I'm gonna fix the driver permanently on the cabinet. Then, I'll do the listening test again with lesser quantities of polyfill.
I don't think it's a phase issue but I'll double check the connections when I get back from work.
1. I still haven't fixed the driver because one screw slipped while tightening and the MDF around that area split open
! I'm gonna glue the driver to the cabinet permanently2. I have changed the "grill" which was a 1mm sieve and replaced it with a welded mesh. Then I removed all of the polyfill and just added approx 20gm near the grill and around the driver. The sound is much more bassy now.
3. I have checked the wiring and it was correctly done.
4. Should I build a sub ?
Can I use the Eminence Alpha 15 ?
Change the position for different sound
The placement of the speakers in the room affect the sound greatly. Room size, walls, also Your listening position.
My experiment was with BSC circuit, speakers closer to wall, and I was listening on the sofa close the opposite wall (I know it is not perfect) at about 4meter distance. Then the bass was unbelievable from this small speaker.
If I change anything, the bass is less pronounced, but the speakers are very balanced. Sitting on the floor also give deeper bass.
Try experimenting.
The placement of the speakers in the room affect the sound greatly. Room size, walls, also Your listening position.
My experiment was with BSC circuit, speakers closer to wall, and I was listening on the sofa close the opposite wall (I know it is not perfect) at about 4meter distance. Then the bass was unbelievable from this small speaker.
If I change anything, the bass is less pronounced, but the speakers are very balanced. Sitting on the floor also give deeper bass.
Try experimenting.
1. I still haven't fixed the driver because one screw slipped while tightening and the MDF around that area split open
2. I have changed the "grill" which was a 1mm sieve and replaced it with a welded mesh. Then I removed all of the polyfill and just added approx 20gm near the grill and around the driver. The sound is much more bassy now.
3. I have checked the wiring and it was correctly done.
4. Should I build a sub ?
Can I use the Eminence Alpha 15 ?
Affirmative !
I have placed the speaker close to the wall now.
The problem with my listening room is that its not a "room" at all
Its a sort of a hall or lobby with the stair case on one side and the doors to bedrooms on the other sides. SO, the bass gets "sucked out" to the ground floor through the staircase.SO, to measure the effect of polyfill on the SPL, I did a test.
I generated test tones using my PC (Xonar DX soundcard) and fed it to the TABAQ left channel through my Yamaha AS500 amp. The SPL measurement was done with my iPhone placed at 50cm from the driver.
Here is the result but I don't know how to analyse it
I generated test tones using my PC (Xonar DX soundcard) and fed it to the TABAQ left channel through my Yamaha AS500 amp. The SPL measurement was done with my iPhone placed at 50cm from the driver.
Here is the result but I don't know how to analyse it
Attachments
Few questions to the construction of Tabaq
Hello everyone,
Should I have a few questions to the construction of Tabaq:
1. I studied the modified plan Tabaqat from Bjørn, and I tried to draw it here – option „A“. I hope it's right. On this plan is also the second option "B" with a different shape of port. The port is of course still the same length (9.7 cm), but it is headed down. This allows the driver to move higher (closer to ears). Is this second variant „B“ better than the first „A“?
2. Bjørn told me, that sharp edge on a corner cabinet is not good, but unfortunately I did not understand, if I may move side wall enclosure in front of the front wall (about 3-4 mm), if the corners are rounded as shown here.
3. How a lot use of wool? Do i understand correctly that into the whole area of the upper 2/3 of the cabinet will give a total 100 g of wool? If Bjørn did this already calculated, it makes sense to try a different quantity?
Thanks everyone for your help and advice
Bye Pavel
Hello everyone,
Should I have a few questions to the construction of Tabaq:
1. I studied the modified plan Tabaqat from Bjørn, and I tried to draw it here – option „A“. I hope it's right. On this plan is also the second option "B" with a different shape of port. The port is of course still the same length (9.7 cm), but it is headed down. This allows the driver to move higher (closer to ears). Is this second variant „B“ better than the first „A“?
2. Bjørn told me, that sharp edge on a corner cabinet is not good, but unfortunately I did not understand, if I may move side wall enclosure in front of the front wall (about 3-4 mm), if the corners are rounded as shown here.
3. How a lot use of wool? Do i understand correctly that into the whole area of the upper 2/3 of the cabinet will give a total 100 g of wool? If Bjørn did this already calculated, it makes sense to try a different quantity?
Thanks everyone for your help and advice
Bye Pavel
Attachments
1. Your solution is one option to raise the level of the driver slightly.... Another way would be to angle the cabinet backwards slightly whilst including a longer rear foot-print.
2. There is a thing called baffle step diffraction. This happens around the frequencies where the wavelength approaches that of the distance from the driver to the edge of the cabinet. Essentially, a sharp edge angle results in a more violent transition zone with greater magnitude. A large radius edge to the cabinet (as large as practical), eases the transition allowing it to be dealt with more easily by electronics or DSP.
3. Dacron or a blend of synthetic fibres with wool or cotton is the usual cabinet stuffing or wadding material. It's the cheapest reasonable option. Either "van insulation" or specialist audio products like MDM2 or Sonofil.
Another place to avoid sharp edges is the driver mounting area. As it's a full range driver, it should be recessed so the front plate is flush with the front face of the baffle.
HTH
J.
2. There is a thing called baffle step diffraction. This happens around the frequencies where the wavelength approaches that of the distance from the driver to the edge of the cabinet. Essentially, a sharp edge angle results in a more violent transition zone with greater magnitude. A large radius edge to the cabinet (as large as practical), eases the transition allowing it to be dealt with more easily by electronics or DSP.
3. Dacron or a blend of synthetic fibres with wool or cotton is the usual cabinet stuffing or wadding material. It's the cheapest reasonable option. Either "van insulation" or specialist audio products like MDM2 or Sonofil.
Another place to avoid sharp edges is the driver mounting area. As it's a full range driver, it should be recessed so the front plate is flush with the front face of the baffle.
HTH
J.
SO, to measure the effect of polyfill on the SPL, I did a test.
I generated test tones using my PC (Xonar DX soundcard) and fed it to the TABAQ left channel through my Yamaha AS500 amp. The SPL measurement was done with my iPhone placed at 50cm from the driver.
Here is the result but I don't know how to analyse it
Adding more polyfill muffles higher frequencies, right ?
So, should I just fill both speaker cabinets with 100gm of polyfill and call it a day ?
Edit:
By the way, I made a mistake in cutting the MDF panel and now the speaker is placed 220 mm from the inside of the top panel. Should I correct it to 203 mm ?
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It's not going to make very much of a difference. Though if you want to get it closer to the defined model, 15mm or 18mm plate could be installed inside the top cap..... Assuming it's not all glued around 4 sides. Otherwise "Mr saw" would be required to start the adjustment.
It's not going to make very much of a difference. Though if you want to get it closer to the defined model, 15mm or 18mm plate could be installed inside the top cap..... Assuming it's not all glued around 4 sides. Otherwise "Mr saw" would be required to start the adjustment.
Never been a big fan of Mr Saw. So, I will go the 17mm mdf gluing inside the top cap route 😄
sorry I still don´t understand
Hi Jerms,
Thanks for your answers, but unfortunately I still do not understand the item 2.
Can I make a side wall so as in the picture above? If so, it will be noticeable deterioration in sound or insignificant?
Thanks Pavel
Hi Jerms,
Thanks for your answers, but unfortunately I still do not understand the item 2.
Can I make a side wall so as in the picture above? If so, it will be noticeable deterioration in sound or insignificant?
Thanks Pavel