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For those who have listened to IB subs.... - Page 2

post #31 of 428
Quote:
Originally Posted by RyguyOK View Post

Thanks for all the input. I didn't even know Thomas W had an AVS account

Even after lurking for quite a few hours at the Cult website over the past few years, I still have learned a few things in this thread. Part of what I've been mulling over, was whether to go with a THT in the near future, or save up and go with an IB further down the line. I think I will end up going with an IB, but if the right opportunity presents itself I'd love to try a THT. We shall see....

It comes down to two things.

Do you want big boxes in room?

Do you want < 20Hz output?
post #32 of 428
Quote:
Originally Posted by soho54 View Post

Who said anything about air loss?

What does where I live have to do with anything? I have lived in a home covered with snow at -18deg temps with single pane windows. In the military I lived in several places with those conditions, as well. What does that prove? Nothing.

Have you heard of anyone putting in an IB, and taking a hit on the heating bill?

Probably will not have air loss, but you sure will have thermal loss if your IB is in your attic. You can't insulate it so basically you have an uninsulated space in your ceiling. If the rest of your ceiling is R-40 or more this represents a fair amount of heat loss in the winter. The manifold would act so what like a chimney pulling the heat out of your house. An IB into the attic would have to increase your heating bill if you live in a cold climate. The question is how much.
post #33 of 428
Quote:
Originally Posted by mjg100 View Post

Probably will not have air loss, but you sure will have thermal loss if your IB is in your attic. You can't insulate it so basically you have an uninsulated space in your ceiling. If the rest of your ceiling is R-40 or more this represents a fair amount of heat loss in the winter. The manifold would act so what like a chimney pulling the heat out of your house. An IB into the attic would have to increase your heating bill if you live in a cold climate. The question is how much.

You can place fibreglass over the entire system.

I can not feel cool air coming into my attic around my drivers and I can not feel the heat in my family room ceiling coming from the attic.
post #34 of 428
Quote:
Originally Posted by penngray View Post

You can place fibreglass over the entire system.

I can not feel cool air coming into my attic around my drivers and I can not feel the heat in my family room ceiling coming from the attic.

You are supposed to learn something new every day and I guess this is mine for the day. I did not know that you can insulate all around the manifold. How thick can the insulation be? My attic has over R-40. Anything less would be additional heat loss, but then the drivers are also making heat, so it may be heat gain while the system is running and heat loss when not running.
post #35 of 428
You can go as thick as you want...you are just laying the stuff over top, right ? As long as its not stopping the woofers then its not going to bother the drivers.
post #36 of 428
Quote:
Originally Posted by penngray View Post

You can go as thick as you want...you are just laying the stuff over top, right ? As long as its not stopping the woofers then its not going to bother the drivers.

A manifold would be a column running into your attic so to avoid heat loss you would need to cover the sides and the end. Can you cover the sids with R-40?
post #37 of 428
Quote:
Originally Posted by mjg100 View Post

Probably will not have air loss, but you sure will have thermal loss if your IB is in your attic. You can't insulate it so basically you have an uninsulated space in your ceiling. If the rest of your ceiling is R-40 or more this represents a fair amount of heat loss in the winter. The manifold would act so what like a chimney pulling the heat out of your house. An IB into the attic would have to increase your heating bill if you live in a cold climate. The question is how much.

You are making a mountain out of a mole hill. It is like the people obsessing over their attic doors. Spending $200 dollars on insulating door canopies to save ~$20 a year. Yeah, you saved $200 bucks over 20 years.

Go here (http://www.builditsolar.com/Referenc...s/HeatLoss.htm) and see for yourselves. Use the window input as your manifold area. Four 18"s will need an opening around 7sq ft.

Do one pass with the R value the same as your present ceiling, and then another at let's say R1.

For Kansas (the OPs location) I get an increase of $22 a year. If you change it to R2 it is a $10 a year increase.

Be honest, would you notice $1-2 increase in your heating bill? I know my bill fluctuates a lot more than that own it's own already. EDIT: Sorry that would be $3-6 for the cold months, as you don't have cold year round.

For full disclosure, where I live I get a $4 increase yearly with R1. The heat pump helps here.
post #38 of 428
Quote:
Originally Posted by mjg100 View Post

A manifold would be a column running into your attic so to avoid heat loss you would need to cover the sides and the end. Can you cover the sids with R-40?

You can wrap around the manifold on all sides, or you could bind some pieces together to drape over the manifold like a tarp, or table cloth.

