2x2245 coffin sised cabinets

[gassman_67]

Hello all, my first post here.I have built a tower speaker with twin 2245, twin 2118, an ATC domed mid and Scanspeak 9900 tweeter, my issue is lack of bottom end,they are on a passive crossover and at 160hz. For power on this setup, a Krell 750 mono, each cabinet is 80x22x30, with 4 6" precision ports (10.25" each). I'd lke to get a bit more out the 18's
thanks!

[Lee in Montreal]

Hold on. You have TWO 2245 woofers and you don't have enough bottom end? Is that what I should understand? :eek:

A single 2245 is enough to energize a room.

Are you sure those are real 2245 (2245 cone kit)? What volume per woofer?

[Allanvh5150]

The ports look quite a lot smaller than 6''. Can you clarify?

Allan.

[Ed Zeppeli]

.

Are you sure those are real 2245 (2245 cone kit)? What volume per woofer?


Yeah. Those cones look.....shiny.

[audiomagnate]

Yeah. Those cones look.....shiny.

Yeah, what's up with the shiny cones and the tiny ports? For two 2245s you need a box of at least 16 ft3 with proper ports. Four 2245s should not result in a bass shy system, something is terribly wrong. Plus, two 2245s would give you a sensitivity of 98 dB, and those other drivers don't look like they are anywhere near that sensitive. The system should sound mid and treble shy, unless you're using an electronic crossover. The upper drivers have to be at least as sensitive as the bottom drivers in a passive system.

[Lee in Montreal]

Ports look like 3" at most. I suggest they are for the 2118 drivers. I used two 6" ports per 2245. If the ports on the picture are indeed for the 2245, then I can say I use 4 times the area and could even go a tad bigger. Maybe the ports for the 2245s are at the back. Those cabinets don't seem very deep. And I wonder if the lack of bass could come from the following :

- Way too small volume behind the woofers
- I kinda understand the network is passive. May I suggest to make your life way easier and go active
- Run your 2118 down to 80Hz, then crossover to the 2245s
- Simplify. The 2118 easily reach 4KHz. Cross to the tweeter. Ditch a driver.
- Redesign those coffins. You don't need such subwoofers at top and bottom. Below 80Hz, bass is not that directional. Keep only one woof per side at the front. Then two per side behind you. Yup. One woof per corner.

@ Audiomagnate. The 2218 is 97db. Not too far from two 2245s. A single 2245 is 95db. Add 3db as a pair. And another 3db from coupling if installed together.

Have fun

Lee

[grumpy]

Nice to see your post! They remind me of large Duntechs in a way...
What did you base your system on? Or what design, that seems to not sound
as you expected? If four 2245s aren't enough, and sensitivity matching can be
ruled out, I'd suspect some destructive cancellation (driver phase, unfortunate
room geometry vs speaker placement, etc...)

looks like a lot lot of potential there :)

[audiomagnate]

[QUOTE=Lee in Montreal
@ Audiomagnate. The 2218 is 97db. Not too far from two 2245s. A single 2245 is 95db. Add 3db as a pair. And another 3db from coupling if installed together.

Have fun

Lee[/QUOTE]

I was talking about the dome mid and tweeter. I doubt that they are anywhere near 98 dB. They look like Morel/Dynaudio which are around 91-93 IIRC.

[Don C]

Too many speakers. There is one woofer receiving the benefit of boundary reinforcement from the floor, and a second that doubles the system sensitivity in its range, but without the benefit of any boundary reinforcement. The result is lots more mid bass, without adding much more low bass. My suggestion would be to use an equalizer and adjust it until you are happy. Oh, and as others mentioned, those shiny cones are not right.

