Desperately seeking taut bottom (end)

[dabbler]

A pair of Dyanudio active 2-ways, Acoustic Energy AE1's, collectible JBL's and a couple of full range drivers sit in my spare room collecting dust while a pair of $30, 1980's mid-fi celestion ditton 100's take prime position in my lounge room set-up.

You ask why? Broken ears? Probably. But if you ignore the ringing of the paper thin particle-board cabinet and the tipped up response with shouty midrange (first order crossover without BSC or tweeter lpad!) there is something these little fellas do that the others cannot; Articulate, detailed and natural sounding mid bass. Drums are so taut, well defined and clear even at low volumes. The sealed box starts to roll off from 90 odd hertz so there isnt much happening down low (I use a sub anyway) but what is there is just done so well. It reminds me of the open baffle bass sound yet more dynamic.

I have tried plugging the ports of the other speakers but alas I dont get the same effect. I guess the ditton paper midbass was designed to sing in a sealed cabinet.

So while I do like the sound of the dittons (after a bit of EQ) I would like to see if there is anything else out there can match their low-end and do better in the upper registers, with a little more SPL's. I am looking for builds, kits, and even commercial offerings that anyone can recommend. I just ask that your suggestions come from personal experience rather than specualtion unless there are certain driver specs or set of "numbers" that can predict this kind of low-end characteristic I am hopeless with passive crossovers and have sold my DCX2496 so I wont be able to dive into my own 2-way design with much confidence. Though I would be happy to try a simple (first order?) crossover with any 2 drivers that are partial to it and are easy to work with. As long as the bottom is taut, I am willing!

[DrDyna]

Originally Posted by dabbler

As long as the bottom is taut, I am willing!

Oh my!

Kidding aside, I've generally found that drivers with slightly lower cms values tend to sound a little quicker and snappier, but it might be in my head.

Perhaps someone has more insight.

[fatmarley]

Just wrote a large reply and lost it

Snell K
Yamaha NS1000
Linn Kan k2 (very fussy about partnering equipment and needs a subwoofer)

I've just built a design using the same 8" paper midbass driver as the Snell K and a large waveguide tweeter, but it's work in progress.

[jeffbook]

Dipole bass

Linkwitz Lab - Loudspeaker Design

[Jay]

Originally Posted by dabbler

I just ask that your suggestions come from personal experience rather than speculation unless there are certain driver specs or set of "numbers" that can predict this kind of low-end characteristic

There is no spec that can predict what low-end characteristics you are talking about

But I think it is not about number (hertz). The impression of deep and taut bass may come from a gentle slope of a sealed enclosure, but surely may come from a perfect blend of the drivers (in a good crossover).

So what you can do is:
(1) Build a TL speaker.
(2) Build a perfect speaker from good designers. This speaker is rare, you have to pay attention on its "reviews", or those that win some kind of speaker building competition. Lately I read that thread about Mark K's ER18DXT speaker. I don't have "personal" experience with the design, but my experience tell me that you will not be disappointed. (Well what if I were inexperienced but I had "personal" experience with a poor speaker that I thought had a remarkable bass?)

Originally Posted by dabbler

Though I would be happy to try a simple (first order?) crossover with any 2 drivers that are partial to it and are easy to work with. As long as the bottom is taut, I am willing!

The Mark K's speaker is 2nd order (acoustical). It is not easy to build a speaker with simple crossover like this. Many top quality commercial speakers use simple 1st order crossover because the driver is specially designed for that. Most commercial DIY drivers are not suitable for 1st order filter.

[dabbler]

Originally Posted by DrDyna

Oh my!

Kidding aside, I've generally found that drivers with slightly lower cms values tend to sound a little quicker and snappier, but it might be in my head.

Perhaps someone has more insight.

Thats interesting. I have heard the same about low Fs and Le. I dont know how true it is.

Snell K
Yamaha NS1000
Linn Kan k2 (very fussy about partnering equipment and needs a subwoofer)

NS1000 would be nice but space is limited, 6.5" max is my preference. I'll keep an eye on ebay for Linn Kan. Am interested to hear your long reply if you have the time!

Dipole bass

Been there, done that and while it worked well, it just took up too much space. Plus the multi-driver, multi-amp active thing is just too fussy for me. I am getting a similar sound (and in some respects better) from the dittons in the sealed box and they take up much less space. There is just enough room interaction to keep the low-end dynamic without getting bloated.