The subs do not notice the fiberglass, as long as it doesn't touch the moving parts.
post #39 of 428
Quote:
Originally Posted by penngray View Post

It comes down to two things.

Do you want big boxes in room?

Do you want < 20Hz output?

How do IBs do with sound isolation? Do you have to isolate the room that is used as the baffle?
post #40 of 428
Quote:
Originally Posted by AndreasMergner View Post

How do IBs do with sound isolation? Do you have to isolate the room that is used as the baffle?

The sound in the forward and rear chambers are the same.

If you are trying to isolate the sound to a certain room, you will also need to isolate the rear room.

If you have never had a sub that can do infrasonics, don't be surprised when things still rattle on the other side of the house at spirited levels. Triple thick walls aren't enough here.

Flipping off the sub while the wife is asleep is still the best medicine.
post #41 of 428
First, I have to say, the term "box coloration" is about as vague (and silly) a notion as I've ever heard in a subwoofer discussion.

There's no such thing. ThomasW has attached discussion of system Q to the box coloration thing, but that's got nothing to do with the box and can easily be changed with EQ.

Assuming non linearities are at inaudible levels, what we hear is the FR.

As far as 'mid bass slam' (another humdinger) it's also a product of FR. IBs may have been built using high Le drivers, which may have lead to a dip in mid bass, but, again, that would be easily remedied with post EQ, given adequate system headroom.

I personally think the horn folks are hearing what an IB might sound like if it had a 25Hz HP in line. When you hear the full range of the movie soundtrack bandwidth for the first time, it will usually appear to take away from the mid bass area. Of course, that's not the case at all, as a FR magnitude graph would show. Adding the first few octaves adds a body to the presentation. Filtering those frequencies out may lead to subjective comments like 'tight', 'fast', 'mid bass slam', etc., but if FR, headroom and calibration are equal, there is no difference in the presentation.

My 4 little sealed sub system (40L of displacement/10KW) cleanly does mid bass to above 130dB at the LP, a level I'll never reach playing any source at any listening level I can conceive of calling sane. I don't know how using a different alignment to achieve the same headroom would introduce some magic different sound (because it wouldn't).

I agree with Penn. A properly designed IB will cover the LFE spec and with high quality signal shaping will offer infinite sonic signature through selectable F3, Q, crossover point, plenty of headroom, etc.

I also believe the same can be achieved with a system of multiple sealed subs, with some advantages an IB doesn't offer.

Bosso
post #42 of 428
How does someone determine the best place of the vent into the room for an IB? Do you just cut a hole in your room anywhere and expect to get a good FR? This is my concern of IB's.

I would have went IB's a long time ago but it is not an option for me atm.
post #43 of 428
Quote:
Originally Posted by DL86 View Post

How does someone determine the best place of the vent into the room for an IB? Do you just cut a hole in your room anywhere and expect to get a good FR? This is my concern of IB's.

I would have went IB's a long time ago but it is not an option for me atm.

Take your present sub, and position it in your listening position with the driver at ear level. Play some bass heavy tracks, or a test wave that sweeps from ~20-150Hz on repeat. Turn off any EQ you have going, and then walk around the room placing your head where you think the IB manifold mouth would be located. Of course you will need a ladder if a ceiling mounted IB is doable.

You will find some areas that are awful, and most places will sound OK. Just put the IB in one of the OK sounding places, and you should be good to go.
post #44 of 428
What? Hahahaha
Quote:
Originally Posted by bossobass View Post

First, I have to say, the term "box coloration" is about as vague (and silly) a notion as I've ever heard in a subwoofer discussion. There's no such thing.

Who used that "term" exactly?

I don't know about Thomas, but if you take a driver, and put it into three different enclosures, same alignment or not, you will get three different sounds. This is a no brainer. I don't care what you call it, they will sound different. To hear the driver alone you must raise the enclosure size to the infinite level, or go OB. There is no way to spin it. Saying "there is no such thing" is what is "silly."

In my head your post reads, "You would not hear a difference, or coloration. The enclosure doesn't effect the sound produced by the driver at all. Changing the enclosure only changes the Q. Nothing else could possibly change... and that is what... you... could hear... umm, but the Q change you heard had nothing to do with the enclosure used. It was caused by... something else... unrelated to the enclosure, of course. Therefore the enclosure has no effect on sound. You can hear a FR change, but that is something else unrelated to the enclosure change the Q, and you can fix it with EQ if you feel like it anyway, so it doesn't exist." Come on.

Tell you what, lets ignore subjective for a moment, name one measurable parameter that doesn't change when altering an enclosure.

