For background purposes, I have a Blueprint Designs 1503 in a 5.3 cubic foot vented enclosure tuned to 20Hz and an Adire DPL12 in a 2.4 cubic foot sealed enclosure. I am not happy with either, though when both are run together, the result is more ok...
My complaints? Well, for home theater, the BPD is great as far as the slam factor goes. It is not so good for music, though... too slow responding. BUT, when I am playing movies, it rattles the floorboards in my room under it. I live in a ~100 year old house and understand this can happen, but it bugs me a lot. I think it probably occurs because it is a down firing design. In addition to this, it seems as though there is some sort of air leak around the driver that is causing a fffffff sound when the sub plays low and loud (ie LOTR scenes and the like). I absolutely hate this sound- even more than the floorboards rattling. So, I guess my first question: If I place something under the sub, will it help to kill the rattling floorboards? If so, what might I try? It would need to be about 20"x20" and a circle would work fine (it's a sonosub). Granite? Marble? Also, I guess I need to seal the sub to the bottom (even though I've really been wishing I could build a box to move it to a front firing design... but I fear I'll never succeed because I am a bad carpenter). What should I use to provide a non-permanent, but good seal between the driver and the bottom piece of plywood?
Now on to the DPL12... it has no output. Weak. You could run it full steam from my 1100W amp (which would no doubt kill it) and probably still couldn't hear it over my mains (>98dB 1W/m efficient). Anyway, running it with my non-musical sounding BPD1503 seems to even out the bass for music, making it sound not so sluggish. I don't have a whole lot of complaints about it, I suppose... except that the 2.4 cubic foot enclosure takes up more room than I would like it to. For being so large, it sure doesn't offer much in the performance category.
Anyway... What might I do to help out my rattling's and air leaks? I am really beginning to dislike all my home theater equipment, but the subs really eat me up. I literally cannot enjoy a movie anymore because the rattling just annoys me so much. Any suggestions are MUCH appreciated.
My complaints? Well, for home theater, the BPD is great as far as the slam factor goes. It is not so good for music, though... too slow responding. BUT, when I am playing movies, it rattles the floorboards in my room under it. I live in a ~100 year old house and understand this can happen, but it bugs me a lot. I think it probably occurs because it is a down firing design. In addition to this, it seems as though there is some sort of air leak around the driver that is causing a fffffff sound when the sub plays low and loud (ie LOTR scenes and the like). I absolutely hate this sound- even more than the floorboards rattling. So, I guess my first question: If I place something under the sub, will it help to kill the rattling floorboards? If so, what might I try? It would need to be about 20"x20" and a circle would work fine (it's a sonosub). Granite? Marble? Also, I guess I need to seal the sub to the bottom (even though I've really been wishing I could build a box to move it to a front firing design... but I fear I'll never succeed because I am a bad carpenter). What should I use to provide a non-permanent, but good seal between the driver and the bottom piece of plywood?
Now on to the DPL12... it has no output. Weak. You could run it full steam from my 1100W amp (which would no doubt kill it) and probably still couldn't hear it over my mains (>98dB 1W/m efficient). Anyway, running it with my non-musical sounding BPD1503 seems to even out the bass for music, making it sound not so sluggish. I don't have a whole lot of complaints about it, I suppose... except that the 2.4 cubic foot enclosure takes up more room than I would like it to. For being so large, it sure doesn't offer much in the performance category.
Anyway... What might I do to help out my rattling's and air leaks? I am really beginning to dislike all my home theater equipment, but the subs really eat me up. I literally cannot enjoy a movie anymore because the rattling just annoys me so much. Any suggestions are MUCH appreciated.
Oh boy.
Well, your blueprint subwoofer is probably OK but the diameter of the port is probably not big enough.
You could test it out by playing a 20 Hz sinewave at high power to see if you hear the port noise. If it's that, you would need a bigger diameter port, another same diameter port or a passive radiator. I hope your current port is flared on both ends.
