Film-Tech Forum ARCHIVE: Speaker and Amp recommendations

This is topic Speaker and Amp recommendations in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=002400

Posted by Christopher Lani (Member # 7952) on 09-01-2015, 01:58 AM:

I am thinking of replacing my much used EV behind screen speakers, mains, horns and subs. Any likes or dislikes in terms of brands?

Posted by Jack Ondracek (Member # 1466) on 09-01-2015, 09:02 AM:

Unfortunately, like your "The Best" topic, this one is difficult, if not impossible to answer. The best speaker system would be selected after evaluating where they would ultimately be installed.

Speaker systems are designed to deal with a specific range of characteristics. Within those constraints, some installation and servicepeople will suggest their "favorites", while others will take a more scientific approach to what speaker they think would be best for you.

You probably won't get the answer you're looking for, asking the question in the way you have. Even posting the models of the speakers you currently have wouldn't be good enough, since those might not have been appropriate for your theatre in the first place.

My opinion is you need an on-site visit by a qualified tech, if not a couple of them.

Posted by Sam D. Chavez (Member # 1841) on 09-01-2015, 09:43 AM:

In answering your question with a question, how much money do you want to spend? New or used? There's plenty of used JBL and EV around. Also QSC amps.

Posted by Christopher Lani (Member # 7952) on 09-01-2015, 12:14 PM:

Let's not over think this one Jack. Sam, you're on the right track. I have a barrel style art -deco theater with about a 100' throw. I currently have some very old QSC amps powering everything. I would not be opposed to used equipment and have had no problems with my QSC's, its just time to upgrade. My budget is about $3k. Could go up to $6k if necessary. I know it seems vague to you Jack, but I am just asking for some informed opinions about some of the available brands that are out there and if there are any I should avoid. For example, my EV speaker's have needed multiple repairs to the holding rings that attach the speaker cone to the cabinet. I have had to completely contact cement just about every cone in every speaker. I was told by our tech that this was a problem with this specific model of speaker. Sam, are there any surplus stores that specialize in used speakers that you would recommend? My system was upgraded in the early 90's by the now Vice President of Ultra-Stereo. He was a tech at the time and was very helpful when my original Ultra-Stereo gave up the ghost. Having done sound for a few years for music, I know that there are specific speakers, amps, XLR cables, etc. that have reputations for being reliable and bullet proof. Just wondering if any one has any recommendations.

Posted by Leo Enticknap (Member # 534) on 09-01-2015, 12:28 PM:

Agreed completely with Jack that this is really a broader question, but why not start with an even more fundamental one: what is your audio system not doing that you'd like it to do, is there a business case for upgrading and if so, what's the best way to upgrade?

If you're going to start by asking for professional advice, the professional needs to know what your goals and budget are in order to be able to deliver the right advice.

For a few months after first arriving in the US, I sold archival film scanners. The needs of, say, UCLA wanting to scan reels of nitrate features in 4K as the first step in a full-scale restoration are very different from those of a mail order "Your old super 8 home movies transferred to DVD" business. The former will want the highest possible quality of output, but speed and ease of operation are less important. The latter will need it to scan 10,000 feet a day while being looked after by a minimally trained operator, but won't need the flexibility to adjust the timing, gamma curve etc., of each individual frame, or sophisticated digital restoration software tools bundled with it.

So if an enquiry began with "I see that your scanner has this cool feature; please tell me more about it," my response would be to ask about the inquirer's business and what (s)he needs out of a film scanner in the round, not just in relation to that one feature. If you're contemplating a major investment in capital equipment for your business, a fundamental look at why you're considering a big spend and what you expect that investment to deliver is essential.

Posted by Mark Gulbrandsen (Member # 72) on 09-01-2015, 02:34 PM:

I'd stay away from used EV for sure or any speaker that uses foam surrounds on the woofers. EV stuff is much more difficult to get parts for now and expensive re-cone and or re-foam repairs will ensue. I have a theater in Idaho that is full of deteriorating EV woofers we are cycling out. And the high end response of E-V was never too impressive, although their large horn was excellent if you used a JBL driver on it.

Used JBL stuff, sure. It's ok and easier to get repaired and less likely to need repairs unless you end up with woofers that have foam surround. They made a few with that too.

