Hey all, new to sub side here (built all sorts of Class A, AB, Tube, SS amps and ESLs) and looking for some suggestions... I am a bit Bass spoiled as I had a pair of Magnepan Tympani IVas that were incredible in the bass and upper bass region. Never was much of a bass guy until I had those speakers...simply breathtaking...
So here is the deal...I have a nice pair of Martin Logan CLS Electrostats (and a second pair of CLSIIa) panels that I built interfaces for. Sounds perfect for my tastes and size room.
Now I want to add a pair of homebrew subwoofers.
I have a DCX2496 (for biamp) and an Icepower 1000ASP stereo amp dedicated to drive the subs, and a Krell Clone I built to run the CLS at 125hz and up, sub from 30 to 125hz. The DCX2496 can be used to tweak the various XO slopes and the phase, so I should be ok here...
Now I have a stand that the CLS panels sit on top of that would be ideal for a Sub enclosure - has exactly 2.5 cu ft of volume I could enclose. I want a sealed enclosure, not ported as I believe its is more musical.
I was looking for a forward firing pair of 8" subwoofer drivers each side. I could do a single, much larger downfiring driver with same volume, but think the midbass would be best forward firing....
I know this is not a whole lot of info, but a starting point...and advice on a single or dual 8" driver that would be good in a 2.5cu ft volume and be able to faithfully reproduce 125hz - 30hz at respectable volume (not ear bleed loud)??
So here is the deal...I have a nice pair of Martin Logan CLS Electrostats (and a second pair of CLSIIa) panels that I built interfaces for. Sounds perfect for my tastes and size room.
Now I want to add a pair of homebrew subwoofers.
I have a DCX2496 (for biamp) and an Icepower 1000ASP stereo amp dedicated to drive the subs, and a Krell Clone I built to run the CLS at 125hz and up, sub from 30 to 125hz. The DCX2496 can be used to tweak the various XO slopes and the phase, so I should be ok here...
Now I have a stand that the CLS panels sit on top of that would be ideal for a Sub enclosure - has exactly 2.5 cu ft of volume I could enclose. I want a sealed enclosure, not ported as I believe its is more musical.
I was looking for a forward firing pair of 8" subwoofer drivers each side. I could do a single, much larger downfiring driver with same volume, but think the midbass would be best forward firing....
I know this is not a whole lot of info, but a starting point...and advice on a single or dual 8" driver that would be good in a 2.5cu ft volume and be able to faithfully reproduce 125hz - 30hz at respectable volume (not ear bleed loud)??
For sealed, 2.5 cu ft is right in the range for a 12 to 15" driver or a pair of 10s. Choose one with a very low Fs, say in the lower twenty hertz or even upper teens. Use WinISD or some modeling software to be sure the driver fits the volume you want. Keep Qtc around .7 or less for a nice slow roll off that is easier to equalize if needed.
Use a pair in each enclosure (4 total)??
Price Range? Oh hell, I don't know...$500 - $600?
At 12", it would force me to use downfiring - is this ok?? Preferred??
Is the Infinity 1260W a Car Sub? Does it matter?
Price Range? Oh hell, I don't know...$500 - $600?
At 12", it would force me to use downfiring - is this ok?? Preferred??
Is the Infinity 1260W a Car Sub? Does it matter?
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Let's see... a pair in each enclosure 4 total... yep
Down firing is fine as long as the driver doesn't sag over time, I don't think any of the suggested drivers will. You can find a formula to calculate sag here.
Car subs are fine as house subs. They are marketed much differently and often times don't provide all the parameters you might want before buying a sub, but they are still just subs. Some of them are very nice.... Some of them are very ugly, but still nice. Some are crap... no different than home audio subs.
At a higher price-point...
Martin Logan, eh? I agree you'll be better off with sealed sub, tuned to a Q of 0.5 to 0.618, those values seem to work the best in most listening rooms.
It's going to be very good (some would say essential) to get "fast" woofers with a high acceleration factor (high Bl, low mmd)... a lot of the recommendations I've read here will sound too slow and sluggish for your 'stats
A pair of ScanSpeak Revelator 18W/8531G-00 7" per enclosure would do the job very nicely. Or perhaps these: ScanSpeak Illuminator 18WU/4741T-00 7"
Along with beng fairly "fast", they also have extended, flat response which makes the crossover easier. Despite their small size, they have tremendous excursion and impact, and fairly low distortion.
However... if you're willing to spend more, then the Rhythmik servo-subs can be a very good option, due to the servo they speed match 'stats a lot better than most anything except for the top-tier full-servo Velodynes.
The BEST option IMO would be to use the Rhyhmik/GR drivers with dedicated servo-amp, as shown here:
Rythmik Audio 12" Servo subwoofer " GR 12" Custom Installation subwoofer
These are open baffle servo-subs which would speed-match exceptionally well, with the added advantage of matching the directivity with the 'stats throughout the bass region. This will make it MUCH easier for you to get a good crossover blend. It would probably be the most transparent and seamless match.
