wonderful deep and wide stage behind the speakers that can often appear to be many meters deep and wide

this is yet another cliche about some speakers that I don't really understand why some people really crave and rave about. what's realistic about listening to a band and having an impression they are evenly spaced along the length of a tunnel? is this really a life-like impression? if so, I never actually experienced such in real life. I never experienced a feeling that a few people gathered within 1m distance on Z axis seem to be much further behind and in front of each other. they were always exactly where they should be.

sorry Electro. this all seems like critisising you. but it's not my intention. I just used your quotes.

 

[oldric_naubhoff]

Even though I tried to explain in my last post why I prefer transmission line type speakers I forgot the most important reason and that is the ability to reproduce bass sounds that are directional . Why do people say that bass is not directional :O

this is because it's not bass that makes you hear where double bass or percussion bass drum standing but higher in frequency harmonics. CNO pointed out correctly that it's for deep bass frequencies that aren't directorial.

 

[Electro]

I think this is because they seem to produce the most life like deep textured bass with real pitch accuracy that does not overwhelm the rest of the music and you can also feel it as well as hear it.

you can always read or hear people praising bass from this or that speaker somewhere along those lines (I especially like "gut wrenching bass" 🙂). can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel? a lightning stoke once some 200m away from me and I couldn't feel anything (I certainly heard A LOT). standing next to decently sized waterfall you'll not feel anything either. well, maybe except for sprinkling water drops. and also full blown philharmonic orchestra during crescendo did never make me feel anything...

to create a wonderful deep and wide stage behind the speakers that can often appear to be many meters deep and wide

this is yet another cliche about some speakers that I don't really understand why some people really crave and rave about. what's realistic about listening to a band and having an impression they are evenly spaced along the length of a tunnel? is this really a life-like impression? if so, I never actually experienced such in real life. I never experienced a feeling that a few people gathered within 1m distance on Z axis seem to be much further behind and in front of each other. they were always exactly where they should be.

sorry Electro. this all seems like critisising you. but it's not my intention. I just used your quotes.

There is no need to worry I don't take your points of view as any sort of criticism 🙂

I can only think that we both perceive music in very different ways :?

When I go to a live performance or I listen to my HiFi system I can physically feel the music through my body in the form of vibrations that change with pitch and volume , in fact I think if I was to put bungs in my ears so that I was unable to hear the music I could still tell you the title of the song that was being played as long as it was familiar to me .

Next time you listen to music try resting you finger tips lightly on a surface next to you and see if you can feel the vibrations that I speak of . If you can feel them listen to the peak sounds of the music and see if the the music and the vibrations coincide . If they do this is a very basic form of what I am talking about .

I think that some people are completely unable to perceive a stereo image with width and depth .

With some large scale recordings it is like sitting five to ten rows back with the performers on the stage behind the speakers and the music sounds as wide and deep as the physical stage itself . Some other simpler recordings may only have one person on stage performing but it is quite easy to hear the sounds reverberating around the venue giving the impression of a small scale performance in a large space ..

Some recordings give up very little spacial information at all so they sound like the performers are between the speaker with no impression of the space they are playing in , I have found that many recordings on the Naim label are like this .

You mention not being able to feel close lightning strikes , this really shocks and surprises me , close lightning strikes have to be one of the most physical things I have ever felt, the noise seem to vibrate every cell in my body with that initial massive pressure wave followed by the rolling decay of the thunder vibrates the air in my lungs and I find the way the ultra low frequencies bounce and reflect from different structures around the area very pleasurable , I adore the sound and feel of rolling thunder .

I guess it just goes to show how differently each individual person perceives sound . 🙂

 

[CnoEvil]

FWIW. With certain recordings and bass-driven music, with my speakers, I can physically feel the beat.

My sub can pressurise the room to the point I feel ill/queasy....can go to 12 Hz though.

 

[steve_1979]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

You can feel the bass from a kick drum when you listen to a band playing live in a small venue.

 

[CnoEvil]

@David (F.Harvey)

Since you sell all 3 types, would you be prepared to give comment on the differences / characteristics that you've observed, as well as any personal insight / preferences that you have....hope it's not too much of a poisoned chalice; if so, I understand.

Cheers

Cno

 

[lindsayt]

The problem that I have with the transmission line speakers that I've heard is in the bass timing. There are certain bass frequencies where the bass has lagged behind the rest of the music. It's a smearing of the bass signal, especially on repetitive bass transients. It becomes more of an issue at generous to loud volumes.

If bass timing was a problem I suggest the speakers you heard were not particularly well sorted.

I have never experienced that with ones I have heard or from the ones I currently own.

