Frugel-Horn Mk3 Builds & Build Questions - Page 69 - 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 20th August 2012, 04:42 PM   #681
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by pjblakey View Post
I have planed the oak, cut, assembled and sanded the first of my FHs - the second will be finished similarly this week.
The CHP-70s have been playing 10 hours+ a day for a week in some lashed up BR boxes. I transferred one of the drivers to a folded Tabaq that I finished last month, and, with it playing the left channel, and the FH the right, I had a quiet session while indulging in a bottle of merlot.
The only known construction deficiency in the FH is a lack of felt lining behind the driver.
- do you mean deficient in the design, or your particular build? I'm certain that Dave's full documentation goes into lengthy description and graphics outlining the areas surrounding and "above" the driver in which damping is most critical.

Ah yes, what doesn't go well with a nice merlot - sometimes you're just not in the mood for spirits.

Quote:
I live very close to the carpet capital of the world, but unable to find felt locally, except under the carpet of my F-150. I used some polyester batting instead, recognizing that it wouldn't perform the required duty, but maybe better than nothing.
A product that I particularly like working with is 1/2" Ultratouch which is composed of felted recycled denim fibres with a bonded fabric backer, but a jute or compressed cotton based upholstery material should work well enough.

Quote:
My room is such that the left speaker is 3 feet from the side wall, and the right speaker 6 feet from its' side wall. Both baffles are 2 - 3 feet from the front wall.
There seemed to be quite a disparity in the bass performance of the Tabaq(in the corner) to the FH on the right.
So, this morning, I got my Radio Shack SPL meter out and ran through the Stereophile test CD2 warble tones.
Using the C scale, I set my reference level(6ft from the speaker) to 60db at 200Hz(the first tone in the bass seqence) and determined the following:
In the corner(left), the Tabaq sound pressure level was +/- 3db from 200Hz to 40Hz(63db), whereas the FH suffered a bump between 100Hz and 50Hz peaking at 74db(80Hz) dipped to 61db at 50Hz and finished 63db at 40Hz. Nothing audible below 40Hz.
Comparing each speaker in the right channel(non-corner) location, they performed within 2db of each other, albeit, with much reduced low bass output(53db@40Hz).
This is the first horn type enclosure I have built - since both the Tabaq and the FH apparently benefited(?) from room corner loading, is there something peculiar about the FH that would cause the bump in the 50-100Hz octave when in the corner, or possibly lack of felt damping?
What I don't think Scott fully explained in his last post is that the design brief for the FH3 was to include compliance with a range of wide-band drivers in the size class of 3-4". Due to the varied T/S parameters and native FR among them, the degree of internal damping below the driver, as well as dependence on boundary loading will vary.

Quote:


Completing the warble tone tests, both speakers played within 2db all the way up to 10kHz(limit of my hearing).
Looking forward to completing the other - thanks guys for a beautiful design.
Peter
__________________
now on sabbatical
  Reply With Quote
Old 20th August 2012, 04:54 PM   #682
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
I believe he means that he hasn't been able to find the requisite felt damping yet.

Either way, it's going to need more than that in that channel to attenuate the additional unwanted gain. That's fine, I did design them with more gain than strictly needed with the MA units on the principle that you can always get rid of something you have too much of, whereas it's rather harder to increase what didn't exist in the first place.

Apologies, yes, when designing FH3, the object was for a box that would be tolerant of a wide range of drivers, so requirements for boundary loading as far as LF gain goes varies depending on the unit selected.

I prefer cabernet myself. Or a nice Sicillian syrah.
  Reply With Quote
Old 20th August 2012, 05:54 PM   #683
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by Scottmoose View Post
I believe he means that he hasn't been able to find the requisite felt damping yet.
I was just concerned that he, or other builders, might have skimmed too quickly through the voluminous FH document, and missed these specific details
Quote:
I prefer cabernet myself. Or a nice Sicillian syrah.
I've yet to find an Argentinian or Chilean red that I didn't like - malbecs, syrahs, cabs and savs - and where we're located, for as little as $10 (Everything Wine - over 3000 brands in stock - eventually we might try them all)
__________________
now on sabbatical
  Reply With Quote
Old 20th August 2012, 07:26 PM   #684
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Such a trial, having to work through 3,000 brands.

