tuba ht rss390ho

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BryanT
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Re: tuba ht rss390ho

#31 Post by BryanT » Tue Aug 15, 2017 5:47 pm

Uhhh, what?

How does a wooden enclosure change the impedance of a subwoofer? I've honestly never heard or thought of anything like that. Changing "efficiency" I'll believe without question. "Impedance" has to do with voice coils, how would that change no matter the subwoofers environment? Sealed, ported, free air, horn, infinite baffle.....4ohm voice coil is going to be 4 ohm when you hook a multimeter up.

Please correct me if I'm wrong. That reply totally confuses me lol.

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Jason Stromberg
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Re: tuba ht rss390ho

#32 Post by Jason Stromberg » Tue Aug 15, 2017 6:08 pm


BryanT
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Re: tuba ht rss390ho

#33 Post by BryanT » Tue Aug 15, 2017 6:30 pm

Interesting...

"When I quote a T30 as having a 12 ohm impedance the actual measured impedance within the passband varies from about 10 ohms to 60 ohms; the 12 ohm figure is what you can count on as the average minimum load that the amp will see. Quoting the exact impedance is like asking 'how high are the Rocky Mountains'."

That part I always knew, that's how I assumed they came up with what the ohms for a speaker are. Instead of with mountains for "peaks" they use the lowest ohm. That way you don't try to run a 2 ohm subwoofer with a 4ohm amp. While the 2 ohm subwoofer doesn't always see 2ohms, that's the lowest number it sees. I'm thinking "nominal" has something to do with that.

Very interesting. Thanks for the link. I thought you were saying if you hooked up speaker wires of a subwoofer to a multimeter in a horn box it would read different then in a sealed or ported box...if no sound is going through it. I'm still a bit confused as to how that changes in an enclosure. So in theory a 4ohm subwoofer in a horn sees an average of 8 ohms? And in a sealed box it would/could see a different average?

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Radian
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Re: tuba ht rss390ho

#34 Post by Radian » Tue Aug 15, 2017 7:17 pm

DCR and impedance

If there's any confusion here, clarifiction lies in their definitions. They are not interchangeable terms for the sake of discussion, even though they're both expressed in Ohms.
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CoronaOperator
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Re: tuba ht rss390ho

#35 Post by CoronaOperator » Tue Aug 15, 2017 8:11 pm

BryanT wrote:Uhhh, what?

How does a wooden enclosure change the impedance of a subwoofer? I've honestly never heard or thought of anything like that. Changing "efficiency" I'll believe without question. "Impedance" has to do with voice coils, how would that change no matter the subwoofers environment? Sealed, ported, free air, horn, infinite baffle.....4ohm voice coil is going to be 4 ohm when you hook a multimeter up.

Please correct me if I'm wrong. That reply totally confuses me lol.

Different boxes limit the travel of the cone at certain frequencies. Example, in a ported box, the cone has minimum local travel at the box's tuning frequency. Since that voice coil is in a magnetic field the reduced travel will lower the impedance.
Built:
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2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

BryanT
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Re: tuba ht rss390ho

#36 Post by BryanT » Wed Aug 16, 2017 12:27 pm

Weird and interesting, never thought about that.

Back to the 24 vs 36...are alot of people running the 24 more then the 36?

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Jason Stromberg
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Re: tuba ht rss390ho

#37 Post by Jason Stromberg » Wed Aug 16, 2017 1:30 pm

24" wide cabinet makes the best use of a 4' x 8' sheet of plywood.

BryanT
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Re: tuba ht rss390ho

#38 Post by BryanT » Fri Aug 18, 2017 4:34 pm

So yea I think the inuke1000dsp only does 210 rms at 4 ohm.

The issue is I want dsp. I want to build something that I don't want to sell and upgrade. Can the inuke3000dsp work? I think you can limit power from what I've read. So limit it to 400 or 500 watts? I like the idea of having an amp I can add a second subwoofer too.

I was pretty pleased with what I had, so if the 24" tuba ht is better then it's an easy pick.

CoronaOperator
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Re: tuba ht rss390ho

#39 Post by CoronaOperator » Fri Aug 18, 2017 6:33 pm

One thing about the inukes for home theater is that it has a pretty loud fan. They can be upgraded to quieter ones, google inuke fan upgrade.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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DJPhatman
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Re: tuba ht rss390ho

#40 Post by DJPhatman » Sat Aug 19, 2017 1:46 pm

BryanT, search YouTube for "BFM THT". There are some really good video/audio examples of what a THT can do with very little power.
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BryanT
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Re: tuba ht rss390ho

#41 Post by BryanT » Mon Aug 28, 2017 7:38 pm

So, my subwoofer sold and I bought box plans. Haven't started the build yet but I plan to go with one of these. I'm guessing the bash 300s is what I should plan to buy?

What are other 15" tuba ht guys running for drivers and amps?

BryanT
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Re: tuba ht rss390ho

#42 Post by BryanT » Tue Aug 29, 2017 6:35 am

Well shoot. Now I'm considering a lilwrecker build. I have the room, it's tuned lower to 17hz, driver access is easier.....I think the box is easier to build too.

To many options lol.

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