Will it hurt to make a cabinet design a tad bit slimmer?

[seawalker]

I notice a lot of designers state that their speaker will work in a parts express cabinet, which might not be the exact same volume and baffle size as the original cabinet built, but pretty close.

Given this flexibility I'd like to make a cabinet that is a little slimmer, maybe by a 1/2 inch on each side. To compensate I guess I would make the cabinet taller by 1 inch. I guess that would keep the volume equal? Take for example the parts express .25 cu cabinet and the Dreydel or Continuum desifn. For mostly aesthetic reasons I would like the baffle a little slimmer. Will this throw off the sound of a design?

Thanks

[WernerM]

I notice a lot of designers state that their speaker will work in a parts express cabinet, which might not be the exact same volume and baffle size as the original cabinet built, but pretty close.

Given this flexibility I'd like to make a cabinet that is a little slimmer, maybe by a 1/2 inch on each side. To compensate I guess I would make the cabinet taller by 1 inch. I guess that would keep the volume equal? Take for example the parts express .25 cu cabinet and the Dreydel or Continuum desifn. For mostly aesthetic reasons I would like the baffle a little slimmer. Will this throw off the sound of a design?

Thanks

Making a baffle slimmer, and taller than the original design, means reworking the crossover for BDS (baffle diffraction), and Baffle step. It may not be noticable, but then again, it could be very noticable. You would need to model it to see. But if you do this, and you model a box with the slimmer sides, and increase the height of the box to supplement, that should be fine. However don't assume that losing 1/2" all the way around and increasing 1" height will correct for the volume, you need to model it.

[Whitneyville1]

Well, it may take a different amount to get the same volume, but there are volume calculators for that. The answer to your question is "probably it's OK". If the woofer gets too close to the sides, it will affect the sound. We're dancing with the Devil here. The smaller the speaker, the more critical following the build becomes, unless the designer says otherwise, or you're willing to chance building at least one enclosure that won't work. I'm sorry, I should know, but off the top of my head, I don't remember who designed either of those speakers (Paul C. or Lou C.?) but they'll be glad to assist you. Welcome and Best of luck. -Ricky-Pooh

[donradick]

I tend to agree that the difference won't really be noticable, but both of the designs listed by the OP are highly-regarded, darn near
perfect designs. I would suggest not changing anything if so you can hear the best results.

I've seen many posts like this - the usual answer is that 1/2 inch or even 3/4 inch is no big deal.
In this case, the baffles are already pretty narrow, and the OP wants to reduce by 1 full inch.
I wouldn't mess with prefection.

[jsr]

1/2" total won't make an audible difference. I personally don't think I can hear the difference with a 3/4" total reduction. 1" I think may get into the audible difference realm, however I think it would only be noticeable if you heard an unmodified version side by side with your narrow version. I'd recommend going with 3/4" total reduction max.

[Whitneyville1]

Don and Marc, (Marc, you type faster than me) we all say the same thing. That's dangerous. We're either semi-correct, or spending WAY too much time around each other. Don, is it as bad in Hotlanta as Tussa? We're in the middle of a major drought and hit 107 officially at the airport (the coolest spot in town, really) Saturday. I'm ready for a DIY speaker get-together 2" South of the Canadian border in Idaho or Montana (Glacier National Park). Ricky-Pooh

[fastbike1]

I'm with Don. The Continuum's in particular were designed and voiced for some pretty specific characteristics by a designer that really understands the details. It's always the builder's build, but in this case I think it's a mistake to alter the baffle. For this baffle, 1" is beyond the typical rule of thumb, and I don't think the rule of thumb applies when the design is so specific.

1/2" total won't make an audible difference. I personally don't think I can hear the difference with a 3/4" total reduction. 1" I think may get into the audible difference realm, however I think it would only be noticeable if you heard an unmodified version side by side with your narrow version. I'd recommend going with 3/4" total reduction max.

[Whitneyville1]

I'd absolutely leave Jeff Bagby's Continuum design alone. Jeff is so precise with his designs, any change will change what he intended, if subtly, or greatly.

