Hello Friends,
This is my first post here. I'am a complete newbie when it comes to diy loudspeakers, so please bear with me. Recently, I have attempted a project in winisd using a 15" driver by the name Ahuja AS-15 X200. The T/S Parameters for the driver are as in the image along with frequency response graph. The box volume is 86 litres with tuning frequency as 58Hz, however the -3.0Db point of the box is at 51Hz. The Ports are 10.2cm in diameter and there will be two of them. Looking at the FR graph there is huge peak from 50hz to around 70hz. So Friends, looking at the graph how do you think this box would sound? Thank you very much.
This is my first post here. I'am a complete newbie when it comes to diy loudspeakers, so please bear with me. Recently, I have attempted a project in winisd using a 15" driver by the name Ahuja AS-15 X200. The T/S Parameters for the driver are as in the image along with frequency response graph. The box volume is 86 litres with tuning frequency as 58Hz, however the -3.0Db point of the box is at 51Hz. The Ports are 10.2cm in diameter and there will be two of them. Looking at the FR graph there is huge peak from 50hz to around 70hz. So Friends, looking at the graph how do you think this box would sound? Thank you very much.
Attachments
Tricky question.
Depending on your room size, the proposed speaker location within the room, and the absorptive materials in the room it could be enjoyable, or fulsome or completely overblown. Some would add a Sub woofer for the very lowest frequencies.
Double check your parameter's and verify correct units are used and see if you can fill in a few more parameters just to make sure you have captured as much data as possible. What does the impedance curve show two equal amplitude peaks either side of the box frequency?
Try running the model for sealed with a Q or 0.5, and maybe 0.8 to see how it behaves and lessens the bass hump. Also try the vented SBB4 alignment and see if that gives less of a hump, but falling off a a bit quicker.
15" bass drivers are not something I play with, but there are lost here who should know what to try next, or give their views.
Depending on your room size, the proposed speaker location within the room, and the absorptive materials in the room it could be enjoyable, or fulsome or completely overblown. Some would add a Sub woofer for the very lowest frequencies.
Double check your parameter's and verify correct units are used and see if you can fill in a few more parameters just to make sure you have captured as much data as possible. What does the impedance curve show two equal amplitude peaks either side of the box frequency?
Try running the model for sealed with a Q or 0.5, and maybe 0.8 to see how it behaves and lessens the bass hump. Also try the vented SBB4 alignment and see if that gives less of a hump, but falling off a a bit quicker.
15" bass drivers are not something I play with, but there are lost here who should know what to try next, or give their views.
Unfortunately this driver is not well suited for bass reflex cabinets as its Qts value is 0.55. This high Qts is prohibiting a flat response leading to a huge bump in the frequency response. In most cases this will result in a boomy 'one note' bass. Furthermore, your cabinet is too small - at least twice the volume would be required to achieve a more flat response. Closing the ports (to get a CB) will result in an overall Qts of approx. 0.82 which will be reasonable flat but the -3dB frequency will be even higher (somewhere around 65 to 68 Hz)
Overall, this driver due to its TS parameters is best for transmission line cabinets or open baffle speakers.
Sorry for having no better answer.
Overall, this driver due to its TS parameters is best for transmission line cabinets or open baffle speakers.
Sorry for having no better answer.
I think the peak you're mentioning maybe necessary if this is for an outdoor application, as the Ahuja PA speaker you're referring to does not seem to have a lot of excursion capability. However, if indoors, then the hump may not be necessary (maybe EQed out), because of room gain that results. However, it still depends on the room dimensions. Please check the following link for finding out your room modes.
amroc - THE Room Mode Calculator
This speaker is routinely used in vented PA boxes and I don't think I need to tell you how they sound! But inside a room the story could be different altogether. If it's an outdoor application and you need great sound, then I would recommend (within the Ahuja brand) the L15-MB500 that has a 4-inch voice coil and 8mm excursion.
amroc - THE Room Mode Calculator
This speaker is routinely used in vented PA boxes and I don't think I need to tell you how they sound! But inside a room the story could be different altogether. If it's an outdoor application and you need great sound, then I would recommend (within the Ahuja brand) the L15-MB500 that has a 4-inch voice coil and 8mm excursion.
Last edited:
It's not so much of a mistake the Qts being higher than what's considered optimal, it's too small of a volume with too high of a tuning.
Right, a T/S max flat with a bit of wiring resistance requires ~381 L tuned to ~32 Hz, so a better choice overall to EQ a HIFI/HT app if the reduced LF power handling is offset enough by room gain or try a higher tuning with differing EQ as required and use the 'click' test [impulse response] to damp any vent peaking [boominess]: Click Test | GM210 | Flickr
Thanks so much for the reply guys. I was just wondering, the driver in question is just within xmax 3.5mm at 80 watts inside this box. I've read somewhere that the 50-70hz bump is the "disco" bump and should be good for old dance music and electronic music and this box has a huge bump!(I think its almost 2.5db at 62hz) I also read that a driver that has reached or exceeded its xmax will be boomy. So in practice wouldn't this box give a tight and powerful slam?Please correct me if im wrong.
