I'm new to the forum, and have a single 15" IB...

[Wes Whitmore]

Hello Everyone!
I'm new to the forum, and haven't been on many home audio forums.
I have had a single Dayton IB15 and a Dayton 150 watt plate amp for a while now. It is in my partially finished basement that is 31x16 or so (I have a half wall that the couch rests up against, making the HT area roughly 15x16). I have it mounted in the wall to the right side of the listening position under the stairs. It was the only place to put it, but it sounds great. The output qualities are nearly perfect, except for I think I am getting into a little bit of overexcursion during some DVD playback at high volumes. I heard it during the intro of Gladiator during the woods fighting scene. Now I know that I went with a low power speaker with moderate XMAX. The price was right, and I am about an hour from Parts Express. Now, I want to add to the system just enough to get rid of the slight overexcursion so I don't hear the distortion. Do you think adding one more of the Dayton's will do the job? My SPL is fine, I just don't like the distortion. Since I only have one driver, I can yank it out and get 1 or 2 Soundsplitters too, which seem to take more power and have much better XMAX. It doesn't seem that people are really using the Daytons anymore. Any reason why?
I'm really just looking for some general guidance. I don't have a BFD, although I do have a DBX driverack to use if I have to. I don't have any RTA gear, and the system is running without any EQ. My ears don't know better, and I very happy with the SQ of the whole system.
Thanks,
Wes

[Otto]

Hi Wes,

Adding another drive will "only" get you a 3dB increase in usable output. It may be the case that it would be enough for your needs, if you are only bottoming your driver every once in a while.

On the other hand, it sounds like you are really using the out of that driver -- it probably moves quite a bit when things get going, right? Hence the bottoming. All in all, I'd probably move on to something with a little more headroom...

As to why people aren't using the Daytons anymore, I'm not sure. SoundSplinter has a great reputation around here and on other forums. If you don't have a problem with the cost, I'd probably recommend going that way -- getting two of them to replace the one Dayton. With their increased Xmax (and, I think, increased power handling), you should really notice a difference. With two of those guys, you might consider a different amp as well -- the Behringer stuff is pretty popular and cost effective. I think other people also use Carvin, Crown and QSC -- all pro amps with lots of power.

Once you get it all set up, you may want to do some sweeps to see your frequency response. It's a fun, entertaining and enlightening exercise. After that, and if you decide you need it, the BFD is also lots of fun and made a big difference for me.

Have a good day.

[Eddie Horton]

No matter what you do about changing or adding drivers, I would strongly suggest either using RoomEQ Wizard or taking manual plots of your frequency response and using a BFD to tweak it. The BFD made the largest noticable improvement I've ever had in my HT. The difference in movie watching by itself was big, but the difference in music listening was incredible. There's nothing like having all the bass notes just jump out at you individually.

[Wes Whitmore]

Well, my costs wouldn't be nearly as bad since I have a Crown CE1000 amp lying around. My LFE output was too low to run that amp, so I would have to get a line driver as well.

For $99, I could get the BFD. I have a DBX driverack that I could use as well, but it sounds like it would be a little overkill.

I am working the speaker pretty hard on some of those bassy moments.

It's the old story of buy one more speaker and see what happens, or cut my losses and start again with a better platform.

Thanks for the insight. I should probably just start with another higher XMAX driver and go from there. I will just sell my friend my Dayton in the basement we just finished.

Thanks again,
Wes

[Darren]

If you stick with the Dayton driver I'd go no less than 4 of them. If you upgrade to SoundSplinter you might try 2 first and see what that gets you, it should be more displacement than 4 of the Daytons but I haven't calculated that so you'll need to verify. I have 4 of the SoundSplinters driven by a Behringer EP2500 and I can bring the house down if necessary and the drivers are barely getting worked out.

[Wes Whitmore]

4 is something that I don't know if I need. Since the new baby addition 4 months ago, I'm lucky to give my single 15 a workout. Still, it's very impressive.

