Now that the horn project has been concluded and abandoned, the quest for new adventures in low frequency continues.
Browsing around, I came across this 15" Dayton Woofer:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-468
Some simulations showed impressive output down to 20 Hz in a 220L vented enclosure, and even in a closed box of "only" 160L, the -3dB point was around 30 Hz.
Does anybody have practical experience with this particular driver in any application??
Browsing around, I came across this 15" Dayton Woofer:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-468
Some simulations showed impressive output down to 20 Hz in a 220L vented enclosure, and even in a closed box of "only" 160L, the -3dB point was around 30 Hz.
Does anybody have practical experience with this particular driver in any application??
A guy recently blew a couple of these when tuning @18hz and using 500w /boost, as I understand.
The story is somewhere on the PE board, dated Jan.
The story is somewhere on the PE board, dated Jan.
Well, 500 W and 18 Hz + boost you say?
According to the simulations I made in WinISD, that would proably take you safely beyond the point of no return (in more than one sense) both in terms of excursion and thermal VC loading, so small surprise!
According to the simulations I made in WinISD, that would proably take you safely beyond the point of no return (in more than one sense) both in terms of excursion and thermal VC loading, so small surprise!
It was part of a larger thread on that driver. Seems a lot of folks like it vented and tuned low for HT. I did not read it close because it was not what I was searching for. Just amazed.
dayton subs
a friend of mine is running four ,each driver in a sealed 3 cubic feet box .
he is driving it with a adcom 4 ch amp , he gets 111 db at 20 hz .
He built the box from win isd .
a friend of mine is running four ,each driver in a sealed 3 cubic feet box .
he is driving it with a adcom 4 ch amp , he gets 111 db at 20 hz .
He built the box from win isd .
Wow.. 111 dB and 20 Hz!
Must say that 3 cubic feet is not a huge box size, was there a lot of EQ involved?
The box size I have calculated when playing around ends up at about 160 L for an -3 dB of 30 Hz.
Have been thinking about building a pair of vented subs with the Peerless XXSL 12" alu-woofers which should reach 20 Hz, but then again, a Dayton 15" in a closed box will have much better group delay..
I guess the big question is really how big the difference will be in sonic quality..
Must say that 3 cubic feet is not a huge box size, was there a lot of EQ involved?
The box size I have calculated when playing around ends up at about 160 L for an -3 dB of 30 Hz.
Have been thinking about building a pair of vented subs with the Peerless XXSL 12" alu-woofers which should reach 20 Hz, but then again, a Dayton 15" in a closed box will have much better group delay..
I guess the big question is really how big the difference will be in sonic quality..
Hi Elbert,Elbert said:
what a coincidence! About two years ago I was standing almost at the same crossroad...
After a lot of simulations I decided on Dayton RSS390HF-4 15"... and I'm very satisfied.
I push them with Hypex 400 (later maybe with 700) from 20 to about 70 Hz (f3) in 75 L (netto) sealed box.
Are you sure that you need two of them?
If you need any further info you're welcome!
Cheers,
to elbert post # 6
His current eq type is a audessy .
Remember it is 4x15" woofers, I think his adcom is a 4x200 watt .
I found all ported subs need some help or must have a subsonic filter .
What the audessy can do is not only fix the sub cabinet size but helps room problems too .
His current eq type is a audessy .
Remember it is 4x15" woofers, I think his adcom is a 4x200 watt .
I found all ported subs need some help or must have a subsonic filter .
What the audessy can do is not only fix the sub cabinet size but helps room problems too .
Ah!
Good to hear about some experiences!
If I go for the Dayton 15", I'll probably run a larger cabinet than 75-80L, more like 160 in order to get the benefits of good group-delay and not use up to much headroom with EQ correction.
I guess one unit would do, but there are a couple of reasons I'll probably go for stereo-subs:
1:
Better distribution of room modes, two LF sources in one rom (at different locations) will increase the number of modes, thereby allowing a better averaging effects.
2:
Stereo-subs allow higher X-over point meaning that I can run small stereo-speakers at realistic levels without killing them with excessive cone-excursion.
