I hate speakers...
Printed From: Graham Slee Hifi System Components
Category: And the rest
Forum Name: Transducers, Speakers, Mics...
Forum Description: Interested in bi-amping, tri-amping, crossovers, speaker design, miking techniques, EQ - the list goes on
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=1135
Printed Date: 18 Apr 2024 at 5:49pm
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: I hate speakers...
Posted By: Graham Slee
Subject: I hate speakers...
Date Posted: 14 Jul 2011 at 9:02pm
It has now taken 7 months to find a position the "award winning" Usher 520s will work in. Excuse the mess... this is after all a hard working workshop and is more of a tip because of messing around with speaker placement. These Ushers have been just about everywhere in here, rerouting cables on a weekly basis and lugging things like filing cabinets around to try and please them. So do I find these Usher's particularly difficult? Well, I suppose not really. It's been nearly 40 years since I started finding just how awkward speaker positioning can really be. The thing is, until you get the speakers in their correct position you simply won't know how good or bad the rest of your system is. Now, for me that's crucial, and why I've spent 7 months on and off just on these speakers. Placement wasn't the only problem. I just can't understand how these speakers gained any award? These are ex-dem so were fully burnt-in but sounded highly distorted for the first few weeks, until that is I got rid of those horrible audiovile wound (read highly inductive) caps in the crossovers, replacing them with stacked film types. Don't blame the amps - they can drive just about anything. Even that wasn't enough. The 520s are ported and in the past, ported (or reflex) speakers were never stuffed full of wadding, so what's changed? I reckoned nothing, so I pulled out all but the bits fixed round the back of the bass drivers. OK, this made them slightly boomy - flick a 9V battery on their terminals and you get "bink-b*nk". Ideally you want "tick-tock" and the way to do that is to tune the port. I did it by stretching some weed stop membrane (any cheap cloth tends to work) over the rear of the ports and securing it with strong rubber bands. The bass/mid driver isn't sufficiently low Q to get "tick-tock" but they sounded better balanced so in the weed block stayed. And then it was back to speaker placement. They're not bad back to a wall and set like nearfield monitors they worked great with some music, and equally not great with other music. So, here they are in the best listening position yet, and upside down to boot. The grilles are on because otherwise there's a nasty shout and the grilles help disperse it. Next week I'm hoping to receive some BBC Harbeth Monitor 20's (re-jigged LS3/5a's) - another shoebox design but this time they're a sealed box. As they're designed to go back to a wall (in a broadcast truck) I also ordered some Sonex tiles to stick behind them... The "fun" begins all over again  ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Replies:
Posted By: Fatmangolf
Date Posted: 15 Jul 2011 at 12:04pm
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Great photo and post, full of insights and great tips. Fixing the room by moving furniture and fixing the speakers as well. What's behind your desk, is it a blank wall or similar to the shelves and bins behind the speakers?
"The "fun" begins all over again
 " is hi-fi appreciation in a nutshell!------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: Guests
Date Posted: 15 Jul 2011 at 7:52pm
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Oh Dear, no Leaks :o(
Last photo had the Leaks in place ;o)
Adrian.
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Posted By: tg [RIP]
Date Posted: 16 Jul 2011 at 3:51am
Another cabinet leak ? - this time at GSP HQ 
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Posted By: Graham Slee
Date Posted: 17 Jul 2011 at 11:40am
Hi Adrian, They're large speakers, almost the size of my old 2x12 cabs I used for disco work. They sound really nice. The problem I have is that the tweeters are offset and not offset opposite ways for left and right. With my limited space I wasn't able to set them apart sufficiently and far enough away such that the sound from both drive units merged together. I got the treble leaning to the left as such and wasn't able to obtain a stable stereo image. In a larger room they'll score highly I'm sure. At that point I thought I'd try and find them a good new home and offered them for what I paid (just £50 for 4 speakers - two of which have upgraded crossovers - no charge for that), and put them in the "free-ads" section.  (a picture of somebody else's sandwiches picked up on a google search) Since then you kindly sent me the instructions the previous owner had found. It mentions they are designed for floor mounting back to a wall which I can do, albeit under the worktops. I'm going to try this as soon as I can get John to bring me our drum of speaker cable which he keeps in his workshop. It will be interesting to discover if this placement yields the sort of image I've heard with other floor-standers. If the results are acceptable then I'll be withdrawing the ad and writing more about these 1960's classics here. Graham ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
ABPest wrote:Posted By: mrarroyo
Date Posted: 17 Jul 2011 at 1:38pm
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Graham, if you could flip the front wood then you would have a mirror once the drivers are re-mounted. Don't know how much work is involved but ... ------------- Miguel |
Posted By: Graham Slee
Date Posted: 17 Jul 2011 at 2:18pm
That, or something along the same lines, could be the solution I end up with. ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Guests
Date Posted: 17 Jul 2011 at 4:52pm
It's a good job we find these things interesting 
Adrian.