Going to frontfiring won't be better. You'll lose some output. It will shake on the floor a bit more and still shake floorboards. A downfiring design is more stable. Probably a marble or granite slab would help, but then glue or foam or rubber between floorboards would help too.
Then, your DPL12... the box is too small if you want to have some low end. It would sound great in your 5.3 cu. ft enclosure.
Well, your blueprint subwoofer is probably OK but the diameter of the port is probably not big enough.
You could test it out by playing a 20 Hz sinewave at high power to see if you hear the port noise. If it's that, you would need a bigger diameter port, another same diameter port or a passive radiator. I hope your current port is flared on both ends.
Going to frontfiring won't be better. You'll lose some output. It will shake on the floor a bit more and still shake floorboards. A downfiring design is more stable. Probably a marble or granite slab would help, but then glue or foam or rubber between floorboards would help too.
Then, your DPL12... the box is too small if you want to have some low end. It would sound great in your 5.3 cu. ft enclosure.
simon5 said:
I acually laughed out loud at this last. I was thinking, 2.4 feet is too big but 5.3 is not, and then this! 😀
Anyhow, with a house that old, you might begin to be concerned about the whole shebang falling through if you put enough weight under an already-heavy sub to quiet the floorboards! Better, try adding screws where required to secure the floor.
It doesn't take a master craftsman to make a side-firing enclosure... just go slow and be sure you cut only what you wanted.
As far as the gasket for the driver itself, you can buy any of several purpose-built materials for it but you may have some normal weatherstripping laying around that would do the trick. If it's leaking around the screws, you need a bit more work but still repairable.
Sorry if it sounded funny, but a DPL12 models almost like a Shiva, and a Shiva is great in a large box of 5 cu. ft or so.
A leak around the driver in a vented system? That seems unlikely unless the vent is blocked. There should be almost no resistance to airflow in a vented design and air wouldn't naturally flow out the speaker gasket. Air leaks around the driver would more likely be a problem with the sealed sub. If you have a leak around the sub you should be able to feel it if you wet your fingers - any air will feel cold. Other problems to check for - overstuffed cabinet in the vented system.....too small a vent diameter....error in the design....
hofffam said:
There is resistance to airflow in the port unless you're below tuning. I believe leaks were even worse in ported boxes than in sealed.
I always re-read my posts and always realize I never quite said what I wanted to say... so I reply and still don't quite get out what I need to convey... Anyway...
The DPL12 box being too "big" was a preformance thing to me. I did some figuring and came to the conclusion that I could put it in a box as small as 1 cubic foot and still get the almost same SPL levels from it from 20Hz up. So, it really defeats the purpose to have it in a much larger enclosure when I am not gaining any performance from it. As a note, I've tried it in the larger enclosure (it was actually originally for the DPL12) and was not any more happy with the results. I got no more low end and still it didn't have enough output to match my mains. I don't listen very loudly either... it just doesn't keep up on its own for some reason.
The 1503 definitely has a leak around the driver. I am hoping it is not coming from the screws. Actually, I am not sure how it could be coming from the screws... or leaking at all for that matter. I have a 2" plug inside of the tube with the outside piece attached via a couple of screws, but everything it caulked through and through. The speaker fits snugly into the hole and has that rubber mounting thing that I thought was supposed to act as a gasket of sorts. The only thing I can think is that the driver is so heavy that it is sagging just a small amount in between the screws to allow air to flow. I can feel cold air around it and it makes that darned annoying noise (and loudly enough to be heard at listening position 4 feet away). I guess I'll try experimenting with what I can do...
The DPL12 box being too "big" was a preformance thing to me. I did some figuring and came to the conclusion that I could put it in a box as small as 1 cubic foot and still get the almost same SPL levels from it from 20Hz up. So, it really defeats the purpose to have it in a much larger enclosure when I am not gaining any performance from it. As a note, I've tried it in the larger enclosure (it was actually originally for the DPL12) and was not any more happy with the results. I got no more low end and still it didn't have enough output to match my mains. I don't listen very loudly either... it just doesn't keep up on its own for some reason.
