Hi Alex,
Do not use doubled sided tape it tends to be flexible and over time. and I am afraid that the contestant pull from gravity will eventually make the phase plug rub the voice coil.
It is an easy fix using 5 min. epoxy, use 4 toothpicks for spacers and let it set for an hour and they are ready to go.
Frank
Do not use doubled sided tape it tends to be flexible and over time. and I am afraid that the contestant pull from gravity will eventually make the phase plug rub the voice coil.
It is an easy fix using 5 min. epoxy, use 4 toothpicks for spacers and let it set for an hour and they are ready to go.
Frank
I have to agree completely with this post below. Ok, I”m not claiming to be an expert, I’m not, but I but I have learned how fiendishly complicated it can be, to consider all the issues of speaker design and it’s amazing how hard it is to work out a crossover by ear, and it’s true that the mini DSP gives you so many options it can get very confusing, so it really is almost essential to have a measurement system as he recommends.
Your comment brought back some memories, As a young adult many years ago (early 2001) I was on my way home my first trip to US for 3 months, and had bought almost a small suit case of vacuum tubes, from stores and eBAY... And I was warn that I might be checked for bringing out military gear because alot of the tubes were JAN grade... I was super nervous but later realize it was probably a joke.
Thank you for the feedbacks Variac and mbrennwa. I completely agree with both of you. I also ordered a UMIK-1 measurement microphone from MiniDSP as well to measure out the frequency response. It's almost next to impossible for my untrained ears to determine or pick out the differences if at all in freq ampl/phase alignments at different crossover frequencies.
Thanks again for all the inputs.
Regards,
Tom
Thanks again for all the inputs.
Regards,
Tom
I agree too. It doesn't take an expensive microphone to resolve the large
issues from crossovers that don't fit and driver peaks, and listening can take
care of most of the rest.
You don't have to measure, but you do have to listen. If you measure and
listen, it will usually get you to the best result with the least effort.
BTW, DIY B5 is coming to store soon.
Frank and all who responded,
Thanks for the guidance... Deed is done... Now the waiting for it to harden. Voice coil still moves freely... Was worried the epoxy overflow, only use a thin layer in the middle as well as fill up the gap in the speaker "pole”
Thanks for the guidance... Deed is done... Now the waiting for it to harden. Voice coil still moves freely... Was worried the epoxy overflow, only use a thin layer in the middle as well as fill up the gap in the speaker "pole”
Hi Alex,
I needed to do an experiment before I could answer the question regarding wizzer. Since the coating of the wizzer is very similar to epoxy, I tried to tear one cone and repaired it with epoxy, and it works very well.
I would recommend that you put just a little bit of epoxy, on the rear side of the wizzer and massage into the material. Remember to remove any leftovers. When the epoxy is dry it will not be visible. You don’t need to worry about the extra weight since the amount you need is close to nothing.
Hope this helps
Frank
I needed to do an experiment before I could answer the question regarding wizzer. Since the coating of the wizzer is very similar to epoxy, I tried to tear one cone and repaired it with epoxy, and it works very well.
I would recommend that you put just a little bit of epoxy, on the rear side of the wizzer and massage into the material. Remember to remove any leftovers. When the epoxy is dry it will not be visible. You don’t need to worry about the extra weight since the amount you need is close to nothing.
Hope this helps
Frank
hi Frank and all,
Finally, I got all the tools I need to do biamping/active Xover and make freq response my OB.
Equipment use
- FW F4 for the Sub Eminence beta 15'' and FW Alelph J for SAL drivers
- MiniDSP 2x4HD: EQ SAL drive and dual Eminence 15beta
- MiniDSP 2x4HD: Xover at 300 Mhz using SL filter with -12dB/slope
- UMIK-1 USB mic: fully calibrated at 0degree, placed the mic at ears level 90 degree perpendicular to the speaker at 1 meter distance
- Software: REW for EQ, measurement and HD-plugins for active Xover
- Speaker placement: 1 meter off the rear wall and off the corner of the room
- Sal Freq response before EQ: I see the big dip at 5.52 kHz. Does anyone know if this is expected for the driver ? or is it due to my room effect ? High frequency start to roll off around 700 Mhz
- Playing around with REW EQ. I can tame some of the bump at 2k, 3k and 58 Hz but not able to get rid of the dip. I wonder if adding a super tweeter like Fostex t90a can help with the dip at 5.52khz for the HF
The overall sounds of OB with this active Xover/biamping setup with miniDSP 2x4HD is improved compared to passive Xover but still not open and airy at the high frequency. I wonder if it's due to a big dip of freq at 5.52khz showed up in the SAL measurement. It's good at mid range and decent at the mid bass but the high frequency is still not right to my ears.
