In any case, you can’t go wrong with Beyma IMHO. Sometimes you’d wonder « why spend more ». They make great drivers.
The resistor/PTC combo will be measured and replaced by appropriate resistor value. I was actually impressed with any Beyma driver I have. I would really like to make the EVs to work without the distortion. Since it is so noticeable, I think there must be something wrong.
Another question: Only three weks ago you reported that these speakers »sounded great«. Yesterday you complained about distortions. What did you do to them in the meantime?
Best regards!
Best regards!
They sound great, dynamic, but I started noticing slight distortion when directly comparing with the Beymas, especially on the right hand side speaker. I first thought I was overdriving something, but when I turned down the volume, I could hear it still.
I did two things. I did not use them for 14 days and moved them around a bit. But nothing like dropping them or anything. I also had them this time oriented a bit differently. They were in a dry room at about 18 deg C. Maybe I just did not notice before?
I am going to investigate now🙂
I did two things. I did not use them for 14 days and moved them around a bit. But nothing like dropping them or anything. I also had them this time oriented a bit differently. They were in a dry room at about 18 deg C. Maybe I just did not notice before?
I am going to investigate now🙂
When I wrote right, I actually meant left...
I feel a bit stupid - I heard some problem on the left side and measured the right speaker...and it was a bit strange to me that I could hear the small difference in distortion shown in the measurements. So I turned on some music and there was clearly a problem in the left side, the right seemed OK. I could hear it even from the amp hiss that there is a difference. Then I measured the left speaker a while ago...and the results are below.
I still do not know what the cause is, I will take it apart when the kids go to bed, but I would guess a broken diaphragm. These were most probably the original ones and therefore very old and one just gave up.
I feel a bit stupid - I heard some problem on the left side and measured the right speaker...and it was a bit strange to me that I could hear the small difference in distortion shown in the measurements. So I turned on some music and there was clearly a problem in the left side, the right seemed OK. I could hear it even from the amp hiss that there is a difference. Then I measured the left speaker a while ago...and the results are below.
I still do not know what the cause is, I will take it apart when the kids go to bed, but I would guess a broken diaphragm. These were most probably the original ones and therefore very old and one just gave up.
Attachments
Could be one of the drivers on the left speaker has been replaced and the wires connected opposite polarity causing the 'hole' around 2kHz. (probably around the xo point ?)
Rob.
Rob.
So the HF driver was reversed compared to the right box - but it was connected correctly per the service manual info. So the HF driver wired IN phase shows no dip compared to the text book out of phase connection. The IRs now look similar on both sides. The PTC and resistor were taken off in both boxes and were replaced by a glass fuse.
I took the suspected driver apart and tried to clean the air gap a bit and then return the diaphragm back. When I did that, I noticed that the plastic front of the driver is slightly cracked - I will try to glue that tomorrow - dould that be the cause?
There is a hole in the back of the driver, in the right speaker, there was a sticker over it so I put it on the left driver as well. This most probably had zero influence, the hole is not through if I can tell. The left diaphragm looked OK with a small dent in the center. Maybe another cause? It did not look like a hole though. The reassembly seemed to improve the distortion a bit, but it is still worse than the other one.
Still the HF is falling on the left driver and there is another dip at 3 kHz (maybe due to room placement). I am not sure if cheap replacement diaphragms would improve the situation
Once I fix that crack and maybe get the replacement diaphragms and if it does not improve the situation, what would be a recommended modern screw on driver replacement?
I took the suspected driver apart and tried to clean the air gap a bit and then return the diaphragm back. When I did that, I noticed that the plastic front of the driver is slightly cracked - I will try to glue that tomorrow - dould that be the cause?
There is a hole in the back of the driver, in the right speaker, there was a sticker over it so I put it on the left driver as well. This most probably had zero influence, the hole is not through if I can tell. The left diaphragm looked OK with a small dent in the center. Maybe another cause? It did not look like a hole though. The reassembly seemed to improve the distortion a bit, but it is still worse than the other one.
Still the HF is falling on the left driver and there is another dip at 3 kHz (maybe due to room placement). I am not sure if cheap replacement diaphragms would improve the situation
Once I fix that crack and maybe get the replacement diaphragms and if it does not improve the situation, what would be a recommended modern screw on driver replacement?