So, I am going to create a new manifold for future expansion. it looks like it is a bad idea to run speakers in the non vertical arangement on a cubed manifold. Since mine are going on a verical wall, I would probably have to run 2 on the left baffle and 2 on the right baffle, firing into a single 16" shared space. That would still be OK, right? The good thing about that is that it's should be very modular. I can start with 2 and add 2 more later, Not that I need it. Luckily, all that space under the stairs is reserved for the HVAC, water heater, and an air-compressor and vacuum system for my woodshop. There's tons of airspace back there if the woofers need it.

My mains probably woudn't keep up with more than 2. I have 4 way AR towers with 8" powered subs, an AR center, and AR inwalls for surrounds. I new receiver greater than 90 watts per channel might be in order as well.

You guys make people spend money!

It's fun though.

Wes

[Darren]

You could definitely do two on one side and two on the other, perfectly adequate. I'd start with one on each side but cut the holes for the other two and put covers over them. Two of the SS drivers will basically be like adding 4 or more daytons. I think you'd be very pleased and would have room for future expandability. Your Towers should keep up just fine if you calibrate your system correctly. My guess is you have your bass too hot trying to compensate for the lack of output from one single moderate excursion driver which is why it's bottoming sometimes. Going with two SS RL-P15's will open your eyes dramatically!

I started with 2 experimental moderate excursion drivers and was impressed, not bad I thought. I added two more and got better low end extension. Wow! I was happy but wanted more SPL so I returned the experimental drivers I was testing and ordered 4 RL-P 15" drivers. HUGE improvement but of course you pay for it. The other drivers met my expectations but I wanted more than they could provide.

If I were you and could afford to go with two SS RL-P15's I'd go that route and leave room for two more for the future although I'm sure you'll be happy with two.

My system may be considered overkill by some in my room. I can easily hit 120db with just the subwoofer and no mains. I love knowing I can do that but what is more important is that I get wonderful bass at normal listening levels without strain... my amp sometimes strains at higher volumes but thats a different issue as the drivers haven't even broken in fully yet.

[Wes Whitmore]

Well, I got a chance to listen to it again yesterday. I'm already wanting more. It might be because I had my neighbor over to listen to it. I turned to gain down enough that the speaker wouldn't have a chance of bottoming, and of course, all of my volume went away too. It was better than most sub woofers that I have heard, but it's time to work on an upgrade. Now if I can just sneak out $500 from the bank without my wife noticing.

Wes

[Chrisbee]

I'm using 4 similar 15" in a similar sized room and rarely get any serious excursion. I'm amazed your single driver has survived!

It is nice to be able to relax and use any bass level you like when watching a new film without worrying about cone excursion.

I worried for ages that something in my 4 x15" would break and then I wouldn't be able to replace my discontinued drivers. (Freight charges to Europe for 4 new 15-18" drivers is more than the cost of the drivers!)

Now I just use any level I feel like. (usually loud! ) We often enjoy 6 new hired films almost every weekend and just sit and grin at each other on the bassy moments.

I'd think in terms of 4 x 15" PE drivers. Or at last two drivers with serious Xmax and an option on two more. The better the bass gets the more you want without even realising it.

The more drivers you use the better the bass sound quality, the lower the distortion, the higher the headroom and the stronger the dynamic peaks. Each new driver is an insurance policy against disappointment.

BTW. A low wall dividing the room is invisible to a sub. It sees the whole room and tries to drive the whole room whether it likes it or not.

[Wes Whitmore]

Chrisbee,
At $120 each, plus next day shipping from the nearby seller, I think I will just get more PEs. It's a little more modular (less cash on each step). I don't like using 4 subs when 2 higher xmax ones will do, but I guess there is always something better.

Also, I have 2 powered 8" subs in my towers that are helping out a little bit. I am sending 60Hz on down to the IB.

Just doing some setup will bring out my weakest link in the system, then I will know what direction to go with the upgrades. i think it's safe to say that I need at least 1 more driver though.

