Initial disappointment with IB

**solid7** · **04-07-08, 11:18 AM**

I've had my dual RL-P15 IB up and running for a couple of months now. Although I haven't had a chance to run REW yet, (as I don't have the time, knowledge, or equipment right now) it sounds pretty good. Only problem is, it doesn't quite "feel" like I would have expected.

Our house is tile over slab, and we have a large open floor plan. I suspect this contributes a great deal to my lack of "feeling". However, more notably, I remember that my old cheap sub - part of a JVC home theater in a box kit - seemed to have more "feel" per capita than this beast. Don't get me wrong - it blasts out the sound - but I don't want to just hear it - I really want to feel it. I suspect that ported sub standing in the front corner of the listening area would be the answer to this dilemma. Am I correct, or way off base?

Unfortunately, I have to use the short distance across the room for my listening area. To the left of my listening position, the room opens up into the rest of the house. This is why I suspect that a corner loaded sub would favor the room, but I'm certainly no acoustic expert.

Any advice is appreciated.

EP2500 amp
BFD (not yet dialed in)
Denon 2308 receiver

**willy-be** · **04-07-08, 11:34 AM**

Your old JVC was a boom box. If you want an IB to sound like that use an equalizer to dial in as much boom as you want.

Quote:

but I don't want to just hear it - I really want to feel it

This makes no sense given your preference for the JVC. It couldn't couldn't possibly reproduce the low frequencies responsible for bass you feel.

You really need to use EQ Wizard to make some measurements of the sub. That's the only way to know what's going on..

Aloha,
WB

**solid7** · **04-07-08, 11:39 AM**

I had no preference for the other sub - only expectations for the new one. Mind you, I said more feel "per capita" - as in, it seemed to pack more punch, ounce for ounce. But as you say, it was boomy, which is what I've always hated about ported boxes. (at least the ones that I have had experience with)

REW is coming. I'm still learning (via FAQ, and not asking) what materials I need to gather to make it possible. I'm work 60+ hours every week, so I'm a bit short-handed on time.

**willy-be** · **04-07-08, 11:58 AM**

HTIB subs are tuned to have a bunch of output at a pretty high frequency. Higher frequencies are where boom exists. Frequencies you feel are much lower, and can't possibly be reproduced by a HTIB sub.

If you still have the old sub, measure it's output at the listening position as a basis for comparison.

Aloha,
WB

**Sonnie** · **04-07-08, 01:28 PM**

As WB suggest, it is very difficult to tell what might be going on without some measurement graphs, although it sounds like a lack of low-end.

Any sub can sound boomy, it does not have to be ported. I have three ported subs in my room, no boom at all... just excellent extension with massive impact and feel.

**solid7** · **04-07-08, 01:36 PM**

I won't try to overly criticize or brag on this system until I can manage to get REW configured and running. I have to be honest, I'm out of my element, and with short time, and lack of knowledge, it's been a bit of a task for me to get up to speed. However, I assure you, those graphs will come.

As for the low end - there is some really great low end. I know it's there, because the *really* low stuff can be felt. But again, not as well as I would have liked. Maybe it's me being overly optimistic, (unrealistic) or perhaps it's the fact that I had some insane car audio systems when I was much younger. I remember what that experience was like, and obviously, I'm not going to have the same experience in a viewing room as I would in the much smaller interior of an automobile. However, I want to get closer to having the sub be much more of a "physical" experience.

More to come. Thanks for your replies so far, guys...

**willy-be** · **04-07-08, 02:01 PM**

Some of what you're saying is a little confusing.

Quote:

As for the low end - there is some really great low end. I know it's there, because the *really* low stuff can be felt

Quote:

However, I want to get closer to having the sub be much more of a "physical" experience.

The frequencies creating pounding chest compression are higher in the spectrum than what most people expect. If you want chest compression effects dial in some boost in the 40Hz-80Hz range.