I don't even bother with used any more, or new JBL because they have virtually zero cinema support in the USA since Lynn Dean retired. The stuff is questionable and a lot of it now comes from China.

Now, everyone gets new QSC speakers. They're made in CA, have great tech support and will help to ensure you get the correct speakers for your particular auditorium. BTW: 100' throw is going to require large horns or big systems so you have decent HF coverage front to back or dialog is going to suffer.

Mark

Posted by Marco Giustini (Member # 4544) on 09-01-2015, 05:02 PM:

Everyone!

Posted by Louis Bornwasser (Member # 3063) on 09-03-2015, 06:56 AM:

Mark is right/ At one time you could buy a JBL replacement for the cost of reconing an EV. Not only that, but it was a forever fix with one way freight. You won't go wrong with a used JBL 4675.

Lyn Dean did not retire. She fought too hard for her customers.

Posted by Steve Guttag (Member # 268) on 09-03-2015, 09:25 AM:

As a "former" EV factory authorized reconer...I don't know what you are talking about. EV recones were the cheapest BY far of the larger brands. Furthermore, one could piece-meal the entire recone kit as much as one wanted. They were far cheaper to recone than JBL. JBL pre-assembled their recone kits into what is known as an "C" kit such that the v.c. spider, cone are all pre glued together. This works because JBL has a high degree of precision on their drivers. All one has to do is check the air gap on the pole piece to ensure it is within tolerance. With EV, it is an "A" kit where nothing is put together. One has to have fixtures for every type of driver/kit they want to assemble. The advantage there is not only cost (the manufacturer doesn't have to assemble anything beyond the v.c. windings on the v.c. former or the compliance on the cone, that via the fixture, the cone will be exactly centered to how the driver, such as it is, is made. It is an exact fit when you are done.

We only got into doing EV cones because we have historically done Altec...when Alec was with EV no more, there wasn't much need/call to do EV...we ended up mostly doing DJ stuff for them after a while (or low-end band speakers). Altec, for what is worth uses a process "B" kit where the spider and v.c. are pre assembled but the cone is separate so you get a degree of customization since the frame/basket may not be as precise as the magnet structure.

Posted by Mark Gulbrandsen (Member # 72) on 09-03-2015, 11:41 AM:

Louis, Lyn did indeed retire... And JBL Cinema pretty much retired with her. Yes, JBL does still make some acceptable products, but there are now other products available that are much better then JBL's 40 year old designs. EV isn't evven a relative factor any longer in this country.

Mark

Posted by Steve Guttag (Member # 268) on 09-03-2015, 02:28 PM:

VERY little of the JBL 35ish year old designs are still offered. The 4670 and 4675 are gone.

Posted by Hector Perez (Member # 9044) on 09-07-2015, 11:15 PM:

Hello guys, that's my firts post, im new here, It is a pleasure to write in this forum, excuse my English is not very good hope you can understand.

Well, i´ll would like to give my opinion, the sound it is very important for me.

Before choosing the speakers it is very important to know that there are some calculations that you do to make your room sound very well. First, you must keep in mind the throw, I read that is 100 m, why throw it is important? Because the sound pressure level (SPL) is lost in the distance, and this forces us to give more gain and force the speakers and this creates distortion and also damage it, causing further investment in the repair of the speakers, with a throw of 100 m to a loss of 40 dB SPL, but something happens rules said that you have 102 dB SPL 2/3 of the room without harmonic distortion, 2/3 of the room are 75 m, then lose 37.5 dB.

How to know if the the speaker recommended me is the ideal

For example the Cinema speaker Klipsh KPT-MCM-II-Q

Sensitivity: 108 dB, 1W to 1m measure pink noise.
Power handling: 1155W
Total sensitivity: 138,6 dB, 1155W, 1m measure pink noise.

And now, if we have a speaker of total sensitivity 138.6 dB and the way to lose 37.5 to 75 m the SPL would be 101.1 dB.

Maybe that can help you, or other person in this forums can reforce.

Regarts

Posted by Mark Gulbrandsen (Member # 72) on 09-08-2015, 11:59 AM:

quote: Steve Guttag
VERY little of the JBL 35ish year old designs are still offered. The 4670 and 4675 are gone.

