@jccart yep! https://www.diyaudio.com/community/threads/10-cd-horn-2-way.375829/
@Juhazi that measurement doesn't look right, I don't know what woofer it is but it runs to 2% at 102db down to 50hz. Which driver is it, please?
@Juhazi that measurement doesn't look right, I don't know what woofer it is but it runs to 2% at 102db down to 50hz. Which driver is it, please?
dibirama.it measurements systematically show high distortion (only THD%), like ScanSpeak 12" 30W that I showed. I checked at least ten woofers there. And their scale is different from others, lowest hor. line is 1%. And notice, lowest spl is 90dB at 1m which is rather high especially for drivers with low sensitivity like your TB, 84dB at 2.83V. Most of the drivers tested there are PA, which explains high spl they use.
In my previous post I showed a 12" subwoofer https://www.dibirama.it/home-page/s...30w-4558t00-sub-woofer-10-4-ohm-350-wmax.html
Compare to
or SB Acoustics MW16TX-8
compare to HifiCompass of same MW16TX-8 in relative dB, played here with 2,8V (sensitivity 88dB)
In my previous post I showed a 12" subwoofer https://www.dibirama.it/home-page/s...30w-4558t00-sub-woofer-10-4-ohm-350-wmax.html
Compare to
AUDAX HM100Z0 (4" midrange)
compare to HifiCompass of same MW16TX-8 in relative dB, played here with 2,8V (sensitivity 88dB)
I found some for the w5-1138smf here as well:
https://techtalk.parts-express.com/.../1441425-driver-testing?p=1441732#post1441732
https://techtalk.parts-express.com/.../1441425-driver-testing?p=1441732#post1441732
Yep, it is much better than others below 100Hz, no question. Those are in absolute FR. In relative or % differene would be even more dramatic
My distortion measurements for W5-1138SM
Sealed alignment. 5L box. Wool felt damping inside. IMD amp with Hypex UCD modules + UMIK-1.
First three measurements taken at 80cm, last two taken at 20cm but with db level maintained from 80cm.
Sealed alignment. 5L box. Wool felt damping inside. IMD amp with Hypex UCD modules + UMIK-1.
First three measurements taken at 80cm, last two taken at 20cm but with db level maintained from 80cm.
That's pretty good for a single small woofer. No problems and you are planning to use 2 per speaker.
It certainly looks good in measurements.........just don't know what it'll sound like at 250hz.....it's pretty stiff and that surround
But there's no getting around it looks like a pure piston for 3 and a half octaves
The OP can tell us how it 'sounds'.......shelf it with some DSP and 1k and just listen with some music....vocals,etc......how does the midbass sound......?
If it works out, might as well go with 4 of em per speaker ......a WWCWW or WWWCW
But there's no getting around it looks like a pure piston for 3 and a half octaves
The OP can tell us how it 'sounds'.......shelf it with some DSP and 1k and just listen with some music....vocals,etc......how does the midbass sound......?
If it works out, might as well go with 4 of em per speaker ......a WWCWW or WWWCW
Yes, when compared to others it does look promising and I expect to shave 3-6db off those distortion measurements with two drivers.
Tomorrow I will try and do some listening tests while I work and might do some room measurements in their proposed positions.
Looks like I can still have my 160/180m stick but just turned 90 degrees. Unless I shoe-horn them in to a 160mm baffle but then it limits grille options to deter curious fingers.
Next I will need to pick a 4" or 5" mid. Or coax.
Tomorrow I will try and do some listening tests while I work and might do some room measurements in their proposed positions.
Looks like I can still have my 160/180m stick but just turned 90 degrees. Unless I shoe-horn them in to a 160mm baffle but then it limits grille options to deter curious fingers.
Next I will need to pick a 4" or 5" mid. Or coax.
Curiouser and curiouser...
I measured the test box in 6 positions and averaged all the Sofa Left and Sofa Right measurements together. The speaker was moved from under one speaker to the other for each side:
Speaker Right / Sofa Right
Speaker Right / Sofa Centre
Speaker Right / Sofa Left
Speaker Left / Sofa Right
Speaker Left / Sofa Centre
Speaker Left / Sofa Left
I measured the test box in 6 positions and averaged all the Sofa Left and Sofa Right measurements together. The speaker was moved from under one speaker to the other for each side:
Speaker Right / Sofa Right
Speaker Right / Sofa Centre
Speaker Right / Sofa Left
Speaker Left / Sofa Right
Speaker Left / Sofa Centre
Speaker Left / Sofa Left
OK, so, for clarity here are the individual measurements as I believe the averages make it look quite harsh.