You're welcome!
Dunno, from the ~ early days up to ~2000, prosound was ~ flat from 300 - 80 Hz, decaying 4th order to 40 Hz, i.e. reflex cabs tuned to ~45 Hz with ~56 Hz tuning for 'slam', so the majority of the vinyl, etc., HIFI speakers I designed and/or built were tuned in the 40s with party speakers in the 50s and sometimes 60s and went backwards as CDs, DVDs, etc., kept pushing the LF cutoff ever lower to the point now that only sealed can go low enough for some movies.
Regardless, 2.5 dB is just barely audible unless a room mode amplifies it enough, so for your music, may want more.
'Boomy' is when there's a prominent mid bass hump due to a truly under-damped alignment or inductance rise due to VC heating when driven too hard for too long even if not driven to Xmax like can happen reproducing a low note pipe organ sustain or electronic tone for the length of a song/whatever.
Exceeding Xmax enough to be audible is plain distorted in that the signal gets delayed, making it increasing out of sync with the higher frequencies and at some point its mechanicals start audibly 'complaining'.
Anyway, 'tight' 'slam' with this driver would in theory be a classic alignment = ~ 80 L tuned to actual Fs with at least a 6" vent to get the historically desired 'bump' plus it can handle its full 200 W rating down to 40 Hz, but if the specs aren't pretty accurate it might take a lot of EQ to get it right in room.
Dunno, from the ~ early days up to ~2000, prosound was ~ flat from 300 - 80 Hz, decaying 4th order to 40 Hz, i.e. reflex cabs tuned to ~45 Hz with ~56 Hz tuning for 'slam', so the majority of the vinyl, etc., HIFI speakers I designed and/or built were tuned in the 40s with party speakers in the 50s and sometimes 60s and went backwards as CDs, DVDs, etc., kept pushing the LF cutoff ever lower to the point now that only sealed can go low enough for some movies.
Regardless, 2.5 dB is just barely audible unless a room mode amplifies it enough, so for your music, may want more.
'Boomy' is when there's a prominent mid bass hump due to a truly under-damped alignment or inductance rise due to VC heating when driven too hard for too long even if not driven to Xmax like can happen reproducing a low note pipe organ sustain or electronic tone for the length of a song/whatever.
Exceeding Xmax enough to be audible is plain distorted in that the signal gets delayed, making it increasing out of sync with the higher frequencies and at some point its mechanicals start audibly 'complaining'.
Anyway, 'tight' 'slam' with this driver would in theory be a classic alignment = ~ 80 L tuned to actual Fs with at least a 6" vent to get the historically desired 'bump' plus it can handle its full 200 W rating down to 40 Hz, but if the specs aren't pretty accurate it might take a lot of EQ to get it right in room.
Hi,
You are not wrong about the 60hz bump on 'disco'.
It is something that was extensively used in my days as a dj ( circa 95 to 05) into electronic music ( D&B scene). But we didn't relyed on loudspeakers for that to happen ( it's not totally true as the loudspeakers had to cope with it ( the boost) but the loudspeakers/ soundsystem was meant to be more or less flat profile by themself, thus oversized as GM said you will need more than 2,5db... up to 6/9db ime).
So we used electronic circuits for this ( in the crew i evolved in, but it was common from what i've seen): we choose a Freevox desk because (not only as it have pristine sound, usable eq and functionality and was sturdy built...) it incorporated this function called 'Disco sound' which is a kind of 'bell' boost centered on 60hz ( but not only a bell eq, it compress a bit the signal giving it increased feeling of punch).
We weren't the only to use that ( underground scene): i know some famous 'french touch' 's dj imposed this desk on some ibiza's club.
Anyway if you are interested in implementing this function it can be easily built on a vero board ( you'll need a good +/- 15v psu too, and maybe implement a THAT 1246/1646 combo if you need balanced input/output, as is it should be ok ).
You'll find the circuit page 9 on the lower right of the schematic. It is based upon U6A/B and include parts from c107/c131 to the outputs cn4/5.
https://medias.audiofanzine.com/files/freevox-dj4-schema-470606.pdf
The switch enable the process, the knob the intensity ( gain up to +12db).
Total cost should be less than 10euros for a stereo circuit ( without psu, connectors, case)...
With the kind of music i play(ed) mid course was usually ok on small soundsystems too much on 'big' ones i played, 1/3 the course was usually better.
You are not wrong about the 60hz bump on 'disco'.
It is something that was extensively used in my days as a dj ( circa 95 to 05) into electronic music ( D&B scene). But we didn't relyed on loudspeakers for that to happen ( it's not totally true as the loudspeakers had to cope with it ( the boost) but the loudspeakers/ soundsystem was meant to be more or less flat profile by themself, thus oversized as GM said you will need more than 2,5db... up to 6/9db ime).
So we used electronic circuits for this ( in the crew i evolved in, but it was common from what i've seen): we choose a Freevox desk because (not only as it have pristine sound, usable eq and functionality and was sturdy built...) it incorporated this function called 'Disco sound' which is a kind of 'bell' boost centered on 60hz ( but not only a bell eq, it compress a bit the signal giving it increased feeling of punch).