That's too bad! Those were a couple of the better designs except for the two very large 3-way systems. The Screen Disarray stuff is crap.

Mark

Posted by Steve Guttag (Member # 268) on 09-08-2015, 12:43 PM:

I'll take a 4722 over the 4670 any day. The 2380 horn was not very good...very poor pattern control and a joke trying to crossover at 500Hz. Yes, it could do it but it wasn't graceful below 1K.

The 4675 was definitely a great speaker though. Its always a happy day when one of those is behind the screen. You know it is going to tune up, and more importantly, sound good.

Posted by Marco Giustini (Member # 4544) on 09-08-2015, 05:13 PM:

Hello Hector

Welcome to the forums. I believe the throw was 100', which should be 100 feet - 30 metres. I still have to walk into a 100 metres long theatre!

Also, the peak SPL at listening position shall be 105dB. 102 is used for surrounds.

Posted by Mark Gulbrandsen (Member # 72) on 09-08-2015, 09:06 PM:

The 4670D which I used some of in the 80's and 90's was fine in short throw auditoriums that were not over 40' long or more than 30' wide. It crossed over at 800 HZ, not 500 hz. There is no way that horn could do 500hz...

Mark

Posted by Steve Guttag (Member # 268) on 09-09-2015, 06:41 AM:

Read the 2380 specs...it was rated down to 500Hz and it had NO pattern control over 1000Hz. While people did use an 800Hz crossover to try and help it, it remained a miserable horn and was not suited to 40' throws anymore than it was suited to 70' throws. They only reason people used it was due to space limitations behind the screen, cost or a complete lack of understanding of why it was such much more inferior than the 2360. After all, on the surface, there was no difference in the 2360 and 2380...both had the same effective horn coverage and same crossover point...it is only when you dug deeper that one finds why it was vastly inferior.

If you want to read about it...you need look no further than the spec sheet:

https://www.jblpro.com/pages/components/2380ser.htm

After looking at it...I need to amend my statement...it has no pattern control blow 2KHz! (in truth, it gets its pattern control somewhere between 1K and 2K).

Conversely, the Altec MRII594A did small flat-front horns right:

http://www.greatplainsaudio.com/vintage_altec/MRII594A_hfhorn_spec_sheet.pdf

It had pattern control (and response) down to 500Hz...a FAR superior horn (and more uniform coverage)

Posted by Hector Perez (Member # 9044) on 09-09-2015, 11:06 PM:

You´re Right Marcos, 105 dB Frontal Speakers, 102 dB Surround Speakers and (my own calc for Subwoofer Speaker are 113 dB [Wink]

if you have a recommendation for the calculation of the subwoofers, I will know to appreciate)

in my Mind, i was thinking, i want to know that´s Theater, 100 m, I couldn´t believe it, and It is unthinkable. hehehehe...

in 30m lose 29,5 dB, but 2/3 are 23m more and less, well then lose 27,2 dB.

Christopher, this Speaker maybe can serve you, but do you need an on-site visit by a qualified tech.

Frontal JBL 5742
Subs 4 X JBL 5628

Posted by Marco Giustini (Member # 4544) on 09-10-2015, 01:17 PM:

Hector, in the digital world the sub is now 115dB. I understand that 113 was used when dolby digital was around.

Posted by System Notices (Member # 2357) on 10-03-2016, 11:45 AM:

It has been 388 days since the last post.

Posted by Tom Wienholt (Member # 1510) on 10-03-2016, 11:45 AM:

When setting up a 7.1 system, can different model surrounds be used for the rear surround channels and the side channels? Basically there will be 2 speakers each for the rear channel and 4 each for the side channels. I will need higher powered surrounds for the rear since there will only be 2 per channel.

Posted by Sam D. Chavez (Member # 1841) on 10-03-2016, 01:36 PM:

You would need a 4 channel amp to address this mismatch in a satisfactory way.

Also, it might be possible depending on location of the rearmost side surrounds to add them to the back surround strings.

Posted by Tom Wienholt (Member # 1510) on 10-05-2016, 05:16 PM:

Yes, I am aware that additional amp channels are required. But, I am asking if it would be OK to use higher powered surrounds for the rear surround channels since there will only be 2 speakers for each of the rear channels?

