I am looking into upgrading my low end and would like to have opinions if it is worth the effort to replace my present sub-woofer driver Scanspeak 26W/4558T00 to a 26W/8861T00 that I have relative cheap at hand. The driver is mounted in a 63 liter closed box made of 21mm MDF – see picture.
A more general part of my question is this: Will a dedicated woofer driver make less distortion than a sub woofer driver in the same box?
I have an active system with Uli Bruggeman linear phase filters.
Until recently I had a 3 way system with a “satellite” containing a Mundorf AMT tweeter and a 4” 12MU driver. During a listening session at a friend having high end Linn speakers I noticed that he had a better perspective in the upper bass region. Therefore I build a new “satellite” with an additional 5” 15MU bass/mid range driver. It works quite well. My XO is 200/900/3000.
I guess that a 6.5” driver would have blended better in, but i felt that the 5” gave some design freedom and a smaller cabinet.
I am looking forward to hearing you comments.
Br Erik
A more general part of my question is this: Will a dedicated woofer driver make less distortion than a sub woofer driver in the same box?
I have an active system with Uli Bruggeman linear phase filters.
Until recently I had a 3 way system with a “satellite” containing a Mundorf AMT tweeter and a 4” 12MU driver. During a listening session at a friend having high end Linn speakers I noticed that he had a better perspective in the upper bass region. Therefore I build a new “satellite” with an additional 5” 15MU bass/mid range driver. It works quite well. My XO is 200/900/3000.
I guess that a 6.5” driver would have blended better in, but i felt that the 5” gave some design freedom and a smaller cabinet.
I am looking forward to hearing you comments.
Br Erik
Attachments
Is your cabinet wide enough to fit the 6.5" 18WU/8741T00 ?
Experts like Troels Gravensen and Taipuu Audio use a sealed Scanspeak 4" 12MU, with a sealed 6.5" 18WU, plus a deep bass woofer(s). In a 0.4 - 0.5cuft sealed volume the 4-ohm 18WU/4741T00 sims -F3 = 71Hz and the 8-ohm 18WU/8741T00 in a 0.5-0.6cuft sealed volume sims -F3= 65Hz. The 6.5" 18WU will match the "tone" of the 12MU and also allow a low enough crossover to move the woofer "tone & phase & most room effect equalization" below critical vocals == below the important soundstage generation.
Taipuu Speakers DSP active speakers - Taipuu Speakers
Voice Coil magazine Feb 2009 issue has a review of the 18WU/4741T00 and 15WU4741T00 (yes WU)
Experts like Troels Gravensen and Taipuu Audio use a sealed Scanspeak 4" 12MU, with a sealed 6.5" 18WU, plus a deep bass woofer(s). In a 0.4 - 0.5cuft sealed volume the 4-ohm 18WU/4741T00 sims -F3 = 71Hz and the 8-ohm 18WU/8741T00 in a 0.5-0.6cuft sealed volume sims -F3= 65Hz. The 6.5" 18WU will match the "tone" of the 12MU and also allow a low enough crossover to move the woofer "tone & phase & most room effect equalization" below critical vocals == below the important soundstage generation.
Taipuu Speakers DSP active speakers - Taipuu Speakers
Voice Coil magazine Feb 2009 issue has a review of the 18WU/4741T00 and 15WU4741T00 (yes WU)
18WU/12MU is great combo, I currently listen to 18WU/12MU/R3004 3-way.
When used as top section of 4-way, I would not expect much differences between 18WU and 15WU, though 18WU makes more sense and can provide more lower midrange weight.
When used as top section of 4-way, I would not expect much differences between 18WU and 15WU, though 18WU makes more sense and can provide more lower midrange weight.
Thanks for sharing your thoughts.
I have decided to replace my woofer to the revelator. With that one i might be able to XO at 200 to 300 making the 15wu movement absolutely minimal. I am trying to lift off any stress in the midrange.
I will revert with the result.
Br Erik
I have decided to replace my woofer to the revelator. With that one i might be able to XO at 200 to 300 making the 15wu movement absolutely minimal. I am trying to lift off any stress in the midrange.
I will revert with the result.
Br Erik
I use a sub for the "Zeroth" octave; 16 to 32 Hz only. I have a new 11 inch woofer for above that to about 170 Hz (basically, 2 bass octaves 40 to 160 Hz). Then I have a smaller (6 inch) woofer from that up to about 700 Hz. Then I go to a wide band 4 in FR up to 4400 Hz. Super tweeter above that. I am getting very good results in this configuration. Each driver is only working in the band it is intended for. I have more ideas for improvements in the future. This is a 4 way with sub so 5 drivers per side total. Each driver has it's own amplifier (except the 2 woofers; another amplifier in the near future). Some people may think this is overkill or a bad idea. If they heard the results; they would change that idea immediately; this is all working very well together. Great control and dynamics; extremely musical and non-fatiguing; articulate; precise; accurate, etc...
Hi oldspkrguy
you write "Each driver is only working in the band it is intended for." in case of the 28W/8861T00 - how do I find the band they are intended to work within?
I have the impression that the intended band would relate to the driver's distortion at various frequencies. Is that wrong?
I will, of course, make trial and error with different XO to find the audible optimum!
Another thing:
I have seen that intermodulation distortion occurs when a driver has large movement for low frequency while also playing higher frequencies.
Hobby is generally overkill - we could live without but thats no fun.
Br Erik
you write "Each driver is only working in the band it is intended for." in case of the 28W/8861T00 - how do I find the band they are intended to work within?
I have the impression that the intended band would relate to the driver's distortion at various frequencies. Is that wrong?
I will, of course, make trial and error with different XO to find the audible optimum!
Another thing:
I have seen that intermodulation distortion occurs when a driver has large movement for low frequency while also playing higher frequencies.
Hobby is generally overkill - we could live without but thats no fun.
Br Erik
I have now replaced the sub driver with the Woofer 26W/8861T00. I Can state that I am pleased with the result. the Bas performance os very good, affecting the overall sound. I have selected 260 Hz XO and have not experimented with alternatives.
The frequency response in the 63 Liter cabinet is very good and in accordance with the specifications.
I use Acourate for making the phase linear filters and Acourate convolver. I am very pleased with the software.
Br Erik
The frequency response in the 63 Liter cabinet is very good and in accordance with the specifications.
I use Acourate for making the phase linear filters and Acourate convolver. I am very pleased with the software.
Br Erik
Attachments
Well, generally speaking I meant in the most linear portion of a driver's band; way before any break-up modes or even peaks and dips; where the FR curve is nice and smooth and FLAT. That is what I meant. Some people are totally against so many drivers and so many crossover points. I have Full Range all by themselves; 2-ways, 3-ways, now a 4-way with sub. The 4-way with sub sounds the best over all of my previous designs and I have a few more improvements coming up. I like 1st order X/O's the best but that means very careful driver matching. Right now; most of my LP X/O's are 1st order and my HP X/O's are 2nd order. This is to increase power handling only and not for tonal balance or "voicing".
I experiment all of the time; I usually always have my X/O boards on the back panel to allow for tweaking and future upgrades.
It would be nice to go all active with electronic crossovers but that will have to wait. After my final tweaks and improvements; I will get one more amplifier. Then; I will a separate amplifier for each driver pair with individual gain control; the next best thing to all active I think.