Hello,
I really like SB Acoustics Eka, but I'm planning to use them as bookshelf rather than having them on stands because I have small kids roaming around my flat.
What do you think about moving BR port to the front? Is it enough to increase height of the cabinet so that the port fits in the front panel and then adjusting the depth to preserve volume? Or will I mess up the cabinet tuning completely?
Michal
I really like SB Acoustics Eka, but I'm planning to use them as bookshelf rather than having them on stands because I have small kids roaming around my flat.
What do you think about moving BR port to the front? Is it enough to increase height of the cabinet so that the port fits in the front panel and then adjusting the depth to preserve volume? Or will I mess up the cabinet tuning completely?
Michal
You could measure the resonance. It may, for example, be possible to alter the length of the port.
On a bookshelf against a wall and on stands out in the room requires a different "baffle step correction" in the crossover. Is this addressed?
A ported 2 way, less so a 3 way, can have low level higher frequency sound from port resonances, cabinet resonances and radiation from the rear of the midwoofer. This is less audible, if at all, when the port is on the rear compared to the front.
If the internal volume is the same and the restrictions to air flow around the port entrances are the same then the tuning should be essentially same.
A ported 2 way, less so a 3 way, can have low level higher frequency sound from port resonances, cabinet resonances and radiation from the rear of the midwoofer. This is less audible, if at all, when the port is on the rear compared to the front.
If the internal volume is the same and the restrictions to air flow around the port entrances are the same then the tuning should be essentially same.
I'm sure you can move the port to the front if you keep the baffle width the same and preserve the volume:
SB Acoustics :: Eka Kit
SBAcoustics-61-NRXC
Similar SB driver there. Just the 4 ohm version. Reflex tuning is a bit vague IMO. Many different tunings available. When you add room gain, I don't think it makes a lot of difference.
My amp has a bass tone control, so I don't worry much.
SB Acoustics :: Eka Kit
SBAcoustics-61-NRXC
Similar SB driver there. Just the 4 ohm version. Reflex tuning is a bit vague IMO. Many different tunings available. When you add room gain, I don't think it makes a lot of difference.
My amp has a bass tone control, so I don't worry much.
Last edited:
The EKA has a BW3/BW3 crossover around 3kHz. Supports modest cost crossover parts, and safe high power tweeter operation.
Most diy designs using these same drivers favor a BW3/BW3 around 1800Hz - 2000Hz, in an effort to attenuate midbass cone breakup distortion.
Read discussion forums on crossover points to make an informed decision.
=======
A front port of adequate diameter to avoid air noise will perform well.
Most diy designs using these same drivers favor a BW3/BW3 around 1800Hz - 2000Hz, in an effort to attenuate midbass cone breakup distortion.
Read discussion forums on crossover points to make an informed decision.
=======
A front port of adequate diameter to avoid air noise will perform well.
I see nothing wrong with this kit design whatever. This is actually the new Mark II EKA design which adresses any cone breakup from the woofer with a 3.1kHz crossover. You will always trade off tweeter distortion versus cone breakup and take your beating on dispersion.
There is a breakup notch around 5kHz, which does the right things. Looks like an excellent speaker for a smallish room to me. 6" bass is usually criticised for light bass, so wall placement ought to be OK.
I hope you tell us how you get on, kalinowski. Nothing like actually doing it in the end! 🙂
There is a breakup notch around 5kHz, which does the right things. Looks like an excellent speaker for a smallish room to me. 6" bass is usually criticised for light bass, so wall placement ought to be OK.
I hope you tell us how you get on, kalinowski. Nothing like actually doing it in the end! 🙂
My quick on-axis sim of the SB Acoustics EKA revision2 design including baffle effects shows a midwoofer SPL bump from the paper cone breakup around 4-5kHz.
With a 6.5" diameter cone, the 15-30 degree off axis SPL around 4-5kHz may be smoother. Against the wall placement might be assumed common.
Attachments
I found this Audioexcite's kit using the same drivers as the EKA. The crossover is a bit different though. Any reasons to favor one to the other?
www.audioexcite.com >> Kensho Two – M3
Thanks,
Martin
www.audioexcite.com >> Kensho Two – M3
Thanks,
Martin
That's a 15cm main driver, not the 17cm as used in the Eka, so it would have to have a different crossover.
Today is a sunny day with many "bright and shiny" reflections......
Today.... I would spend your money on the SB_Acoustics aluminum cone SB17NAC35-4 and SB26ADC-4 with a 2,000Hz crossover which tracks Troels' design - can you cut edge bevels? like stepped-baffle tech?
SEARCH for cabinets+crossovers which use the SB17NAC35-4 + SB26ADC-4
Today.... I would spend your money on the SB_Acoustics aluminum cone SB17NAC35-4 and SB26ADC-4 with a 2,000Hz crossover which tracks Troels' design - can you cut edge bevels? like stepped-baffle tech?
SEARCH for cabinets+crossovers which use the SB17NAC35-4 + SB26ADC-4
Attachments
Thanks for the advice! I had my eyes on that Troels' design too.
I would rather do a flat baffle with roundover edges.
I would rather do a flat baffle with roundover edges.
17NRXC-4 ohm has Himalayas starting at 4.2k all the way to 10k. And 5-6dB dip around 1.3-1.4k (cone edge resonance) making the x-o a bit hard to do around 2k.
The newer version of the 17NRXC has bigger dust cap and according to Goran from
www.audioexcite.com
and newer version is more manageable. Really, I would go with NBAC series, as they seem flatter in 1-3k and cone break up is not so ugly, also people say it sounds more detailed with lower distortions.
I went with LR4 LP 1.9k, full BSC, similar to Troels; already tried T with RLC to reduce the 4.2k but it didn't worked for me as there was too much break up visible above 4k and too much attenuation in 2k. Right now I have around 20dB reduction of the pesky 4.2k peak. My baffle has 10deg slant with 20mm roundover, increasing to almost 30mm at the top, listening axis at tweeter, with tweeter some 15mm to the outside from center.
Michal, PM me, narazie
The newer version of the 17NRXC has bigger dust cap and according to Goran from
www.audioexcite.com
and newer version is more manageable. Really, I would go with NBAC series, as they seem flatter in 1-3k and cone break up is not so ugly, also people say it sounds more detailed with lower distortions.
I went with LR4 LP 1.9k, full BSC, similar to Troels; already tried T with RLC to reduce the 4.2k but it didn't worked for me as there was too much break up visible above 4k and too much attenuation in 2k. Right now I have around 20dB reduction of the pesky 4.2k peak. My baffle has 10deg slant with 20mm roundover, increasing to almost 30mm at the top, listening axis at tweeter, with tweeter some 15mm to the outside from center.
Michal, PM me, narazie
Last edited:
Wow, LineSource I tried to simulate the V2 x-o, midbass section and looks like the 4.2k break up is still there, big hole around 3.6k and bump around 1k. Horrible design IMO, will sound like a pair of headphones by Dre. Are you getting something similar to what I'm describing.
- Status
- Not open for further replies.