[audiomagnate]

I can certainly understand how there isn't any real bottom; the box looks like it's about 12 ft3, 4 ft3 too small and the ports aren't the right size. The cabinets for the mid bass cones have to take up some room (assuming they have them!) so the internal volume would be reduced by that amount as well. But from 60 to 160Hz or so they must be cranking out around 98 dB. The most sensitive soft dome tweeter ever made was the 95 dB/19,000 gauss unit ADS made in the early 80's and used in the L1530/L2030 and later by Wilson, and that ain't it, so the tweeter level has to be at least 5 dB or more down from the mid bass output. Dome mids like that are usually around or even below 90 dB sensitivity, 8dB or more down from the mid bass output! I'm sorry, but they have to sound downright awful. A quick fix would be three more stereo amps, plus an active crossover and EQ to balance the driver output and force some bottom out of those undersized cabinets. It might help to redo the ports as well, or just plug them and EQ the hell out of the bottom end.

[ivica]

.... A single 2245 is 95db. Add 3db as a pair. And another 3db from coupling if installed together.

Have fun

Lee

Hi,
so, with 2 drivers per box, in 2pi space it would be abut 95+6= 101 dB, but as can be seen the drivers are in pi/2 surroundings, so another +12dB, reaching near SPL= 113dB/1W/1m, but in stereo application another +6dB for the frequencies , say , under 100Hz can be expected, so 119dB/1W/1m.
May be the drivers are connected in 'opposite phase' so, producing cancellation instead of 'coupling amplification'

regards
ivica

[gassman_67]

each 2118 is in a .5 cuft box, with 2 3 inch ports, on the rear...4 6" ports on the rear (each is 10.25" long). the total cabinet volume is 28.5 cuft, less the 2 mid enclosures.The atc mid is very efficient, and yes...the 8" and 18" vere verified at the driver and were wire properly (backwards...red to black...and verified with a 9v battery).. This was a Dunlavy type design, I had a pair of Dunlavy sc V...and liked them, but need more BASS..Trust me, these coffins actually are very musical and image great...just more boom would be what I'm after.. whch is why i was thinking running the 18" through an electronic xover and use a dedicated amp on them

[Earl K]

each 2118 is in a .5 cuft box, with 2 3 inch ports, on the rear...4 6" ports on the rear (each is 10.25" long). the total cabinet volume is 28.5 cuft, less the 2 mid enclosures.The atc mid is very efficient, and yes...the 8" and 18" vere verified at the driver and were wire properly (backwards...red to black...and verified with a 9v battery).. This was a Dunlavy type design, I had a pair of Dunlavy sc V...and liked them, but need more BASS..Trust me, these coffins actually are very musical and image great...just more boom would be what I'm after.. whch is why i was thinking running the 18" through an electronic xover and use a dedicated amp on them


( To help find the missing bass ) you'll want to confirm that the TS parameters of your 2245H's actually conform to JBL spec. ( to do this, you'll need to buy something like DATs from Solen.ca (https://solen.ca/products/electronics/test-equipment/dats/)) that can test a woofer parameters.

I'm guessing that you may of purchased these eighteens from Santon Audio . If so, dollars to donuts, you've got franken-woofers on your hands ( with unknown ts parameters ). Unknown TS parameters would make any box tuning predictions that you may have performed, null & void .

Those stated port sizes ( as well as, quantities & lengths ), suggest that you performed some box ( tuning ) predictions .



:)

[Lee in Montreal]

Could the woofers simply be out of phase?

Also, 1/2cft per 2118 might be too small.. When used in the 4612 Cabinet serie, volume was 2cft for 2 woofers

[gassman_67]

Thanks for the input folks.Chris from solen has fabricated the xovers and given me the .5 cubic suggestions and port calculations.the 18's are in phase...I did read up on how the terminals hook up backwards...and verified on the driver using a battery.I bought the 2245 from a friend who just had them serviced...and the dope was applied at that time

[BMWCCA]

As the owner of a pair of 4345s, I can't imagine anyone properly using FOUR 2245s properly ever complaining about lacking low-frequency output. The JBL specs for the 4345 show a 9-cu.ft. volume for the 2245 in the 4345. I suppose the questions left un-asked is what type of program material are you playing and what are the characteristics of the room? Also, what are your expectations? Musical representation? Home theater? I assume you've heard other systems that put out what you want. Have you heard such in your room?