Aloha,
WB

**solid7** · **04-07-08, 02:58 PM**

Not confusing for me. Being able to feel some notes doesn't mean that I can feel them the way that I want to be able to...

**imbeaujp** · **04-07-08, 04:44 PM**

Hello, What is your crossover frequency ? Have you tried low frequency like 40-60Hz with some high gain ?

JP

**thxgoon** · **04-07-08, 08:27 PM**

A lot of that 'punch' you felt from your JVC sub and likely your car subs were due to much higher harmonic distortion than you have in your current system. This distortion can give the illusion of tighter or punchier sound. In a sense when these subs are called on to play one note, they play 5 and the percieved loudness is greater. By comparison your IB is one of the cleanest and lowerst distortion designs you can build. An REW graph would definitely help to see what is happening though.

**solid7** · **04-07-08, 08:40 PM**

No, I haven't really tried anything like that yet. I have it set to +0 db on the LFE, but since I'm not EQ'ed yet, I really haven't had the nerve to change it yet. When I experimented with LFE gain, it got a little muddy for my liking.

I tried some of the recommended viewing for new sub owners. (Transformers, Lord of the Rings, Pirates of the Caribbean, etc.) Again - and I can't emphasize enough - there was really nice bass in a lot of scenes. However, either I have unrealistic expectations, or I suffer from a lack of sensitivity to bass, due to past abuse.

I would like to take the opportunity at this point to ask someone out there to help me make sense of the REW gear required. I know that I need an SPL meter, and I need a full duplex sound card. But I'm not sure what else that I need to interface directly with the BFD. I've read the FAQ, and seen the schematic for hooking up the hardware - but I'm having some sort of a brain fart on this. I don't want to clutter up the forum with silly questions. If anyone is willing to PM me, and offer me a little direction, I'd certainly be more than happy to accept it.

Sorry - almost forgot to answer the question - I'm crossed over at 80 Hz.

**thxgoon** · **04-07-08, 08:58 PM**

How did you go about calibrating a level for the subs now?

Other than an SPL meter and sound card you don't need much else. REW will spit out filters that you can input into the BFD by hand if you don't want to mess with the hardware. It's pretty easy once you figure it out.

**a1161979** · **04-07-08, 09:03 PM**

Quote:

solid7 wrote:

No, I haven't really tried anything like that yet. I have it set to +0 db on the LFE, but since I'm not EQ'ed yet, I really haven't had the nerve to change it yet. When I experimented with LFE gain, it got a little muddy for my liking.

I tried some of the recommended viewing for new sub owners. (Transformers, Lord of the Rings, Pirates of the Caribbean, etc.) Again - and I can't emphasize enough - there was really nice bass in a lot of scenes. However, either I have unrealistic expectations, or I suffer from a lack of sensitivity to bass, due to past abuse.

I would like to take the opportunity at this point to ask someone out there to help me make sense of the REW gear required. I know that I need an SPL meter, and I need a full duplex sound card. But I'm not sure what else that I need to interface directly with the BFD. I've read the FAQ, and seen the schematic for hooking up the hardware - but I'm having some sort of a brain fart on this. I don't want to clutter up the forum with silly questions. If anyone is willing to PM me, and offer me a little direction, I'd certainly be more than happy to accept it.

Sorry - almost forgot to answer the question - I'm crossed over at 80 Hz.

Maybe im being out there but it seems to me you think an IB is build and forget kinda like buying a JVC sub and throwing it in the corner

It is going to take a lot of buggering around with settings such as gain, EQ and crossover to get it soulding to your tastes... There is simply no way that a JVC sub can be outperforming dual IB RLP15's, unless something is really wrong, is it an array or a manifold? Maybe something is wrong with the IB? Have you checked phase and amp settings?

