Hi,
I finished the Jeff Bagby Adelphos kit, and it has boomy bass, in high
volume it's 'farting', here is a video:
Adelphos noise - YouTube
The cabinet is ported, I tried sealed but the bass sounds very elevated...more than the ported.
I 'upgraded' the crossover parts to Jantzen Alu Caps, Mills resistors and Jantzen Foil Inductors, all with same values.
The crossover is almost locked inside the cabinet, no easy access.
Any thoughts what went wrong and what can be done to fix it?
I tried to listen to other speakers in my room / electronics and no bass issues. Only with the Adelphos.
I tried the Adelphos with 2 different amps and got the same problem.
Thanks,
Itamar.
I finished the Jeff Bagby Adelphos kit, and it has boomy bass, in high
volume it's 'farting', here is a video:
Adelphos noise - YouTube
The cabinet is ported, I tried sealed but the bass sounds very elevated...more than the ported.
I 'upgraded' the crossover parts to Jantzen Alu Caps, Mills resistors and Jantzen Foil Inductors, all with same values.
The crossover is almost locked inside the cabinet, no easy access.
Any thoughts what went wrong and what can be done to fix it?
I tried to listen to other speakers in my room / electronics and no bass issues. Only with the Adelphos.
I tried the Adelphos with 2 different amps and got the same problem.
Thanks,
Itamar.
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How loud are you playing in dB? Saw the video and it sounds like the driver being pushed to its limits but I have had many Satori drivers and none does this except for the MW13 in a 2 way being pushed louder than it can handle.
85-90 dB, the driver is definitely pushed to its limits, but why? and how it can be fixed?
Usually I don't listen that loud, but you can hear the bass boost in low volume.
My Focal Kanta No1 plays very loud without any issues.
Usually I don't listen that loud, but you can hear the bass boost in low volume.
My Focal Kanta No1 plays very loud without any issues.
Is the port long enough?
Is there any damping in the box?
Did you verify the components were close to value?
I'm betting it's either a component of wrong value, or a miswire.
Wolf
Is there any damping in the box?
Did you verify the components were close to value?
I'm betting it's either a component of wrong value, or a miswire.
Wolf
I did a similar design and build in 2019 and bass was fine.
Check your box for any leaks as can have a detrimental effect on vented designs. The SB drivers have good gaskets so have a look around at the terminals and box joins. Make sure there is a clear path from the woofer to the inlet of the port as the damping may have moved. For designs like that I hang the damping sheet with a hole for the port and place it near the back wall as it helps to keep it in position.
Other than that you need to check all the xo components and the wiring, especially the polarity to the drivers. As a quick check you can reverse the speaker wires to the input terminal and have a listen. It should have less bass and sound phasey but if the bass is stronger, then you have a error.
Check your box for any leaks as can have a detrimental effect on vented designs. The SB drivers have good gaskets so have a look around at the terminals and box joins. Make sure there is a clear path from the woofer to the inlet of the port as the damping may have moved. For designs like that I hang the damping sheet with a hole for the port and place it near the back wall as it helps to keep it in position.
Other than that you need to check all the xo components and the wiring, especially the polarity to the drivers. As a quick check you can reverse the speaker wires to the input terminal and have a listen. It should have less bass and sound phasey but if the bass is stronger, then you have a error.
Also check if you have the 8 Ohm version of the MW16P. With a DMM you should get around 6R2 DCR across the terminals.
Had a look at the vid again. Either you have some hefty low boost switched on or your amp is at fault. Just my 2ct.
I checked it with 3 amps in my room:
Denon AVR-X 2400
YAMAHA A-S700
Cambridge Audio Edge W
and went to a dealer and checked it with the Unison Research Unico 250.
In all cases bass was boomy. My Focal Kanta No1 plays in louder volume with cleaner bass. I did something wrong for sure.
I checked the crossover dozen of times before sealing it in the cabinet, it's exact as the schematic suggests.
I will check again for leaks and maybe will try it with original crossover, although it's gonna be PITA.
Thanks for all your comments and suggestions!
Denon AVR-X 2400
YAMAHA A-S700
Cambridge Audio Edge W
and went to a dealer and checked it with the Unison Research Unico 250.
In all cases bass was boomy. My Focal Kanta No1 plays in louder volume with cleaner bass. I did something wrong for sure.
I checked the crossover dozen of times before sealing it in the cabinet, it's exact as the schematic suggests.
I will check again for leaks and maybe will try it with original crossover, although it's gonna be PITA.
Thanks for all your comments and suggestions!
Mike Chua was distinctly unimpressed with the 4 ohm Satori midbass:
He made the best of a bad job with the Thrush-CAT in 13L. Surprise that a smaller box worked better.
Thrush-CAT (Satori MW16P-4 with Morel CAT378) – AmpsLab
Jeff Bagby with the Kairos and Joachim Gerhard with the Kalasan seemed to use just a near 2mH coil on the bass and a second order crossover.
SB Acoustics Satori Monitor
Presumably you filp polarity on a flat baffle.
He made the best of a bad job with the Thrush-CAT in 13L. Surprise that a smaller box worked better.
Thrush-CAT (Satori MW16P-4 with Morel CAT378) – AmpsLab
Jeff Bagby with the Kairos and Joachim Gerhard with the Kalasan seemed to use just a near 2mH coil on the bass and a second order crossover.