The 1503 definitely has a leak around the driver. I am hoping it is not coming from the screws. Actually, I am not sure how it could be coming from the screws... or leaking at all for that matter. I have a 2" plug inside of the tube with the outside piece attached via a couple of screws, but everything it caulked through and through. The speaker fits snugly into the hole and has that rubber mounting thing that I thought was supposed to act as a gasket of sorts. The only thing I can think is that the driver is so heavy that it is sagging just a small amount in between the screws to allow air to flow. I can feel cold air around it and it makes that darned annoying noise (and loudly enough to be heard at listening position 4 feet away). I guess I'll try experimenting with what I can do...
You don't mention whether or not you've calibrated the system either. Maybe you just need to turn up the DPL12 in relation to your mains? Might want to play with placement also; you may have some dips in your frequency response that make the bass sound weak.
Leaks around the driver frame or the screws shouldn't be hard to fix. Is the surface under the driver frame flat? Does the foam gasket have a gap?
I suggest you pull the driver and replace the foam gasket with rope putty. Don't flatten it much as you apply it. Run the putty in the middle of the speaker flange, but run it to the inside edge of the screw holes. Put a small additional piece around each of the screw holes on the outside. You can't have leaks through the screws if your screws go straight into wood. If you use T-nuts, air could leak through the screws, through the holes in the speaker frame. To fix that, seal the back side of the t-nuts in the cabinet if the screws don't go that far. If the screws go that far, as they do in my sub, I use small o-rings under the screw head.
I suggest you pull the driver and replace the foam gasket with rope putty. Don't flatten it much as you apply it. Run the putty in the middle of the speaker flange, but run it to the inside edge of the screw holes. Put a small additional piece around each of the screw holes on the outside. You can't have leaks through the screws if your screws go straight into wood. If you use T-nuts, air could leak through the screws, through the holes in the speaker frame. To fix that, seal the back side of the t-nuts in the cabinet if the screws don't go that far. If the screws go that far, as they do in my sub, I use small o-rings under the screw head.
i have the dpl in a shiva 142.5L ebs box tuned between 16 and 17hz with 240 watt PE amp. it also is weak compared to my mains but, i fed the sub amp from a set of the outputs on my adcom gfp 565 preamp where i could use tone controls to boost the bass a little at 20hz only on the sub which helped alot. i also, reduced the input sensitivity on my main 2chL power amp which is also fed from the preamp bypass outputs. i've now ordered a pair of lpads to put on my tweeters which seem to have the most output on the mains and i think, i'll have everything balanced out pretty well. as far as the sound of the dpl, i think it sounds great with verry accurate, tight, sounding bass used mostly for music with my setup. of course, i just have a small room i'm using it in which could be a main factor also. good luck, crippledchicken 🙂
How are you crossing over to your mains? How are you calibrating the system? Do you have a radio shack spl meter or other measurement system, and have you used it to see what your in-room bass response looks like?
Sorry for the delay in response... I got sidetracked...
For all intents and purposes, let's disregard the DPL12. It is a good sub, but will not keep up with my mains no matter what.
The BPD, though, can keep up, but just sounds much slower responding for music. Poor enclosure design/construction can cause sluggish bass response, yes? If so, that is probably the cause. I am a horrible carpenter. The enclosure is also probably tued wrong, since I could not get a correct figure for Le of the driver and port length could be off as much as 2".
That being said, it also can rock from side to side a little... so it probably loses some energy by motion of rocking, and the enclosure is not damped per se. I didn't fill it with any foam...
Would that lend sluggish response for rapidly succeeding bass notes?
I am in the process of trying to decide what to do from here. Since I have no faith in myself as a carpenter, I am thinking about ordering an enclosure that'll provide enough volume, two 4" flared ports, and some speaker spikes. With all that, maybe it'll clean up the response and help it to sound better, cleaner, and punchier.