There is no logical reason why this effect should get worse with increased volume.

There's a couple of logical reasons why it's more of an issue with increased volume.

1. Fletcher Munson. http://en.wikipedia.org/wiki/Equal-loudness_contour. At lower volumes our ears are less sensitive to bass than midrange. As the volumes increase our ears get relatively more sensitive to bass. This is the reason that "Loudness" buttons were put on amplifiers once upon a time - to boost bass and treble - they were supposed to be used when listening at lower volumes. With increased volumes any imperfections in bass reproduction become more noticeable due to the Fletcher Munson effect.

2. Greater volumes equals more air chuffing out of the hole in the box of transmission line speakers.

Whether you think bass timing is a problem with transmission line speakers may well depend upon which speakers you've compared them to. As always, sound quality in hi-fi is all relative.

 

[steve_1979]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

Church organs, jet planes, helicopters and drag racing cars produce bass that you can physically feel.

Have you ever heard Concord doing a full throttle take off? When the afterburners come on you can feel the bass go through your whole body.

Or have you ever heard a Vulcan bomber doing a low flyover at an airshow? That plane produces enough bass to set of car alarms!

 

[steve_1979]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

You can sometimes feel a kick in the chest when fireworks explode or when cannons are fired.

I'm not sure if these two can be counted as bass though as they're just single-pulse shockwaves and thus don't have a frequency. :?

 

[oldric_naubhoff]

I can only think that we both perceive music in very different ways :?

When I go to a live performance or I listen to my HiFi system I can physically feel the music through my body in the form of vibrations that change with pitch and volume , in fact I think if I was to put bungs in my ears so that I was unable to hear the music I could still tell you the title of the song that was being played as long as it was familiar to me .

Next time you listen to music try resting you finger tips lightly on a surface next to you and see if you can feel the vibrations that I speak of . If you can feel them listen to the peak sounds of the music and see if the the music and the vibrations coincide . If they do this is a very basic form of what I am talking about .

I think this must be true. the only think that really responds to any air vibration in my case are my eardrums 🙂

I think that some people are completely unable to perceive a stereo image with width and depth .

I don't think this is true. our hearing evolved for eaons and is a means of detecting sound producing object in space. either as a defence or hunting mechanism. everybody, not counting in people with hearing impairment, can easily locate sound objects in space (which direction and roughly far far away) blind-folded. my point in my previous post was that most hi-fi presents acoustic space in a completely artificial way compared to reality.

With some large scale recordings it is like sitting five to ten rows back with the performers on the stage behind the speakers and the music sounds as wide and deep as the physical stage itself . Some other simpler recordings may only have one person on stage performing but it is quite easy to hear the sounds reverberating around the venue giving the impression of a small scale performance in a large space .

if what you're writing is what you get at home then I must commend on quality of your speakers and their ability to reproduce spacial clues (never heard PMCs myself so can't coment). still, I think most speakers create this tunnell-like soundstage that I believe is simply an aberration.

You mention not being able to feel close lightning strikes , this really shocks and surprises me , close lightning strikes have to be one of the most physical things I have ever felt, the noise seem to vibrate every cell in my body with that initial massive pressure wave followed by the rolling decay of the thunder vibrates the air in my lungs and I find the way the ultra low frequencies bounce and reflect from different structures around the area very pleasurable , I adore the sound and feel of rolling thunder .

I too like rumbling of a thunder but it never makes me feel anything. I hear it not feel it. at least I could never feel any sound (especially bass notes) the way many speakers recreate - with this typical tingling sensation in my belly. it's simply about the way speakers excite the air and natural sources. you never get a lot of bass from small sound source. and high frequency source have little enegy.

 

[oldric_naubhoff]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

You can feel the bass from a kick drum when you listen to a band playing live in a small venue.

nope. unless maybe I put my head right into the drum's throat 🙂 but this is a different matter alltogether.

and if I do feel something it's nothing similar to what most speakers make me feel.

 

[oldric_naubhoff]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

You can sometimes feel a kick in the chest when fireworks explode or when cannons are fired.

I'm not sure if these two can be counted as bass though as they're just single-pulse shockwaves and thus don't have a frequency. :?

yes, you're right. it's a shockwave. and as any wave it has frequency. but the difference between sounds natural to our hearing and explosions is the energy (or in other way amount of dB). do you really litsten to music at 140dB+ levels?:O

 

[oldric_naubhoff]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

Church organs, jet planes, helicopters and drag racing cars produce bass that you can physically feel.

Have you ever heard Concord doing a full throttle take off? When the afterburners come on you can feel the bass go through your whole body.

