Tempest on its way - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 1st January 2005, 11:28 AM   #1
diyAudio Member
 
Join Date: Jan 2005
Location: boomboom land
Send a message via AIM to CBFryman
Default Tempest on its way

Aloha!

This is my first post here in DIYaudio. First I'd Like to intoduce myself and then Ill get on to my question.

My name is Chris Fryman, i am 16 and live in north Florida. I have a passion for loud music, especially ear shadering distorted guitar solo's and ground pounding bass. However, I also enjoy listening to my music at a reaonable level with lifel ike sound quality. I have helped out around a local audioshop and have aquired a large portion of my audio knowledge from simply scaning through forms such as this one and other internet DIY's.
Besides Audio i also enjoy cars, european and asian imports mostly. I also enjoy surfing and Wakebording.

Well now that you know half my life's story here goes my question.

My Current Situation Home Stereo Wise:
2 Audiobahn AW10's in a 3.2cuft Enclosure Tuned to 32Hz with 192w RMS and ~250 Maximum. Yes, i know. Audiobahn is **** and should never be used in home audio. but i was desperate. I am particularly pround of the enclosure. except for i got through the building but was to excited to finish painting.
Well these are now for sale.

What i am soon to have.

I have an Adire Audio Tempest on the way. as soon as i get the Bahns sold i will be buying the materials to build the enclosure. My question is for the enclosure and later pretaining to the amp.

I am thinking of trying my first down fireing subwoofer. The tempest is suited for this i know. but my question is will any output be lost because of this? I am looking for maximum output with what i have. my enclosure plans are 4-5cuft (still drawing them up trying to get the strongest enclosure possible while giving the tempest maximum volume with the aloted space i have) tuned to 18.8 or 20Hz.

Now if i am not satisfied with the output on the 192w i have now (the amp is a POS anyway and upon idleing has a 60Hz buzz. i get tired of it because the louder i have the amp turned up the more prevelant the buzz is. i am thinking of chucking it anyway) i am probably going to spring for an Adire AVA250. Problem. I want 270w@4ohm but the tempest is dual 4ohm coils. So... Is it safe to run 270w into a single coil. From all of the installs i have dont i have used both coils because of thermal power reasons. of corse most of the installs i have done are car audio where 1 and 2ohm loads are not uncommon. Because the tempest is rated to 400w per coil (i beleive) i know 270w wont harm it thermaly but can it harm it in any other way or hinder its efficency because of this? Once i save up eough money and im still not satisfied with 270w i will buy another AVA250 and have 540w cranking this 15" beast. but that is far into the future (not that it takes 540w to bottom out the suspension on this very fine woofer)

Cliff Notes:
I would say read the post but hey, its my first and im not accustom to this forum so ill be nice untill i find my place. lol.

Will Making a down fireing woofer enclosure hinder its performance in anyway compared to the exact same enclosure with a horizontaly mounted woofer?

Because the tempest's coils can handle near 400w each 270w isnt going to harm one thermaly. but will running only one coil to get maximum eficency out of an AVA250 bring any problems or hinder performance in any way?

Oh, this wasnt stated above but. I was thinking of trying a passive radiator set up as well. I would really need help on this one because in all of my experence with car audio ive never used a passive radiator and have no idea how to tune them or how to design an enclosrue for them. So what would be a good size and what type set up would be best if i where to go passive radiator (ie. 15" or 18" passive radiator. How do you go about tuning a passive radiator, and what sort of set up, down fireing driver horizontaly fireing radiator or down firing driver up fireing radiator?)
  Reply With Quote
Old 1st January 2005, 04:27 PM   #2
herm is offline herm  United States
diyAudio Member
 
Join Date: Mar 2002
Location: Pasadena, CA USA
I'll help on one of the questions:

Go to http://www.adireaudio.com/

Click on technical, then app notes.
There is a paper on passive radiator designs.

-herm

P.S. Welcome to diyAudio!
  Reply With Quote
Old 2nd January 2005, 12:45 AM   #3
diyAudio Member
 
Join Date: Apr 2004
Location: Costa Rica
Send a message via AIM to johninCR Send a message via MSN to johninCR Send a message via Yahoo to johninCR
Horizontal mounting does decrease max SPL because gravity uses up some of its Xmax.

PR's must be vertically mounted.

I don't think that's the amp you want. You are looking for max performance, so you need to match the driver's capacity plus extra for head room. You want to avoid amplifier clipping at high levels. It's bad for your drivers and your ears regardless of power rating.

I don't think it's a good idea to plan on 2 amps for one driver since you want an identical signal going to both voice coils.

One amp on one voice coil is advantageous since you can use RDO operation with a variable resistor accross the other voice coil and end up with a sub that has adjustable sound. Check Adires Tech paper under Resistively Damped Operation for more info. You do, however, give up 3db of max output using only 1 voice coil.

Something to consider when coming up with a cabinet design that you want to push to the driver's limits is cone excursion. Just because a driver is rated for 400 watts per VC doesn't mean that it can handle that power in the lowest frequencies. A lot will depend upon the tuning of your enclosure.
__________________
Everyone has a photographic memory. It's just that most are out of film.
  Reply With Quote
Old 2nd January 2005, 01:25 AM   #4
diyAudio Member
 
Join Date: Jan 2005
Location: boomboom land
Send a message via AIM to CBFryman
Quote:
Originally posted by johninCR
Horizontal mounting does decrease max SPL because gravity uses up some of its Xmax.

PR's must be vertically mounted.

I don't think that's the amp you want. You are looking for max performance, so you need to match the driver's capacity plus extra for head room. You want to avoid amplifier clipping at high levels. It's bad for your drivers and your ears regardless of power rating.