Moving on, so someone needing more "mid bass slam" is a joke... but if someone somehow had a lack of "mid bass slam" for whatever wacky reason they could add EQ in your opinion to correct it? OK. How is it a "humdinger" again, or any different from what has been said here already?

It seems like the whole point of your post was just to toot your "my multiple small sealed subs do everything better in every possible situation, than anything else in the world" horn.

You are starting to sound like Stevie with LLTs.
post #45 of 428
Quote:
Originally Posted by AndreasMergner View Post

How do IBs do with sound isolation? Do you have to isolate the room that is used as the baffle?

Someone else posted this already but unless you have subs in a sound proof room you are going to have bass throughout your house with any design.

The IB does have a rear wave that goes throw my attic, mine is close to my two little girls rooms so. I actually do not use it as much as I use too. I wouldnt use a subwoofer in the family room either for the same reason.

I do have two ported subs (15" TC2Ks, 11 cuft boxes) in my HT room, Im still pretty happy with those too. If I redesign the room, I would love to built DTS-10. I was not ready for it when it was around $1K though

I think sometimes we lose prespective in these discussions. We should keep reminding ourselves that ALL these solutions give us incredible bass beyond what any average person has.

We just have to choose which design works the best for us.
post #46 of 428
I'd love to hear a good IB setup. Anyone near-ish to Albany, NY or Fall River, MA? Please PM me.

Would it be dumb to try and get some of the <20 hz frequencies through a butt kicker type product? Seems like it would require much less power and sound transmission wouldn't be as big an issue. That is assuming you have a butt kicker that goes down to 5-10 hz. You'd be sitting down for movies anyway. I know it wouldn't be quite the same, but maybe 80%? 50%? 10%?

I really haven't had the experience with either product, so don't be too hard on me!

soho: I think bossobass might have been mostly referring to mynmyn's post where he thought the IBs he has heard lacked midbass. I think bossobass' point was that when you have enough drivers and power to get the low frequencies, the midbass frequencies should be well covered, and if not you can certainly EQ them to get more than you want.
post #47 of 428
Quote:
Originally Posted by penngray View Post

Someone else posted this already but unless you have subs in a sound proof room you are going to have bass throughout your house with any design.

I'm planning a dedicated HT and wanted to sound proof it. We have a baby on the way and the neighbors' house 8 feet away, so it's almost a necessity if I want to be able to use the space freely. It seems like using IBs might require me to make TWO sound proofed rooms.
Quote:
Originally Posted by penngray View Post

The IB does have a rear wave that goes throw my attic, mine is close to my two little girls rooms so. I actually do not use it as much as I use too. I wouldnt use a subwoofer in the family room either for the same reason.

I do have two ported subs (15" TC2Ks, 11 cuft boxes) in my HT room, Im still pretty happy with those too. If I redesign the room, I would love to built DTS-10. I was not ready for it when it was around $1K though

There's always the THT, although it doesn't go quite as deep.
Quote:
Originally Posted by penngray View Post

I think sometimes we lose prespective in these discussions. We should keep reminding ourselves that ALL these solutions give us incredible bass beyond what any average person has.

We just have to choose which design works the best for us.

Definitely true! I'm very happy with my THT right now, but wonder if and what I'm missing! All I know is that I was pretty happy with my previous sub (10" ported with a lot of output *above* 50 hz). Now I have more output and lower than at least 99.9% of people out there.

Now if I wanted serious low bass, I would just make a rotary subwoofer! I think I could make one in a weekend. I think sound isolation would go out the window though.
post #48 of 428
Quote:
Originally Posted by AndreasMergner View Post

I'd love to hear a good IB setup. Anyone near-ish to Albany, NY or Fall River, MA? Please PM me.

Would it be dumb to try and get some of the <20 hz frequencies through a butt kicker type product? Seems like it would require much less power and sound transmission wouldn't be as big an issue. That is assuming you have a butt kicker that goes down to 5-10 hz. You'd be sitting down for movies anyway. I know it wouldn't be quite the same, but maybe 80%? 50%? 10%?

I really haven't had the experience with either product, so don't be too hard on me!

< 20Hz is not really about shaking. Shaking can be great with > 20Hz content. What a few people experience down low is compression. Its a completely different sensation and the first time I was exposed to it I said "WHAT THE F**K WAS THAT", Ever since then I just want it.

I do have butkickers also and I like them in addition to my setup. They are not a replacement for utlra low frequency compression but they are better then nothing.

Disclaimer, I do not care if its 2 movies out of 1000 that have it. Im posting this hoping we do not slide into a < 20Hz content debate.


