Visaton B200 / Alpha 15a - What design?? - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 30th March 2010, 10:56 PM   #1
diyAudio Member
 
aquapiranha's Avatar
 
Join Date: Jul 2007
Default Visaton B200 / Alpha 15a - What design??

Hi Chaps! I have built a a set of OB's using a B200 and 2 X Alpha 15's per side, but I cannot no matter what I try get any decent amount of bass from the system! Don't get me wrong, I am not expecting subterranean earth shaking bass, just something musical, and visceral.

I am currently using the system active via a Rane AC22B X-over, and the bass drivers are wired in series (I did try them for a while in parallel, but the load seemed too great and there was hardly any bass...) and powered using a Sure 4 X 100W board ( I have tried others including a hefty hypex unit)

So, what am I asking/. well, I am hoping someone can come up with an alternative design, presumably with the B200 in OB, maybe the Alphas in another arrangement? I am not limited by WAF, just by cost, so cheap and cheerful!.

The option I have seriously considered is using the B200 alone, in an OB and going back to passive with maybe a small tripath (trends for eg.) or valve amp. If this can be done while providing at least a modicum of musical bass I will be happy.

I know that is a lot to ask, but any ideas / experiences would be very gratefully appreciated. Many, many thanks in advance, Steve.


Click the image to open in full size.

Last edited by aquapiranha; 30th March 2010 at 10:58 PM.
  Reply With Quote
Old 30th March 2010, 11:59 PM   #2
diyAudio Member
 
Join Date: Jan 2007
Hi Aquapiranha,

If you're not getting monster bass, I would suspect a phase / wiring issue. After that, a room issue. After that, maybe the baffle is just too narrow for the bass you're expecting?

I have the same Rane xover and the B200. I'm wondering:

(a) how low do you get (have you tried test tones maybe?)

(b) what xover point are you using on the Rane?

(c) how are you going into the Rane's XLR? Does your pre have XLR out or, if RCA, are you using level/impedance matching box?

(d) Have you read this MJK article? The setup is similar (4 Alpha's, active crossover): Project 7 : Lowther Open Baffle System Design Project
  Reply With Quote
Old 31st March 2010, 05:50 AM   #3
diyAudio Member
 
aquapiranha's Avatar
 
Join Date: Jul 2007
Quote:
Originally Posted by rjbond3rd View Post
Hi Aquapiranha,

If you're not getting monster bass, I would suspect a phase / wiring issue. After that, a room issue. After that, maybe the baffle is just too narrow for the bass you're expecting?

I have the same Rane xover and the B200. I'm wondering:

(a) how low do you get (have you tried test tones maybe?)

(b) what xover point are you using on the Rane?

(c) how are you going into the Rane's XLR? Does your pre have XLR out or, if RCA, are you using level/impedance matching box?

(d) Have you read this MJK article? The setup is similar (4 Alpha's, active crossover): Project 7 : Lowther Open Baffle System Design Project
Hi RJ, many thanks for the response. Out of interest, can you describe your set up in more detail?

I have not tried test tones, but suffice to say I was getting a lot lower in the same room with a Sachiko and FE206E.

I am using adapters with the Rane, and I appreciate that this means a loss of 6 db, but that is treble as well as bass.

MJK very kindly assisted me with the design, and advised me on the sizeof the baffle, I will try to find the mail.

I have read the article, but I am not very au fait with the theory to be honest.

does anyone recommend using a different set up for the bass? maybe a H frame or similar, maybe a box?

Thanks, Steve

Last edited by aquapiranha; 31st March 2010 at 05:59 AM.
  Reply With Quote
Old 31st March 2010, 06:15 AM   #4
ra7 is offline ra7  United States
diyAudio Member
 
Join Date: Feb 2009
Blog Entries: 1
You should have earth shaking bass with those woofers... well, you certainly should have bass. Check your crossovers and whether you have them configured them incorrectly.

I had a similar thing going on for a while, with a single 15A per side and it turns out I had some errors in the crossovers. Even with one per side, there is enough bass to wake the neighbors.
  Reply With Quote
Old 31st March 2010, 11:20 AM   #5
diyAudio Member
 
aquapiranha's Avatar
 
Join Date: Jul 2007
Quote:
Originally Posted by ra7 View Post
You should have earth shaking bass with those woofers... well, you certainly should have bass. Check your crossovers and whether you have them configured them incorrectly.