There is definitely some room energy from 150-250hz in some positions.
Enough to get upset by? I don't know.
It does make centering the project around bass response seem less critical given the mixed responses.
And nearfield run through VituixCAD baffle sim merged with far field measurement:
There is definitely some room energy from 150-250hz in some positions.
Enough to get upset by? I don't know.
It does make centering the project around bass response seem less critical given the mixed responses.
And nearfield run through VituixCAD baffle sim merged with far field measurement:
You should not do listening distance measurements yet, they are corrupted with room modes and reflections. For design set mic at 1m distance at or below tweeter height. Aim speaker obliquely in the room, preferably on some kind of turntable. Measure at least at 15 and 30 deg off-axis too. And keep this setup standard for all later measurements.
Then for analysis set impulse gating right window so that first reflection impulse peak is avoided, typically 4-6ms. This is too short for bass, but it is actually the last stage. Mid and tweeter matching comes first, it is most important and difficult!
Your measuements so far look ok considering how they were taken, nothing strange there. Dip at 2kHz comes from 2 woofers interference, but speakers in the photo look pretty different...
Then for analysis set impulse gating right window so that first reflection impulse peak is avoided, typically 4-6ms. This is too short for bass, but it is actually the last stage. Mid and tweeter matching comes first, it is most important and difficult!
Your measuements so far look ok considering how they were taken, nothing strange there. Dip at 2kHz comes from 2 woofers interference, but speakers in the photo look pretty different...
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@Juhazi Sorry, I should have clarified the reason for taking the room measurements. As discussed in posts 25-28 we discussed the idea of positioning woofers at floor level to avoid the apparent floorbounce. This is evident in room measurements for my previous build and the current Genelecs (posts 1 and 20, respectively) centering around 200hz and believed to be due to woofer height.
Ergo, the test is to assess the real world application of a woofer at floor level, its effect on floor bounce and the viability of a 250hz crossover to mid from the W5-1138. From measurements, it appears floor bounce is not the culprit as the room adds energy from 175-260hz creating nulls.
Ergo, the test is to assess the real world application of a woofer at floor level, its effect on floor bounce and the viability of a 250hz crossover to mid from the W5-1138. From measurements, it appears floor bounce is not the culprit as the room adds energy from 175-260hz creating nulls.
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I'm really impressed with these little drivers and dare i say it but that's one heck of a midwoofer on paper..........
The dip centered at 2k.....i bet that's a surround hiccup. That cone with half the surround is only 100mm in diameter so 1/4 wavelength falls right into it
I wonder what the off axis response looks like in the upper mid with that profile........surround is almost a waveguide for god sake!
personally, i'd give them an ear test as they are with no crossover help and on the stands in that box.........what i'd be listening for is congested midbass. I'm fortunate to have a recording studio at home so i wouldn't hesitate to give em the true test with a clean Fender Precision and some play through.....no better signal test that i know of.
@mayhem13 They do measure well but the one you have highlighted is still 75db @ 80cm so is it still that good?
I'll try and do some long listening next week when I am working from home. Hard to know what listen for as at this point we kinda get in to WhatHifi Magazine superlatives when reporting back🙂
Anyway, the following graph is averaged room measurements from my previous system, my genelecs and the W5 sub test. This shows a common issue between 150-250hz despite the woofer height being different (570mm, 830mm and 200mm respectively) in each pair.
This draws in to question whether I should shoot for a 250hz crossover to mid or use the W5 as a more pure sub/woofer and cross around 100hz.
- The higher crossover means I need to find a midrange that is clean from 250-2000hz.
Front mounting the W5 would be essential
- The lower crossover means I need to find a midwoofer that is clean from 100-2000hz.
Side mounting the dual W5 and keeping a very slim baffle becomes an option.
I'll try and do some long listening next week when I am working from home. Hard to know what listen for as at this point we kinda get in to WhatHifi Magazine superlatives when reporting back🙂
Anyway, the following graph is averaged room measurements from my previous system, my genelecs and the W5 sub test. This shows a common issue between 150-250hz despite the woofer height being different (570mm, 830mm and 200mm respectively) in each pair.