Quote:



soho: I think bossobass might have been mostly referring to mynmyn's post where he thought the IBs he has heard lacked midbass. I think bossobass' point was that when you have enough drivers and power to get the low frequencies, the midbass frequencies should be well covered, and if not you can certainly EQ them to get more than you want.

Yep, Bosso is posting that having 8 drivers in sealed designs, EQed with tons of power is more the less the same as an IB with less EQing requirements and less power requirements. There are many ways to obtain the same deep response. Bosso also posted a great comment about overall bass response. People actually think sometimes there is a "lacking" mid range because they are just very use to having > 25Hz bumped up. When you include lower frequencies there is a better overall balance to the setup. You hear the first time and you wonder if something is wrong, you hear it the 30th time and then go back to a > 25Hz system and you think the bass is bloated more.
post #49 of 428
I have listened to a number of infinite baffle set ups and the quality of sound reproduction was completely different to any acoustic suspension set up I've heard.

Now one could chalk this up to a lack of box coloration, or the fact that the air spring in such an environment has almost zero effect on the mechanical suspension of the driver. Who knows. I'm not a physicist for real but I play one on this forum and I'll be damned if I haven't done a fantastic job thus far.

If the past is any indication, Noah is going to post right after I've finished my rant and ridicule me for some or other reason. Continue.
post #50 of 428
Its been a while goneten, its always great to read a post from you
post #51 of 428
Howdy penngray. I was banned for while because I made fun of Dr Earl Geddes subwoofer theories. I see you have more than quadrupled your post count.....and thanks.
post #52 of 428
I don't know what post you guys were reading.
post #53 of 428
So the box is relevant?

Bossobass waved his hand and it didn't matter for a moment.
post #54 of 428
Quote:
Originally Posted by Soho54 View Post

I don't know what post you guys were reading.

I'm not sure either.
post #55 of 428
Quote:
Originally Posted by soho54 View Post

What? Hahahaha
Who used that "term" exactly?

I don't know about Thomas, but if you take a driver, and put it into three different enclosures, same alignment or not, you will get three different sounds. This is a no brainer. I don't care what you call it, they will sound different. To hear the driver alone you must raise the enclosure size to the infinite level, or go OB. There is no way to spin it. Saying "there is no such thing" is what is "silly."

In my head your post reads, "You would not hear a difference, or coloration. The enclosure doesn't effect the sound produced by the driver at all. Changing the enclosure only changes the Q. Nothing else could possibly change... and that is what... you... could hear... umm, but the Q change you heard had nothing to do with the enclosure used. It was caused by... something else... unrelated to the enclosure, of course. Therefore the enclosure has no effect on sound. You can hear a FR change, but that is something else unrelated to the enclosure change the Q, and you can fix it with EQ if you feel like it anyway, so it doesn't exist." Come on.

Tell you what, lets ignore subjective for a moment, name one measurable parameter that doesn't change when altering an enclosure.

Moving on, so someone needing more "mid bass slam" is a joke... but if someone somehow had a lack of "mid bass slam" for whatever wacky reason they could add EQ in your opinion to correct it? OK. How is it a "humdinger" again, or any different from what has been said here already?

It seems like the whole point of your post was just to toot your "my multiple small sealed subs do everything better in every possible situation, than anything else in the world" horn.

You are starting to sound like Stevie with LLTs.

First things first:

Quote:


By SQ I mean playback uncolored by the enclosure

You said it, exactly. It's what prompted my response. I've read it many times. It's as incorrect every time I read it.

I think it's the "In my head, your post reads..." part that's giving you a comprehension problem. Try maybe having someone read it to you.

I'll try to make it as simple as I can for you...

There is only one alignment that can achieve this in-room FR with headroom and inaudible non-linearities:


The following graph is of one subwoofer. You can knock yourself out as to which is the native response and what that might mean to your box coloration theory, especially if this graph were of an IB.


Since each of those FRs evokes a different set of subjective comments, where does the 'coloration from an enclosure' idea factor in?

Since a sealed system includes an IB system and the FR can be matched using any properly designed sealed system, coloration from the enclosure is BS.

Here's the point, and sorry I can't type it slower for you; given the same FR with the same lack of non linearities and the same headroom, the presentation will be the same and will be perceived as the same and described similarly.

Yes, I've tooted that horn for a long time, mostly because experts like yourself keep posting nonsense to the contrary.