Do you feel you're lacking "bottom end" as in subwoofer frequencies or just not enough bass kick, as in kick-drum force or punch?

What happens if you simply disconnect the upper 2245 in each enclosure? Ideally running the remaining 2245 off an active crossover and maybe crossing it a bit higher. The 4345 uses 290 Hz which is what I use in my bi-amped system.

:dont-know:

[Lee in Montreal]

Okay then. The amount of bass you get is also dictated by the amount of upper bass, mid, highs etc. Since you run a passive network, then you might want to pad all drivers except the 2245s. And honestly, it is when you realize that running an active crossover makes sense. It ends up being way more flexible. And cheaper ;-)

Lee

[Lee in Montreal]

BMWCCA might be on something here whe he asks what type of bass is missing.

The 2245 will not get you kicking bass but is great for that bottom octave and 80Hz bass. Kick at 120Hz? Not so. Then the 2118 are great for vocals, not for bass. Especially in small 1/2cft enclosure.

For bass, I run a pair of 2226 (great for kicks, and down to 40Hz), and a single 2245 for 40Hz and down. Driven by a digital crossover and two amps. This gives way more bass than anybody can wish for.

My suggestion? Ditch the 2118 and replace it by a 2226. Crossover at 50Hz. Run active. Basically go back to square one. Maybe you can reuse you "coffin" if the middle panel unbolts.

[audiomagnate]

Hi gassman,

There has to be plenty of deep bass. I like Lee's idea about the 2216 if you can fit one in there. What is make and model of you mid dome and tweeter. If they aren't at least 98 dB sensitivity, you simply have to go with an electronic crossover.

[rusty jefferson]

Hello all, my first post here.I have built a tower speaker with twin 2245, twin 2118, an ATC domed mid and Scanspeak 9900 tweeter, my issue is lack of bottom end,they are on a passive crossover and at 160hz. For power on this setup, a Krell 750 mono, each cabinet is 80x22x30, with 4 6" precision ports (10.25" each). I'd lke to get a bit more out the 18's
thanks!

That's a pretty impressive DIY build you have there! Hope you can get the bugs worked out. As others have already pointed out, missed wiring can be the cause of cancelled bass. Are all your woofers moving out (compression) with the battery check at the binding post, through the crossover?

I noticed your thread at DIYAUDIO (http://www.diyaudio.com/forums/parts/271814-speaker-wire-suggestions.html) from back in May. You mentioned there the nominal impedance will be 4ohms. Are you using the same crossover? I don't know if the 2245h runs properly at 4ohms. Do you have a schematic of the crossover? Some members here are quite knowledgeable of passive crossovers (not me) and may be able to offer help if it's the problem. I include the photo you posted at DIYAUDIO.


67289

[gassman_67]

The mid dome is a atc sm75-150 and the tweeter is a scanspeak 2905/9900..I've had wilson maxx 1..dunlavy sc V.... I use this setup as theater and 2 channel.mainly classic/prog rock.
I use a velodyne dd18 also...which actually blends in quite nice.I guess I had anticipated real slam from the 2245's.but as mentioned..they are quite musical.as discussed earlier...probably going all active will be the way to go

[gassman_67]

Yup...those are my crossovers...160hz at [email protected] (I think...or close to)
This cabinet is about 450 pounds..if not more

Chris at Solen built the xovers...

[Lee in Montreal]

...probably going all active will be the way to go

That will allow you to tune the sound to your preferences.

[gassman_67]

Lee, one pair of 2118 have nice nickel push down binding posts..the other pair have the crappy plastic push type.can these be removed and modified?if so....who does this mod or is it simple to do?