I don't think it's a good idea to plan on 2 amps for one driver since you want an identical signal going to both voice coils.

One amp on one voice coil is advantageous since you can use RDO operation with a variable resistor accross the other voice coil and end up with a sub that has adjustable sound. Check Adires Tech paper under Resistively Damped Operation for more info. You do, however, give up 3db of max output using only 1 voice coil.

Something to consider when coming up with a cabinet design that you want to push to the driver's limits is cone excursion. Just because a driver is rated for 400 watts per VC doesn't mean that it can handle that power in the lowest frequencies. A lot will depend upon the tuning of your enclosure.
Thanks For the input.

Do you have any amp reccomendations. Ive heard great things about the AVA250 asfar as quality and price issue. It is right around $170 and that is for a full Subwoofer plate amplifier. Yes 270w isnt alot, but it doest take alot to reach suspension limits of the tempest. Since most bass amplifiers can run as much as 400+ USD and im only a teenager working on a limited budget. Any input will be greatly appreciated.

Ive done 2 installs with the tempest bot in cars. the first (my mistake run) was in a 4cuft enclosure tuned to 25Hz. The tuning was way to high for that driver and i used an eD Six.2 giving it way more power than needed. reguarless to day the suspension bottomed out at 25Hz with only 412w. All this and it doesnt even use and XBL^2 Motor.

Also. What port area do you reccomend to get optimal velocity near tuning frequincy (18-20Hz area most likely)?
  Reply With Quote
Old 2nd January 2005, 02:09 AM   #5
diyAudio Member
 
Join Date: Apr 2004
Location: Costa Rica
Send a message via AIM to johninCR Send a message via MSN to johninCR Send a message via Yahoo to johninCR
A cheap amp solution is a car amp plus a 12 volt regulated power supply. Be sure to get plenty of amps on the transformer, so you don't melt it down. A class D amp will be much more efficient and won't need as much amperage or generate as much heat. You can get enough power and the ability to power up both VC's in parallel for the same price. There are lots of junk plate amps out there and it sounds like you know car audio already anyway to pick a good one, so your money will go much further. I wouldn't put it in the cab due to heat issues.
__________________
Everyone has a photographic memory. It's just that most are out of film.
  Reply With Quote
Old 2nd January 2005, 03:16 AM   #6
diyAudio Member
 
Join Date: Jan 2005
Location: boomboom land
Send a message via AIM to CBFryman
I was full of misinformation. After checking the wrap sheet on the tempest agian responding to the thread Coil Woes i found that the tempest is dual 8ohm coils. This will allow me to wire them in a parrallel configuration to acheive a 4ohm impeadence rendering 270w from the AVA250.
As far as the car amp idea. that is my current set up. Rememer i mentioned the 60Hz buzz. well i have a crappy power supply. on top of a crappy sony amp. The powersupply can only supply enough amps for the sony amp to make 192w into a 2ohm load on top of the buzz. It is a 25a supply. I can get another for 40 USD and wire them parallel. 50a into an efficent class D amp into a 4ohm load (not that class D would be much more efficent than A/B because of the higher load) i may be bale to pull 350-400w. im not sure of a cheaper highquality amp that will make that sort of wattage into a 4ohm load.

My other idea now that i have been corrected on the impeadence of the Tempest. Can Plate amplifiers such as the AVA250 be wired like Class D's. Master and Slave? If so Will they keep their 4ohm stability?
  Reply With Quote
Old 2nd January 2005, 03:50 AM   #7
diyAudio Member
 
Join Date: Oct 2004
Location: t-dot, canada
Send a message via MSN to xstephanx
im not sure how well this woul work, but could you not just build a big step down inverter? we made some in science that only operated with batteries but im sure you could make a bigger one with heavier guage wiring and a case/cooling fan(s) quite easily. then you would have lots of power to power a car amp by just lowering the voltage coming out of your wall outlet to something the amp can handle and plugging it all together. Im probably just babbling away and this very well COULD fry your amp and waste your money so **DO NOT TAKE MY WOR FOR IT***
  Reply With Quote
Old 2nd January 2005, 04:02 AM   #8
diyAudio Member
 
Join Date: Jan 2005
Location: boomboom land
Send a message via AIM to CBFryman
Getting the voltage down to 12v isnt the problem. its turning it from 60Hz to DC voltage that is the hard thing.
  Reply With Quote
Old 2nd January 2005, 04:23 AM   #9
simon5 is offline simon5  Canada
diyAudio Member
 
Join Date: Nov 2004
Location: Québec, Québec
A plate amplifier like the AVA250 is very good.

But, if you don't need all the features, why you don't consider something like a Rythmik Audio 350, capable of 380W RMS into a 4 ohms load, for only 159$.

I bought a Rythmik Audio 250 for a Shiva, and I'm satisfied, probably this higher end model could satisfy you.
__________________
DIYaudio for President !
  Reply With Quote
Old 2nd January 2005, 04:26 AM   #10
diyAudio Member
 
Join Date: Oct 2004
Location: t-dot, canada
Send a message via MSN to xstephanx
i knew i overlooked something...

If you wanna take advantage of the exchange rate creativesound* has their 360/250 watt plate amp(360 into 4 ohms) for cheap as well.


*www.creativesound.ca
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: Tempest X dshambala Swap Meet 1 26th April 2009 03:17 PM
Tempest help Robertburchell Subwoofers 9 25th July 2006 06:56 PM
My Tempest badman Subwoofers 8 4th March 2006 02:56 PM
My Tempest with the New AR.diy (pic) MCH Multi-Way 0 31st March 2003 02:34 AM
Tempest Sub itzvic Subwoofers 5 25th February 2002 09:54 AM


New To Site? Need Help?

All times are GMT. The time now is 04:18 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2