Attachments
I hear good things about the FaitalPro HF146. Price is also not so bad. When you put 2 in the basket, it will show about 155 euros per one, some kind of discount.
Moteur de compression FaitalPRO HF146, 16 ohm, 1.4 pouce
Originally that was my choice for my build, but then out of nowhere I bought JBL 2451Js...I could not pass on the possibility of Unobtanium Beryllium sound 🙂
Moteur de compression FaitalPRO HF146, 16 ohm, 1.4 pouce
Originally that was my choice for my build, but then out of nowhere I bought JBL 2451Js...I could not pass on the possibility of Unobtanium Beryllium sound 🙂
EV SH-1502ER - poor man's Altec A7?
Poor man's Altec 1235 maybe: Altec - 1235 Voice of the Theatre | Gearogs Database & Marketplace
Surprised you like them up close, what with a 1600 Hz XO mated to a 15". It's a 'stretch' even coincident [604, 605 Altec].
GM
Poor man's Altec 1235 maybe: Altec - 1235 Voice of the Theatre | Gearogs Database & Marketplace
Surprised you like them up close, what with a 1600 Hz XO mated to a 15". It's a 'stretch' even coincident [604, 605 Altec].
GM
That's weird! The rest of the wiring the same?
The hole is mostly likely for manufacturing and/or assembly purposes.
Dents in compression driver diaphragms can affect the dome's pistonic response up high and if it has a loading cap the dent can 'tap'/'bounce' off it as the gap is 'feeler gauge' thin.
Neither speaker appears to be performing up to par, so measure the woofers, double check/clean everything and hope new diaphragms brings it all together. Do the horns seal well? No stress cracks?
Other than piezo horn screw ons, have zero performance knowledge of what's available other than what's published.
GM
Thanks for the input, GM. I did not know there was something like Altec 1235, that one would fit the description better, you are right.
All looks identical, today I will try to swap the backplates. I replaced both drivers with D.A.S. M-50s - they will need some equalization on the high end to match the performance of the EV DH3 in the high end (above 10 kHz). The funny thing is that the left box still sounds a bit more "dull" even with different drivers - although much more balanced and without distortion. I measured the caps and they seem to be within tolerance. I think it also will not hurt to replace all the wires inside. The capacitors are foil type both and it looks that maybe one of them was already replaced (the 2 uF for a square boxed 2u2). Would it make any sense to replace the caps as well?
There are some cracks on the back side of the right horn - but these should not matter as there is also a hole that served for filling the plastic with foam. But as I wrote, there is a crack in the plastic part of the driver - and it looks like there could be some air leak, I will try to glue and seal it. The FR can be compared only to other speakers measured in the same position - I am almost sure that some parts are room/placement related.
I like the sound of boxes with large HF horns. I actually liked the sound better when these were placed on the floor than with the horns at ear height (or, to be more precise, slightly above).
All looks identical, today I will try to swap the backplates. I replaced both drivers with D.A.S. M-50s - they will need some equalization on the high end to match the performance of the EV DH3 in the high end (above 10 kHz). The funny thing is that the left box still sounds a bit more "dull" even with different drivers - although much more balanced and without distortion. I measured the caps and they seem to be within tolerance. I think it also will not hurt to replace all the wires inside. The capacitors are foil type both and it looks that maybe one of them was already replaced (the 2 uF for a square boxed 2u2). Would it make any sense to replace the caps as well?
There are some cracks on the back side of the right horn - but these should not matter as there is also a hole that served for filling the plastic with foam. But as I wrote, there is a crack in the plastic part of the driver - and it looks like there could be some air leak, I will try to glue and seal it. The FR can be compared only to other speakers measured in the same position - I am almost sure that some parts are room/placement related.
I like the sound of boxes with large HF horns. I actually liked the sound better when these were placed on the floor than with the horns at ear height (or, to be more precise, slightly above).
Me too, since I have a pair mounted on Mantaray horns 😀 They sound very good. Woofers are the Altec 3156, crossover is an Ashly XR-1001, and a pair of Altec 9442A amps. I bought the Faital's as open box units at PE for $125 each.