On the other hand, I may just scrap the DIY route and sell my drivers in favor of a ready-made sub. I am looking especially towards SVS CS-Ultra and the Axiom Epicenter.
I do have an SPL meter, and have investigated the bass response in room... and it is very jagged. I don't remember how it was exactly, but it was fairly rough, I think. I don't have the best room for bass, but I cannot put any bass traps in here, mostly for lack of room.
Between rebuilding my BPD sub for ~$350 and selling off and buying an SVS CS-Ultra for ~$900, which would probably be the most rewarding? I cannot hardly fathom that the SVS could best the 115dB at 20Hz anechoic of the BPD... but its the sound quality that really matters...
For all intents and purposes, let's disregard the DPL12. It is a good sub, but will not keep up with my mains no matter what.
The BPD, though, can keep up, but just sounds much slower responding for music. Poor enclosure design/construction can cause sluggish bass response, yes? If so, that is probably the cause. I am a horrible carpenter. The enclosure is also probably tued wrong, since I could not get a correct figure for Le of the driver and port length could be off as much as 2".
That being said, it also can rock from side to side a little... so it probably loses some energy by motion of rocking, and the enclosure is not damped per se. I didn't fill it with any foam...
Would that lend sluggish response for rapidly succeeding bass notes?
I am in the process of trying to decide what to do from here. Since I have no faith in myself as a carpenter, I am thinking about ordering an enclosure that'll provide enough volume, two 4" flared ports, and some speaker spikes. With all that, maybe it'll clean up the response and help it to sound better, cleaner, and punchier.
On the other hand, I may just scrap the DIY route and sell my drivers in favor of a ready-made sub. I am looking especially towards SVS CS-Ultra and the Axiom Epicenter.
I do have an SPL meter, and have investigated the bass response in room... and it is very jagged. I don't remember how it was exactly, but it was fairly rough, I think. I don't have the best room for bass, but I cannot put any bass traps in here, mostly for lack of room.
Between rebuilding my BPD sub for ~$350 and selling off and buying an SVS CS-Ultra for ~$900, which would probably be the most rewarding? I cannot hardly fathom that the SVS could best the 115dB at 20Hz anechoic of the BPD... but its the sound quality that really matters...
The BPD driver is a very good subwoofer driver. You could do something amazing if the box is well built. The "problem" is because your mains are so efficient. 😀
I would build another box. Do you have friends good at carpentry? Or your father maybe?
Foam inside doesn't give better sound, it just makes the volume virtually larger for the driver... but you lose SPL, something not acceptable for mains as efficient as yours IMHO.
I would build another box. Do you have friends good at carpentry? Or your father maybe?
Foam inside doesn't give better sound, it just makes the volume virtually larger for the driver... but you lose SPL, something not acceptable for mains as efficient as yours IMHO.
I'd also spend another $100 or so and invest in a Behringer Feedback Destroyer to eq the sub. Should make it sound quite a bit better if you've got a jagged room response.
I have put the BFD on my list of things to buy next...
I can't think of anyone off the top of my head that is a good carpenter or has the spare time to build a large box... I may have to re-do my sonotube once again. Make it a little larger, a little more well put together... and actually damp it this time. The thing rings like crazy if you tap the side. I really do want it forward firing, though... do I lose any slam having it forward firing? I've read that it'll increase the slam and that it will decrease the slam.
I can't think of anyone off the top of my head that is a good carpenter or has the spare time to build a large box... I may have to re-do my sonotube once again. Make it a little larger, a little more well put together... and actually damp it this time. The thing rings like crazy if you tap the side. I really do want it forward firing, though... do I lose any slam having it forward firing? I've read that it'll increase the slam and that it will decrease the slam.
needtubes said:
The fact that your main speakers are more efficient may not be relevant to your situation. So far you have failed to provide any details about your setup. How are you crossing over to your sub?
A forward firing sub in a sonotube is going to lose much. It will be so light that you will find it scooting across the floor.
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