Posted by Dave Macaulay (Member # 813) on 10-05-2016, 07:16 PM:

For me the question is how wide the back wall is. You want a "wall of sound" not easily discernible point sources (opinions differ, see Imax practice). I like to have speakers max 8ft apart. More smaller ones in a really small room.

Posted by Sam D. Chavez (Member # 1841) on 10-06-2016, 01:59 AM:

quote: Tom Wienholt
Yes, I am aware that additional amp channels are required. But, I am asking if it would be OK to use higher powered surrounds for the rear surround channels since there will only be 2 speakers for each of the rear channels?

Your question does not have a simple answer. You can put more powerful speakers on the back wall but they need to be set to the same SPL as the side channels. More important, do they sound like the ones on the sides, as I'm timbre. This is usually close if you stay to the same brand and style as the sides, assuming the side speakers are "good" and in good condition.

I agree with Dave here. You are very short on details for anyone to be truly helpful and you fail to understand we are trying to guide you, while you want oversimplified yes/no answers and seem annoyed at followup questions.

Posted by Tom Wienholt (Member # 1510) on 10-07-2016, 04:59 PM:

Sam, thanks for the response. The room in question is 38' wide and 55' long with 21' ceilings. There are 4 surrounds on each side wall spaced 10 feet apart. There are 4 surrounds on the rear wall (2 per rear channel) spaced 8' apart. I was just curious if anyone had used higher power handling speakers on the rear wall, compared to the side channels (same manufacturer of course).

Posted by Sam D. Chavez (Member # 1841) on 10-08-2016, 12:33 PM:

Since the back surrounds are directly behind people's heads you have the set the level the same as the side speakers, 82 dB or 85 depending on the processor, the higher power may go to waste. The real question for any surround speaker array or "zone" is will it produce 100% modulation which is around 102dB without blowing up. That involves a bit of math and has to start with the power rating of the speaker, its efficiency, for example (95dB@ 1 Meter/1 Watt) and the amplifier power. You calculate the sound pressure level at the desired seat which might be 40 feet away. As a guide, it's a 6 dB drop every time you double the distance from the speaker, 2 meters, 4 meters, 8 meters, etc. This will tell you power required for the amplifier and the speaker array or zone. Don't be surprised if the existing side speakers won't meet this spec.

Now with Atmos, each speaker in the surrounds would have the meet the standard above.

Have fun. Guttag will be along to correct my math if he's in earshot. He always does.

Posted by Jarod Reddig (Member # 6363) on 10-09-2016, 07:32 AM:

All digital and no film make Film-Techers some dull boys. Me too but its almost my fav time of year.

Go to QSC website and click solutions and choose the one that fits your room size best. Then make calls to reps or ones from reps past and find the best deal. Get it installed and EQd and your set. Mid-sized room solution on there may be your best bet with budget. Won't have to buy another system for many wonderful years just some minor upkeep.

JBL? 3 used 4675 as said, 8340(a) or 8350(a) surround minimum 12 if using 7.1. 4 per wall has worked well in many theaters ive visited. One in a small town Ive seen many a classic at used two surrounds per wall and they had a balcony so all surround effects went unnoticed. Or in my case I noticed I didn't notice them

Posted by Gordon McLeod (Member # 33) on 10-09-2016, 09:18 AM:

Surrounds are supposed to be a non-directional non point source so i always prefer a large quantity of smaller speakers spaced closer together so there is no actual locating which speaker giving a diffuse and even coverage

Posted by Sam D. Chavez (Member # 1841) on 10-09-2016, 10:21 AM:

While Gordon is correct that it should be a diffuse field, it should at minimum be able to discern let wall, left back etc., i.e. 4 zones.

Atmos takes off from there.

Posted by Gordon McLeod (Member # 33) on 10-09-2016, 05:40 PM:

the old Altec rule was the speaker height off the floor was the distance apart

Posted by Mark Gulbrandsen (Member # 72) on 10-10-2016, 03:52 PM:

There are computer programs now that are used. If you do not have one or access to one just ask QSC to do it for you.

Mark

Posted by Gordon McLeod (Member # 33) on 10-10-2016, 04:41 PM:

http://www.integralacoustics.ca/