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Posted By: Graham Slee
Date Posted: 17 Jul 2011 at 8:34pm
OK Adrian I've incorporated the Leaks... I disconnected the Leak tweeter and put the Usher 520's on top wired with a simple crossover cap to make them into the mid and tweeter section (wow! a three way system!), the Leaks handling the lows up to 1200Hz where their own crossover cuts.  This is my back wall in answer to Fatmangolf.  ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Graham Slee
Date Posted: 17 Jul 2011 at 8:37pm
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In addition to the above, both the Leaks and the Usher's are mounted upside-down: a] so the Leak bass driver isn't hidden behind my desk and b] I find the Usher's sound better upside-down. ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Guests
Date Posted: 17 Jul 2011 at 9:28pm
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I don't know where to start with this
Do we all have to listen to our speakers upside down now
 or stand on our heads for that last bit of emotion Good to see the Leaks back in use.
Was it raining today?
 How does it sound now?
Adrian.
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Posted By: Fatmangolf
Date Posted: 17 Jul 2011 at 10:39pm
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I like listening to speakers, but it does take ages to get the setup right. Headphones are easy by comparison.
Thanks for the picture Graham, I appreciate it sounded like a weird question! I can see why you've gone for nearfield, and why that made the poor crossover parts tiresome.
Jon ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |
Posted By: ServerBaboon
Date Posted: 18 Jul 2011 at 11:56am
Oh and listening in pitch darkness as well .. .. on a tangential note went to the below concert by Amadou and Mariam (blind Malian couple) which was in complete darkness and you did apreciate the sound even more even if you do lose some of the shared experience. http://mif.co.uk/event/armadou-mariam-eclipse/ - http://mif.co.uk/event/armadou-mariam-eclipse/ ------------- Steve ------------- Various bits of GSP Kit ..well two so far, unless you count the cables that is. |
Posted By: Graham Slee
Date Posted: 18 Jul 2011 at 1:48pm
Well, it's just started to get serious... L/R balance on the LF drivers is -3dB/0dB measured on my SPL meter. Last night I thought the image was over to the right. No need for darkened rooms or standing on one's head - I'm dealing with this in the light of day (even though it could be dark outside...) ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: ServerBaboon
Date Posted: 18 Jul 2011 at 5:08pm
Are we talking about the Leaks now or the Ushers or the whole ensemble? ------------- Steve ------------- Various bits of GSP Kit ..well two so far, unless you count the cables that is. |
Posted By: Graham Slee
Date Posted: 18 Jul 2011 at 7:49pm
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Leaks. Removed tweeters and blanked off holes, they are now within 1dB. Mounted tweeters separately, with pink noise they were up 6dB above LF units - in need of attenuation - next job...  ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Graham Slee
Date Posted: 20 Jul 2011 at 9:22am
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As I may or may not have mentioned, speakers are something I used to enjoy, DIY build, install and actually use myself. It's only really been the last 10 years since moving to this semi-attached single storey house with cinder-block party-walls having many unfilled joints lurking under the plaster, that headphones have ruled. Ideally the structure of our homes should attenuate all frequencies by around 60dB to ensure peace and quiet both ways, but the vast majority don't, and believing "love thy neighbour as thy loves thyself" should act both ways... Now, unfortunately, low frequencies are very difficult to tame. And there's a reason for that: it's to allow elephants to communicate over vast distances (it's a good job the elephants that live in the UK are kept in zoo's or we'd have a lot of very dead occupants of squashed cars... and this is probably why Hi-Fi isn't as popular in South Africa...) The point I'm trying to make is that bass is the hardest sound to attenuate in building structures and beyond. When low powered amps were the norm many years ago it may have been OK to stand speakers on the floor and push them back to the wall to gain more acoustical output at low frequencies, but today, with high powered amps, we really need more than ever to consider others (although often it would seem the opposite is taking place). Speakers on properly designed stands can decouple the bass from the structure so that we only have to deal with airborne noise (and repairing the floor when the other half discovers the mess the spikes have made...). So when we get a pair of 1960's speakers like the Leak "Sandwich" and support them appropriately, away from the wall the intended bass output drops. What also happens is the tweeter output stays the same, so the sound balance is terrible! Therefore, I