[donradick]

Don and Marc, (Marc, you type faster than me) we all say the same thing. That's dangerous. We're either semi-correct, or spending WAY too much time around each other. Don, is it as bad in Hotlanta as Tussa? We're in the middle of a major drought and hit 107 officially at the airport (the coolest spot in town, really) Saturday. I'm ready for a DIY speaker get-together 2" South of the Canadian border in Idaho or Montana (Glacier National Park). Ricky-Pooh

OT fur shur, dude!
HotLanta ain't been too bad, compared to the midwest. We hit a few days at 104-106, but we're back down to a measly 94-98 at present.
Basement is still too hot for building speakers, but I do it anyways.

[seawalker]

Thanks to all for the insight. If I do the continuums I'll definitely leave them alone, and most likely any other as well. I have a pair of little Totem monitors and like there slender appearance.

Could I get away with 50 watts with the continuum's 83db is the question. Ideally I'd like more.

[dthomas]

I notice a lot of designers state that their speaker will work in a parts express cabinet, which might not be the exact same volume and baffle size as the original cabinet built, but pretty close.

Given this flexibility I'd like to make a cabinet that is a little slimmer, maybe by a 1/2 inch on each side. To compensate I guess I would make the cabinet taller by 1 inch. I guess that would keep the volume equal? Take for example the parts express .25 cu cabinet and the Dreydel or Continuum desifn. For mostly aesthetic reasons I would like the baffle a little slimmer. Will this throw off the sound of a design?

Thanks

A 1/2" on each side is 1" narrower I assume?

I would want to remodel it to see what the difference is. You would be affecting the region 500 to 600Hz down by as much as a db or so. So while it might not be drastic or a deal breaker it is definitely likely to be audible compared to a design done with the correct baffle dimensions. Altering the volume of the cabinet will further effect the low frequency performance. So if you are after a speaker that sounds like one of these designs your desired changes are working against that goal.

I kind of struggle to see why a cabinet 1" narrower and 1" taller would be aesthetically really much different. Also since the cabinet is a rectangle taking away 1" from the width won't translate to adding 1" in height. You will need more than 1" more height to maintain the original volume.

[seawalker]

A 1/2" on each side is 1" narrower I assume?

I would want to remodel it to see what the difference is. You would be affecting the region 500 to 600Hz down by as much as a db or so. So while it might not be drastic or a deal breaker it is definitely likely to be audible compared to a design done with the correct baffle dimensions. Altering the volume of the cabinet will further effect the low frequency performance. So if you are after a speaker that sounds like one of these designs your desired changes are working against that goal.

I kind of struggle to see why a cabinet 1" narrower and 1" taller would be aesthetically really much different. Also since the cabinet is a rectangle taking away 1" from the width won't translate to adding 1" in height. You will need more than 1" more height to maintain the original volume.

Yeah I realized after i posted that i made mistake in compensating with an inch - its not a perfect square- ..duh.. I know it doesnt seem like much but the Totem speakers are just a little bit slimmer by an inch and i personally like the look. but, modeling doesnt seeem like a task for a beginner

[dthomas]

Yeah I realized after i posted that i made mistake in compensating with an inch - its not a perfect square- ..duh.. I know it doesnt seem like much but the Totem speakers are just a little bit slimmer by an inch and i personally like the look. but, modeling doesnt seeem like a task for a beginner

Here is the issue above 2000Hz making the cabinet narrower won't have much affect on the diffraction if anything it might make it a bit better but since the crossover was optimized for the current baffle dimensions I would assume it has no effect. Below 2000Hz and especially below around 500 to 600Hz you can expect the response to drop by 1-2db. This will be audible as most of the energy in music will fall in the range of 20Hz to 2000Hz especially the fundamental frequencies of music. Also since these are already a small format midwoofer not sure I would make a change that is going to challenge the small midwoofer more.

No modeling is not a simple task for the uninitiated. My advice would be to stick to the baffle dimensions or find a project that suits you visually.

[jsr]

I'm with Don. The Continuum's in particular were designed and voiced for some pretty specific characteristics by a designer that really understands the details. It's always the builder's build, but in this case I think it's a mistake to alter the baffle. For this baffle, 1" is beyond the typical rule of thumb, and I don't think the rule of thumb applies when the design is so specific.