Would be interesting to know if anybody has tried these drivers (or comparable) in both vented and closed boxes and what the listening experience was? Is the difference in group delay noticeable? and is the closed box set-up worth the trade off in LF extension in any way?
Good to hear about some experiences!
If I go for the Dayton 15", I'll probably run a larger cabinet than 75-80L, more like 160 in order to get the benefits of good group-delay and not use up to much headroom with EQ correction.
I guess one unit would do, but there are a couple of reasons I'll probably go for stereo-subs:
1:
Better distribution of room modes, two LF sources in one rom (at different locations) will increase the number of modes, thereby allowing a better averaging effects.
2:
Stereo-subs allow higher X-over point meaning that I can run small stereo-speakers at realistic levels without killing them with excessive cone-excursion.
Would be interesting to know if anybody has tried these drivers (or comparable) in both vented and closed boxes and what the listening experience was? Is the difference in group delay noticeable? and is the closed box set-up worth the trade off in LF extension in any way?
Hi Elbert,Elbert said:
maybe you can find the answer about your interesting dilemma here: http://www.trueaudio.com/post_010.htm
Cheers,
Elbert said:
Reason #3 a second driver adds 6 db , and if you buy a externall amp you may have a spare channel , my friend tried the dayton rss by running them on winisd , ported took less power but that driver being in 3 cubic only needs 200 watts , plus the sealed response curve was smoother .
Try winisd its a free program !
Very interesting link to that article on group delay and phase!
Going by the theory described in there, it would seem that the greater group delay of vented design is not necessarily that significant.
Too bad the thread of that link didn't have more in terms of subjective listening experience.
Yes, I have WinISD, and its a fantastic piece of software, especially considering its for free! Been playing along with it quite a lot actually.
And that brings me back to closed box volume. I assume that WinISD calculates an empty box, but since box stuffing can significantly increase the effective compliance (effective volume) of a closed box, I guess it feasible to get away with a physically smaller box for the Dayton 15" drivers than the calculations alone calls for.
A good vented design for these drivers would require a volume of about 220 L, and that's sort of starting to get a bit large, especially for two. Having said that the system would then be linear down to 20 Hz!
On the other side, -3dB at 30 Hz from, say, a 120 L closed box is still very respectable, and with some added room gain it may perhaps be perfectly ok?
hmmm...
Going by the theory described in there, it would seem that the greater group delay of vented design is not necessarily that significant.
Too bad the thread of that link didn't have more in terms of subjective listening experience.
Yes, I have WinISD, and its a fantastic piece of software, especially considering its for free! Been playing along with it quite a lot actually.
And that brings me back to closed box volume. I assume that WinISD calculates an empty box, but since box stuffing can significantly increase the effective compliance (effective volume) of a closed box, I guess it feasible to get away with a physically smaller box for the Dayton 15" drivers than the calculations alone calls for.
A good vented design for these drivers would require a volume of about 220 L, and that's sort of starting to get a bit large, especially for two. Having said that the system would then be linear down to 20 Hz!
On the other side, -3dB at 30 Hz from, say, a 120 L closed box is still very respectable, and with some added room gain it may perhaps be perfectly ok?
hmmm...
I recently finished a sub using this driver in a sealed cabinet of around 160L. I have a Reckhorn A-402 which works very well with the sub. My main speakers are Rogers LS5/9 driven by a UCD180HG power amp
To optimise the system I borrowed a Behringer DEQ2496 and ECM8000 mic to measure the system response at various positions around the room.
Without the sub, my speakers reach down to around 40Hz in-room. I built the sub to give me 20-40Hz - it does this easily.
I wouldn't hesitate to recommend this driver in a large sealed box. It gets to 20Hz in-room with very little effort yet sounds tight and tuneful all the way up to >200Hz.
To optimise the system I borrowed a Behringer DEQ2496 and ECM8000 mic to measure the system response at various positions around the room.
Without the sub, my speakers reach down to around 40Hz in-room. I built the sub to give me 20-40Hz - it does this easily.