Once again maybe a little harsh but why build an IB if you havent bothered to figure out how to use REW yet? We are going to need to see some graphs to help use here. As for the 60 hour week

hope they pay you well cause that would kill me

The best advice i can give is check everything... Everything... form the amp to the drivers wiring etc to make sure everything is running fine, if it is then get REW up and running ASAP and show us some graphs

Oh and pictures are always great

**solid7** · **04-07-08, 09:24 PM**

Wow - I'm not quite sure how this thread got so confused. We have people assuming that I somehow think the JVC sub was better than the IB, and that I thought the IB was "plug and play". Please, make no mistake - that's not what I've said. I do plan to get some equipment, and use REW to fine tune the setup. There has been NOTHING done so far, simply because I'm in a learning mode, and have not had a chance to sort out what I need, or a time to acquire it.

The IB sounds good, but I have (evidently) a preconceived notion of what my starting point should be, and this isn't exactly it. I think I need to disengage from this thread until I have had a real chance to figure out my next step with the BFD.

I do appreciate the help so far, though.

Quote:

were due to much higher harmonic distortion than you have in your current system.

No, not likely, at all. I had 4 12" Kicker Solo-Baric subs, with an 18" Cerwin Vega in the back of a GMC Jimmy. Maybe it shows my age, but at the time, this was a serious monster. (capable of making people sick, proven several tiems over)

Quote:

Once again maybe a little harsh but why build an IB if you havent bothered to figure out how to use REW yet?

Because the IB sub was perfect for my room - out of sight, and no wires to trip over. Maybe a stupid reason, but it was a winner for me. Plus, I don't like giant enclosures.

Quote:

As for the 60 hour week hope they pay you well cause that would kill me

60 hours is my minimum week. I've been all the way up to 100+, with the median being around 75. I am self employed, so there is plenty of motivation to work hard. And yes, I'm paid quite well.

Quote:

The best advice i can give is check everything... Everything... form the amp to the drivers wiring etc to make sure everything is running fine, if it is then get REW up and running ASAP and show us some graphs

Yeah, everything is working good. I want to interface directly with the BFD via my laptop, (as little manual work as possible) and I'm having a rough time trying to figure out which MIDI inteface to use. I'm trying to be cheap, telling myself that I will only use this a few times. But to be honest, I have no idea how to make a good buying decision on this equipment. I've read threads on different modules, but just can't bring myself to part with the required cash. A character flaw that I'll overcome eventually, I'm sure...

**thxgoon** · **04-07-08, 09:38 PM**

Quote:

solid7 wrote:

I want to interface directly with the BFD via my laptop, (as little manual work as possible) and I'm having a rough time trying to figure out which MIDI inteface to use. I'm trying to be cheap, telling myself that I will only use this a few times.

For now just use the headphone out and line in on your laptop. Run a calibration file on your soundcard that will get you close.

How did you set your levels on your sub currently? My guess is if you used your built in test tones from the receiver there may be a large peak somewhere in your room response causing you to turn the entire thing down to achieve proper levels taking the rest of the bass with it. Harmonic distortion is likely a factor that your small JVC sub that gave you the false impression of punchier response. If it's asked to play 30hz, it'll also play 45 and 60 hz, and both of those frequencies are in the 'punch' range. Placing it in the corner could have made this worse. It sounds like your car system is different than my experience. Most I know of are tuned above 30 hz and for max SPL over low distortion.

**Sonnie** · **04-07-08, 09:42 PM**

How big is your room? I wonder if a 2 driver IB is even enough. Generally we see 4 subs and sometimes more. That may be the issue.

**Otto** · **04-07-08, 09:45 PM**

Hey there,

Yeah, sounds like you need to get the BFD working. The IB is a different animal, and has a slightly different sound to it than other subs (to some degree, at least). I also think that I used to get more "boom" out of my old box subs. To me, the IB just has a presence to it. It's there, and it can be subtle (i.e., not boomy), and it blends nicely with the rest of the sound, be it music or movies. Now, when it needs to, the IB can get scary loud and actually shake the walls (seriously, I have never turned mine "all the way up" because it's just too much, walls and windows are visibly shaking and audibly rattling). Anyway, yeah, I hear what you are saying. Now, I've tuned my IB using REW and a BFD and it integrates well and sounds good...