I didn't mean it wouldn't make an audible difference. I agree with Dave that it would make a difference when heard against an unmodified version, which is what I said. however, I don't think the difference would make the Continuums sound horrible...not optimal or the best they could be, but not horrible and may be something the OP wouldn't even notice since he wouldn't have a unmodified version to compare it to. There will be a dip due to the narrower baffle, but I still don't think that will make it bad, just not as good as it *could* be.
If the OP really likes the 1" narrower baffle, he can decide if a hit on performance (which I don't think would be a big one) is worth it for the aesthetics.

[fastbike1]

I'm still not there. The Continuums were designed to a specific performance vision and have been so universally praised that it just doesn't make sense to screw with the design. The OP is clearly more concerned w/ esthetics than sound and can get satisfying sound, slender boxes, and save some money by building OS MTMs or Nano Neo NTNs.
You're betting that it won't matter much, but you don't have any real basis other than a feeling. Given the detail of this specific design, seems like a poor bet.

I didn't mean it wouldn't make an audible difference. I agree with Dave that it would make a difference when heard against an unmodified version, which is what I said. however, I don't think the difference would make the Continuums sound horrible...not optimal or the best they could be, but not horrible and may be something the OP wouldn't even notice since he wouldn't have a unmodified version to compare it to. There will be a dip due to the narrower baffle, but I still don't think that will make it bad, just not as good as it *could* be.
If the OP really likes the 1" narrower baffle, he can decide if a hit on performance (which I don't think would be a big one) is worth it for the aesthetics.

[seawalker]

The OP is clearly more concerned w/ esthetics than sound and can get satisfying sound, slender boxes, and save some money by building OS MTMs or Nano Neo NTNs.

Sound is most important. I think the Continuums are a bad example. My reasoning was that many designers have there cabinet but state that it will also work in a parts express cab, which might be slightly different but still work. I took this to believe that I could then build a cab with my own "slight" difference in dimensions from the original. But, as members have stated, the designer has probably modeled for those other cabs, and I didnt know that. So Ill just stick to the plans for now.Good to hear a lot of praise for the continuums. That gets me more excited.

[fbov]

...I would suggest not changing anything if so you can hear the best results....

I'm with Don. The Continuum's in particular were designed and voiced for some pretty specific characteristics by a designer that ...

I'd absolutely leave Jeff Bagby's Continuum design alone. Jeff is so precise with his designs, any change will change what he intended, if subtly, or greatly.

Thanks to all for the insight. If I do the continuums I'll definitely leave them alone, ...Could I get away with 50 watts with the continuum's 83db is the question. Ideally I'd like more.

With all due respect, I think you all have really missed the boat here. This is still DIY, so why all the cast-in-concrete responses?

First, (to the OP) why not ask the designer? Jeff's a nice guy who'll give you a straight answer.

Second, are you folks aware of the vast range of Continuum builds out there? I've been to DIY's that have 3 of them! One looked like Jeff's, one was Jeff's, and the third was marble. There's even an MLTL design I believe. All sound very good, within reason...

Third, Jeff has published XO tweaks, necessary due to variation in RS28 tweeter sensitivity. Change was necessary to achieve what he intended!

Fourth, Jeff intentionally copied an old design, and did not include some of today's SOP's. Does that mean I can't roundover the edges? Bevel the edges? Make the sides of marble? Why not!!

To the OP, will 1" in 8 make an audible difference? YES! Will you hear it? Maybe...
Do what you can to preserve an 8" baffle width but realize that you do so as much to give the driver enough room to breath as it is to keep the XO cut-offs in line. Both affect sound quality. Better in all cases to trade height or depth to change internal volume. The real question is why do you want it narrower? Esthetics, or are you trying to fit into a space - a really bad idea for any speaker designed for free-standing use as this one is.

As to SPL capability, mine can't make 95dB in a 2400 cu ft room at my seat without bottoming, and I owe Jeff some data regarding it (at his request, btw) as he doesn't hear his bottoming and thinks I may have a problem (which I do, but that's another story).

