beginning a SONOTUBE sub build - want some advice

[Txgrizzly]

Ok I have decided to build a new sub for my HT and have started looking at Drivers and AMPS in my price range. What do you guys think of this Driver and amp combo?

Dayton RSS390HF-4 15” driver
BASH 500w digital subwoofer plate amp


Can you suggest a possible better combo around the same price range or are there any deals that someone knows about right now?

Also there isnt any real crossover materials is there since the amp does all that right?
I am looking at getting a 18" dia sonotube or should i go with an 21" with a 15" driver?

I know, newbee questions, but hey i am a newbee...

Thanks guys.. :T

[JonP]

Choice of diameter isn't really critical, sound wise. It will determine the look and size... if you want a shorter, wider one go with the wider diameter, if a longer thinner one might be better, say you want to lay it down in back of a room or something, go with that...

Important stuff is modeling the tuning well. Find Unibox, or WinISD, or Jeff Bagby's Woofer and Box Designer... Another handy tool, (and site) is Bob Collo's subwoofer site. He has a nice, free, sonosub enclosure calculator that is very handy.

Sorry about lack of links... should have been sleeping 1/2 hr ago... :Z

[Txgrizzly]

ok i loaded the driver into WinISD and it came back with:
Volume = 11.367 ft3 (could i adjust this to 11.5 ft3 without problems?)
Tuning freq = 17.37
vent = 4.02 dia 6.95 length (would i be able to change this to 4" dia and 7" long without problems?)
the gain is at -2db at 17.5 hz and then flat at 0db the rest of the way, i tried loading the diagram but it said the file size was to large even after i made it so small that you couldnt read it.

so my next question is with the volume of 11.367 i should be able to just load that info into one of the sonotub calculators and that should spit out a diameter and length of tube i need right?

[Txgrizzly]

well dang, i just put the driver info into this designer software (http://www.subwoofer-builder.com/sonosub.htm) and it says this driver sags to much to be mounted horizontally. i will either have to lay the tube on its side or build a cube or look at a different driver... i would really like to have the tube standing up so i guess i go back and look at some other drivers...

[ThomasW]

Correct, a better choice from PE is the Titanic 15".

IMO it would be a good idea to go with 20" dia tube instead of the 18" stuff. That way the driver has a bit more room to 'breath'.

[Txgrizzly]

thanks again thomas...

new questions for everyone now...
1. will the 500watt BASH amp drive that speaker ok?
2. also does a sonotub need internal bracing or liners?
3. i have heard alot of people talk about putting a "feedback distroyer" on a sub to clean up the freq band. is this worth it and is it complicated to wire it in and setup?

[Amphiprion]

1)Yes
2)No
3)Yes,no,maybe

[Dennis H]

The Dayton RS series has far less distortion than the Titanic. I haven't checked it for acceptable sag pointing down but the HO version only has about 2/3 the sag of the HF version -- way stiffer and somewhat heavier.

[Txgrizzly]

thanks Mark and Dennis... i put the HO version into the tube formula and it came back as acceptable. i also am looking at buying the feedback destroyer...
here is a BOM i am looking at buying from PE:

Gold Plated Banana 5-Way Speaker Terminal $3.49 $3.49
Precision Port 2" Flared Port Tube Kit $9.65 $19.30 (for another project)
Behringer DSP1124P Feedback Destroyer Pro w/Parametric EQ $99.99 $99.99
Sonic Barrier 1/2" Acoustic Foam w/PSA 18" x 24" (for a future project)
Sonic Barrier 1" Acoustic Foam w/PSA 18" x 24" (for future project)
Bash 500W Digital Subwoofer Amplifier $228.58 $228.58
Dayton RSS390HO-4 15" Reference HO Subwoofer 4 Ohm $159.80 $159.80

[Txgrizzly]

quick question?
should i line the inside of the tube with acoustic foam? i saw one build where it had it and another build didnt mention it...
thanks guys.

[ThomasW]

It's questionable how audible distortion is in the passband where subs operate. Nousaine uses 10% for his output testing and says that's inaudible.

The Titanic offers 20.5mm of Xmax vs the 12mm of the RSS390HO

[Txgrizzly]

thanks Thomas, i just dropped 6 bills at PE ordering up the parts for the Sub as well as some other parts...
I am going to go with the RSS390HO and the 500w Bash amp with the Feedback destroyer...i think i am officially addicted.
i also think i am going to build a ported .50 ft3 enclosure for my RS150MT i just built to see what the difference is in bass response is compared to my sealed enclosure....

[Hdale85]

When it comes to subs its all about displacement. A sub with 20mm of xmax is going to displace a lot more air then a sub with 12mm of xmax. The RSS390 is a nice driver don't get me wrong it's just hard to get into the really low end of the sound spectrum with it.

[Txgrizzly]

Dougie,
with that being said the RSS390 would be more of a musical sub than a HT sub correct? well i have already ordered the RSS390 and will see how it does in the Sonotub. if it doesnt go low enough for my system i will just buy the Titanic mkIII and build a musically enclined sub enclosure for my home office system with the RSS390...or i might just say screw it and spend the extra $50 and change my order since the RSS390 is backordered till the middle of this month...

When it comes to subs its all about displacement. A sub with 20mm of xmax is going to displace a lot more air then a sub with 12mm of xmax. The RSS390 is a nice driver don't get me wrong it's just hard to get into the really low end of the sound spectrum with it.

[Rick Craig]

One thing to keep in mind is that some drivers are suspension and / or motor-limited. In that case they may fall short of being able to reach their full x-max with reasonable linearity.

[Txgrizzly]

Rick,
do you know if the MKIII has this issue with the motor/suspension?

[Rick Craig]

Rick,
do you know if the MKIII has this issue with the motor/suspension?

I don't know (haven't seen any Klippel tests for the Titanic) but it should be fine. X-max is quoted often but it really won't tell you what the motor and suspension can do in terms of real-life performance.

[Txgrizzly]

Thanks Rick,

Well, i went ahead and changed my order to the Titanic mkIII and parts should be here this week. i am also going down to buy some 20" sonotube. it bits, i have to buy a 12' peice for a sub that i will only need about 5' of it. maybe i can find someone locally who wants me to build them a sub...