decided to measure the comparative outputs of bass and treble drivers using a test record having a pink noise track and an installers sound level meter. I found the tweeter's output to be +6dB SPL at 1 metre (sound pressure level) compared to the bass driver. What to do? Obviously the tweeter requires attenuating. This has to be done without upsetting the crossover turnover frequencies so the attenuation needs to result in the same impedance load on the crossover. This is done with an "L-pad" attenuator which is a posh way of describing a potential divider. As we are dealing with power here, we could think +6dB is four times the output (3dB being times 2 in power terms) but in sound pressure terms we find +6dB is the same as with signal voltages: twice in other words. I made up a rudimentary "L-pad" to do -6dB to correct for the tweeter's output, measured it with the meter and found it to be flat. Now, all this is with the cabinet in disarray as the tweeter's were out and stood atop the cabinets. One good thing is that tweeters don't rely on a sealed box or ports and things to work near to proper. But when mounted onto the "baffle" (front panel), the pressure wave they generate will be reinforced so you expect the acoustic output to go up. Auditioning therefore has to have the final say. And with a sub-baffle attached there was a bit more "life force" to the music - vocals were fuller rather than being recessed as they were with the tweeters stood by themselves. So, that's where I'm up to as I type. I have provided a gaping cutout in the existing baffle board above the bass driver to take the rear of the tweeter, which will be mounted on a sub-baffle with its "hat" sealing it off from the rest of the cabinet, which, in turn, will be screwed to the existing baffle. The tweeter-offset to the same side - both cabinets - has been remedied so they are central above the bass driver - this should ensure better imaging. There will, I'm sure, be all sorts of reflections because of the 5/8" step between sub and existing baffle, but then again, the improvements should be better output matching and a centralized image, so I'm willing to listen through such imperfections which may well turn out to be minor. The whole lot will look ugly but the original product looked almost as bad with grille removed. If I can unpick the grille material I will make a hole in the grille board to align with the tweeter's new position and use them with grilles on. The grilles should disperse any less-than-forgiving reflections as mentioned above. Here's the picture of where I'm up to (below), and the proper L-pad resistors have just arrived so I'm going to get busy and get these modified Leak "Sandwich" two ways finished ASAP. (the speaker on the right is shown with tweeter "hat" positioned where it should eventually reside) 
------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Guests
Date Posted: 20 Jul 2011 at 9:42am
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I really must apologise for all the work I have created for you Graham
Adrian.
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Posted By: Graham Slee
Date Posted: 20 Jul 2011 at 1:38pm
If it were not for Leak using tar board for cabinet damping it would have been more of a "pleasure". The moment you drill or saw into tar board, it smears and clogs the drill flutes and saw teeth. The only remedy is by soaking the cutting tools in white spirit. However, think of the cost of decent monitors! Something this size like the Harbeth monitor 40 costs over £6K per pair. The smaller monitor 30 is around £2K. If we take an average of these prices we're talking about £4K and we don't come across that sort of money easily. Having said that, as a check measure, I have ordered the shoebox size Harbeth monitor 20's at just over £1K. So what's all the fuss about speakers at HQ? The Proprius power amp of course - we need to ensure it truly delivers before we dare think about manufacturing them. ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: tg [RIP]
Date Posted: 20 Jul 2011 at 4:44pm
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Are you going to send a pair to Geoff Husband to review? |
Posted By: Graham Slee
Date Posted: 20 Jul 2011 at 11:26pm
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@ tg, at least I hope Geoff will want to listen to the amps. And now the results of the last couple of days of frantic work...  The Sandwich Leak should have made! ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: mrarroyo
Date Posted: 21 Jul 2011 at 12:18am
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Nice work there Graham, hope you enjoy them as much as the more expensive Harbeth you ordered. ------------- Miguel |
Posted By: tg [RIP]
Date Posted: 21 Jul 2011 at 5:52am
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That's a pretty good looking result, hope the listening tests confirm the benefits of all that effort. I will be most interested if GH does give the amps a run. His Polaris are a larger version of my speakers and use the same driver. |
Posted By: BAK