Unfortunately the olympics have shamed me into doing something about my lousy health, and I need to drop about 2 stone to get where I want to be, so I'm currently on the wagon.

Last edited by Scottmoose; 20th August 2012 at 07:35 PM.
  Reply With Quote
Old 20th August 2012, 08:30 PM   #685
diyAudio Member
 
Join Date: Mar 2009
Location: Smoky Mountains, NC
Thanks for all the comments.
Scottmoose is correct - deficiency in my build by not having felt damping...yet.
I initially connected the FH with no damping whatsoever below the driver, and there was considerable "plumminess" to the bass, so I added some poly fill and the result was much better. Great sounding speaker - may sell my Apogees!
Peter
  Reply With Quote
Old 20th August 2012, 09:18 PM   #686
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
Quote:
Originally Posted by Scottmoose View Post
Such a trial, having to work through 3,000 brands.

Unfortunately the olympics have shamed me into doing something about my lousy health, and I need to drop about 2 stone to get where I want to be, so I'm currently on the wagon.

so you just jog to & from the local wine shop and cut back on the fish & chips
__________________
now on sabbatical
  Reply With Quote
Old 22nd August 2012, 03:21 AM   #687
diyAudio Member
 
Join Date: Jul 2005
Location: Aotearoa
Finished my FHs a week back so thought I would report on my listening impressions.

I won’t bother with any pics, looks like many other pairs that have been made! Built with 18mm high grade (and expensive) ply, just one slight derivation from plans to accommodate my lack of tools/skills. Straight forward clamp and glue construction.

Managed to find some ˝” cotton/wool felt by ripping out some carpet underlay, for other stuffing I used a wool based insulation product I have used in the past on multiple builds including BIBs.

Stating the obvious, my impressions are as much about the driver, Alpair 7, as the FH. Driving with a Tripath TK2050 amp (41hz Amp11 much modified) and Squeezebox Touch (FLAC files) so not top end equipment tho quite capable.

The HF extension and clarity of the drivers is very impressive, the overall sound is clean, dynamic and punchy with great integration of the bass extension. OK, so there is bass missing (as compared to my FE208EZ BIB speakers which is somewhat unfair) but the bass is very clean and has good impact. They are exciting to listen to and exceed what I was expecting from a speaker system at that price. Not sure how loud they will go (scared off a little at seeing a warped Alpair cone in another thread) but listening to a favorite CD yesterday at a level that was very satisfying, full on powerful sound. They look cool too, very happy with the outcome.

Thanks to the designers for making this project public.
  Reply With Quote
Old 23rd August 2012, 09:47 PM   #688
diyAudio Member
 
Join Date: Mar 2009
Location: Smoky Mountains, NC
Second FH functionally complete and the pair are playing beautiful music. This must be the biggest bargain of my musical life(and that going back to the '60s mono LP days).
The speaker close to the corner of the room still sounds a little "plummy"in the bass. I put about 20g of polyfil behind the baffle of that speaker - maybe a little more is required? Waiting for the felt to arrive - I assume that will not affect the bass region though. I'll do some more testing when fully complete - in the meantime, just enjoying the music.
  Reply With Quote
Old 23rd August 2012, 10:12 PM   #689
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Yes, it'll likely need some additional damping if there's still too much LF output on that channel. Beauty of DIY -you can adjust this yourself to suit the environment, unlike with commercial gear, where you're largely stuck with it.

Glad you like them.
  Reply With Quote
Old 24th August 2012, 05:28 AM   #690
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
I ship 40 g of Acousta Stuff with each flat-pak speaker for the damping below the driver (and 30 g for the pointy end of the wedge)

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  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
Frugel-Horn Mk3 planet10 Full Range 1371 Today 10:12 AM
Frugel-Horn Mk3 flat-paks planet10 Planet 10 hifi 462 3rd July 2014 01:56 AM
Frugel-Horn Mk3 Auditions planet10 Full Range 24 8th June 2012 08:18 PM
"straight" frugel horn mk3 mahleriana Full Range 10 15th April 2011 02:28 AM
My Frugel-Horn Build italynstylion Full Range 130 22nd June 2010 01:24 AM


New To Site? Need Help?

All times are GMT. The time now is 06:24 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