And using the DCX2496 you can implement a special type of "transient perfect" crossover that has some really great qualities: dial in a 4th order Bessel low-pass (80 to 100 Hz) for the subs, a 1st order for the ML's (at 80 to 100Hz), and then dial in the right delay on the ML's (4.7ms for 80Hz, 3.75 ms for 100Hz) to achieve proper phase/time integration. This approach will give you near perfect amplitude/phase/transient response with near-zero time smearing. The audible difference is not subtle.
As for the DCX2496's admittedly not so-great analog section, I recommend you mod it. With Martin Logan's, your ears will thank you for it. Look up ASI-tek, or Scott Sendler's mods, or I can do them also just PM me for more info.
Martin Logan, eh? I agree you'll be better off with sealed sub, tuned to a Q of 0.5 to 0.618, those values seem to work the best in most listening rooms.
It's going to be very good (some would say essential) to get "fast" woofers with a high acceleration factor (high Bl, low mmd)... a lot of the recommendations I've read here will sound too slow and sluggish for your 'stats
A pair of ScanSpeak Revelator 18W/8531G-00 7" per enclosure would do the job very nicely. Or perhaps these: ScanSpeak Illuminator 18WU/4741T-00 7"
Along with beng fairly "fast", they also have extended, flat response which makes the crossover easier. Despite their small size, they have tremendous excursion and impact, and fairly low distortion.
However... if you're willing to spend more, then the Rhythmik servo-subs can be a very good option, due to the servo they speed match 'stats a lot better than most anything except for the top-tier full-servo Velodynes.
The BEST option IMO would be to use the Rhyhmik/GR drivers with dedicated servo-amp, as shown here:
Rythmik Audio 12" Servo subwoofer " GR 12" Custom Installation subwoofer
These are open baffle servo-subs which would speed-match exceptionally well, with the added advantage of matching the directivity with the 'stats throughout the bass region. This will make it MUCH easier for you to get a good crossover blend. It would probably be the most transparent and seamless match.
And using the DCX2496 you can implement a special type of "transient perfect" crossover that has some really great qualities: dial in a 4th order Bessel low-pass (80 to 100 Hz) for the subs, a 1st order for the ML's (at 80 to 100Hz), and then dial in the right delay on the ML's (4.7ms for 80Hz, 3.75 ms for 100Hz) to achieve proper phase/time integration. This approach will give you near perfect amplitude/phase/transient response with near-zero time smearing. The audible difference is not subtle.
As for the DCX2496's admittedly not so-great analog section, I recommend you mod it. With Martin Logan's, your ears will thank you for it. Look up ASI-tek, or Scott Sendler's mods, or I can do them also just PM me for more info.
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Hmm, opinions are all over the board. All seem to agree on sealed...don't really see any need to get under 30hz....and either 10" or 12" but not an array of 8".
I looked into the Rythmic Audio subs and they are nice and pricey (I would want a pair)...
A friends swears by his single Martin Logan Depths (three 8" drivers if I remember correctly), and I read the Kinergetics SW800 was the tried and true match to the CLS', while the Magnepan Tympani IVa Bass Panels were the ultimate match for the CLS...
Like I said, I have the amp and the XO, does anyone still sell passives?
I looked into the Rythmic Audio subs and they are nice and pricey (I would want a pair)...
A friends swears by his single Martin Logan Depths (three 8" drivers if I remember correctly), and I read the Kinergetics SW800 was the tried and true match to the CLS', while the Magnepan Tympani IVa Bass Panels were the ultimate match for the CLS...
Like I said, I have the amp and the XO, does anyone still sell passives?
How large is your room? Cabin gain can be significant in the lower frequencies for small to medium size rooms.
I built a single 15" sub 7 cuft enclosure for a car and it combined almost perfectly with the cabin gain for flat response well under 20Hz without eq, obviously cabin gain will be smaller in a room but still...
I built a single 15" sub 7 cuft enclosure for a car and it combined almost perfectly with the cabin gain for flat response well under 20Hz without eq, obviously cabin gain will be smaller in a room but still...
If you want inexpensive...
but still good..
in a small room like yours you'll get plenty of room gain. Try two of these per side: Dayton Audio RS225-8
In a 2.5 cu.ft. box stuffed w. Dacron Polyfill you should get Fb of 42Hz or so, with box Q about 0.67
This type of response, when associated with room gain should give you extended in-room response down to the low 30's or upper 20's. And with the DCX2496 you can knock out much of the room modes.
Is the ceiling 8 ft tall? If so, plan on knocking down the level near 71Hz, the 10ft lateral will give you a big boost around 50Hz and probably need reducing. The room mode from the 17ft length will boost the bass near 33Hz, so you may not need any boost at all to get flat bass down quite low.