SB Acoustics Satori Monitor
Presumably you filp polarity on a flat baffle.
The CAW634 woofer I felt was very benign in the mids, like something was missing. It has the surround dip a lot of 6-7" midbasses have- including the 7" Satori line. I did not miss it as badly in the Satori drivers, but the effect is still there.
Wolf
Wolf
I disconnected the 'upgraded crossover' and connected the ORIGINAL crossover, I verified it's exact as the schematic.
It's still has boomy bass, and it barks when playing loud.
My cabinet was 1 cm deeper (not the baffle) because I upgraded to coil foil inductors and they are HUGE. I guess this 1 cm makes the woofer go crazy. I did a deeper cabinet after checking with Jeff it should be OK.
🙁
It's still has boomy bass, and it barks when playing loud.
My cabinet was 1 cm deeper (not the baffle) because I upgraded to coil foil inductors and they are HUGE. I guess this 1 cm makes the woofer go crazy. I did a deeper cabinet after checking with Jeff it should be OK.
🙁
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@Ita0101
I suggest trying 2 things.
1 - Powering the woofer only from the amp at normal levels. If it sounds bad its the woofer problem. If this is ok then move on to
2 - Connect only the woofer in the cabinet bypassing the crossover - if it sounds bad, there's an issue with the cabinet.
The kind of distortion should not be happening even if the cabinet is smaller or later by a few inches/cm.
I suggest trying 2 things.
1 - Powering the woofer only from the amp at normal levels. If it sounds bad its the woofer problem. If this is ok then move on to
2 - Connect only the woofer in the cabinet bypassing the crossover - if it sounds bad, there's an issue with the cabinet.
The kind of distortion should not be happening even if the cabinet is smaller or later by a few inches/cm.
Ok
Both SB drivers show the problem
The Xover has been checked and replaced by another: no effect
The enclosure is about as the design should be
The tuning of the reflex system hasn’t been checked yet
The amp has been exchanged: no effect
The problem isn’t there with comparable Focal speakers (the Kanta’s don’t seem to be very low tuned)
The source signal characteristics (wrt possible equalization) are as yet unknown
I (still) think there is some loud and low frequency component in the signal that excites the woofer under it’s tuning frequency. Or above, possibly the enclosure/reflex port is misaligned. Chances of two faulty woofers are not that big.
Both SB drivers show the problem
The Xover has been checked and replaced by another: no effect
The enclosure is about as the design should be
The tuning of the reflex system hasn’t been checked yet
The amp has been exchanged: no effect
The problem isn’t there with comparable Focal speakers (the Kanta’s don’t seem to be very low tuned)
The source signal characteristics (wrt possible equalization) are as yet unknown
I (still) think there is some loud and low frequency component in the signal that excites the woofer under it’s tuning frequency. Or above, possibly the enclosure/reflex port is misaligned. Chances of two faulty woofers are not that big.
That is correct, in the video is clearly visible the cone makes way too high excursions. Below the tuning frequency the cone can move freely in a Helmholtz resonator (bassreflex) and that's exactly the problem here. Since the frequencies below fb are that low in level you can't hear them anyway, just use a lowcut/subsonic filter on it (and don't ever +EQ below the fb!). You'll be able to play louder without distortion, hear less distortion in the midrange and more details will be audible.
1 - Powering the woofer only from the amp at normal levels. If it sounds bad its the woofer problem. If this is ok then move on to
Sorry if i wasnt clear about the above, i meant REMOVE the woofer from the cabinet and power direct to the amplifier to see if there's any issues
Sorry if i wasnt clear about the above, i meant REMOVE the woofer from the cabinet and power direct to the amplifier to see if there's any issues
Experienced that recently with a Neurochrome 3886DR with a SB17NAC (Fb=36Hz) speaker. Music with low frequencies, maybe around 35-45Hz, would make the woofer excursion go nuts with very little control. None of the other amps (even LM3886 based ones) does this. I don't know the damping factor on the 3886DR or whether it makes a difference.
I've moved the amp onto other duties with speakers with much higher Fb.
Itamar,
Cone over-excursion is usually due to playing too loud or playing below the tuning frequency. Clearly it's not your amp or the music, and you've tried it on other speakers and amps. That song that you linked to is Get Lucky by Daft Punk, and isn't overly difficult to play.
But it's hard to troubleshoot without some tools.
Do you have a multimeter? You could check the tuning frequency using this method:
The Subwoofer DIY Page - Box-Building FAQ
section 1.03
And use a tone generator via:
Custom Sine Tones | Audio Test File Generator
or NCH Tone Generator
To see if your port tuning is correct, according the Aldephos spec, or which frequency is aggravating the woofer.
Cone over-excursion is usually due to playing too loud or playing below the tuning frequency. Clearly it's not your amp or the music, and you've tried it on other speakers and amps. That song that you linked to is Get Lucky by Daft Punk, and isn't overly difficult to play.
But it's hard to troubleshoot without some tools.
Do you have a multimeter? You could check the tuning frequency using this method:
The Subwoofer DIY Page - Box-Building FAQ
section 1.03
And use a tone generator via:
Custom Sine Tones | Audio Test File Generator
or NCH Tone Generator
To see if your port tuning is correct, according the Aldephos spec, or which frequency is aggravating the woofer.