Finally, lest you think I'm not a fan, my first DIY event, I gave Continuum top marks, as it and the Salk Songtowers were the only speakers that disappeared into their sound fields. When he did a limited release to the DIY community, I jumped at the chance. The sound they create is just wonderful for stereo listening. Just don't ask me for the plans, I'll only point you to the Meniscus kit.

Have fun,
Frank

[WernerM]

With all due respect, I think you all have really missed the boat here. This is still DIY, so why all the cast-in-concrete responses?

First, (to the OP) why not ask the designer? Jeff's a nice guy who'll give you a straight answer.

Second, are you folks aware of the vast range of Continuum builds out there? I've been to DIY's that have 3 of them! One looked like Jeff's, one was Jeff's, and the third was marble. There's even an MLTL design I believe. All sound very good, within reason...

Third, Jeff has published XO tweaks, necessary due to variation in RS28 tweeter sensitivity. Change was necessary to achieve what he intended!

Fourth, Jeff intentionally copied an old design, and did not include some of today's SOP's. Does that mean I can't roundover the edges? Bevel the edges? Make the sides of marble? Why not!!

To the OP, will 1" in 8 make an audible difference? YES! Will you hear it? Maybe...
Do what you can to preserve an 8" baffle width but realize that you do so as much to give the driver enough room to breath as it is to keep the XO cut-offs in line. Both affect sound quality. Better in all cases to trade height or depth to change internal volume. The real question is why do you want it narrower? Esthetics, or are you trying to fit into a space - a really bad idea for any speaker designed for free-standing use as this one is.

As to SPL capability, mine can't make 95dB in a 2400 cu ft room at my seat without bottoming, and I owe Jeff some data regarding it (at his request, btw) as he doesn't hear his bottoming and thinks I may have a problem (which I do, but that's another story).

Finally, lest you think I'm not a fan, my first DIY event, I gave Continuum top marks, as it and the Salk Songtowers were the only speakers that disappeared into their sound fields. When he did a limited release to the DIY community, I jumped at the chance. The sound they create is just wonderful for stereo listening. Just don't ask me for the plans, I'll only point you to the Meniscus kit.

Have fun,
Frank

Agreed,
I was trying to make the point that if these changes were made you would need to rework the crossover to try to best suit the drivers to the new baffle and enclosure. It is definitely possible. Will it sound as good as the original design? The only way to know that is to have both available for a comparison. it may not sound as good, but then again, it may not make much of a difference, or it may sound even better to the OP, as long as the changes have been accounted for, and made. It may even sound ok anyway, but until it is tried, it is speculation.

[jsr]

You're betting that it won't matter much, but you don't have any real basis other than a feeling. Given the detail of this specific design, seems like a poor bet.

I'm not arguing Jeff's attention to detail in the design and he did his best to make the design the best it could be. That being said, we're BOTH speculating whether it has an audible affect or not, especially to someone who would not be able to compare to an unmodified version. Neither of us have data to show the measurable impact on performance nor subjective data to say whether that measured difference is audible. While the design is optimized, optimized does not mean it will not work well slightly changed. I can optimize an engine to make 400bhp, but it doesn't mean it won't still make 390hp due to a slight change. To a race team, that 10hp will matter. To a weekend racer who does it for fun, less so. Optimization is typically to achieve that last bit of improvement. Non-optimized does not mean bad.
Again, we're both speculating, but that doesn't make my speculation any less relevant. And there's still the audible or not issue that's very person dependent as others have mentioned.

To the OP: Whatever design you choose to go with, don't be scared to experiment. Many of the great designs made by members here bend some hard and fast rules of thumb while still providing them enjoyment and satisfaction. Sometimes we get too stuck on how to make something as perfect as possible and forgot to just enjoy it (and that we can enjoy things that are less than perfect).

[fbov]

...To the OP: Whatever design you choose to go with, don't be scared to experiment...

+1

A narrower box has two performance issues. It's is narrower outside (affecting XO baffle compensation) and a bit tighter inside (affecting woofer interaction with the box cavity). As long as you deal with the latter in your narrow design, 1/2" panels clamped to the side, flush to the front, will give you the ability to hear the difference due to the former for yourself. If you like the sound wider, adding permanent panels will only deaden the box further, never a bad thing.

HAve fun,
Frank