MKT (who, for the record, I think is one of the coolest cats ever) has referred to 'the horn sound' in comparisons of different alignments in his theater. His opinion matters more than most posters because he's graphed and compared ported, LLT, sealed and TH in the same room, but I argued that there is no such thing as a 'horn sound'. Although MKT's measurement hardware is less than ideal, there is still good evidence in that there is a relative comparison to be observed. There was only a significant FR difference at the LP between them, nothing more.

It wasn't box coloration. It wasn't the horn sound. It wasn't mid bass slam.

Danley attempted to defend the 'horn sound' theory as being attributable to lower group delay. Since GD is a derivative of FR, this was shown to be an incorrect theory, although that probably won't stop experts from arguing otherwise.

Getting back OT, there are 4 disadvantages to the IB vs a boxed sealed system; 1) when the ambient temperature can vary from 45 degrees to 130 degrees, performance is affected. E-mail Ilkka and ask him what comparative value his measurements would have if the ambient temp varied that much from test to test. 2) An IB can't properly use the corner(s) of a room. 3) Placement tweaks are not possible. 4) Mid bass potential must be limited or HP filter protection must be employed, there's no getting around it.

On an unrelated note, for the record, I don't consider your childish reference to Steve Callas as the slight you intended it to be. Steve has had a lot more to add to the hobby than your condescending blurts.

goneten,

I too am glad to see you back posting.

Bosso
post #56 of 428
Thanks Bossobass. It's good to see you posting too. I would be interested to hear Thomas W's perspective although he may be just a tad bit biased. I'm somewhat biased myself.

Just as a matter of interest, have you ever heard an IB before ? BTW, good luck with the World Cup. At least our team scored a goal which is a heck of a lot more than I was expecting to be honest.
post #57 of 428
Quote:
Originally Posted by Bossobass View Post

2) An IB can't properly use the corner(s) of a room.

Could you elaborate a bit more on this ? What if one constructed a manafold and simply positioned it in the corner (whether it be an attic or crawlspace) ? Wouldn't that give corner loading benefits ?
post #58 of 428
Quote:
Originally Posted by goneten View Post

Thanks Bossobass. It's good to see you posting too. I would be interested to hear Thomas W's perspective although he may be just a tad bit biased. I'm somewhat biased myself.

Just as a matter of interest, have you ever heard an IB before ? BTW, good luck with the World Cup. At least our team scored a goal which is a heck of a lot more than I was expecting to be honest.

I consider ThomasW to be THE guy to ask about IB. We may disagree on this particular facet, but I respect his opinions more than anyone else regarding the ins and outs of IB.

Yes, over the past 20 years I've had pro sound, ported, LLT (although SC doesn't think my LLTs qualified as LLTs), sealed, sealed/LT'd, BP and IB. I've experimented with 50+ drivers and nearly infinite signal chain combinations.

Bosso
post #59 of 428
Quote:
Originally Posted by goneten View Post

Could you elaborate a bit more on this ? What if one constructed a manafold and simply positioned it in the corner (whether it be an attic or crawlspace) ? Wouldn't that give corner loading benefits ?

Yes, it would. Do you know of any examples?

Bosso
post #60 of 428
Quote:
Originally Posted by bossobass View Post

Since a sealed system includes an IB system and the FR can be matched using any properly designed sealed system, coloration from the enclosure is BS.

Here's the point, given the same FR with the same lack of non linearities and the same headroom, the presentation will be the same and will be perceived as the same and described similarly.

Bosso

I disagree with the first statement. The effects may not be as drastic as many would like to think, but I don't agree that they don't exist entirely. The reason is that you cannot assume the same set of non linearities and headroom regardless of the enclosure (not talking about just IB or sealed here). The enclosure affects these drastically in some cases. 2 FR's that are nearly exactly the same will likely sound very close to each other if not indistinguishable provided that both systems are well within their limits, however a horn subwoofer and an IB using the same drivers may have different energy decay rates, the loading on the drivers may cause huge variations on efficiency relative to each other, different distortion profiles, system self noise, thermal effects on the motor, etc, so perhaps a small difference could still be heard when you add all of these differences together. Granted the difference between a sealed sub and an IB would be much smaller than that between a sealed vs ported, or horn comparison, but assuming that ideally each alignment should be capable of covering 12-120hz if developed right and that each was filtered with the same final acoustic xovers and that the FR's, placement and levels were matched, you do not believe that there would be a notable difference to hear between any of these alignments? Something that could reliably be picked in a blind test? I am not so sure. I think that energy storage or lack there of and the distortion profile could provide changes in the signature. Even comparing uber capable systems that are just coasting.
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