Thanks

[Lee in Montreal]

Lee, one pair of 2118 have nice nickel push down binding posts..the other pair have the crappy plastic push type.can these be removed and modified?if so....who does this mod or is it simple to do?

Thanks

Binding posts cannot be swapped as the frames are different if I am not mistaken. But don't spend too much energy on those 2118 as you will soon change them for some 2226 ;-)

Lee

[ivica]

Yup...those are my crossovers...160hz at [email protected] (I think...or close to)
This cabinet is about 450 pounds..if not more

Chris at Solen built the xovers...

Hi gassman..,

Looking at the network figure, I seems to that the networks are of 12dB/oct slope type, so the phase of the drivers has to be inverted between each pairs.
My be you can show us the schematics.
regards
ivica

[gassman_67]

Binding posts cannot be swapped as the frames are different if I am not mistaken. But don't spend too much energy on those 2118 as you will soon change them for some 2226 ;-)

Lee
if i had the real estate ...I'd use the 15" as mid/bass!

[audiomagnate]

The mid dome is a atc sm75-150 and the tweeter is a scanspeak 2905/9900..I've had wilson maxx 1..dunlavy sc V.... I use this setup as theater and 2 channel.mainly classic/prog rock.
I use a velodyne dd18 also...which actually blends in quite nice.I guess I had anticipated real slam from the 2245's.but as mentioned..they are quite musical.as discussed earlier...probably going all active will be the way to go

Both of those drivers have a sensitivity of 91 dB. Your woofers are rated at 95 dB, and you have two them, so each speaker is 98 dB sensitive in the bass. Let's forget about slam, deep bass etc. Unless you are drastically padding down the output of the woofers, which is just weird and hardly ever done, you have a HUGE mismatch there. The level from your tweeter and upper mid is at least 7 dB lower than the level of your woofers. They have to sound dull as dirt. You can use upper drivers that are MORE sensitive than your woofers and pad the upper drivers down or use multiple woofers, but it is HIGHLY unusual to use upper drivers that are less sensitive than your woofer(s) with a passive crossover.

If that bank of resistors is padding down your woofers and your eight inchers then I guess it could work in theory, but it's an incredibly, umm, unusual design, that is wasting the vast majority of your expensive amp's power. The resistors don't seem large enough to do the job anyway, so what ARE they doing anyway? Does anyone else see my point here?

As the to Velodyne, that makes no sense either, but who cares? You have to have spent a fortune on an absolutely awful sounding system.

I use a low sensitivity supertweeter (8k and up) with my L200's, but i use an electronic crossover and a separate amp to bring the level up to the rest of the system.

[Lee in Montreal]

if i had the real estate ...I'd use the 15" as mid/bass!

You would be happily surprised at how good a 2245 / 2226 combo sounds.

If I were you, I would build, just for testing, a single 10cft cab for a 2245 and a two 5cft cabs for the 2226s. It will be cheap, and you can experiment with this combo. Use the 2245 up to 50/60Hz, then the 2226 up to 600/700Hz. That is a killer combo for bass at home. You get low bass and punchy kick. I wouldb't even bother with the 2118 as I think that they are great for vocal reinforcement but certainly not for bass.

Few more questions. Your two 2245s are 8 Ohms. Correct? And they are connected in parallel, giving 4 Ohm at the dividing network.

Lee

PS, to make things simpler for you, maybe you can keep all your drivers as is. Put aside the analog crossovers, and replace them with an active digital unit. Experiment with levels, phase and tonal correction. The you'll know what the system is capable of. At that point, you can decide if you keep and modify the analog filters, or keep the digital one. 3-way digital crossovers are cheap. 4-way systems are more expensive. So maybe you get a 3-way from Behringer to feed the 2245, 2118, and higher range as a combo including the analog crossover.

http://www.axemusic.com/live-sound/signal-processing/pa-system-controllers/behringer-dcx2496-ultra-drive-pro-system-controller.html

[audiomagnate]