It's nice to hear that even your "average" 15s are very impressive. It gives me something to shoot for without blowing the budget.

Wes

[Darren]

It's nice to hear that even your "average" 15s are very impressive. It gives me something to shoot for without blowing the budget.

Yup, I'm sure you'll love 4 of those 15's... quite an improvement over one

[Wes Whitmore]

So I was thinking on my way home. Can I build a vertical stack with two opposing (or even 3 on every side by the wall), but extend the manifold to the floor, and have my 15x15 opening into the room. It shouldn't be much different than running then horizontal like we talked about before. It would make better use of the storage area so I'm not tripping on the speakers stepping over them. It would also allow it to couple to the wall better because I could wedge the manifold between the studs. The baffles would be some 20" wide to fit the whole width of the stud they are attaching too, but be wide enough to hold the woofer. I could go as tall as I wanted, and could even make it modular and attach enough manifold to build two at a time, or whatever.

Wes

[Wes Whitmore]

So here is a very crude drawing of what I was thinking. I could build 1 manifold, cover it with plates, and just add drivers as I see fit. If I am always going to want more, I might as well plan for it.

Any reason why this wont work? I was just going to start at the bottom left and right and work my way up. The ohm load will have to be worked out as I add drivers.


Thanks again,

Wes

[Darren]

With that design you won't benefit from any mechanical cancellation of vibrations, I think you would have timing issues as well. Also, it is generally a bad idea to go with odd number of drivers. Hard to get a correct load on the amp. If you go with 4 then I'd go with 2 on opposite sides or all 4 in an array. I'd stick with 2, 4, or 8 type of arrangement.

[Wes Whitmore]

Not a problem on the number of arrays. I think my drawing was confusing anyhow. There are really 9 spots for woofers, but there is really no need for that. As far as I will ever get is 4, so they will be on the left and right, facing into the manifold. There's mechanical cancellation that way.

My basement is full of birch plywood accents. I have a 10' ledge on top of my halfwall, a cap for my stairs, and I have some guitars hanging on plywood sheets. It's kinda a Chipotle look. I might just get rid of the metal cold air return grill and frame in the opening of the manifold on the HT side, and put a cool red or blue light in there to show off those woofers!

I'll see how 2 or 4 gets me first.

Thanks for all of the support.

Wes

[Wes Whitmore]

I gathered up a couple of pictures of the basement to give you an idea of what we are working with. I didn't have any ready for the space on the other side of the wall where the manifold will live. It gives you a good idea what's going on though.

Next step is a build-in on the TV wall and getting rid of that stand.

http://new.photos.yahoo.com/weswhitm...60762341946275


Wes

[adogand6kids]

Wes,

I looked at your pictures and I would suggest that if you go with the four 15" drivers in a rectangular manifold that you consider making your manifold opening into your theater room a bit larger. A guide I have heard quoted is to try to have the area of your manifold opening be equal to the combined area of your IB drivers. I stole the following quote from the "cult of the infinitely baffled" web page.

How big should I make my manifold/outlet?

"This is a situation where bigger is always better. If you don't want to make structural changes, then you must work within the existing framing. This means adapting the design of the manifold. For example, let's start off with standard 16" OC joist spacing. This limits the opening to 14.5" in one direction. One can make a 16" cube and mount 4-15"s in it. This is absolutely the smallest opening possible without detrimental bandpass effects occurring. If possible, a better choice is a rectangular manifold, that's external dimensions are 17.5" X 32", with a corresponding 14.5" X 30" opening".

Also, if you can get away with it, try moving your main speakers off the front wall and out into your room a foot or so. Try to get the face of your drivers in front of your TV and stand.

[Wes Whitmore]

I will pull them forward and see if it works better. They are pretty far back there. Should I face them towards the center a little, or leave them 90 degrees from the wall?