A few observations and ramblings:

Tapping the paper cone of the ditton midwoofer gives a dry sound unlike the dynaudio polycone or aquaplas cone of the JBL (which have a higher pitch when tapped). The ditton cone is fairly stiff but not very thin and has no shiny coating i.e the texture is soft to the touch like tightly stretched fabric.

There is a very slight coloration to the sound but certainly nothing close to the fostex full range drivers I own. It is not objectionable in any way.

A frequency response measurment shows nothing out the ordinary, just typical gentle roll-off from the sealed cabinet. It would be interesting to measure driver TS parameters but I dont have the equipment.

Im staring to feel that the 400hz and down range is very important. Quick transients here hold the frequencies above together and keep the sound cohesive.

The search continues

[dabbler]

Originally Posted by Jay

There is no spec that can predict what low-end characteristics you are talking about

But I think it is not about number (hertz). The impression of deep and taut bass may come from a gentle slope of a sealed enclosure, but surely may come from a perfect blend of the drivers (in a good crossover).

So what you can do is:
(1) Build a TL speaker.
(2) Build a perfect speaker from good designers. This speaker is rare, you have to pay attention on its "reviews", or those that win some kind of speaker building competition. Lately I read that thread about Mark K's ER18DXT speaker. I don't have "personal" experience with the design, but my experience tell me that you will not be disappointed. (Well what if I were inexperienced but I had "personal" experience with a poor speaker that I thought had a remarkable bass?)



The Mark K's speaker is 2nd order (acoustical). It is not easy to build a speaker with simple crossover like this. Many top quality commercial speakers use simple 1st order crossover because the driver is specially designed for that. Most commercial DIY drivers are not suitable for 1st order filter.

Thanks Jay,

do you have the link to Mark K's project?

[Jay]

The Seas ER18DXT ported two way

[fatmarley]

Originally Posted by dabbler

NS1000 would be nice but space is limited, 6.5" max is my preference. I'll keep an eye on ebay for Linn Kan. Am interested to hear your long reply if you have the time!

If you do look for some Kans make sure you get the Mk2 version. The mk2s have a flatter frequency response than the mk1. They are very revealing and can sound harsh or bright with the wrong electronics. I used mine with modified Naim gear.

[RogerLancaster]

AVI ADM9.1 active speakers have one of the most open revealing sounds Ive ever heard at any price. The treble and mids are to die for, the bass initially sounds a little thin until you realise its actually very taught and defined. By comparison my passive speakers now, whilst generally very good, sound comparatively coloured.

Just thought Id offer my experiences

Originally Posted by dabbler

A pair of Dyanudio active 2-ways, Acoustic Energy AE1's, collectible JBL's and a couple of full range drivers sit in my spare room collecting dust while a pair of $30, 1980's mid-fi celestion ditton 100's take prime position in my lounge room set-up.

You ask why? Broken ears? Probably. But if you ignore the ringing of the paper thin particle-board cabinet and the tipped up response with shouty midrange (first order crossover without BSC or tweeter lpad!) there is something these little fellas do that the others cannot; Articulate, detailed and natural sounding mid bass. Drums are so taut, well defined and clear even at low volumes. The sealed box starts to roll off from 90 odd hertz so there isnt much happening down low (I use a sub anyway) but what is there is just done so well. It reminds me of the open baffle bass sound yet more dynamic.

I have tried plugging the ports of the other speakers but alas I dont get the same effect. I guess the ditton paper midbass was designed to sing in a sealed cabinet.

So while I do like the sound of the dittons (after a bit of EQ) I would like to see if there is anything else out there can match their low-end and do better in the upper registers, with a little more SPL's. I am looking for builds, kits, and even commercial offerings that anyone can recommend. I just ask that your suggestions come from personal experience rather than specualtion unless there are certain driver specs or set of "numbers" that can predict this kind of low-end characteristic I am hopeless with passive crossovers and have sold my DCX2496 so I wont be able to dive into my own 2-way design with much confidence. Though I would be happy to try a simple (first order?) crossover with any 2 drivers that are partial to it and are easy to work with. As long as the bottom is taut, I am willing!