Replacement for Troels Audio Technology Classic 3 way

Hi,

A few years ago with help, I built Torels Gravesen Audio Technology Classic 3 way.

I really like the speakers, particularly the midrange but I long for a more body / bass. I've tried to add subwoofers but I couldn't get them to integrate successfully. It does seem a waste to sell the drive units for pennies, ideally Torels would have a design that uses the same drive units but with an additional bass unit, but I think his larger AT designs use different drive units and are a lot more complicated build, that I don't have the skill to build.

I'd like the look of his fussion or the loudspeaker designs, with 15 inch drive units but I'm not sure if the horns would be too aggressive for me. I've heard 25k plus JBL speakers and thought they sounded great but the high end was very slightly toppy for my liking, so I'm worried Troels design could have a similar issue. I've grown up listening to my dad's Leak 2075 and loved the natural effortlessly bass that is so different from modern small drivers, as if they are trying to over compensate.

Does anyone have any suggestions for me please. Or know of any designs where I could just add another bass unit in a new cabinet.

Thanks for your help.
 
I really like the speakers, particularly the midrange but I long for a more body / bass. I've tried to add subwoofers but I couldn't get them to integrate successfully.
What went wrong with the subs and what subs were they? Did you investigate your room acoustics? Did you try various positions of speakers and (when in use) the subs? Instead of buying new speakers (always fun) you could hire an expert that uses not only his/her ears but a microphone too, to optimize your current setup.
Does anyone have any suggestions for me please. Or know of any designs where I could just add another bass unit in a new cabinet.
There are loads of plans for bigger speakers. Adding a big woofer is the same as adding a sub. The moment you add a source low down, you have to design a crossover between sub and satellite. My 2 ct are you didn’t get to an optimal sub solution yet.
 
I understand the point about sub positioning, I didn't find they were booming, but I was struggling to set the crossover frequency correctly, too high and they were over lapping with the speaker, lower the output disappeared but any more gain would have been disproportionate.
I was using the sub woofers on industrial springs to isolate them from floor, to avoid room interaction. I'm now using them under some equipment, so might try again.

The sub woofers are, the forward facing version of these...
http://www.bkelec.com/HiFi/Sub_Woofers/XLS200.htm

Picture of setup attached. I don't really have room to place the elsewhere
 

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Your subwoofer is sealed and critically damped (Q0.5).
Main speakers are ported with substantial bass output (tuned ~ 35 Hz).
This is not a good combination to begin with, especially when the room is "difficult"; smaller standmount main speakers with lower bass output would combine better.
Like suggested before: stuff the ports of the 3 ways to cut lower bass and remove any bass peak.
Then your low Q subwoofers should not be difficult to integrate.
 
I understand the point about sub positioning, I didn't find they were booming, but I was struggling to set the crossover frequency correctly, too high and they were over lapping with the speaker, lower the output disappeared but any more gain would have been disproportionate.

???. If you are not using matched high/low pass filters for the sub/woofer the same as you are for your woofer/mid and mid/tweeter then a reasonable subwoofer integration stands almost no chance and good integration zero chance. It is effectively a requirement if sound quality is of interest. If you want high sound quality at low frequencies then controlling the room response becomes a requirement as well which is also a task for subwoofers.
 
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Yeah, task for microphone and some software and some work to make it all work nicely together as a system, the room and all the low frequency sources.

It's literally the room that dominates the lows, changing speakers (to another monopole) and putting them at the same location would yield about the same bass "quality". About nothing would change because it's not the speakers but the room, and how the sources and observer relate to it.

...
I didn't find they were booming, but I was struggling to set the crossover frequency..
Thats exactly how the problem with room modes shows up: can't turn sub volume up as it goes overwhelming, tune it down and now it doesn't hear at all and so on, there is no good balance exactly as you describe.

Room mode nulls make it sound you don't hear it, and peaks prevent you boosting it. Getting modal peaks and dips smoothed out allows you to hear bass withoit being boomy :) There could be 30-40db difference between highest peak and lowest dip, that is huge. If you can get that within 10db or even smaller it'll work much much better. Add a sub or two and a DSP, and take your time to make it work. Better option soundwise would be to go outside, get rid of the room, but thats not very practical. You just have to manage with the room you have.

Have fun! :)
 
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Does anyone have any suggestions for me please. Or know of any designs where I could just add another bass unit in a new cabinet.