However, the advantage of an open baffle woofer would be that the vertical and lateral modes would be much reduced due to not being excited as much.
but still good..
in a small room like yours you'll get plenty of room gain. Try two of these per side: Dayton Audio RS225-8
In a 2.5 cu.ft. box stuffed w. Dacron Polyfill you should get Fb of 42Hz or so, with box Q about 0.67
This type of response, when associated with room gain should give you extended in-room response down to the low 30's or upper 20's. And with the DCX2496 you can knock out much of the room modes.
Is the ceiling 8 ft tall? If so, plan on knocking down the level near 71Hz, the 10ft lateral will give you a big boost around 50Hz and probably need reducing. The room mode from the 17ft length will boost the bass near 33Hz, so you may not need any boost at all to get flat bass down quite low.
However, the advantage of an open baffle woofer would be that the vertical and lateral modes would be much reduced due to not being excited as much.
Whoops, sorry, it is 18 x 14, and just under 8 foot ceiling.
Wow, I am impressed. I haven't really used the DCX for much other than trying slopes and moving crossover points on a two way biamp - not equalization - so this will be interesting...
Wow, I am impressed. I haven't really used the DCX for much other than trying slopes and moving crossover points on a two way biamp - not equalization - so this will be interesting...
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18 by 14 by 8?
Main modes would be near 31.5Hz (longitudinal), 40.6Hz lateral, and if 8ft ceiling 71Hz vertical
Main modes would be near 31.5Hz (longitudinal), 40.6Hz lateral, and if 8ft ceiling 71Hz vertical
Mod it fer sure
Yeah, the DCX is quite an amazing unit... and it can be a truly audiophile piece when modded. You owe it to yourself to do it, as the quality of the onboard DAC really deserves a better analog section. It can sound really, really stellar, on a par with any DAC in the under 2K range.
Yeah, the DCX is quite an amazing unit... and it can be a truly audiophile piece when modded. You owe it to yourself to do it, as the quality of the onboard DAC really deserves a better analog section. It can sound really, really stellar, on a par with any DAC in the under 2K range.
Hi,
FWIW with twin 8" daytons per side and 2.5 cuft a low tuned vented
alignment will give better results than sealed regarding deep bass and
maximum SPL levels, shown is a very fuss free alignment very suited
to room gain that will simply dig deeper than a sealed arrangement.
Eyeopenly different capabilities between 20Hz and 30Hz.
rgds, sreten.
FWIW with twin 8" daytons per side and 2.5 cuft a low tuned vented
alignment will give better results than sealed regarding deep bass and
maximum SPL levels, shown is a very fuss free alignment very suited
to room gain that will simply dig deeper than a sealed arrangement.
Eyeopenly different capabilities between 20Hz and 30Hz.
rgds, sreten.
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Looking at a pair of NHT 1-11-084-011 8" Woofer...am I kidding myself??
Reve= 5.500 Ohm
Fo= 32.240 Hz
Sd= 21.739m M2
Krm= 1.060m Ohm
Erm= 0.899
Kxm=55.063m H
Exm= 0.521
Vas=63.487 Ltr
Cms= 946.082u M/N
Mmd= 23.916m Kg
Mms= 25.759g
BL= 8.919 TM
Qms= 1.935
Qes= 0.361
Qts= 0.304
No= 0.570%
SPLo= 89.579 dB
Reve= 5.500 Ohm
Fo= 32.240 Hz
Sd= 21.739m M2
Krm= 1.060m Ohm
Erm= 0.899
Kxm=55.063m H
Exm= 0.521
Vas=63.487 Ltr
Cms= 946.082u M/N
Mmd= 23.916m Kg
Mms= 25.759g
BL= 8.919 TM
Qms= 1.935
Qes= 0.361
Qts= 0.304
No= 0.570%
SPLo= 89.579 dB
That looks like a good option. However, if used without any EQ, the earlier rolloff of the sealed enclosure may mate better with the room. Oft-times a truly extended sub with bass into the low 20's will sound too heavy due to the room modes.
But the beauty of what you're proposing is that with the twin Dayton's one could build the ported version and have the option of running it that way, or to stuff the port to obtain a quasi sealed response, a case of having good cake and eating too.
So yeah, I'd be a proponent of the twin 8's over almost any 10" or 12"
But given that there is some great EQ capability in the DCX2496, I'd like a pair of twin 15's in OB even better...
Yes, there's a usually a tradeoff, losing some of the bass below 40 Hz, but the clarity from 40 to 200 Hz makes it a very appealing option... and when you factor in that in this application the main speakers are di-poles, and that the directionality patterns would match ideally, maybe this would be the better option.
Having done something similar using twin Eminence Alpha 15a's, and (when properly eq'd !!) the bass is really quite astonishing in its quickness, impact and tonality. I would take this option over the sealed or ported or even a really good t-line for sheer musicality and speed, and given that the OP is using Martin-Logans methinks this would be the best match when $$ are a consideration.
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