Hi everyone!
There's something which has been puzzling me for many years. Euphonic Audio make bass guitar amplifiers and speaker cabs. Their cabs are transmission line designs which are small, efficient and produce deep, extended bass (I once had a shot of their 1x10" coaxial bass combo and can attest to their bass extension).
http://www.eaamps.com/2005/products/cxl112l.htm
For example, here are some of the specs for the CXL112:
19"H x 17"W x 15"D
103dB @ 1m
38Hz to 14kHz
My question is; how do they do it? I'm not sure if the fact that they use TLs helps explain this or make it even more inconceivable. Anyone up for discussing this?
There's something which has been puzzling me for many years. Euphonic Audio make bass guitar amplifiers and speaker cabs. Their cabs are transmission line designs which are small, efficient and produce deep, extended bass (I once had a shot of their 1x10" coaxial bass combo and can attest to their bass extension).
http://www.eaamps.com/2005/products/cxl112l.htm
For example, here are some of the specs for the CXL112:
19"H x 17"W x 15"D
103dB @ 1m
38Hz to 14kHz
My question is; how do they do it? I'm not sure if the fact that they use TLs helps explain this or make it even more inconceivable. Anyone up for discussing this?
Hmmm........
Only true if the box is too big for proper vented in the first place......
🙂/sreten.
Only true if the box is too big for proper vented in the first place......
🙂/sreten.
They are probably tuned to about 60-80Hz, to give you that "punch in the chest" feeling, rather than real low extension.
Hi Pinkmouse.
I have to say that I really don't think that's it. I played my bass through the 1x10" combo with a 1x10" extension cab attached and it sounded way deeper and more solid than (probably) any other cab I'd ever heard. Certainly more so than my previous amp witch had a 15" driver tuned to 40Hz. It wasn't boomy in the slightest.
I have to say that I really don't think that's it. I played my bass through the 1x10" combo with a 1x10" extension cab attached and it sounded way deeper and more solid than (probably) any other cab I'd ever heard. Certainly more so than my previous amp witch had a 15" driver tuned to 40Hz. It wasn't boomy in the slightest.
Ah....of course. You've got to love the guy with the beard!
Now maybe I got the wrong end of the stick, but I was always under the impression that once you started using 8" and 10" drivers and beyond for your transmission lines, the cabinets started to get really really big and that was true for low efficiency hi-fi drivers as well as pro drivers. If that's true, how do they make them so small?
Maybe I should just buy one, measure it and take it apart to see how it's made. Although it would defeat the purpose of figuring out how they're made so that I can make something similar but cheaper because I can't afford their products in the first place.....
Now maybe I got the wrong end of the stick, but I was always under the impression that once you started using 8" and 10" drivers and beyond for your transmission lines, the cabinets started to get really really big and that was true for low efficiency hi-fi drivers as well as pro drivers. If that's true, how do they make them so small?
Maybe I should just buy one, measure it and take it apart to see how it's made. Although it would defeat the purpose of figuring out how they're made so that I can make something similar but cheaper because I can't afford their products in the first place.....
Hi,
You cannot break the laws of physics in an enclosure.
19"H x 17"W x 15"D.......... large for a 1x12" cabinet
103dB @ 1m...................... yeah right......
38Hz to 14kHz................... possibly
🙂/sreten.
You cannot break the laws of physics in an enclosure.
19"H x 17"W x 15"D.......... large for a 1x12" cabinet
103dB @ 1m...................... yeah right......
38Hz to 14kHz................... possibly
🙂/sreten.
That box is almost for sure an aperiodic box, with a partition in it to create a short heavily tapered line... anyone seen a picture of the back?
dave
dave
Hey Dave,
If you're talking about the back of the CXL112, no I haven't. There is a 'vent' at the bottom on the front and I'm reasonably sure that the back just has the connection terminals and L-pad and nothing else.
I'm interested that you think it may be an aperiodic enclosure, mostly because I know so little about them. Can they be modeled in Martin King's Mathcad sheets by increasing the stuffing density and so fourth?
Cheers,
Steve.
If you're talking about the back of the CXL112, no I haven't. There is a 'vent' at the bottom on the front and I'm reasonably sure that the back just has the connection terminals and L-pad and nothing else.
I'm interested that you think it may be an aperiodic enclosure, mostly because I know so little about them. Can they be modeled in Martin King's Mathcad sheets by increasing the stuffing density and so fourth?
Cheers,
Steve.
The picture was kinda dark, i missed that. With that last tidbit, reading between the lines, and the physocal restictions placed by the size of the driver, i think i can do a drawing that will be pretty close to what this box is. The last piece of the puzzle is the driver... i'm busy working but if someone wants to find a candidate driver -- we are looking for a driver with specs as close as possible to this one that is available -- i'm guessing it is an Eminence (likely custom). Having a reference for the size of the driver will give the last physical restraints required to take a stab at reverse engineering it from the available information. Small Vas is something else we are looking for.
dave
dave
Depth Charge said:
What is the big acomplishment here? F3 of 38Hz and topping out at 14k ( most likely with a big gappng hole in the middle ).
Maybe not having any low midrange response exaggerates the amount of bass your hearing😉
Much better results can be had from this box size, and no TL required.
Re: Re: EA: How So Small With Extended Low End
It is a musical instrument speaker... and 103 dB (claimed). I think you will find a challengr to get that low, with that efficiency, in that size a box.
It is a puzzle to solve (or to dispute)
dave
MJL21193 said:
It is a musical instrument speaker... and 103 dB (claimed). I think you will find a challengr to get that low, with that efficiency, in that size a box.