Date Posted: 25 Jul 2011 at 3:11pm
| Graham, Nice retrofit for vertical alignment. How do they sound now? |
Posted By: Graham Slee
Date Posted: 28 Aug 2011 at 11:04pm
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Hello BAK, quite acceptable on most albums. But before going into that further I have some other news... The Harbeth "BBC" Monitor 20's turned up on Friday, as well as 2 Sonex Willtec acoustic tiles I had ordered. I had ordered the M20's mid July but the wholesaler was out of stock. After 6 weeks I ended up calling Harbeth who explained that their order book was full until April 2012, but a good chap called Andy said he'd put my order through the very next day and get them shipped overnight to the wholesaler. This duly happened - thanks Andy!  First impression? I'm quite amazed! As I type my left ear is 2 feet away from the right hand speaker and 5 foot away from the left hand speaker, but I'm hearing a stereo image! These speakers made it a doddle to sort out exactly where the Willtec acoustic tiles should go for the best sound and image. More on this and pictures to follow.  ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: mrarroyo
Date Posted: 29 Aug 2011 at 11:08am
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Look forward to the pics and additional impression. ------------- Miguel |
Posted By: Graham Slee
Date Posted: 29 Aug 2011 at 8:07pm
Pictures of the M20's... The printer and filing cabinet didn't cause any acoustic problem but the ceiling and door (to the left) did. This was sorted by sticking Sonex Wiltec tiles on to same. Without the ceiling treatment the image was the same height as the security camera monitor causing me neck ache. Now it's the same height as the M20's. The speakers do nothing - the sound is on a separate sound stage  A shoe box it may be but it definitely doesn't need a subwoofer!  Hooked up using 325/0.1 cable which just fits the 2 pole Neutrik Speakon OK, they're not cheap: 1,110.00 GBP wholesale! But our customers are worth it. ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Cyreg
Date Posted: 29 Aug 2011 at 10:21pm
Hi Graham, been some time, congrats on your Harbeth M20's. 
Not very efficient, but the electrical load should be not very difficult.
Feels to me like a good reference for designing/testing your poweramp.
I do use the commercial variant of the M20, being the Harbeth P3ES-2.
It's used in my livingroom TV/Radio setup with the smallest NADamp(C316BEE)
Harbeth Compact 7ES-3's are used for listening to music in a different room. ------------- TecnoDec/RB250/MP110>GramAmp2C/PSU1; Cyrus CD8SE; Cyrus FM7 > Exposure XXXV > Harbeth C7ES-3 '35th Anniversary' cabling: IC 3x DNM V3; LScable Exposure DMF-two; Furu TP60 + MWaY and AH! powercords |
Posted By: franklin
Date Posted: 30 Aug 2011 at 1:13am
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As Mr Slee mention sub woofer. I have a little experience
like to share. Few years ago I had a pair Harbeth P3ES on my desk. They were working with my computer system. And one day I want to try a sub woofer. I found myself a REL sub woofer, which is a 8" cone with a closed enclosure. I put it under my desk and the performance was pretty good. This setup can trick my ears to believe the bass is coming from the Harbeths. The setup wasn't difficult. I just find the right phase, and tune the cut off frequency intuitively. |
Posted By: Graham Slee
Date Posted: 30 Aug 2011 at 8:39am
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Thank you Cyreg and franklin. I had thought of getting the P3ES-2 but went to my pro supplier thinking it would be easier and faster... six weeks late and I'm running behind schedule, oh hum... I thought I'd got the set up right then in wandered my 12 year old son Ryan. He spots invisible speakers for me...  "Invisible speakers" are reflections and Ryan's hearing must be like a bats! As you can see, he's searching for the reflection and it's coming from the flat screen monitors. He doesn't like reflections because they confuse the sound stage, and I don't either but it's harder for me to find them. Well done Ryan! I now have to order some more Sonex tiles and I'll probably have to make screen covers or just prop a full one in front of the computer monitors when listening. Problems, problems. This is why I called this topic "I hate speakers". ------------- That none should be able to buy or sell without a smartphone and the knowledge in how to use apps |
Posted By: Fatmangolf
Date Posted: 05 Sep 2011 at 10:15pm
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Great photo and explanation as always. Very good hearing and love of music clearly runs in the family! Helpful tip. Looking at the visual reflections can be helpful, try temporarily placing a plastic mirror or some foil on any matt surfaces to see if you can see a speaker in the reflection.
Graham, have you tried rotating the monitor away from the speakers? It may help to eliminate the reflection/invisible speaker without needing a screen cover which could still reflect midrange.
Jon ------------- Jon Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC. |