Or have you ever heard a Vulcan bomber doing a low flyover at an airshow? That plane produces enough bass to set of car alarms!

you're really funny Steve. jet planes, helicopters, drag racing cars is all OK, I can't argue with you, you'll definitely feel the impact of passing such car or swirl of the helicopter blade but these are all shockwaves hence at much louder volume levels any music is performed! do you listen to your music at ~160dB and more. does any unamplified music reach that volume levels? if you want to get permanently deaf then be my guest.

church organ, on the other hand, does sound majestic even though it's muuuuch quiter than any of the above. always. but listening to it never gives me the same sensation many speakers give - with this kick in the chest. but I guess it's quite natural. if you take into account the fact that organ bass pipe's throat has much bigger radiating area than a 10"woofer than you should realise that when a small object tries to do a big object's job there has to be some aberrration somewhere. speakers (especially dynamic breed, because they tend to be comparably very small) excite the air in a completely different way than any natural sound source. does any instrument has a pistonic movement-like exciting element? this actually mimics movement of an eardrum but this a receiving element, not exciting.

 

[Anonymous]

Ive never been tempted to buy Isobaric's so I can only comment on TL's, reflex and sealed. My journey into hi-fi started with sealed units such as A&R, Acoustic Research, Goodmans and Wharfedale, primarily for bass quality as I play mainly rock music. I had a pair of Wharfedale E80's back in the 80's which were front ported, and they were superb BUT they needed a big room to produce the fantastic bass they were capable of. After moving house they didnt work in the slightly smaller room they had to go in - I couldnt get any bass at all out of them so I went for Jamo Pro 200 rear ported speakers and they were fantastic, but not as sublime as the Wharfedales but at least the bass was back! Moved house again and the Jamos still sounded great. Decided to upgrade and listened to some great speakers but the one design that caught my ear was the transmission line. I got a pair from IPL, built around a 5" driver and the bass was superb again, almost as good as the huge Wharfedales I had without the room size issues. Ive upgraded again to my present TL's from IPL, built around an 8" driver and Ive not heard anything that comes close to these for amount and quality of bass including everything I heard at the WHF show in Manchester. They dont seem too bothered about position, definitely not as much as any other design Ive had.

To summarise, in my experience sealed units can sound great but seem to produce less bass than other designs, until you get some hefty watts going through them. Also as the volume increases the bass seems to fall away, except for transients. Reflex units seem to do the same but will go to a higher level before this happens. TL's (and this hasnt been asked about, as far as I know) produce bass at a lower volume than anything Ive heard. The smaller units I had did hit a point at which the midrange started to take over, my current ones go to extremely high levels before this happens. All designs have their pro's and con's but for me its the TL's every time.

 

[CnoEvil]

To summarise, in my experience sealed units can sound great but seem to produce less bass than other designs, until you get some hefty watts going through them. Also as the volume increases the bass seems to fall away, except for transients. Reflex units seem to do the same but will go to a higher level before this happens. TL's (and this hasnt been asked about, as far as I know) produce bass at a lower volume than anything Ive heard. The smaller units I had did hit a point at which the midrange started to take over, my current ones go to extremely high levels before this happens. All designs have their pro's and con's but for me its the TL's every time.

Thank you for your comments....I've never heard of IPL.

As with everthing else in hifi (and maybe more so with speakers of this type), implementation is everything, and it's hard to do any of these really well, yet cheaply.

 

[Electro]

I have found this video that gives a simple explanation of the design and advantages of a transmission line speaker.

http://www.youtube.com/watch?v=683FoCDilOE

 

[steve_1979]

You can feel the bass from a kick drum when you listen to a band playing live in a small venue.

nope. unless maybe I put my head right into the drum's throat 🙂 but this is a different matter alltogether.

and if I do feel something it's nothing similar to what most speakers make me feel.

I can definitely feel the bass from a real kick drum. I agree that you usually get more bass from a hifi with big speakers than there is in real life though.

Church organs, jet planes, helicopters and drag racing cars produce bass that you can physically feel.

Have you ever heard Concord doing a full throttle take off? When the afterburners come on you can feel the bass go through your whole body.

Or have you ever heard a Vulcan bomber doing a low flyover at an airshow? That plane produces enough bass to set of car alarms!

you're really funny Steve. jet planes, helicopters, drag racing cars is all OK, I can't argue with you, you'll definitely feel the impact of passing such car or swirl of the helicopter blade but these are all shockwaves hence at much louder volume levels any music is performed! do you listen to your music at ~160dB and more. does any unamplified music reach that volume levels? if you want to get permanently deaf then be my guest.