I wouldn't hesitate to recommend this driver in a large sealed box. It gets to 20Hz in-room with very little effort yet sounds tight and tuneful all the way up to >200Hz.
Ah! How perfect, an application very close to what I'm contemplating!
And with both measurements and listening impressions to back up a recommendation, most promising!
If 20 Hz is no problem and the sound is "tight" as well, this is really starting to sound interresting.
By the way, what sort of stuffing did you use for the boxes?
And with both measurements and listening impressions to back up a recommendation, most promising!
If 20 Hz is no problem and the sound is "tight" as well, this is really starting to sound interresting.
By the way, what sort of stuffing did you use for the boxes?
No stuffing used so far, as I have only used the sub for 20-40Hz (stuffing wouldn't do much at these frequencies, as I understand it).
When I first powered up the sub I adjusted the master level on the Reckhorn so that the sub and main speakers produced the same output at 50Hz. When I then measured the subs output at 20Hz, it was 9dB higher than the output at 50Hz! (my room is approx 3.5x3.3x5.5m).
I wouldn't worry about getting to 20Hz if your room is similar size to my own.
When I first powered up the sub I adjusted the master level on the Reckhorn so that the sub and main speakers produced the same output at 50Hz. When I then measured the subs output at 20Hz, it was 9dB higher than the output at 50Hz! (my room is approx 3.5x3.3x5.5m).
I wouldn't worry about getting to 20Hz if your room is similar size to my own.
Wow, seems like the effects of room gain is not to be underestimated!
Considering your findings, it would seem that building vented enclosures linear down to 20 Hz would be totally necessary.
Regarding stuffing, for damping standing waves and resonances I agree that the effect will probably be minimal at the very low frequencies we are talking about here.
But from what I've read, adding damping material to a closed box will increase the acoustic compliance, meaning that the system Q will drop.
According to my simulations, a 160 L un-stuffed box will give a Q of about 0,7 or a "max flat amplitude response" as it is allso known as.
This should mean that a smaller box with stuffing may give the same response as the larger but un-stuffed 160 L box.
the other way around, if you stuff your box, it should take you closer to a Q 0,5 (max flat delay response).
What is the output level like?
And does it play clean even when loud?
Considering your findings, it would seem that building vented enclosures linear down to 20 Hz would be totally necessary.
Regarding stuffing, for damping standing waves and resonances I agree that the effect will probably be minimal at the very low frequencies we are talking about here.
But from what I've read, adding damping material to a closed box will increase the acoustic compliance, meaning that the system Q will drop.
According to my simulations, a 160 L un-stuffed box will give a Q of about 0,7 or a "max flat amplitude response" as it is allso known as.
This should mean that a smaller box with stuffing may give the same response as the larger but un-stuffed 160 L box.
the other way around, if you stuff your box, it should take you closer to a Q 0,5 (max flat delay response).
What is the output level like?
And does it play clean even when loud?
I always planned on trying stuffing but was so happy with the sub without that I haven't yet felt the need. I designed the sub to be clean and deep and primarily suitable for music. The sub and amp are more than sufficient for my room and listening volume range - even when I have cranked up the volume as loud as I could ever want there is no sign that the sub/amp are close to their limits (even with heavy dubstep).
That really sounds convincing!
Please post if you decide to chuck in some stuffing, would be really interesting to know what sort of audible impact that would make.
Do you have any pictures to post by the way?
Please post if you decide to chuck in some stuffing, would be really interesting to know what sort of audible impact that would make.
Do you have any pictures to post by the way?
Ah, I see!
No rush though, won't be kicking of this project tomorrow anyway!
But thanks a lot for the input, that certainly removed some of my doubts.
After all, a pair of these drivers and the associated carpentry and amplification represents a bit of an investment, so it is always good to get some additional input before moving it on!🙂
No rush though, won't be kicking of this project tomorrow anyway!
But thanks a lot for the input, that certainly removed some of my doubts.
After all, a pair of these drivers and the associated carpentry and amplification represents a bit of an investment, so it is always good to get some additional input before moving it on!🙂
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