It is a puzzle to solve (or to dispute)
dave
Since I belong to these darn annoying objectivist EEs I'd rather dispute than solve.
Keep in mind that many bass boxes start dropping in the range between 60 hz and 80 Hz (in order to save people's backs !!!) it needs just some trick to achieve a SHALLOWER rolloff than all the others to make one believe that they actually have alower cutoff frequency. I have never heard any of these nor played through one (I neither was tempted to try one so far even though I know the local dealer of them personally).
To be honest I don't like the sound of most commercial bass boxes anyway. Too much of that overcompressed (OK not only the speaker's fault) chest pressurising/headache inducing 100Hz stuff and two little of that belly-pressurising/trousers-flapping 40 to 80 Hz content.
Regards
Charles
EA do use custom eminence drivers - the 10" that I had apart was a dual concentric with a decentish compression driver bolted on the back. I think it was a P-audio or possibly a B&C - I can't remember now. They may use the output of the compression to keep their efficiency figures up a bit. but 103 is probably not far off. Eminence give a good honest account of exactly how they rate their drivers on their website.
TLs work by absorbing most of the midband rear wave energy from the driver which can cause coloration if it's allowed to bounce around within the box. You have to get the length and tapering of the line exactly right so that midband frequencies are absorbed but low frequencies exit the port in phase with radiation from the main driver thus reinforcing low end response.
The loading effects on the driver in a TL are different from those in vented or sealed boxes. You don't get the "springiness" air compliance issues that you do in a sealed box where you do nothing with the rear wave. The air is free to move in and out of the line at low frequencies but the cone never fully unloads as it does in a vented box. This means the excursion is more controlled the roll-off is much shallower and distortion is lower. In a good TL the roll-off begins lower and is shallower than the same driver could achieve in a closed box.
TLs have a bad rap because they are really hard to design well and require lots of R&D to get right. There is a lot of misinformation and some bad designs from the past which just don't work. They are better understood now than they have been in the past and there are some math cad sheets available to help you design which appear to produce reliable results. Not many people go down the TL route because the cabinets are complex and often large/heavy. If you build a DIY one and it performs poorly that's a lot more effort wasted than with a vented or sealed box.
PMC appear appear to have cracked the TL design with spectacular results. Their BB5s are the best speakers I've ever heard and the DB1 has an amazing response for its size.
http://www.pmcloudspeaker.com/index2.html
Olly
TLs work by absorbing most of the midband rear wave energy from the driver which can cause coloration if it's allowed to bounce around within the box. You have to get the length and tapering of the line exactly right so that midband frequencies are absorbed but low frequencies exit the port in phase with radiation from the main driver thus reinforcing low end response.
The loading effects on the driver in a TL are different from those in vented or sealed boxes. You don't get the "springiness" air compliance issues that you do in a sealed box where you do nothing with the rear wave. The air is free to move in and out of the line at low frequencies but the cone never fully unloads as it does in a vented box. This means the excursion is more controlled the roll-off is much shallower and distortion is lower. In a good TL the roll-off begins lower and is shallower than the same driver could achieve in a closed box.
TLs have a bad rap because they are really hard to design well and require lots of R&D to get right. There is a lot of misinformation and some bad designs from the past which just don't work. They are better understood now than they have been in the past and there are some math cad sheets available to help you design which appear to produce reliable results. Not many people go down the TL route because the cabinets are complex and often large/heavy. If you build a DIY one and it performs poorly that's a lot more effort wasted than with a vented or sealed box.
PMC appear appear to have cracked the TL design with spectacular results. Their BB5s are the best speakers I've ever heard and the DB1 has an amazing response for its size.
http://www.pmcloudspeaker.com/index2.html
Olly
demanddeepbass said:
A TL has a much broader definition then that... what you are describing is a close to aperiodic TL, and in the case under consideration, probably not an accuarte description. The line is almost surly stuffed until it is completely aperidic, because there is no way you will fold a TL that uses quarter-wave action into that box.
You are right on some points. Martin's MathCad sheets can do a very good job of simming a TL -- and therefore makes the amount of R&D not much more than any other box, but here where it is likely stuffed to the 9s, we are getting out of the calibrated extent of the sheets -- that isn't going to stop us from trying.
With the advent of MJK the use of TLs -- particularily in diy -- has exploded.
dave
dave
demanddeepbass said:
PMC is pretty much the current evolutionary result of the Radford>IMF>TDL family. Primamrily Dalines with tapered lines, and minimal damping. I have heard that a copy of MJK has found its way into the facility.
dave
The cab that I linked to has a coaxial driver. EA don't seem to mention whether the frequency response is to -3dB or -6dB or what.
This isn't entirely impossible. I don't exactly remember what the lower mid range sounded like in the model I heard.
I think you're right, we all know that manufacturer's aren't entirely honest. Most musical instrument cabs usually seem to be about 98/99/100dB @ 1W @ 1m efficient. The 103dB figure is highly suspicious.
Yeah, I tend to agree, I prefer the really deep stuff.
Cone control would be very handy for me (to protect the drivers) since my bass still outputs a lot of sound/noise well below 20/30Hz from finger noise / slap 'n pop.
Yeah, was thinking of building a bass cab with 2x12" drivers a while ago but they all seemed to have a rather high Fs. Maybe this is because they are very popular paired up with horns (and optional woofers) in PA tops. I'd imagine the only time they'd be used to cover bass in the 40Hz range is in a bass guitar cab.
So...something with a low Vas you think? Am I right in thinking this would be a driver with a softer spider/surround and less springy? If so would you use low Vas driver because the cabinet is providing a lot of the springiness to make up for it?
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