I had a similar thing going on for a while, with a single 15A per side and it turns out I had some errors in the crossovers. Even with one per side, there is enough bass to wake the neighbors.
Yes you are correct. I do not even want massive bass, just something tangible and real. I have been thinking and now I think I will look at the x-over. It is set up correctly, but I have a suspicion it might not be doing its job properly?

I need to finish my LDR so that I can run the signal directly into the bass bypassing the rane, who knows? maybe the rane is u/s?

any other ideas would be great, or anyone selling a dbx driverack pro for peanuts....?
  Reply With Quote
Old 31st March 2010, 01:04 PM   #6
Vix is offline Vix  Yugoslavia
diyAudio Member
 
Vix's Avatar
 
Join Date: Nov 2003
Location: Somewhere on Planet Earth
Try these crossover points:

Alphas: 120 Hz 12/db oct. L-R
B200: 300 Hz 12 db/oct. L-R

Alphas better be wired in parallel. Make sure yuu try it with another, capable SS amp, as it can make big difference.

Also, For Visaton you may want to try a 0.68-1 Mh inductor with 6.8-10 Ohm/ 10-20 w resistor (try different values to suit your taste) in series with a positive lead, between a speaker and the amp.

It can be a bit painful and time consuming until you hit the right combination, but it's worth it.
  Reply With Quote
Old 31st March 2010, 02:52 PM   #7
SAC is offline SAC  United Kingdom
diyAudio Member
 
Join Date: Feb 2007
Location: London
On the multiway Systems Pictures and Descriptions thread, you can see my system on Post 1763. It is very similar to yours, and even moving the crossover up to 5khz instead of 1.2khz, reducing the treble hump, made great improvements to perceived bass.

The rising response top end of the B200 is far more sensitive than the bass from the alphas. I do not know if you have done anything about this but the system is commonly held to be unlistenable until this is dealt with, and the volume will be unbearable before the bass gets going.

As a test, if you turn up the volume with the B200 disconnected, can you get satisfactory bass that way? If so, then it is just a matter of balancing out the sensitivities of the B200s and the alphas.

Ditto to getting those alphas in parallel (4ohms) versus series (16ohms).
  Reply With Quote
Old 31st March 2010, 03:33 PM   #8
ra7 is offline ra7  United States
diyAudio Member
 
Join Date: Feb 2009
Blog Entries: 1
Yes, being able to turn the volume down on the b200 is important as you want to make up for the ob loss in bass. What is happening is you're trying to match the efficiency of the full range to that of the woofer down low. This means you'll need more power.

Ditto about a good ss amp.
  Reply With Quote
Old 31st March 2010, 04:30 PM   #9
diyAudio Member
 
aquapiranha's Avatar
 
Join Date: Jul 2007
Thanks guys. I have tried adjusting the crossover point on the rane, as well as the gain of the treble against the bass, and this made no difference other than to dull the sound. With the gain for the b200 on 2/3, and the alphas on full, there is still hardly any bass output. I have tried changing from parallel to series and this made little difference either. I did not want to go down the route of messing about with a passive crossover, hence me using the rane.

Hmm.... I need to have a good think. I have seen people with a similar set up saying that the impact and bass they get is incredible, so there must something seriously awry here I think.

Steve
  Reply With Quote
Old 31st March 2010, 04:35 PM   #10
ra7 is offline ra7  United States
diyAudio Member
 
Join Date: Feb 2009
Blog Entries: 1
How much power are you outputing to the woofers? Which amps are you using?
  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
F/S Alpha 15a nvrgdenuf Swap Meet 6 9th July 2009 12:20 AM
OB 2-way Alpha 15A with 27TDFC? etc grantnsw Multi-Way 12 10th June 2009 06:01 PM
F/S (2) Alpha 15a nvrgdenuf Swap Meet 0 25th May 2009 06:30 PM
my fe167e and alpha 15a combo and ? AudioGeek Full Range 1 21st September 2008 01:09 PM
Visaton B200 in Alpha TL Andrewbee Full Range 15 15th July 2005 04:04 PM


New To Site? Need Help?

All times are GMT. The time now is 01:59 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