Does reducing sligthy the capacitance value of C3021 (the damped bass parralel cap) on the shematic filter would help to tune the bass towards bass with more body and bigger feeling ? WHat's the cut-off of bass to mid? I will check the value of each C3021 with a capacitance meter and try too reduce by 1 uF increment for the beginning to listen to if any change you may like in your room. you can also play with the distance with the front wwal and side walls, you have maybe a null that is arming somewhere between 100 hz to 200 hz ?
 
It's literally the room that dominates the lows, changing speakers (to another monopole) and putting them at the same location would yield about the same bass "quality". About nothing would change because it's not the speakers but the room, and how the sources and observer relate to it.
I find it quite hard to believe people are not aware of this. It’s easy to perceive and hey, I wrote simple software on modal patterns in rectangular rooms more than thirty years ago. So this should be basic knowledge to anyone involved with music reproduction.
 
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Exactly, yet we see people tweak box calculators and worry about Qtc and few liters here and there to get 1db more output at some LF, but after putting the speaker into a room the response is bonkers regardless. Could be 10db peak and the whole process was in vain, EQ dip of 11db needed, instead of 10, for example. So, it's good to remind about in on every thread :D

While it's good to have speakers with fine anechoic capability, for example have enough extension and sensitivity, it just doesn't correlate whether the bass is perceived good or bad, it's almost irrelevant for the perception. Less steep way to express the same thing is that any speaker does not come with guarantee of good bass, only a person and process that adjusts the system to work witg the room could do that.

Example, I have certain 15" woofers, and box calculator suggests 150 litre reflex box, built that and midrange was poo as the box was lousy, lots of problems passband, it's bass section for 3way home speakers. Next box was 80 litre, still ported, still had to cut lows due to modes to get bass same level as rest of the system, and the box was still noisy affecting midrange performance of the system. Latest one is mere 50litre, no ports, Fs above 80Hz and finally no need to cut 30Hz, midrange is also fine now. Is it best, likely not, just an example how much room affects things.
 
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And many dacs have crappy mellow bass too due to bad layout synergies in the output stages as well as power supply stage... It's often a whole, however : in home filter tweaking, room placement, chair placement to try to find a better pressure node, can improve things to a not rdiculous margin. I would try the tricks given here before going to a sub and btw surely distributed subs would help more if it is the room !
 
I've recently added a power supply to my naim dac and that had opened up the sound. The bass seeming to have more weight / authority than before.

I experimented this afternoon with listening to the speakers with rolled up egg crate sponge in the ports (no subwoofer) it did reduce the ultimate slam and weight, but in other ways the speaker did sound a bit more controlled and less bright....

The midrange is in its own compartment, but when I made the speakers I lined the inside of the cabinet with 5mm hard plastic sound block material, rather than the fabric material... It helped make the speaker sound "quieter" at the time, as if less sound was coming through the cabinet, but I do wounder if I've made the inside of the speaker too reflective....

I used this
https://advancedacoustics-uk.com/products/soundproofing-mat-1200mm-by-2m-by-5mm-thick-10kg-membrane

It was inspired by an acoustic energy speaker that used a similar 3mm layer sandwiched between two layers of MDF.
 
The midrange is in its own compartment, but when I made the speakers I lined the inside of the cabinet with 5mm hard plastic sound block material, rather than the fabric material... It helped make the speaker sound "quieter" at the time, as if less sound was coming through the cabinet, but I do wounder if I've made the inside of the speaker too reflective....

I used this
https://advancedacoustics-uk.com/products/soundproofing-mat-1200mm-by-2m-by-5mm-thick-10kg-membrane

It was inspired by an acoustic energy speaker that used a similar 3mm layer sandwiched between two layers of MDF.
I’m sorry, but I think you were mislead there. There’s a big difference between sound proofing aka sound transmission reducing one one hand and sound absorbing on the other. Didn’t you use any foam or mineral or -newish- cotton wool as lining to dampen the rearward emitted sound in your cabinet at all? :eek:
 
No I didn't, I only added the loose white sheet of filler type material ( I can't remember the product name),
The midrange enclosure should be filled with sound absorbing material. A lot of materials will work, such as mineral wool, fiberglass insulation, polyester stuffing (pillow stuffing), sound absorbing foam. Some materials work really well, such as long fiber natural wool, shredded denim insulation, melamine foam.
 
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Thanks for the advice everyone.
I've just ordered 15mm wool felt, I plan to glue this to the face is for the plastic material already used.

Do I need to worry about reducing the internal volume of the speaker cabinet? It's gone for the 8mm felt designed to 20mm additional material overall.