I'm only a newbie so I'm open to all suggestions from other experts. Should I use Supertweeter to cover up freq range from 5k - 20k ? Should I use different Xover frequency ? maybe Xover at 1khz ? since this is the same zone for HF of SAL. Any inputs are appreciated.
I wonder if the baffle size and the way I place SAL in the middle in separate piece of wood might contribute to the dip at 5khz and the frequency response that I see below
Below is the image of SAL before EQ and SAL after EQ in green
SAL Before EQ
SAL After EQ
Here's the overlay curves of all drivers. the PINK curve is the Xover of SAL and dual beta 15 at XO 300Hz using LR -12dB.
OB design and placement
Thanks,
Tom
Finally, I got all the tools I need to do biamping/active Xover and make freq response my OB.
Equipment use
- FW F4 for the Sub Eminence beta 15'' and FW Alelph J for SAL drivers
- MiniDSP 2x4HD: EQ SAL drive and dual Eminence 15beta
- MiniDSP 2x4HD: Xover at 300 Mhz using SL filter with -12dB/slope
- UMIK-1 USB mic: fully calibrated at 0degree, placed the mic at ears level 90 degree perpendicular to the speaker at 1 meter distance
- Software: REW for EQ, measurement and HD-plugins for active Xover
- Speaker placement: 1 meter off the rear wall and off the corner of the room
- Sal Freq response before EQ: I see the big dip at 5.52 kHz. Does anyone know if this is expected for the driver ? or is it due to my room effect ? High frequency start to roll off around 700 Mhz
- Playing around with REW EQ. I can tame some of the bump at 2k, 3k and 58 Hz but not able to get rid of the dip. I wonder if adding a super tweeter like Fostex t90a can help with the dip at 5.52khz for the HF
The overall sounds of OB with this active Xover/biamping setup with miniDSP 2x4HD is improved compared to passive Xover but still not open and airy at the high frequency. I wonder if it's due to a big dip of freq at 5.52khz showed up in the SAL measurement. It's good at mid range and decent at the mid bass but the high frequency is still not right to my ears.
I'm only a newbie so I'm open to all suggestions from other experts. Should I use Supertweeter to cover up freq range from 5k - 20k ? Should I use different Xover frequency ? maybe Xover at 1khz ? since this is the same zone for HF of SAL. Any inputs are appreciated.
I wonder if the baffle size and the way I place SAL in the middle in separate piece of wood might contribute to the dip at 5khz and the frequency response that I see below
Below is the image of SAL before EQ and SAL after EQ in green
SAL Before EQ
SAL After EQ
Here's the overlay curves of all drivers. the PINK curve is the Xover of SAL and dual beta 15 at XO 300Hz using LR -12dB.
OB design and placement
Thanks,
Tom
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Try moving your microphone to different positions (further away from the speaker, off axis) and see what the 5.5kHz dip does. If the dip goes away or moves to other frequencies, it's a geometry thing (baffle, room, reflections). If the dip stays, it's because the driver output has a dip.
I don't know if REW can take anechoic measurements, but that might be useful to understand a bit better what's going on. An impulse response showing the direct sound from the driver and the later reflections and the sound from the rear of the baffle might be useful to see.
I don't know if REW can take anechoic measurements, but that might be useful to understand a bit better what's going on. An impulse response showing the direct sound from the driver and the later reflections and the sound from the rear of the baffle might be useful to see.
He says yes, and it’s not “open and airy” so seems to be the case. A 5k dip could do this
I think. I believe the SAL response is quite flat so that notch might be for anonter reason than the driver.. There is a frequency response curve for the driver around somewhere.
I don’t think the super tweeter is the answer to fix a notch But I do have speakers with a full range mid and a tweeter above 5k that work well. Kind off a shame to cut off a lot of the SALs response. Probably just adding complexity at this point-better to fix the response (somehow!)
I think. I believe the SAL response is quite flat so that notch might be for anonter reason than the driver.. There is a frequency response curve for the driver around somewhere.
I don’t think the super tweeter is the answer to fix a notch But I do have speakers with a full range mid and a tweeter above 5k that work well. Kind off a shame to cut off a lot of the SALs response. Probably just adding complexity at this point-better to fix the response (somehow!)
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