We weren't the only to use that ( underground scene): i know some famous 'french touch' 's dj imposed this desk on some ibiza's club.
Anyway if you are interested in implementing this function it can be easily built on a vero board ( you'll need a good +/- 15v psu too, and maybe implement a THAT 1246/1646 combo if you need balanced input/output, as is it should be ok ).
You'll find the circuit page 9 on the lower right of the schematic. It is based upon U6A/B and include parts from c107/c131 to the outputs cn4/5.
https://medias.audiofanzine.com/files/freevox-dj4-schema-470606.pdf
The switch enable the process, the knob the intensity ( gain up to +12db).
Total cost should be less than 10euros for a stereo circuit ( without psu, connectors, case)...
With the kind of music i play(ed) mid course was usually ok on small soundsystems too much on 'big' ones i played, 1/3 the course was usually better.
Last edited:
Hi GM,
As i previously said the max i would have used it is midway through the pot range so +6db at max on small systems.
On big ones i never used more than 4db, but anyway with this kind of system you can't usually apply as much cut/boost as with smaller ones ( i talk about chanel eq, the tools used by dj, not technicals, this treatment i consider to be a dj tool too).
I don't know the Q of the circuit i talk about and i suspect it change with amount ( as well as the compression effect) but i'll measure it ( i still own and use one of this desk) and let you know.
I suppose one could easily simulate the circuit too.
But well, yes we were commonly abusing wrt to low end in comparison to rock. We mostly played outdoors too that may explain why it was such high settings ( and because of the style requirements too), indoor i was less heavy handed ( 4db max).
As i previously said the max i would have used it is midway through the pot range so +6db at max on small systems.
On big ones i never used more than 4db, but anyway with this kind of system you can't usually apply as much cut/boost as with smaller ones ( i talk about chanel eq, the tools used by dj, not technicals, this treatment i consider to be a dj tool too).
I don't know the Q of the circuit i talk about and i suspect it change with amount ( as well as the compression effect) but i'll measure it ( i still own and use one of this desk) and let you know.
I suppose one could easily simulate the circuit too.
But well, yes we were commonly abusing wrt to low end in comparison to rock. We mostly played outdoors too that may explain why it was such high settings ( and because of the style requirements too), indoor i was less heavy handed ( 4db max).
Last edited:
Good to know, thanks! If I'm going help with speaker designs for modern music 'tastes', guess I need to update myself somewhat.
I've read comments from Ivan ( Which work or worked for Danley) on another forum ( prosoundweb?) about the big modern EDM events ( Coachella or this kind of festivals) where the final eq profile was 'customer designed': they allowed the organiser/planer of the event to tune the whole system to 'taste' as outcome some 9 to 12db low shelf and smiley profile iirc.
The amount of sub box and amp to power things like that is beyond reason.
I'm kind of 'old school' regarding sound systems and EDM : youngsters in bassmusic/dubstep goes deep with high spl. Think recent Meyer subs going down 14hz. Guy like BassNectar are notorious for live events with sub in the ~10hz at crazy spl.
I missed this whole movement though as i had to make a choice between day job and party for my ears health. Hence 'old school'. I'm pleased when it's low distortion and well setup. Extreme bandwidth can be real fun but if 30hz/10khz is nice and don't make ears bleed i'm more than happy.
The amount of sub box and amp to power things like that is beyond reason.
I'm kind of 'old school' regarding sound systems and EDM : youngsters in bassmusic/dubstep goes deep with high spl. Think recent Meyer subs going down 14hz. Guy like BassNectar are notorious for live events with sub in the ~10hz at crazy spl.
I missed this whole movement though as i had to make a choice between day job and party for my ears health. Hence 'old school'. I'm pleased when it's low distortion and well setup. Extreme bandwidth can be real fun but if 30hz/10khz is nice and don't make ears bleed i'm more than happy.
Last edited:
Sheesh! I'll leave these to the Paraflex community since SQ isn't a primary goal.
Agreed, except for Covid I try to get an annual dose of Imax and this: First Presbyterian Church of Atlanta - AGO Atlanta
Agreed, except for Covid I try to get an annual dose of Imax and this: First Presbyterian Church of Atlanta - AGO Atlanta
Thanks again for the replies.What I want to know is with the graphs and details I have posted, if I were to use this box indoors with some bass boosting how would it likely sound?
Last edited:
You're welcome!
Well, using Hornresp and adding some inductance [Le] that should have been part of the specs, the actual designed in 'bump' is more like +6 dB, which in a typical room is car boombox sounding to me, but I assume DSP can reshape it or boost the bandwidth [BW] above it to flatten it in room, or boost it if wanting even more 'boom'.
Well, using Hornresp and adding some inductance [Le] that should have been part of the specs, the actual designed in 'bump' is more like +6 dB, which in a typical room is car boombox sounding to me, but I assume DSP can reshape it or boost the bandwidth [BW] above it to flatten it in room, or boost it if wanting even more 'boom'.