As to USB soundcards, here's a thread that offers some ideas. I don't use a USB soundcard, so I don't know which one's good and which one's not. Still, I think any reputable manufacturer's model will work. There have been some warnings that some cards don't support Vista well, so if you're a Vista user, that may be a concern. If you're not a Vista user, I think you should be pretty safe as far as drivers go. Also, Vista's been out long enough that there may be better driver support at this time.

As you noted, you'll need an SPL meter of some sort. The Radio Shack models are popular, and we here at the Shack have the calibration files for all flavors of the RS meter. The Galaxy CM-130 is a nicer meter and I'm sure you can find one on eBay or elsewhere online.

You will need to connect the meter to the sound card. Depending on the type of meter, you may need one connection or another. The output of the RS meter is a normal mono RCA plug. The output of the Galaxy is a 1/8" headphone style jack (I would guess it's mono, but I can't quite recall now). You'll feed that cable (from the SPL meter) to the soundcard. If the soundcard doesn't accept that type of connector natively, you'll need an adapter. They will have them at RS. A common one we use is a L/R RCA (will accept the signal from an RS SPL meter) to stereo 1/8" (goes into the sound card).

From the sound card to the receiver/preamp is probably another 1/8" stereo jack to L/R RCA jacks.

Hey, I should have known better, but there's a thread here that really describes all this pretty well. Let us know if that doesn't answer connection questions.

Good luck!

**a1161979** · **04-08-08, 01:12 AM**

Quote:

solid7 wrote:

No, not likely, at all. I had 4 12" Kicker Solo-Baric subs, with an 18" Cerwin Vega in the back of a GMC Jimmy. Maybe it shows my age, but at the time, this was a serious monster. (capable of making people sick, proven several tiems over)

Your going to have to leave your notions about bass behind... Honestly bass in a car is a totally different task to bass in a Home Theater, i doubt two 18 LLT's could come close to the feeling of a single 10 or 12 in a well designed box in a hatch back

Just as i started from scratch comming from CA to HT you will need to also... As for the 18 CV well

**solid7** · **04-08-08, 11:20 AM**

Quote:

a1161979 wrote:

Your going to have to leave your notions about bass behind... Honestly bass in a car is a totally different task to bass in a Home Theater, i doubt two 18 LLT's could come close to the feeling of a single 10 or 12 in a well designed box in a hatch back

I have no doubt that the feel and general experience in car audio is a world apart from HT. It's most likely part of my problem. It's been many years since I've had CA, but I can still feel my teeth chattering, until my jaw drew tight. Once you've had a taste of that - assuming that you enjoyed the experience - it's hard not to demand more, more, more...

Quote:

a1161979 wrote:

Just as i started from scratch comming from CA to HT you will need to also... As for the 18 CV well

I haven't had any CA experience for over 10 years. However, I remember that feeling.

I may not be a smart man - but I know what bass is... (a variation on a theme)

**atledreier** · **04-08-08, 01:12 PM**

So maybe you should have built some small-ish ported enclosures to your drivers instead? You should be able to produce some tremendous SPL like in a car with a tuning of 30Hz on a couple of RL-p15s.

**solid7** · **04-08-08, 03:12 PM**

At what cost can I build small subs with massive SPL? (quality wise) Where do I find more information on this subject?

Thank you.

**a1161979** · **04-08-08, 10:33 PM**

Quote:

solid7 wrote:

I may not be a smart man - but I know what bass is... (a variation on a theme)

I also love CA but take you CA sub out and lug it into your theater and see how it performes... You would need an airtight room with 10+ 18Inch subs to replicate car bass...

Gives me ideas

As for remembering that feeling, your never going to forget it

Now if you think you know what bass is go and get a CA woofer in CA box (or your neighbours sony sub/jvc) and watch war of the worlds... Now plug the ib back in and there should be a HUGE difference is bass... like

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