This draws in to question whether I should shoot for a 250hz crossover to mid or use the W5 as a more pure sub/woofer and cross around 100hz.
- The higher crossover means I need to find a midrange that is clean from 250-2000hz.
Front mounting the W5 would be essential
- The lower crossover means I need to find a midwoofer that is clean from 100-2000hz.
Side mounting the dual W5 and keeping a very slim baffle becomes an option.
A little progress update:
Moving a little sideways I thought a good plan would be to make the system a bit modular as I am still undecided on co-ax or woofer/horn. So the current plan is to make two sealed subs which will also act for stands for the MF/HF.
Prototype cabinet - dimensions are 650 x 160 x 200mm and is about 11 litres net.
The baffle (front) has not been glued on yet as I am doing some burn-in and sweeps before I do this.
The drivers are deeply recessed to accommodate a flush fabric grille and to centralize the magnet weight within the cabinet for better balance.
Due to the internal length I expect a standing wave around 250hz so my plan is to stuff the entire top area to eliminate it. My intial plans were to use melamine foam/magic sponges, I attempted to use contact spray adhesive but it hasn’t provided the strength I need to keep the melamine foam consistently stuck together and to be manipulated in to the space.
Prices for full sheets of melamine foam make it a little prohibitive (unless someone in the UK can help?) so I may end up using rockwool again even though I am not too keen to.
Moving a little sideways I thought a good plan would be to make the system a bit modular as I am still undecided on co-ax or woofer/horn. So the current plan is to make two sealed subs which will also act for stands for the MF/HF.
Prototype cabinet - dimensions are 650 x 160 x 200mm and is about 11 litres net.
The baffle (front) has not been glued on yet as I am doing some burn-in and sweeps before I do this.
The drivers are deeply recessed to accommodate a flush fabric grille and to centralize the magnet weight within the cabinet for better balance.
Due to the internal length I expect a standing wave around 250hz so my plan is to stuff the entire top area to eliminate it. My intial plans were to use melamine foam/magic sponges, I attempted to use contact spray adhesive but it hasn’t provided the strength I need to keep the melamine foam consistently stuck together and to be manipulated in to the space.
Prices for full sheets of melamine foam make it a little prohibitive (unless someone in the UK can help?) so I may end up using rockwool again even though I am not too keen to.
Can I ask why you are leaving all of that efficiency to reproduce bass from a ported/PR box on the table, just to boost it back up with DSP and require a bunch more power to get there?
I understand the process if it only takes +3dB even though that is still twice the power applied over the vented option. Then there are others that shrink the box too and have to apply up to +15dB to make it right again. There is just such an awkward aversion to the 'horrendous hated vented box', that it's wasting the potential hammering bass of a properly tuned box.
As an example, at the SDC back in August, there was a short petite tower 2way with a Neo8 style planar and a Dayton Epique E150HE44 in a sealed box. Guy said he had +20dB added to the bottom end. This is likely due to a 3 fold loss of a sealed box, with a low sensitivity woofer in full BSC loss having to keep up with a higher sensitivity planar. He said at home they sound good on the 60Wx4 DSP amp he was using, but they clipped HARD at the event. I asked if he had considered venting the woofer to gain efficiency, and he looked at me like I was afflicted with some disease.
Just wondering if you can shed some light on this approach...
I understand the process if it only takes +3dB even though that is still twice the power applied over the vented option. Then there are others that shrink the box too and have to apply up to +15dB to make it right again. There is just such an awkward aversion to the 'horrendous hated vented box', that it's wasting the potential hammering bass of a properly tuned box.
As an example, at the SDC back in August, there was a short petite tower 2way with a Neo8 style planar and a Dayton Epique E150HE44 in a sealed box. Guy said he had +20dB added to the bottom end. This is likely due to a 3 fold loss of a sealed box, with a low sensitivity woofer in full BSC loss having to keep up with a higher sensitivity planar. He said at home they sound good on the 60Wx4 DSP amp he was using, but they clipped HARD at the event. I asked if he had considered venting the woofer to gain efficiency, and he looked at me like I was afflicted with some disease.
Just wondering if you can shed some light on this approach...