Jet engines are ridiculously loud when you're standing right next to them but when you're a few thousand feet away they sound much quieter (see inverse-square law). I've heard a Vulcan bomber flying past at a distance of several thousand feet and the noise wasn't excessively loud but I could still feel loads of bass.

I have no idea if this was just deep bass or something to do with shockwaves though?

You can sometimes feel a kick in the chest when fireworks explode or when cannons are fired.

I'm not sure if these two can be counted as bass though as they're just single-pulse shockwaves and thus don't have a frequency.

yes, you're right. it's a shockwave. and as any wave it has frequency.

Yes you're right. Silly me. Of course a shockwave has a frequency.

The frequency of a sound wave is usually measured by counting the number of wave peaks per second. But this is impossible to do with a single-pulse wave as there's only one peak. A single-pulse wave still has a wave-length though, so it's possible to calculate the frequency from this.

 

[oldric_naubhoff]

You can sometimes feel a kick in the chest when fireworks explode or when cannons are fired.

I'm not sure if these two can be counted as bass though as they're just single-pulse shockwaves and thus don't have a frequency.

yes, you're right. it's a shockwave. and as any wave it has frequency.

Yes you're right. Silly me. Of course a shockwave has a frequency.

The frequency of a sound wave is usually measured by counting the number of wave peaks per second. But this is impossible to do with a single-pulse wave as there's only one peak. A single-pulse wave still has a wave-length though, so it's possible to calculate the frequency from this.

don't get too much hanged up on frequency. the power has much more to to with amplitude than frequency of a wave - in other words pressure shift. explosion blast will have very low frequency, something reaching close to DC because there will be one big crest and then one big bottom, followed maybe by some modulation. I think it's even physically impossible for an explosion to have a high frequency.

 

[oldric_naubhoff]

Jet engines are ridiculously loud when you're standing right next to them but when you're a few thousand feet away they sound much quieter (see inverse-square law). I've heard a Vulcan bomber flying past at a distance of several thousand feet and the noise wasn't excessively loud but I could still feel loads of bass.

I have no idea if this was just deep bass or something to do with shockwaves though?

you see, the difference between me and you is that in such a case I hear the roar of a jet engine flying up above me and I don't dilusion myself that I'm feeling something.

 

[steve_1979]

Jet engines are ridiculously loud when you're standing right next to them but when you're a few thousand feet away they sound much quieter (see inverse-square law). I've heard a Vulcan bomber flying past at a distance of several thousand feet and the noise wasn't excessively loud but I could still feel loads of bass.

I have no idea if this was just deep bass or something to do with shockwaves though?

you see, the difference between me and you is that in such a case I hear the roar of a jet engine flying up above me and I don't dilusion myself that I'm feeling something.

I wasn't being delusional. There really was lots of bass.

The Vulcan bomber also set off several car alarms too and I'm pretty sure that they weren't being delusional. 😉

http://www.youtube.com/watch?v=EU1VSCph-G8

 

[oldric_naubhoff]

I wasn't being delusional. There really was lots of bass.

The Vulcan bomber also set off several car alarms too and I'm pretty sure that they weren't being delusional. 😉

http://www.youtube.com/watch?v=EU1VSCph-G8

yeah, that's a nice one. but sometimes you can go past a car and the alarm would start off if the alarm is too sensitively set up.

nevertheless a strong gust of wind would start an alarm too but then we're talking about spls comparable to that of a jet plane flying by, i.e. a hurricane.

my point is at normal spls from noral sound sources sound waves don't have enough energy to excite the body. but speaker cones can. so that means there's something wrong here.

 

[Electro]

Jet engines are ridiculously loud when you're standing right next to them but when you're a few thousand feet away they sound much quieter (see inverse-square law). I've heard a Vulcan bomber flying past at a distance of several thousand feet and the noise wasn't excessively loud but I could still feel loads of bass.

I have no idea if this was just deep bass or something to do with shockwaves though?

you see, the difference between me and you is that in such a case I hear the roar of a jet engine flying up above me and I don't dilusion myself that I'm feeling something.

I think the link below may prove that it is perfectly possible to feel sound through your body .

http://www.theglobeandmail.com/arts/music/dame-evelyn-glennie-the-deaf-percussionist-who-listens-with-her-whole-body/article568725/

I hasten to add that I do not claim to have even a fraction of her wonderful ability .

 

[lindsayt]

can anybody tell me where in the real world, outside your hi-fi set up that is, can I experience bass that I can also feel?

You can feel the bass from a kick drum when you listen to a band playing live in a small venue.

Yep, go to any rock or pop gig in a small indoor venue, or stand near the front in a large venue and you'll get bass that you can feel when the drummer or drum machine or bass guitarist is playing.