I did measure my stud openings yesterday. I have 17.5 " of spacing from inside to stud to inside of stud for my baffle, instead of the usual 14.5. I built that wall at the same time I built my IB baffle, so it's a little custom in width. I have at most 50" in height for an opening, but I can guarentee that my wife won't like a 16 x 45"ish hole in that wall...

I know that is a perfect scenario (and it makes sense), but it looks like a bunch of people here have 4+ drivers coming out of a 16x16 hole. I have even seem some of those 8+ driver systems coming through a pretty small hole.

I guess I will just have to go as big as I think I can get away with!

Thanks for the input. I'll let you know if the mains sound better.

Thanks,
Wes

[JCD]

Wes Whitmore wrote:

I will pull them forward and see if it works better. They are pretty far back there. Should I face them towards the center a little, or leave them 90 degrees from the wall?

My best guess would be to pull them out and toe them in to your sweet spot.
As for how much to pull the speakers in, the rule of thumb I've seen around is 2'. Of course, that might not be an option, but I'd try it.

I'll leave the the IB questions to the smart folks here .. I'll be in the same boat as you soon, or at least I hope I will.

JCD

[Chrisbee]

Wes

What you were suggesting in your picture is really an "outie" manifold. Whether the manifold is exposed or hidden you still need enough rear volume for the total number of drivers you use. The rear volume is your IB enclosure.

If you have easy access behind that wall I'd think about hiding your 4x 15" drivers in a conventional in-wall opposed-driver manifold. This is much more likely to satisfy your partner than an exposed box.

Then you cover the manifold opening with a colour-matched metal or wooden grill or a framed cloth grill. The grill will become instantly invisible if it's the same colour as the wall. So the actual grill size becomes a non-issue.

The IB will go into stealth mode and not take up any room in your HT. You will surprise everybody (including yourself) with your outstanding bass. Nobody will have a clue where all that bass is coming from. The drivers will also be safely hidden from curious sticky fingers.

If you'd really prefer to show off your drivers (and why not?) then by all means make a 2 x 2 opposed-driver "outie". If you want to see your drivers even better from your favourite seat then think about a two-sided manifold that sets the drivers at 45 degrees to the back wall. You won't get quite the cancellation of an opposed driver manifold but it will be better than an array without taking up all the all space of a vertical array. Arrays don't have to be either vertical or horizontal. They can also be blocks of drivers if it suits the situation better. Here's a couple of quick ideas.



Pointing the drivers into the room or at the listening position or even away from you really won't make any noticeable difference. Nor will facing them opposite ways on an "outie" manifold. Provided you have all your drivers in phase they don't care which way they face. They'll still do their bass thing.

Bass is non-directional if crossed over below 80Hz. Your speakers look easily capable of an 80Hz crossover to your IB with loads of free extra headroom.

4 x 15" PE drivers should blow you away. The PEs are close to my AE IB15s and my 4 can easily manage incredible bass.

If 4 x 15" don't satisfy then just add more drivers in pairs as funds allow. They don't all have to be driven by the same amp or the same channel on a two channel amp. Just keep them all in phase and ensure you have enough volume behind the manifold wall to take all that backwave.

All the longthrow drivers give you is more swept volume per driver. So the manifold can be more compact because you need fewer drivers for the same effect. You can easily make up for this with the PE drivers just by adding more until you are satisfied. It just takes up a bit more room, that's all. Which hardly matters if the manifold is hidden out of sight. If you do have your drivers visible then you get to show off more big drivers than the guy running just two longthrow 15 inchers.

[Wes Whitmore]

Chrisbee,
All good stuff and very helpful. That drawing was actually intended to represent the hidden manifold design. I should have labeled it! That is my HVAC room under the stairs where my single 15 currently resides, and fires through that metal grill. I definately have to keep the subs out of the room if possible (per the wife), but I don't know if I want to just frame in the "innie" so I can see the woofers working, or keep a grill on it. I guess I can always just do a removable grill. Right now most people actually think that grill is part of the house A/C system...

Thanks for all of the input. Your 45 degree innie would be a pretty cool thing too.

Thanks,
Wes