...Put aside the analog crossovers, and replace them with an active digital unit. Experiment with levels, phase and tonal correction. The you'll know what the system is capable of. At that point, you can decide if you keep and modify the analog filters, or keep the digital one. 3-way digital crossovers are cheap. 4-way systems are more expensive. So maybe you get a 3-way from Behringer to feed the 2245, 2118, and higher range as a combo including the analog crossover.

http://www.axemusic.com/live-sound/signal-processing/pa-system-controllers/behringer-dcx2496-ultra-drive-pro-system-controller.html

If by analog filter you mean passive, you can't make a passive crossover work properly when your woofers are 7 dB more sensitive (98 dB) than your upper mid and tweeter (91 dB). I officially give up,as nobody seems able to grasp the most basic point about putting together a speaker system, i.e. your tweeter has to be at least as sensitive as your woofer if you have a passive crossover. You can pad down a tweeter, but padding a woofer down is impractical and down right stupid. Good grief guys. Anyway, I'm sure this system could be made to sound excellent with a four way electronic crossover and three more stereo amps, as the drivers are all very high quality and the boxes and layout seem fine. End of rant.

[gassman_67]

If by analog filter you mean passive, you can't make a passive crossover work properly when your woofers are 7 dB more sensitive (98 dB) than your upper mid and tweeter (91 dB). I officially give up,as nobody seems able to grasp the most basic point about putting together a speaker system, i.e. your tweeter has to be at least as sensitive as your woofer if you have a passive crossover. You can pad down a tweeter, but padding a woofer down is impractical and down right stupid. Good grief guys. Anyway, I'm sure this system could be made to sound excellent with a four way electronic crossover and three more stereo amps, as the drivers are all very high quality and the boxes and layout seem fine. End of rant.

thanks for the rant...

[gassman_67]

You would be happily surprised at how good a 2245 / 2226 combo sounds.

If I were you, I would build, just for testing, a single 10cft cab for a 2245 and a two 5cft cabs for the 2226s. It will be cheap, and you can experiment with this combo. Use the 2245 up to 50/60Hz, then the 2226 up to 600/700Hz. That is a killer combo for bass at home. You get low bass and punchy kick. I wouldb't even bother with the 2118 as I think that they are great for vocal reinforcement but certainly not for bass.

Few more questions. Your two 2245s are 8 Ohms. Correct? And they are connected in parallel, giving 4 Ohm at the dividing network.

Lee

PS, to make things simpler for you, maybe you can keep all your drivers as is. Put aside the analog crossovers, and replace them with an active digital unit. Experiment with levels, phase and tonal correction. The you'll know what the system is capable of. At that point, you can decide if you keep and modify the analog filters, or keep the digital one. 3-way digital crossovers are cheap. 4-way systems are more expensive. So maybe you get a 3-way from Behringer to feed the 2245, 2118, and higher range as a combo including the analog crossover.

http://www.axemusic.com/live-sound/signal-processing/pa-system-controllers/behringer-dcx2496-ultra-drive-pro-system-controller.html

yes, the 2245's are 8ohms

[1audiohack]

If by analog filter you mean passive, you can't make a passive crossover work properly when your woofers are 7 dB more sensitive (98 dB) than your upper mid and tweeter (91 dB). I officially give up,as nobody seems able to grasp the most basic point about putting together a speaker system, i.e. your tweeter has to be at least as sensitive as your woofer if you have a passive crossover....


2245's are not 95dB SPL @ 1Watt @ 1Meter on or off axis down low (20-160 Hz) and these are not running to 800-1kHz where that efficiency rating comes from.

If they are six feet apart, vertically, the mutual coupling falls apart in the high 40's. They have a pretty narrow baffle, and and and,,.

I think it was Don Davis who said, or quoted in one of his books, "When the number of variables reaches an order of magnitude, in dispair, I turn to my measurement apparatus." I think that is good council in this case.

Barry.